Attitude and influencing factors of patients with schizophrenia toward long-acting injections: A community-based cross-sectional investigation in China

Characteristics of patients with schizophrenia switching from oral antipsychotics to once-monthly paliperidone palmitate (PP1M): a systematic review

BACKGROUND

The utilization of once-monthly paliperidone palmitate (PP1M) in schizophrenia treatment has increased due to its enhanced adherence and convenience. However, there is limited evidence on patient characteristics that may influence treatment outcomes when switching from oral antipsychotics (OAPs) to PP1M therapy. This systematic review aims to identify such patient characteristics and explore potential beneficial factors to aid healthcare professionals in clinical practice.

METHODS

A systematic literature search was conducted in the PubMed, Embase, and Cochrane Library databases up to July 19, 2022. Studies related to patients with schizophrenia who had been previously treated with OAPs and switched to PP1M were identified and included. Outcomes included the Positive and Negative Syndrome Scale (PANSS) total score, the clinical Global Impressions - Severity (CGI-S) score, the Personal and Social Performance (PSP) total score, and hospitalisation rate. Data were independently extracted and analysed. The results were presented through a narrative synthesis.

RESULTS

Eleven studies with a total of 4150 patients were included, identifying nine potential characteristics. The most commonly reported characteristics was patient's prior treatment with OAPs, followed by the stage of disease, duration of illness (DI), ethnicity, reason for switching to PP1M, history of hospitalisation, time of start injection of PP1M, the PANSS and PSP total score at baseline. Patients in the acute stage, with a shorter DI, a less than 1-week time interval to PP1M injection, and a lower PANSS total score at baseline may have a trend on providing better improvements on PANSS total score. Acute stage and shorter DI also showed potential trends in reducing CGI-S score. Early initiation of PP1M, switching for reasons other than lack of efficacy, and a higher PSP score at baseline exhibited potential trends towards better PSP total score improvements.

CONCLUSION

Our findings may suggest that patients in acute stage, with a shorter duration of illness, with early initiation of PP1M injection, and lower PANSS or PSP scores may trend towards better clinical results when transitioning to PP1M from OAPs. Further research is necessary to validate these potential associations and identify any unexplored characteristics. Such investigations are crucial for providing comprehensive clinical recommendations and informing treatment strategies in this context.

Cost-utility analysis of using paliperidone palmitate in schizophrenia in China

Objective: Long-acting injections (LAIs) of paliperidone palmitate have been shown to improve medication adherence and relieve psychotic symptoms. However, the specific cost-utility analysis of these LAIs in schizophrenia in China remains unclear. Methods: A multi-state Markov model was constructed to simulate the economic outcomes of patients with schizophrenia in China who received paliperidone palmitate 1-month formulation (PP1M), paliperidone palmitate 3-month formulation (PP3M), and paliperidone extended-release (ER). A cost-utility analysis was conducted, mostly derived from published literature and clinical databases. All costs and utilities were discounted at a rate of 5% per annum. The primary outcome measure was the incremental cost-effectiveness ratios (ICERs). A series of sensitivity analyses were also applied. Results: After 20 years, compared to ER, using PP1M resulted in an increased discounted cost from $36,252.59 to $43,207.28. This increased cost was associated with a gain in quality-adjusted life years (QALYs) from 8.60 to 9.45. As a result, the ICER for PP1M was estimated to be $8,247.46/QALY, which was lower than the willingness-to-pay (WTP) threshold of $12,756.55/QALY. When using PP3M instead of ER, the incremental cost was $768.81 and the incremental utility was 0.88 QALYs, projecting an ICER of $873.13/QALY, which was also lower than the WTP threshold of $12,756.55/QALY. The univariate sensitivity analysis showed that the costs of PP1M, PP3M, and ER had the greatest impact on ICERs. The probability sensitivity analysis (PSA) revealed that when the WTP thresholds were $12,756.55/QALY, the probability of PP1M and PP3M being cost-effective was 59.2% and 66.0%, respectively. Conclusion: From the Chinese healthcare system perspective, PP3M and PP1M are both more cost-effective compared to ER, and PP3M has notable cost-utility advantages over PP1M.