Abstract
Objectives: A systematic literature review was conducted comparing different approaches estimating persistence and adherence in chronic diseases with polypharmacy of oral and subcutaneous treatments.
Methods: This work followed published guidance on performing systematic reviews. Twelve electronic databases and grey literature sources were used to identify studies and guidelines for persistence and adherence of oral and subcutaneous therapies in hypercholesterolemia, type 2 diabetes, hypertension, osteoporosis and rheumatoid arthritis. Outcomes of interest of each persistence and adherence data collection and calculation method included pros: accurate, easy to use, inexpensive; and cons: inaccurate, difficult to use, expensive.
Results: A total of 4158 records were retrieved up to March 2017. We included 16 observational studies, 5 systematic reviews and 7 guidelines, in patients with hypercholesterolemia (n = 8), type 2 diabetes (n = 4), hypertension (n = 2), rheumatoid arthritis (n = 1) and mixed patient populations (n = 13). Pharmacy and medical records offer an accurate, easy and inexpensive data collection method. Pill count, medication event monitoring systems (MEMs), self-report questionnaires and observer report are easy to use. MEMS and biochemical monitoring tests can be expensive. Proportion of days covered (PDC) was recommended as a gold standard calculation method for long-term treatments. PDC avoids use of days’ supply in calculation, hence is more accurate compared to medication possession ratio (MPR) to assess adherence to treatments in chronic diseases.
Conclusions: Decisions on what method to use should be based on considerations of the route of medication administration, the resources available, setting and aim of the assessment. Combining different methods may provide wider insights into adherence and persistence, including patient behavior.
Transparency
Declaration of funding
This study was funded by Amgen Europe GmbH.
Author contributions: C.A.F.: concept and design; data inclusion assessment; data extraction and quality assessment; data analysis and interpretation; drafting and final approval of the manuscript. S.De.: concept and design; data inclusion assessment; data extraction and quality assessment; data analysis and interpretation; manuscript draft and final approval. S.Du.: concept and design; literature searching; drafting and final approval of the manuscript. F.S.-V. and L.K.: concept and design; data review; interpretation; drafting and final approval of the manuscript. I.G.-B. and E.H.: concept and design; data review; interpretation; drafting and final approval of the manuscript.
Declaration of financial/other relationships
C.A.F., S.De. and S.Du. have disclosed that they are employees of KSR Ltd, an independent research company paid by Amgen to conduct this research. I.G.-B. has disclosed that she is consultant to Amgen, Sanofi, Lilly and Regeneron and has participated in Speakers Bureaus for Amgen and Sanofi. E.H. has disclosed that he is consultant to Amgen, Sanofi, Ariad and MSD; and has received research grants from Amgen, GSK, AstraZeneca and Sanofi; in addition, he has participated in Speakers Bureaus for Amgen, Boehringer Ingelheim, AstraZeneca, Sanofi and NovoNordisk; finally, he is the National Coordinator/ARO-coordinator for the following trials: Sanofi ODYSSEY outcomes; DalCore DAL310; Regeneron R1500-CL-1643; and Aegis II/Perfuse. L.K. and F.S.-V. have disclosed that they are employees and stockholders of Amgen.
CMRO peer reviewers on this manuscript have received an honorarium from CMRO for their review work, but have no relevant financial or other relationships to disclose.
Acknowledgements
The authors acknowledge the help of Kim Reid and Vanesa Huertas Carrera who assisted with data extraction and quality assessment.