This study used a clustering model, Hierarchical Classes Analysis (HICLAS), to examine patient groupings in a multiethnic sample of 1456 patients using primary care services at a university-affiliated community clinic in southern California. Somatic symptoms, psychiatric diagnoses and disability were studied using a survey instrument that included portions of the Composite International Diagnostic Interview (CIDI), the Diagnostic Interview Schedule (DIS) and the RAND-MOS Short Form Health Survey's (SF-36) 'physical functioning' dimension. HICLAS identified 11 clusters of patients with distinct patterns of medically unexplained somatic symptoms. These patient clusters varied with respect to psychiatric diagnoses and symptoms, gender, immigration status and disability. Results of this study suggest that the type of presenting symptom(s) and their various combinations may have diagnostic and prognostic value in primary care settings. These new findings may lead to further refinement of current diagnostic constructs for somatizing syndromes.

Background

Somatisation is a common and frustrating clinical problem in primary care.

Method

Using structural diagnoses and functional measures, we examined the prevalence and associated features of somatisation disorder defined by three current nosologies and an abridged construct in subjects using primary care services.

Results

Somatisation disorder, diagnosed according to the standard criteria, was found to have a very low prevalence (range 0.06-0.5%), while more than one-fifth of the sample (22%) met the criteria for the abridged diagnosis. There was poor agreement between succeeding versions of the DSM system for identifying cases of somatisation disorder, each system ending up with rather disparate sets of individuals as well as variable levels of psychopathology and disability.

Conclusions

According to these data, standard somatisation disorder diagnoses add little to the prediction of disability/psychopathology beyond the contributions of an abridged construct of somatisation.