Improving health and productivity of depressed workers: a pilot randomized controlled trial of telephone cognitive behavioral therapy delivery in workplace settings

Objective: To examine the feasibility of telephone-delivered cognitive behavioral therapy (T-CBT) in an occupational context, with reference to participant recruitment, treatment adherence, follow-up and effect.

Method: Eligible participants comprised all employees of a large communications company with authorized work absence due to mild/moderate mental health difficulties over a 10-month period. Fifty-three consenting participants were centrally randomized to 12 weeks T-CBT or usual care, with minimization on age, gender and illness severity. Primary (symptom severity) and secondary outcomes (self-rated work performance and productivity) were measured at baseline and 3-months via postal questionnaires. Intention-to-treat analysis comprised multiple regression modeling with adjustment for missing response predictors, minimization variables and baseline values.

Results: Twenty-three employees attended one or more T-CBT sessions. T-CBT was associated with medium-large effects sizes on clinical outcomes (0.63-0.77) and work productivity scores (0.75-0.88). Twenty-one patients failed to return 3-month primary outcome data. Non-respondents were more likely to be male and more severely ill.

Conclusion: Delivery of T-CBT in an occupational context is feasible with evidence of potential effect. Larger-scale trials are warranted. These studies demand assertive outreach or telephone-based assessment strategies in order to maximize participant recruitment and follow-up.