Rate and risk factors of recurrent tuberculosis in Yemen: a 5-year prospective study

Background: Tuberculosis is a major public health concern in Yemen. Recurrence of tuberculosis complicates the situation further, and has severe negative economic and health consequences. This study estimated the tuberculosis recurrence rate during a 5-year follow-up period, and identified risk factors associated with recurrence. Methods: This was a prospective study with a 5-year follow-up period conducted at health centres with tuberculosis units in ten governorates. Participants were prospectively enrolled in the study from July 2007 to June 2008, with the last patient completing treatment on March 15, 2009. Results: A cohort of 814 patients with pulmonary tuberculosis completed treatment and was followed-up for five years. During the follow-up, 3.4% (n = 28) died and 4.3% (n = 35) were lost to the study, giving a final cohort of 751 patients. The mean age +/- standard deviation was 32 +/- 13 years. Males represented 57.6% of the subjects. The overall recurrence rate of tuberculosis was 9.5% (71/751), with significant variation between subgroups of patients (range = 7-25.8%). The highest recurrence rates were found in patients with diabetes (25.8%, p < .001), non-adherent patients (22%, p < .001), smokers (16.1%, p = .010), patients with cavitary lung disease (14.4%, p = .004), patients with weight gain <= 5% during the intensive phase (13.3%, p < .001) and unemployed patients (11.9%, p = .017). In multivariate logistic regression analysis, these risk factors were independently associated with recurrent tuberculosis: diabetes (adjusted odds ratio, aOR 3.78, 95% confidence interval, CI 1.84-7.80), non-adherence (aOR 3.22, 95% CI 1.76-5.87), weight gain <= 5% (aOR 2.51, 95% CI 1.39-4.55), smoking (aOR 2.18, 95% CI 1.07-4.47), presence of lung cavitation (aOR 2.01, 95% CI 1.16-3.46), and unemployment (aOR 2.15, 95% CI 1.16-4.01). Conclusion: The recurrence rate of tuberculosis in Yemen was high. The presence of risk factors in newly diagnosed patients should alert healthcare professionals. As most of risk factors were modifiable, the World Health Organisation model of patient-centered care in tuberculosis treatment should be promoted in all tuberculosis centres in the country.