Lifestyle interventions for dementia prevention in Low- and Middle-Income Countries: A systematic review

By 2050, two-thirds of people with dementia will live in Low- and Middle-Income Countries (LMICs). Efforts to adapt and test multi-modal prevention interventions focusing on lifestyle changes for people at risk of dementia are being developed predominantly in higher income countries, for people with and without cognitive symptoms. However, there is evidence that needs may differ between these groups. We systematically reviewed Randomized Controlled Trials (RCTs) evaluating non-pharmacological interventions in individuals with Mild Cognitive Impairment (MCI) and Subjective Cognitive Decline (SCC) in LMICs. We analysed study quality using the Mixed Methods Assessment Tool (MMAT), meta-analysed and synthesized evidence. We included 25 RCTs, from six countries (most in China, n=17), involving 1304 participants. Across the 15 studies for which there was sufficient data to meta-analyse, we found significant positive effects on cognitive outcomes favouring interventions [1.49 (standardised mean difference, 95% Confidence Interval= 1.06-1.93)]. There was significant publication bias. Using an a priori standard framework, we classified interventions into exercise, multidomain, and arts/creative expression. Group exercise [1.67, 1.24-2.11, n=8]. and multidomain [1.22, 0.22-2.21, n=5] had replicated evidence of effectiveness. There was insufficient data to meta-analyse the creative arts category. We identified one high quality, multi-modal intervention, which combined Chinese mind-body exercises and health education, reporting a positive outcome. The first robust dementia prevention trials are underway in LMICs, evaluating effectiveness of models developed in higher income countries. We propose greater consideration and investment in development of interventions that account for specific LMIC contexts from the outset, so they are acceptable and used by local services. Highlights ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement RE was supported by the Agencia Nacional de Investigacion y Desarrollo through Becas Chile, Folio: 72220036. CM-C was supported by the ANID-FONDECYT 1191726; the ANID-Millennium Science Initiative Program ICS2019\_024 and ICS13\_005. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All references used were obtained from online data bases.