[Can quality of life in psychotherapy be measured with clinician-ratings? A comparison of patient- and clinician-ratings using the SF-8]

Abstract

Objective: Quality of life is a major criterion of the outcome of psychotherapeutic interventions. The concept of quality of life emphasizes patient self-ratings. However, they can be burdensome or inappropriate in some cases. Therefore we have compared self-ratings and clinician-ratings of quality of life.

Methods: Self- and clinician-ratings of the SF-8 (1-week recall version) were measured from consecutive samples of 1 812 inpatients from eleven psychotherapeutic clinics at admission and at discharge six weeks later. A physical summary score (PSS) and a mental summary score (MSS) were calculated. Pearson product-moment correlations were used.

Results: Self- and clinician-ratings of the PSS correlate r=0.48 at admission and r=0.58 at discharge, of the MSS r=0.46 and r=0.51, respectively. Concerning single items we find the highest correlation for item 4 (bodily pain: r=0.53 and r=0.55), the lowest for item 6 (social functioning: r=0.26 and r=0.30). Change scores of the PSS correlate r=0.20, of the MSS r=0.32. Correlations differ between diagnostic groups: Correlations are low for patients with either schizophrenia (F2), depressive episode (F32) or personality disorder (F60-62), comparatively higher for patients with dysthymia. Comparing correlations across the 11 clinics reveals substantial differences, for the MSS ranging from r=0.38 to r=0.58 at admission and r=0.27 to r=0.68 at discharge.

Conclusion: Patient self-ratings of quality of life as a psychotherapeutic outcome measure using the SF-8 Health Survey could not be substituted by clinician-ratings, they should be used as complements.