Psychometric performance and clinical meaningfulness of the Patient Assessment of Constipation-Quality of Life questionnaire in prucalopride (RESOLOR) trials for chronic constipation

Neurogastroenterol Motil. 2010 Feb;22(2):e54-63. doi: 10.1111/j.1365-2982.2009.01408.x. Epub 2009 Sep 17.


Background: The Patient Assessment of Constipation-Quality of Life (PAC-QOL) is a self-reported questionnaire measuring health-related quality of life (HRQL) of constipated patients and was used as secondary endpoint in three identical double-blind, randomized, placebo-controlled Phase III clinical trials. These 12-week trials in subjects with severe chronic constipation evaluated the effects of prucalopride, a selective 5-HT(4) agonist given orally once daily.

Methods: To consolidate the main treatment effect results observed in the prucalopride trial populations, analyses were undertaken on the pooled data of the three trials to confirm the psychometric properties of the PAC-QOL and to provide guidance for the interpretation of the clinical significance of its scores.

Key results: The evaluation of the psychometric properties confirmed the PAC-QOL reliability, validity and responsiveness to measure the impact of chronic constipation symptoms on HRQL in the prucalopride trials. The 1-point improvement in PAC-QOL scores used as target response level for the main treatment effect analyses was validated as a relevant definition of response for treatment group comparisons. Cumulative distribution curves, drawn for each treatment group to provide more complete information on treatment effects than single minimal important difference point estimates, demonstrated consistent superior effects of prucalopride over placebo on all PAC-QOL scores.

Conclusions & inferences: The PAC-QOL questionnaire is a useful measurement tool to assess, from a patient perspective, the potential therapeutic value of chronic constipation treatments in clinical trials and, by directly reflecting the patient's own perspective on constipation and its treatment, eventually also for informing daily medical practice.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Benzofurans / therapeutic use*
  • Chronic Disease
  • Constipation / drug therapy*
  • Double-Blind Method
  • Female
  • Health Status
  • Humans
  • Male
  • Middle Aged
  • Patient Satisfaction
  • Psychometrics
  • Quality of Life*
  • Reproducibility of Results
  • Severity of Illness Index
  • Surveys and Questionnaires*
  • Treatment Outcome


  • Benzofurans
  • prucalopride