Comparison of methods to assess medication adherence and classify Nonadherence

Richard A. Hansen, Mimi M. Kim, Liping Song, Wanzhu Tu, Jingwei Wu, Michael Murray

Research output: Contribution to journalArticle

160 Citations (Scopus)

Abstract

background: Medication adherence is suboptimal, and clinicians and researchers struggle with identifying nonadherent patients. Various measures of medication adherence exist, but there is controversy regarding which measures provide acceptable data and how nonadherence should be defined. objective: To assess agreement among patient self-report, pharmacy refill, and electronic adherence measures and compare the sensitivity and specificity of different cut-points for defining nonadherence. methods: Data were analyzed from 2 similarly designed randomized controlled trials that assessed a pharmacist's intervention to improve medication adherence among patients with hypertension or heart failure. For each participant, adherence was measured by patient self-report, prescription refill records, and electronic lids on medication containers. Agreement among measures was assessed using Spearman's correlation coefficient rho. Correlation coefficients were compared by patient characteristics using Fisher's Z transformation. The sensitivity and specificity of different cut-points for defining nonadherence were calculated. results: Median adherence was 84% for self-report. 86% for electronic, and 91% for prescription refill adherence measurement. Refill and electronic adherence demonstrated the best agreement among measures (rho = 0.48). Age, depression, and other comorbid conditions influenced agreement among measures. Measures were generally in agreement, regardless of how nonadherence was defined. A cut-point of 80% illustrated a fair balance between sensitivity and specificity for all measures. conclusions: All measures provided similar estimates of overall adherence, although refill and electronic measures were in highest agreement. In selection of a measure, practitioners should consider population and disease characteristics, since measurement agreement could be influenced by these and other factors. The commonly used, clinically based cut-point of 80% had a reasonable balance between sensitivity and specificity in studies of adherence in patients with heart failure or hypertension.

Original languageEnglish
Pages (from-to)413-422
Number of pages10
JournalAnnals of Pharmacotherapy
Volume43
Issue number3
DOIs
StatePublished - Mar 2009

Fingerprint

Medication Adherence
Self Report
Sensitivity and Specificity
Heart Failure
Electronic Prescribing
Hypertension
Population Characteristics
Patient Compliance
Pharmacists
Prescriptions
Randomized Controlled Trials
Research Personnel
Depression

Keywords

  • Adherence
  • Electronic lids
  • Refill records
  • Self-report

ASJC Scopus subject areas

  • Pharmacology (medical)

Cite this

Comparison of methods to assess medication adherence and classify Nonadherence. / Hansen, Richard A.; Kim, Mimi M.; Song, Liping; Tu, Wanzhu; Wu, Jingwei; Murray, Michael.

In: Annals of Pharmacotherapy, Vol. 43, No. 3, 03.2009, p. 413-422.

Research output: Contribution to journalArticle

Hansen, Richard A. ; Kim, Mimi M. ; Song, Liping ; Tu, Wanzhu ; Wu, Jingwei ; Murray, Michael. / Comparison of methods to assess medication adherence and classify Nonadherence. In: Annals of Pharmacotherapy. 2009 ; Vol. 43, No. 3. pp. 413-422.
@article{a659a2b74ba24c84b6b177b8e0424f1f,
title = "Comparison of methods to assess medication adherence and classify Nonadherence",
abstract = "background: Medication adherence is suboptimal, and clinicians and researchers struggle with identifying nonadherent patients. Various measures of medication adherence exist, but there is controversy regarding which measures provide acceptable data and how nonadherence should be defined. objective: To assess agreement among patient self-report, pharmacy refill, and electronic adherence measures and compare the sensitivity and specificity of different cut-points for defining nonadherence. methods: Data were analyzed from 2 similarly designed randomized controlled trials that assessed a pharmacist's intervention to improve medication adherence among patients with hypertension or heart failure. For each participant, adherence was measured by patient self-report, prescription refill records, and electronic lids on medication containers. Agreement among measures was assessed using Spearman's correlation coefficient rho. Correlation coefficients were compared by patient characteristics using Fisher's Z transformation. The sensitivity and specificity of different cut-points for defining nonadherence were calculated. results: Median adherence was 84{\%} for self-report. 86{\%} for electronic, and 91{\%} for prescription refill adherence measurement. Refill and electronic adherence demonstrated the best agreement among measures (rho = 0.48). Age, depression, and other comorbid conditions influenced agreement among measures. Measures were generally in agreement, regardless of how nonadherence was defined. A cut-point of 80{\%} illustrated a fair balance between sensitivity and specificity for all measures. conclusions: All measures provided similar estimates of overall adherence, although refill and electronic measures were in highest agreement. In selection of a measure, practitioners should consider population and disease characteristics, since measurement agreement could be influenced by these and other factors. The commonly used, clinically based cut-point of 80{\%} had a reasonable balance between sensitivity and specificity in studies of adherence in patients with heart failure or hypertension.",
keywords = "Adherence, Electronic lids, Refill records, Self-report",
author = "Hansen, {Richard A.} and Kim, {Mimi M.} and Liping Song and Wanzhu Tu and Jingwei Wu and Michael Murray",
year = "2009",
month = "3",
doi = "10.1345/aph.1L496",
language = "English",
volume = "43",
pages = "413--422",
journal = "Annals of Pharmacotherapy",
issn = "1060-0280",
publisher = "Harvey Whitney Books Company",
number = "3",

}

TY - JOUR

T1 - Comparison of methods to assess medication adherence and classify Nonadherence

AU - Hansen, Richard A.

AU - Kim, Mimi M.

AU - Song, Liping

AU - Tu, Wanzhu

AU - Wu, Jingwei

AU - Murray, Michael

PY - 2009/3

Y1 - 2009/3

N2 - background: Medication adherence is suboptimal, and clinicians and researchers struggle with identifying nonadherent patients. Various measures of medication adherence exist, but there is controversy regarding which measures provide acceptable data and how nonadherence should be defined. objective: To assess agreement among patient self-report, pharmacy refill, and electronic adherence measures and compare the sensitivity and specificity of different cut-points for defining nonadherence. methods: Data were analyzed from 2 similarly designed randomized controlled trials that assessed a pharmacist's intervention to improve medication adherence among patients with hypertension or heart failure. For each participant, adherence was measured by patient self-report, prescription refill records, and electronic lids on medication containers. Agreement among measures was assessed using Spearman's correlation coefficient rho. Correlation coefficients were compared by patient characteristics using Fisher's Z transformation. The sensitivity and specificity of different cut-points for defining nonadherence were calculated. results: Median adherence was 84% for self-report. 86% for electronic, and 91% for prescription refill adherence measurement. Refill and electronic adherence demonstrated the best agreement among measures (rho = 0.48). Age, depression, and other comorbid conditions influenced agreement among measures. Measures were generally in agreement, regardless of how nonadherence was defined. A cut-point of 80% illustrated a fair balance between sensitivity and specificity for all measures. conclusions: All measures provided similar estimates of overall adherence, although refill and electronic measures were in highest agreement. In selection of a measure, practitioners should consider population and disease characteristics, since measurement agreement could be influenced by these and other factors. The commonly used, clinically based cut-point of 80% had a reasonable balance between sensitivity and specificity in studies of adherence in patients with heart failure or hypertension.

AB - background: Medication adherence is suboptimal, and clinicians and researchers struggle with identifying nonadherent patients. Various measures of medication adherence exist, but there is controversy regarding which measures provide acceptable data and how nonadherence should be defined. objective: To assess agreement among patient self-report, pharmacy refill, and electronic adherence measures and compare the sensitivity and specificity of different cut-points for defining nonadherence. methods: Data were analyzed from 2 similarly designed randomized controlled trials that assessed a pharmacist's intervention to improve medication adherence among patients with hypertension or heart failure. For each participant, adherence was measured by patient self-report, prescription refill records, and electronic lids on medication containers. Agreement among measures was assessed using Spearman's correlation coefficient rho. Correlation coefficients were compared by patient characteristics using Fisher's Z transformation. The sensitivity and specificity of different cut-points for defining nonadherence were calculated. results: Median adherence was 84% for self-report. 86% for electronic, and 91% for prescription refill adherence measurement. Refill and electronic adherence demonstrated the best agreement among measures (rho = 0.48). Age, depression, and other comorbid conditions influenced agreement among measures. Measures were generally in agreement, regardless of how nonadherence was defined. A cut-point of 80% illustrated a fair balance between sensitivity and specificity for all measures. conclusions: All measures provided similar estimates of overall adherence, although refill and electronic measures were in highest agreement. In selection of a measure, practitioners should consider population and disease characteristics, since measurement agreement could be influenced by these and other factors. The commonly used, clinically based cut-point of 80% had a reasonable balance between sensitivity and specificity in studies of adherence in patients with heart failure or hypertension.

KW - Adherence

KW - Electronic lids

KW - Refill records

KW - Self-report

UR - http://www.scopus.com/inward/record.url?scp=62949217788&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=62949217788&partnerID=8YFLogxK

U2 - 10.1345/aph.1L496

DO - 10.1345/aph.1L496

M3 - Article

VL - 43

SP - 413

EP - 422

JO - Annals of Pharmacotherapy

JF - Annals of Pharmacotherapy

SN - 1060-0280

IS - 3

ER -