A case control study to identify factors that may influence anti-retroviral treatment adherence

Abstract

This study was carried out in order to determine factors that may influence anti-retroviral therapy (ART) adherence. The main objective was to identify factors that can be used to predict adherence in patients taking ARVs. Specific objectives were to identify associations between patients' knowledge, beliefs, socio-economic status and disclosure and adherence. This was a case-control study carried out at Chreso Ministries ART and VCT Centre in Lusaka, Zambia. A total of 304 respondents who had been on ART for not less than 6 months were studied between may 2006 and September 2006. Tests of associations using the Chi-squared test or the Fisher's Exact test were done using Epi Info. SPSS's logistic regression was used to determine predictability.Age and education yielded insignificant differences of adherence among different age groups (X^ 1.27; p value 0.259) and among different education levels (X^ 4.51; p value 0.211). Results on knowledge showed that there was no association between knowledge and adherence (p value 0.817). Respondents who believed in both ARVs and God were 1.96 times (95% CI 1.06 to 3.69) more likely to adhere to treatment than those that believed in God alone. The association between beliefs regarding whether ARVs have potency to restore life or not and adherence was not statistically significant (P value of 1.000). We also wanted to determine whether an association existed between disclosure of one's HIV status and adherence. The results of the test of significance were X^ 0.93 and p value of 0.335 indicating that there was no significant association between disclosure and adherence. Most of the respondents disclosed their status in both groups (92.3% among persons among the cases [adherent clients] and 95.8% among the controls [non adherent clients).The association between income and adherence was not statistically significant (p value = 0.905). Employment status yielded no significant results (p value=0.161). However, there was a significant association between presence of another chronic illness (that demands for more pills per day) and adherence (X^3.9; p value=0.048). Respondents with a chronic illness were 43% (OR=0.57, 95% CI 0.33 to 1.00) less likely to adhere compared to respondents who had no chronic illness. Then we found no significant association between those that had taken alcohol in the last 3 months and adherence (OR=0.82; P value=0.617; and at 95% CI 0.34 to 1.56)Most importantly in this research, we were interested in predicting adherence using the record captured variables of employment status at enrolment, income level at enrolment, disclosure status at enrolment and timing of treatment inception. The probabilities of predicting adherence were employment status 0.375; income 0.383, disclosure 0.369 and timing of treatment inception 0.292. The probabilities of predicting adherence using any of these variables were found to be too small to be used for prediction and therefore we concluded that there is need to continue researching for good predictors of adherence.