Psychosocial risk factors for the onset of abdominal pain. Results from a large prospective population-based study.

Objective: To determine the psychosocial risk factors for the development of abdominal pain and to determine whether, in those people who consulted, symptoms had been attributed to an organic cause.

Design: Prospective population-based postal survey with follow-up survey at 12 months.

Setting: A mixed sociodemographic suburban area of Manchester, UK.

Participants: Subjects aged 18-65 years were randomly selected from a population-based primary care register who had responded to a detailed pain questionnaire, which included a pain manikin drawing. They also completed the following psychosocial instruments: General Health Questionnaire, Somatic Symptom Checklist, Fatigue Questionnaire and the Illness Attitude Scales (including the 'health anxiety' and 'illness behaviour' sub-scales).

Main Outcome Measures: The onset of new abdominal pain.

Results: Of the 1953 participants at baseline, 1763 were free of abdominal pain: 1551 were followed up at 12 months (adjusted follow-up rate of 92%) of which 69 subjects reported new abdominal pain (new onset rate 4.6%). New abdominal pain was similar in females (4.9%) and males (4.2%), and did not vary by age group. Baseline factors which predicted onset were high levels of fatigue (odds ratio [OR] = 3.3, 95% CI: 1.9-5.8), psychological distress (OR = 3.4, 95% CI: 1.9-6.0), high scores on the illness behaviour scale (OR = 3.3, 95% CI: 1.7-6.7) and high levels of health anxiety (OR = 2.1, 95% CI: 1.1-3.9). Reporting low back pain at baseline was also associated with an increased risk of reporting abdominal pain (OR = 2.0, 95% CI: 1.2-3.3). On multivariate analysis, high levels of psychological distress and aspects of prior illness behaviour were the major independent predictors of outcome. Of those who sought health care, only one consultation led to a definite diagnosis.

Conclusion: In subjects free of abdominal pain, psychological distress, fatigue, health anxiety and illness behaviour are predictors of future onset rather than merely a consequence of symptoms. These results suggest that abdominal pain shares some common features of onset with pain at other sites thought not to be primarily organic in origin.