Measuring social functioning with the personal and social performance scale in patients with acute symptoms of schizophrenia: interpretation of results of a pooled analysis of three Phase III trials of paliperidone extended-release tablets.
Patrick DL., Burns T., Morosini P., Gagnon DD., Rothman M., Adriaenssen I.
BACKGROUND: The safety and efficacy of paliperidone extended-release tablets (paliperidone ER) in patients with acute symptoms of schizophrenia have been described in 3 randomized, double-blind, 6-week, placebo-controlled, fixed-dose, Phase III clinical trials. The validity and reliability of the Personal and Social Performance (PSP) scale, both in patients with acute symptoms of schizophrenia and those with stabilized symptoms, have also been reported. OBJECTIVE: The aim of this work was to estimate the treatment benefit of paliperidone ER compared with placebo in terms of improvements in personal and social functioning as measured by the PSP scale in 3 controlled clinical trials. METHODS: Data were derived from 3 paliperidone ER multicenter Phase III pivotal studies of patients with acute symptoms of schizophrenia. Each study included a randomized, double-blind, placebo- and active-controlled, parallel-group, 6-week treatment period with an open-label extension of paliperidone ER treatment. Patients were randomized to receive paliperidone ER, olanzapine 10 mg, or placebo once daily. Paliperidone ER doses were 3, 9, and 15 mg/d in 1 study; 6, 9, and 12 mg/d in another; and 6 and 12 mg/d in the third. Collectively, 1306 intent-to-treat patients received placebo or paliperidone ER in these 3 trials. Most (61.7%) were white; 21.6% were black, 8.8% were Asian, and 7.9% were of another race. The mean age ranged from 36.3 to 39.4 years across treatment groups. Multiple analyses were applied to PSP data (for which higher scores indicate better personal and social functioning) from these paliperidone ER studies: between-group minimum important difference (MID) estimates; responder analyses; between-group cumulative frequency comparisons of PSP change from baseline to end point; and number-needed-to-treat (NNT) estimates. RESULTS: Standardized differences and effect sizes between paliperidone ER and placebo in PSP mean change from baseline to end point ranged from 0.52 to 0.85 for all paliperidone ER doses. Observed between-group differences (paliperidone ER minus placebo) in PSP mean change from baseline to end point exceeded the between-group MID of 7 points at all paliperidone ER doses. The percentage of patients achieving at least one 10-point category improvement in the PSP was higher with all paliperidone ER doses (range, 49.6%-63.6%) than placebo (33.1%) (P < 0.005). Across the distribution of all possible PSP scores, the percentage of patients achieving any level of change appeared to be greater for paliperidone ER than for placebo at all doses. Derived NNTs for improved personal and social functioning based on paliperidone ER trials ranged from 3.3 to 6.1. The improvement in personal and social functioning achieved by patients receiving paliperidone ER during the double-blind studies was maintained throughout the 52-week, open-label extension studies, as assessed using multiple definitions of response; subjects in the placebo arm during doubleblind treatment appeared to achieve and maintain improved functioning when switched to paliperidone ER for the extension studies. CONCLUSION: These results suggest that paliperidone ER had a meaningful treatment benefit with respect to improving personal and social functioning in these patients with acute symptoms of schizophrenia.