Use of outcome measurements in clinical practice: How specific should one be?

OBJECTIVE

Progress feedback is often measured with generic instruments that measure common symptoms and generic aspects of functioning. The current study aims to explore the relative usefulness of disorder-specific measures. We hypothesized that disorder-specific instruments reveal more improvement than generic instruments and that the addition of disorder-specific instruments results in better treatment outcomes.

METHOD

We used a cohort of 3419 patients with a depression. As generic measures, we used the BSI or the symptoms distress subscale of the OQ-45. In 946 patients, a specific instrument, the IDS-SR, was added. We compared mean change scores and percentages of clinical significant change. In a matched case control design, we analyzed whether the additional use of the IDS-SR resulted in better treatment outcomes.

RESULTS

Mean change scores of both types of instruments were comparable. When comparing clinical significant change, agreement was moderate. We found better outcomes on the generic instruments when both a generic and a disorder-specific instrument were used.

CONCLUSION

In individual treatment of depression, generic and disorder-specific instruments are not interchangeable. The additional use of disorder-specific instruments provides a more complete picture of the patient's progress than the use of a generic instrument alone. Clinical or methodological significance of this article: In outcome management often rather generic instruments are used, that do not address the specific symptoms of the primary diagnosis of patients. In daily practice clinicians do not always use the feedback on treatment progress, when they perceive the feedback as not specific or relevant enough. The current study aims to explore the relative usefulness of measures that focus on symptoms that characterize the primary diagnosis of patients with a depression compared to the generic measures. We used a large cohort of existing data of patients of several mental health care organizations that share an application for outcome measurement. First, we compared outcomes of generic instruments and a disorder-specific instrument of a subsample of patients with a depressive disorder that completed both kinds of instruments. Next, we applied a matched case control design to control for differences between patients and analyzed whether the additional use of disorder-specific instruments predicted better outcomes. With this methodology, we tried to optimize both the methodological quality as well as the clinical significance of our research.