• Open Access

Frequency of and reasons for medication non-fulfillment and non-persistence among American adults with chronic disease in 2008


Colleen A. McHorney, PhD
Senior Director, US Outcomes Research
Merck & Co., Inc.
351 North Sumneytown Pike
North Wales, PA 19454
E-mail: colleen_mchorney@merck.com


Objective  To identify self-reported reasons why adults with chronic disease do not fill a new prescription (medication non-fulfillment) and/or stop taking a medication without their physician telling them to do so (lack of medication persistence).

Methods  Participants were sampled in 2008 from a national, internet-based panel of American adults with chronic disease. A total of 19 830 respondents answered questions about medication non-fulfillment and medication non-persistence and reasons for non-fulfillment and non-persistence. Among persons self-identified as non-fulfillers and non-persisters, statistical analyses assessed the association between reported reasons for non-fulfillment and non-persistence and chronic disease. A subsample of respondents completed an additional survey which included multi-item scales assessing matched constructs of most of the reasons for non-fulfillment and non-persistence. The convergent validity of the self-reported reasons was assessed against the multi-item scales.

Results  The same four reasons were most commonly reported for both medication non-fulfillment and medication non-persistence: paying for the medication a financial hardship (56 and 43%, respectively); fear or experience of side effects (46 and 35%, respectively); generic concerns about medications (32 and 23%, respectively); and lack of perceived need for the medication (25 and 23%, respectively). The frequency with which the reasons were reported varied somewhat by chronic disease. The convergent validity of most of the self-reported reasons was confirmed against multi-item scales measuring matched constructs.

Conclusions  The same top reasons for medication non-fulfillment and non-adherence were observed in a large internet-based sample of American adults with chronic disease. Future efforts to improve medication adherence should address patients’ medication concerns, perceived need for medications, and perceived medication affordability.