A systematic review finds inconsistency in the measures used to estimate adherence and persistence to multiple cardiometabolic medications

Abstract

Objectives: We reviewed measures used to estimate adherence and persistence to multiple cardiometabolic medications from prescription data, particularly for blood pressure-lowering, lipid-lowering, and/or glucose-lowering medication, and give guidance on which measures to choose. Study Design and Setting: A literature search of Medline, Embase, and PsycINFO databases was conducted to identify studies assessing medication adherence and/or persistence for patients using multiple cardiometabolic medications. Two reviewers performed the study selection process independently. Results: From the 54 studies assessing adherence, only 36 (67%) clearly described the measures used. Five measures for adherence were identified, including adherence to ''all,'' to ''any,'' to ''both'' medication, ''average adherence,'' and ''highest/lowest adherence". From the 22 studies assessing persistence, only six (27%) clearly described the measures used. Three measures for persistence were identified, including persistence with ''all,'' with ''both,'' and with ''any'' medication. Less than half of the studies explicitly considered medication switches when relevant. Conclusion: From the identified measures, the ''any medication'' measure is most suitable for identifying patients in need of an intervention, whereas the ''all medication'' measure is useful for assessing the effect of interventions. More attention is needed for adequate measurement definitions when reporting on and interpreting adherence or persistence estimates to multiple medications.

Effect on Treatment Adherence of Distributing Essential Medicines at No Charge

“…19 The primary outcome was determined at 12 months by assessing whether each prescription was both appropriate (based on explicit criteria) and taken as prescribed for at least 80% of expected doses. 19 A participant was either classified as receiving only appropriate prescriptions and being adherent to all of them (evidence of taking at least 80% of expected doses), or as having either received at least 1 potentially inappropriate prescription or being nonadherent to at least 1 medicine. We reviewed primary care prescribing records to determine whether each prescription was potentially inappropriate using established criteria based only on the prescribed medicines (eAppendix 2 in Supplement 2).…”

Pharmacy-based predictors of non-adherence, non-persistence and reinitiation of antihypertensive drugs among patients on oral diabetes drugs in the Netherlands

“…Patients were considered non-adherent if at least one antihypertensive drug had an MPR < 80%, that is, not adherent to any of their antihypertensives. [15] Patients were excluded from the MPR calculation in the years after they had become non-persistent (Fig 1). Drug switches were defined as the start of a new antihypertensive drug within < 180 days of the discontinuation (gap > 180 days) of another antihypertensive drug.…”

“…Persistence was defined as continuously refilling a prescription for any antihypertensive drug without a gap > 180 days since the end of the last prescription[15], regardless of drug switches within or between drug classes or add-on drugs during follow-up. In the Netherlands, the average repeat prescription length for drugs used for chronic diseases is 90 days.…”

<p>Validity Of The Self-Reported Domains Of Subjective Extent Of Nonadherence (DOSE-Nonadherence) Scale In Comparison With Electronically Monitored Adherence To Cardiovascular Medications</p>

“…Results may not generalize to patients prescribed other types of medications, to regimens that comprise multiple cardiovascular medications, or to patients recruited outside of urban ED settings. Future studies should explore whether self-report scales are best used to measure adherence to a single medication or to regimen adherence more broadly 28. The DOSE-Nonadherence scale focuses on missed doses; extra doses or wrong timing of doses may be important as part of adherence measurement for other self-report adherence questionnaires.…”