保健医療科学

2017Vol.67 No.5 p.523－529＜ Original ＞

Factors affecting xerostomia among community residents participating
in a long-term care-prevention workshop: a cross-sectional study
Chieko Kubota 1), Yoko Uchida 2), Yohei Hama 3)
1)

Major of Oral Health Sciences Department of Health Development School of Health and Social Services Saitama
Prefectural University
2)
Graduate School of Health Sciences, Gunma University
3)
Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and
Dental University
Abstract
Objectives: This cross-sectional study aimed to determine the influence of selected background characteristics of community residents who participated in a long-term care-prevention workshop on the presence
and severity of xerostomia symptoms.
Methods: Of 1893 participants across 12 care-prevention workshops, 1137 participants gave written consent to participate in the survey. A self-administered questionnaire was administered. The main survey
items were background characteristics of the participants and the Xerostomia Inventory (XI).
Results: Factors found to affect oral dryness were age, medication use, sleep quality, constipation, and theuse of dentures. Xerostomia was also found to significantly influence quality of life.
Conclusions: When organizing long-term care-prevention workshops aimed at improving oral function, thebackground characteristics of participants should be taken into consideration.
keywords: xerostomia, long-term care, care-prevention, factors(accepted for publication, 31th October 2018)

I．Introduction
The aging population in Japan is steadily growing and,as a result, Japan ranks first among super-aged societies
worldwide[1]. Long-term care insurance was institutedin Japan in 2000, with system reforms applied in 2015.
These system reforms attempted to reduce the need forlong-term care through various care-prevention initiatives
that aimed to prevent the need for severe nursing care, as
the majority of the aging population needs only mild care.
These care-prevention initiatives include efforts intended
to improve musculoskeletal function, nutritional status, andoral function[2]. As the aging population expands and theburden of medical care and nursing care expenses increases, expectations for the effects of these workshops are also
increasing.
Specific activities that have been shown to be effectivein improving oral functionality include activities promoting
oral exercise and oral care, such as oral hygiene instruc-tion, facial and tongue muscle exercise, and salivary glandmassage[3,4]. These screening and evaluation methods
include the repeated saliva swallowing test (RSST) andfood test (FT), as well as intraoral examination performed
by a dentist. In recent years, mouth dryness has become
an evaluation item for oral cavity function, and the evaluation of mouth dryness can be performed using an objective
assessment such as the Saxon test[5] or subjective self-assessment. The Xerostomia Inventory (XI) is a subjective
scale based on patient reports of dry mouth experiences[6].
Studies of community residents have found that xerostomia is influenced by several factors, including age[7],sex[8], use of medications[9], the presence of a nervous or
mental disorder[10], and the use of removable dentures[11].
In a previous study, a significant positive correlation was
found between lower urinary tract symptoms (LUTS) andxerostomia[12]. This finding suggests that xerostomia could
be used as an indicator of various aspects of physical health,
not limited to oral function. It has also been reported that

Corresponding author: Yoko Uchida3-39-22 Showa-machi, Gunma 371-8514, Japan.
E-mail: yuchida@gunma-u.ac.jp

J. Natl. Inst. Public Health, 67 (5) : 2018

523

Chieko Kubota, Yoko Uchida, Yohei Hama
xerostomia affects self-perceived quality of life (QOL)[13].
However, the participants of these studies are often patients of dental clinics, and there is no research targeting local community residents who are participating in long-termcare prevention workshops. Participants of such workshops
tend to be very health-conscious and they typically try to
eat healthy food and pay attention to their health care to
maintain good health[14].
In the present study, we aimed to determine the association and influence of participant characteristics in relation
to xerostomia among community residents who participatedin long-term care-prevention workshops. The results ofour study will provide support for the integration of participantsʼ background characteristics into the development ofcare-prevention activities aimed at improving oral function.

II．Methods
1. Participants
A total of 1,893 individuals participated in 12 care-prevention workshops in Gunma Prefecture, and of these,
1,352 residents consented to study participation. To recruit
participants, we advertised the workshops on the bulletinboard of each municipality. Reason for non-participation
included individuals that did not agree with participating inthis research and those that did not stay until the end of theworkshop and so did not answer the questionnaire. Data
collection was performed from 11th March to 8th December
2014. We asked the group head of the area to extensively
advertise before the workshop and invite the participationof as many people as possible. Analyses were performedon participants who answered all 11 questions of the XI(n=1137).
2. Survey method and contents
1）Main survey items
Participants were asked to complete a self-administeredquestionnaire during the second half of the care-prevention
workshop. The majority of survey questions were “yes/no” and included items on background characteristics ofparticipants and self-reported experience of xerostomia.
Background data obtained included eight characteristics:
age, sex, hospital visits, medication use, denture use, regular exercise, sleep quality, and constipation. These variables
are associated with xerostomia[7-11] and promoting independence and health of elderly community residents[14].
2）The Xerostomia Inventory (XI) scores
The XI is a widely used rating scale for assessing xerostomia (Table 2). Participant XI scores were derived
from self-reported answers to items on the XI[6]. The XI
contains 11 items: “I sip liquids to aid in swallowing food”;

524“My mouth feels dry when eating a meal”; “I get up at night
to drink”; “My mouth feels dry”; “I have difficulty eating
dry foods”; “I suck sweets or cough lollies to relieve drymouth”; “I have difficulties swallowing certain foods”; “Theskin of my face feels dry”; “My eyes feel dry”; “My lips feeldry”; and “The inside of my nose feels dry.” The study participants were then asked to indicate which one of the following five response options best described their symptoms
over the preceding two weeks. The response options were:“never” (score, 1); “hardly ever” (score, 2); “occasionally”(score, 3); “fairly often” (score, 4); or “very often” (score, 5)[6]. In addition, we added a single, unique item to the questionnaire related to QOL, which asked the participants how
much they felt xerostomia hindered their lives.
3. Analytical methods
We analyzed the relationship between XI scores and thefollowing characteristics, using the Mann-Whitney U test:sex (male or female), regular hospital visits, good sleep, andconstipation, talking medication, wearing denture. The relationship between age, complaints-xerostomia (QOL) andXI scores was analyzed using simple linear regression. Allvariables were entered in multiple linear regression model.
A p-value of <0.05 was considered statistically significant.
Analyses were performed using IBM SPSS Statistics software package (IBM SPSS version 22, Tokyo, Japan).
4. Ethical considerations
An oral explanation of the survey was provided to allparticipants. Participant consent was implied when thecompleted questionnaire sheet was returned. No individual
identifying information was collected, and the questionnaire
data were converted to numerical values for analysis. This
study was conducted in full accordance with the World Medical Association Declaration of Helsinki and approved by the
Epidemiology Ethics Committee from Gunma University of
Medical Sciences (22-4).

III．Results
1. Participantsʼ background data
Participantsʼ background data are shown in Table 1. Of
the 1,137 participants, 509 (44.8%) were ≤64 years old and610 (53.6%) were ≥65 years old. The majority of participants were female (n=964: 85.0%; males, n=170: 15.0%).
Approximately half of the participants regularly visited ahospital (n=551: 48.5%) and took medications (n=550:
48.4%). Most participants reported good sleep (n=931:
81.9%) and exercised regularly (n=703: 61.8%). Eighty participants (7.0%) suffered from constipation and about halfof the participants (n=560: 49.2%) did not have dentures.

J. Natl. Inst. Public Health, 67 (5) : 2018

Factors affecting xerostomia among community residents participating in a long-term care-prevention workshop: a cross-sectional study
Table1

Background characteristics of participants

60

n=1137
Items
Age

≤ 64
≥ 65
Not answer
Mean ± SD
Sex
malefemaleNot answer
Regular hospital visits
yesno
Not answer
Taking medication
yes
no
Not answer
Good sleep
yesnoNot answer
Regular exercise
yesno
Not answer
Constipation
yes
no
Not answer
Wearing denture
no denture
dentureNot answer
Complaints-xerostomia
never
（QOL)
hardly everoccasionallyfairly oftenvery often
Not answer

ｎ
509
610
18
63 ± 12.7
170
964
3
551
553
33
550
548
39
931
170
36
703
408
26
80
1006
51
560
484
93
657
322
85
48
11
14

50

％
44.8
53.6
1.6

40

20

15.0
84.8
0.3
48.5
48.6
2.9
48.4
48.2
3.4
81.9
15.0
3.2
61.8
35.9
2.3
7.0
88.4
4.5
49.2
42.6
8.2
57.8
28.3
7.5
4.2
1.0
1.2

Table2y = -0.0425x + 24.76
R² = 0.0053

XI 30

10
0
0

20

40

60

80

100

age

Figure 1

Correlation of the Xerostomia Inventory
scores and age

60
50
40

XI

30
20
y = 4.3203x + 15.208
R² = 0.2605

10
0

0

1

Figure2

2

3

4

QOL

5

6

Correlation of the Xerostomia Inventory
scores and complaints-xerostomia(QOL）

Participantsʼ XI data
n=1137

Items

Never
ｎ

％

ｎ

％

ｎ

％

ｎ

％

ｎ

％

Mean

SD

Median1

I sip liquids to aid in swallowing food

418

36.8

266

23.4

217

19.1

129

11.3

107

9.4

2.3

1.3

2.0

2

My mouth feels dry wheneating a meal

639

56.2

278

24.5

134

11.8

69

6.1

17

1.5

1.7

1.0

1.0

3

I get up at night to drink

631

55.5

223

19.6

174

15.3

76

6.7

33

2.9

1.8

1.1

1.0

4

My mouth feels dry

424

37.3

260

22.9

298

26.2

128

11.3

27

2.4

2.2

1.1

2.0

5

I have difficulty in eating dry
foods

644

56.6

274

24.1

152

13.4

57

5.0

10

0.9

1.7

0.9

1.0

6

I suck sweets or coughlollies to relieve dry mouth

575

50.6

227

20.0

232

20.4

88

7.7

15

1.3

1.9

1.1

1.0

7

I have difficulties swallowing
certain foods

809

71.2

219

19.3

82

7.2

25

2.2

2

0.2

1.4

0.7

1.0

8

The skin of my face feels
dry

414

36.4

257

22.6

287

25.2

138

12.1

41

3.6

2.2

1.2

2.0

9

My eyes feel dry

435

38.3

213

18.7

273

24.0

161

14.2

55

4.8

2.3

1.2

2.0

10 My lips feel dry

350

30.8

234

20.6

329

28.9

181

15.9

43

3.8

2.4

1.2

2.0

452

39.8

263

23.1

270

23.7

118

10.4

34

3.0

2.1

1.1

2.0

11

The inside of my nose feels
dryscore=1

Hardy everscore=2 Occasionally score=3 Fairly often score=4

Very often

score=5

Abbreviations: SD, standard deviation

The majority of participants (n=657: 57.8%) reported thatxerostomia did not hinder their lives, while the remaining
participants (n=480: 42.2%) reported varying degrees ofhindrance.

the lowest percentage of “never (1 point)” was “My lips feeldry” (Table 2), which had a response of 350 participants(30.8%). However, the results showed that most participants had some symptoms of dry mouth.

2. Participantsʼ XI data
In the XI, which consists of 11 items, the question with

3. XI scores, QOL, and age (Table 3, Fig 1, Fig 2)
Age was a significant predictor of XI scores (B=-0.043,

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Chieko Kubota, Yoko Uchida, Yohei Hama
Table3Comparisons of the XI scores based on participantsʼ background characteristics

Items
Age

Sex
Regular hospital visits
Taking medication
Regular exercise
Good sleep
Constipation
Wearing denturemalefemale
yes
no
yes
no
yes
no
yes
no
yes
no
no denture
dentureXI scores
B (95% CI)-0.043(-0.077, -0.008)
XI scores
Mean
21.4
22.3
22.8
21.5
23.1
21.4
21.8
22.6
21.6
24.8
23.5
21.9
21.6
22.3

SD
7.5
7.3
7.6
7.1
7.7
7.0
7.3
7.4
7.3
7.6
8.6
7.2
6.9
7.5

R2
0.005

p-value
0.014

Median
21
22
22
21
22
21
21
22
22
24
21
21
21
21

p-value
0.114
0.043
0.004
0.032
p<0.001p<0.001
0.275

Analysis using the simple linear regression: Age
Mann-Whitney U test: except for age

Table4Multiple linear regression model of the XI scores

Predictors

B (95% CI)

p-value< 0.001Age-0.088 (-0.132, -0.043)

Sex

0.310 (-0.982, 1.601)

0.638

Regular hospital visits-0.381 (-2.137, 1.374)

0.670

Taking medication

2.251 (0.467, 4.035)

0.013

Regular exercise

0.211(-0.799, 1.221)

0.682Good sleep

2.523(1.220, 3.825)< 0.001

Constipation

3.107(1.360, 4.855)

0.001

Wearing denture

1.143(0.149, 2.138)

0.024

Model summary:

R2=0.066 F=8.126

Sex; 0: Males, 1: Females
Regular hospital visits; 0:no visits, 1: regular hospital visits
Taking medication; 0: no medication, 1: taking medication
Regular exercise; 0: regular exercise, 1: no regular exercise
Good sleep; 0: good sleep, 1: no good sleep
Constipation; 0: no constipation, 1: constipation
Wearing denture; 0: no denture, 1: wearing denture

95% CI: -0.077, -0.008, p=0.014) and XI scores was significantly correlated with QOL (B=4.320, 95% CI: 3.894, 4.747,
p＜0.001).
4. Comparisons of XI scores based on participant
background characteristics
Significant differences in XI scores were observed between sub-groups with the Mann-Whitney test (Table 3),classified according to the following background characteristics: age, regular hospital visits, medication use, regularexercise, sleep quality, constipation, and use of denture.
Participants who regularly visited a hospital scored signifi-

526

cantly higher on the XI scores compared to those who did
not. Medication users scored significantly higher on the XI
scores relative to non-medication users. Participants who
exercised regularly scored significantly higher than non-exercisers. Those who reported poor sleep quality scoredsignificantly higher on the XI scores compared to thosereporting good sleep quality. In addition, participants withconstipation scored significantly higher on the XI scorescompared to those without. When all variables were added
into a multiple linear regression model, age, medicationuse, good sleep, constipation, and denture use had a significant influence on the XI scores (Table 4).

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Factors affecting xerostomia among community residents participating in a long-term care-prevention workshop: a cross-sectional study

IV．Discussion
In the present study, significant differences in XI scores
were observed between participant sub-groups classified
according to age, medication use, sleep quality, constipation,and the use of denture. Specifically, participants under 65
years of age, who regularly visited a hospital, used medication(s), did not exercise regularly, suffered from poor
sleep quality, and experienced constipation reported greater
severity of xerostomia when compared to their respective
counterparts.
It has been demonstrated that dry mouth is a side effectof many medications[15]. Moreover, one study has foundthat saliva secretion is significantly reduced in individuals
who take two or more medications, compared to people
who take one or fewer[16]. The issue of polypharmacy iscurrently under vigorous debate[17]. Nevertheless, community residents participating in long-term care-prevention
workshops should be informed about this risk.
It has also been noted that individuals fitted with dentures report being dissatisfied with chewing and speaking[18]. Our finding – that the use of denture influences
xerostomia severity – is in accordance with these studies.
In dry mouth, mucous membranes are more likely to be
injured when wearing denture, and adsorption also deteriorates.
Our data also showed that high XI scores were morecommon among participants with poor sleep quality, andparticipants who experienced constipation. This seems tosignify that both physical and oral functions are reduced inindividuals who are unable to exercise. Movement of the
tongue in the oral cavity stimulates the salivary glands, andsaliva is secreted. Constipation commonly results from alack of water or a lack of exercise, both of which may predispose people to xerostomia. Our findings suggest thatexercise levels, sleep quality, and physical symptoms suchas xerostomia do not occur in isolation, but rather interact
with and mutually influence one another.
Many studies have found xerostomia to be more severein adults and elderly individuals[7-9]. In the present study,
however, we observed that participants under 64 years ofage scored higher on the XI than those aged 65 years orolder. One previous study reported that salivary flow rate
does not correlate with age[19], and age is not a directcause of saliva reduction. Elderly individuals tend to experience a decrease in saliva secretion due to the use of multiple medications or by being prone to systemic diseases that
may influence xerostomia. Therefore, workshops aimed
at improving oral function must consider participant background characteristics other than age in the developmentof care-prevention activities. Moreover, in designing work-

shops for improvement of oral cavity function, it is necessary to pay attention not only to the age of participants, butalso to the medications they are taking, their sleep quality,
and their excretory patterns.
When conducting care-prevention activities aimed at
improving oral function, professionals must consider attendeesʼ subjective evaluations of their own xerostomia in
addition to understanding attendeesʼ health in an integrated
manner, combining multiple aspects of their medical care.
These aspects of care include hospital visitation patterns
and the potential influence of the medications they are taking on various aspects of their lifestyle, such as exercise,sleep, and excretion. Recently, activities promoting preventative care in community residents have increased acrossJapan, as xerostomia is a common problem reported by elderly people[20]. Many care-prevention activities that havebeen developed separately focus on motor function, nutritional status, and oral function. Nutritional status is mutually related to both oral and motor functions[21]. Therefore, itwould be advantageous for all care-prevention activities toincorporate components of relevant health targets in a coordinated manner.
In the present study, a significant correlation was observed between participantsʼ XI scores and decreased QOL.
Factors that lower QOL are not limited to the feeling of dry
mouth, but may also include LUTS and constipation[22].
People participating in care-prevention activities may potentially have a physical disorder that involves xerostomia.
Professionals engaged in the provision of health and medical care must develop care-prevention activities from theperspective of improving the comprehensive health andlifestyles of participants, while taking into account the specific characteristics of each community.
One limitation of this research was a selection bias, since
the participants were volunteers who could come to the research venue, and their behavior may differ from the people
who would not, or could not attend. People who could notattend may not be interested in the health issues discussed
because they may not have ever encountered any healthproblems. The present study utilized a cross-sectional research design. As such, causal relationships could not beestablished. In the future, we aim to carry out a longitudinal
study to examine the factors related to xerostomia.

Ⅴ．Conclusions
Background conditions of the local residents participatingin the workshops, such as age, denture use, sleep quality,
and medication use, affected self-reported symptoms of xerostomia.

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527

Chieko Kubota, Yoko Uchida, Yohei Hama

Acknowledgments
We gratefully acknowledge the community residents forparticipating in this study.

Conflict of Interest
None declared.

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Factors affecting xerostomia among community residents participating in a long-term care-prevention workshop: a cross-sectional study

介護予防研修会に参加する地域住民の口腔乾燥に影響する背景条件：横断研究久保田チエコ 1），内田陽子 2），濵洋平 3）1）

埼玉県立大学健康開発学科口腔保健科学専攻2）

群馬大学大学院保健学研究科

3）

東京医科歯科大学大学院医歯学総合研究科高齢者歯科学分野

抄録
目的：本研究の目的は地域で開催される研修会に参加する地域住民の口腔乾燥感に影響する背景条件を明らかにすることである．
方法：対象は12ヶ所の介護予防研修会に参加した1893人のうち，調査に同意を得て口腔乾燥感一覧（XI）に回答した1137人とした．方法は自記式質問紙調査とし，主な調査項目は対象者の背景条件，
口腔乾燥感一覧（XI）とした．
結果：口腔乾燥感に影響する背景条件は，年齢，服薬，睡眠，便秘，義歯の有無であった．また，口腔乾燥感はQOLに影響を及ぼしていた．
結論：口腔機能の改善を目的とした長期介護予防ワークショップを開催する場合は，参加者の背景的特徴を考慮する必要がある．
キーワード：口腔乾燥感，長期療養ケア，介護予防，因子

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