Oral Exercise With Lay Health Advisor Strategy on Oral Self-care Behaviors, Oral Hygiene, Oral Function and Quality of Life Among Older Adults in Aboriginal Communities in Taiwan: A Randomized Controlled Trial
Phase: NA
Conditions: Oral Health
Sponsor: Kaohsiung Medical University Chung-Ho Memorial Hospital

 
 
 
Oral Exercise with Lay Health Advisor Strategy on Oral Self-care 
Behaviors, Oral Hygiene, Oral Function and Quality of Life among 
Older Adults in Aboriginal Communities in Taiwan: A Randomized 
Controlled Trial 
 
 
 
 
 
 
 
 
 
 
Protocol ID: KMUHIRB-SV(I)-20190010    
Secondary IDs: NHRI-108A1-PHCO-03191908 
 
Document date : 2021.09.08 
Approval dated of clinical trial by human subjects protection review 
board : 2019.04.12 
 
 

BACKGROUND 
According to United Nations statistics, the global population has reached 7.7 
billion in 2019, and the population over 65 has reached 700 million, accounting for 
9.3% of the world's total population [1]. Taiwan turned into an elderly society in 2018, 
with 3.31 million people over 65 years old, accounting for 14.1% of the country's total 
population. It is estimated that it will enter a super-aged society in 2025 [2]. Oral 
function will gradually degenerate with age; dental diseases, decreased chewing and 
swallowing functions, and decreased salivary gland function can also affect food intake, 
cause malnutrition and other problems, and the higher risk of chronic diseases. Elderly 
people with swallowing dysfunction and poor oral health are 2.6 times more likely to 
die than those with better oral health [3]. The number of teeth is a crucial factor affecting 
masticatory function. Several studies have also indicated that older people with fewer 
posterior teeth and fewer teeth overall are more likely to experience difficulty chewing 
[4, 5]. Dysphagia and masticatory performance may serve as pathways through which 
xerostomia affects quality of life [6]. A community-based educational program 
targeting oral function improvements in older people may be a promising strategy for 
improving OHRQoL.  
Previous studies have highlighted a health disparity between aboriginal and 
general population[7-9]. The uneven distribution of access to medical resources and 
insufficient health professional manpower in remote aboriginal villages has led to such 
health disparities. The aborigines have poor oral hygiene habits and lower level of oral 
health-related knowledge than those in urban areas [10]. The aborigines living in remote 
areas have unique cultures, languages, and values. Betel nut is an indispensable item in 
the traditional society of Taiwan's aborigines. Betel nut chewers usually suffer from 
severe oral lesions and alveolar bone loss [11,12]. In addition, aboriginal people’s 
dependence on alcohol and smoking rates are also higher than those of ordinary people. 

Therefore, the incidence of oral diseases (such as dental caries, periodontal disease, 
missing teeth, etc.) is higher than that of the general population [13-15]. Lay Health 
Advisors (LHAs) are chosen from the community; they share similar values, ethnic 
background, and socioeconomic status, and speak the same language as the people they 
serve. They are also known as natural helpers and are recommended to provide 
emotional and social services to local health institutions and communities [16-18]. Its 
advantages are to save manpower, money and reduce language and cultural barriers. 
LHA intervention strategies have been widely used in the community-based program, 
such as cancer screening, smoking cessation, risk behaviors, and the delivery of health 
information [19-23]. A recent study using an LHA strategy in aboriginal communities 
in Taiwan has proved more effective than reading leaflets alone for reducing barriers 
toward oral cancer screening and increasing self-efficacy for oral cancer self-
examination [24]. Another study [25] conducting a community-level LHA program that 
addressed oral health disparities in the access and utilization of dental caries preventive 
services for immigrant children in Taiwan. A 4-week LHA intervention with one-on-
one lessons and experience-sharing proved more effective in improving immigrant 
children’s decay teeth, immigrant mothers’ dental caries–related knowledge and 
maternal preventive behaviors than reading only the brochure. 
Employing LHAs strategy can be effective in improving access to care and 
delivery of health care services for groups that have traditionally lacked access to 
adequate health care. Oral exercise (i.e., neck exercises, salivary gland massages, and 
vocal exercises) can effectively improve the oral diadochokinesis (DDK) rate and 
reduces xerostomia, dysphagia, and poor masticatory performance [9]. Early oral 
function intervention may be a valuable and actionable target for older adults to 
maintain quality of life. This is the first study to use the Lay Health Advisor (LHA) 
strategy to improve the oral function of the older adults in aboriginal communities. In 

the present study, we aimed to evaluate the effectiveness of community-based oral 
exercise with LHA intervention on the oral health-related quality of life, oral function 
and oral self-care behaviors. 
METHODS 
2.1 Design 
A randomized controlled trial (RCT) was conducted. The participants recruited 
from aboriginal communities in Eastern Taiwan. Data collecting time was from 2019 
to 2020. Participants from the identified communities were randomly assigned to EG 
or CG using random table. 
2.2 Participants 
Participants who were 55 years old or above and indigenous people were recruited 
in the present study. Participants who were disability, have had oral cancer, impaired 
facial appearance and impaired cognitive function were excluded. Impaired cognitive 
function was screening by Short Portable Mental Status Questionnaire (SPMSQ). 
Participants were recruited according to the predetermined minimal sample size 
estimated based on a type I error = 0.05, power = 0.95, and effect size (ES) f = 0.25 
(medium effect in Cohen’s f) [26]. The number of samples in each group was expected 
66 participants. An additional 30% drop out rate was added. The final number of 
samples for each group were required at least 86 participants. The total sample size was 
122 and 118 in EG and CG, respectively. 
2.3 Instrument 
A structured questionnaire was developed to collect data on demographics (i.e., 
age, sex, education level), oral function (i.e. swallowing, oral DDK, masticatory 
performance, saliva flow rate and perceived dysphagia), oral hygiene (i.e. plaque 
control record, plaque index and Winkel tongue coating index), oral self-care behaviors 

(i.e. dental visit, tooth-brushing, and interdental brush) and OHRQoL. Items were 
reviewed by a panel of experts to assess content validity. The content validity index was 
0.89–1.00. To ensure that the study participants understood the content, the 
questionnaires were pilot tested on 10 indigenous old adults. The reliability of each 
scale was assessed in terms of internal consistency. Swallowing was assessed with 
repetitive saliva swallowing test (RSST), masticatory performance was assessed using 
color-changeable chewing gum (Xylitol, 3.0 g; Lotte, Saitama, Japan) and /pa/, /ta/, and 
/ka/ syllables was assessed with oral diadochokinesis (DDK) test using KENKOU-
KUN (Produced by TAKEI, japan dental supply). 
2.4 Outcomes  
2.4.1 Oral health-related quality of life 
OHRQoL was measured using the Geriatric Oral Health Assessment Index 
(GOHAI) , which was translated into Chinese for the participants (GOHAI-T) [27]. For 
example, “Are you satisfied or happy with the appearance of your teeth, gums or 
dentures?” Possible responses were range from 1 (always) to 5 (never). The total score 
ranged from 12 to 60 points. The higher the score, the better the quality of life. 
Cronbach’s alpha was 0.75 for the scale. 
2.4.2 Oral function index 
The Repetitive Saliva-Swallowing Test (RSST) was used to evaluate swallowing. 
Participants were asked to swallow saliva as many times as possible in 30 seconds [28]. 
For oral DDK, the participants were asked to repeat the /pa/, /ta/, and /ka/ syllables as 
quickly as possible, and the number of articulations was counted [29]. Using a digital 
counter, we separately counted the number of articulations of the /pa/, /ta/, and /ka/ 
syllables within 10 seconds. Masticatory performance was evaluated using the color-
changeable chewing gum (Xylitol, 3.0 g Lotte, Saitama, Japan). This chewing gum 
contains xylitol, citric acid, and red, yellow, and blue dyes that change color when 

subjected to masticatory forces from chewing. The red dye is pH sensitive and changes 
color under neutral or alkaline conditions. Citric acid maintains a low internal pH of 
the yellowish-green gum before chewing commences. The gum changes to red when 
chewed because the yellow and blue dyes seep into saliva, and citric acid elution 
produces the red color [30]. Participants were asked to chew for 2 minutes. Two minutes 
later, the observer checked the color of the gum by using a color chart of five color 
gradations ranging from 1 (very poor) to 5 (very good). Saliva flow rate was measured 
the saliva flow rate in one minute (ml/min). Participants were asked to chew the gauze 
for two minutes and spited out the gauze and saliva back into the test tube. After 
centrifuging the saliva of the gauze, pour the saliva into a measuring tube to measure 
the volume of the saliva. Perceived dysphagia, which was defined as a subjective 
perception of problems swallowing, was measured using the swallowing screening 
scale developed by Ohkuma [31] and has an internal consistency Cronbachα’s alpha 
coefficient of 0.85. Examples of questions included “Do you ever have difficulty 
swallowing?” “Do you ever have difficulty as a result of cough up phlegm during or 
after a meal?” “Does it take you longer to eat a meal than it used to?” “Do you feel that 
it is becoming difficult to eat solid foods?” and “Do you ever have difficulty sleeping 
because of coughing during the night?” Possible responses were “obviously” 
(frequently), “slightly” (sometimes), or “no” (never). Respondents with at least one 
severe symptom were classified as having dysphagia. 
2.4.3 Oral hygiene index 
Plaque control record (PCR) was measured the percentage of tooth surface with 
plaque. PCR range from 0 to 100% [32]. Plaque index (PI) was measured the six 
indicator teeth 12, 16, 24, 32, 36, 44 and the score for each tooth is range from 0 to 3 
(0 = no plaque, 1 = a film of plaque adhering to the free gingival margin and adjacent 
area of the tooth, 2 = moderate accumulation of soft deposit s within the gingival pocket, 

or the tooth and gingival margin which can be seen with the naked eye, 3 = abundance 
of soft matter within the gingival pocket and/or on the tooth and gingival margin). Then 
summing the average of 6 indicators teeth. Winkel tongue coating index (WTCI) [33] 
was measured the accumulation of coating on the surface of the tongue. The tongue was 
divided into six areas (three posterior and three anterior), and the coating was scored as 
0 = no coating, 1 = light coating, or 2 = severe coating; scores ranged from 0 to 12 
points. 
2.4.4 Oral self-care behaviors 
The question of dental visit, “Do you see a dentist every six months?” Possible 
responses were “Yes”, “No”. The question of tooth-brushing, “How many times do you 
brush your teeth a day?” Possible responses were “None”, “One time”, “Two times” 
and “More than 3 times”. The question of interdental brush, “Do you use an interdental 
brush every day?” Possible responses were “Yes”, “No” and “Never heard”. The 
question of flossing, “Do you use dental floss every day?” Possible responses were 
“Yes”, “No” and “Never heard”. 
2.4.5 Covariates 
This study examined age, gender and educational level as covariates. 
2.5 LHA recruitment and training 
A total of 30 people was recruited for LHA training. LHAs are recommended by 
public health center and tribal community building coordinator as a priority. Selection 
of LHAs were over 25 years old, indigenous people from the same community, 
communicated in indigenous language and had a driver license of motorcycle or car. 
Subsequently, all LHAs received 4-week 15-hour curriculums of training. The training 
manual was developed to educate the LHAs about association of common oral diseases 
and systemic diseases in older people, oral care for the older people, teaching principles 
and methods, working log and practice and final is communication skill. After 4 weeks 

of training, 28 trainee LHAs passed the qualification exam and became certified LHAs. 
2.6 Intervention 
Oral exercise intervention is designed to increase the range of movement in tongue, 
lips, and jaw as well as salivary gland massages, which will help speech and/or swallow 
functioning. All participants performed oral exercise before three meals a day, whereas 
the participants in the EG also received 4 lessons from a LHA over 4 weeks. Four 
lessons were taught one-on-one once a week by a certified LHA at the participants’ 
homes. The lessons including understand oral structure, learn oral self-care skills and 
oral function promotion, understand the status of oral self-care and the relationship 
between oral diseases and systemic diseases, understand swallowing dysfunction and 
safe eating skills and review. Teaching tool including oral health leaflets, oral exercise 
video, dental model, magnets, stickers and oral care logbook. The participants in the 
CG received leaflets only. 
2.7 Data collection 
Data were collected by thoroughly trained interviewers during face-to-face 
interviews in accordance with standard protocol. Each interviewer attended a 1-hour 
training course on the standard process and data collection criteria before data 
collection. The data collection process comprised three steps. First, a dental hygienist 
recorded the PCR score, PI score, and tongue coating score. Second, a structured 
questionnaire was administered by an interviewer. The entire interview process took 
approximately 30 minutes. Finally, the research staff collected data on masticatory 
performance, assessed according to the results of participants chewing color-changing 
gum, and on /pa/, /ta/, and /ka/ syllables and swallowing. The inter-rater reliability for 
two dental hygienists was kappa=0.89.  
2.8 Statistical analysis  
Stata 13.1 (StataCorp LP, College Station, TX, USA) was used for statistical 

analysis. A chi-square test and two sample t test were used to compare the demographic 
variables of the EG and CG. A logistic regression model using generalized estimating 
equations (GEEs) analyzed the change in oral self-care behaviors between baseline and 
the follow-ups. Comparisons of OHQoL, oral function index, and dental hygiene index 
between the EG and CG were analyzed with a linear regression model using GEEs. The 
effect size (Cohen’s d) of continuous variables were calculated from the mean 
difference between baseline and the follow-ups within the EG and CG. An effect of 
0.20 is small, 0.50 is medium, and 0.80 is large [26]. 
 
 
 
 
 
 
 
 
The CONSORT flow chart of participant recruitment 

References 
1 
Nations U. Department of Economic and Social Affairs Population Dynamics, 
Revision 
of 
World 
Population 
Prospects 
2019; 
https://population.un.org/wpp2019/.  
2 
Council 
ND. 
Taiwan 
Executive 
Yuan, 
 
population 
estimation 
2020;https://www.ndc.gov.tw/Content_List.aspx?n=81ECE65E0F82773F.  
3 
Hagglund P, Koistinen S, Olai L et al. Older people with swallowing 
dysfunction and poor oral health are at greater risk of early death Community 
Dentist Oral Epidemiol 2019:8.  
4 
Ueno M, Yanagisawa T, Shinada K et al. Masticatory ability and functional 
tooth units in Japanese adults Journal of oral rehabilitation 2008;35:337-344.  
5 
Lin YC, Du JK, Lin PC et al. Association between the dental occlusion and 
perceived ability to eat foods of Taiwanese older adults Journal of oral 
rehabilitation 2021;48:817-826.  
6 
Lu T-Y, Chen J-H, Du J-K et al. Dysphagia and masticatory performance as a 
mediator of the xerostomia to quality of life relation in the older population 
BMC Geriatrics 2020;20:521.  
7 
de Silva AM, Martin-Kerry JM, McKee K et al. Caries and periodontal disease 
in Indigenous adults in Australia: a case of limited and non-contemporary data 
Australian health review : a publication of the Australian Hospital Association 
2017;41:469-478.  
8 
Durey A, Bessarab D, Slack-Smith L. The mouth as a site of structural 
inequalities; the experience of Aboriginal Australians Community dental health 
2016;33:161-163.  
9 
Sugiyama T, Ohkubo M, Honda Y et al. Effect of swallowing exercises in 
independent elderly The Bulletin of Tokyo Dental College 2013;54:109-115.  
10 
The health of indigenous Australians / edited by Neil Thomson. South 
Melbourne, Vic: Oxford University Press,2003. 
11 
Hsiao CN, Ting CC, Shieh TY et al. Relationship between betel quid chewing 
and radiographic alveolar bone loss among Taiwanese aboriginals: a 
retrospective study BMC Oral Health 2014;14:133.  
12 
Yang YH, Chen CH, Chang JS et al. Incidence rates of oral cancer and oral pre-
cancerous lesions in a 6-year follow-up study of a Taiwanese aboriginal 
community J Oral Pathol Med 2005;34:596-601.  
13 
Blanchard AK, Wang X, El-Gabalawy H et al. Oral health in a First Nations and 
a non-Aboriginal population in Manitoba International journal of circumpolar 
health 2012;71:17394.  
14 
George A, Villarosa AR, Ingram S et al. Oral health status, behaviours, food and 

beverage consumption of aboriginal children in Australia Health promotion 
journal of Australia : official journal of Australian Association of Health 
Promotion Professionals 2021;32:208-215.  
15 
Tynan A, Walker D, Tucker T et al. Factors influencing the perceived 
importance of oral health within a rural Aboriginal and Torres Strait Islander 
community in Australia BMC public health 2020;20:514.  
16 
Brownstein JN, Cheal N, Ackermann SP et al. Breast and cervical cancer 
screening in minority populations: a model for using lay health educators J 
Cancer Educ 1992;7:321-326.  
17 
Kegler MC, Malcoe LH. Results from a lay health advisor intervention to 
prevent lead poisoning among rural Native American children Am J Public 
Health 2004;94:1730-1735.  
18 
Plescia M, Groblewski M, Chavis L. A lay health advisor program to promote 
community capacity and change among change agents Health Promot Pract 
2008;9:434-439.  
19 
English KC, Merzel C, Moon-Howard J. Translating public health knowledge 
into practice: development of a lay health advisor perinatal tobacco cessation 
program Journal of public health management and practice : JPHMP 
2010;16:E9-e19.  
20 
Hood NE, Ferketich AK, Paskett ED et al. Treatment adherence in a lay health 
adviser intervention to treat tobacco dependence Health education research 
2013;28:72-82.  
21 
Kaphingst KA, Lachance CR, Gepp A et al. Educating underserved Latino 
communities about family health history using lay health advisors Public health 
genomics 2011;14:211-221.  
22 
Maxwell AE, Danao LL, Cayetano RT et al. Implementation of an evidence-
based intervention to promote colorectal cancer screening in community 
organizations: a cluster randomized trial Translational behavioral medicine 
2016;6:295-305.  
23 
Ritchwood TD, Dave G, Carthron DL et al. Adolescents and parental caregivers 
as lay health advisers in a community-based risk reduction intervention for 
youth: baseline data from Teach One, Reach One AIDS care 2016;28:537-542.  
24 
Lee H, Ho PS, Wang WC et al. Effectiveness of a health belief model 
intervention using a lay health advisor strategy on mouth self-examination and 
cancer screening in remote aboriginal communities: A randomized controlled 
trial Patient Educ Couns 2019;102:2263-2269.  
25 
Lin YC, Lin YC, Chen JH et al. Long-term effects of a lay health advisor 
intervention on immigrant children's dental caries and maternal preventive 

behaviour: A randomized controlled trial Community dentistry and oral 
epidemiology 2021.  
26 
Kotrlik J, Williams HA. The Incorporation of Effect Size in The Incorporation 
of Effect Size in Information Technology, Learning, Information Technology, 
Learning, and Performance Research and Performance Research, 2003. 
27 
Atchison KA, Dolan TA. Development of the Geriatric Oral Health Assessment 
Index J Dent Educ 1990;54:680-687.  
28 
Horiguchi S, Suzuki Y. Screening tests in evaluating swallowing function Japan 
Medical Association Journal 2011;54:31-34.  
29 
Fletcher SG. Time-by-count measurement of diadochokinetic syllable rate J 
Speech Hear Res 1972;15:763-770.  
30 
Wada S, Kawate N, Mizuma M. What Type of Food Can Older Adults 
Masticate?: Evaluation of Mastication Performance Using Color-Changeable 
Chewing Gum Dysphagia 2017;32:636-643.  
31 
Papadopoulou SL, Exarchakos G, Christodoulou D et al. Adaptation and 
Assessment of Reliability and Validity of the Greek Version of the Ohkuma 
Questionnaire for Dysphagia Screening Int Arch Otorhinolaryngol 2017;21:58-
65.  
32 
O'Leary TJ, Drake RB, Naylor JE. The plaque control record Journal of 
periodontology 1972;43:38.  
33 
Winkel EG, Roldán S, Van Winkelhoff AJ et al. Clinical effects of a new 
mouthrinse containing chlorhexidine, cetylpyridinium chloride and zinc-lactate 
on oral halitosis. A dual-center, double-blind placebo-controlled study Journal 
of clinical periodontology 2003;30:300-306.