Outcome measurement in pharmacological trials: validity of the Routine Assessment of Patient Progress (RAPP).

The assessment of outcomes after treatment with antipsychotic medication is fundamental to clinical care and research. The Routine Assessment of Patient Progress (RAPP) is a reliable multidimensional scale that employs nurses' ratings of symptoms and functioning in psychiatric inpatients. The present study sought to extend validity evidence for the RAPP by examining its ability to reflect changes associated with treatment by antipsychotic medications. The use of a different sample in this study also provided the opportunity to replicate earlier validity data collected on the original set of patients. Ninety-seven separate trials were conducted, involving 65 consecutive admissions to a unit that specializes in the assessment and treatment of patients with long standing severe psychiatric disorders. The RAPP, along with the Positive and Negative Syndrome Scale and global measures of severity, were administered at baseline and at the end of each trial. Both factor scores and clinically-derived subscales were analysed for sensitivity to change. Patients were globally rated as improved, unchanged or worsened at the end of the medication trial. Results indicated that the RAPP factor, clinical scale and total scores compared favourably to other outcome measures in patients rated as improved or worse. In patients rated as unchanged, RAPP scores displayed significantly less change than did the PANSS scores. These findings support the validity of the RAPP as an outcome measure in treatment trials.