HIV-positive individuals in the SMART study who were in the treatment conservation arm experienced a significant decline in quality of life as the study progressed, according to data presented to the Sixteenth International AIDS Conference in Toronto on August 17th.
The SMART study was the largest HIV clinical trial ever, involving 5,472 patients in several countries. Patients were randomised to either a treatment conservation arm (discontinue antiretroviral therapy once their CD4 cell count reached 350 cells/mm3, and recommencing therapy when it fell to 250 cells/mm3), or to continue to take their anti-HIV therapy without interruption. The study was terminated early on safety grounds after it was established that patients in the treatment interruption arm were significantly more likely to experience disease progression or death.
It had been theorised that interrupting anti-HIV therapy would improve the quality of life of individuals in the treatment conservation arm by reducing their exposure to potentially toxic antiretroviral drugs. To assess the effect of treatment interruption versus continuous treatment on self-reported quality of life, investigators conducted a sub-study involving 1,225 patients enrolled at the 64 US clinics participating in the SMART study.
At baseline, and then at months four, eight and twelve and annually thereafter, patients completed quality-of-life assessments, designed to determine their perceived physical and mental health.
Median CD4 cell count at baseline was 575 cells/mm3, three-quarters of the patients were taking potent HIV therapy, and 25% were women.
At the start of the study, the mean current state of health score was 75 out of 100, and 50% of individuals rated their health as very good or excellent. Individuals were then followed up for a mean of 2.4 years.
During this period, current health and general health perceptions declined significantly in the treatment conservation arm, but increased amongst patients randomised to take their HIV therapy all the time. (p = 0.02).
Patients interrupting their treatment scored their physical health status significantly lower than that of patients taking continuous treatment (p = 0.005), and reported having lower levels of energy (p = 0.05). In addition, individuals in the drug conservation arm experienced greater levels of pain than patients randomised to take continuous therapy (p < 0.001), as well as having poorer mental health (p < 0.001) and lower social functioning (p < 0.001).
The investigators therefore concluded that the episodic use of HIV therapy did not improve quality of life.
Burman W et al. The effect of episodic CD4-guided antiretroviral therapy on quality of life: results of the quality of life substudy of SMART. Sixteenth International AIDS Conference, Toronto, abstract THPE0145, 2006.