Abstract

Prevalence of hospital-associated infection is well established in a hospital setting. As a patient safety concern, evaluating and implementing preventive interventions become vital. The present investigation aims at identifying an economic model to determine excess cost from the hospital perspective. The patients included in the study were patients who presented with Surgical Site wound infection (n=50, experiment group) and patients who did not develop the infection (n=25, control group). Length of Intensive Care Unit stay, length of hospital stay and number of antibiotic regimes were significantly increased in the experimental group. The hospital bill showed significant increase in the experiment group. By implementing effective strategies in infection control such as regular hand washing, use of gloves, fumigation of Operation Theatres and Intensive care units and an active surveillance system were effective and cost feasible. On an average Rs 10,000.00 excess was incurred by a patient affected with surgical site infections.

Introduction

Nosocomial, or Hospital-associated infections (HAI) are seen to affect approximately 5% of hospitalized patients.1-3 Hospitals are reservoirs for strains of bacteria that are multi drug resistant strains. There are however effective interventions for reducing the occurrence of HAIs.4-6 But like many events in complex systems, they require changes throughout the hospital and can incur substantial costs on the hospital. In India health care systems closely monitor expenditures and therefore the immediate benefits or cost savings is often a pre-requisite for convincing administrators to support control measures.7 It is therefore important to measure the cost of caring for patients with HAIs and those who are not affected by HAIs.8,9 Studies by Pittet et al., and Rello et al., have focused on patients in the intensive care units.10,11 This population represents the upper extreme of severity of illness and cost. Certain other studies by Wakefield et al., and Kyne et al., have concentrated on organisms and specific sites.12,13

Material and Methods

Sample selection : The study population included patients admitted in the period of January 2004 to December 2004 at the Holdsworth Memorial Hospital, Mysore. The patient groups were the Experiment group (n=50) and the Control group (n=25). The experiment group comprised patients who developed Surgical Site Infections (SSI) during the hospital stay and the control group comprised patients who did not develop SSI during the hospital stay. The patients were matched based on age, gender and the type of ward (semi-private or general ward) they were admitted in.

Measurements: The costs incurred by both the groups were compared for costs incurred on hospital stay- both Intensive Care Unit (ICU) stay and ward stay separately, costs incurred on medicine bills, costs incurred by the attender on travel and the total hospital bill paid (hospital stay bill and medicine bill).

Data collection: Data was obtained from patient and patient attender and by comparison with the hospital bills.

Methods: The first step was measuring the costs incurred by both the groups in the different categories. Comparisons of the cost were drawn between these groups and the average excess cost was obtained. The second step was to evaluate cost effective strategies that could be implemented. Using the hospital purchase invoices, an approximate cost was obtained. On consultation with the various departmental heads, an approximate daily and monthly use of interventions was obtained. These interventions were regular hand washing, use of gloves, hand disinfections; frequent cleaning of potentially infectious areas, fumigation of the Operation Theatres (OT) and ICUs and an active microbiological surveillance system in order to identify or monitor the adopted strategies.

Analysis: The statistical analysis of the data was carried out by Chi. Square test, Fisher extract test, Odds ratio and Student – ‘t’ test.

Results

The patients in the experiment group and the control group are matched for age, gender as shown in Table 1.The patients in the two groups are matched for the type of surgery undergone as shown in Table 2. The patients in the two groups are matched for ward type as shown in Table 3. The ward type is semi-private ward and general ward.

The number of days of ICU stay in patients

Table 1: Age and sex distribution	Table 2: Comparison of type of surgeries between groups
Table 3: Comparison of ward type between two groups	Table 4: Comparison of ICU stay and ward stay (in days) Results are in Mean ± SD (Min-Max)

affected by SSI is significantly increased in the experiment group as shown in Table 4.

The cost comparison between the two groups of patients is shown in Table 5. The patients in the experiment group have incurred significantly higher costs as compared to the patients in the control group as shown in Figs. 1,2,3 and 4.

The calculation of excess costs borne by the patient is shown in Table 6, and the evaluation of the different prevention strategies adopted for reducing Surgical site infections is shown in Table 7.

Discussion

The most common surgeries that led to SSIs were Gastrectomy (36.4%), Cholecystectomy (15.4%), Prostatectomy (15.2%), Hysterectomy (10.4%) and Appendicectomy (3.4%). The patients in the

Table 5 : Comparison of cost between Experimental and Control group Results are expressed in Mean ± SD

Fig. 1 :Showing the comparison of hospital stay cost.	Fig. 2 :Comparison of medicine bill cost.
Fig. 3 :Comparison of travel cost (travel cost of the attender).	Fig. 4 :Comparison of total cost.

experiment group showed an increase of 7.1 days of ICU stay (P < 0.001) and 11.66 days in the ward stay (P < 0.001). The experiment group showed an increase of 18.56 days and 18.96 days of total hospital stay for patients

Table 6 : Calculation of excess costs incurred when affected by surgical site infections

Table 7 : Calculation and Evaluation of the strategies adopted in reducing surgical site infections

in the semi-private ward and general ward respectively (P < 0.001). Studies by Haley et al, demonstrated that nosocomial infections were a reason of prolonged hospitalization and therefore increased costs adding to the patient’s bill burden.1 Studies by Wakefield et al, showed that patients with nosocomial infections paid higher bills for laboratory investigations and antibiotics.14 Numerous other studies have shown that patients with nosocomial infections had a higher financial burden than those who were not affected.13,15-17 In our study, the patients in the experiment group had to bear an increased burden in the total expense incurred (P < 0.001). The total expense is the costs incurred on the hospital stay and the medicine bill. An average of Rs 13,000.00 was spent in excess by patients for hospital stay and medications as a result of SSIs. Cost effective interventions such as regular hand washing,18,20 skin disinfections,19 use of gloves,20 fumigation of wards and OTs21 and an active microbiological surveillance system21 have proven to be effective in reducing nosocomial infections. Due to cost and time constraints these interventions are often overlooked.22 We evaluated each of these strategies and demonstrated that these interventions are cost effective. Cost effective interventions reduces the incidence of SSIs.23 The above-mentioned strategies are cost effective and if implemented judiciously will reduce the financial burden per patient by around Rs.10300. It is therefore necessary to implement these strategies in an effective manner in order to reduce the incidence of nosocomial infections.

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*Freedom Foundation, Bangalore. **Senior Lecturer, Dept. of Microbiology, Holdsworth Memorial Hospital, Mysore 560007.