A nested case-control study on relapse predictors among tuberculosis patients treated in Yemen's NTCP

SETTING: The National Tuberculosis (TB) Control Programme in Yemen.

OBJECTIVE: To identify risk factors associated with TB relapse.

METHODS: In a prospective nested case-control study, relapse cases were recruited from a cohort of pulmonary TB patients registered between July 2007 and June 2008. Four controls per case were randomly selected from the list of non-relapse patients. Three forms were used for data collection, which included interviews with the participants and review of their medical cards and TB registers. Multivariate logistic regression analysis was performed to identify independent risk factors for relapse.

RESULTS: A relapse rate of 5.7% was found. Multivariate logistic regression analysis showed that unemployment, smoking, presence of cavitations, weight gain, weight loss, non-adherence during the continuation phase and diabetes were significantly associated with relapse (P < 0.05).

CONCLUSION: Relapse rates can be reduced by ensuring that patients take their treatment regularly and are counselled effectively to stop smoking. Reinforcing the implementation of the DOTS strategy and strengthening the anti-smoking campaigns are important actions. Action to help unemployed patients, including free services and the creation of new job opportunities, should be adopted. Using rifampicin-based regimens in the treatment of cavitary TB and bi-directional screening in TB and diabetes patients are recommended.