Incidence and factors associated with unfavourable treatment outcome among patients with rifampicin-resistant pulmonary tuberculosis in Yaoundé, Cameroon

INTRODUCTION: in Cameroon patients with multidrug/rifampicin resistant pulmonary tuberculosis (MDR/RR-PTB) are treated with a 9-11 month standardised shorter treatment regimen. Despite its effectiveness, factors associated with the occurrence of an unfavourable treatment outcome in this group of patients are not known. Determine the incidence and identify factors associated with an unfavourable treatment outcome among patients with rifampicin resistant pulmonary tuberculosis (RR-PTB) in Yaoundé. METHODS: we conducted a retrospective record review of all consecutive patients with bacteriologically confirmed RR-PTB followed up at the specialised MDR/RR-TB treatment centre of the Jamot Hospital in Yaoundé (JHY) from January 2013 to November 2019. A patient was classified as having an unfavourable outcome if he/she had treatment failure, died or was lost to follow-up during the course of treatment. RESULTS: a total of 242 RR-PTB patients with a mean age of 35.59 ± 12.02 years including 144 (59.5%) males were registered. Forty-nine (49) of the 242 patients had an unfavourable treatment outcome giving a cumulative incidence of 20.20% (95% confidence interval (95% CI): 15.40-25.90%). Multivariable analysis revealed that patients with an unfavourable outcome were more likely to be males (odds ratio (OR): 2.94; 95% CI: 1.24-7.00, p= 0.015), HIV infected (OR: 2.67; 95% CI: 1.17-6.06, p = 0.019), and have a baseline haemoglobin level ≤ 10g/dl (OR: 2.87; 95% CI: 1.25-6.58, p = 0.013). CONCLUSION: the rate of an unfavourable treatment outcome among patients with RR-PTB at the specialised MDR/RR-TB treatment centre of the JHY is relatively high. The male sex, HIV infection and moderate to severe anaemia are independent factors associated with an unfavourable treatment outcome.