Which Rating Scales are Regarded as ‘The Standard’ in Clinical Trials for Schizophrenia? A Critical Review

Background

This paper reviewed which rating scales past studies adopted as an outcome measure in clinical trials for schizophrenia, for which a consensus has been lacking.

Methods

A PubMed search was conducted using keywords ‘outcome’, ‘rating scales’, and ‘schizophrenia’. Studies published in 1999, 2004 and 2009 were examined to globally see if a trend has changed over the last decade.

Results

One-hundred fifty articles were inspected. As for psychopathology, the positive and negative syndrome scale (PANSS) has been by far the most frequently utilized scale (46%, 79%, and 78% in the respective years), followed by the brief psychiatric rating scale. Affective/anxiety symptoms have been only rarely recorded. Extrapyramidal symptoms have been assessed mostly with the Simpson Angus scale (SAS), more frequently in combination with the abnormal involuntary movement scale (AIMS) and Barnes akathisia scale (BARS) recently. Non-motor adverse effects have been typically reported without a usage of formal rating scales. Depending on the interest of investigation, other critical domains of the illness including functioning, cognition and subjective perspectives have been sporadically reported through the rating scales. The assessment scales were similarly utilized across the years, except for a numerical rise in scale utilization to rate the latter three domains in 2009.

Conclusions

The PANSS and set of AIMS, BARS and SAS, which are expected to take about 60 minutes to complete, are frequently utilized and may be regarded as a ‘standard’ in clinical trials for schizophrenia. Clinical implication of the findings and practical challenges with the existing scales are discussed.