Somatisation disorder and its associated factors in multiethnic primary care clinic attenders

Somatisation disorder (SD) has been reported as common in all ethnic groups, but the estimates of its prevalence have varied and the evidence for its associated factors has been inconsistent.

This study seeks to determine the prevalence of SD and its associated factors in multiethnic primary care clinic attenders.

This cross-sectional study was on clinic attenders aged 18 years and above at three urban primary care clinics in Malaysia. The operational definition of SD was based on ICD-10 criteria for SD for research, frequent attendance, and excluded moderate to severe anxiety and depression. The instruments used were the ICD-10 symptom list, the Hospital Anxiety and Depression Scale, a semi-structured questionnaire, and SF-36.

We recruited 1,763 patients (response rate 63.8%). The mean age of respondents was 44.7 ± 15.8 years, 807 (45.8%) were male; there were 35.3% Malay, 30.1% Chinese and 34.6% Indian. SD prevalence was 3.7%; the prevalence in Malay was 5.8%, Indian 3.0% and Chinese 2.1%. Significant associations were found between SD prevalence and ethnicity, family history of alcoholism, blue-collar workers and the physical component summary (PCS) score of SF-36. Multivariate analysis showed that SD predictors were Malay ethnicity (OR 2.7, 95% CI 1.6, 4.6), blue-collar worker (OR 2.0, 95% CI 1.2, 3.5) and impaired PCS score of SF-36 (OR 0.92, 95% CI 0.90, 0.95).

The prevalence of SD was relatively uncommon with the stringent operational criteria used. SD preponderance in blue-collar workers may be attributable to secondary gain from getting sickness certificates and being paid for time off work.