title: Development and validation of a new instrument to evaluate the ease of use of patient-controlled analgesic modalities for postoperative patients.
abstract: OBJECTIVE
  To describe the development and psychometric evaluation of a questionnaire assessing the ease of use that patients associate with patient-controlled analgesia (PCA) modalities.
  
  
  METHODS
  Qualitative interviews were conducted with patients who had experience with intravenous (IV) PCA for postoperative pain management to generate items relevant to the ease of using PCA modalities. The content validity of the resulting questionnaire was examined through follow-up patient interviews, and an expert panel reviewed the questionnaire. Cognitive debriefing interviews were conducted with patients to determine the clarity and content of the instructions, items, and response scales, and the ease of completing the instrument. Psychometric evaluation was performed with patients who had undergone surgery and received IV PCA for postoperative pain management. Item and scale quality and the internal consistency reliability of the questionnaire were assessed. Construct validity was evaluated by examining the relationship between subscales of the questionnaire with patient-reported outcome measures. Known-groups validity was determined by assessing the instrument's ability to differentiate between patients with versus without an IV PCA problem. A potential limitation of this study was the exclusive sampling of patients who had experience with IV PCA.
  
  
  RESULTS
  The Patient Ease-of-Care (EOC) Questionnaire included 23 items in the following subscales: Confidence with Device, Comfort with Device, Movement, Dosing Confidence, Pain Control, Knowledge/Understanding, and Satisfaction. Coefficient alpha reliability estimates were ≥ 0.66 for Overall EOC (includes all subscales except Satisfaction) and all EOC subscales. Construct validity was supported by the moderate relationship between the Pain Control subscale and measures of pain severity and pain interference; additional evidence of construct validity was provided by correlations of the Confidence with Device subscale, the Satisfaction subscale, and Overall EOC with measures of pain severity, pain interference, and satisfaction. Significant mean score differences were reported between participants with and without IV PCA problems for Overall EOC and for the Comfort with Device, Confidence with Device, Movement, Pain Control, and Satisfaction subscales indicating known-groups validity.
  
  
  CONCLUSIONS
  Results provide evidence for the reliability and validity of the Patient EOC Questionnaire as a measure of the ease of use that patients associate with PCA systems and may be useful for evaluating emerging PCA modalities.
authors.affiliation: Center for Health Outcomes Research, United BioSource Corporation, 7101 Wisconsin Avenue, Bethesda, MD 20814, USA. Gale.Harding@unitedbiosource.com
authors.forename: Gale
authors.initials: G
authors.lastname: Harding
authors.forename: Jeff R
authors.initials: JR
authors.lastname: Schein
authors.forename: Winnie W
authors.initials: WW
authors.lastname: Nelson
authors.forename: Sue
authors.initials: S
authors.lastname: Vallow
authors.forename: William H
authors.initials: WH
authors.lastname: Olson
authors.forename: David J
authors.initials: DJ
authors.lastname: Hewitt
authors.forename: Rosemary C
authors.initials: RC
authors.lastname: Polomano
mesh_terms: D016058:Analgesia, Patient-Controlled / Q000379:methods / Q000523:psychology / Q000706:statistics & numerical data*; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D011594:Psychometrics; D036301:Qualitative Research; D015203:Reproducibility of Results; D013223:Statistics as Topic; D011795:Surveys and Questionnaires