HIV-positive people report that the quality of their lives is better when they’re on treatment, compared with when they’re taking a drug holiday, according to new data from a sub-study of a large international clinical trial published in the February 1 issue of the Journal of Acquired Immune Deficiency Syndromes (JAIDS).

The larger trial, called the Strategies for Management of Antiretroviral Therapy (SMART) study, originally enrolled 5,472 patients in 33 countries. It was designed to determine whether people who interrupt antiretroviral therapy when they are clinically healthy—remaining off therapy until their CD4 count decreases significantly or their viral load increases significantly—would remain as medically stable as people who stayed on continuous treatment, with fewer side effects. Instead, the SMART study was stopped early because people who interrupted antiretroviral therapy were far more likely to develop serious health problems than people who remained on continuous therapy.

In order to assess the impact of continuous versus interrupted treatment on participants’ quality of life (QOL), U.S. patients who enrolled in the SMART study were offered the opportunity to simultaneously enroll in a sub-study, the results of which are reported in the current issue of JAIDS.

William Burman, MD, of the University of Colorado Health Sciences Center in Denver, and his colleagues enrolled 1,225 participants in the sub-study. QOL was assessed at baseline—when people first entered the study—and then 12 and 36 months later. Surveys and interviews were used to assess volunteers’ QOL. Measures of QOL included people’s perceptions of their general health, physical functioning, level of pain, mental health, energy and other factors. Researchers also assessed the prevalence of common side effects like nausea, diarrhea and fatigue. The participants were similar in all regards at baseline and 50 percent rated their health as “very good” or “excellent.”

On some measures of QOL, such as mental health and pain levels, participants on continuous therapy were statistically equivalent to participants who interrupted therapy. However, on all measures where there was a statistically significant difference—meaning the difference was too great to have occurred by chance—participants on continuous therapy faired better than participants who interrupted therapy. Those measures included self-perceptions of general health, physical functioning and physical energy. This remained true even when researchers removed patients who had developed serious health problems from the analysis. Patients who interrupted therapy were also more likely to experience side effects than people who remained on continuous therapy.

Burman and his team acknowledge that the results are relevant only for treatment interruptions of the type used in the SMART study and not for other treatment-interruption strategies. They also point out, however, that the results of the sub-study remain significant through different types of analysis.