Poor self-rated health and its associations with somatisation in two Australian national surveys

OBJECTIVES It is hypothesised that across two national surveys poor self-rated health will be independently associated with somatisation and will result in high rates of service use after adjusting for established diagnoses. DESIGN Two cross-sectional population-based surveys were conducted in 1997 and 2007. The use of both surveys allowed replication of results. SETTING Australia. PARTICIPANTS The 1997 and 2007 National Surveys of Mental Health and Well-Being were based on stratified, multistage area probability samples of persons living in private dwellings in Australia. The 1997 survey included 10 641 respondents aged 18-75 years, a response rate of 78%. The 2007 survey included 8841 respondents aged 16-85 years, a response rate of 60%. MAIN OUTCOME MEASURES Self-rated health. RESULTS Approximately 15% of the Australian population rated their health as fair or poor in both surveys. The independent relationship between self-rated health and somatisation was replicated across both surveys in multivariate analyses. Individuals with negative self-rated health were 4.1 times as likely to screen positive for health anxiety (OR 4.1, 95% CI 2.8 to 5.9) and 3.4 times as likely to be diagnosed with neurasthenia (OR 3.4, 95% CI 2.2 to 5.2), when compared with individuals who rated their health positively. Individuals with negative self-rated health were also more likely to use health services after controlling for demographics and mental and physical illness. CONCLUSIONS These results confirm both of the study hypotheses: (1) that negative self-rated health was powerfully and independently associated with somatisation and (2) that this relationship manifested itself in high rates of service use, even after adjusting for an extensive range of demographics and psychiatric and physical conditions.