Delphi Survey to Derive Operating Elements of Horticultural Therapy Programs for the Elderly People with Dementia

Sujeong Lee; Jonghyuck Kim; Sukyoung Yun

doi:10.11628/ksppe.2025.28.3.275

J. People Plants Environ > Volume 28(3); 2025 > Article

Lee, Kim, and Yun: Delphi Survey to Derive Operating Elements of Horticultural Therapy Programs for the Elderly People with Dementia

Research Paper

Horticultural Therapy & Wellbeing

Journal of People Plants Environment 2025;28(3):275-285.

Published online: June 30, 2025

DOI: https://doi.org/10.11628/ksppe.2025.28.3.275

Delphi Survey to Derive Operating Elements of Horticultural Therapy Programs for the Elderly People with Dementia

Sujeong Lee¹, Jonghyuck Kim², Sukyoung Yun³^*

¹Doctoral Student, Department of Horticulture, Graduate School, Daegu Catholic University, Gyeongsan 38430, Republic of Korea

²Professor, Major in Horticultural Therapy, Department of Life Care, Daegu Catholic University, Gyeongsan 38430, Republic of Korea

³Professor, Department of Horticulture, Graduate School, Daegu Catholic University, Gyeongsan 38430, Republic of Korea

^*Corresponding author: Sukyoung Yun, yune1004@cu.ac.kr, https://orcid.org/0000-0002-5862-0021

^{First author} Sujeong Lee, gesangliebe0@naver.com, https://orcid.org/0009-0006-6991-1509

Received February 5, 2025, Revised March 16, 2025, Accepted June 2, 2025,

This is a Peer-Reviewed Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

ABSTRACT

Background and objective: In order to provide a basis for creating a horticultural therapy program for the elderly with dementia, this study used the Delphi survey method, which extracts the opinions and judgments of experts to find consensus, to derive operating elements of a horticultural therapy program for the elderly with dementia.
Methods: The Delphi survey was conducted in three rounds between April 8 and April 29, 2024. The survey was conducted via email and social media. The expert Delphi panel consisted of 12 people, including professors of horticultural therapy-related departments, medical experts in the field of dementia and elderly, field workers in the field of dementia and elderly, and horticultural therapists.
Results: The questionnaire consisted of two parts: the first part was an open-ended questionnaire, consisting of 8 questions about the intervention goals, the total number of sessions, and the number of sessions per week as elements of implementing horticultural therapy programs for the elderly with dementia; the second part was a closed-ended questionnaire based on the results of the first part, consisting of 35 items and rated on a 5-point scale. The third round was a 23-item closed-ended questionnaire based on the results of the second round, with the importance of each item rated on a 5-point scale. The results of the first, second, and third Delphi surveys showed that the intervention goals of the horticultural therapy program for the elderly with dementia were cognitive (M = 4.67) and multidisciplinary (M = 4.08); frequency per week was once a week (M = 4.67) and once or twice a week (M = 4.25); total number of sessions was 12 (M = 4.25) and 15 (M = 4.58); time per session was 30–40 minutes (M = 4.42) and 40–50 minutes (M = 4.00) 2 items, number of participants: 3 (M = 4.00), 4 (M = 4.25), 5–6 (M = 4.00) 3 items, number of experts: 2 participants per expert (M = 4.33), 3 participants per expert (M = 4.08) 2 items; place of intervention: indoor training center (M = 4.00), indoor garden (M = 4.17), combined indoor and outdoor (M = 4.50) 3 items; target materials: all materials (M = 4.08), plants (M = 4.67) 2 items.
Conclusion: The results of the Delphi survey of horticultural therapy programs for older adults with dementia, including the intervention objectives, number of sessions per week, total number of sessions, time per session, and number of participants, can be used as a basis for designing horticultural therapy programs for older adults with dementia, and horticultural therapy programs that reflect these objectives can be specialized. This will contribute to the value and spread of horticultural therapy as a complementary and alternative therapy for the elderly with dementia.

Key words: activities, agreement analytical elements, horticultural papers, program rate

Introduction

Currently, Korea is experiencing an increase in the elderly population and aging at a rate that is difficult to find in the world. The global elderly population composition is expected to increase from 9.8% in 2022 to 20.1% in 2070, and the elderly population composition in Korea is expected to increase from 17.5% in 2022 to 46.4% in 2067 (Statistics Korea, 2022). Along with the rapid aging of the population, the number of dementia patients is also rapidly increasing every year. Among them, the estimated number of dementia patients in the elderly population aged 65 or older is about 840,000, and it is expected to increase to about 1.36 million in 2030, 2.17 million in 2040, and 3 million in 2050 (National Center for Dementia, 2018).

Dementia is a chronic and progressive brain disease that is difficult to recover from once it occurs, and the main symptom is cognitive dysfunction, including memory impairment that causes temporary forgetfulness of information acquired recently and an inability to remember new information due to damage to the brain nerves (Min et al., 2015). In addition, behavioral symptoms such as behavioral disorders, depression, sleep disorders, delusions, personality changes, and hallucinations also accompany the disease, and it causes difficulties in performing daily life activities, so the quality of life of not only the elderly but also the caregivers who support the elderly is deteriorating (Kim, 2004; Yang et al., 2012). Therefore, the lives of the elderly have a great impact on the nation and society, and are recognized as various problems of old age, and social support and intervention are more urgently needed (Shin, 2009).

The government promulgated the Dementia Management Act in 2011, established the Central Dementia Center in 2012, and announced the National Dementia Responsibility System Promotion Plan in September 2017 (Yang and Park, 2020). The national responsibility system was implemented on September 18, 2017, and has established specific implementation plans including the expansion of community dementia support centers, support for dementia screening and early detection, and provision and linkage of medical welfare, care, and nursing services. The academic world is also showing great interest in dementia, and is analyzing and supplementing from various perspectives for dementia prevention through policy discussions and research to suggest solutions (National Center for Dementia, 2018).

Among the various solutions for preventing dementia, interest in non-pharmacological treatments such as cognitive therapy, behavioral therapy, reminiscence therapy, art therapy, music therapy, occupational therapy, and horticultural therapy is increasing (Kim and Choi, 2010). Among them, horticultural therapy is also known to be effective for dementia patients as a non-drug treatment (Joo, 2017). At the heart of horticultural therapy is the restorative value of looking at plants and nature. Understanding the role of horticulture in working with special populations helps us to understand horticulture as a therapy for plant-human interaction (Relf and Dorn, 1995). Horticultural therapy helps to maintain and promote the health of the elderly, rehabilitate the elderly with chronic diseases or disabilities, and prevent geriatric diseases such as dementia (Haas, 1998), and because the program is conducted using plants in a greenhouse or garden, it creates a non-threatening and safe program environment for the elderly with dementia who have various functional declines. If you want to improve the function of the elderly with dementia suffering from cognitive decline through horticultural therapy, you can organize the program according to the degree of impaired cognitive function or adjust the difficulty level (Seo, 2000), and gardening activities activate the brain through physical elements such as color, shape, and texture of plants, chemical elements such as scent and taste, and also bring holistic therapeutic effects through exercise and social elements through human contact (Han, 2010). In particular, horticultural therapy has the advantage of utilizing living things and approaching from the perspective of fundamental human longing, allowing for an integrated approach such as cognitive stimulation and emotional stability (Kim, 2020). Therapeutic horticulture refers to the use of horticulture as a means to support the goals of a program and includes active or passive participation in some activity. In a study of older adults with dementia, emotional effects such as depression (36.8%), physical effects such as upper limb and hand function (25%), and cognitive effects such as functional ability, activities of daily living, or cognitive function (25%) were reported in the following order (Park et al., 2016). In a systematic literature review published in foreign countries, the effect of horticultural therapy on the elderly was reported to be significant, with improvements in cognitive effects, physical effects, and social relationships, but mixed results were found for functional effects (Nicholas et al., 2019). There are also limitations to comprehensive and objective verification of the effectiveness of horticultural therapies due to the variety of research methods, research tools, research subjects, research variables, and conflicting results.

Accordingly, this study was conducted to derive operational elements necessary for horticultural therapy programs for dementia patients through a Delphi survey targeting a group of experts in horticulture and dementia patients, and to provide data so that horticultural therapy programs for the treatment and rehabilitation of dementia patients can be professionally applied.

Research Methods

Delphi survey

In this study, a Delphi analysis was conducted with experts to identify operational elements of a horticultural therapy program for elderly people with dementia. The Delphi analysis method is used when seeking to obtain consensus from experts. It can improve the quality and reliability of information, and has the advantage of allowing free expression of opinions by guaranteeing anonymity, and allowing simultaneous participation of experts who are difficult to gather in one place (Sung, 2016). The Delphi survey is comprised of subjective opinions, which are the collective judgments of experts, but it is more reliable than individual opinions, and the premise is that the results derived through consensus are objective.

The Delphi survey was based on a meta-analysis of previous studies on horticultural therapy programs for older adults with dementia (Lee et al., 2024), and the endpoints were selected by the variables to be analyzed (purpose of the therapeutic intervention, participant group size, number of sessions per week, total number of sessions, and time per session), and then selected a panel of experts. The expert panel was selected from those who gave consent after receiving a sufficient explanation of the purpose of this study. After selecting the expert panel, the first questionnaire was created, and the survey was conducted in the first, second, and third rounds. The collected questionnaires were statistically processed and analyzed.

In a Delphi study, the expertise and number of members of the expert group are important. The expert group for this study was selected through purposeful sampling from among professors of horticulture and horticultural therapy, experts in dementia medicine, field experts at dementia care facilities, and welfare horticulturalists with extensive practical experience in implementing programs related to dementia care. In this study, a panel of 12 experts was recruited, the purpose of the study and analysis method were explained, and a questionnaire was administered.

The questionnaire was divided into three parts. The first part was open-ended and allowed the experts to freely describe their opinions on the purpose and implementation of the horticultural therapy program. The second questionnaire was closed-ended and described the results of the first questionnaire in sentences. It was designed to evaluate the appropriateness of each item on a 5-point scale and to allow for free description of additional opinions. The third survey presented the results of the second survey as an average and asked respondents to rate the appropriateness of each item on a 5-point scale.

The Delphi survey was conducted in three rounds from April 8 to 29, 2024. The survey was conducted using E-mail and SNS.

Data analysis

The questionnaires collected after the 1st, 2nd, and 3rd Delphi surveys were analyzed using the IBM SPSS v.29.0 program to calculate the mean, standard deviation, median, interquartile range, content validity ratio (CVR), agreement, convergence, and reliability for each round. Reliability was confirmed using Cronbach’s α coefficient.

Results and Discussion

Demographic characteristics

The expert group consisted of 4 professors of horticulture and horticultural therapy with research experience in the field of horticultural therapy, 2 experts in dementia geriatric medicine, 4 welfare horticulturalists with experience in operating programs related to dementia geriatric patients, and 2 field experts from dementia geriatric facilities. It was determined that expertise in the relevant field was secured with 9 people holding a doctorate (75.0%), 1 person holding a master's degree (8.3%), 1 person holding a bachelor's degree (8.3%), and 1 people holding other degrees (8.3%). In terms of experience in each field, 2 people ( 16.7%) had 5–10 years, 6 people (50.0%) had 10–15 years, 4 people (33.3%) had 20–30 years. 83.3% of the respondents had more than 10 years of experience, showing that they had extensive experience in the fields of dementia care and horticultural therapy. Age range was 3 people (25.0%) in their 40s, 6 people (50.0%) in their 50s, 3 people (25.0%) in their 60s, and 1 person (7.7%) from other age groups (Table 1).

1st Delphi analysis

The questionnaire for the first Delphi survey was in the form of an open-ended questionnaire, allowing the panel of experts to express their opinions more freely. The questionnaire items consisted of questions about operational elements necessary for implementing a horticultural therapy program for dementia elderly people, including the purpose of horticultural therapy intervention, number of sessions per week, total number of sessions, time per session, number of participants, number of participating experts, intervention location, and target materials (Table 2).

The first Delphi survey was conducted from April 8 to 13, 2024, and the expert panel presented various opinions as a result of the first Delphi survey. The content presented in sentences was structured by three people, one professor of horticulture, one doctoral student, and one professor of horticultural therapy, extracting keywords from the sentences and comparing them (Table 3). As a result, we consolidated similar opinions among the 86 comments to arrive at a total of 35 items.

The intervention objectives of the horticultural therapy program for the elderly with dementia were derived from four domains: cognitive, complex, physical, and emotional. The holistic domain was suggested because it can help improve cognitive function, emotional changes, sociality, and physical activity. The physical domain was suggested because it trains small muscles through activities involving touching and using plants. It was suggested that the emotional domain should be the intervention objective because stress relief and psychological healing are necessary after dementia diagnosis.

The number of times per week was derived from 5 items in total: once a week, twice a week, three times a week, 1~2 times a week, and 7 times a week. It was suggested that once a week is appropriate considering that changes are observed after about a week of planting and the life cycle of cut flower materials. In addition, since it is good for cognition to repeat once more before a week is over, twice a week was suggested, and since it is good to perform horticultural therapy every day, it was also suggested that 7 times a week is good.

A total of three items were derived, such as the total number of sessions being 12 sessions, 15 sessions, and that they should be conducted every day without having to set a total number of sessions. Opinions were presented that they should be conducted in units such as one season, one quarter, etc., that it is good for elderly people with dementia to feel the change of seasons, and that continuous intervention should be conducted, not temporary intervention.

The mediation time was derived from four items: 20~30 minutes, 30~40 minutes, 40~50 minutes, and 60 minutes. Some suggested that it should be conducted for 20~30 minutes because it is difficult to sit and do activities for long periods of time, while others suggested that it should be conducted for 60 minutes because of chronic diseases other than dementia and decreased muscle strength and concentration.

The number of participants in the program was 1, 3, 4, 5~6, 10, and 30, resulting in a total of 6 items. Opinions were presented that one-on-one care should be provided, that it is more appropriate to do it together than alone, and that it should be conducted with 4 people because they can help each other in pairs, and that it should be conducted with 30 people because most dementia facilities such as care centers have 20~30 or more people.

The number of experts participating in the program was derived from four items in total: 1 expert per 1 participant, 1 expert per 2 participants, 1 expert per 3 participants, and 1 expert per 5 participants. Some suggested that 1 expert per 1 participant is appropriate because it is the most stable and effective, while others suggested 1 expert per 5 participants is appropriate because people get distracted when there are too many people around.

The program intervention place was derived from five items: all possible places, indoor training rooms, outdoor gardens, indoor gardens, and indoor and outdoor settings in parallel. It was suggested that an indoor training room is appropriate because it can deal with stability issues and unexpected behaviors, that an outdoor garden is appropriate because it allows for a sense of the seasons and environmental changes, and that indoors can improve fine motor skills through delicate movements, while outdoors can be effective for large movements and balance, so if safety facilities are in place, it is recommended to use indoors and indoors in parallel.

The program materials were derived from four items: all materials, fruits, herbs, and flowers. Opinions were given that all materials are possible if the subject prefers them, that herbs are appropriate because they provide emotional stability when smelled and can be used as food, and that flowers are appropriate because they allow the sense of the four seasons and are safe.

Through the first expert Delphi survey, a total of 35 items were derived, including 4 items on the goals of horticultural therapy intervention, 5 items on the number of sessions per week, 3 items on the total number of sessions, 4 items on the time per session, 6 items on the number of participants, 4 items on the number of participating experts, 5 items on the intervention place, and 4 items on materials.

2nd Delphi analysis

The second Delphi questionnaire presented 35 items derived from the opinions of experts in the first Delphi survey in the form of sentences and utilized a Likert scale (5 points). The ratings were set in order of preference from very inappropriate (1 point) to very appropriate (5 points). The results of the second Delphi analysis showed that the reliability of the elements of the horticultural therapy program for elderly people with dementia was at a reliable level, with Cronbach’s α = 0.791.

The content validity ratio (CVR) value has a minimum value determined by the number of participating experts(Sung 2016). Since the number of experts who completed the second questionnaire was 12, the minimum CVR value of 0.56 or higher was applied (Sung, 2016). If the output mean is 4.0 or higher, the standard deviation is 1.00 or lower, the expert consensus is .75 or higher, and the convergence is .50 or lower, the expert panel's opinions can be considered to have reached an agreement(Sung, 2016).

For the goals of mediation, the minimum values of the output mean, standard deviation, agreement, convergence, and content validity were confirmed, and as a result, items in the cognitive, complex, and emotional domains were derived through expert consensus, and the cognitive domain (CVR=0.83) was derived with the highest validity rate.

In terms of frequency per week, items such as once a week, twice a week, and 1–2 times a week were derived through expert consensus, and twice a week (CVR = 0.83) showed the highest validity rate.

For the entire session, 12 and 15 items were derived through expert consensus. The mediation time was derived from the experts' consensus of 30~40 minutes and 40~50 minutes, and 30 ~40 minutes (CVR = 0.83) was derived as the highest validity rate.

The number of participants was derived by expert consensus on items of 1, 3, 4, and 5~6 people. The number of experts participating in the program was derived by expert consensus on items of 1 expert per 1 participantt, 1 expert per 2 participants, and 1 expert per 3 participants, and 1 expert per 1 participant (CVR = 0.83) was derived with the highest validity rate.

The placess were selected through expert consensus as indoor training rooms, indoor gardens, and indoor-outdoor combinations, and indoor-outdoor combinations (CVR = 0.83) were selected as having the highest validity rate. Materials were derived from all materials, herbs, and flower items through expert consensus, and flower (CVR = 1.00) was derived through expert consensus. 35 items derived from the first Delphi survey were presented, and expert consensus was reached on 23 items (Table 4).

3rd Delphi analysis

The third Delphi questionnaire presented 23 items derived from the experts who participated in the second Delphi survey in sentence form. The results of the second analysis presented the average and the range where 50% of the respondents gathered, and asked them to rate the importance. It was constructed on a 5-point Likert scale, with choices ranging from very inappropriate (1 point) to very appropriate (5 points). The results of the third Delphi analysis showed that the reliability of the elements of the horticultural therapy program for elderly people with dementia was at a reliable level, with Cronbach’s α = .683.

Since the number of participating panelists was 12, the minimum CVR value of .56 for 12 people suggested by Lawshe was applied. In the study by Sung (2016), the opinions of expert panels were judged to be in agreement when the output mean was 4.0 or higher, the standard deviation was 1.00 or lower, the experts' agreement was 0.75 or higher, and the convergence was 0.50 or lower. Based on this, this study judged that expert opinions were agreed upon if the following conditions were met: the calculated mean was 4.0 or higher, the standard deviation was 1.00 or lower, the expert agreement was .75 or higher, the convergence was 0.50 or lower, and the CVR minimum was 0.56 or higher.

As a result of the third Delphi survey, the average and 50% range of 23 items derived from the second Delphi survey were presented, and as a result of experts rating the importance on a 5-point scale, consensus was reached on 18 items. Looking at the items derived through consensus, two items were derived from the intervention purpose of the horticultural therapy program for elderly people with dementia: cognitive domain (M=4.67) and complex domain (M=4.08), and two items were derived from the number of times per week: once a week (M=4.67) and 1~2 times a week (M=4.25). This is similar to the research results (Rim, 2013) that found that implementing an art therapy program once a week is appropriate for the elderly. In the total number of sessions, 2 items were derived: 12 sessions (M=4.25) and 15 sessions (M=4.58). This is similar to the results of Park (2023), who found that the larger the number of sessions, the larger the effect size in a horticultural therapy program for older adults with dementia, and Hong (2006) and Kim (2007), who found higher effect sizes for 21 to 25 sessions and 26 to 30 sessions, and Jang (2010), who found larger effect sizes for 21 to 30 sessions and 31 or more sessions. It is also similar to the results of Jung (2024), who found that more than 12 sessions had a larger effect size than less than 12 sessions in art therapy for older adults with dementia. In terms of time per session, two items were derived: 30~40 minutes (M=4.42) and 40~50 minutes (M=4.00). This is similar to the results of Hong's (2019) Delphi study on a customized exercise program for elderly people with dementia, which found that 30 minutes was appropriate for elderly people with dementia. For the number of program participants, three items were derived: 3 people (M=4.00), 4 people (M=4.25), and 5~6 people (M=4.00), and for the number of program operation experts, two items were derived: 2 participants per expert (M=4.33) and 3 participants per expert (M=4.08). This is different from Park's (2023) meta-analysis of horticultural therapy for older adults with dementia, which found that programs with 41 or more participants had the largest effect sizes. However, there are only four papers with less than 10 participants in the existing data, so it seems necessary to conduct experimental studies with 3 people, 4 people, 5~6 people participants, depending on the opinions of experts. In the intervention site of the horticultural therapy program for the elderly with dementia, three items were derived: indoor training room (M=4.00), indoor garden (M=4.17), and indoor and outdoor combination (M=4.50). In the program target materials, two items were derived: all materials (M=4.08) and flowers (M=4.67, Table 5).

Conclusion

This study was conducted to derive objective operational elements of a horticultural therapy program for elderly people with dementia by using a Delphi survey that extracts opinions and judgments from a group of experts to find a point of agreement, thereby providing basic data for planning a horticultural therapy program for elderly people with dementia. The expert Delphi panel selected 12 people. The experts who participated in the survey were 4 professors of horticulture and horticultural therapy with research experience in the field of horticultural therapy, 2 experts in dementia geriatric medicine, 4 welfare horticulturalists with experience in operating programs related to dementia geriatric patients, and 2 field experts from dementia geriatric facilities.

The composition of the questionnaire was as follows: The first was an open-ended questionnaire, consisting of 8 questions on the implementation elements of the horticultural therapy program for dementia patients, including the purpose of intervention, total number of sessions, and number of times per week. The second was a closed-ended questionnaire based on the results of the first questionnaire, consisting of 35 items, which were rated on a 5-point Likert scale. The third was a 23-item questionnaire, which was composed by analyzing the results of the second questionnaire, and the importance was rated on a 5-point Likert scale.

As a result of the Delphi surveys conducted in the 1st, 2nd, and 3rd rounds, two items were derived from the intervention objectives of the horticultural therapy program for elderly people with dementia: cognitive domain (M = 4.67) and complex domain (M = 4.08). In the number of times per week, there were 2 items: once a week (M = 4.67) and 1~2 times a week (M = 4.25), in the total number of sessions, there were 2 items: 12 sessions (M = 4.25) and 15 sessions (M = 4.58), in the time per session, there were 2 items: 30~40 minutes (M = 4.42) and 40~50 minutes (M = 4.00), in the number of participants, there were 3 items: 3 people (M = 4.00), 4 people (M = 4.25), and 5–6 people (M = 4.00), in the number of experts, there were 2 items: 2 participants per expert (M = 4.33) and 3 participants per expert (M = 4.08), in the location of the intervention, there were 3 items: indoor training center (M=4.00), indoor garden (M = 4.17), and indoor and outdoor combination (M = 4.50), and in the target materials, there were all. Two items were derived: materials (M = 4.08) and flowers (M = 4.67).

The significance of the above results lies in the fact that they objectively derived operational elements for the implementation of horticultural therapy programs for dementia elderly people by gathering opinions from a group of experts. It is expected that they can be used as operational elements for planning and implementing horticultural therapy programs for dementia elderly people in the future.

However, among the operational factors of the horticultural therapy program for the elderly with dementia that resulted from this study, the number of participants was found to be the largest effect size in the meta-analysis study by Lee et al. (2024), but the expert Delphi analysis showed that it was recommended to operate the program with 3 to 6 participants. It is necessary to conduct a comparative study by implementing a horticultural therapy program for the elderly with dementia in the future. In addition, it is necessary to objectify the results of this study by planning and implementing a horticultural therapy program for the elderly with dementia and comparing and analyzing the results.

Notes

This work was supported by research grants from Daegu Catholic University in 2024.

Table 1

Demographic characteristics of survey respondents (n=12)

Item	Type	N (%)	Number (%)
Occupation	Professor of horticulture(Horticultural therapy)	4 (33.3)	12(100%)
	Dementia geriatric medical specialist	2 (16.7)
	Horticultural therapist	4 (33.3)
	Field experts in elderly with dementia	2 (16.7)

Education level	Doctoral degree	9 (75.0)	12(100%)
	Master degree	1 (8.3)
	Bachelor’s degree	1 (8.3)
	Etc.	1 (8.3)

Career	5~10 years	2 (16.7)	12(100%)
	10~15 years	6 (50.0)
	15~20 years	0 (0)
	20~30 years	4 (33.3)
	over 30 years	0 (0)

Age	20’s	0 (0)	12(100%)
	30’s	0 (0)
	40’s	3 (25.0)
	50’s	6 (50.0)
	Over 60’s	3 (25.0)

Table 2

Configure the 1st Delphi

Content	Question format
Goal of horticultural therapy for elderly with dementia	Narrative
Number of horticultural therapy per week for elderly with dementia	Narrative
Total session of horticultural therapy for elderly with dementia	Narrative
Mediation time per session of horticultural therapy for elderly with dementia	Narrative
Number of participants in horticultural therapy for elderly with dementia	Narrative
Number of horticultural therapy experts for elderly with dementia	Narrative
A place for horticultural therapy for seniors with dementia	Narrative
Materials subject to horticultural therapy for seniors with dementia	Narrative

Table 3

Results of the 1st Delphi survey of horticultural therapy programs for elderly with dementia

Content	Presentation of opinion	Category	No. of item
Goal	Dementia is a cognitive disorder that impairs brain function.	Cognitive areas	1	(4)
	Horticultural therapy can help in many areas, including cognitive and emotional changes, social and physical activity.	Complex areas	1
	Horticultural therapy programs are muscle training.	Physical areas	1
	Stress relief and psychological healing are necessary after a dementia diagnosis.	Emotional areas	1

Sessions per week	When you plant the plants, you shouldn’t see any changes until a week or so later. Life cycle of cut flower materials, etc.	1 time per week	1	(5)
	Repeating it one more time before the week is up is good for cognition.	2 times per week	1
	Repeat the activity every other day or so to help you remember it.	3 times per week	1
	Adjustable based on the condition and status of the recipient.	1~2 times per week	1
	Daily exercise is good for seniors with dementia.	7 times per week	1

Full session	Split by quarter, etc.	12 sessions	1	(3)
	Feeling the change of seasons is good for seniors with dementia.	15 sessions	1
	This should be an ongoing process, not a one-time intervention.	Every day, no need to commit to a full session	1

Time	Seniors with dementia have difficulty sitting for long periods of time.	20~30 min.	1	(4)
	Attention span considerations, therapist attention span, etc.	30~40 min.	1
	Poor focus, including consideration of prep, deployment, and wrap-up time, etc	40~50 min.	1
	Consider chronic conditions other than dementia, such as decreased strength, concentration, etc.	60 min.	1

Number of participants	Seniors with dementia need one-on-one care.	1 person	1	(6)
	This is the number of people who can be taught without an assistant instructor.	3 person	1
	It’s better to work together than alone, an even number of people can help each other in pairs, etc.	4 person	1
	Communicate without irritating microphones, interact with instructors, etc.	5~6 person	1
	Programs are harder to run if there are fewer than 5 participants, smaller group of people to communicate with, etc.	10 person	1
	In most cases, the number of residents in a center such as a shelter is 20–30 or more.	30 person	1

Number of experts	The safest and most effective	1 expert per participant	1	(4)
	Needs close care from a specialist, can be cared for bilaterally by one caregiver, etc.	1 expert per 2 participants	1
	One instructor can assist up to three, etc.	1 expert per 3 participants	1
	Seniors with dementia are more distracted by the number of people around them.	1 expert per 5 participants	1

Place	Anywhere is possible, etc.	All place	1	(5)
	Safety concerns, ability to deal with unexpected behavior, etc.	Indoor training room	1
	Can feel the seasons, etc.	Outdoor garden	1
	If outdoors, there are safety concerns, etc.	Indoor garden	1
	It can be used indoors to improve fine motor skills, outdoors to improve gross motor balance, etc.	Indoors and outdoors	1

Materials	Any ingredients are acceptable if preferred by the person with dementia.	Any material	1	(4)
	Likes things that can be eaten.	Fruits	1
	Scent is emotionally calming, can be used as food, etc.	herbs	1
	Plants can help people with dementia feel the seasons.	flowers	1

Table 4

Results of the 2nd Delphi survey of horticultural therapy programs for elderly with dementia

Item	Category	M	SD	Med	QD		A^z	B^y	CVR^x	Pass

					25%	75%
Goal	Cognitive domains	4.50	0.67	5	4	5	0.80	0.5	0.83	○
	Complex domains	4.25	0.97	5	4	5	0.80	0.5	0.67	○
	Physical domains	3.33	0.89	3	3	4	0.67	0.5	−0.17
	Emotional domains	4.08	0.90	5	4	5	0.80	0.5	0.67	○

Session per week	1 time per week	4.50	0.67	4	3	5	0.50	1	0.83	○
	2 times per week	4.08	0.79	4	3	4	0.75	0.5	0.83	○
	3 times per week	2.75	1.29	3	1.5	4	0.17	1.25	−0.50
	1~2 times per week	3.92	0.99	4	3	4	0.75	0.5	0.67	○
	7 times per week	2.33	1.23	2	1	3	0.00	1	−0.83

Total sessions	12 sessions	4.00	0.95	4	4	5	0.75	0.5	0.67	○
	15 sessions	4.08	0.90	4	4	5	0.75	0.5	0.67	○
	Every day, no need to commit to a full session	3.08	1.16	3	2	3.5	0.50	0.75	−0.50

Mediation time	20~30 min.	3.25	1.22	3	2.5	4.5	0.33	1	−0.17
	30~40 min.	4.42	0.67	4	4	5	0.75	0.5	0.83	○
	40~50 min.	4.17	0.83	4	4	5	0.75	0.5	0.83	○
	60 min.	3.08	1.51	3	2	4.5	0.17	1.25	−0.17

Number of participants	1 persons	4.17	0.83	4	4	5	0.75	0.5	0.83	○
	3 persons	4.00	0.60	4	4	5	0.75	0.5	0.67	○
	4 persons	4.08	0.90	4	4	5	0.75	0.5	0.67	○
	5~6 persons	4.08	0.90	4	4	5	0.75	0.5	0.67	○
	10 person	2.42	1.38	2	1	3.5	−0.25	1.25	−0.50
	30 person	1.67	1.23	1	1	2	0.00	0.5	−0.83

Number of experts	1 expert per 1 participant	4.17	0.83	4	4	5	0.75	0.5	0.83	○
	1 expert per 2 participants	4.33	0.98	5	4	5	0.80	0.5	0.67	○
	1 expert per 3 participants	4.08	0.90	4	3	4	0.75	0.5	0.67	○
	1 expert per 5 participants	2.33	1.30	2	1	3	0.00	1	−0.67

Place	All place	3.08	1.00	3	2	4	0.33	1	−0.33
	Indoor training room	4.08	0.90	4	3	4	0.75	0.5	0.67	○
	Outdoor garden	3.17	1.11	3	2	4.5	0.17	1.25	−0.33
	Indoor garden	4.00	0.85	4	4	5	0.75	0.5	0.67	○
	Indoors and outdoors	4.33	0.89	5	4	5	0.80	0.5	0.83	○

Materials	All materials	4.08	0.89	4	4	5	0.75	0.5	0.67	○
	Fruits	2.83	1.19	3	2	4	0.33	1	−0.17
	Herbs	4.33	0.65	4	4	5	0.75	0.5	0.67	○
	Flowers	4.50	0.52	5	4	5	0.80	0.5	1.00	○

^z The closer to 1, the more valid.

^y The closer to 0, the more valid.

^x Valid when the value is 0.56 and over

Table 5

Results of the 3rd Delphi survey of horticultural therapy programs for elderly with dementia

Item	Category	M	SD	Med	QD		A^z	B^y	CVR^x	Pass

					25%	75%
Goal	Cognitive domains	4.67	0.65	5	4.25	5	0.85	0.38	0.83	○
	Complex domains	4.08	0.90	4	4	5	0.75	0.50	0.67	○
	Emotional domains	4.00	0.95	4	3.25	5	0.56	0.88	0.50

Session per week	1 time per week	4.67	0.65	5	4.25	5	0.85	0.38	0.83	○
	2 times per week	3.75	0.75	4	3.25	4	0.81	0.38	0.50
	1~2 times per week	4.25	0.62	4	4	5	0.75	0.50	0.83	○

Total sessions	12 sessions	4.25	0.87	4	4	5	0.75	0.50	0.83	○
Total sessions	15 sessions	4.58	0.67	5	4	5	0.80	0.50	0.83	○

Mediation time	30~40 min.	4.42	0.67	4.5	4	5	0.78	0.50	0.83	○
Mediation time	40~50 min.	4.00	0.85	4	4	5	0.81	0.38	0.67	○

Number of participants	1 persons	3.42	1.38	3.5	3	4.75	0.5	0.88	0
	3 persons	4.00	0.60	4	4	4	1	0	0.67	○
	4 persons	4.25	0.97	4.5	4	5	0.78	0.5	0.67	○
	5~6 persons	4.00	0.85	4	4	4.75	0.81	0.38	0.67	○

Number of experts	1 expert per 1 participant	3.83	0.94	4	3	4.75	0.56	0.88	0.33
	1 expert per 2 participants	4.33	0.65	4	4	5	0.75	0.5	0.83	○
	1 expert per 3 participants	4.08	0.96	4	4	5	0.75	0.5	0.67	○

Place	Indoor training room	4.00	0.85	4	4	4.75	0.81	0.38	0.67	○
	Indoor garden	4.17	0.58	4	4	4.75	0.81	0.38	0.83	○
	Indoors and outdoors	4.50	0.90	5	4	5	0.80	0.5	0.83	○

Materials	All materials	4.08	0.79	4	4	4.75	0.81	0.38	0.83	○
	Herbs	3.92	0.51	4	4	4	1.00	0	0.67
	Flowers	4.67	0.49	5	4	5	0.80	0.5	1.00	○

^z The closer to 1, the more valid.

^y The closer to 0, the more valid.

^x Valid when the value is 0.56 and over

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