Is there an independent somatic symptom dimension in older people?

In explaining the dimensions underlying nonpsychotic symptom reporting, traditional psychiatric paradigm has advocated a hierarchical model in which somatic symptoms are subsumed within two correlated psychological dimensions. A more recent alternate view is that somatic symptoms may be clearly separated from typical anxiety and depression symptoms if somatic symptoms are adequately recorded. The main aim of this study is to determine whether discrete somatic dimension(s) could be derived in older people.

Exploratory factor analysis was used to determine the factor structure underlying the responses of 10662 ambulatory primary care patients, aged 60 years and over, who completed the 34-item SPHERE (Somatic and Psychological HEalth REport) questionnaire of somatic and psychological symptoms. In addition, weighted factor scores were compared according to whether there was a physical or psychological reason for presentation to a doctor.

A clinically interpretable four-factor solution, consisting of mood, cognitive, musculoskeletal, and fatigue symptoms, was derived. When factor analysis was repeated by gender, the only difference was that mood, cognitive, and pain-fatigue factors were derived in males. In the overall sample, all factor scores were higher in patients with a purely psychological reason for presentation.

Somatic symptoms could be measured independently of psychological symptoms in the current sample of older primary care patients.