Gaceta Sanitaria (Jun 2003)
Incremento de costes atribuible a la infección quirúrgica de la apendicectomía y colectomía Increase in costs attributable to surgical infection after appendicectomy and colectomy
Abstract
Objetivo: Determinar los costes mediante la medición directa, caso a caso, de la infección del sitio quirúrgico en la apendicectomía y la colectomía. Métodos: Diseño: estudio de casos y controles con base poblacional; los casos fueron todos los pacientes diagnosticados de infección de sitio quirúrgico tras apendicectomía o colectomía en SCIAS-Hospital de Barcelona, y los controles una muestra seleccionada aleatoriamente entre los pacientes no infectados que reunían características comunes para el apareamiento. Período de estudio: del 1 de enero de 1998 al 31 de diciembre de 1999. Tipos de apareamiento: a) individual de pacientes agrupados según el diagnóstico principal, el procedimiento quirúrgico principal, la edad y el sexo, y b) individual de pacientes agrupados según el diagnóstico principal, la edad y el sexo, pero utilizando además para la selección de los controles el diagnóstico secundario. Fuentes de información: sistema informático de registros e historias clínicas en soporte electrónico, incluyendo los costes registrados en tiempo real. Contabilidad analítica: programa ADS plus®, que calculó costes reales (paciente por paciente) a partir de datos como el consumo de farmacia, el material sanitario, las pruebas adicionales de diagnóstico y las estancias generadas. Los costes estructurales se imputaron en la matriz de costes a partir del cálculo contable y su impacto en los costes directos. Se consideró coste atribuible a la infección al coste incremental o adicional resultante de la diferencia entre casos y controles. Análisis estadístico: los cálculos estadísticos se realizaron mediante el paquete estadístico SPSS, versión 9.0. Se utilizaron pruebas no paramétricas teniendo en cuenta el tamaño de la muestra. Se aplicó el test de Wilcoxon para variables continuas con el fin de comparar la edad, la duración de las intervenciones quirúrgicas, la estancia hospitalaria y los costes. Los resultados se expresaron como media aritmética. Se consideró un nivel de significación estadística un valor de p Objective: To determine the costs, with the help of direct case to case measurement, of the surgical site infection in apendicectomy and colectomy. Methods: Design: cases and controls study, population-based, in which the cases were all the patients diagnosed of surgical site infection after apendicectomy or colectomy in SCIAS- Hospital de Barcelona, and the controls were a random sample of noninfected patients that presented common characteristics for matching purposes. Study period: from January 1, 1998, to December 31, 1999. Types of matching: a) individual, patients grouped according to main diagnosis, main surgical procedure, age and gender, and b) patients grouped according to main diagnosis, main surgical procedure, age and gender using in addition, as controls criteria, the number of secondary diagnoses. Data sources: computer system with all the registries and clinical histories in electronic support, including the costs registered in real time. Analytical Accounting: ADS plus® program that calculated the real costs (patient to patient) extracted from real data, such as drugs consumption, medical supplies, additional diagnosis tests and generated stays. The structural costs were imputed in the matrix of costs from the countable calculation and its impact on the direct costs. The cost attributable to the infection was calculated as the additional cost resultant from the difference between cases and controls. Statistical analysis: the statistical calculations were made by means of the statistical package SPSS, version 9.0. Nonparametric tests were used considering the sample size. The test of Wilcoxon for continuous variables, with the purpose of comparing age, operations length, hospital stay and costs, was applied. The results were expressed as arithmetic mean. A level of statistical meaning of p < 0.01 was considered. Results: The first matching included 23 cases and 23 controls for patients operated on apendicectomy and 20 cases and 20 controls for those operated on colectomy. In matching 2, the sample consisted on 17 pairs of cases and controls on apendicectomy and 14 pairs of cases and controls on colectomy. The infection increased the average length of stay between 7.7 days (matching 1) and 7.3 days (matching 2) in cases of infected apendicectomy and between 17.6 days (matching 1) and 15.4 days (matching 2) in cases of infected colectomy. The patients with apendicectomy infection presented an average cost three times higher than the ones not infected, both in matching 1 (2,998.60 versus 941.89 €, respectively; p < 0.0001) and in matching 2 (2,751.70 versus 870.81 €, respectively; p < 0.0001). Similar findings were observed in colectomy both in matching 1 (10,705.34 versus 2,600.55 €, respectively; p < 0.0001) and in matching 2 (9,081.12 versus 2,621.39 €, respectively; p < 0.0001). The average cost of surgical site infection oscillated between 2,056.71 € (matching 1) and 1,880.89 € (matching 2) in apendicectomy and between 8,140.79 € (matching 1) and 6,405.65 € (matching 2) in colectomy. Conclusions: Under the study conditions, the infection of surgical site determines the prolongation of the hospital stay in more than one week in apendicectomy and in more than two in colectomy, with an increase higher than 300% in the total direct cost.
