The Association between Asymptomatic and Mild Neurocognitive Impairment and Adherence to Antiretroviral Therapy amongst people living with HIV
Date of Award
Master of Medicine (MMed)
Professor Gerald Yonga
Dr Reena Shah
Dr Peter Mativo
Internal Medicine (East Africa)
Background: HIV disease is associated with neurocognitive impairment which is one of the neurological complications of the viral infection. The spectrum of HIV Associated neurocognitive impairment has significantly changed since the advent of ART. The inclusion of the asymptomatic but cognitively impaired population of patients has changed the dynamics of this population, and requires further research to identify the impact it has on the progression of the disease as well as on any other aspects. Poor adherence to ART is one of the main causes of treatment failure and studies done previously point towards the milder forms of Neurocognitive Impairment as being a cause of poor adherence, among other aspects.
Primary Objective: To assess the association between the milder forms of neurocognitive impairment and adherence to ART.
Methods: The study was a cross-sectional survey, with consecutive sampling, with a total sample size of 218 patients. An association was sought between cognitive status and adherence as measured by objective means, self-reported means and last viral load value as a surrogate marker. The study utilised quantitative primary data on pre-defined baseline characteristics, neurocognitive assessment by MOCA, instrumental activities of daily living by Lawton score and objective and subjective adherence measures by medication possession ratio (MPR) and simplified medication adherence questionnaire (SMAQ) respectively. Univariate and bivariate analysis was conducted to determine the strengths of association between various predictor and the outcome variables.
Results: A final sample size of 218 was selected out of all those eligible (500 patients). All study participants underwent a neurocognitive assessment, which revealed 69% minor neurocognitive impairment while 31% had no neurocognitive impairment. No patient was identified with HIV associated dementia on screening. Secondly, all study participants underwent adherence assessment which revealed optimal adherent rates of 66% and 77% by objective (by MPR) and subjective (SMAQ) measures respectively. There were no statistically significant differences in the baseline characteristics (age, gender, education, marital status, living arrangements, employment status, level of income) between the group of participants with cognitive impairment and those without impairment (p-value > 0.05). Similarly, when the same group were compared on characteristics related to their HIV diagnosis and treatment, no statistically significant differences were observed (p-value > 0.05).
Discussion: Even though the rate of cognitive impairment in this study was high, it corresponds to some of the studies earlier carried out (CHARTER study = 53%), the majority of which were asymptomatic and Mild Cognitive Disorders, while only 2% had HIV Associated Dementia. It is however important to note that the MOCA screening tool, initially designed to screen for minor cognitive impairment, has had various cut off scores in different studies. Finally, whereas MOCA is only a screening tool, confirmation of neurocognitive impairment requires a battery of tests administered over a period of time which is not possible in routine clinic care or the settings of this study. Adherence rates observed in this study approximate those observed in other settings for patients on treatment with ART.
Conclusions: Cognitive impairment is prevalent in the population studied. However, despite lack of association between adherence to medication and cognitive impairment, the relevance of these finding needs to be assessed.
Recommendations: There is need to assess for early forms of cognitive impairment in patients on treatment with ART using culturally sanctioned assessment tools to enable identification. Further studies with participants from diverse settings need to be done to enable validation of the tools used for this purpose as well as to determine the relevance of this finding in HIV positive individuals.
Awori, V. M. (2016). The Association between Asymptomatic and Mild Neurocognitive Impairment and Adherence to Antiretroviral Therapy amongst people living with HIV (Unpublished master's dissertation). Aga Khan University, East Africa.