The Poor Survival among Pulmonary Tuberculosis Patients in Chiapas, Mexico: The Case of Los Altos Region

Objective. To analyse survival in patients with pulmonary tuberculosis (PTB) and factors associated with such survival. Design. Study of a cohort of patients aged over 14 years diagnosed with PTB from January 1, 1998 to July 31, 2005. During 2004–2006 a home visit was made to each patient and, during 2008-2009, they were visited again. During these visits a follow-up interview was administered; when the patient had died, a verbal autopsy was conducted with family members. Statistical analysis consisted of survival tests, Kaplan-Meier log-rank test and Cox regression. Results. Of 305 studied patients, 68 had died due to PTB by the time of the first evaluation, 237 were followed-up for a second evaluation, and 10 of them had died of PTB. According to the Cox regression, age (over 45 years) and treatment duration (under six months) were associated with a poorer survival. When treatment duration was excluded, the association between poorer survival with age persisted, whereas with having been treated via DOTS strategy, was barely significant. Conclusions. In the studied area it is necessary that patients receive a complete treatment scheme, and to give priority to patients aged over 45 years. 1. Introduction Tuberculosis (TB) continues to be one of the leading causes of disease, disability, and death. Seventy-five percent of people with TB belong to the economically active age group (15–54 years) and 95% of the cases and 99% of deaths occur in developing countries [1]. The incidence rate of TB in Mexico in 2007 was 20/100,000 and the death rate was 2.4/100,000 [2]. Nevertheless, given the socioeconomic conditions in the country such as high rurality, high levels of poverty, and shortage of health resources in marginalized areas, both figures might be higher. Chiapas is among the Mexican states with the highest indices of poverty [3]. This state shows one of the highest proportions of rural and indigenous population, has the lowest human development index of the whole country [3], has the lowest per capita availability of health resources [4, 5], and has the highest rates of prevalence and mortality due to TB [6]. This situation is even worse in rural indigenous populations of Chiapas, like Los Altos region, where in many communities access to basic services turns out to be more a privilege than a right. In such circumstances, control and anti-TB treatment of TB patients via the directly observed treatment short-course (DOTS) strategy is very difficult. Therefore the results of this situation are high levels of under-diagnosis and of treatment defaulting,