Objective: To evaluate the diagnosis of patients with somatisation disorders in primary care, and the effectiveness of coordinated care and evidence-based care planning on psychiatric symptoms and quality of life for these patients.

Design, setting and participants: This was a project of the SA HealthPlus Coordinated Care Trial, comprising a randomised controlled trial of 124 subjects recruited by general practitioners in southern Adelaide. Eligible patients had a GP diagnosis of somatisation, including unexplained physical symptoms as part of anxiety, chronic pain or somatoform disorders. Diagnoses were checked using the Composite International Diagnostic Interview (CIDI). The study was conducted from December 1997 to December 1999.

Intervention: A care plan including treatment for depression and anxiety disorders, a containment strategy for somatisation, and service coordinator-assisted self-management. Control patients received standard treatment.

Main outcome measures: Psychiatric symptoms; quality of life; medication use; and depression, anxiety and hostility scores.

Results: Compared with CIDI diagnoses, mood disorders in patients were underdiagnosed by GPs (64 v 31), particularly major depression (46 v 1). At 12 months, the intervention group showed reductions in depression (P = 0.002), guilt (P = 0.006) and anxiety (state, P = 0.043; trait, P = 0.001). Compared with the control group, physical role functioning improved for the intervention group (P = 0.006), and their medication use decreased by 8.9%.

Conclusions: Conservative management, treatment of depression, and case management by service coordinators is effective in managing somatising patients in primary care. GPs require training in the diagnosis of depression and how to say "no" to patients with unexplained physical symptoms who request further unnecessary investigations or referrals.