Cost-effectiveness analysis of integrated care for people with HIV, chronic mental illness and substance abuse disorders.

BACKGROUND: Triply diagnosed patients, who live with HIV and diagnosed mental health and substance abuse disorders, account for at least 13% of all HIV patients. This vulnerable population has substantial gaps in their care, attributable in part to the need for treatment for three illnesses from three types of providers.

AIMS OF THE STUDY: The HIV/AIDS Treatment Adherence, Health Outcomes and Cost study (HIV Cost Study) sought to evaluate the cost-effectiveness of integrated HIV primary care, mental health, and substance abuse services among triply diagnosed patients. The analysis was conducted from a health sector budget perspective.

METHODS: Patients from four sites were randomly assigned to intervention group (n=232) or control group (n=199) that received care-as-usual. Health service costs were measured at baseline and three, six, nine and 12 months and included hospital stays, emergency room visits, outpatient visits, residential treatment, formal long-term care, case management, and both prescribed and over-the-counter medications. Costs for each service were the product of self-reported data on utilization and unit costs based on national data (2002 dollars). Quality of life was measured at baseline and six and 12 months using the SF-6D, as well as the SF-36 physical composite score (PCS) and mental composite score (MCS).

RESULTS: During the 12 months of the trial, total average monthly cost of health services for the intervention group decreased from USD 3235 to USD 3052 and for the control group decreased from USD 3556 to USD 3271, but the decreases were not significant. For both groups, the percentage attributable to hospital care decreased significantly. There were no significant differences in annual cost of health services, SF-6D, PCS or MCS between the intervention and control group.

IMPLICATIONS FOR HEALTH CARE PROVISION AND USE: The results of this randomized controlled trial did not demonstrate that the integrated interventions significantly affected the health service costs or quality of life of triply diagnosed patients. Professionals could pursue coordination or integration of care guided by the evidence that it does not increase the cost of care. The results do not however, provide an imperative to introduce multi-disciplinary care teams, adherence counseling, or personalized nursing services as implemented in this study.

IMPLICATIONS FOR HEALTH POLICIES: There is not enough evidence to either limit continued exploration of integration of care for triply diagnosed patients or adopt policies to encourage it, such as financial reimbursement, grants regulation or licensing.

IMPLICATIONS FOR FURTHER RESEARCH: Future trials with interventions with lower baseline levels of integration, longer duration and larger sample sizes may show improvement or slow the decline in quality of life. Future researchers should collect comprehensive cost data, because significant decreases in the cost of hospital care did not necessarily lead to significant decreases in the total cost of health services.