Effectiveness of horticultural therapy in people with dementia: A quantitative systematic review

Aims and objectives To evaluate the effectiveness of horticultural therapy on cognitive function, agitation, positive emotion and engagement in people with dementia. Background The number of people with dementia is increasing rapidly, and nonpharmacological interventions such as horticultural therapy have been recommended as the first choice for these patients. Horticultural therapy involves participatory and ornamental horticultural therapy. Many original studies have examined the effectiveness of horticultural therapy in the last two decades. However, these studies vary in types of interventions, outcomes and measurement. Design A quantitative systematic review and meta-analysis. Methods This systematic review was conducted under PRISMA guidelines. Randomised controlled trials (RCTs) and quasi-experimental studies involving horticultural therapy for people with dementia were included. Risk of bias was assessed by the Cochrane's and Joanna Briggs Institute's tool. Reference lists and a relevant journal were searched. Meta-analyses were conducted using RevMan 5.3. PubMed, CINAHL, Embase, BIOSIS Previews, Web of Science Core Collection, China National Knowledge Infrastructure, Wanfang, SinoMed, Cochrane Library and ProQuest Health & Medical Complete were searched. Studies from database inception to 1 July 2019 were included. Results This systematic review included 14 studies (4 RCTs and 10 quasi-experimental studies) involving 411 people with dementia. The results of meta-analyses indicated that significant differences were found in the effectiveness of participatory horticultural therapy on total score of cognitive function, agitation, positive emotion and engagement, but not in the effectiveness of ornamental horticultural activities on agitation and positive emotion. Conclusions The existing evidence supports the effectiveness of participatory horticultural therapy on cognitive function, agitation, positive emotion and engagement. Future high-quality original studies are needed to draw more robust conclusions. Relevance to clinical practice The results support the use of participatory horticultural therapy for improving cognitive function, agitation, positive emotion and engagement of people with dementia.