Evaluating the clinical significance of responses by psychiatric inpatients to the mental health subscales of the SF-36

BackgroundThe Mental Health subscales of the Medical Outcomes Short Form Questionnaire (SF-36; [Ware, J.E., Snow, K.K., Kosinski, M., Gandek, B., 1993. SF-36 Health Survey: Manual and Interpretation Guide. Boston: The Health Institute, New England Medical Center]) are increasingly being used to evaluate treatment outcomes, but data to assess the clinical significance of changes are absent. The present study applied Jacobson and Truax's [Jacobson, N.S., Truax, P. 1991. Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology 59, 12–19] criteria for clinical significance to the mental health items of the SF-36.MethodAdmission and discharge data were collated from 1830 consecutive inpatients at a psychiatric hospital, using the SF-36, the Depression Anxiety Stress Scale, the Quality of Life Enjoyment and Satisfaction Questionnaire and the clinician-rated Health of the Nation Outcome Scale.ResultsAppropriate improvement cut-off scores for the mental health subscales of the SF-36 are reported, and significant differences were found between outcome groups according to clinically significant improvement.LimitationsClinical significance as a means of assessing outcome should be used with caution in inpatient settings, as further improvement is often expected upon discharge from the hospital.ConclusionsAssessing clinically significant improvement is an effective means of measuring treatment outcome in terms of quality of life and symptom improvement in psychiatric care.