Patients at-risk for cost-related medication nonadherence: a review of the literature.
OBJECTIVE
Up to 32% of older patients take less medication than prescribed to avoid costs, yet a comprehensive assessment of risk factors for cost-related nonadherence (CRN) is not available. This review examined the empirical literature to identify patient-, medication-, and provider-level factors that influence the relationship between medication adherence and medication costs.


METHODS
We conducted searches of four databases (MEDLINE, CINAHL, Sciences Citations Index Expanded, and EconLit) from 2001 to 2006 for English-language original studies. Articles were selected if the study included an explicit measure of CRN and reported results on covarying characteristics.


RESULTS
We found 19 studies with empirical support for concluding that certain patients may be susceptible to CRN: research has established consistent links between medication nonadherence due to costs and financial burden, but also to symptoms of depression and heavy disease burden. Only a handful of studies with limited statistical methods provided evidence on whether patients understand the health risks of CRN or to what extent clinicians influence patients to keep taking medications when faced with cost pressures. No relationship emerged between CRN and polypharmacy.


CONCLUSIONS
Efforts to reduce cost-related medication nonadherence would benefit from greater study of factors besides the presence of prescription drug coverage. Older patients with chronic diseases and mood disorders are at-risk for CRN even if enrolled in Medicare's new drug benefit.
Briesacher
Becky A
BA
Division of Geriatric Medicine and Meyers Primary Care Institute, University of Massachusetts Medical School, Biotech Four, Suite 315, 377 Plantation Street, Worcester, MA 01605, USA. Becky.Briesacher@umassmed.edu
Gurwitz
Jerry H
JH
Soumerai
Stephen B
SB
D002908:Chronic Disease / Q000188:drug therapy / Q000191:economics*; D017047:Cost Sharing / Q000191:economics; D017281:Cost of Illness; D003863:Depression; D006801:Humans; D004364:Pharmaceutical Preparations / Q000191:economics*; D019338:Polypharmacy; D011306:Prescription Fees; D012306:Risk; D018570:Risk Assessment / Q000191:economics; D012959:Socioeconomic Factors; D016312:Treatment Refusal
D004364:Pharmaceutical Preparations