A hierarchical classes analysis (HICLAS) of primary care patients with medically unexplained somatic symptoms

Michael A Gara,Roxanne Cohen Silver,Javier I Escobar,Alison Holman,Howard Waitzkin

doi:10.1016/s0165-1781(98)00088-2

Abstract

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.

Highlights

Somatizing syndromes have been described throughout the years under protean labels Že.g. ‘ennui’, ‘hysteria’, ‘hypochondriasis’, ‘neurasthenia’. shaped by the medical model dominant at the time ŽShorter, 1993
This study represents the first application of HICLAS for examining how primary care patients cluster with respect to medically unexplained somatic complaints
Eleven patient clusters were identified with distinct patterns of somatic symptoms

Summary

Introduction

Somatizing syndromes have been described throughout the years under protean labels Že.g. ‘ennui’, ‘hysteria’, ‘hypochondriasis’, ‘neurasthenia’. shaped by the medical model dominant at the time ŽShorter, 1993. Regardless of fashion or prevailing paradigms, somatic presentations have had a place of their own in descriptive psychopathology. ‘hysteria’., the word ‘somatization’, denoting psychological causality, was incorporated into clinical discourse. In current diagnostic systems, ‘somatoform’ became the term used to signify an overarching category that subsumed somatization disorder as well as other disorders, such as hypochondriasis, that involved medically unexplained physical symptoms. The acceptance of the two terms remains confined to the area of psychiatry and clinical psychology. Because hypochondriasis and somatization disorder Žthe two most distinctive and valid somatoform diagnoses. Have low prevalence rates and fail to capture the large majority of patients presenting with unexplained medical symptoms, there is a need to develop systems of classification that are more ‘user-friendly’ and that can be shared with and accepted by primary care physicians Because hypochondriasis and somatization disorder Žthe two most distinctive and valid somatoform diagnoses. have low prevalence rates and fail to capture the large majority of patients presenting with unexplained medical symptoms, there is a need to develop systems of classification that are more ‘user-friendly’ and that can be shared with and accepted by primary care physicians

Methods

Results

Conclusion