Statistical methods for measuring outcomes.

This issue of the journal concerns promotion of the routine use of outcome measures in clinical practice; the purpose of this particular article, however, is to warn care providers to think very very carefully before routinely using such measures. Just what are the benefits of their use? What are the outcome measures intended to demonstrate? In order to try to convince the reader that there might be real difficulties in the interpretation of the results, the main body of the paper concentrates on the difficulties in the interpretation of data from a structured research project that has been specifically designed to evaluate an innovation in mental health care provision. The difficulties of interpreting haphazardly collected data as part of routine clinical or administrative practice will be far greater. One of the main purposes of an evaluative exercise is comparison: which approach to service provision is the better? If care providers really want to be involved in mental health service evaluation then their time would be much better spent in taking part in a large multicentre trial.