International Orthopaedics (SICOT) DOI 10.1007/s00264-015-2849-9
ORIGINAL PAPER
Surgical site infection in hand surgery Mariano E. Menendez 1 & Na Lu 2,3 & Sebastian Unizony 3 & Hyon K. Choi 2,3 & David Ring 1
Received: 19 March 2015 / Accepted: 21 April 2015 # SICOT aisbl 2015
Abstract Purpose As ambulatory surgery becomes increasingly common, there is growing interest in assessing, monitoring, and tracking complications that occur secondary to outpatient procedures. We sought to determine the rates of 14- and 30-day acute care visits for surgical site infection after outpatient hand surgery, and to identify associated factors. Methods Using the California State Ambulatory Surgery database for 2010 and 2011, we identified 44,305 patients undergoing common outpatient hand surgery procedures. Cases were linked to the State Emergency Department and the State Inpatient databases for postoperative acute care visits (e.g. hospitalizations, emergency department or ambulatory surgical visits) related to surgical site infection. Results Postoperative acute care visits for surgical site infection occurred in 1.7 per 1,000 hand surgery procedures (0.17 %) at 14 days, and 3.3 per 1,000 (0.33 %) at 30 days. Thirty-day infection rates were lowest after ganglion cyst (0.15 %) and deQuervain surgery (0.25 %), and highest following cubital tunnel release (0.56 %) and trapeziometacarpal arthroplasty (0.49 %). Fifty-three percent of postoperative visits were treated in the emergency department setting, Level of evidence: Level III, Prognostic study * David Ring [email protected] 1
Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Yawkey Center, Suite 2100, Boston, MA 02114, USA
2
Clinical Epidemiology Unit, Boston University School of Medicine, Boston, MA, USA
3
Rheumatology Allergy and Immunology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
37 % in the inpatient setting, and 10 % required an additional outpatient surgical procedure. Patients with governmentfunded insurance—Medicaid in particular—and those residing in rural areas had higher odds of postoperative acute care visits for surgical site infection. Diabetes, obesity, and tobacco use were not associated with increased risk for infection leading to an acute care visit. Conclusion The rates of postoperative acute care visits for surgical site infection after ambulatory hand procedures are low but not negligible—particularly given how common hand surgery is, and the fact that many of these events entail hospitalizations or additional ambulatory procedures. Reasons for the increased risk of acute care visits for infection among publicly insured and rural patients merit additional research. Keywords Surgical site infection . Hand surgery . Complication . Patient safety . Quality improvement
Introduction Surgical site infections (SSIs) are associated with substantial morbidity and resource utilization, and inevitably result in prolonged recovery and lower quality of life [1–5]. With increasing emphasis placed on improving patient safety and quality of care while constraining costs, reducing SSIs has become a priority for both policymakers and clinical leaders [6]. In 2008, to promote and accelerate strategies to prevent healthcare-associated infections, the Centers for Medicare and Medicaid Services (CMS) began denying reimbursement for SSIs after selected inpatient surgeries [7, 8]. In that same year, the US Department of Health and Human Services established the National Action Plan to Prevent Healthcare-Associated Infections [9]. This plan initially focused on preventing SSIs
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after inpatient surgery but subsequently broadened to encompass outpatient surgery [10]. Although nearly two-thirds of all surgeries in the United States are now being performed outpatient [11, 12], research on SSIs is largely confined to the inpatient setting [13–18]. A recent population-based study by Owens et al. [6] emphasized that SSIs are also common after ambulatory surgery. Hand surgery is common, but there is limited research about the incidence and correlates of SSI in this setting [19–22]. The available data are mainly derived from single institutions, focus exclusively on one procedure (e.g. carpal tunnel release), and do not contain enough infections to conduct meaningful statistical analysis [19–22]. Given that even seemingly trivial SSIs following hand surgery can have important clinical and economic consequences [4, 23–25], a better understanding of their incidence and associated factors might prove useful for better allocation of resources and implementation of preventive strategies. To address this gap in knowledge, we calculated population estimates of 14- and 30-day acute care visit rates (e.g. hospitalizations, emergency department or ambulatory surgical visits) for SSI following common outpatient hand surgery procedures. In addition, we identified potential predictors of SSI after hand surgery.
ambulatory surgery—by linking the initial encounter data to the corresponding State Inpatient Database (SID) and State Emergency Department Database (SEDD). This study was exempt from review by our Institutional Review Board because the data are publicly available and contain no personal identifiable information. Study sample We initially considered all ambulatory surgery records for patients undergoing common hand procedures between 2010 and 2011. Using CPT codes, combined with ICD-9-CM diagnosis codes for procedures with less-specific CPT codes, we selected seven hand surgeries: carpal tunnel release (CPT code 64721), trigger finger release (CPT code 26055 and ICD-9CM code 727.03), wrist ganglion excision (CPT code 25111), cubital tunnel release (CPT code 64718 and ICD-9 code 354.2), Dupuytren surgery (CPT code 26123 and ICD-9-CM code 728.6), de Quervain surgery (CPT code 25000 and ICD9-CM code 727.04), and trapeziometacarpal arthroplasty (CPT codes 25445 or 25447). Patient demographic variables consisted of age, sex, primary health insurance, and residential area. Outcome measures
Materials and methods Data source and study design Encounter data for this retrospective cohort study were abstracted from the California State Ambulatory Surgery Database (SASD) for 2010 and 2011 [26]. This dataset is part of the Healthcare Cost and Utilization Project (HCUP), an initiative operated by the Agency for Healthcare Research and Quality. The California SASD collects all-payer encounter-level information on surgical procedures performed in ambulatory settings, with no overnight inpatient stay. These encompass surgical suites within a hospital as well as hospitalaffiliated and freestanding surgical facilities. Procedures performed in physician offices are not included in this dataset [6]. The SASD utilizes the Current Procedural Terminology (CPT) codes to standardize the reporting of up to 21 surgical procedures, and the International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] codes for the reporting of up to 25 medical diagnoses. We chose California because it is one of the larger and more ethnically diverse states participating in the HCUP, and is currently the state with the second greatest number of ambulatory surgery facilities [26]. Through the use of unique encrypted patient-level identifiers, we tracked patients over time and across different hospital settings—inpatient, emergency department, and
The primary outcome of interest was the rate of postsurgical acute care visits for surgical site infection (SSI) following each of the selected hand procedures. Postoperative encounters for SSIs were identified using a validated algorithm that employed ICD-9-CM diagnosis or procedure codes and CPT codes (Appendix 1) [6]. The denominator was the number of hand surgery procedures, and the numerator was the number of those procedures that resulted in at least one subsequent emergency department (ED) visit, ambulatory surgery visit, or inpatient stay for a SSI within 14 or 30 days [6]. Patients with more than one subsequent visit during this time period were counted only once in the numerator. We included ED visits because, unlike other musculoskeletal procedures such as total joint arthroplasty or spinal laminectomy, we suspected that many SSIs after hand surgery would not require an inpatient admission or an additional outpatient surgical procedure. Patients with SSIs who made postsurgical visits to physician offices were not captured. The rates were reported per 1,000 surgical procedures. We also computed rates of postoperative visits for all causes (including SSI) in order to evaluate the relative importance of SSI as a reason for postsurgical visits. Records for hand surgery procedures performed in January 2010 or December 2011 were excluded to allow a window of 30 days before and after surgery to assess other hospital visits (n=4,737). In order to select a homogenous cohort of adult patients at low surgical risk, we excluded patients aged less than 18 years old (n=2,148), patients undergoing more than
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one procedure on the same visit (n=3,232), patients with a non-routine discharge disposition (n=57), and those who had been seen in acute care in the 30 days prior to surgery (n=2,042). We retained 44,305 records for hand surgery procedures (Fig. 1). Statistical analysis We assessed patient demographic characteristics associated with each hand surgery. Overall and procedure-specific observed rates of postoperative visits for SSIs and all causes were determined at 14 and 30 days. Assuming a binomial distribution, we used Jeffrey intervals to calculate 95 % CIs [6]. Multivariable logistic regression modeling was used to identify factors associated with development of SSI after hand surgery. Besides sociodemographic characteristics, we included diabetes and tobacco use in our model, as they have been previously suggested as predictors of SSI in the hand surgery setting [19]. We also considered obesity because it has been associated with higher risk for SSI following other orthopaedic procedures [27, 15]. All covariates were entered into the model simultaneously, without further selection. Besides reporting fully adjusted odds ratios (OR) with 95 % confidence intervals (CI), we presented crude (unadjusted) OR and age- and sex-adjusted OR. Data management and statistical analyses were performed using SAS version 9.3 (SAS Institute, Cary, NC).
Results Patient characteristics The mean age of patients undergoing hand surgery ranged from 53 years (cubital tunnel release) to 64 years Fig. 1 Hand surgery procedures meeting study criteria
(Dupuytren surgery) (Table 1). Trapeziometacarpal arthroplasty (73 %) and deQuervain surgery (71 %) were more likely to be performed on women; in contrast, surgery for Dupuytren contracture (22 %) and cubital tunnel release (39 %) were less likely to be performed on women. More than 90 % of each selected surgery was performed on patients from metropolitan areas, varying from a low of 92 % for carpal tunnel release to a high of 96 % for removal of a ganglion cyst. Seventy percent of ganglion cyst removals were billed to private insurance, compared to only 41 % of carpal tunnel surgeries. Rate of postoperative visits for SSI The overall rate of postoperative visits for SSI within 14 days was 1.7 (95 % CI, 1.4–2.1) per 1,000 hand surgery procedures (Table 2). The 14-day rates of postoperative visits for SSI varied by type of surgery, ranging from 1.0 (95 % CI, 0.30-2.4) per 1000 ganglion cyst removals to 2.5 (95 % CI, 1.1-4.8) per 1000 trapeziometacarpal arthroplasties. The overall rate of all-cause postoperative acute care visits within 14 days was 33 (95 % CI, 32-35) per 1000 hand surgeries, thus indicating that SSIs were the cause of 5.2 % of all postoperative visits. The overall rate of postoperative visits for SSI increased from 1.7 (95 % CI, 1.4–2.1) to 3.3 (95 % CI, 2.8–3.8) per 1,000 surgical procedures when the time frame was extended to 30 days. The 30-day rates of postoperative visits for SSI also varied by type of surgery and ranged from 1.5 (95 % CI, 0.60–3.0) per 1,000 ganglion cyst removals to 5.6 (95 % CI, 3.3–8.8) per 1,000 cubital tunnel releases. The overall rate of 30-day acute care visits for all causes was 56 (95 % CI, 54–58) per 1,000 procedures, therefore implying that SSIs were responsible for 5.8 % of all postoperative visits.
International Orthopaedics (SICOT) Table 1
Characteristics of patients undergoing hand surgery, 2010–2011 California
Type of surgery
Index Surgical Procedures, No. Age, mean (95 % CI), years Number (%) Women
Metropolitan residence Primary expected payer: private
All surgery
44,305
57.2 (57.1–57.4)
25,569 (57.7) 41,680 (94.1)
20,860 (46.3)
Carpal tunnel release Trigger finger release Wrist ganglion excision Cubital tunnel release Dupuytren surgery Basal joint arthroplasty De Quervain surgery
23,109 7,680 4,036 2,867 2,163 2,844 1,606
58.3 (58.1–58.5) 59.9 (59.6–60.1) 55.8 (55.3–56.3) 52.6 (52.1–53.1) 64.0 (63.5–64.4) 61.8 (61.4–62.2) 51.0 (50.4–51.7)
13,946 (60.4) 4,489 (58.5) 2,341 (58.0) 1,116 (38.9) 468 (21.6) 2,065 (72.6) 1,144 (71.2)
9,391 (40.6) 3,986 (51.9) 2,825 (70.0) 1,384 (48.3) 1,029 (47.6) 1,446 (50.8) 799 (49.8)
Location of postoperative visits Overall, 53 % (95 % CI, 45–61 %) of postoperative visits for SSI were treated in the ED setting (Table 3). Similar to the variation in SSI rates by type of surgery, the proportion of ED visits for SSI also varied by surgery type, ranging from 36 % (95 % CI, 15–62 %) for trapeziometacarpal arthroplasty to 75 % (95 % CI, 28–97 %) for deQuervain surgery. Trapeziometacarpal arthroplasty and Dupuytren surgery were the only two hand procedures with more SSIs being treated in the inpatient setting than in the ED setting (50 % vs. 36 % and 56 % vs. 44 %, respectively).
Predictors of SSI After controlling for potential confounding effects in multivariable modeling (Table 4), we found that patients with government-funded insurance (Medicaid: OR 3.1, 95 % CI Table 2 Rates of postsurgical acute care visits for surgical site infections (SSIs) and for all causes within 14 days vs 30 days of hand surgery, 2010–2011 California
Type of surgery
21,515 (92.0) 7,273 (94.7) 3,910 (96.9) 2,728 (95.2) 2,034 (94.0) 2,677 (94.1) 1,543 (96.1)
1.7–5.4; Medicare: OR 2.4, 95 % CI 1.5–3.9) had higher odds of postoperative acute care visits for SSI than privately insured patients, and patients residing in rural areas had increased odds of acute care visits for SSI (OR 1.8, 95 % CI 1.02–3.0) compared with those in urban areas. We found no association of SSI with age, sex, diabetes, obesity, or tobacco use.
Discussion Preventing SSIs is integral to delivering safe, high-quality surgical care. As ambulatory surgery becomes increasingly common, there is growing interest in assessing, monitoring, and tracking SSIs that occur secondary to outpatient procedures [6]. A recent study showed that lapses in infection control (e.g. hand hygiene, environmental cleaning, equipment reprocessing) were common among Medicare-certified ambulatory surgical centres [12], suggesting that some SSIs in the
Index surgical procedures (n)
Number of postsurgical acute care visits for SSIs (rate/1,000 surgical procedures ) [95 % CI] Within 14 days
Visits for SSIs All surgery Carpal tunnel release Trigger finger release Wrist ganglion excision Cubital tunnel release Dupuytren surgery Basal joint arthroplasty De Quervain surgery Visit for all causes All surgery a
Within 30 days
44,305
76 (1.7) [1.4–2.1]
144 (3.3) [2.8–3.8]
23,109 7,680 4,036 2,867 2,163 2,844 1,606
37 (1.6) [1.1–2.2] 15 (2.0) [1.1–3.1] (1.0) [0.3–2.4]a (2.1) [0.9–4.3]a (2.3) [0.9–5.1]a (2.5) [1.1–4.8]a (1.2) [0.2–4.0]a
70 (3.0) [2.4–3.8] 25 (3.3) [2.2–4.7] (1.5) [0.6–3.0]a 16 (5.6) [3.3–8.8] (4.2) [2.1–7.6]a 14 (4.9) [2.8–8.0] (2.5) [0.8–5.9]a
44,305
1468 (33.1) [31.5–34.8]
2491 (56.2) [54.1–58.4]
Counts for cell sizes less than 11 have been suppressed to preserve the confidentiality of the data
International Orthopaedics (SICOT) Table 3 Distribution of postsurgical acute care visits for surgical site infections (SSIs) within 30 days of hand surgery in a hospital setting, 2010–2011 California Type of surgery
Index surgical procedures (n)
No. (%) [95 % CI] Inpatient hospitalization
Emergency department visit
Ambulatory surgery visit
All surgery
44,305
53 (36.8) [29.3–44.9]
76 (52.8) [44.6–60.8]
15 (10.4) [6.2–16.2]
Carpal tunnel release Trigger finger release Wrist ganglion excision Cubital tunnel release Dupuytren surgery Basal joint arthroplasty De Quervain surgery
23,109 7,680 4,036 2,867 2,163 2,844 1,606
22 (31.4) [21.5–42.9] (36.0) [19.5–55.5]a (33.3) [7.6–71.4]a (43.8) [22.2–67.4]a (55.5) [25.4–82.7]a (50.0) [25.9–74.1]a (25.0) [2.8–71.6]a
41 (58.6) [46.9–69.6] 13 (52.0) [33.1–70.5] (50.0) [16.7–83.3]a (43.8) [22.2–67.4]a (44.4) [17.3–74.6]a (35.7) [15.1–61.5]a (75.0) [28.3–97.2]a
(10.0) [4.5–18.6]a (12.0) [3.5–28.7]a (16.7) [1.8–55.8]a (12.5) [2.7–34.4]a (0.0) [0.0–23.7]a (14.3) [0.3–38.5]a (0.0) [0.0–44.5]a
a
Counts for cell sizes less than 11 have been suppressed to preserve the confidentiality of the data
outpatient surgery setting might be preventable through rigorous application of evidence-based guidelines. Most hand surgeries are performed on an outpatient basis and the burden of SSI in this setting remains largely unstudied. We therefore set out to assess the incidence of and factors associated with acute care visits for SSI among patients undergoing common hand surgery procedures. Our analysis should be interpreted cautiously in light of its limitations. First, because we used data originally intended for billing purposes, detailed clinical information was missing. In the absence of prospective care ascertainment and detailed clinical data, some SSIs may have represented delayed Table 4
outcome events secondary to other surgical procedures. However, this possibility is unlikely to have substantially affected our results, given that we excluded patients who had been seen in acute care in the 30 days prior to surgery. Second, as in all claims-based studies, coding misclassification and incompleteness can occur. Furthermore, coding accuracy could be influenced by financial incentives and fear or retribution [28, 29]. Third, patients with SSIs who made postoperative visits to physician offices were not captured. Fourth, although we used statewide data from one of the larger and more ethnically diverse states participating in the HCUP, our findings may not be generalizable to other regions in the
Characteristics of hand surgery patients with and without surgical site infection (SSI)
Variables
SSI (n=144)
No SSI (n=44161)
Crude OR (95 % CI)
Age- and sex-adjusted OR (95 % CI)
Fully-adjusted OR (95 % CI)
Age in years, mean±SD
55.3±14.7
57.2±14.5
0.99 (0.98 to 1.00)
0.99 (0.98 to 1.00)
0.98 (0.97 to 1.00)
50 (34.7) 86 (59.7) (5.6)a
14,699 (33.3) 25,483 (57.7) 3,979 (9.0)
Ref 0.99 (0.70–1.40) -
Ref 0.96 (0.68–1.37) -
Ref 0.94 (0.66–1.34) -
51 (35.4) 18 (12.5) 46 (31.9) 29 (19.4) 0 (0.0)
13,379 (30.3) 2,319 (5.3) 20,814 (47.1) 7,633 (16.6) 16 (0.1)
1.73 (1.15–2.60) 3.78 (2.18–6.60) Ref 1.74 (1.07–2.84) -
2.47 (1.50–4.06) 3.33 (1.90–5.86) Ref 1.66 (1.02–2.71) -
2.39 (1.45–3.93) 3.07 (1.74–5.43) Ref 1.67 (1.02–2.72) -
128 (88.9) 16 (11.1) (0.0)a 26 (18.1) 18 (12.5) 20 (13.9)
41,552 (94.1) 2,587 (5.9) 22 (0.1) 5,396 (12.2) 4,749 (10.8) 5,342 (12.1)
Ref 2.03 (1.18–3.47)
Ref 2.07 (1.21–3.55)
Ref 1.76 (1.02–3.04)
1.48 (0.96–2.29) 1.15 (0.70–1.89) 1.14 (0.71–1.83)
1.47 (0.95–2.27) 1.12 (0.68–1.84) 1.19 (0.74–1.93)
1.38 (0.89–2.15) 1.10 (0.66–1.84) 1.12 (0.68–1.82)
Sex, n (%) Male Female Missing Insurance status, n (%) Medicare Medicaid Private Other Missing Patient location, n (%) Urban Rural Missing Smoking, n (%) Obesity, n (%) Diabetes, n (%) a
Counts for cell sizes less than 11 have been suppressed to preserve the confidentiality of the data
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country. Fifth, we were not able to capture return to care provided in a federal facility or if the patient went to a different state [30]. Sixth, as in every observational study, there may be unmeasured factors that are related to the study outcome. However, our regression analysis adjusted for potential relevant predictors of infection identified in the literature. Finally, despite the large sample size, our study may be underpowered for some of the tested associations given the relative infrequency of SSI. Given the limited data available on this topic, our study provides important baseline information regarding current infection rates following outpatient hand surgery. The overall rate of acute care visits for SSI after one of several common hand surgeries was 0.33 %. Rates were lowest after ganglion cyst (0.15 %) and deQuervain surgery (0.25 %), and highest following cubital tunnel release (0.56 %) and trapeziometacarpal arthroplasty (0.49 %). The incidence of SSI after carpal tunnel release was 0.30 %, which was slightly lower than the rate (0.36 %) reported by Harness et al. [20]. This discrepancy in rates might be partly explained by the fact that Harness and colleagues did not exclude patients undergoing more than one hand surgery procedure simultaneously. Recently, Bykowski et al. [19] reviewed their institutional experience with carpal tunnel surgery and found a SSI rate of 0.24 %. Their infection rate could be lower than ours because their follow-up period was shorter (79 vs. 90 days), those patients with SSI seeking care at a different institution were not counted, and the examination of the surgical wound was performed by the original surgeon who might be less inclined to diagnose SSI [19]. We found that 0.20 % of patients undergoing trigger finger release developed SSIs that led to an acute care visit, which is considerably lower than the 2.0 % infection rate reported by Bruijnzeel et al. [31] in their ten-year institutional review of 1,598 trigger finger releases. The authors included less severe cases of infection (e.g. suture abscess, wound separation) that may be more commonly seen in the physician office than in acute care settings and are unlikely to result in serious adverse events. Although rates of postoperative acute care visits for SSIs following hand surgery were relatively low in our study, the absolute number of patients who develop these infections is substantial given how common hand surgery is, and because many SSIs entailed hospitalizations or additional ambulatory procedures. Our finding that Medicaid payer status conferred a threefold higher risk of SSI compared with private insurance patients is consistent with a recent study in spine surgery [32]. Although the risk was lower than for Medicaid, patients covered under Medicare were also more likely to develop SSI following hand surgery. In addition, we found that patients residing in rural areas had higher odds of postoperative visits for SSI than those living in urban areas. The observed influence of primary payer status and patient residence on development of SSI is likely multifactorial. Factors including
limited access to care, low health literacy, and a higher prevalence of risky behaviors (e.g. drug and alcohol abuse) may be at the heart of the poorer prognosis associated with underinsured patients and those living in rural areas [32–35]. It is also possible that these patients were referred to less experienced and less specialized surgeons, or that they were more likely to utilize the ED instead of going to the physician’s office for an infection [33, 36]. Reasons for the increased rates of postoperative acute care visits for SSI in these segments of the population merit further research. In our study, diabetes was not identified as an independent predictor of SSI leading to an acute care visit. It is possible that diabetic patients are at risk for infections seen in the physician office, but we cannot support or refute this with our data. It is also possible that because hand surgery is small and clean, diabetes does not increase the risk of postoperative infection. In fact, the effect of diabetes on the development of SSI after hand surgery is inconsistent in the literature [19, 20, 22, 37]. Although our sample is considerably larger than previous studies, it is possible that it is underpowered to detect an association, and this finding should be confirmed in other populations and data settings. In conclusion, this study provides evidence that the rates of acute care visits for SSI following ambulatory hand procedures are low but not negligible—particularly given how common hand surgery is, and the fact that many of these events are potentially preventable with evidence-based practices. We did not find modifiable risk factors (e.g. diabetes, tobacco use, obesity) for infection.
Appendix 1. Coding definitions for SSIs ICD-9-CM Diagnosis codes 686.0: Pyoderma 686.00: Pyoderma, unspecified 686.09: Other pyoderma 686.1: Pyogenic granuloma of skin and subcutaneous tissue 686.8: Other specified local infections of skin and subcutaneous tissue 998.5: Postoperative infection, not elsewhere classified 998.51: Infected postoperative seroma 998.59: Other postoperative infection 682.3: Cellulitis of arm 682.4: Cellulitis of hand 711.03: Pyogenic arthritis, forearm 711.63: Arthropathy associated with mycoses, forearm 711.64: Arthropathy associated with mycoses, hand 730.03: Acute osteomyelitis of forearm 730.04: Acute osteomyelitis of hand 730.23: Unspecified osteomyelitis of forearm
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730.24: Unspecified osteomyelitis of hand 730.93: Unspecified infection of bone, forearm 730.94: Unspecified infection of bone, hand
8.
9.
CPT Procedure codes 10.
10060: Incision and drainage of abscess (e.g., carbuncle, suppurative hidradenitis, cutaneous or subcutaneous abscess, cyst, furuncle, or paronychia); simple or single 10061: Incision and drainage of abscess (e.g., carbuncle, suppurative hidradenitis, cutaneous or subcutaneous abscess, cyst, furuncle, or paronychia); complicated or multiple 10180: Incision and drainage, complex, postoperative wound infection 11000: Debridement of extensive eczematous or infected skin; up to 10% of body surface 11001: Debridement of extensive eczematous or infected skin; each additional 10% of the body surface, or part thereof 20000: Incision of soft tissue abscess; superficial (musculoskeletal system) 20005: Incision of soft tissue abscess; deep or complicated (musculoskeletal system)
11. 12.
13.
14.
15.
ICD-9-CM Procedure codes
16.
86.04: Other incision with drainage of skin and subcutaneous tissue 86.22: Excisional debridement of wound, infection, or burn
17.
18.
References 19. 1.
2.
3. 4.
5. 6.
7.
Broex EC, van Asselt AD, Bruggeman CA, van Tiel FH (2009) Surgical site infections: how high are the costs? J Hosp Infect 72(3): 193–201. doi:10.1016/j.jhin.2009.03.020 de Lissovoy G, Fraeman K, Hutchins V, Murphy D, Song D, Vaughn BB (2009) Surgical site infection: incidence and impact on hospital utilization and treatment costs. Am J Infect Control 37(5):387–397. doi:10.1016/j.ajic.2008.12.010 Quinn A, Hill AD, Humphreys H (2009) Evolving issues in the prevention of surgical site infections. Surgeon 7(3):170–172 Whitehouse JD, Friedman ND, Kirkland KB, Richardson WJ, Sexton DJ (2002) The impact of surgical-site infections following orthopedic surgery at a community hospital and a university hospital: adverse quality of life, excess length of stay, and extra cost. Infect Control Hosp Epidemiol 23(4):183–189. doi:10.1086/ 502033 Shapiro S (1995) Microsurgical carpal tunnel release. Neurosurgery 37(1):66–70 Owens PL, Barrett ML, Raetzman S, Maggard-Gibbons M, Steiner CA (2014) Surgical site infections following ambulatory surgery procedures. JAMA 311(7):709–716. doi:10.1001/jama.2014.4 Milstein A (2009) Ending extra payment for Bnever events^–stronger incentives for patients’ safety. N Engl J Med 360(23):2388– 2390. doi:10.1056/NEJMp0809125
20.
21.
22.
23. 24.
25.
Rosenthal MB (2007) Nonpayment for performance? Medicare's new reimbursement rule. N Engl J Med 357(16):1573–1575. doi: 10.1056/NEJMp078184 Department of Health and Human Services (DHHS) National Action Plan to Prevent Healthcare-Associated Infections: Roadmap to Elimination. DHHS website. http://www.hhs.gov/ ash/initiatives/hai/infection.html. Accessed 3 November 2014 Department of Health and Human Services (DHHS) National Action Plan to Prevent Healthcare-Associated Infections: Road Map to Elimination: Ambulatory Surgical Centers. DHHS website. http://www.hhs.gov/ash/initiatives/hai/ambulatory_surgical_ centers.html. 3 November 2014 Cullen KA, Hall MJ, Golosinskiy A (2009) Ambulatory surgery in the United States, 2006. Natl Health Stat Report 11:1–25 Schaefer MK, Jhung M, Dahl M, Schillie S, Simpson C, Llata E, Link-Gelles R, Sinkowitz-Cochran R, Patel P, Bolyard E, Sehulster L, Srinivasan A, Perz JF (2010) Infection control assessment of ambulatory surgical centers. JAMA 303(22):2273–2279. doi:10. 1001/jama.2010.744 Bachoura A, Guitton TG, Smith RM, Vrahas MS, Zurakowski D, Ring D (2011) Infirmity and injury complexity are risk factors for surgical-site infection after operative fracture care. Clin Orthop Relat Res 469(9):2621–2630. doi:10.1007/s11999-010-1737-2 Gradl G, de Witte PB, Evans BT, Hornicek F, Raskin K, Ring D (2014) Surgical site infection in orthopaedic oncology. J Bone Joint Surg Am 96(3):223–230. doi:10.2106/JBJS.L.01514 Nota SP, Braun Y, Ring D, Schwab JH (2015) Incidence of surgical site infection after spine surgery: what Is the impact of the definition of infection? Clin Orthop Relat Res 473(5):1612–1619. doi:10. 1007/s11999-014-3933-y Pryor KO, Fahey TJ 3rd, Lien CA, Goldstein PA (2004) Surgical site infection and the routine use of perioperative hyperoxia in a general surgical population: a randomized controlled trial. JAMA 291(1):79–87. doi:10.1001/jama.291.1.79 Takeishi K, Yamashita Y, Tsujita E, Maeda T, Tsutsui S, Matsuda H, Shirabe K, Ishida T, Maehara Y (2014) Risk factors for organ/space surgical site infection after hepatectomy for hepatocellular carcinoma. Am Surg 80(11):1173–1175 Rasouli MR, Restrepo C, Maltenfort MG, Purtill JJ, Parvizi J (2014) Risk factors for surgical site infection following total joint arthroplasty. J Bone Joint Surg Am 96(18):e158. doi:10.2106/JBJS.M.01363 Bykowski MR, Sivak WN, Cray J, Buterbaugh G, Imbriglia JE, Lee WP (2011) Assessing the impact of antibiotic prophylaxis in outpatient elective hand surgery: a single-center, retrospective review of 8,850 cases. J Hand Surg [Am] 36(11):1741–1747. doi:10.1016/ j.jhsa.2011.08.005 Harness NG, Inacio MC, Pfeil FF, Paxton LW (2010) Rate of infection after carpal tunnel release surgery and effect of antibiotic prophylaxis. J Hand Surg [Am] 35(2):189–196. doi:10.1016/j.jhsa. 2009.11.012 Hashemi K, Blakeley CJ (2004) Wound infections in day-case hand surgery: a prospective study. Ann R Coll Surg Engl 86(6):449–450. doi:10.1308/147870804687 Zwiebel S, Becker D (2014) Risk of postoperative infection following carpal tunnel release in patients with diabetes mellitus: a review of 658 surgeries. Plast Reconstr Surg 134(4 Suppl 1):37. doi:10. 1097/01.prs.0000455366.67857.24 Grayson MJ, Saldana MJ (1987) Toxic shock syndrome complicating surgery of the hand. J Hand Surg [Am] 12(6):1082–1084 Rigopoulos N, Dailiana ZH, Varitimidis S, Hantes M, Bargiotas K, Malizos KN (2008) Compartmental infections of the hand. Scand J Plast Reconstr Surg Hand Surg 42(1):38–42. doi:10.1080/ 02844310701553967 Smith PA, Hankin FM, Louis DS (1986) Postoperative toxic shock syndrome after reconstructive surgery of the hand. J Hand Surg [Am] 11(3):399–402
International Orthopaedics (SICOT) 26.
Agency for Healthcare Research and Quality (AHRQ) Healthcare Cost and Utilization Project (HCUP) Databases. AHRQ website. http://www.hcup-us.ahrq.gov/databases.jsp. Accessed 1 November 2014. 27. Martin CT, Pugely AJ, Gao Y, Ilgenfritz RM, Weinstein SL (2014) Incidence and risk factors for early wound complications after spinal arthrodesis in children: analysis of 30-day follow-up data from the ACS-NSQIP. Spine (Phila Pa 1976) 39(18):1463–1470. doi:10. 1097/BRS.0000000000000446 28. Hayward RA, Hofer TP (2001) Estimating hospital deaths due to medical errors: preventability is in the eye of the reviewer. JAMA 286(4):415–420 29. Simborg DW (1981) DRG creep: a new hospital-acquired disease. N Engl J Med 304(26):1602–1604. doi:10.1056/ NEJM198106253042611 30. Curtin CM, Hernandez-Boussard T (2014) Readmissions after treatment of distal radius fractures. J Hand Surg [Am] 39(10): 1926–1932. doi:10.1016/j.jhsa.2014.07.041 31. Bruijnzeel H, Neuhaus V, Fostvedt S, Jupiter JB, Mudgal CS, Ring DC (2012) Adverse events of open A1 pulley release for idiopathic trigger finger. J Hand Surg [Am] 37(8):1650–1656. doi:10.1016/j. jhsa.2012.05.014
32.
33.
34.
35.
36.
37.
Manoso MW, Cizik AM, Bransford RJ, Bellabarba C, Chapman J, Lee MJ (2014) Medicaid status is associated with higher surgical site infection rates after spine surgery. Spine (Phila Pa 1976) 39(20): 1707–1713. doi:10.1097/BRS.0000000000000496 LaPar DJ, Bhamidipati CM, Mery CM, Stukenborg GJ, Jones DR, Schirmer BD, Kron IL, Ailawadi G (2010) Primary payer status affects mortality for major surgical operations. Ann Surg 252(3): 544–550. doi:10.1097/SLA.0b013e3181e8fd75, discussion 550-541 Menendez ME, Ring D (2014) Minorities are less likely to receive autologous blood transfusion for major elective orthopaedic surgery. Clin Orthop Relat Res 472(11):3559–3566. doi:10.1007/ s11999-014-3793-5 Menendez ME, van Dijk CN, Ring D (2014) Who leaves the hospital against medical advice in the orthopaedic setting? Clin Orthop Relat Res 473(3):1140–1149. doi:10.1007/s11999-014-3924-z Taubman SL, Allen HL, Wright BJ, Baicker K, Finkelstein AN (2014) Medicaid increases emergency-department use: evidence from Oregon's Health Insurance Experiment. Science 343(6168): 263–268. doi:10.1126/science.1246183 Mondelli M, Padua L, Reale F, Signorini AM, Romano C (2004) Outcome of surgical release among diabetics with carpal tunnel syndrome. Arch Phys Med Rehabil 85(1):7–13
ORIGINAL PAPER
Surgical site infection in hand surgery Mariano E. Menendez 1 & Na Lu 2,3 & Sebastian Unizony 3 & Hyon K. Choi 2,3 & David Ring 1
Received: 19 March 2015 / Accepted: 21 April 2015 # SICOT aisbl 2015
Abstract Purpose As ambulatory surgery becomes increasingly common, there is growing interest in assessing, monitoring, and tracking complications that occur secondary to outpatient procedures. We sought to determine the rates of 14- and 30-day acute care visits for surgical site infection after outpatient hand surgery, and to identify associated factors. Methods Using the California State Ambulatory Surgery database for 2010 and 2011, we identified 44,305 patients undergoing common outpatient hand surgery procedures. Cases were linked to the State Emergency Department and the State Inpatient databases for postoperative acute care visits (e.g. hospitalizations, emergency department or ambulatory surgical visits) related to surgical site infection. Results Postoperative acute care visits for surgical site infection occurred in 1.7 per 1,000 hand surgery procedures (0.17 %) at 14 days, and 3.3 per 1,000 (0.33 %) at 30 days. Thirty-day infection rates were lowest after ganglion cyst (0.15 %) and deQuervain surgery (0.25 %), and highest following cubital tunnel release (0.56 %) and trapeziometacarpal arthroplasty (0.49 %). Fifty-three percent of postoperative visits were treated in the emergency department setting, Level of evidence: Level III, Prognostic study * David Ring [email protected] 1
Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Yawkey Center, Suite 2100, Boston, MA 02114, USA
2
Clinical Epidemiology Unit, Boston University School of Medicine, Boston, MA, USA
3
Rheumatology Allergy and Immunology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
37 % in the inpatient setting, and 10 % required an additional outpatient surgical procedure. Patients with governmentfunded insurance—Medicaid in particular—and those residing in rural areas had higher odds of postoperative acute care visits for surgical site infection. Diabetes, obesity, and tobacco use were not associated with increased risk for infection leading to an acute care visit. Conclusion The rates of postoperative acute care visits for surgical site infection after ambulatory hand procedures are low but not negligible—particularly given how common hand surgery is, and the fact that many of these events entail hospitalizations or additional ambulatory procedures. Reasons for the increased risk of acute care visits for infection among publicly insured and rural patients merit additional research. Keywords Surgical site infection . Hand surgery . Complication . Patient safety . Quality improvement
Introduction Surgical site infections (SSIs) are associated with substantial morbidity and resource utilization, and inevitably result in prolonged recovery and lower quality of life [1–5]. With increasing emphasis placed on improving patient safety and quality of care while constraining costs, reducing SSIs has become a priority for both policymakers and clinical leaders [6]. In 2008, to promote and accelerate strategies to prevent healthcare-associated infections, the Centers for Medicare and Medicaid Services (CMS) began denying reimbursement for SSIs after selected inpatient surgeries [7, 8]. In that same year, the US Department of Health and Human Services established the National Action Plan to Prevent Healthcare-Associated Infections [9]. This plan initially focused on preventing SSIs
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after inpatient surgery but subsequently broadened to encompass outpatient surgery [10]. Although nearly two-thirds of all surgeries in the United States are now being performed outpatient [11, 12], research on SSIs is largely confined to the inpatient setting [13–18]. A recent population-based study by Owens et al. [6] emphasized that SSIs are also common after ambulatory surgery. Hand surgery is common, but there is limited research about the incidence and correlates of SSI in this setting [19–22]. The available data are mainly derived from single institutions, focus exclusively on one procedure (e.g. carpal tunnel release), and do not contain enough infections to conduct meaningful statistical analysis [19–22]. Given that even seemingly trivial SSIs following hand surgery can have important clinical and economic consequences [4, 23–25], a better understanding of their incidence and associated factors might prove useful for better allocation of resources and implementation of preventive strategies. To address this gap in knowledge, we calculated population estimates of 14- and 30-day acute care visit rates (e.g. hospitalizations, emergency department or ambulatory surgical visits) for SSI following common outpatient hand surgery procedures. In addition, we identified potential predictors of SSI after hand surgery.
ambulatory surgery—by linking the initial encounter data to the corresponding State Inpatient Database (SID) and State Emergency Department Database (SEDD). This study was exempt from review by our Institutional Review Board because the data are publicly available and contain no personal identifiable information. Study sample We initially considered all ambulatory surgery records for patients undergoing common hand procedures between 2010 and 2011. Using CPT codes, combined with ICD-9-CM diagnosis codes for procedures with less-specific CPT codes, we selected seven hand surgeries: carpal tunnel release (CPT code 64721), trigger finger release (CPT code 26055 and ICD-9CM code 727.03), wrist ganglion excision (CPT code 25111), cubital tunnel release (CPT code 64718 and ICD-9 code 354.2), Dupuytren surgery (CPT code 26123 and ICD-9-CM code 728.6), de Quervain surgery (CPT code 25000 and ICD9-CM code 727.04), and trapeziometacarpal arthroplasty (CPT codes 25445 or 25447). Patient demographic variables consisted of age, sex, primary health insurance, and residential area. Outcome measures
Materials and methods Data source and study design Encounter data for this retrospective cohort study were abstracted from the California State Ambulatory Surgery Database (SASD) for 2010 and 2011 [26]. This dataset is part of the Healthcare Cost and Utilization Project (HCUP), an initiative operated by the Agency for Healthcare Research and Quality. The California SASD collects all-payer encounter-level information on surgical procedures performed in ambulatory settings, with no overnight inpatient stay. These encompass surgical suites within a hospital as well as hospitalaffiliated and freestanding surgical facilities. Procedures performed in physician offices are not included in this dataset [6]. The SASD utilizes the Current Procedural Terminology (CPT) codes to standardize the reporting of up to 21 surgical procedures, and the International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] codes for the reporting of up to 25 medical diagnoses. We chose California because it is one of the larger and more ethnically diverse states participating in the HCUP, and is currently the state with the second greatest number of ambulatory surgery facilities [26]. Through the use of unique encrypted patient-level identifiers, we tracked patients over time and across different hospital settings—inpatient, emergency department, and
The primary outcome of interest was the rate of postsurgical acute care visits for surgical site infection (SSI) following each of the selected hand procedures. Postoperative encounters for SSIs were identified using a validated algorithm that employed ICD-9-CM diagnosis or procedure codes and CPT codes (Appendix 1) [6]. The denominator was the number of hand surgery procedures, and the numerator was the number of those procedures that resulted in at least one subsequent emergency department (ED) visit, ambulatory surgery visit, or inpatient stay for a SSI within 14 or 30 days [6]. Patients with more than one subsequent visit during this time period were counted only once in the numerator. We included ED visits because, unlike other musculoskeletal procedures such as total joint arthroplasty or spinal laminectomy, we suspected that many SSIs after hand surgery would not require an inpatient admission or an additional outpatient surgical procedure. Patients with SSIs who made postsurgical visits to physician offices were not captured. The rates were reported per 1,000 surgical procedures. We also computed rates of postoperative visits for all causes (including SSI) in order to evaluate the relative importance of SSI as a reason for postsurgical visits. Records for hand surgery procedures performed in January 2010 or December 2011 were excluded to allow a window of 30 days before and after surgery to assess other hospital visits (n=4,737). In order to select a homogenous cohort of adult patients at low surgical risk, we excluded patients aged less than 18 years old (n=2,148), patients undergoing more than
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one procedure on the same visit (n=3,232), patients with a non-routine discharge disposition (n=57), and those who had been seen in acute care in the 30 days prior to surgery (n=2,042). We retained 44,305 records for hand surgery procedures (Fig. 1). Statistical analysis We assessed patient demographic characteristics associated with each hand surgery. Overall and procedure-specific observed rates of postoperative visits for SSIs and all causes were determined at 14 and 30 days. Assuming a binomial distribution, we used Jeffrey intervals to calculate 95 % CIs [6]. Multivariable logistic regression modeling was used to identify factors associated with development of SSI after hand surgery. Besides sociodemographic characteristics, we included diabetes and tobacco use in our model, as they have been previously suggested as predictors of SSI in the hand surgery setting [19]. We also considered obesity because it has been associated with higher risk for SSI following other orthopaedic procedures [27, 15]. All covariates were entered into the model simultaneously, without further selection. Besides reporting fully adjusted odds ratios (OR) with 95 % confidence intervals (CI), we presented crude (unadjusted) OR and age- and sex-adjusted OR. Data management and statistical analyses were performed using SAS version 9.3 (SAS Institute, Cary, NC).
Results Patient characteristics The mean age of patients undergoing hand surgery ranged from 53 years (cubital tunnel release) to 64 years Fig. 1 Hand surgery procedures meeting study criteria
(Dupuytren surgery) (Table 1). Trapeziometacarpal arthroplasty (73 %) and deQuervain surgery (71 %) were more likely to be performed on women; in contrast, surgery for Dupuytren contracture (22 %) and cubital tunnel release (39 %) were less likely to be performed on women. More than 90 % of each selected surgery was performed on patients from metropolitan areas, varying from a low of 92 % for carpal tunnel release to a high of 96 % for removal of a ganglion cyst. Seventy percent of ganglion cyst removals were billed to private insurance, compared to only 41 % of carpal tunnel surgeries. Rate of postoperative visits for SSI The overall rate of postoperative visits for SSI within 14 days was 1.7 (95 % CI, 1.4–2.1) per 1,000 hand surgery procedures (Table 2). The 14-day rates of postoperative visits for SSI varied by type of surgery, ranging from 1.0 (95 % CI, 0.30-2.4) per 1000 ganglion cyst removals to 2.5 (95 % CI, 1.1-4.8) per 1000 trapeziometacarpal arthroplasties. The overall rate of all-cause postoperative acute care visits within 14 days was 33 (95 % CI, 32-35) per 1000 hand surgeries, thus indicating that SSIs were the cause of 5.2 % of all postoperative visits. The overall rate of postoperative visits for SSI increased from 1.7 (95 % CI, 1.4–2.1) to 3.3 (95 % CI, 2.8–3.8) per 1,000 surgical procedures when the time frame was extended to 30 days. The 30-day rates of postoperative visits for SSI also varied by type of surgery and ranged from 1.5 (95 % CI, 0.60–3.0) per 1,000 ganglion cyst removals to 5.6 (95 % CI, 3.3–8.8) per 1,000 cubital tunnel releases. The overall rate of 30-day acute care visits for all causes was 56 (95 % CI, 54–58) per 1,000 procedures, therefore implying that SSIs were responsible for 5.8 % of all postoperative visits.
International Orthopaedics (SICOT) Table 1
Characteristics of patients undergoing hand surgery, 2010–2011 California
Type of surgery
Index Surgical Procedures, No. Age, mean (95 % CI), years Number (%) Women
Metropolitan residence Primary expected payer: private
All surgery
44,305
57.2 (57.1–57.4)
25,569 (57.7) 41,680 (94.1)
20,860 (46.3)
Carpal tunnel release Trigger finger release Wrist ganglion excision Cubital tunnel release Dupuytren surgery Basal joint arthroplasty De Quervain surgery
23,109 7,680 4,036 2,867 2,163 2,844 1,606
58.3 (58.1–58.5) 59.9 (59.6–60.1) 55.8 (55.3–56.3) 52.6 (52.1–53.1) 64.0 (63.5–64.4) 61.8 (61.4–62.2) 51.0 (50.4–51.7)
13,946 (60.4) 4,489 (58.5) 2,341 (58.0) 1,116 (38.9) 468 (21.6) 2,065 (72.6) 1,144 (71.2)
9,391 (40.6) 3,986 (51.9) 2,825 (70.0) 1,384 (48.3) 1,029 (47.6) 1,446 (50.8) 799 (49.8)
Location of postoperative visits Overall, 53 % (95 % CI, 45–61 %) of postoperative visits for SSI were treated in the ED setting (Table 3). Similar to the variation in SSI rates by type of surgery, the proportion of ED visits for SSI also varied by surgery type, ranging from 36 % (95 % CI, 15–62 %) for trapeziometacarpal arthroplasty to 75 % (95 % CI, 28–97 %) for deQuervain surgery. Trapeziometacarpal arthroplasty and Dupuytren surgery were the only two hand procedures with more SSIs being treated in the inpatient setting than in the ED setting (50 % vs. 36 % and 56 % vs. 44 %, respectively).
Predictors of SSI After controlling for potential confounding effects in multivariable modeling (Table 4), we found that patients with government-funded insurance (Medicaid: OR 3.1, 95 % CI Table 2 Rates of postsurgical acute care visits for surgical site infections (SSIs) and for all causes within 14 days vs 30 days of hand surgery, 2010–2011 California
Type of surgery
21,515 (92.0) 7,273 (94.7) 3,910 (96.9) 2,728 (95.2) 2,034 (94.0) 2,677 (94.1) 1,543 (96.1)
1.7–5.4; Medicare: OR 2.4, 95 % CI 1.5–3.9) had higher odds of postoperative acute care visits for SSI than privately insured patients, and patients residing in rural areas had increased odds of acute care visits for SSI (OR 1.8, 95 % CI 1.02–3.0) compared with those in urban areas. We found no association of SSI with age, sex, diabetes, obesity, or tobacco use.
Discussion Preventing SSIs is integral to delivering safe, high-quality surgical care. As ambulatory surgery becomes increasingly common, there is growing interest in assessing, monitoring, and tracking SSIs that occur secondary to outpatient procedures [6]. A recent study showed that lapses in infection control (e.g. hand hygiene, environmental cleaning, equipment reprocessing) were common among Medicare-certified ambulatory surgical centres [12], suggesting that some SSIs in the
Index surgical procedures (n)
Number of postsurgical acute care visits for SSIs (rate/1,000 surgical procedures ) [95 % CI] Within 14 days
Visits for SSIs All surgery Carpal tunnel release Trigger finger release Wrist ganglion excision Cubital tunnel release Dupuytren surgery Basal joint arthroplasty De Quervain surgery Visit for all causes All surgery a
Within 30 days
44,305
76 (1.7) [1.4–2.1]
144 (3.3) [2.8–3.8]
23,109 7,680 4,036 2,867 2,163 2,844 1,606
37 (1.6) [1.1–2.2] 15 (2.0) [1.1–3.1] (1.0) [0.3–2.4]a (2.1) [0.9–4.3]a (2.3) [0.9–5.1]a (2.5) [1.1–4.8]a (1.2) [0.2–4.0]a
70 (3.0) [2.4–3.8] 25 (3.3) [2.2–4.7] (1.5) [0.6–3.0]a 16 (5.6) [3.3–8.8] (4.2) [2.1–7.6]a 14 (4.9) [2.8–8.0] (2.5) [0.8–5.9]a
44,305
1468 (33.1) [31.5–34.8]
2491 (56.2) [54.1–58.4]
Counts for cell sizes less than 11 have been suppressed to preserve the confidentiality of the data
International Orthopaedics (SICOT) Table 3 Distribution of postsurgical acute care visits for surgical site infections (SSIs) within 30 days of hand surgery in a hospital setting, 2010–2011 California Type of surgery
Index surgical procedures (n)
No. (%) [95 % CI] Inpatient hospitalization
Emergency department visit
Ambulatory surgery visit
All surgery
44,305
53 (36.8) [29.3–44.9]
76 (52.8) [44.6–60.8]
15 (10.4) [6.2–16.2]
Carpal tunnel release Trigger finger release Wrist ganglion excision Cubital tunnel release Dupuytren surgery Basal joint arthroplasty De Quervain surgery
23,109 7,680 4,036 2,867 2,163 2,844 1,606
22 (31.4) [21.5–42.9] (36.0) [19.5–55.5]a (33.3) [7.6–71.4]a (43.8) [22.2–67.4]a (55.5) [25.4–82.7]a (50.0) [25.9–74.1]a (25.0) [2.8–71.6]a
41 (58.6) [46.9–69.6] 13 (52.0) [33.1–70.5] (50.0) [16.7–83.3]a (43.8) [22.2–67.4]a (44.4) [17.3–74.6]a (35.7) [15.1–61.5]a (75.0) [28.3–97.2]a
(10.0) [4.5–18.6]a (12.0) [3.5–28.7]a (16.7) [1.8–55.8]a (12.5) [2.7–34.4]a (0.0) [0.0–23.7]a (14.3) [0.3–38.5]a (0.0) [0.0–44.5]a
a
Counts for cell sizes less than 11 have been suppressed to preserve the confidentiality of the data
outpatient surgery setting might be preventable through rigorous application of evidence-based guidelines. Most hand surgeries are performed on an outpatient basis and the burden of SSI in this setting remains largely unstudied. We therefore set out to assess the incidence of and factors associated with acute care visits for SSI among patients undergoing common hand surgery procedures. Our analysis should be interpreted cautiously in light of its limitations. First, because we used data originally intended for billing purposes, detailed clinical information was missing. In the absence of prospective care ascertainment and detailed clinical data, some SSIs may have represented delayed Table 4
outcome events secondary to other surgical procedures. However, this possibility is unlikely to have substantially affected our results, given that we excluded patients who had been seen in acute care in the 30 days prior to surgery. Second, as in all claims-based studies, coding misclassification and incompleteness can occur. Furthermore, coding accuracy could be influenced by financial incentives and fear or retribution [28, 29]. Third, patients with SSIs who made postoperative visits to physician offices were not captured. Fourth, although we used statewide data from one of the larger and more ethnically diverse states participating in the HCUP, our findings may not be generalizable to other regions in the
Characteristics of hand surgery patients with and without surgical site infection (SSI)
Variables
SSI (n=144)
No SSI (n=44161)
Crude OR (95 % CI)
Age- and sex-adjusted OR (95 % CI)
Fully-adjusted OR (95 % CI)
Age in years, mean±SD
55.3±14.7
57.2±14.5
0.99 (0.98 to 1.00)
0.99 (0.98 to 1.00)
0.98 (0.97 to 1.00)
50 (34.7) 86 (59.7) (5.6)a
14,699 (33.3) 25,483 (57.7) 3,979 (9.0)
Ref 0.99 (0.70–1.40) -
Ref 0.96 (0.68–1.37) -
Ref 0.94 (0.66–1.34) -
51 (35.4) 18 (12.5) 46 (31.9) 29 (19.4) 0 (0.0)
13,379 (30.3) 2,319 (5.3) 20,814 (47.1) 7,633 (16.6) 16 (0.1)
1.73 (1.15–2.60) 3.78 (2.18–6.60) Ref 1.74 (1.07–2.84) -
2.47 (1.50–4.06) 3.33 (1.90–5.86) Ref 1.66 (1.02–2.71) -
2.39 (1.45–3.93) 3.07 (1.74–5.43) Ref 1.67 (1.02–2.72) -
128 (88.9) 16 (11.1) (0.0)a 26 (18.1) 18 (12.5) 20 (13.9)
41,552 (94.1) 2,587 (5.9) 22 (0.1) 5,396 (12.2) 4,749 (10.8) 5,342 (12.1)
Ref 2.03 (1.18–3.47)
Ref 2.07 (1.21–3.55)
Ref 1.76 (1.02–3.04)
1.48 (0.96–2.29) 1.15 (0.70–1.89) 1.14 (0.71–1.83)
1.47 (0.95–2.27) 1.12 (0.68–1.84) 1.19 (0.74–1.93)
1.38 (0.89–2.15) 1.10 (0.66–1.84) 1.12 (0.68–1.82)
Sex, n (%) Male Female Missing Insurance status, n (%) Medicare Medicaid Private Other Missing Patient location, n (%) Urban Rural Missing Smoking, n (%) Obesity, n (%) Diabetes, n (%) a
Counts for cell sizes less than 11 have been suppressed to preserve the confidentiality of the data
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country. Fifth, we were not able to capture return to care provided in a federal facility or if the patient went to a different state [30]. Sixth, as in every observational study, there may be unmeasured factors that are related to the study outcome. However, our regression analysis adjusted for potential relevant predictors of infection identified in the literature. Finally, despite the large sample size, our study may be underpowered for some of the tested associations given the relative infrequency of SSI. Given the limited data available on this topic, our study provides important baseline information regarding current infection rates following outpatient hand surgery. The overall rate of acute care visits for SSI after one of several common hand surgeries was 0.33 %. Rates were lowest after ganglion cyst (0.15 %) and deQuervain surgery (0.25 %), and highest following cubital tunnel release (0.56 %) and trapeziometacarpal arthroplasty (0.49 %). The incidence of SSI after carpal tunnel release was 0.30 %, which was slightly lower than the rate (0.36 %) reported by Harness et al. [20]. This discrepancy in rates might be partly explained by the fact that Harness and colleagues did not exclude patients undergoing more than one hand surgery procedure simultaneously. Recently, Bykowski et al. [19] reviewed their institutional experience with carpal tunnel surgery and found a SSI rate of 0.24 %. Their infection rate could be lower than ours because their follow-up period was shorter (79 vs. 90 days), those patients with SSI seeking care at a different institution were not counted, and the examination of the surgical wound was performed by the original surgeon who might be less inclined to diagnose SSI [19]. We found that 0.20 % of patients undergoing trigger finger release developed SSIs that led to an acute care visit, which is considerably lower than the 2.0 % infection rate reported by Bruijnzeel et al. [31] in their ten-year institutional review of 1,598 trigger finger releases. The authors included less severe cases of infection (e.g. suture abscess, wound separation) that may be more commonly seen in the physician office than in acute care settings and are unlikely to result in serious adverse events. Although rates of postoperative acute care visits for SSIs following hand surgery were relatively low in our study, the absolute number of patients who develop these infections is substantial given how common hand surgery is, and because many SSIs entailed hospitalizations or additional ambulatory procedures. Our finding that Medicaid payer status conferred a threefold higher risk of SSI compared with private insurance patients is consistent with a recent study in spine surgery [32]. Although the risk was lower than for Medicaid, patients covered under Medicare were also more likely to develop SSI following hand surgery. In addition, we found that patients residing in rural areas had higher odds of postoperative visits for SSI than those living in urban areas. The observed influence of primary payer status and patient residence on development of SSI is likely multifactorial. Factors including
limited access to care, low health literacy, and a higher prevalence of risky behaviors (e.g. drug and alcohol abuse) may be at the heart of the poorer prognosis associated with underinsured patients and those living in rural areas [32–35]. It is also possible that these patients were referred to less experienced and less specialized surgeons, or that they were more likely to utilize the ED instead of going to the physician’s office for an infection [33, 36]. Reasons for the increased rates of postoperative acute care visits for SSI in these segments of the population merit further research. In our study, diabetes was not identified as an independent predictor of SSI leading to an acute care visit. It is possible that diabetic patients are at risk for infections seen in the physician office, but we cannot support or refute this with our data. It is also possible that because hand surgery is small and clean, diabetes does not increase the risk of postoperative infection. In fact, the effect of diabetes on the development of SSI after hand surgery is inconsistent in the literature [19, 20, 22, 37]. Although our sample is considerably larger than previous studies, it is possible that it is underpowered to detect an association, and this finding should be confirmed in other populations and data settings. In conclusion, this study provides evidence that the rates of acute care visits for SSI following ambulatory hand procedures are low but not negligible—particularly given how common hand surgery is, and the fact that many of these events are potentially preventable with evidence-based practices. We did not find modifiable risk factors (e.g. diabetes, tobacco use, obesity) for infection.
Appendix 1. Coding definitions for SSIs ICD-9-CM Diagnosis codes 686.0: Pyoderma 686.00: Pyoderma, unspecified 686.09: Other pyoderma 686.1: Pyogenic granuloma of skin and subcutaneous tissue 686.8: Other specified local infections of skin and subcutaneous tissue 998.5: Postoperative infection, not elsewhere classified 998.51: Infected postoperative seroma 998.59: Other postoperative infection 682.3: Cellulitis of arm 682.4: Cellulitis of hand 711.03: Pyogenic arthritis, forearm 711.63: Arthropathy associated with mycoses, forearm 711.64: Arthropathy associated with mycoses, hand 730.03: Acute osteomyelitis of forearm 730.04: Acute osteomyelitis of hand 730.23: Unspecified osteomyelitis of forearm
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730.24: Unspecified osteomyelitis of hand 730.93: Unspecified infection of bone, forearm 730.94: Unspecified infection of bone, hand
8.
9.
CPT Procedure codes 10.
10060: Incision and drainage of abscess (e.g., carbuncle, suppurative hidradenitis, cutaneous or subcutaneous abscess, cyst, furuncle, or paronychia); simple or single 10061: Incision and drainage of abscess (e.g., carbuncle, suppurative hidradenitis, cutaneous or subcutaneous abscess, cyst, furuncle, or paronychia); complicated or multiple 10180: Incision and drainage, complex, postoperative wound infection 11000: Debridement of extensive eczematous or infected skin; up to 10% of body surface 11001: Debridement of extensive eczematous or infected skin; each additional 10% of the body surface, or part thereof 20000: Incision of soft tissue abscess; superficial (musculoskeletal system) 20005: Incision of soft tissue abscess; deep or complicated (musculoskeletal system)
11. 12.
13.
14.
15.
ICD-9-CM Procedure codes
16.
86.04: Other incision with drainage of skin and subcutaneous tissue 86.22: Excisional debridement of wound, infection, or burn
17.
18.
References 19. 1.
2.
3. 4.
5. 6.
7.
Broex EC, van Asselt AD, Bruggeman CA, van Tiel FH (2009) Surgical site infections: how high are the costs? J Hosp Infect 72(3): 193–201. doi:10.1016/j.jhin.2009.03.020 de Lissovoy G, Fraeman K, Hutchins V, Murphy D, Song D, Vaughn BB (2009) Surgical site infection: incidence and impact on hospital utilization and treatment costs. Am J Infect Control 37(5):387–397. doi:10.1016/j.ajic.2008.12.010 Quinn A, Hill AD, Humphreys H (2009) Evolving issues in the prevention of surgical site infections. Surgeon 7(3):170–172 Whitehouse JD, Friedman ND, Kirkland KB, Richardson WJ, Sexton DJ (2002) The impact of surgical-site infections following orthopedic surgery at a community hospital and a university hospital: adverse quality of life, excess length of stay, and extra cost. Infect Control Hosp Epidemiol 23(4):183–189. doi:10.1086/ 502033 Shapiro S (1995) Microsurgical carpal tunnel release. Neurosurgery 37(1):66–70 Owens PL, Barrett ML, Raetzman S, Maggard-Gibbons M, Steiner CA (2014) Surgical site infections following ambulatory surgery procedures. JAMA 311(7):709–716. doi:10.1001/jama.2014.4 Milstein A (2009) Ending extra payment for Bnever events^–stronger incentives for patients’ safety. N Engl J Med 360(23):2388– 2390. doi:10.1056/NEJMp0809125
20.
21.
22.
23. 24.
25.
Rosenthal MB (2007) Nonpayment for performance? Medicare's new reimbursement rule. N Engl J Med 357(16):1573–1575. doi: 10.1056/NEJMp078184 Department of Health and Human Services (DHHS) National Action Plan to Prevent Healthcare-Associated Infections: Roadmap to Elimination. DHHS website. http://www.hhs.gov/ ash/initiatives/hai/infection.html. Accessed 3 November 2014 Department of Health and Human Services (DHHS) National Action Plan to Prevent Healthcare-Associated Infections: Road Map to Elimination: Ambulatory Surgical Centers. DHHS website. http://www.hhs.gov/ash/initiatives/hai/ambulatory_surgical_ centers.html. 3 November 2014 Cullen KA, Hall MJ, Golosinskiy A (2009) Ambulatory surgery in the United States, 2006. Natl Health Stat Report 11:1–25 Schaefer MK, Jhung M, Dahl M, Schillie S, Simpson C, Llata E, Link-Gelles R, Sinkowitz-Cochran R, Patel P, Bolyard E, Sehulster L, Srinivasan A, Perz JF (2010) Infection control assessment of ambulatory surgical centers. JAMA 303(22):2273–2279. doi:10. 1001/jama.2010.744 Bachoura A, Guitton TG, Smith RM, Vrahas MS, Zurakowski D, Ring D (2011) Infirmity and injury complexity are risk factors for surgical-site infection after operative fracture care. Clin Orthop Relat Res 469(9):2621–2630. doi:10.1007/s11999-010-1737-2 Gradl G, de Witte PB, Evans BT, Hornicek F, Raskin K, Ring D (2014) Surgical site infection in orthopaedic oncology. J Bone Joint Surg Am 96(3):223–230. doi:10.2106/JBJS.L.01514 Nota SP, Braun Y, Ring D, Schwab JH (2015) Incidence of surgical site infection after spine surgery: what Is the impact of the definition of infection? Clin Orthop Relat Res 473(5):1612–1619. doi:10. 1007/s11999-014-3933-y Pryor KO, Fahey TJ 3rd, Lien CA, Goldstein PA (2004) Surgical site infection and the routine use of perioperative hyperoxia in a general surgical population: a randomized controlled trial. JAMA 291(1):79–87. doi:10.1001/jama.291.1.79 Takeishi K, Yamashita Y, Tsujita E, Maeda T, Tsutsui S, Matsuda H, Shirabe K, Ishida T, Maehara Y (2014) Risk factors for organ/space surgical site infection after hepatectomy for hepatocellular carcinoma. Am Surg 80(11):1173–1175 Rasouli MR, Restrepo C, Maltenfort MG, Purtill JJ, Parvizi J (2014) Risk factors for surgical site infection following total joint arthroplasty. J Bone Joint Surg Am 96(18):e158. doi:10.2106/JBJS.M.01363 Bykowski MR, Sivak WN, Cray J, Buterbaugh G, Imbriglia JE, Lee WP (2011) Assessing the impact of antibiotic prophylaxis in outpatient elective hand surgery: a single-center, retrospective review of 8,850 cases. J Hand Surg [Am] 36(11):1741–1747. doi:10.1016/ j.jhsa.2011.08.005 Harness NG, Inacio MC, Pfeil FF, Paxton LW (2010) Rate of infection after carpal tunnel release surgery and effect of antibiotic prophylaxis. J Hand Surg [Am] 35(2):189–196. doi:10.1016/j.jhsa. 2009.11.012 Hashemi K, Blakeley CJ (2004) Wound infections in day-case hand surgery: a prospective study. Ann R Coll Surg Engl 86(6):449–450. doi:10.1308/147870804687 Zwiebel S, Becker D (2014) Risk of postoperative infection following carpal tunnel release in patients with diabetes mellitus: a review of 658 surgeries. Plast Reconstr Surg 134(4 Suppl 1):37. doi:10. 1097/01.prs.0000455366.67857.24 Grayson MJ, Saldana MJ (1987) Toxic shock syndrome complicating surgery of the hand. J Hand Surg [Am] 12(6):1082–1084 Rigopoulos N, Dailiana ZH, Varitimidis S, Hantes M, Bargiotas K, Malizos KN (2008) Compartmental infections of the hand. Scand J Plast Reconstr Surg Hand Surg 42(1):38–42. doi:10.1080/ 02844310701553967 Smith PA, Hankin FM, Louis DS (1986) Postoperative toxic shock syndrome after reconstructive surgery of the hand. J Hand Surg [Am] 11(3):399–402
International Orthopaedics (SICOT) 26.
Agency for Healthcare Research and Quality (AHRQ) Healthcare Cost and Utilization Project (HCUP) Databases. AHRQ website. http://www.hcup-us.ahrq.gov/databases.jsp. Accessed 1 November 2014. 27. Martin CT, Pugely AJ, Gao Y, Ilgenfritz RM, Weinstein SL (2014) Incidence and risk factors for early wound complications after spinal arthrodesis in children: analysis of 30-day follow-up data from the ACS-NSQIP. Spine (Phila Pa 1976) 39(18):1463–1470. doi:10. 1097/BRS.0000000000000446 28. Hayward RA, Hofer TP (2001) Estimating hospital deaths due to medical errors: preventability is in the eye of the reviewer. JAMA 286(4):415–420 29. Simborg DW (1981) DRG creep: a new hospital-acquired disease. N Engl J Med 304(26):1602–1604. doi:10.1056/ NEJM198106253042611 30. Curtin CM, Hernandez-Boussard T (2014) Readmissions after treatment of distal radius fractures. J Hand Surg [Am] 39(10): 1926–1932. doi:10.1016/j.jhsa.2014.07.041 31. Bruijnzeel H, Neuhaus V, Fostvedt S, Jupiter JB, Mudgal CS, Ring DC (2012) Adverse events of open A1 pulley release for idiopathic trigger finger. J Hand Surg [Am] 37(8):1650–1656. doi:10.1016/j. jhsa.2012.05.014
32.
33.
34.
35.
36.
37.
Manoso MW, Cizik AM, Bransford RJ, Bellabarba C, Chapman J, Lee MJ (2014) Medicaid status is associated with higher surgical site infection rates after spine surgery. Spine (Phila Pa 1976) 39(20): 1707–1713. doi:10.1097/BRS.0000000000000496 LaPar DJ, Bhamidipati CM, Mery CM, Stukenborg GJ, Jones DR, Schirmer BD, Kron IL, Ailawadi G (2010) Primary payer status affects mortality for major surgical operations. Ann Surg 252(3): 544–550. doi:10.1097/SLA.0b013e3181e8fd75, discussion 550-541 Menendez ME, Ring D (2014) Minorities are less likely to receive autologous blood transfusion for major elective orthopaedic surgery. Clin Orthop Relat Res 472(11):3559–3566. doi:10.1007/ s11999-014-3793-5 Menendez ME, van Dijk CN, Ring D (2014) Who leaves the hospital against medical advice in the orthopaedic setting? Clin Orthop Relat Res 473(3):1140–1149. doi:10.1007/s11999-014-3924-z Taubman SL, Allen HL, Wright BJ, Baicker K, Finkelstein AN (2014) Medicaid increases emergency-department use: evidence from Oregon's Health Insurance Experiment. Science 343(6168): 263–268. doi:10.1126/science.1246183 Mondelli M, Padua L, Reale F, Signorini AM, Romano C (2004) Outcome of surgical release among diabetics with carpal tunnel syndrome. Arch Phys Med Rehabil 85(1):7–13
