Objective: Several recent studies have documented that substantial functional impairment is associated with many of the mental disorders seen in primary care. However, brief measures of mental health-related functional impairment are not commonly applied in primary care settings. The Sheehan Disability Scale (SDS), a three-item instrument for assessing such impairment, is evaluated in this study.
Method: A psychometric analysis of the SDS was conducted with a sample of 1001 primary care patients at Kaiser Permanente In Oakland, California. The SDS and the Symptom Driven Diagnostic System for Primary Care assessments were completed.
Results: The internal consistency reliability of the SDS is high, with coefficient alpha of 0.89. The construct validity was substantiated in two ways. A one-factor model fit the data quite well. Furthermore, patients with each of six psychiatric disorders had significantly higher impairment scores than those who did not. Finally, over 80 percent of the patients with mental disorder diagnoses had an elevated SDS score and nearly 50 percent of those with elevated SDS scores had at least one disorder.
Conclusions: The psychometric properties of the SDS were evaluated in primary care. The internal consistency reliability was high. The analyses also lend empirical support for the construct validity. The scale is a sensitive tool for identifying primary care patients with mental health-related functional impairment, who would warrant a diagnostically-oriented mental health assessment.