Measuring treatment outcome in patients with anxiety disorders: A comparison of the responsiveness of generic and disorder-specific instruments.

BACKGROUND

For routine outcome monitoring, generic (i.e., broad-based) and disorder-specific instruments are used to monitor patient progress. While disorder-specific instruments may be more sensitive to therapeutic change, generic measures can be applied more broadly and allow for an assessment of therapeutic change, irrespective of a specific anxiety disorder. Our goal was to investigate whether disorder-specific instruments for anxiety disorders are a valuable (or even necessary) addition to generic instruments for an appropriate assessment of treatment outcome in groups of patients.

METHODS

Data were collected from 2002 to 2013 from psychiatric outpatients in treatment for Social Phobia (SP; n = 834), Generalized Anxiety Disorder (GAD; n = 661), Panic Disorder (PD; n = 944), Obsessive-Compulsive Disorder (OCD; n = 460), and Posttraumatic Stress Disorder (PTSD; n = 691). Instruments used were the generic Brief Symptom Inventory (BSI), The Mood and Anxiety Symptoms Questionnaire (MASQ), and several disorder-specific instruments (e.g., Social Interaction Anxiety Scale, Social Phobia Scale, Panic Appraisal Inventory, etc.). Responsiveness (i.e., sensitivity to therapeutic change) was examined through correlational analyses, effect sizes (ES), and analysis of variance for repeated measures.

RESULTS

The MASQ appeared generally more responsive than the BSI, except for the BSI Anxiety subscale for PD. Disorder-specific measures equaled the MASQ and BSI in responsiveness. When statistically significant differences occurred, the ES was small.

DISCUSSION/

CONCLUSIONS

For most anxiety disorder groups (i.e., SP, PD and OCD), the MASQ or BSI was equally suited as disorder-specific instruments to detect change at group level. Exceptions are GAD and PTSD. These findings suggest limited incremental information value of disorder-specific instruments over the MASQ and BSI for measuring change.