Abstract
Objectives: In recent years schizophrenia trials suffer from diminishing differences in effects of drug and placebo treatment even for established antipsychotics [1]. While there are multiple factors which can lead to difficulties in differentiating between placebo and drug treatment, one of them could be that the available rating scales, e.g. Positive and Negative Syndrome Scale (PANSS) [2] are not optimal for measuring the effect of drug treatment. The goal of this study was to analyse the responses of the individual items of PANSS and item subscales to drug and placebo treatment in order to find the ones which are most sensitive to differentiate between placebo and drug effect.
Methods: We analysed data from seven clinical trials of different antipsychotics. “Mini-PANSS” scales consisting of the most sensitive items identified in exploratory analysis were created and analysed statistically. The power of these scales to show a statistically significant difference between the placebo and drug treatment was then compared with the power of total PANSS and its positive, negative and general psychopathology subscales. Additionally, pharmacokinetic-pharmacodynamic analysis was performed in order to determine which of these (sub)scales shows the highest drug effect on top of the placebo effect.
Results: All 30 items of the PANSS scale show a therapeutic drug effect. Mini-PANSS scales consisting of items with the largest drug treatment response are somewhat better in differentiating between placebo and drug treatment than the total PANSS. However, the difference between the tested mini-PANSS scales and total PANSS is generally very small.
Conclusions: None of the studied scales can replace PANSS total in the analysis of primary endpoints.
References:
[1] Kemp AS, Schooler NR, Kalali AH, Alphs L, Anand R, Awad G, et al. What is causing the reduced drug-placebo difference in recent schizophrenia clinical trials and what can be done about it? Schizophrenia Bulletin. 2010;36(3):504-9.
[2] Kay SR, Fiszbein A, Opler LA. The Positive and Negative Syndrom Scale (PANSS) for schizophrenia. Schizophrenia Bulletin. 1987;13(2):261-76.
Methods: We analysed data from seven clinical trials of different antipsychotics. “Mini-PANSS” scales consisting of the most sensitive items identified in exploratory analysis were created and analysed statistically. The power of these scales to show a statistically significant difference between the placebo and drug treatment was then compared with the power of total PANSS and its positive, negative and general psychopathology subscales. Additionally, pharmacokinetic-pharmacodynamic analysis was performed in order to determine which of these (sub)scales shows the highest drug effect on top of the placebo effect.
Results: All 30 items of the PANSS scale show a therapeutic drug effect. Mini-PANSS scales consisting of items with the largest drug treatment response are somewhat better in differentiating between placebo and drug treatment than the total PANSS. However, the difference between the tested mini-PANSS scales and total PANSS is generally very small.
Conclusions: None of the studied scales can replace PANSS total in the analysis of primary endpoints.
References:
[1] Kemp AS, Schooler NR, Kalali AH, Alphs L, Anand R, Awad G, et al. What is causing the reduced drug-placebo difference in recent schizophrenia clinical trials and what can be done about it? Schizophrenia Bulletin. 2010;36(3):504-9.
[2] Kay SR, Fiszbein A, Opler LA. The Positive and Negative Syndrom Scale (PANSS) for schizophrenia. Schizophrenia Bulletin. 1987;13(2):261-76.
| Original language | English |
|---|---|
| Article number | 2513 |
| Pages (from-to) | 386-386 |
| Number of pages | 1 |
| Journal | PAGE : Abstracts of the Annual Meeting of the Population Approach Group in Europe |
| Issue number | 2012 |
| Publication status | Published - 2012 |