Cost-Effectiveness of a Chronic Care Model for Frail Older Adults in Primary Care: Economic Evaluation Alongside a Stepped-Wedge Cluster-Randomized Trial

Abstract

Objectives: To evaluate the cost-effectiveness of the Geriatric Care Model (GCM), an integrated care model for frail older adults based on the Chronic Care Model, with that of usual care.

Design: Economic evaluation alongside a 24-month stepped-wedge cluster-randomized controlled trial.

Setting: Primary care (35 practices) in two regions in the Netherlands.

Participants: Community-dwelling older adults who were frail according to their primary care physicians and the Program on Research for Integrating Services for the Maintenance of Autonomy case-finding tool questionnaire (N = 1,147).

Intervention: The GCM consisted of the following components: a regularly scheduled in-home comprehensive geriatric assessment by a practice nurse followed by a customized care plan, management and training of practice nurses by a geriatric expert team, and coordination of care through community network meetings and multidisciplinary team consultations of individuals with complex care needs.

Measurements: Outcomes were measured every 6 months and included costs from a societal perspective, health-related quality of life (Medical Outcomes Study 12-item Short-Form Survey (SF-12) physical (PCS) and mental component summary (MCS) scales), functional limitations (Katz activities of daily living and instrumental activities of daily living), and quality-adjusted life years based on the EQ-5D.

Results: Multilevel regression models adjusted for time and baseline confounders showed no significant differences in costs ($356, 95% confidence interval = -$488-1,134) and outcomes between intervention and usual care phases. Cost-effectiveness acceptability curves showed that, for the SF-12 PCS and MCS, the probability of the intervention being cost-effective was 0.76 if decision-makers are willing to pay $30,000 per point improvement on the SF-12 scales (range 0-100). For all other outcomes the probability of the intervention being cost-effective was low.

Conclusion: Because the GCM was not cost-effective compared to usual care after 24 months of follow-up, widespread implementation in its current form is not recommended.

Keywords: economic evaluation; frail older adults; integrated care; primary care; stepped-wedge randomized controlled trial.