Analysis of loss to follow up in 4,099 multidrug-resistant pulmonary tuberculosis patients

Loss-to-follow-up (LFU) of two or more consecutive months contributes to the poor levels of treatment success in multidrug-resistant tuberculosis (MDR-TB) reported by TB programmes. We explored the timing of when LFU occurs by month of MDR-TB treatment and identified patient-level risk factors associated with LFU. We analysed a dataset of individual MDR-TB patient data (4099 patients from 22 countries). We used Kaplan-Meier survival curves to plot time to LFU and a Cox proportional hazards model to explore the association of potential risk factors with LFU. One-sixth (n=702) of patients were recorded as LFU. Median time to LFU was 7 months (IQR=3–11). The majority of LFU occurred in the initial phase of treatment (75% in the first 11 months). Major risk factors associated with LFU were: age 36–50 years (Hazard Ratio (HR) 1.3; 95% CI 1.0, 1.6, p=0.04) compared with age 0–25 yrs, being HIV+(HR 1.8; 95% CI 1.2, 2.7, p Both patient- and regimen-related factors were associated with LFU which may guide interventions to improve treatment adherence, particularly in the first 11 months.