Risk factors for non-adherence among people with HIV-associated TB in Karnataka, India: A case-control study

Setting Five select districts of Karnataka, India, providing anti-tubercular and antiretroviral therapy (ATT and ART) to people with Human Immunodeficiency Virus (HIV) - associated Tuberculosis (TB) through a single window care approach at the ART centres (seven ART centres and 16 link ART centres). Objectives To determine the factors associated with non-adherence to concurrent therapy. Design We conducted a case-control study involving primary and secondary data collection. Starting January 2019, we consecutively enrolled people on at least three months of ATT until we enrolled 125 cases (non-adherent to concurrent therapy) and 375 controls (adherent to concurrent therapy). Adherence was defined as taking >95% ART doses and >90% ATT doses, every month over the last three months. We performed multivariable logistic regression to identify factors associated with non-adherence. Results The mean age of the cases and control was similar: 39.8 (standard deviation: 8.8) years. The risk factors for non-adherence were status non-disclosure (aOR = 2.06), zidovudine-based ART (aOR = 4.87), >3 side effects (aOR = 6.45), not receiving counselling before ATT initiation (aOR = 5.25) and non-receipt of co-trimoxazole prophylaxis (aOR = 9.90). Conclusion Major determinants for non-adherence were clinical and treatment related factors.