Cost savings from an mHealth tool for improving medication adherence.

Objective: To determine the health care cost savings from the Wellth app, a mobile health intervention that uses financial incentives to increase medication adherence.

Study Design: An observational study of members in one of Arizona's Medicaid managed care plans, part of Arizona Health Care Cost Containment System (AHCCCS), using the Wellth app from March 28, 2020, to January 12, 2021. One-to-one matching was used to identify comparable nonparticipants, and a difference-in-differences approach was used to estimate the impact of the Wellth intervention on outcomes defined over the 9 months before and after using Wellth.

Methods: An AHCCCS managed care health plan provided claims data that contained drug prescription, health care utilization, and health care cost information for all participants, and Wellth provided app usage data and contextual information about the Wellth intervention.

Results: On average, the Wellth intervention increased medication adherence by 5.0 percentage points (95% CI, 2.9-7.1; P = .008) and reduced emergency department (-0.02; 95% CI, -0.03 to -0.01; P = .002), inpatient (-0.04; 95% CI, -0.06 to -0.02; P = .001), and mental health clinic (-0.06; 95% CI, -0.10 to -0.01; P = .013) visits relative to nonparticipants over 9 months. Short-term reductions in utilization had an estimated mean cost savings over 9 months of $88.15 (95% CI, $31.07-$136.40), with greater reductions for those with chronic obstructive pulmonary disease, schizophrenia, or major depression.

Conclusions:  Given the relatively low cost of the Wellth intervention, our findings provide preliminary evidence of cost savings from implementing Wellth among adults with several common chronic conditions.