Predictors of health-related quality of life in patients with irritable bowel syndrome. A cross-sectional study in Norway

BACKGROUND Reduced quality of life (QoL) is often the main problem for patients with irritable bowel syndrome (IBS). This study aimed at finding predictors of reduced physical and mental quality of life (QoL) accessible for intervention. METHODS Consecutive patients with IBS (according to the Rome II criteria) visiting a general practitioner were included in a prospective cohort study and followed up for 6-9 months. At the last visit, information about sociodemographic characteristics, abdominal complaints, QoL and a range of physical and mental comorbidities were collected. Physical and mental QoL were measured with the generic QoL instrument Short Form-12 Physical Component Score (SF-12 PCS) and Short Form-12 Mental Component Score (SF-12 MCS) respectively. The normal scores are 50. This cross-sectional study used data from the last visit. RESULTS Out of 208 patients included in the cohort study, 149 (female/male: 105/44) with a mean age of 52 years (SD 15.3) were available for the analyses. Physical and mental QoL were reduced, the mean SF-12 PCS and SF-12 MCS scores were 38.4 (SD 11.9) and 45.0 (SD 11.3) respectively. The main independent predictors of low SF-12 PCS and SF-12 MCS were subjective health complaints and organic diseases, and affective disorders respectively. The severity of IBS symptoms was of minor clinical importance. CONCLUSIONS To help patients with IBS and reduced QoL, treatment should focus on QoL and not on relief of IBS symptoms. The different causes of reduced physical and mental QoL make an individually directed treatment necessary.