Systematic Review on the Positive Mental Health Impact of Older Adults Participation in Horticultural Activities in Long Term Care Facilities

Abstract

The present research study focuses on exploring the effects of horticultural activities on the health outcomes of residents of long-term care facilities (LTCFs). The study utilizes evidence-based nursing and a systematic literature review. A search for relevant articles was conducted on databases such as PubMed, EMBASE, CINAHL, PsycINFO, and Cochrane. Randomized controlled trials in English and Chinese were included in the analysis, with two researchers independently evaluating the selected articles. The synthesis of results revealed that horticultural activities for residents of LTCFs had positive effects on physical aspects, such as increasing physical agility and aerobic endurance. Moreover, they had positive influences including happiness, positive mental health. In terms of social aspects, horticultural activities for older adults helped reduce aggressive behaviors, promoted goal-oriented living, and enhanced quality of life. Evidence of the impact of horticultural activities on the positive mental health of residents of LTCFs is relatively scarce compared to community-dwelling older adults, where psychological states are often studied in negative contexts. It has been suggested that LTCFs should integrate horticultural activities into their regular programs to foster positive mental health outcomes. Horticultural activities show promise in promoting positive mental health among residents of LTCFs and warrant further exploration.

1. Introduction

People’s average life expectancy has increased. By 2050, the number of people aged 60 and above is expected to exceed two billion. There are currently 12.5 million people aged 80 or above worldwide [1].

At the beginning of the year 2023, the population of older adults in Taiwan had reached 4,107,315; it is estimated that by the year 2026, the population of older adults in Taiwan will exceed 20% of the total population, with 3,154,519 people aged 80 or above [2]. Older adults who are unable to live independently at home due to health problems may choose to live in institutions. However, a survey conducted in Taiwan found that the majority of older adults still prefer to live with their children, and the percentage of those who choose to live in LTCFs has remained low. The actual proportion of older adults who live in such institutions is only about 3% [3]. However, when older adults move into LTCFs, they may experience negative physiological and psychological effects due to leaving their familiar home environment. The literature also suggests that depression is a common health problem among older adults in LTCFs [4]. In recent years, there has been increasing acknowledgement of the important role mental health plays in achieving global development goals, as illustrated by the inclusion of mental health in the Sustainable Development Goals [5]. Therefore, the physiological and psychological healthcare of older adults in LTCFs requires more attention. Complementary and Alternative Medicine (CAM) has been analyzed through evidence-based medicine and found to have beneficial effects on the health of older adults. In clinical practice, drug treatments and alternative therapies are commonly used interchangeably to treat diseases or aid in physical recovery. In clinical practice, drug treatments and alternative therapies are commonly used interchangeably to treat diseases or aid in physical recovery [6]. The World Health Organization (WHO) defines health as a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity [7]. In addition to physical healthcare, maintaining and establishing interpersonal relationships is important for older adults in LTCFs who have left their familiar home environment. Horticultural therapy is one of the integrative forms of therapy that involves the mind, body, and spirit in interpersonal activities. In the 21st century, horticultural therapy has become a leisure activity that interests older adults. Any plant-related materials can be organized into gardening activities, such as park landscaping. For individuals with impaired activities of daily living but who maintain clear awareness and physical mobility, indoor tabletop horticultural activities can be arranged. During the activity, people can actively interact with each other, which helps improve memory, cognitive abilities, motivation, speech skills, and socialization [8]. At the same time, plant materials are easily accessible, and older adults can be stimulated and motivated by interacting with others during the horticultural therapy process, which can lead to health promotion benefits. Horticultural therapy is effective because it has three therapeutic mechanisms: “interaction”, “action”, and “reaction”. “Interaction”: individuals in the plant world are not threatened or discriminated against and have the opportunity to establish new relationships, such as social interaction between horticultural activity leaders and individuals, individuals and individuals, and individuals and plants, or design horticultural activities to achieve goals [9,10,11]. “Action”: During the horticultural therapy process, individuals invest their body, emotions, and mind, increasing their potential for positive emotions. By participating in practical actions, individuals can complete tasks independently or work together and support each other, experiencing learning and the exchange of ideas while also achieving social interaction. The natural characteristics of horticultural activities can increase individual attention. “Reaction”: during the horticultural therapy process, individuals can express their personal feelings and reactions [12].

Horticultural activities can help individuals relax their minds. In the aging society, healthcare providers for older adults are designing activities that utilize horticultural therapy’s three important factors of interaction, action, and reaction to assist older adults in LTCFs to achieve health-related outcomes [12,13].

The effectiveness of these activities requires further investigation. There have been many systematic reviews and meta-analyses of horticultural therapy in terms of promoting health in older adults, which have shown benefits such as reducing agitation in older adult individuals with dementia [13,14]. Gardening activities have been shown to be beneficial in improving depressive symptoms in older adults [15]. The design of activities that bring dementia patients closer to parks and gardens has been found to be effective in treating and maintaining symptoms, with the greatest benefits being seen in terms of reduced agitation, forgetfulness, and depression, improved mood and cognitive function, and reduced stress and medication use [16,17]. Promoting emotional function and well-being among older adults can improve their primary social function and quality of life and has the potential to benefit their physical and mental health. Gardening therapy is a safe non-pharmacological treatment approach and has been found to be effective, in terms of the experience of healthcare professionals, for elderly individuals with cancer, dementia, and frailty, among other conditions [18]. Therefore, horticultural therapy has been proven to be effective and beneficial in promoting emotional function and well-being, improving major social function and quality of life in older adults. Welling refers to the overall state of a person’s physical, mental, and emotional health. In this systematic literature review, positive mental health in older adults is defined to encompass a sense of integrity across one’s lifespan, self-management, and a sense of purpose in life.

It has the potential to improve both physical and psychological health and is a safe non-pharmacological treatment measure. This article will further discuss the health benefits of horticultural therapy for older adults in LTCFs through empirical nursing and systematic literature reviews, through which it is evident that horticultural activities can promote positive mental health in institutionalized older adults. The results of the study will be compiled and presented as a reference for the design of activities in LTCFs and hypotheses of horticultural activities that suggest enhanced positive mental health in LTCFs. The research question (RQ) of this article relates to: the impact of horticultural therapy or horticultural activities on the positive mental health of older adults without cognitive impairments in LTCFs. This paper follows a systematic literature review approach and sequentially outlines the materials and methods, search strategy, keywords, nursing evidence-based approach, inclusion criteria and exclusion criteria, databases and information sources, quality assessment using the Jadad scale, results, discussion, and conclusions. It will culminate in a conclusion while also offering practical applications.

2. Materials and Methods

This systematic review strictly followed the preferred reporting items for systematic reviews [19,20,21]. This systematic literature review obtained IRB approval (No. 2022A004) primarily for the purpose of conducting a second stage of qualitative research based on the results from the initial systematic literature review.

This study adopted a systematic literature review approach that included Chinese and English RCTs and quasi-experimental studies. The objective was to examine the impact of horticultural activities on the health of older adults in LTCFs. No amendments have been made to the PROSPERO platform of this systematic review.

2.1. Search Strategy

2.1.1. Keywords

Using MeSH terms and free terms were used: (horticultural therapy OR horticultural activity OR elderly in LTCFs OR aged in LTCFs OR older adults in LTCFs). The original published articles were selected based on the types of horticultural therapy or horticultural activities, duration, and interval.

2.1.2. Nursing Evidence-Based Approach

The nursing evidence-based approach included the following parameters: population, intervention, comparison of interventions, and outcome (PICO), as shown in

Table 1. What is impact of horticultural therapy on the health of older adult residents in LTCFs?

P = older adult living in long term care facility

I = horticultural therapy (horticultural activity)

C = routine of daily life

O = health (physical, mental, cognition and social relationships).

S = RCTs.

. (1) Population: older adults aged 65 years and above who are residing in LTCFs. (2) Intervention: horticultural therapy or horticultural activity. (3) Comparison of intervention: routine of daily life. (4) Outcome: physical function including ADL, muscle strength, agility, flexibility, balance, and aerobic endurance; psychological health including depression, anxiety, social function, well-being, and quality of life; and social interaction. (5) Study design: RCTs.

2.1.3. Keywords and PICO

Keywords were identified using PICO and the keywords syntax to retrieve records from online databases, with the syntax constructed to include horticultural activities. The keywords included were as follows: older adult, aged, horticultural therapy, horticultural activity, long-term care facility.

2.1.4. Inclusion Criteria and Exclusion Criteria

The inclusion criteria were as follows: (1) individuals aged 65 and above (including those 65 years old) (2) residing in LTCFs for a minimum of three months (including three months) with (3) clear consciousness and the ability to communicate and express opinions who (4) consented to participate in this study. The exclusion criteria were as follows: (1) unavailability of full-text articles; (2) overlapping publications; (3) intervention in the experimental group was HT combined with other interventions; and (4) articles published in languages other than English and Chinese.

2.1.5. Databases and Information Sources

The project selected a total of five databases in Chinese and English, including Pubmed, CINAHL, Ovid MEDLINE, the National Digital Library of Theses and Dissertations in Taiwan, and the Airiti Library. The search process is shown in

Table 2. Literature search history.

Pubmed

(older adult in LTCFs) AND (horticultural therapy)

(“Horticultural Therapy”[MeSH]) AND “Aged”[MeSH]

(older in LTCFs) AND (horticultural activity)

CINAHL

older adult in LTCFs AND horticultural therapy OR horticultural activity

Older adults in LTCFs AND horticultural therapy OR horticultural activity

elderly in LTCFs AND horticultural therapy

Ovid MEDLINE

(“horticultural therapy”) OR (therapeutic therapy) OR (“horticultural activity”) AND (aged) OR (older adult in LTCFs) OR (older adults in LTCFs)

National Digital Library of Theses and Dissertations in Taiwan

(“older adult in LTCFs” and “horticultural therapy” or “horticultural activity”).kw, ab, ti/yr = “103–110”

(“older adults in LTCFs” and “horticultural therapy” or “horticultural activity”).kw, ab, ti/yr = “103–110”

Airiti Library

Elderly in LTCFs + Horticultural therapy

Elderly in LTCFs + Horticultural activity

Older adults in LTCFs + Horticultural therapy

Older adults in LTCFs + Horticultural activity

.

2.1.6. Filters

In the review, no filters by language, country, or type of document were applied. This timeframe included any published papers at any time in the years prior to 1 July 2022.

2.1.7. Teamwork

The screening process was initially conducted by two reviewers who searched for relevant studies using keywords and examined the titles and abstracts to filter out research studies related to the main topic of this project.

2.1.8. Study Selection

It was decided that the selection of papers would be restricted to research articles, and through screening them by titles and abstracts, different elements (e.g., moderate to severe dementia, depression, anxiety) were accordingly removed.

A full-text search was then performed, with each article read one by one and a detailed search strategy provided. In the results section of each article, the number of reasons for inclusion or exclusion of systematic literature reviews that were searched, screened, included, or excluded was identified, as presented in the PRISMA flowchart in Figure 1 [22]. If there were differences of opinion during the process, a consensus was reached after coordinated discussion.

The selected articles were sorted according to research objectives and data extraction, including author, year, study design, study population, intervention providers, intervention measures, and effectiveness. A total of 735 articles were obtained through database retrieval, which was initially screened down to 37 articles. The reasons for excluding certain articles were primarily centered around focusing on positive mental health following participation in horticultural activities or therapy. This excludes individuals with moderate to severe dementia and negative mental health conditions such as depression and anxiety. After full-text browsing, the number of articles that met the inclusion criteria was 4, all of which were included in the systematic literature review.

2.1.9. Quality Assessment Using the Jadad Scale

Article quality was assessed using the Jadad scale [23]. There are 5 evaluation items, with each item given a score of 1 or 0 (yes = 1 no = 0), as shown in

Table 3. Quality assessment using the Jadad scale [23].

Jadad Scale/Paper (Year)	Lai et al. (2018) [18]	Lu et al. (2019) [24]	Lin et al. (2021) [25]	Jueng et al. (2022) [26]
1. Was the study described as random? (yes = 1, no = 0)	1	1	1	0
2. Was the randomization scheme described and appropriate? (yes = 1, no = 0)	1	1	1	0
3. Was the study described as double-blind? (yes = 1, no = 0)	0	0	0	1
4. Was the method of double-blinding appropriate? (yes = 1, no = 0)	0	0	0	1
5. Was there a description of dropouts and withdrawals? (yes = 1, no = 0)	1	1	1	1
Total	3	3	3	3

. 1. Was the study described as random? 2. Was the randomization scheme described and appropriate? 3. Was the study described as double-blind? 4. Was the method of double-blinding appropriate? (Were both the patient and the assessor appropriately blinded?) 5. Was there a description of dropouts and withdrawals? Articles that met the criteria of involving older adult individuals from LTCFs who participated in horticultural activities or horticultural therapy and which utilized positive mental health assessment tools to demonstrate specific positive mental health effects were included. The articles were evaluated separately by two readers and then discussed, and a selection was made based on their evaluations. Four articles were selected using the Jadad scale, including one randomized controlled trial, two systematic reviews and meta-analyses, and one article with a quasi-experimental design.

3. Results

3.1. Selected Studies

This article selected four comprehensive studies, as shown in

Table 4. Study characteristics.

Author	Year	Region	Design	N	Age (SD) E/C	Population	Experimental Group	Control Group	Measures	Outcome
							Systematic Review and Meta-Analysis
Lai et al. [18]	2018	Hong Kong	Randomized Controlled trial	111	85.54(6.72)/ 83.74(7.66)	Older adults living in nursing homes	The HT protocol is a weekly 60 min program carried out over 8 weeks. The intervention protocol was tailor-made to fit the needs of the frail older individuals (e.g., an assistant helped cut the stems of plants for those with decreased muscle strength and dexterity). Each session consisted of various horticultural activities, such as fertilizing, repotting of plants, watering, trimming, propagation, species introduction, and seeding.	Social interaction effect of an intervention. All aspects of the Social Activity group were r equivalent to the HT group, except for the use of living plants. Activities that did not include the use of plants or plant-related materials were conducted. These activities included talking about the news, card games, and so on.	Happiness, depressive symptoms, self- efficacy, well-being, social networks, and engagement. The time points of measurement were at baseline (T0), immediately post intervention (T1), and 12 weeks post intervention.	HT was found to be effective in promoting subjective happiness for frail and prefrail nursing home residents. HT should be used to promote the psychosocial well-being of those who are frail.
Lu et al. [24]	2019	China	Systematic Review and M eta-Analysis	no	Over 65 years old	Older adults (dementia) living in nursing homes or LTCFs, etc.	Twenty-three articles were included for systematic review, whereas eight articles were included in the meta- analysis. Exterior space garden, walled garden. HT activities three times each week over a 10-week period. Activities lasted 30 to 45 min per session. Multisensory environments included a living room, garden, and Snoezelen room. HT activities lasted 30 min three times per week over 9 weeks in groups both indoors and outdoors and included three types of HT activities: cooking, crafts, and planting. HT activities were facilitated for half an hour per week over 9 weeks in addition to ordinary ADS activities, including open wander gardening with free and direct access from the dementia unit. Indoor garden activities (4 weeks) involved dropwort and bean sprouts. Participants: 9–48.		no	Patients with dementia benefit from horticultural therapy as it alleviates their degree of agitated behaviors, increases the length of time they engaging in activities, and decreases the length of time that they do nothing.
Lin et al. [25]	2021	China	Systematic Review and M eta-Analysis	884	Over 65 years old	Older adults living in nursing homes or LTCFs	Studies included in quantitative synthesis (meta-analysis: n = 4): unstructured HT (1 year); structured HT (4 weeks)		No routine care, waitlist control	HT can significantly improve upper body flexibility and aerobic endurance in older adults with cancer.
									Sensory stimulation and social interaction, social activities, interaction with a standard AD.	2. HT was found to be more effective in terms of promoting emotional functioning and well-being, subjective social functioning, and quality of life among the older adult.
Jueng et al. [26]	2022	Taiwan	Quasi-Experimental Design	86	82.22(7.47)/ 81.14(9.72)	Older adults living in long-term care facilities	Horticultural activity. A 40 min session was held once per week for 12 weeks.	Routine care	Positive mental health (Sense of Coherence Scale, SOC). A pretest was conducted one week before the intervention, and post-tests were administered at the 4th and 8th weeks of the research period, as well as one week after the intervention was complete (the 12th week).	Our findings indicate that horticultural therapy is effective in strengthening the SOC level of older LTCF residents without dementia.

. A total of 735 articles related to the topic were obtained through a database search (no documents were obtained through other channels), and a total of 698 articles remained after removing duplicate documents. The number of excluded articles was 661, and a total of 37 articles were selected after initial screening of the literature. The number of excluded articles was 33, and the reason for exclusion was that they did not involve older adults living in LTCFs. After a full-text review, a total of four articles met the inclusion criteria, specifically one randomized controlled trial, two systematic reviews and meta-analyses, and one article with a quasi-experimental design. The selected articles all had a low risk of bias according to the overall judgment criteria, indicating that these studies were eligible to provide highly reliable and valid data about the outcome.

3.2. Quality of the Eligible Studies

Of the four articles selected using the Jadad scale, one was a randomized controlled trial, and the remaining three included two articles that were systematic reviews and meta-analyses and one involving a quasi-experimental design, making a total of four articles. A systematic literature review was conducted on articles published between 2018 and 2022, and the main inclusion criteria were older adults aged 65 and above who resided in long-term care facilities and who had participated in horticultural activities or horticultural therapy.

3.3. Sample Size and Features

The sample size ranged from 86 to 884 participants. The age range of participants was 65 to 92 years old. The participants resided in various institutional care settings, such as LTCFs, nursing homes, dedicated elderly care facilities, and hospitals.

3.4. Activity Designs

The activity design involved an experimental group participating in horticultural therapy or horticultural activities and a control group participating in social activities or daily activities arranged by the institution. The activity design included both structured horticultural activities and unstructured horticultural activities. For unstructured horticultural activities, the frequency and duration of the activities varied across the studies.

One study had an 8-week intervention with a 60 min session each time. Another study had an intervention lasting for more than 10 weeks, with three sessions per week and each session lasting 35–40 min.

3.5. Measurements Tools

One study had an intervention lasting for more than 9 weeks, with three sessions per week and each session lasting 30 min. Finally, one study had an intervention with a frequency of once per week and each session lasting 40 min. The measurement tools used in the studies included the Happiness Scale, Depression Symptoms Scale, Self-Efficacy Scale, Well-Being Scale, Social Network Scale, Covenant Scale, Positive Psychological Health Scale, Sense of Coherence (SOC), and Quality of Life Scale.

3.6. Comprehensive Results

Based on the synthesis of the four selected articles, the results showed that participation in horticultural therapy among institutionalized older adults could increase their physical flexibility and aerobic endurance. Psychologically, participation in horticultural therapy increased subjective feelings of happiness, positive psychological well-being, and psychological and emotional comfort. Participation in horticultural activities among elderly residents with mild dementia in institutional settings can reduce aggression, provide a sense of purpose and social engagement, and improve overall quality of life.

4. Discussion

4.1. Health Benefits

The impact of older adults’ participation in gardening activities on health has been proven by evidence. In recent years, horticultural therapy has been applied to older adult residents in LTCFs, which has been shown to increase physical health in terms of flexibility, aerobic endurance, and other factors. This is similar to the physical health benefits that can be gained through gardening activities for older adult individuals in the community [18,24]. Despite the limited scope of this systematic literature review, it presents the concept of incorporating horticultural activities into the promotion of positive mental health among older adults in LTCFs to the caregiving team.

4.2. Promote Positive Mental Health

The use of horticultural therapy for older adult residents in nursing homes also involves exploring negative psychological states such as depression and anxiety [25,26,27]. Only Yao and Chen and Wang have explored the positive psychological health aspects of happiness and well-being [28,29]. An intervention study found that older adult residents in LTCFs who participated in a tabletop gardening activity for 40 min once a week showed similar positive psychological health status compared to the control group (which received regular activities arranged by the care facility) after four consecutive sessions. The positive effects continued to increase and reached a peak at the eighth week, which was sustained until the twelfth week [26,30]. Drageset, Espehaug, Hallberg, and Natvig’s study conducted in nursing homes in Bergen, western Norway, involved 52 cognitively healthy elderly individuals who were followed-up for five years to assess their level of life coherence, which is an aspect of positive psychological health. The results showed that the average score increased significantly, indicating a moderate to high level of positive psychological health improvement [31]. The results demonstrate that there is potential to promote positive psychological health among older adult residents in LTCFs. Therefore, it is recommended that gardening activities be incorporated into the regular activity design in such facilities.

4.3. Horticultural Activity Design and Cost-Effectiveness

A systematic literature review revealed that there has been limited exploration of the activity design of gardening activities for older adult residents in LTCFs. In consideration of the overall cost of LTCFs, it is important to design gardening activities that are both beneficial to the health of older adult residents and cost-effective. The content, frequency, interval time, and duration of each activity should all be carefully considered in order to achieve the desired health benefits while minimizing costs.

According to the literature, older adult residents in LTCFs benefited from participating in tabletop gardening activities once a week for 40 min when part of a total of 12 sessions held at one-week intervals. This has been shown to promote positive mental health among older adult residents [32]. A previous study recorded the direct and indirect costs of horticultural activities and applied cost-effectiveness analysis to discover the health cost-effectiveness for LTCFs [33].

4.4. The Cultural Context of Horticultural Activities in Asia

All four of the four systematic literature reviews empirically assessed the effects of horticultural activities in promoting positive mental health among older adults in the Asian region [34,35]. Moreover, these reviews also demonstrate the practical application of horticultural activities for individuals with moderate to severe dementia, resulting in increased focus [36] and enhanced satisfaction among older adults facing psychological issues [37]. These findings are consistent with Lin et al.’s systematic literature review on the impact of horticultural activity on the mental health of older adults in China. However, the underlying mechanisms and specific cause–effect relationships have been scarcely explored [38,39].

5. Conclusions

Organizing horticultural activities for older adults in LTCFs, through collaboration among healthcare professionals including nurses, social workers, and occupational therapists, is a beneficial approach. Further enhancement could come from integrating professionals from horticulture or landscape design fields. This would potentially amplify the benefits of older adult care and health promotion. The engagement of older adults from LTCFs in horticultural activities to improve positive mental health aligns with the World Health Organization’s concept of holistic health. Consequently, planning related horticultural activity designs while considering cost-effectiveness remains a persistently important subject. The chemical composition and diversity of volatile organic compounds (VOCs) in forests have been found to have various health-promoting effects on the human body, including benefits for respiratory health, brain function enhancement, fatigue reduction, and improvements in mood and cognition [40]. It is recommended to consider incorporating these findings when designing horticultural activities in LTCFs.

Horticultural therapy and horticultural activities have benefits in terms of enhancing the positive mental health of older adult residents in LTCFs. However, there are a limited number of experimental studies available on this topic.

6. Limitation

In studies related to the application of gardening activities in the elderly population, it is challenging to include experimental and control groups in the research design. This is indeed a limitation of this study. The reliability and validity of the findings from this systematic literature review are subject to limitations. Regarding internal validity, potential influences such as experimental measurement effects may be a concern. As for external validity, it depends on whether the research results can be generalized to broader populations, contexts, or timeframes.