A Systematic Mapping Review of 525 Randomised Controlled Trials on Pharmacological and Non-pharmacological Interventions for People Living With Dementia and Their Formal and Informal Carers in Chinese Communities

Aligned with the World Health Organization's call for enhanced dementia research to inform national strategies, this systematic mapping review identifies critical gaps in the evidence base for Chinese populations. Representing over 20% of people living with dementia globally, this group remains underrepresented in the Western-centric research that currently guides best practices. This is the first study that comprehensively reviews evidence on dementia-related interventions trialled among participants identified as Chinese worldwide across both Chinese and English literature. It addresses critical gaps in previous Anglo-centric reviews by capturing culturally specific interventions and assessing the evolving evidence landscape for Chinese population.

Following PRISMA guidelines, we systematically searched two widely used Chinese databases (China National Knowledge Infrastructure, Wanfang Data) and 12 English bibliographical databases (MEDLINE, EMBASE, PsycINFO, CINAHL Plus, Global Health, WHO Global Index Medicus, Virtual Health Library, Cochrane CENTRAL, Social Care Online, BASE, MODEM Toolkit, Cochrane Database of Systematic Reviews) to identify randomised controlled trials (RCTs) published between 2008 and 2020 (registered on PROSPERO: CRD42019134135). Dual-language teams employed culturally sensitive strategies to maximise coverage of regionally prevalent interventions. Risk of bias was assessed using version two of the Cochrane risk-of-bias tool for randomised trials. A narrative approach was used to review and assess the current landscape of dementia intervention research in Chinese communities.

We identified 183,277 records across Chinese and English databases and included 525 unique RCTs for synthesis (93% published in Chinese). The most commonly studied interventions were multicomponent interventions (35.2%), followed by pharmacological (29.5%), non-pharmacological (18.3%), and traditional Chinese medicine (TCM; 14.5%) interventions. 62.7% of multicomponent RCTs were those combining TCM with Western drugs. Cognitive outcomes were measured in 86.9% of RCTs and functional outcomes in 60.2%, while only 3% evaluated quality of life (QoL) and 1% carer-related outcomes. Most trials (91.8%) were hospital-based. Over 80% of included RCTs were assessed as having overall 'some concerns'.

Despite rapid growth of dementia intervention research in Chinese communities, evidence remains skewed towards hospital-based trials conducted predominantly in mainland China, with a focus on cognitive and functional outcome. High-quality evidence is urgently needed to rebalance research priorities and address critical knowledge gaps in improving QoL, carer support, and community-based interventions. Our finding that most trials were published in Chinese involving TCM illustrates the value of integrating non-English literature in global evidence synthesis, especially for identifying culturally specific interventions common in lower- and middle-income countries.