The mental and physical HRQOL of HIV-infected study participants with opioid dependence improved over time with clinic-based bup/nx. Those continuing to receive bup/nx through all four quarters of follow-up experienced greater gains in both physical and mental HRQOL. Our findings suggest that clinic-based bup/nx maintenance therapy may potentially be effective in ameliorating some of the adverse effects of opioid dependence on HRQOL for HIV-infected populations.
Improvements in composite as well as all component mental HRQOL scores are consistent with findings from studies evaluating the effect of bup/nx treatment on HRQOL among HIV-uninfected patients receiving bup/nx maintenance from specialized addiction treatment centers.27–30
Improvements were also observed for the general health and role physical component scores. Using different quality of life measures, Giacomuzzi, et. al.
and Ponizovsky, et. al.
both reported similar improvements in the physical health sub-domains of their instruments for heroin dependent patients receiving bup/nx maintenance from addiction treatment centers.28, 30
Though observed increases in HRQOL were numerically small in this and other studies, they correspond to potentially dramatic improvements in outcomes. In one study of patients with advanced HIV disease, a 1-point increase in the baseline composite physical or mental HRQOL score corresponded to a 4% decrease in risk of death.16
This suggests the 5-point improvement in composite mental HRQOL observed in our data could potentially reflect improvements associated with decreased mortality.
Improvements in both mental and physical HRQOL in patients with longer retention in clinic-based bup/nx were observed even after adjusting for other significant determinants of HRQOL, suggesting that longer-term prescription of bup/nx maintenance may lead to greater improvements in HRQOL. Clinical trials of bup/nx maintenance vs. short-term bup/nx (supervised opioid withdrawal) demonstrate improved substance abuse treatment outcomes for long-term maintenance.47, 48
Independent improvements in mental HRQOL due to remaining on bup/nx over time were comparable to the observed effect of remaining on HAART in multivariate models. Remaining on HAART over time is associated with decreased depressive symptoms, which may contribute to improved mental HRQOL.31
Although these data cannot address this issue, successful and sustained integration of treatment for HIV and opioid dependence may further benefit patients’ HRQOL by improving convenience, streamlining treatment decisions, increasing engagement in substance abuse and HIV treatment,49
decreasing stigma, and providing a more patient-centered care experience.25
The current study contributes to calls for evaluation of more patient-centered approaches to treatment of substance use disorders50
by directly evaluating HRQOL. U.S. federal agencies are increasing prioritizing patient-rated HRQOL as a key patient-centered outcome.1, 51
Clinic-based bup/nx may be a tool for achieving better patient-centered outcomes for persons with opioid dependence and HIV-infection.25
Baseline patient characteristics, including age, gender, race/ethnicity, homelessness, incarceration, and HIV and drug use severity, were important contributors to mental and physical HRQOL, as has been reported previously in similar populations.6, 19, 52–54
Despite the importance of and adjustment for these factors, persistence on bup/nx throughout four quarters of follow-up was associated with improvements in both mental and physical HRQOL. This is consistent with prior observations that substance use disorders likely eclipse other factors that contribute to HRQOL.52
Our data suggest that addressing opioid dependence with clinic-based bup/nx treatment may mitigate these adverse baseline effects on HRQOL.
Our findings should be interpreted in the context of several potential limitations. First, we were unable to assess participant adherence to bup/nx, potentially biasing our findings toward the null hypothesis. Second, we did not consider substance abuse outcomes (e.g., urine drug screens) which may mediate observed improvements in HRQOL. Third, the number of participants with HRQOL data decreased from baseline through follow-up, potentially resulting in retention bias. An alternative explanation for observed improvements in HRQOL is that participants feeling well were more likely to continue on bup/nx. Fourth, participating HIV clinic providers and staff received substantial training and expert support in implementation of clinic-based bup/nx, and patients benefited from a grant-supported bup/nx clinical coordinator. Observed improvements in HRQOL may not be generalizable to HIV practice settings lacking such resources. Fifth, HIV clinic sites varied in their development of models for bup/nx integration.55
Bup/nx was, however, typically administered by providers using standard bup/nx guidelines.56
Finally, we relied on a single measure, the SF-12, to estimate HRQOL. Though the SF-12 has been well validated in HIV-infected and substance abusing populations previously15, 38–40
, it does not include HIV or opioid dependence specific domains and is susceptible to “floor” effects (i.e., limited sensitivity in measuring lower levels of HRQOL).57–59
Consequently, our results potentially underestimate the true effect of clinic-based bup/nx on HRQOL in this population with highly prevalent physical and mental health disorders.
In summary, the results of this observational cohort study suggest that clinic-based bup/nx maintenance therapy is potentially effective in improving HRQOL for HIV-infected patients with concurrent opioid dependence. Given the adverse impact of opioid dependence on HRQOL and often limited access to treatment, interventions that promote more widespread adoption of clinic-based bup/nx in HIV clinical care settings may contribute to substantial quality of life improvements for this highly vulnerable population.