j o u r n a l o f s u r g i c a l r e s e a r c h x x x ( 2 0 1 5 ) 1 e5
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.JournalofSurgicalResearch.com
The diagnostic dilemma of identifying perforated appendicitis Zehra Farzal, BS,a Zainab Farzal, BS,a Nudrat Khan, BS,b and Anne Fischer, MD, PhDb,*,1 a b
UT Southwestern Medical Center, Dallas, Texas Department of Pediatric Surgery, Children’s Medical Center, Dallas, Texas
article info
abstract
Article history:
Background: Despite extensive research, the classification of perforated (PA) versus non-
Received 15 January 2015
perforated appendicitis (NPA) remains poorly defined. We hypothesize that the variability
Received in revised form
across specialties in the classification of appendicitis as PA or NPA may be associated with
16 March 2015
variation in clinical behavior as demonstrated by a variation in length of stay (LOS).
Accepted 15 April 2015
Methods: Retrospective review of 1311 appendectomies over a 16-mo period from an
Available online xxx
independent children’s hospital allowed a comparison of the diagnostic classification of appendicitis as PA or NPA based on radiology (R), operative (O), and pathology (P) reports.
Keywords:
Three groups, P þ O (n ¼ 1241), P þ R (n ¼ 516), O þ R (n ¼ 512) were compared to identify
Perforated appendicitis
interspecialty discordance in classification. The LOS was analyzed as a proxy for clinical
Pediatric
behavior to test if the diagnostic classification was consistent with expected clinical
Discordance
behavior (NPA with LOS 48 h and PA with LOS >48 h).
Cost effectiveness
Results: The subsets P þ O, P þ R, and O þ R revealed a discordance of 11%, 15.7%, and 16.6% within the classification of appendicitis, respectively. Cases designated as PA in all subsets clinically behaved as PA with a mean LOS >48 h (97, 95, and 95 h, respectively), whereas the cases designated as NPA exhibited greater variation from the expected LOS 48 h, with means 35, 83, and 62 h, respectively. Conclusions: Variability in the classification of appendicitis between specialties suggests an error rate inherent in diagnosis. Standardizing the criteria for classification across specialties may improve the diagnostic accuracy of the type of appendicitis needed to identify best practices for optimal use of hospital resources and for meaningful clinical trials. ª 2015 Elsevier Inc. All rights reserved.
1.
Introduction
Appendicitis is known to be the most common surgical emergency in children. Peak incidence occurs between the ages of 11e12 y with a lifetime risk of 7% for females and 9% for males [1]. Approximately one-third of children have
perforation at the time of surgery [2]. Being able to correctly distinguish between cases of perforated (PA) and nonperforated appendicitis (NPA) holds tremendous value in terms of applying correct clinical guidelines for antibiotic therapy and expected hospitalization. The lack of accuracy in the classification of appendicitis can affect the therapeutic
* Corresponding author. Department of Pediatric Surgery, Beaumont Children’s Hospital, 3535 W. Thirteen Mile Road, Suite 748, Royal Oak, MI 48073. Tel.: þ1 248 551 7707; fax: þ1 248 551 6556. E-mail address: [email protected] (A. Fischer). 1 Present address: Department of Pediatric Surgery, Beaumont Children’s Hospital, 3535 W. Thirteen Mile Road, Suite 748, Royal Oak, MI 48073. 0022-4804/$ e see front matter ª 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jss.2015.04.058
2
j o u r n a l o f s u r g i c a l r e s e a r c h x x x ( 2 0 1 5 ) 1 e5
course and the readmissions. For example, PA more commonly requires a longer course of postoperative antibiotics depending on the patient’s clinical course and may lead to postoperative complications such as the development of intra-abdominal abscesses. The associated costs are also a concern with the average cost per case of complicated appendicitis being $12,300, whereas cases of uncomplicated appendicitis are approximately one-half of that amount at $6355 per case [3]. Radiology, surgery, and pathology are all specialties involved with diagnosing PA and NPA. Despite numerous clinical trials on pediatric appendicitis in the Cochrane database over the last decade, no defined best clinical pathway exists for managing complicated appendicitis or PA causing a tremendous variation in practice and outcomes [4]. We hypothesize that the variability across specialties in the classification of appendicitis as PA may be associated with variation in clinical behavior as demonstrated by a variation in length of stay (LOS).
2.
2.2. Comparison of diagnostic classification to clinical behavior Next, LOS was used as an approximate proxy of clinical behavior with the expectation that NPA cases would typically require a LOS 48 h. Similarly, cases classified as PA were expected to require a length of stay >48 h. The LOS in each group was analyzed to see if the classification as “PA” or “NPA” was consistent with the clinical behavior exhibited.
3.
Results
3.1.
Patient characteristics
Materials and methods
We conducted an institutional review boardeapproved (072011-039) retrospective review of 1311 appendectomies performed over a 16-mo period in 2010 and 2011 at a large independent academic children’s hospital. Demographics (age and gender), symptoms at presentation (nausea, vomiting, abdominal pain, anorexia, fever, and diarrhea), duration of symptoms, LOS, and use of postoperative antibiotics were obtained from the electronic medical record. Diagnoses of PA or NPA according to radiology (R), operative (O), and pathology (P) reports were recorded and compared. For radiologic imaging, only cases with CT imaging were included to give the most precise radiologic diagnosis. Differentiating between PA and NPA types was key in this study, and although useful, ultrasound reads can be equivocal in differentiating between PA and NPA types, leading to exclusion of cases without CT scans. Appendicitis was classified as “PA” or “NPA” based on each specialty’s designation, as the goal was to compare the diagnosis determined by each specialist. In radiology reports and operative reports, if terms such as perforated and ruptured were used by the physician, the case was designated as “PA.” In pathology reports, the terms perforation, microperforation, and rupture were all words identifying a “hole” in the appendix, and thus were consistent with the classification of “PA.” We did not superimpose a fourth definition because it would be arbitrary, given that the intent of this study was to assess the actual lack of uniformity in distinguishing PA from NPA in radiologic, pathologic, and intraoperative determinations. Exclusion criteria included interval appendectomies, open appendectomies, incomplete data sets and those with inconclusive findings on these reports.
2.1.
(n ¼ 1241), pathology and radiology (P þ R) group (n ¼ 516), and operative and radiology (O þ R) group (n ¼ 512). For the radiology arm, only cases with CT scans were analyzed for the most definitive determination of diagnosis, explaining the smaller sample size for the P þ R and O þ R groups. For each of the three groups, the percentage of discordant cases between the diagnoses of PA and NPA between specialties was calculated.
A total of 1311 appendectomies done at the Dallas Children’s Medical Center were analyzed. In the P þ O group, 1261 remained after exclusion of open and interval appendectomies and cases with incomplete information. From the 550 cases with available CT reports, 516 and 512 cases remained in the P þ R group and O þ R groups respectively, after exclusion of cases with incomplete information. The demographics are listed in the Table below.
3.2.
Interspecialty discordance and clinical behavior
The subsets P þ O, P þ R, and O þ R revealed a discordance of 11%, 15.7%, and 16.6%, respectively (Table). Therefore, the P þ O group was the most concordant subset because pathology and operative reports most frequently concurred with the classification of the type of appendicitis. To compare the diagnostic classification to the actual clinical behavior, cases
Table e Subset demographics and characteristics. Demographics and discordance N Age Female, % Male, % Discordant cases % Discordance
PþR
OþR
1241 10.3 3.7 40 60 138 11
516 10.3 3.8 43 57 81 15.7
512 10.3 3.8 43 57 85 16.6
Characteristics of discordant cases
Interspecialty subset analysis
To conduct interspecialty analysis of the diagnosis of PA versus NPA, the appendectomy cases (n ¼ 1311) were divided into three subsets: pathology and operative (P þ O) group
PþO
# Perforated % Perforated
P þ O (138)
P þ R (81)
O þ R (85)
P
O
P
R
O
R
36 26
102 74
46 57
35 43
65 76
20 24
j o u r n a l o f s u r g i c a l r e s e a r c h x x x ( 2 0 1 5 ) 1 e5
Fig. 1 e Average LOS for perforated versus acute nonperforated appendectomies. The mean LOS (in hours) for cases designated as “PA” and “NPA.” The numerical value above each group depicts the LOS in hours. The median LOS (in hours) for each set is as follows: P D O: PA [ 85, NPA [ 34; P D R: PA [ 79, NPA [ 69; and O D R: PA [ 86, NPA [ 41.5. (Color version of figure is available online.)
Most of the PA cases (especially those in the O þ R subset with a mean of 95 h and P þ R subset also with a mean of 95 h) had an LOS >48 h and clinically behaved as expected for PA cases. The P þ O subset was most consistent with the expected clinical behavior with PA cases having an LOS well above 48 h (mean of 97 h) and NPA cases requiring an LOS under 48 h (mean of 35). This finding also supports our earlier finding of the P þ O group having the most concordance in diagnosis. The analysis of the O þ R group in Figure 2 illustrates the variation in clinical behavior of the cases with the most discordance, graphed according to the operative diagnosis they were given. Some cases designated as “NPA” required an LOS much >48 h. Similarly, there are several cases that were designated as “PA” that required an LOS 48 h (97, 95, and 95 h, respectively). The group designated as NPA exhibited greater variation from the expected LOS 48 h, with means of 35, 83, and 62 h, respectively (Fig. 1). In terms of LOS, deviations from the expected outcome were pictorialized: PA cases having an LOS >48 h and NPA having an LOS 48 h (Fig. 1). The largest deviation in expected clinical behavior for NPA cases were found in the P þ R group (range 9e235 h, mean 83 h) and the O þ R group (range 9e161 h, mean 62 h). The mean in both groups suggests a clinical behavior more consistent with being perforated. This large deviation in clinical behavior trended with the two categories with the highest diagnostic discordance.
3
Discussion
Postoperative complications such as wound infections and intra-abdominal abscesses for appendicitis during the childhood years have remained high and appear to be higher in PA cases [5,6]. These complications may lead to readmissions, which further contribute to an increase in health care costs. Given an incidence of approximately 70,000 cases of pediatric appendicitis per year in the United States, readmissions alone may cost up to $20 million with associated charges that exceed $100 million [3,7]. A recent study demonstrated a prominent difference in readmission rates based on the severity and treatment in patients who presented with appendicitis. Those who were treated for complicated appendicitis were found to be more likely to be readmitted postoperatively compared with uncomplicated cases [3].
Fig. 2 e LOS for cases designated as PA or NPA in the O D R group graphed according to the designated operative diagnosis The dotted line denotes the 48 h used as a proxy for clinical behavior. (Color version of figure is available online.)
4
j o u r n a l o f s u r g i c a l r e s e a r c h x x x ( 2 0 1 5 ) 1 e5
The lack of standardized criteria for diagnosis of PA poses a challenge for optimizing clinical guidelines to best avoid readmissions. Recent studies have revealed tremendous variation across children’s hospitals nationally with little consensus on best practice with regards to pediatric appendicitis [8]. Also newer studies are advocating for rapid discharge for simple appendicitis [9], which clearly requires diagnostic certainty. Similarly, a study found great interobserver variation among surgeons in identifying PA intraoperatively with only 27% agreement [10]. Recent studies have defined a perforation as a macroscopic hole in the appendix or a fecalith in the abdomen to avoid lack of clarity in diagnosing PA. The authors found this particular definition to be effective in identifying the patients at risk for postoperative abscess formation [11] and thus a clinically relevant descriptive. Of note, the standard of care of appendicitis does not necessitate emergently rushing each patient to the operating room on obtaining a diagnosis, so there remains a possibility of rupture between the computed tomography (CT) scan and the surgery in the small fraction of children admitted late at night for surgery in the morning. This time delay may contribute to a higher discordance seen in the O þ R group, when compared with the other two subsets. The imaging study of choice can further confound diagnostic accuracy because ultrasound is less effective in correctly diagnosing appendicitis compared with CT [12e14], even though it is usually the first and frequently the only imaging modality used when a patient presents with symptoms indicative of appendicitis. This is why we included only those radiology reports that were CT based to obtain the best accuracy. Hence, the two subsets with radiology reports had a smaller sample size because cases with only ultrasounds were excluded given that ultrasound reads can be “indeterminate” or “equivocal” with regards to perforations. It should be noted that if cases with only ultrasounds as the imaging modality were included, a greater variability and discordance between the diagnosis of PA and NPA would likely be observed. For this reason, the true discordance in diagnosis may be much greater than was found in our study. Similarly, a currently unpublished study on pediatric appendicitis at our institution found variation in descriptive nomenclature used in pathology reports, which includes terms such as perforated, nonperforated, suppurative, gangrenous, catarrhal, and necrotizing that are used to describe appendicitis but also lack clear definitions, further contributing to discordance in diagnosis. To our knowledge, our study represents the first effort to explore how the lack of standardization of criteria to diagnose PA versus NPA across three specialties is important in management of appendicitis. The uniformity and standardization of criteria to distinguish PA versus NPA appendicitis may be beneficial because the management of these two entities differs greatly. This is the first study to analyze this diagnostic variation across specialties and implies an inherent error rate. Correctly diagnosing and treating the condition at initial presentation may help reduce readmission rates, which may be as high as 8.7% in the 30 d after the appendectomy [3]. Furthermore, standardized criteria are also needed to better control the associated costs and
conduct clinical trials that have meaningful results. With an obvious lack of diagnostic criteria to correctly classify whether a case of appendicitis is PA or NPA, studies and trials that are based on a diagnosis of only PA or only NPA may be invalid and unreliable.
5.
Conclusions
There is significant variability in classification of appendicitis across specialties that is clinically relevant in terms of the LOS, a proxy for clinical behavior and medical costs. Standardizing the criteria for classification across specialties may improve the diagnostic accuracy of the type of appendicitis needed to identify best practices for optimal use of hospital resources, as well as for meaningful clinical trials.
Acknowledgment Authors’ contributions: A.F. served as the research mentor for this study and its design and hypothesis. Ze.F., a third year medical student, conducted the data collection, analysis and interpretation, and manuscript preparation. Za.F., a fourth year medical student, assisted with data collection. Research coordinator N.K. assisted with data collection and technicalities.
Disclosure None.
references
[1] Coran AG, Caldamone AA, Adzick S, Krummel KM, Laberge J, Shamberger R. Appendicitis. Pediatric surgery: expert consult. 7th ed. Philadelphia, PA: Elsevier Mosby; 2012. [2] Lund DP, Murphy EU. Management of perforated appendicitis in children: a decade of aggressive treatment. J Pediatr Surg 1994;29:1130. [3] Rice-Townsend S, Hall M, Barnes JN, Baxter JK, Rangel SJ. Hospital readmission after management of appendicitis at freestanding children’s hospitals: contemporary trends and financial implications. J Pediatr Surg 2012;47:1170. [4] Addis DG, Shaffer N, Fowler BS, et al. The epidemiology of appendicitis and appendectomy in the United States. Am J Epidemiol 1990;32:910. [5] Janik JS, Firor HV. Pediatric appendicitis: a 20-year study of 1,640 children at Cook County (Illinois) Hospital. Arch Surg 1979;114:717. [6] Shandling B, Ein SH, Simpson JS, Stephens CA, Bandi SK. Perforating appendicitis and antibiotics. J Pediatr Surg 1974; 9:79. [7] Hall MJ, DeFrances CJ, Williams SN, et al. National Hospital Discharge Survey: 2007 summary. Natl Health Stat Rep 2010; 24:1. [8] Newman K, Ponsky T, Kittle K, et al. Appendicitis 2000: variability in practice, outcomes, and resource utilization at thirty pediatric hospitals. J Pediatr Surg 2003;38:372.
j o u r n a l o f s u r g i c a l r e s e a r c h x x x ( 2 0 1 5 ) 1 e5
[9] Grewal H, Sweat J, Vazquez WD. Laparoscopic appendectomy in children can be done as a fast-track or same-day surgery. JSLS 2004;8:151. [10] Ponsky TA, Hafi M, Heiss K, et al. Interobserver variation in the assessment of appendiceal perforation. J Laparoendosc Adv Surg Tech 2009;19(Suppl 1):S15. [11] St Peter SD, Sharp SW, Holcomb GW III. An evidence-based definition for perforated appendicitis derived from a prospective randomized trial. J Pediatr Surg 2008;43:2242.
5
[12] Doria AS, Moineddin R, Kellenberger CJ, et al. US or CT for diagnosis of appendicitis in children and adults? A metaanalysis. Radiology 2006;241:83. [13] Balthazar EJ, Birnbaum BA, Yee J, et al. Acute appendicitis: CT and US correlation in 100 patients. Radiology 1994;190:31. [14] Horton MD, Counter SF, Florence MG, et al. A prospective trial of computed tomography and ultrasonography for diagnosing appendicitis in the atypical patient. Am J Surg 2000;179:379.
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.JournalofSurgicalResearch.com
The diagnostic dilemma of identifying perforated appendicitis Zehra Farzal, BS,a Zainab Farzal, BS,a Nudrat Khan, BS,b and Anne Fischer, MD, PhDb,*,1 a b
UT Southwestern Medical Center, Dallas, Texas Department of Pediatric Surgery, Children’s Medical Center, Dallas, Texas
article info
abstract
Article history:
Background: Despite extensive research, the classification of perforated (PA) versus non-
Received 15 January 2015
perforated appendicitis (NPA) remains poorly defined. We hypothesize that the variability
Received in revised form
across specialties in the classification of appendicitis as PA or NPA may be associated with
16 March 2015
variation in clinical behavior as demonstrated by a variation in length of stay (LOS).
Accepted 15 April 2015
Methods: Retrospective review of 1311 appendectomies over a 16-mo period from an
Available online xxx
independent children’s hospital allowed a comparison of the diagnostic classification of appendicitis as PA or NPA based on radiology (R), operative (O), and pathology (P) reports.
Keywords:
Three groups, P þ O (n ¼ 1241), P þ R (n ¼ 516), O þ R (n ¼ 512) were compared to identify
Perforated appendicitis
interspecialty discordance in classification. The LOS was analyzed as a proxy for clinical
Pediatric
behavior to test if the diagnostic classification was consistent with expected clinical
Discordance
behavior (NPA with LOS 48 h and PA with LOS >48 h).
Cost effectiveness
Results: The subsets P þ O, P þ R, and O þ R revealed a discordance of 11%, 15.7%, and 16.6% within the classification of appendicitis, respectively. Cases designated as PA in all subsets clinically behaved as PA with a mean LOS >48 h (97, 95, and 95 h, respectively), whereas the cases designated as NPA exhibited greater variation from the expected LOS 48 h, with means 35, 83, and 62 h, respectively. Conclusions: Variability in the classification of appendicitis between specialties suggests an error rate inherent in diagnosis. Standardizing the criteria for classification across specialties may improve the diagnostic accuracy of the type of appendicitis needed to identify best practices for optimal use of hospital resources and for meaningful clinical trials. ª 2015 Elsevier Inc. All rights reserved.
1.
Introduction
Appendicitis is known to be the most common surgical emergency in children. Peak incidence occurs between the ages of 11e12 y with a lifetime risk of 7% for females and 9% for males [1]. Approximately one-third of children have
perforation at the time of surgery [2]. Being able to correctly distinguish between cases of perforated (PA) and nonperforated appendicitis (NPA) holds tremendous value in terms of applying correct clinical guidelines for antibiotic therapy and expected hospitalization. The lack of accuracy in the classification of appendicitis can affect the therapeutic
* Corresponding author. Department of Pediatric Surgery, Beaumont Children’s Hospital, 3535 W. Thirteen Mile Road, Suite 748, Royal Oak, MI 48073. Tel.: þ1 248 551 7707; fax: þ1 248 551 6556. E-mail address: [email protected] (A. Fischer). 1 Present address: Department of Pediatric Surgery, Beaumont Children’s Hospital, 3535 W. Thirteen Mile Road, Suite 748, Royal Oak, MI 48073. 0022-4804/$ e see front matter ª 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jss.2015.04.058
2
j o u r n a l o f s u r g i c a l r e s e a r c h x x x ( 2 0 1 5 ) 1 e5
course and the readmissions. For example, PA more commonly requires a longer course of postoperative antibiotics depending on the patient’s clinical course and may lead to postoperative complications such as the development of intra-abdominal abscesses. The associated costs are also a concern with the average cost per case of complicated appendicitis being $12,300, whereas cases of uncomplicated appendicitis are approximately one-half of that amount at $6355 per case [3]. Radiology, surgery, and pathology are all specialties involved with diagnosing PA and NPA. Despite numerous clinical trials on pediatric appendicitis in the Cochrane database over the last decade, no defined best clinical pathway exists for managing complicated appendicitis or PA causing a tremendous variation in practice and outcomes [4]. We hypothesize that the variability across specialties in the classification of appendicitis as PA may be associated with variation in clinical behavior as demonstrated by a variation in length of stay (LOS).
2.
2.2. Comparison of diagnostic classification to clinical behavior Next, LOS was used as an approximate proxy of clinical behavior with the expectation that NPA cases would typically require a LOS 48 h. Similarly, cases classified as PA were expected to require a length of stay >48 h. The LOS in each group was analyzed to see if the classification as “PA” or “NPA” was consistent with the clinical behavior exhibited.
3.
Results
3.1.
Patient characteristics
Materials and methods
We conducted an institutional review boardeapproved (072011-039) retrospective review of 1311 appendectomies performed over a 16-mo period in 2010 and 2011 at a large independent academic children’s hospital. Demographics (age and gender), symptoms at presentation (nausea, vomiting, abdominal pain, anorexia, fever, and diarrhea), duration of symptoms, LOS, and use of postoperative antibiotics were obtained from the electronic medical record. Diagnoses of PA or NPA according to radiology (R), operative (O), and pathology (P) reports were recorded and compared. For radiologic imaging, only cases with CT imaging were included to give the most precise radiologic diagnosis. Differentiating between PA and NPA types was key in this study, and although useful, ultrasound reads can be equivocal in differentiating between PA and NPA types, leading to exclusion of cases without CT scans. Appendicitis was classified as “PA” or “NPA” based on each specialty’s designation, as the goal was to compare the diagnosis determined by each specialist. In radiology reports and operative reports, if terms such as perforated and ruptured were used by the physician, the case was designated as “PA.” In pathology reports, the terms perforation, microperforation, and rupture were all words identifying a “hole” in the appendix, and thus were consistent with the classification of “PA.” We did not superimpose a fourth definition because it would be arbitrary, given that the intent of this study was to assess the actual lack of uniformity in distinguishing PA from NPA in radiologic, pathologic, and intraoperative determinations. Exclusion criteria included interval appendectomies, open appendectomies, incomplete data sets and those with inconclusive findings on these reports.
2.1.
(n ¼ 1241), pathology and radiology (P þ R) group (n ¼ 516), and operative and radiology (O þ R) group (n ¼ 512). For the radiology arm, only cases with CT scans were analyzed for the most definitive determination of diagnosis, explaining the smaller sample size for the P þ R and O þ R groups. For each of the three groups, the percentage of discordant cases between the diagnoses of PA and NPA between specialties was calculated.
A total of 1311 appendectomies done at the Dallas Children’s Medical Center were analyzed. In the P þ O group, 1261 remained after exclusion of open and interval appendectomies and cases with incomplete information. From the 550 cases with available CT reports, 516 and 512 cases remained in the P þ R group and O þ R groups respectively, after exclusion of cases with incomplete information. The demographics are listed in the Table below.
3.2.
Interspecialty discordance and clinical behavior
The subsets P þ O, P þ R, and O þ R revealed a discordance of 11%, 15.7%, and 16.6%, respectively (Table). Therefore, the P þ O group was the most concordant subset because pathology and operative reports most frequently concurred with the classification of the type of appendicitis. To compare the diagnostic classification to the actual clinical behavior, cases
Table e Subset demographics and characteristics. Demographics and discordance N Age Female, % Male, % Discordant cases % Discordance
PþR
OþR
1241 10.3 3.7 40 60 138 11
516 10.3 3.8 43 57 81 15.7
512 10.3 3.8 43 57 85 16.6
Characteristics of discordant cases
Interspecialty subset analysis
To conduct interspecialty analysis of the diagnosis of PA versus NPA, the appendectomy cases (n ¼ 1311) were divided into three subsets: pathology and operative (P þ O) group
PþO
# Perforated % Perforated
P þ O (138)
P þ R (81)
O þ R (85)
P
O
P
R
O
R
36 26
102 74
46 57
35 43
65 76
20 24
j o u r n a l o f s u r g i c a l r e s e a r c h x x x ( 2 0 1 5 ) 1 e5
Fig. 1 e Average LOS for perforated versus acute nonperforated appendectomies. The mean LOS (in hours) for cases designated as “PA” and “NPA.” The numerical value above each group depicts the LOS in hours. The median LOS (in hours) for each set is as follows: P D O: PA [ 85, NPA [ 34; P D R: PA [ 79, NPA [ 69; and O D R: PA [ 86, NPA [ 41.5. (Color version of figure is available online.)
Most of the PA cases (especially those in the O þ R subset with a mean of 95 h and P þ R subset also with a mean of 95 h) had an LOS >48 h and clinically behaved as expected for PA cases. The P þ O subset was most consistent with the expected clinical behavior with PA cases having an LOS well above 48 h (mean of 97 h) and NPA cases requiring an LOS under 48 h (mean of 35). This finding also supports our earlier finding of the P þ O group having the most concordance in diagnosis. The analysis of the O þ R group in Figure 2 illustrates the variation in clinical behavior of the cases with the most discordance, graphed according to the operative diagnosis they were given. Some cases designated as “NPA” required an LOS much >48 h. Similarly, there are several cases that were designated as “PA” that required an LOS 48 h (97, 95, and 95 h, respectively). The group designated as NPA exhibited greater variation from the expected LOS 48 h, with means of 35, 83, and 62 h, respectively (Fig. 1). In terms of LOS, deviations from the expected outcome were pictorialized: PA cases having an LOS >48 h and NPA having an LOS 48 h (Fig. 1). The largest deviation in expected clinical behavior for NPA cases were found in the P þ R group (range 9e235 h, mean 83 h) and the O þ R group (range 9e161 h, mean 62 h). The mean in both groups suggests a clinical behavior more consistent with being perforated. This large deviation in clinical behavior trended with the two categories with the highest diagnostic discordance.
3
Discussion
Postoperative complications such as wound infections and intra-abdominal abscesses for appendicitis during the childhood years have remained high and appear to be higher in PA cases [5,6]. These complications may lead to readmissions, which further contribute to an increase in health care costs. Given an incidence of approximately 70,000 cases of pediatric appendicitis per year in the United States, readmissions alone may cost up to $20 million with associated charges that exceed $100 million [3,7]. A recent study demonstrated a prominent difference in readmission rates based on the severity and treatment in patients who presented with appendicitis. Those who were treated for complicated appendicitis were found to be more likely to be readmitted postoperatively compared with uncomplicated cases [3].
Fig. 2 e LOS for cases designated as PA or NPA in the O D R group graphed according to the designated operative diagnosis The dotted line denotes the 48 h used as a proxy for clinical behavior. (Color version of figure is available online.)
4
j o u r n a l o f s u r g i c a l r e s e a r c h x x x ( 2 0 1 5 ) 1 e5
The lack of standardized criteria for diagnosis of PA poses a challenge for optimizing clinical guidelines to best avoid readmissions. Recent studies have revealed tremendous variation across children’s hospitals nationally with little consensus on best practice with regards to pediatric appendicitis [8]. Also newer studies are advocating for rapid discharge for simple appendicitis [9], which clearly requires diagnostic certainty. Similarly, a study found great interobserver variation among surgeons in identifying PA intraoperatively with only 27% agreement [10]. Recent studies have defined a perforation as a macroscopic hole in the appendix or a fecalith in the abdomen to avoid lack of clarity in diagnosing PA. The authors found this particular definition to be effective in identifying the patients at risk for postoperative abscess formation [11] and thus a clinically relevant descriptive. Of note, the standard of care of appendicitis does not necessitate emergently rushing each patient to the operating room on obtaining a diagnosis, so there remains a possibility of rupture between the computed tomography (CT) scan and the surgery in the small fraction of children admitted late at night for surgery in the morning. This time delay may contribute to a higher discordance seen in the O þ R group, when compared with the other two subsets. The imaging study of choice can further confound diagnostic accuracy because ultrasound is less effective in correctly diagnosing appendicitis compared with CT [12e14], even though it is usually the first and frequently the only imaging modality used when a patient presents with symptoms indicative of appendicitis. This is why we included only those radiology reports that were CT based to obtain the best accuracy. Hence, the two subsets with radiology reports had a smaller sample size because cases with only ultrasounds were excluded given that ultrasound reads can be “indeterminate” or “equivocal” with regards to perforations. It should be noted that if cases with only ultrasounds as the imaging modality were included, a greater variability and discordance between the diagnosis of PA and NPA would likely be observed. For this reason, the true discordance in diagnosis may be much greater than was found in our study. Similarly, a currently unpublished study on pediatric appendicitis at our institution found variation in descriptive nomenclature used in pathology reports, which includes terms such as perforated, nonperforated, suppurative, gangrenous, catarrhal, and necrotizing that are used to describe appendicitis but also lack clear definitions, further contributing to discordance in diagnosis. To our knowledge, our study represents the first effort to explore how the lack of standardization of criteria to diagnose PA versus NPA across three specialties is important in management of appendicitis. The uniformity and standardization of criteria to distinguish PA versus NPA appendicitis may be beneficial because the management of these two entities differs greatly. This is the first study to analyze this diagnostic variation across specialties and implies an inherent error rate. Correctly diagnosing and treating the condition at initial presentation may help reduce readmission rates, which may be as high as 8.7% in the 30 d after the appendectomy [3]. Furthermore, standardized criteria are also needed to better control the associated costs and
conduct clinical trials that have meaningful results. With an obvious lack of diagnostic criteria to correctly classify whether a case of appendicitis is PA or NPA, studies and trials that are based on a diagnosis of only PA or only NPA may be invalid and unreliable.
5.
Conclusions
There is significant variability in classification of appendicitis across specialties that is clinically relevant in terms of the LOS, a proxy for clinical behavior and medical costs. Standardizing the criteria for classification across specialties may improve the diagnostic accuracy of the type of appendicitis needed to identify best practices for optimal use of hospital resources, as well as for meaningful clinical trials.
Acknowledgment Authors’ contributions: A.F. served as the research mentor for this study and its design and hypothesis. Ze.F., a third year medical student, conducted the data collection, analysis and interpretation, and manuscript preparation. Za.F., a fourth year medical student, assisted with data collection. Research coordinator N.K. assisted with data collection and technicalities.
Disclosure None.
references
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