Factors associated with failure of initial anti-tuberculosis treatment at the Diagnostic and Treatment Centre of Kabinda General Referral Hospital, Kinshasa, DRC

Background Tuberculosis remains a major public health problem worldwide, particularly in sub-Saharan Africa. Despite the availability of effective anti-tuberculosis treatment, unfavourable outcomes persist, including treatment failure. Treatment failure threatens tuberculosis control because affected patients may remain infectious and are at increased risk of developing drug-resistant tuberculosis. This study aimed to identify factors associated with failure of initial anti-tuberculosis treatment at the Diagnostic and Treatment Centre of Kabinda General Referral Hospital in Kinshasa, Democratic Republic of the Congo. Methods A case-control study was conducted among tuberculosis patients treated at the Diagnostic and Treatment Centre of Kabinda General Referral Hospital between 1 January 2016 and 31 December 2022. Cases were tuberculosis patients aged 18 years or older who experienced failure of initial anti-tuberculosis treatment. Controls were tuberculosis patients aged 18 years or older who were declared cured or completed treatment successfully. A total of 178 participants were included: 59 cases and 119 controls. Data were collected from treatment registers, laboratory registers, individual treatment records, and participant interviews. Sociodemographic, economic, behavioural, clinical, and biological variables were analysed. Logistic regression was used to identify factors associated with treatment failure. Results In multivariable analysis, five factors were independently associated with failure of initial anti-tuberculosis treatment: consuming one meal or less per day (adjusted odds ratio [aOR] 9.76, 95% confidence interval [CI] 2.24–42.63), irregular medication intake (aOR 5.68, 95% CI 1.25–25.84), non-adherence to directly observed treatment during the first two months of treatment (aOR 10.21, 95% CI 2.51–41.67), history of tuberculosis (aOR 11.71, 95% CI 2.57–53.44), and positive sputum smear at the second-month treatment follow-up (aOR 21.68, 95% CI 4.39–107.04). Conclusions Failure of initial anti-tuberculosis treatment in this setting was associated with socioeconomic vulnerability, poor treatment adherence, previous tuberculosis, and persistent sputum smear positivity after two months of treatment. Strengthening nutritional and socioeconomic support, improving adherence counselling, reinforcing directly observed treatment, and ensuring early follow-up of patients with persistent smear positivity could reduce treatment failure and help prevent drug-resistant tuberculosis.