The morbid conditions included tuberculosis, cancer, diabetes and other medical conditions. We equally excluded the patients who were not willing to participate in the study. Sample Size determination Raosoft® sample size calculator was used to determine the sample Palbociclib clinical trial size31. A sample size of 367 was calculated from the 8000 population of registered patients on ARV drugs using 5% error margin at 95% confidence

interval, assuming 50% of the patients have all the measured outcomes documented in their case files. However, a sample size of 390 patients was used for ease of data analysis. Data abstraction Eligible cases were identified through the main register obtained from the medical record of the APIN clinic. Each patient was assigned an identification number and the find more case file randomly selected using a web-based random sampling method. One of the researchers reviewed each case file, and—using a standard form purposely designed for the study—extracted data on the demographics, concurrent

infections at first presentation and follow-up, co-prescribed drugs, and the ART regimen prescribed. Other important information extracted included the results of routine immunological, virological and haematological investigations at baseline and follow-up. We also extracted information on the relevant clinical signs and symptoms recorded before and after the commencement of ART. Documented adverse drug events were also extracted from the case files. Data initially extracted were corroborated by two other researchers (a clinical pharmacist and a clinical pharmacologist with medical background). There was 85% agreement between the three reviewers using Kappa statistics. The opinion of a fourth reviewer (a clinical pharmacologist with pharmacy background), however, superseded in those areas of disagreement. Prescribed ART regimen The national guidelines for HIV treatment in Nigeria recommended first-line ARV drugs for adults as zidovudine

(AZT) or tenofovir (TDF) with lamivudine (3TC) or emtricitabine (FTC) Idoxuridine and nevirapine (NVP) or efavirenz (EFV) 32. Second-line ARV drugs were recommended when there was therapeutic failure or severe adverse effects to the first line combination. The regimens included AZT-3TC or FTC and TDF or didanosine (ddI) or abacavir (ABC) plus lopinavir/ritonavir (LPV/r). The prescribed ARV drugs that were outside of those recommended by the WHO or national guidelines were considered as others. Adherence and treatment failure Adherence was defined according to the method of Arnsten et al.33 (the percentage of doses taken as prescribed). It was measured by expressing the number of doses taken as a percentage of the total number of doses prescribed. For example if 20 doses were prescribed and 19 doses were taken by a patient, the adherence is 95%. This translates to missing one dose in ten days on a twice daily regimen.