Sensitivity to change of the Beck Depression Inventory versus the Inventory of Depressive Symptoms.

Background: In a previous study which made a comparison between disorder-specific and generic instruments to assess outcome of treatments for depression, the Beck Depression Inventory, Second Edition (BDI-II) seemed to be more sensitive to change than the Inventory of Depressive Symptoms- Self Rating (IDS-SR).

Methods: A set with longitudinal data from Routine Outcome Monitoring (n=144) were analyzed with multilevel models with random intercepts. The sensitivity to change of two disorder-specific instruments, the BDI-II and the IDS-SR, were compared head to head.

Results: The BDI-II was more sensitive to change when measuring treatment outcome compared to the IDS-SR. The BDI-II decreases significantly more over time than the IDS-SR: the average decrease per week for the IDS-SR is -.012 (95%CI -0.015, -0.009) and for the BDI-II it is -.017 (95%CI -0.021, -0.014).

Limitations: Conclusions can only be preliminary due to a small sample size.

Conclusions: Treatment outcomes measured with questionnaires may differ depending on the degree of sensitivity to change of the instruments.