Abstract
BACKGROUND: The prevalence of major depressive disorder (MDD) is highest in working age people and depression causes significant impairment in occupational functioning. Work productivity and work absence should be incorporated into clinical assessments but currently available scales may not be optimized for clinical use. This study seeks to validate the Lam Employment Absence and Productivity Scale (LEAPS), a 10-item self-report questionnaire that takes 3-5 minutes to complete. METHODS: The study sample consisted of consecutive patients attending a Mood Disorders outpatient clinic who were in full- or part-time paid work. All patients met DSM-IV criteria for MDD and completed during their intake assessment the LEAPS, the self-rated version of the Quick Inventory for Depressive Symptomatology (QIDS-SR), the Sheehan Disability Scale (SDS) and the Health and Work Performance Questionnaire (HPQ). Standard psychometric analyses for validation were conducted. RESULTS: A total of 234 patients with MDD completed the assessments. The LEAPS displayed excellent internal consistency as assessed by Cronbach's alpha of 0.89. External validity was assessed by comparing the LEAPS to the other clinical and work functioning scales. The LEAPS total score was significantly correlated with the SDS work disability score (r = 0.63, p < 0.01) and the Global Work Performance rating from the HPQ (r = -0.79, p < 0.01). The LEAPS total score also increased with greater depression severity. CONCLUSION: The LEAPS displays good internal and external validity in a population of patients with MDD attending an outpatient clinic, which suggests that it may be a clinically useful tool to assess and monitor work functioning and productivity in depressed patients.