Journal of Infection and Public Health (2015) 8, 127—135
Incidence and attributable costs of ventilator-associated pneumonia (VAP) in a tertiary-level intensive care unit (ICU) in northern India Ashu Sara Mathai a,∗, Atul Phillips a, Paramdeep Kaur b, Rajesh Isaac b a
Department of Anaesthesiology and Critical Care, Christian Medical College, Ludhiana 141008, Punjab, India b Department of Community Medicine, Christian Medical College, Ludhiana 141008, Punjab, India Received 2 February 2014 ; received in revised form 5 May 2014; accepted 11 July 2014
KEYWORDS Ventilator-associated pneumonia; Attributable costs; Intensive care unit
Abstract Background: Ventilator-associated pneumonia (VAP) is the most common nosocomial infection acquired by patients in the intensive care unit (ICU). However, the economic effects of such infections remain unclear particularly in developing countries. Methods: Patients who were mechanically ventilated for more than 48 h in the ICU were studied for the occurrence of VAP. Total drug costs and hospital costs were noted, and attributable costs were calculated after adjusting for potential confounders. Results: Ninety-five (38%) patients who were ventilated for more than 48 h developed VAP, which resulted in an incidence of 40.1 VAP infections/1000 mechanical ventilation days. The patients with VAP experienced significantly longer hospital stay [21 (IQ = 14—33) days versus 11 (IQ = 6—18) days, P < 0.0001)] and incurred greater hospital costs [USD $6250.92 (IQ = 3525.39—9667.57) versus $2598.84 (IQ = 1644.33—4477.65), P < 0.0001]. Multiple regression analysis revealed that the cost-driving factors in our study population were the occurrence of VAP infections (P < 0.0001) and the duration of hospital stay (P < 0.0001). The attributable cost of VAP infection was calculated to be USD $5200 (95% CI = 3245—7152).
∗
Corresponding author. Tel.: +91 9888500240/161 2226506; fax: +91 161 5050599. E-mail addresses: [email protected] (A.S. Mathai), [email protected] (A. Phillips), [email protected] (P. Kaur), [email protected] (R. Isaac). http://dx.doi.org/10.1016/j.jiph.2014.07.005 1876-0341/© 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Limited. All rights reserved.
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A.S. Mathai et al. Conclusion: We conclude that VAP significantly increases the costs of treatment in low-income developing countries. This study highlights the need to implement urgent measures to reduce the incidence of this disease in ICUs. © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Limited. All rights reserved.
Introduction Ventilator-associated pneumonia (VAP) is the leading cause of nosocomial infection in intensive care unit (ICU) patients. While the international nosocomial infection control consortium (INICC) data suggests that the incidence of VAP is as high as 13.6/1000 mechanical ventilator (MV) days [1], the occurrence of VAP in Asian countries is much higher and ranges from 3.5 to 46 infections/1000 MV days [2]. In US hospitals, VAP is the second most costly nosocomial infection at $40,144 (95% CI, $36,286—44,220) [3]. Similarly, in developing countries, the total costs attributed to patients with VAP infections are nearly five-fold higher than those of other patients [4]. Given the paucity of available data from the Asian subcontinent and the potential significance of the economic burden imposed by this common nosocomial infection, we conducted a prospective audit of all VAP infections that were acquired in our ICU. The primary objective of this audit was to study the incidence and the attributable costs of VAP infections. Additionally, we sought to study the microbiological characteristics of these infections and the outcomes of patients who developed VAP infections.
Materials and methods Setting and subjects We conducted this prospective observational study in an adult, tertiary-level ICU in northern India over one year (October 1, 2010 to September 30, 2011). Our ICU is a mixed medical-surgical, tertiary level ICU with approximately 900—1000 admissions per year. After receiving approval from the institutional ethics review board, we studied all of the adult patients who were intubated and mechanically ventilated for more than 48 h. We excluded patients who were already intubated and those who were on mechanical ventilation for more than 12 h prior to ICU admission.
Data collection After admission into the ICU, we noted the basic demographic details, including age, gender, Acute
Physiology and Chronic Health Evaluation (APACHE II) score at admission, category of admission, diagnosis at admission, and the presence of any comorbid illnesses, of all of the included patients. We also noted any histories of addictions, including smoking, alcohol intake, and the use of narcotic or immunosuppressive drugs. All of the included patients were evaluated daily for clinical signs of VAP using the Centers for Disease Control and Prevention (CDC) criteria. The clinical pulmonary infection score (CPIS) was calculated on the day of clinical suspicion of VAP and on the third day after that. CPIS scores ≥6 were considered to be significant. For all patients with suspected VAP, we collected respiratory samples by blind deep endotracheal aspiration and followed the culture results to note the patterns of infection and the resistance characteristics of the isolated organisms. We also followed up all patients to note their outcomes (i.e., discharge or death) and the total durations of their stays in the ICU and the hospital. The final bills of patients were accessed to study the drug costs and total hospital costs that were incurred.
Terminology Ventilator-associated pneumonia (VAP) was defined by the novel onset of pneumonia in ventilated patients over the period of 48 h from the initiation of mechanical ventilation until 48 h after extubation. Early onset VAP was defined as VAP that developed in ventilated patients within the first four days ( 48 hrs)
65 non survivors (68%)
155 non VAP (62%) 30 survivors (32%)
patients (149, 59.6%) were males, and the mean patient age was 53.60 (±SD 18.03) years. The average APACHE II score at admission was 20.74 (±SD 6.75), and the majority of patients (192, 76.8%) were admitted under the medical category. A total of 95 (38%) patients developed VAP during the study period, which resulted in an incidence of 40.1 episodes of infection/1000 mechanical ventilation (MV) days. The device utilization ratio was 0.85. While there were no associations between VAP and any comorbid illnesses (e.g., such as diabetes mellitus and hypertension), the male patients were found to be at a greater risk for developing VAP infections (Table 1). The majority of VAP episodes (65 patients, 69%) were late infections (i.e., infections acquired after 5 days of ventilation).
Microbiological characteristics and resistance patterns
Demographic characteristics
95 VAP (38%)
Fig. 2 Microbiological organisms isolated from the patients with VAP infections (with percentages). Gramnegative organisms caused a large majority of the VAP infections, and Acinetobacter was the single most frequently isolated species.
94 non survivors (60%)
61 survivors (40%)
Fig. 1 Flow chart illustrating the screening and selection processes and the outcomes of the studied patients.
The majority of the VAP cases (87.15%) were caused by Gram-negative organisms such as Acinetobacter (58 isolates, 53.2%), Klebsiella (15.6%) and Pseudomonas species (12.8%). Cultures yielded gram-positive organisms in only five instances, and these organisms included methicillin-resistant Staphylococcus aureus (MRSA) in four patients (Fig. 2). Ventilator-associated pneumonia was caused by multidrug-resistant (MDR) organisms in 26 (27.3%) patients. There were high proportions of extended spectrum  lactamase (ESBL)-producing strains among the Klebsiella species (13 isolates, 76.5%) and the Escherichia coli (5 isolates, 55.55%) strains. While all strains of Acinetobacter were MDR organisms, 25 of these isolates (43.1%) were resistant to even the carbapenem group of antibiotics. A significant number of Klebsiella (12 isolates, 70%)
130
A.S. Mathai et al.
Table 1
Univariate analysis of the demographic characteristics between patients with VAP and without VAP. VAPa (n = 95)
non-VAP (n = 155)
55.49 ± 17.45
52.43 ± 18.40
0.19
65 (68%)
84 (54%)
0.03
21.41 ± 6.73
20.32 ± 6.75
0.21
72/23
120/35
0.18
33 50 27 13 17 20 22 11
56 71 33 19 18 21 27 18
0.82 0.29 0.20 0.74 0.16 0.12 0.26 0.99
Characteristics Age (years) (mean ± SDc ) Gender (Males) APACHE II (mean ± SDc ) Type of admission (medical/surgical) Co-morbidities Diabetes Hypertension IHDd Obesity COPDe Smoking Alcoholism Steroid use a b c d e
(35%) (53%) (28%) (14%) (18%) (21%) (23%) (12%)
(36%) (46%) (21%) (12%) (12%) (14%) (17%) (12%)
Pb value
VAP — ventilator associated pneumonia. P value < 0.05 was considered significant. SD — standard deviation. IHD — ischemic heart disease. COPD — chronic obstructive heart disease.
and Pseudomonas (4 isolates, 28.5%) isolates also exhibited resistance to carbapenems.
both the ICU and the hospital for longer durations (P < 0.0001; Table 2).
Outcomes
Costs incurred
The crude in-hospital mortality rates were similar between the VAP and non-VAP patients. However, the patients with VAP infections were mechanically ventilated for longer durations and stayed in
We found that the total costs incurred for treatment and medications were significantly higher among the VAP patients than the patients without VAP (P < 0.0001; Table 2). When we further
Table 2
Univariate analysis of the outcome variables between patients with VAP versus non-VAP.
Variables
APACHE IId Total MVe days LOSf ICU Hospital Costs incurred Total (US$) Drugs (US$) Mortality a b c d e f
VAPa
non VAP
n = 95 Median (IQc )
n = 155 Median (IQc )
Pb value
22 (15—26) 12 (8—19)
21 (14—26) 4 (4—7)
0.26 < 0.0001
13 (10—21) 21 (14—33)
6 (4—8) 11 (6—18)
< 0.0001
Incidence and attributable costs of ventilator-associated pneumonia (VAP) in a tertiary-level intensive care unit (ICU) in northern India Ashu Sara Mathai a,∗, Atul Phillips a, Paramdeep Kaur b, Rajesh Isaac b a
Department of Anaesthesiology and Critical Care, Christian Medical College, Ludhiana 141008, Punjab, India b Department of Community Medicine, Christian Medical College, Ludhiana 141008, Punjab, India Received 2 February 2014 ; received in revised form 5 May 2014; accepted 11 July 2014
KEYWORDS Ventilator-associated pneumonia; Attributable costs; Intensive care unit
Abstract Background: Ventilator-associated pneumonia (VAP) is the most common nosocomial infection acquired by patients in the intensive care unit (ICU). However, the economic effects of such infections remain unclear particularly in developing countries. Methods: Patients who were mechanically ventilated for more than 48 h in the ICU were studied for the occurrence of VAP. Total drug costs and hospital costs were noted, and attributable costs were calculated after adjusting for potential confounders. Results: Ninety-five (38%) patients who were ventilated for more than 48 h developed VAP, which resulted in an incidence of 40.1 VAP infections/1000 mechanical ventilation days. The patients with VAP experienced significantly longer hospital stay [21 (IQ = 14—33) days versus 11 (IQ = 6—18) days, P < 0.0001)] and incurred greater hospital costs [USD $6250.92 (IQ = 3525.39—9667.57) versus $2598.84 (IQ = 1644.33—4477.65), P < 0.0001]. Multiple regression analysis revealed that the cost-driving factors in our study population were the occurrence of VAP infections (P < 0.0001) and the duration of hospital stay (P < 0.0001). The attributable cost of VAP infection was calculated to be USD $5200 (95% CI = 3245—7152).
∗
Corresponding author. Tel.: +91 9888500240/161 2226506; fax: +91 161 5050599. E-mail addresses: [email protected] (A.S. Mathai), [email protected] (A. Phillips), [email protected] (P. Kaur), [email protected] (R. Isaac). http://dx.doi.org/10.1016/j.jiph.2014.07.005 1876-0341/© 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Limited. All rights reserved.
128
A.S. Mathai et al. Conclusion: We conclude that VAP significantly increases the costs of treatment in low-income developing countries. This study highlights the need to implement urgent measures to reduce the incidence of this disease in ICUs. © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Limited. All rights reserved.
Introduction Ventilator-associated pneumonia (VAP) is the leading cause of nosocomial infection in intensive care unit (ICU) patients. While the international nosocomial infection control consortium (INICC) data suggests that the incidence of VAP is as high as 13.6/1000 mechanical ventilator (MV) days [1], the occurrence of VAP in Asian countries is much higher and ranges from 3.5 to 46 infections/1000 MV days [2]. In US hospitals, VAP is the second most costly nosocomial infection at $40,144 (95% CI, $36,286—44,220) [3]. Similarly, in developing countries, the total costs attributed to patients with VAP infections are nearly five-fold higher than those of other patients [4]. Given the paucity of available data from the Asian subcontinent and the potential significance of the economic burden imposed by this common nosocomial infection, we conducted a prospective audit of all VAP infections that were acquired in our ICU. The primary objective of this audit was to study the incidence and the attributable costs of VAP infections. Additionally, we sought to study the microbiological characteristics of these infections and the outcomes of patients who developed VAP infections.
Materials and methods Setting and subjects We conducted this prospective observational study in an adult, tertiary-level ICU in northern India over one year (October 1, 2010 to September 30, 2011). Our ICU is a mixed medical-surgical, tertiary level ICU with approximately 900—1000 admissions per year. After receiving approval from the institutional ethics review board, we studied all of the adult patients who were intubated and mechanically ventilated for more than 48 h. We excluded patients who were already intubated and those who were on mechanical ventilation for more than 12 h prior to ICU admission.
Data collection After admission into the ICU, we noted the basic demographic details, including age, gender, Acute
Physiology and Chronic Health Evaluation (APACHE II) score at admission, category of admission, diagnosis at admission, and the presence of any comorbid illnesses, of all of the included patients. We also noted any histories of addictions, including smoking, alcohol intake, and the use of narcotic or immunosuppressive drugs. All of the included patients were evaluated daily for clinical signs of VAP using the Centers for Disease Control and Prevention (CDC) criteria. The clinical pulmonary infection score (CPIS) was calculated on the day of clinical suspicion of VAP and on the third day after that. CPIS scores ≥6 were considered to be significant. For all patients with suspected VAP, we collected respiratory samples by blind deep endotracheal aspiration and followed the culture results to note the patterns of infection and the resistance characteristics of the isolated organisms. We also followed up all patients to note their outcomes (i.e., discharge or death) and the total durations of their stays in the ICU and the hospital. The final bills of patients were accessed to study the drug costs and total hospital costs that were incurred.
Terminology Ventilator-associated pneumonia (VAP) was defined by the novel onset of pneumonia in ventilated patients over the period of 48 h from the initiation of mechanical ventilation until 48 h after extubation. Early onset VAP was defined as VAP that developed in ventilated patients within the first four days ( 48 hrs)
65 non survivors (68%)
155 non VAP (62%) 30 survivors (32%)
patients (149, 59.6%) were males, and the mean patient age was 53.60 (±SD 18.03) years. The average APACHE II score at admission was 20.74 (±SD 6.75), and the majority of patients (192, 76.8%) were admitted under the medical category. A total of 95 (38%) patients developed VAP during the study period, which resulted in an incidence of 40.1 episodes of infection/1000 mechanical ventilation (MV) days. The device utilization ratio was 0.85. While there were no associations between VAP and any comorbid illnesses (e.g., such as diabetes mellitus and hypertension), the male patients were found to be at a greater risk for developing VAP infections (Table 1). The majority of VAP episodes (65 patients, 69%) were late infections (i.e., infections acquired after 5 days of ventilation).
Microbiological characteristics and resistance patterns
Demographic characteristics
95 VAP (38%)
Fig. 2 Microbiological organisms isolated from the patients with VAP infections (with percentages). Gramnegative organisms caused a large majority of the VAP infections, and Acinetobacter was the single most frequently isolated species.
94 non survivors (60%)
61 survivors (40%)
Fig. 1 Flow chart illustrating the screening and selection processes and the outcomes of the studied patients.
The majority of the VAP cases (87.15%) were caused by Gram-negative organisms such as Acinetobacter (58 isolates, 53.2%), Klebsiella (15.6%) and Pseudomonas species (12.8%). Cultures yielded gram-positive organisms in only five instances, and these organisms included methicillin-resistant Staphylococcus aureus (MRSA) in four patients (Fig. 2). Ventilator-associated pneumonia was caused by multidrug-resistant (MDR) organisms in 26 (27.3%) patients. There were high proportions of extended spectrum  lactamase (ESBL)-producing strains among the Klebsiella species (13 isolates, 76.5%) and the Escherichia coli (5 isolates, 55.55%) strains. While all strains of Acinetobacter were MDR organisms, 25 of these isolates (43.1%) were resistant to even the carbapenem group of antibiotics. A significant number of Klebsiella (12 isolates, 70%)
130
A.S. Mathai et al.
Table 1
Univariate analysis of the demographic characteristics between patients with VAP and without VAP. VAPa (n = 95)
non-VAP (n = 155)
55.49 ± 17.45
52.43 ± 18.40
0.19
65 (68%)
84 (54%)
0.03
21.41 ± 6.73
20.32 ± 6.75
0.21
72/23
120/35
0.18
33 50 27 13 17 20 22 11
56 71 33 19 18 21 27 18
0.82 0.29 0.20 0.74 0.16 0.12 0.26 0.99
Characteristics Age (years) (mean ± SDc ) Gender (Males) APACHE II (mean ± SDc ) Type of admission (medical/surgical) Co-morbidities Diabetes Hypertension IHDd Obesity COPDe Smoking Alcoholism Steroid use a b c d e
(35%) (53%) (28%) (14%) (18%) (21%) (23%) (12%)
(36%) (46%) (21%) (12%) (12%) (14%) (17%) (12%)
Pb value
VAP — ventilator associated pneumonia. P value < 0.05 was considered significant. SD — standard deviation. IHD — ischemic heart disease. COPD — chronic obstructive heart disease.
and Pseudomonas (4 isolates, 28.5%) isolates also exhibited resistance to carbapenems.
both the ICU and the hospital for longer durations (P < 0.0001; Table 2).
Outcomes
Costs incurred
The crude in-hospital mortality rates were similar between the VAP and non-VAP patients. However, the patients with VAP infections were mechanically ventilated for longer durations and stayed in
We found that the total costs incurred for treatment and medications were significantly higher among the VAP patients than the patients without VAP (P < 0.0001; Table 2). When we further
Table 2
Univariate analysis of the outcome variables between patients with VAP versus non-VAP.
Variables
APACHE IId Total MVe days LOSf ICU Hospital Costs incurred Total (US$) Drugs (US$) Mortality a b c d e f
VAPa
non VAP
n = 95 Median (IQc )
n = 155 Median (IQc )
Pb value
22 (15—26) 12 (8—19)
21 (14—26) 4 (4—7)
0.26 < 0.0001
13 (10—21) 21 (14—33)
6 (4—8) 11 (6—18)
< 0.0001
