The cost-effectiveness of the adherence improving self-management strategy (AIMS) in HIV-care: a Markov model

Abstract

Background: Non-adherence to medication is an important cause of poor health and increased health care consumption. The Adherence Improving self-Management Strategy (AIMS) is a nurse-delivered intervention that fits in routine clinical care. Previous trials demonstrated that AIMS is effective but no study has yet estimated the long-term cost-effectiveness of AIMS. The objective of this study was to estimate the cost-effectiveness of AIMS compared with treatment-as-usual (TAU) in HIV-care Methods: A lifetime Markov model was developed using 13 health states (ranging from undetectable viral load and high CD4-cell count, to death). The natural course of illness for HIV-patients receiving TAU was calculated based on a longitudinal dataset from >7.000 patients. Health care consumption, HIV transmission risks, quality of life, and productivity costs were computed for each health state. The effect of AIMS on probability transitions was computed as relative risks, and was derived from a recent multi-centre RCT comparing AIMS with TAU. Incremental cost-effectiveness ratios for a base-case and several sensitivity scenarios were estimated. Findings: The base case and sensitivity scenarios showed that AIMS was dominant to TAU: lower costs and more effective. The incremental quality adjusted life years varied between 0.022 and 0.049, and the incremental costs varied from €-226 to €-1777. These results are robust for changes in important model parameters. Discussion: The current study demonstrates that AIMS is one of the first adherence interventions to be cost-effective and even cost-saving. AIMS should from a clinical and economic perspective be considered for adoption in routine clinical care for HIV.