title: An electronic version of the PDQ-39: acceptability to respondents and assessment of alternative response formats.
abstract: BACKGROUND
  The PDQ-39 is the most thoroughly validated and widely used self-report instrument for the assessment of health-related quality of life in people with Parkinson's (PwP). Given the breadth of its use and increasing emphasis on electronic data capture, there may be significant benefit in validating an electronic version of the PDQ-39.
  
  
  OBJECTIVE
  Firstly, to migrate the paper-based version of the PDQ-39 to a computer based platform and assess its usability and acceptability to respondents. Secondly, to investigate the impact of implementing non-response options on response rates and data completeness.
  
  
  METHODS
  Six PwP participated in cognitive interviews in order to assess the usability and acceptability of the electronic version of the PDQ-39, the ePDQ. This was followed by an online survey of 129 PwP, randomly assigned to one of two groups; one required to provide a response to every item and one with the option to skip any item they did not wish to answer.
  
  
  RESULTS
  Cognitive interviews indicated that the ePDQ is acceptable to PwP, with positive feedback regarding layout, features and functionality. 125 PwP fully completed the ePDQ. Following randomization 60 participants completed the forced response ePDQ and 65 completed the non-forced version. Response rates of 98.4% were achieved for the forced response ePDQ and 95.6% for the non-forced. Missing value analyses calculated levels of missing data at below 5% in the non-forced sample.
  
  
  CONCLUSIONS
  The ePDQ is user-friendly and acceptable to respondents. Additionally, there appears little difference when implementing non-response options on response rates and data completeness.
authors.affiliation: Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: David
authors.initials: D
authors.lastname: Morley
authors.affiliation: Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Dummett
authors.affiliation: Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Kelly
authors.affiliation: Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: Jill
authors.initials: J
authors.lastname: Dawson
authors.affiliation: Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: Crispin
authors.initials: C
authors.lastname: Jenkinson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000523:psychology*; D011788:Quality of Life; D057566:Self Report
keywords: PDQ-39; Parkinson's disease questionnaire; ePDQ; ePRO; electronic patient reported outcome