title: Adherence measurement and patient recruitment methods are poor in intervention trials to improve patient adherence.
abstract: OBJECTIVE
  To develop a scale and survey the measurement of patient adherence and patient recruitment, and to explore how these methods impact the results in randomized controlled trials of interventions to improve patient adherence to medications.
  
  
  METHODS
  Analytic survey of a purposively selected sample of patient adherence intervention trials from a systematic review, assessing the quality of adherence measurement and patient recruitment methods.
  
  
  RESULTS
  We identified 44 different measures of adherence, with qualities ranging from valid and objective to unreliable and subjective. The median overall quality of measures of adherence was 5 (interquartile range [IQR], 3; range, 0-9, 9 is high quality). The quality of the measures was associated with variation in the estimate of adherence (Spearman r = 0.66; 95% confidence interval: 0.39, 0.83). The median overall quality of patient recruitment methods was 2 (IQR, 1; maximum score 6, higher is better). There was no significant correlation between the power of the trial to detect an effect and the quality of the patient recruitment methods.
  
  
  CONCLUSIONS
  Measurement and recruitment methods in adherence trials varied considerably, and most methods were of low quality. Adherence research could be advanced by using higher quality measures of adherence and better selection and baseline assessment of study participants.
authors.affiliation: Health Information Research Unit, Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1; Faculty of Medicine, Dalhousie University, 1459 Oxford Street, Halifax, Nova Scotia, Canada, B3H 4R2.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Jeffery
authors.affiliation: Health Information Research Unit, Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1.
authors.forename: Tamara
authors.initials: T
authors.lastname: Navarro
authors.affiliation: Health Information Research Unit, Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Wilczynski
authors.affiliation: Health Information Research Unit, Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1.
authors.forename: Emma C
authors.initials: EC
authors.lastname: Iserman
authors.affiliation: Health Information Research Unit, Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1.
authors.forename: Arun
authors.initials: A
authors.lastname: Keepanasseril
authors.affiliation: Health Information Research Unit, Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1.
authors.forename: Bhairavi
authors.initials: B
authors.lastname: Sivaramalingam
authors.affiliation: Health Information Research Unit, Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1.
authors.forename: Thomas
authors.initials: T
authors.lastname: Agoritsas
authors.affiliation: Health Information Research Unit, Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1; Department of Medicine, McMaster University, Health Sciences Centre, 1200 Main Street West, Hamilton, Ontario, Canada, L8N 3Z5. Electronic address: bhaynes@mcmaster.ca.
authors.forename: R Brian
authors.initials: RB
authors.lastname: Haynes
mesh_terms: D006801:Humans; D010349:Patient Compliance / Q000706:statistics & numerical data*; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D015203:Reproducibility of Results; D012107:Research Design / Q000592:standards*
keywords: Adherence; Measurement; Methodology; Patient recruitment; Quality; Systematic review