Abstract
PURPOSE: Few existing measures assess constipationspecific quality of life. This study sought to develop a valid and reliable quality-of-life measure for constipation. METHODS: First, we created a preliminary instrument that assessed quality-of-life domains affected by constipation: body image, eating, mood, and relationships with others. We conducted focus groups both with patients with constipation seeking treatment and the health care providers who treat them. Next, a 59-item questionnaire was given to 240 subjects with constipation (83% female) and 103 healthy volunteers (63% female). Test-retest reliability and discriminant, convergent, and divergent validity were assessed. RESULTS: Exploratory factor analysis revealed four domains: Social Impairment (five items), Distress (six items), Eating Habits (three items), and Bathroom Attitudes (four items). Internal consistency and testretest reliability for all subscales was high (Cronbach's alpha = 0.89; intraclass correlation coefficient = 0.87). All domains discriminated well between subjects with constipation and healthy volunteers (P < 0.001). Convergent validity was excellent: all subscales correlated highly with the Irritable Bowel Syndrome Quality of Life Scale total score (P < 0.001) and the Medical Outcomes Study Short Form-36 physical component and mental component summary scores (P < 0.001). Scores from our Constipation-Related Quality of Life measure were not significantly correlated with the Social Desirability Scale, demonstrating divergent validity. CONCLUSIONS: Our findings support the reliability and validity of the Constipation-Related Quality of Life measure. Future validation of the Constipation-Related Quality of Life measure for assessing changes in quality of life in response to treatments for constipation is needed.
Original language | English (US) |
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Pages (from-to) | 1434-1442 |
Number of pages | 9 |
Journal | Diseases of the colon and rectum |
Volume | 52 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2009 |
Externally published | Yes |
Keywords
- Bowel questionnaire
- Constipation
- Quality-of-life measure
- Validation study