Incidence, time and determinants of tuberculosis treatment default in Yaounde, Cameroon: a retrospective hospital register-based cohort study

OBJECTIVES: High rates of antituberculosis treatment discontinuation have been reported in some areas of Africa. The aim of this study was to determine the rate, time to and determinants of antituberculosis treatment default in Yaounde. DESIGN: This was a retrospective cohort study based on hospital registers. Tuberculosis treatment default or antituberculosis treatment discontinuation was defined as any interruption of treatment for at least 2 months following treatment initiation. Sociodemographic and clinical predictors of treatment discontinuation were investigated with the use of Cox regressions models. SETTING: This study was carried out in the tuberculosis diagnosis and treatment centre at Yaounde Jamot Hospital, which serves as a referral centre for tuberculosis and respiratory diseases for the capital city of Cameroon (Yaounde) and surrounding areas. PARTICIPANTS: All (1688) patients started on antituberculosis treatment at the centre between January and December 2009 were enrolled. Outcome measures were antituberculosis treatment default and time to treatment default. RESULTS: Of the 1688 included patients, 337 (20%) defaulted from treatment, 86 (5.1%) died, treatment failed in 6 (0.4%) and 104 (6.2%) were transferred. Therefore, treatment was successfully completed in 1154 (68.4%) patients. Median duration to treatment discontinuation was 90 days (IQR 30–150), and 62% of treatment discontinuation occurred during the continuation phase. Hospitalisation during the intensive phase (adjusted HR 0.69; 95% CI 0.54 to 0.89) and non-consenting for HIV screening (1.65; 1.24 to 2.21) were the main determinants of defaulting from treatment in multivariable analysis. CONCLUSIONS: The default incidence rate is relatively high in this centre and treatment discontinuation occurs frequently during the continuation phase of treatment. Action is needed to improve adherence to treatment when received on an ambulatory basis, to clarify the association between HIV testing and antituberculosis treatment default, and to identify other potential determinants of treatment discontinuation in this setting.