From Bruce Stuart et al.:
Similar to previous studies,[*] we found that high adherence to [angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, oral antidiabetic drugs], and statins by Medicare beneficiaries with diabetes was associated with lower medical costs and higher drug costs. In all cases, the savings on the medical side more than compensated for greater drug spending, although not all of the comparisons were statistically significant. The lack of consistently significant findings could well be due to a combination of small sample size and relatively short observation periods.
See also this post.
* Those studies are:
- Sokol MC, McGuigan KA, Verbrugge RR, et al. Impact of medication adherence on hospitalization risk and healthcare cost. Med Care. 2005;43:521–530.
- Salas M, Hughes D, Zuluaga A, et al. Costs of medication nonadherence in patients with diabetes mellitus: a systematic review and critical analysis of the literature. Value Health. 2009;19:915–922.
- Lee WC, Balu S, Cobden D, et al. Prevalence and economic consequences of medication adherence in diabetes: a systematic literature review. Manag Care Interface. 2006;19:31–41.
- Encinosa WE, Bernard D, Dor AQ. Does prescription drug adherence reduce hospitalization and costs? The case of diabetes. Adv Health Econ Health Serv Res. 2010;22:151–173.
- Pelletier EM, Pawaskar M, Smith PJ, et al. Economic outcomes of exenatide vs. liraglutide in type 2 diabetes patients in the United States: results from a retrospective claims database analysis. J Med Econ. 2012;15:1039–1050.
- Gibson TB, Song X, Alemayehu B, et al. Cost sharing, adherence, and health outcomes in patients with diabetes. Am J Manag Care. 2010;16:589–600.
- Pawaskar MD, Camacho FT, Anderson RT, et al. Health care costs and medication adherence associated with initiation of insulin pen therapy in Medicaid-enrolled patients with type 2 diabetes: a retrospective database analysis. Clin Ther. 2007;29(pt 1):1294–1305.
- Stuart B, Loh FL, Roberto P, et al. Increasing Medicare Part D enrollment in medication therapy management could improve health and lower costs. Health Aff (Millwood). 2013;32:1212–1220
- Stuart B, Davidoff A, Lopert R, et al. Does medication adherence lower Medicare spending among beneficiaries with diabetes? Health Serv Res. 2011;46:1180–1199.
- Stuart B, Simoni-Wastila L, Zhao L, et al. Increased persistency in medication use by US Medicare beneficiaries with diabetes is associated with lower hospitalization rates and cost savings. Diabetes Care. 2009;32:647–649.
- Zhao Y, Zabriski S, Bertram C. Association between statin adherence level, health care costs, and utilization. J Man Care Pharm. 2014;20: 703–713.