Disability and Health Outcomes – From a Cohort of People on Long Term ART

HIV and AIDS remains a major health problem in South Africa even after two decades since the introduction of antiretroviral therapy. Long term survival with HIV is associated with new health related issues and a risk of functional limitation/disability. The aim of this study was to assess the impact and predictors of functional limitation associated with HIV/AIDS among people living with HIV (PLHIV) in South Africa. This study is a cross-sectional survey using a cohort in an urban area in Gauteng province South Africa. Questionnaires that were interview administered were used to collect information on demographics, disability, mental and physical health state, adherence and livelihood. A total of 1044 participants with an average age of 42±12 years, were included in the study and 51.9% of the participants reported functional limitation (WHODAS ≥ 2). These were reported mainly in the participation (40.2%) and mobility domains (38.7%). In addition, adherence to ARV, physical health symptoms and depression were strongly associated with functional limitations/disability. HIV as a chronic disease is associated with functional limitations that are not addressed and pose a risk of long term disability and negative adherence outcomes. Therefore, wellness for people living with HIV/AIDS (PLHIV) needs to include interventions that can prevent and manage disability. DOI : 10.14302/issn.2324-7339.jcrhap-17-1430 Corresponding author: Hellen Myezwa, Department of Physiotherapy,Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193. Phone number: 0117173702


Introduction
Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS) remain key priority health areas in HIV-endemic countries in spite of its thirty year trajectory (1). An estimated 7,000,000 people were living with HIV in South Africa in the year 2015 (2). Due to life saving antiretroviral treatment (ART) more people survive. As a result, the focus of HIV management has shifted in recent years from that of a deadly disease towards managing a chronic condition (3). Managing chronicity requires a move towards a more integrated approach of treatment, care and support that includes rehabilitation in the continuum of care (3)(4)(5). There is similarity in this approach with the systems thinking proposed by Valdiserri in his call for improved focus on demographic and epidemiological data in order to develop high quality systems of care (1). There is very little understanding of the long term health outcomes of living with chronic HIV in Africa and the related services needed to manage associated health needs after long periods on ART (3,4,6). Co morbidities such as TB, cancer and depression have already received some attention (7)(8)(9). We have even less understanding on the long-term effects beyond the investigation of HIV-related conditions and comorbidities.
Recent evidence has suggested that people living with HIV including those on ART experience a diverse set of disabilities (5,(10)(11)(12)(13). The United Nations (UN) Convention on the Rights of Persons with Disabilities (CRPD) has been instrumental in many policy debates including HIV/AIDS. The CRPD offers a tool to protect and promote the rights of people with disability but also those in need of rehabilitation because they are affected by chronicity. The intersection of disability in HIV requires a careful exploration of the impact of the virus and treatment from a multi-systemic perspective. There is however a dearth of empirical information on the intersection of HIV and disability to inform policy and practice. Understanding the scope, types of disabling effects as well as its impact on health outcomes and treatment adherence is crucial to inform management of HIV as a chronic condition (3,6). Existing literature used the international classification of function (ICF) as a lens to understand the relationship between HIV and disability (5,6,10,11,(13)(14)(15). The ICF is a classification system of health components of function and disability.
Studies using this lens indicate a high burden of disability with diverse conditions among people living with HIV and those on ART. However, we have little quantitative evidence from representative cohort studies that can predict better the scope and types of disability in populations living with HIV and its impact on health and ART adherence.
The HIV-Live Study, collaboration between Health, Economics, HIV and AIDS Research Division (HEARD) and University of the Witwatersrand Johannesburg South Africa, sought to address this gap investigating the disabling experiences in three different cohorts and settings. The study investigated the intersection of functional limitation as a proxy for disability, other health outcomes, treatment adherence and livelihood outcomes.
A recent publication reported the results of HIV disability and associations with health outcomes in the first cohort study (HIV-Live) in a semi-rural area in KwaZulu-Natal considered the epicentre of the pandemic in South Africa (6). The results of the second cohort in the urban setting of Gauteng (second highest prevalence in the country) are presented in this paper. The main aim of the study was to investigate the scope and types of functional limitations/disability and the association with health and adherence outcomes with the specific objectives being to determine sociodemographics, livelihood, and medical history, physical, functional and mental health of the cohort.

Methods
A combination of a disability and livelihood framework formed the theoretical basis to investigate the relationship between disability and other outcomes in a cohort of people on ART in South Africa. The overall methodology was developed to include a cross-sectional survey in three cohorts: a semi urban area in KwaZulu-Natal (longitudinal observational study) and two cohorts in the urban area of Gauteng (SA) and United States of America. The cohort in Gauteng was at Helen Joseph Hospital, Themba Lethu HIV clinic where the largest antiretroviral treatment site in the South Africa, operates. Since 2004 over 140,000 patients have been initiated on antiretroviral (ARV) and currently has 8000 patients on treatment.
Each participant was approached as during their routine visit for treatment review and collection of medication. All patients were routinely screened for height, weight, BMI, blood pressure and are screened further by a doctor. Participants had to be attending the outpatient HIV clinic, be between the ages of 18-65 years and have been on ART for six months or longer. Exclusion criteria included participants with any acute opportunistic infection such as active TB or pneumonia and if the patient was pregnant as this would have impacted the disability measure.
A trained research assistant who herself was a patient attending this clinic approached the patients during their visit, explained the purpose of the study and sought initial permission to interview the patient. Three trained research assistants including the principle investigator collected data. All three were trained clinicians and could explain the concepts when misunderstanding arose. The questionnaires were translated into isiZulu and the researchers could use the standardised translated questionnaire where needed. The patient file was accessed after permission was granted by the patient. The length of time on ART and the presence of recent opportunistic infections were extracted as well as the most recent CD4 count. The information extracted was verified with the patient in the interview.
Ethics approval was obtained from the Human and research ethics committee at the University of the Witwatersrand, Johannesburg, South Africa and written informed consent of the participant was obtained.
The estimated sample size for this study was calculated at 1050 with Stata 12.1 with a one sample comparison of proportions (one sample size computation), a 90% power and two-sided test and alpha level of 5% with a hypothesized 55% of the population with disability. Therefore, the estimated sample size was 1050.
The International Classification of Function (ICF) was used as a conceptual framework to define disability. The ICF defines disability as an umbrella term for impairments, activity limitations and participation restrictions. In addition, the interaction between a persons health condition and their context which includes their environmental and personal factors as part of the concept of disability. The central element of disability is therefore the experience of functional or activity limitation on the basis of the interaction between changes in body function (impairment) and unaccommodating environments. As such, scales to investigate function and activity limitations were included in the tool and assessed through the WHODAS 2.0 (18). Importantly, their health condition was also measured using health symptoms commonly experienced by people living with HIV/AIDS PLHIV. Adherence was measured using Mannheimers CASE adherence index (19). Table 1 outlines the instruments used in this study, the variables measured along with the psychometric properties of the instruments and the data analysis approach. Shapiro Wilk test was conducted and the data were non-linear for the main outcome measures (p<0.001). Subsequently Kendall's Tau and Mann Whitney U tests were used to examine the relationship between the dependent and independent variables. While Kendall's Tau is not directly comparable to Pearson's r, as it provides a smaller coefficient, but it can be converted using a formula from Walker (20). Linear regression was used to determine the predictors of the independent variables. All data analysis was done using the IBM SPSS 22.0.

Relationship between functional limitations, health outcomes and socio-demographics
WHO item response theory-scoring and data analysis system was used and the analysis uses overall weighted score of 36, 36 = lowest level of function.
Mental health CESD-10 ( 4 point Likert scale) Ten questions prompting Status as far as depression, level of bother, how fearful, hopeful, happy or lonely one is and the effort required to get going.
The CES D -10 showed good internal consistency reliability with the original CES D 20 (α = 0.88 (24,25) A sum of the scores was taken and a cut off of 16 and above was considered at risk of depression. A converted summary score is calculated with a metric of 0-100 (100 is equal to no symptoms of depression and 0 depicts severe symptoms of depression.) Adherence CASE adherence index Three unique adherence questions combined to form a composite score CASE adherence index showed strong correlation with the three day self-reported adherence (ROC curve >0.86, p<0.001).
A sum of the scores was calculated out of 16, with scores below 11 indicating adherence issues.     Furthermore, the multivariate results in Table 5 shows the health predictors of functional limitation in the six domains, mobility, cognition, self-care, life activity, getting along and participation after adjusting for age, gender, education, marital status, income, exposure to shock, duration of HIV diagnosis and duration on ART.
A one unit increase in mental health and physical health score increased WHODAS score In the specific domains, a unit increase in physical health score increased WHODAS score in the cognition and mobility domains by 0.12 and 0.11 respectively. Also, a one unit decrease in adherence score reduces the WHODAS score by 0.13. In the specific domains, a unit increase in adherence score reduced WHODAS score in the getting along, self-care and life activity domains by 0.28, 0.13 and 0.11 respectively.

Discussion
This study assessed the impact and predictors of HIV-related functional limitations/disability and health outcomes in a cohort of PLHIV on ART for more than six months. In this cohort 51.9% of the participants scored 2 or more on the WHODAS 2.0 using the adjusted measure [14,28,29]. This is higher than in the sister study in KZN [6] and suggest a high prevalene of functional limitations that if not addressed may be a risk of disability. In many studies, disability is described differently and often interchangeably between functional and activity limitation, disability and functioning [5], [28][29][30]. Current measures of disability such as the WHODAS    The physical health state of participants was also associated with disability in the mobility, cognition and participation domains. A poorer state of health is often directly associated with a decreased level of function in the general population [39,40]. In addition, adherence to ARVs has been shown to improve overall health status of PLHIV [36,38]. In this cohort as well as its sister study [6], there is an relationship between adherence and functional limitations/disability. Similarly, in both studies depression correlated with increasing disability and all the subcategories of the WHODAS2.0 scores. A discussion on the implication of depression and disability is beyond scope of this paper, but a matter for further analysis and publication.
Preventing and managing disability is important as it impacts the productivity of a community, function and health related quality of life (HRQOL) [41]. In practice, the management of disability is both multi-sectoral and person centred [41]. The response to needs of PLHIV and AIDS still needs to be outlined better.

Limitations of Study
A limitation in this study was the inclusion criteria which included people on ART for six months or longer. The line of ART therapy was not considered and this could affect the prevalence and the intensity of disability in the study population.

Conclusions
The