Exploring direction of causation between social support and clinical outcome for HIV-positive adults in the context of highly active antiretroviral therapy.

Social support and its associations with virological outcome were assessed over a 4-year period for 34 adult outpatients living with HIV/AIDS and consistently on highly active antiretroviral therapy (HAART). Clinical variables and perceived availability of social support were measured in three waves (T1, 1997; T2, 1999; T3, 2001). Cross-lagged logistic regression analyses were employed to evaluate the direction of potential causal pathways between social support and clinical status in terms of 'undetectable' viral load. Social support ratings declined moderately overall, with a more pronounced reduction that was of clinical (effect size, 0.82) and statistical significance (p = 0.000) for the subgroup (n = 11; 32%) with final 'detectable' viral load. Evidence suggested causal directionality in which cross-sectional social support and/or improvements in social support over time predicted virological outcome, with better social support associated with greater likelihood of viral load suppression to 'undetectable' level, an outcome achieved for 68% (n = 23) of the sample. In contrast, cross-sectional virological status reflected immunological outcomes but did not predict subsequent ratings of social support or changes in social support ratings. HIV-positive adults consistently taking HAART appeared to experience better clinical benefit if they perceived interpersonal, informational and emotional support to be available, a finding that underscores the importance of social support in relation to treatment outcome for this population.