Spiegel BMR et al. (2004) Clinical determinants of health-related quality of life in patients with irritable bowel syndrome. Arch Intern Med 164: 1773–1780

Despite guidelines recommending its routine evaluation, health-related quality of life (HRQOL) tends to be measured inaccurately in patients with irritable bowel syndrome (IBS). To help clinicians to provide better assessments, Spiegel et al. have identified a set of clinical determinants of HRQOL in patients with this condition.

The team selected 30 hypothesis-driven predictors of HRQOL, covering demographics, bowel symptoms, psychological symptoms and use of health care resources. Each of these was expressed as a dichotomous variable to simplify interpretation. A total of 770 patients with IBS were then examined using a symptom questionnaire. All patients also completed the 36-Item Short-Form Health Survey (SF-36), which is a validated, generic HRQOL instrument. Global HRQOL, as indicated by the SF-36, was the main outcome of the study.

Multivariate regression analysis showed that seven of the hypothesis-driven variables independently predicted physical HRQOL, whereas eight factors were similarly associated with mental HRQOL. Two variables ('tiring easily' and 'low in energy') were common to both the physical and mental HRQOL domains. Physical HRQOL was largely associated with the severity, periodicity and pain of symptoms. Mental HRQOL, however, was predicted by problems with sexual function/interest, mood and anxiety.

Concluding that overall HRQOL was mainly associated with extraintestinal symptoms, the authors recommend that factors such as stress and anxiety should be addressed. They note that the clinical determinants identified in this study might prove useful in assessing HRQOL in IBS.