Methods for Measuring Multiple Medication Adherence: A Systematic Review

Priti P. Pednekar, Tamás Ágh, Maria Malmenäs, Amit D. Raval, Bryan M. Bennett, Bijan J Borah, David S. Hutchins, Elizabeth Manias, Allison F. Williams, Mickaël Hiligsmann, Adina Turcu-Stiolica, John E. Zeber, Lusine Abrahamyan, Thomas J. Bunz, Andrew M. Peterson

Research output: Contribution to journalArticle

7 Scopus citations


Background: A broad literature base exists for measuring medication adherence to monotherapeutic regimens, but publications are less extensive for measuring adherence to multiple medications. Objectives: To identify and characterize the multiple medication adherence (MMA) methods used in the literature. Methods: A literature search was conducted using PubMed, PsycINFO, the International Pharmaceutical Abstracts, the Cumulative Index to Nursing and Allied Health Literature and the Cochrane Library databases on methods used to measure MMA published between January 1973 and May 2015. A two-step screening process was used; all abstracts were screened by pairs of researchers independently, followed by a full-text review identifying the method for calculating MMA. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to conduct this systematic review. For studies that met the eligibility criteria, general study and adherence-specific characteristics and the number and type of MMA measurement methods were summarized. Results: The 147 studies that were included originated from 32 countries, in 13 disease states. Of these studies, 26 used proportion of days covered, 23 used medication possession ratio, and 72 used self-reported questionnaires (e.g., the Morisky Scale) to assess MMA. About 50% of the studies included more than one method for measuring MMA, and different variations of medication possession ratio and proportion of days covered were used for measuring MMA. Conclusions: There appears to be no standardized method to measure MMA. With an increasing prevalence of polypharmacy, more efforts should be directed toward constructing robust measures suitable to evaluate adherence to complex regimens. Future research to understand the validity and reliability of MMA measures and their effects on objective clinical outcomes is also needed.

Original languageEnglish (US)
JournalValue in Health
StateAccepted/In press - Jan 1 2018
Externally publishedYes



  • measurement method
  • medication adherence
  • medication possession ratio
  • persistence
  • polypharmacy
  • proportion of days covered
  • self-reported measures

ASJC Scopus subject areas

  • Health Policy
  • Public Health, Environmental and Occupational Health

Cite this

Pednekar, P. P., Ágh, T., Malmenäs, M., Raval, A. D., Bennett, B. M., Borah, B. J., Hutchins, D. S., Manias, E., Williams, A. F., Hiligsmann, M., Turcu-Stiolica, A., Zeber, J. E., Abrahamyan, L., Bunz, T. J., & Peterson, A. M. (Accepted/In press). Methods for Measuring Multiple Medication Adherence: A Systematic Review. Value in Health.