Cost-Utility Analysis of Glaucoma Medication Adherence
Ophthalmology, May 2020
Could a personalized team-based approach to glaucoma management—including certified patient coaches—increase notoriously low medication adherence rates? If so, would such interventions be cost-effective from the societal perspective? Newman-Casey et al. modeled costs and time to blindness for patients with optimal versus poor adherence to glaucoma medication. They found that sticking to prescribed treatment regimens could improve quality of life years (QALYs), with just a small increase in lifetime health care costs.
In an earlier study, the authors suggested that a team-based approach might boost patients’ adherence to a treatment plan. For this cost-utility analysis, they used Monte Carlo microsimulations with Markov tracking over one-year increments and a hypothetical cohort of patients. These theoretical patients all had mild glaucoma (less than ‒6 dB of mean deviation), were enrolled at 40 years of age, and continued until they turned 100 or had died. (Probability of death was based on U.S. Census data.)
At enrollment, the cohort’s mean deviation was ‒1.4 ± ‒1.9 dB in the better eye and ‒4.3 ± ‒3.4 dB in the worse eye, reflecting baseline values of the U.K. Glaucoma Treatment Study, which also provided data for estimating glaucoma progression and treatment effect on visual deficits. Adherence rates were derived from four-year U.S. claims data, and the probability of disease worsening each year (accumulated ‒0.8 dB loss) was based on the Glaucoma Laser Trial and the Tube Versus Trabeculectomy studies. Direct and indirect health costs were assessed at each “stage” of disease, as were societal costs from vision loss. Main outcomes were cost and QALYs of medication adherence.
After 10,000 iterations per strategy, the quickest progressions to blindness in one eye for consistently adherent and nonadherent patients were 23 and 19 years, respectively. Total health care costs (≤60 years after diagnosis) were $62,782 for adherent patients and $52,722 for those who did not adhere to their medication protocols. During the same period, nonadherent patients lost a mean of 0.34 QALY relative to adherent patients, yielding a cost-effectiveness ratio of $29,600 per QALY gained.
According to the authors, assuming a willingness to pay $50,000 per QALY gained, self-management counseling services that improve medication adherence would be highly cost-effective. They noted that more studies using national estimates of glaucoma are needed. (Also see related commentary by Florent Aptel, MD, in the same issue.)
The original article can be found here.