Efficacy and safety of commercial Chinese polyherbal preparations combined with biomedicine for elderly patients with primary insomnia: a systematic review and meta-analysis of randomized controlled trials

Abstract

The prevalence of primary insomnia among the elderly is steadily increasing; however, robust evidence supporting the efficacy and safety of combining commercial Chinese polyherbal preparations (CCPPs) with biomedicine therapy remains insufficient. This study aimed to systematically evaluate the efficacy and safety of CCPPs combined with biomedicine versus biomedicine therapy for primary insomnia in elderly patients, and to assess the certainty of the evidence via the GRADE framework and P-curve analysis. Seven biomedical databases were searched (before November 2025) for randomized controlled trials (RCTs) involving elderly patients with primary insomnia. Risk of bias was assessed using Cochrane RoB 2 by two researchers independently. Meta-analysis was performed using R software. Outcomes included Pittsburgh Sleep Quality Index (PSQI), total clinical effectiveness rate, Sleep Dysfunction Rating Scale (SDRS), and adverse events. Robustness was evaluated via sensitivity, subgroup, and P-curve analyses. Meta-analysis suggested that combined therapy was associated with a lower PSQI score (MD = −2.09, 95% CI -2.62 to −1.57) and higher total clinical effectiveness rate (RR = 1.21, 95% CI 1.15–1.27) relative to monotherapy. The combination group also showed a lower risk of adverse events (RR = 0.47, 95% CI 0.36–0.61). However, P-curve analysis revealed notable discrepancies across outcomes: PSQI exhibited sufficient evidential value (Power = 99%), whereas the total clinical effectiveness rate lacked adequate evidential value (Power = 9%), implying potential publication bias. Subgroup analyses showed that heterogeneity decreased within the subgroup of patients with disease duration <1 year, although the between-subgroup difference did not reach statistical significance. The certainty of evidence was rated as “Moderate” for adverse events but “Low” to “Very Low” for efficacy outcomes. In elderly patients with primary insomnia, combined treatment of CCPPs and biomedicine may help improve sleep quality and may reduce adverse events reported in clinical trials. However, due to methodological limitations, high heterogeneity and potential publication bias among the included trials, the certainty of the available evidence remains limited. Given insufficient evidential value, the reliability of the total clinical effectiveness rate is questionable, and clinicians should place greater emphasis on outcomes assessed using validated scales such as the Pittsburgh Sleep Quality Index (PSQI). Further large-scale, multicenter, double-blind, placebo-controlled randomized controlled trials (RCTs) are needed to further verify these preliminary findings. https://www.crd.york.ac.uk/PROSPERO/view/CRD420251186213 , identifier: CRD420251186213.