title: Validation of a short version of the glaucoma medication self-efficacy questionnaire.
abstract: OBJECTIVE
  The aims of this study were: (1) to examine whether the original glaucoma medication adherence and eye drop technique self-efficacy scales could be shortened for easier use in practice settings; and (2) to validate these scales against objective medication adherence measures.
  
  
  METHODS
  Prospective study conducted at a single private practice site. We measured subjects' adherence to glaucoma medications through Medication Event Monitoring System (MEMS) devices and assessed eye drop instillation technique by video-recording. Principal components factor analysis and logistic and linear regression were used to analyse the data.
  
  
  RESULTS
  Our results yielded a 10-item Glaucoma Medication Adherence Self-Efficacy Scale that was strongly associated with subject adherence measured using MEMS (β coefficient 8.52, 95% CI 1.94 to 15.1). In addition, the six-item Eye Drop Technique Self-Efficacy Scale was strongly associated with video-recorded subject eye drop installation technique (OR 10.47, 95% CI 1.78 to 61.63).
  
  
  CONCLUSIONS
  Eye care providers and researchers could use these shorter scales to identify subjects with either poor glaucoma medication adherence and/or eye drop instillation technique. This could help to identify those who may benefit most from education and training on both adherence and eye drop instillation.
authors: Cecil G. Sheps Center for Health Services Research, Division of Pharmaceutical Outcomes and Policy, Eshelman School of Pharmacy, University of North Carolina, CB # 7590, Chapel Hill, NC 27599-7590, USA. betsy_sleath@unc.edu
authors: Betsy
authors: B
authors: Sleath
authors: Susan J
authors: SJ
authors: Blalock
authors: Jennifer L
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authors: Asheley Cockrell
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