A Meta-analysis of Horticultural Therapy Programs for Older Adults with Dementia

Background and objective: This study analyzed the effect size of each element to secure the expertise of horticulturaltherapy programs for older adults with dementia. Methods: This study conducted a meta-analysis to analyze the effectiveness of horticultural therapy programs for olderadults with dementia using 'horticulture' as a search term. To this end, 29 articles were selected and analyzed from a totalof 147 articles published between 2003 and 2022. Results: First, the overall effect size of horticultural therapy for older adults with dementia was .522, which is statisticallysignificant. This is considered a medium effect size according to Cohen's (1988) criteria for effect size. Second, the groupsize, a variable related to the number of subjects, showed the largest effect size when the group had 21-30 participants,and the number of sessions per week showed the largest effect size when the number of sessions was once a week,followed by twice a week, and so on. The effect size was largest when the total number of sessions was 21 or more, andwhen each session was conducted for 90-120 minutes. Conclusion: This study examined previous studies related to horticultural therapy programs for older adults with dementiathrough a meta-analysis and presented the results of a systematic effect size analysis. The significance of this study is thatit summarized the factors that have a large effect and quantified the effect sizes so that it can be used in varioushorticultural therapy programs for older adults with dementia.