Assessment of factors influencing adherence to antiretroviral therapy at Nyeri provincial hospital in Central Kenya.

The Nyeri Provincial General Hospital (PGH) was one of the five pilot sites at which the Government of Kenya started providing antiretroviral therapy (ART) to HIV-infected patients in 2003. At this hospital, as in the other pilot sites, there was an increasing number of patients requiring a switch from first line to second line ART drug regimens due to treatment failure. There was little information available on levels of adherence to ART as well as the factors that influence adherence among patients to guide adherence promotion strategies and thus reduce the incidence of virologic and treatment failure. The objective of this study was to assess factors that influence adherence to ART at Nyeri PGH. The study was retrospective and cross-sectional. Two hundred and twenty nine patients were selected from a total of 705 patients who had been active on ART for at least one year and who were on solid drug dosage forms. Stratified random sampling was used to obtain the same relative proportions of adults, paediatrics, male and female respondents in the sample population as in the study population. Semi-structured interview schedules were used to obtain demographic information and patients’ views on various dimensions of ART services at the hospital. Pill count data of patients collected over a period covering 3 clinic appointments was used to determine the percentage adherence levels of the patients to ART. For 13% of the patients for whom pill count data was not available, pharmacy refill dates were used to estimate adherence levels. Univariate analysis of various factors was undertaken to examine the odds of adherence and non-adherence to ART with respect to the various factors. Response values and categories were assigned to questions. Patient responses on ART services at the hospital were grouped into four categories: ART Acceptability, ART Accessibility, ART Affordability and ART Availability. The response scores were aggregated per statement and averaged to get mean scores for each category. The mean scores for each category of questions were subjected to correlation analysis to check for the influence of patients’ views on their adherence level to ART. The mean adherence rate for all the patients was 92.7% ± 8.5%. The number of patients exhibiting optimal adherence (greater than 95%) to ART was 125, representing 55% of the total patients interviewed. 197 (86%) of the patients exhibited greater than 85% adherence to ART. Only 11 (5%) of the patients sampled had less than 75% adherence to ART. Being busy with household chores and job-related tasks (39%) as well as travelling (21%) were cited by the respondents as the most important factors affecting adherence. Occupation of patient was found to influence adherence with employed patients exhibiting a higher rate of non-optimal adherence (Odds Ratio of non-optimal adherence: 2.64, 95% CI, 1.3863 to 4.8708, P < 0.005). Age, gender, level of education, marital status and knowledge of HIV disease were not found to significantly affect adherence. On correlation analysis, patients’ views on ART availability and ART acceptability were significantly correlated with percentage adherence to ART (Spearman’s r = −0.157, P < 0.05 and Spearman’s r = 0.255, P < 0.01 respectively). Based on the adherence levels established in this study showing that about 14% of the study population was at an elevated risk of virologic failure, there is urgent need to institute measures to identify those patients with non-optimal adherence to ART and work out strategies to improve their adherence. Particular effort should be made to prepare practical medication taking plans for employed patients initiating ART therapy.