[Cost-benefit analysis of the active screening of pulmonary tuberculosis in a recluse population entering prison]. / Análisis coste-beneficio de la búsqueda activa de tuberculosis pulmonar en población reclusa a su ingreso en prisión.

ABSTRACT

BACKGROUND: In spanish prisons, tuberculosis is a serious problem of public health and health authorities don't take it seriously. OBJECTIVE: To prove the efficiency of pulmonary tuberculosis case-finding on arrival at prison in order to get location resources in this activity. METHODS: Cost-benefit analysis of a case-finding program compared with to wait for diagnostic to illness. The sensitivity of test was fixed in 80% and the specificity in 99.99%. The cost was based on market prices. Sensitivity analysis was done in every variables as well as tridimensional analysis in those one of more influence. RESULTS: The case-finding was efficient on prevalences of tuberculosis over 5 per mil. Its efficiency was hardly affected by discount social rates or the sensitivity of diagnostic tests. The prevalence of illness, the cost of diagnostic activities as well as the success of treatment and the specificity of diagnostic tests used had as influence on the efficiency model. The tridimensional analysis proved that the case-finding of pulmonary tuberculosis has efficiency on low prevalences (1 per thousand), provided the number of people cured is a 5% higher than the alternative one and the costs of case-finding less than 1,000 pesetas per subject. CONCLUSIONS: The case-finding pulmonary tuberculosis on arrival at prisons is of high efficiency. In a cost-opportunity situation (location of available resources, penitentiary and extrapenitentiary) the program is very efficacious taking into account the fact of higher prevalence of pulmonary tuberculosis in this people.