Validating the Effectiveness of Forest Therapy Programs for Middle-Aged Korean Women: A Systematic Review and...

Background/Objectives: Middle-aged Korean women (aged 40-65 years) face compounded physiological and psychosocial health burdens, yet controlled evidence for non-pharmacological interventions in this population remains limited. This systematic review and meta-analysis aimed to quantify the effects of forest therapy on health-related outcomes in middle-aged Korean women and to identify program characteristics associated with differential therapeutic effects. Methods: Ten databases were searched for controlled studies published from January 2000 to February 2025 following PRISMA 2020 and PICOTS-SD criteria; only controlled studies conducted in Korea were included in the meta-analysis. Of 9563 records screened, 24 controlled Korean studies (RCT, n = 13; NRCT, n = 11; k = 128 effect sizes) met inclusion criteria. A three-level random-effects model with robust variance estimation (RVE) was used as the primary analysis. Results: The primary three-level RVE model, applied to 24 controlled Korean studies, yielded a pooled Hedges' g = 0.596 (95% CI: 0.432-0.760); a supplementary standard random-effects model yielded g = 0.542 (95% CI: 0.420-0.664). Substantial heterogeneity and potential publication bias were observed; overall evidence certainty was rated Low (GRADE). Conclusions: These findings provide preliminary, low-certainty evidence (overall GRADE: Low) that forest therapy may benefit middle-aged Korean women. They do not justify broad clinical or policy adoption at present. High-quality, independently conducted international RCTs and standardized trials outside Korea are required to confirm and generalize these findings.