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.

Key words::

• healthcare professionals
• instrument development
• pain management
• patient-controlled analgesia
• psychometric evaluation
• questionnaire

Acknowledgments

Declaration of Interest: This study was supported by Ortho-McNeil Janssen Scientific Affairs, LLC. G.H. has disclosed that she is an employee of United BioSource Corporation; J.R.S. has disclosed that he is an employee of Ortho-McNeil Janssen Scientific Affairs, LLC; W.W.N. has disclosed that she is an employee of Johnson & Johnson; S.V. has disclosed that she is an employee of Johnson & Johnson Pharmaceutical Services, LLC; W.H.O. has disclosed that he is an employee of Ortho-McNeil Janssen Scientific Affairs, LLC; D.J.H. has disclosed that he was an employee of Johnson & Johnson at the time this research was conducted; R.P. has disclosed that she is on the Speakers' Bureau for Ortho-McNeil Pharmaceuticals, Wyeth Pharmaceuticals, and King Pharmaceuticals.

A portion of the results included in this manuscript was presented at the 25th Annual Scientific Meeting of the American Pain Society, May 3–6, 2006.

The authors would like to thank Nancy K. Leidy, PhD, United BioSource Corporation; Eugene Viscusi, MD, Thomas Jefferson University, Philadelphia, PA; and Ming Zhang, PhD, Ortho-McNeil Janssen Scientific Affairs, LLC for their assistance in the design of the Patient EOC Questionnaire, and Carmela Benson, MS, Ortho-McNeil Janssen Scientific Affairs, LLC for reviewing this paper. Editorial assistance was provided by Ashley O'Dunne, PhD, of MedErgy and funded by Ortho-McNeil Janssen Scientific Affairs, LLC.