Effectiveness of virtual reality-based nature interventions in promoting mental health outcomes among older adults with cognitive impairment: a systematic review and meta-regression analysis.

内容摘要

This systematic review and meta-regression evaluated virtual reality‑based nature interventions for older adults with cognitive impairment. Following PRISMA 2020 and a registered PROSPERO protocol (January 2000-December 2025), we identified randomised controlled trials from nine databases and two registries. Eligible interventions used simulated nature as the primary therapeutic component. Random‑effects models pooled standardised mean differences (SMDs) and risk ratios (RRs). Twenty‑four RCTs (N = 1,534) were included. VR nature interventions significantly improved depression (SMD = -1.17), anxiety (-1.45), stress/distress (-1.38), apathy (-1.33), loneliness (-1.32), agitation (-1.69), and overall neuropsychiatric symptoms (-1.34). Quality of life improved (mental health‑related SMD = 1.26; global SMD = 1.14; mood/positive affect SMD = 1.18). Sleep quality improved (RR = 3.44). Engagement favoured VR (SMD = 1.07), while physiological stress markers showed mixed effects (SMD = -0.72). Dichotomous outcomes had no heterogeneity (I² = 0%); continuous outcomes showed substantial heterogeneity (I² > 90%). Meta‑regression found a modest positive association between intervention duration and effect size (β = 0.01/week). VR‑based nature interventions may improve mental health and quality of life in older adults with cognitive impairment. However, large effect sizes, high heterogeneity, and potential small‑study effects warrant cautious interpretation. What is already known about this topic: (1) Neuropsychiatric symptoms, such as depression, anxiety, apathy, agitation, and loneliness, are highly prevalent in older adults with cognitive impairment and are associated with increased caregiver burden, functional decline, and limited response to pharmacological treatments. (2) Exposure to natural environments has established mental health benefits; however, physical access is frequently restricted by mobility limitations, institutional settings, and safety concerns, prompting interest in simulated alternatives. (3) Prior narrative reviews have documented variability in virtual reality – based nature interventions according to immersion level and content characteristics; however, no comprehensive quantitative synthesis has specifically focused on randomised evidence in older adults with cognitive impairment. What this topic adds: (1) This systematic review and meta-regression of 24 randomised controlled trials (N = 1,534) demonstrated large, consistent improvements across multiple domains, including depression (SMD −1.17), anxiety (SMD −1.45), agitation (SMD −1.69), loneliness (SMD −1.32), and mental health – related quality of life (SMD 1.26), with high engagement (SMD 1.07). (2) Meta-regression identified intervention duration as a modest positive moderator (β≈+0.01 per week) of effect size, while revealing substantial heterogeneity (I2 > 90% for continuous outcomes) and small-study effects that warrant cautious interpretation of the results. (3) The analysis provides the first pooled estimates of feasibility, safety, and evidence certainty (GRADE) for this population, offering actionable guidance for standardised content libraries, supervised delivery protocols, and future multicentre trials with longer follow-up.