Yearbook on Journal of the Japan Society of Nursing Research 2013

Development of Dysphagia Risk Assessment Scale for Elderly Living at Home
Junko Fukada 1), Yayoi Kamakura 1), Tadashi Kitaike 2), Masami Nojiri 2)
Key Words :dysphagia
risk assessment
development of scaleelderly living at home

ABSTRACTThis study aimed to develop a dysphagia risk assessment scale for the elderly living at home. The scale
was initially developed with 24 items, adopting a 4-grade answering method, focusing on dysphagia due
to aging and diseases, related aspiration, aspiration pneumonia, and malnutrition during the following 4
swallowing stages, excluding the anticipatory stage: oral preparatory stage; oral stage; pharyngeal stage;and esophageal stage. To select appropriate items from these, structured interviews were conducted with 81
elderly individuals living in facilities, while conducting a self-administered questionnaire survey, involving
658 elderly individuals living at home, to confirm their validity and reliability. Furthermore, a 3-ounce water
swallow test was performed as the gold standard.
Based on the results of content validity analysis, 17 items were selected for the scale. The validity of thescale was examined by performing factor analysis, and the following 4 factors were extracted: aspiration;
poor pharyngeal clearance; difficulty in posterior propulsion of bolus by the tongue and triggering thepharyngeal swallow; and esophageal dysphagia. The reliability of the scale was examined by performinginternal consistency analysis and adopting the retest method; Cronbach's alpha was 0.9 for the entire scale,with r=0.62 as test-retest reliability. The cut-off was set at 4, based on the ROC curve, with 57.1% sensitivity
and 69.6% specificity.
These results confirmed the validity and reliability of the scale consisting of 17 questions.

I. Introduction

and their families tend to be unaware of the presence ofdysphagia, and, even if they are aware of it, they frequently
regard occasional choking while eating as an inevitable,
natural, age-related symptom, rather than a problem toaddress. Considering such a situation, this study aimed todevelop a self-administered dysphagia risk assessment scale(scale), with a view to identifying the elderly living at homewith such risks and supporting them in the early stages.

Japan became classified as an aging society in 1994, andis currently becoming a super-aging society. It is important
for all Japanese people to know how to lead a healthy andindependent old age, and they commonly desire to maintaintheir eating skills even in their final days. On the other
hand, it has been reported that 12.7% of the elderly living
at home, aged 65 and over, have difficulty in swallowing
while eating, such as choking while eating rice, and theincidence of such symptoms increases with age1). In anotherstudy examining 56 elderly individuals without swallowing
difficulty, abnormalities were identified by videofluoroscopic(VF) examination of swallowing: oral stage: 63%; pharyngeal
stage: 25%; hypopharyngo-esophageal junction: 39%; andesophageal stage: 36%2). These findings suggest that theelderly living at home may be at risk of dysphagia during
daily activities. The presence of untreated dysphagia maylead to life-threatening problems, such as malnutrition,
dehydration, and choking. Furthermore, according to theAnnual of Pathological Autopsy Cases published by theJapanese Society of Pathology, 78.2% of those who died due
to aspiration pneumonia were aged 60 and over3); dysphagia
is closely associated with pneumonia and bronchitis as the
fourth leading cause of death in the elderly aged 65 and over.
Under such circumstances, it is necessary to establish social
systems to address the age-related incidence of dysphagia inthe elderly living at home; however, in Japan, dietary life isfrequently regarded as a domestic issue. In addition, the needs
assessment sheet used in the long-term care system contains
only 1 item related to swallowing: <Possible to appropriately
swallow; requiring assistance; or impossible to swallow>.
Although detailed dysphagia assessment is performed bymunicipalities, social support for the prevention and early
identification of dysphagia remains insufficient. The elderly

II. Methods

1. Development of a dysphagia risk assessment scale (Figure 1)
Ingestion is generally classified into 5 stages: anticipatory
stage; oral preparatory stage; oral stage; pharyngeal stage;and esophageal stage 4). Up to the present, dysphagia has been
examined based on this classification. Aiming to develop a
self-administered assessment scale, this study focused on
dysphagia during the oral, pharyngeal, and esophageal
stages, and that during the anticipatory stage, associated withdifficulty in recognizing food due to cognitive dysfunction,such as emotional incontinence and dementia, was excluded.
Logemann5) classified the factors influencing the swallowing
mechanism as follows: primary: the aging process;secondary: the course of diseases in the elderly; and tertiary:environmental, social, and psychological issues. This study
examined the primary and secondary influencing factors; inshort, dysphagia related to aging and diseases was classified
into the oral preparatory, oral, pharyngeal, and esophageal
stages. Also, considering the possibility of dysphagia being
complicated with aspiration, aspiration pneumonia, andmalnutrition, these items were also included in the initialscale.
Subsequently, based on the literature6-12), subjective
symptoms due to age- and disease-related dysphagia during
the oral preparatory, oral, pharyngeal, and esophageal stages
were included in the scale. Oral preparatory dysphagia
included symptoms influencing the subsequent oral stages,
such as oral dryness, incomplete lip closure, and difficulty inbolus formation. Similarly, that during the following stages

1) Aichi Prefectual College of Nursing &Health2) Chiba University, School of Nursing

Corresponding author. Tel.: +81 52 778 7105; Fax: +81 52 736 1415.
E-mail address: fukajun@nrs.aichi-pu.ac.jp (J. Fukada)

47
This paper was published at “the Japan Society of Nursing Research” Vol.25 No.1 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2013
Primary in�luencing factor
aging

Secondary in�luencing factor
diseases

Oral preparatory and oral
dysphagia

Pharyngeal dysphagia

Esophageal dysphagia

O1: Oral dryness
O2: Reduced lip closure
O3: Reduced lingual-buccal
tension coordination
O4: Reduced posterior
propulsion of bolus by the
tongueP1: Reduced nasopharyngeal closure
P2: Reduced glottic closure
P3: Delay in triggering the pharyngeal
swallow and dif�iculty in bolus
formation (liquid)
P4: Delay in triggering the pharyngeal
swallow and dif�iculty in bolus
formation (solid)
P5: Delay in triggering the pharyngeal
swallow and bolus retention in theepiglottic vallecula
P6: Residue in the epiglottic valleculaand pyriform sinus
P7: Residue in the laryngeal vestibule

E1: Gastroesophageal re�lux
E2: Residue in the esophagus
E3: Esophagitis

Malnutrition
M1: Decrease in the body weight
M2: Decrease in the volume of
dietary intake

Aspiration

Aspiration
pneumonia
Pn1: Pneumonia

A1: Aspiration before swallowing
A2: Aspiration during swallowing
A3: Aspiration after swallowing
A4: Aspiration while swallowing
liquids
A5: Aspiration while swallowing
solid foodA6: Aspiration while sipping soup
A7: Aspiration when swallowing

Figure 1. Construct and Questions of the Scale

researchers’ instructions, were studied. Structured interviews
were initially conducted to examine the appropriateness ofeach question, focusing on the participants’ comprehensionof its content and the incidence of dysphagia. Subsequently,
to confirm the validity and reliability of the scale, a selfadministered questionnaire survey was conducted. To
determine the gold standard, a 3-ounce water swallow
test17) was also performed. The details of each procedure aredescribed below.

included: oral dysphagia: difficulty in posterior propulsion ofbolus by the tongue and coordinating the lingual and buccal
tension; pharyngeal dysphagia: nasopharyngeal and glottic
insufficiency; a delay in triggering the pharyngeal swallow;
and poor pharyngeal clearance (bolus retention in theepiglottic vallecula, pyriform sinus, and laryngeal vestibule);
and esophageal dysphagia: gastro-esophageal reflux; bolus
retention in the esophagus; and esophagitis. Furthermore,
adopting the classification by Logemann12), aspiration wasclassified into before, during, and after swallowing to facilitate
the elderly’s self-assessment of aspiration while eating.
As the symptoms of dysphagia and aspiration vary,depending on the types of food, 24 questions were developed,
including those when drinking and eating rice, based on theliterature1, 13-16). Among these questions, 4 (O1 to O4) wererelated to oral preparatory dysphagia, 7 (P1 to P7) wererelated to pharyngeal dysphagia, 3 (E1 to E3) were related
to esophageal dysphagia, and 7 (A1 to A7) were related toaspiration. To answer the questions, a 4-grade response
scale was adopted: <Always>; <Sometimes>; <Rarely>;and <Almost never>. In addition, 1 question related toaspiration pneumonia due to dysphagia (Pn1) and 2 related
to malnutrition (M1 and M2) were also included in the scale,with 2 possible responses: <Yes>; and <No>.

1) Ethical considerations

Before conducting the structured interviews and 3-ounce
water swallow test, the participants were provided withwritten explanations of the study objective, methods, andunconditional right to withdraw to obtain their consent forcooperation. Similar explanations were also added to the selfadministered questionnaire sheet, and respondents’ consent
to participate was obtained when they returned the sheet.
2) Structured interviews

The structured interviews were conducted with 53
residents of nursing homes for the elderly and 28 day-service
users, giving a total of 81 elderly individuals living in facilities(facility group), whose attributes were similar to those of theelderly living at home. Furthermore, after approximately 3 to
4 weeks, a retest was performed, involving 73 of them, whose
consent for cooperation was obtained.

2. Participants and methods

The elderly aged 60 and over, living in Owariasahi City,
Aichi, who were able to cooperate with the study, following the48

This paper was published at “the Japan Society of Nursing Research” Vol.25 No.1 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2013

replayed off-line, and the sounds were evaluated by 2 raters.
Intra-rater reliability was examined twice, with an intervalof 1 week, while inter-rater reliability was examined by the
researchers and a third person (a nurse with clinical experience of 5 years on the dysphagia ward). The kappa coefficients
representing intra- and inter-rater reliability were both 0.85.

3) Self-administered questionnaire survey

The self-administered questionnaire survey was conducted,
involving a total of 2,508 senior club members (at-homegroup). The questionnaire sheet contained the questions
selected based on the results of the above-mentioned
interviews. The study objective was initially explained at a
meeting of the association of senior clubs, and, after obtaining
members’ consent, the questionnaire sheets were distributed
to them through the chairman, with a return envelope
to submit responses. In principle, the elderly themselves
answered the questionnaire sheet; however, when it wasdifficult for them to do so for health-related reasons, theirclose relatives filled in the sheet, representing their opinions
as accurately as possible. One to 2 months after the survey,
a retest was performed, involving 90 whose consent forparticipation in the 3-ounce water swallow test was obtained.

5) Neurological examination

Neurological examination was conducted following thewater swallow test, involving 57 facility group members,
whose consent was obtained, to appropriately select thequestions. The presence/absence of impairment of cerebral
nerves (V, VII, IX, X, and XII) controlling oral, pharyngeal, andlaryngeal senses and movements during swallowing, were
examined.
3. Analysis

4) The 3-ounce water swallow test

In the questionnaire survey, among the 858 responses(response rate: 34.2%), 658 (valid response rate: 76.7%), in
which all items, including the name, age, and sex, and answers
to the scale questions, were analyzed. The answers to thequestions were scored, adopting the Likert scale method,
as follows: <Always>: 3; <Sometimes>: 2; <Rarely>: 1; and<Almost never>: 0. The statistical analysis software SPSS (Ver.
9.0 for Windows) was used, and the significance level was
set at 5%.

To determine the gold standard, a 3-ounce water swallow
test17) (water swallow test) was performed. In this test,
participants are instructed to drink 90 ml of water without
intervals, and those coughing due to aspiration during the test
or within the following 1 minute or wet hoarseness after thetest are considered to be at risk. The test for the 81 facility
group members was performed 1 week after the interviews,
and that for the 90 at-home group members, whose consent
was obtained during the questionnaire survey, was performed
1 to 2 months after the distribution of the questionnaire sheet.
During the test, the risks of dysphagia were assessed, withindices to confirm the reliability of this assessment, such as
the sounds of coughing due to aspiration, wet hoarseness,and sounds of breathing before and after swallowing withcervical auscultation, using the 8-ch Standard MacLab System,
PowerLab System Ver. 3.6/s, and GPAmp (ADInstruments).
The obtained data were input into a laptop computer. Whenmeasuring the sounds of coughing, a heart sound microphone
was attached to the right cervical region, where laryngeal
elevation during swallowing was not interfered with, and thesounds of breathing were audible with less of an influenceof the carotid pulse. The data were input into the computer
through the GPAmp System, with a range of 100 mv, frequency
bandwidth of DC~5 kHz, and sampling speed of 4K/s.
The test was performed 1 hour after a meal, while sitting ona chair in a quiet environment (temperature: 25.0±2.0 degrees
C). Denture users underwent the test with their dentures. The
sounds of breathing during rest and those when vocalizing<ah> were initially recorded. Subsequently, the following
instructions were given: “Please drink a cup of water completely at your own pace without intervals or taking the cup
away from the mouth. After drinking all the water, vocalize<ah>”; and “If you choke while drinking, or have difficulty incontinuously drinking, it is possible to stop”. After the explanation, the recording was resumed, while instructing the participants to start drinking a cup of water (normal temperature;
90 ml). After they finished drinking (when the cup was taken
away from the mouth, and the larynx fell), and breathed onceor twice, they were instructed to vocalize <ah> to confirm thepresence/absence of wet hoarseness. Furthermore, to confirm
the presence/absence of aspiration, the recording was continued for 1 minute after swallowing.
After the test, the data input into the computer were

III. Results

1. Participant attributes

The mean age±SD of facility group members was 78.0±7.6,
and that of at-home group members was 74.9±6.7. The
number of females was 51 (63.0%) in the facility and 382(58.1%) in the at-home group; it was higher than that of males
in both groups.
The number of those with a history of stroke, respiratory or
gastrointestinal disease, or Parkinson’s disease, which may be
a primary disease of dysphagia, was 20 (24.7%) in the facility
and 256 (38.9%) in the at-home group. The number of thoseusing drugs (antihypertensives, tranquilizers, and hypnotics)
involving side effects possibly affecting the swallowing function, such as oral dryness and decreased arousal levels, was
45 (55.6%) in the former and 331 (50.3%) in the latter group.
In both groups, 95% or more were independent in activities
of daily living. Rice was the staple food in 80% or more, anddenture users accounted for approximately 70%.
2. Selection of scale questions

1) Mean score, incidence, comprehension, and reproducibility(Table 1)

Based on the results of the interviews, the questions withthe following conditions were excluded: a low mean score
and incidence; incomprehensible; involving a large numberof complaints related to causes other than dysphagia; and a
low test-retest reproducibility.
Mean scores for the questions were within the range
between 0.02 and 0.49. The questions with a mean score of
0.10 or less were as follows: <P1: Food or liquid goes into
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This paper was published at “the Japan Society of Nursing Research” Vol.25 No.1 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2013

Table 1. Mean Score and Incidence for Each Question of the Dysphagia Risk Assessment Scale in the Facility Group (N=81)
Questions[Preparatory oral dysphagia]
O1 Feeling oral dryness.

O2 Dropping food from your mouth while eating.

O3 Food remains in your cheek after swallowing.

O4 Food remains on your tongue after swallowing.

[Pharyngeal dysphagia]
P1

P2

P3

P4

P5

P6

Food or liquid goes into your nasal cavity.

Becoming hoarse.

Difficulty in swallowing liquids.

Difficulty in swallowing rice.

Food becomes stuck in your throat.

0.49

0.26
0.77
0.09

0.02

0.30

0.12

0.22

0.17

1.00

0.59
1.04
0.39

0.16

0.75

0.53

0.69

0.52

8

1
8
0

0

3

2

3

0

6
3

(9.9)

12

(0.0)

0

(0.0)

(3.7)

(2.5)

(3.7)

(0.0)

(14.8)
(3.7)
(0.0)

5

(6.2)

1

(1.2)

3

(3.7)

5

(6.2)

4

12
14
1

2

5

2

3

4

(17.3)
(1.2)

(2.5)

(6.2)

(2.5)

(3.7)

(4.9)

(77.8)

77(95.1)

65
47

79

68

76

72

72

(58.0)(97.5)(84.0)(93.8)(88.9)(88.9)[Espphageal desphagia]
E1 Food and sour liquid comes back up into yourthroat from the stomach.
E2 Food becomes stuck in your esophagus.

(1.2)

3

(3.7)

77

(95.1)

0.23

0.60

1

(1.2)

4

(4.9)

8

(9.9)

68

(84.0)A1 Choking or coughing before swallowing.

0.32
0.19

0.77

3

(3.7)

6

(7.4)

5

(6.2)

67

(82.7)

E3

Having heartburn.

[Aspiration]

A2 Choking or coughing during swallowing.
A3 Choking or coughing after swallowing.

A4 Choking or coughing while swallowing liquids.
A5 Choking or coughing while swallowing rice.
A6 Choking or coughing while sipping soups.
A7 Awakened by coughing in the night.

[Aspiration pneumonia and malnutrition]
Pn1 Having a history of pneumonia.

0.41
0.12
0.38
0.16
0.11
0.12

M1 Losing weight.

0.48
0.67
0.40
0.68
0.49
0.39
0.40

0
0
0
1
0
0
0
0
8

M2 Food intake has decreased to one-half.

2

(0.0)
(0.0)
(0.0)
(1.2)
(0.0)
(0.0)
(0.0)

Yes

(0.0)
(9.9)
(2.5)

(4.9)

3

(3.7)

8
2
2
2

81
73
79

No

(11.1)

16(19.8)

17

(4.9)

5

(7.4)

4

(2.5)
(2.5)

(100.0)

(4.9)

9

(9.9)
(2.5)

6

4

6
5
6

(21.0)
(7.4)
(6.2)
(6.2)
(7.4)

77

(80.2)

(0.0)

4

(4.9)

63

0

(0.0)

4

(4.9)

(14.8)

Almost never

1

0

(0.0)

3

(7.4)

(3.7)

Rarely

(0.0)

0.48

0

(9.9)

(1.2)

Sometimes

0

0.15

0.22

Always0.29

Becoming hoarse while or after eating.

0.05

±SD

0.06

P7

Food remains in your throat.

Mean

73
69
56
73
58
72
73
73

(95.1)(90.1)(85.2)(69.1)(90.1)(71.6)(88.9)(90.1)(90.1)(90.1)(97.5)(Note) Mean scores and SDs were calculated by scoring each answer as follows: <Always>: 3; <Sometimes>: 2; <Rarely>: 1; and <Almost never>: 0.
The numbers in brackets represent ratios of totals.

your nasal cavity>; <P6: Food remains in your throat >; <P7:
Becoming hoarse while or after eating >; and <O4: Foodremains on your tongue after swallowing >. The rates ofanswering <Always>, <Sometimes>, <Rarely>, or <Yes>
were within the range between 2.5 and 42.0%; the rate was
5% or less for the following questions: Pl; O4; P6; P7; <Pn1:
Having a history of pneumonia>; and <M2: Food intake has
decreased to one-half>. Questions Pn1 and M2, for which
the incidence was very low, were excluded. The mean score
and incidence were lowest for <P1: Food or liquid goes into
your nasal cavity>, showing no association with soft palatedeviation while vocalizing on neurological examination;
however, this question was not excluded, as it represented
dysfunction of nasopharyngeal closure, and there was a few
responses to it. Among the 4 respondents who answered<Sometimes> or <Rarely> to <O4: Food remains on yourtongue after swallowing>, 1 was diagnosed with lingual
motor impairment on neurological examination. Also, amongthe 4 who answered <Sometimes> or <Rarely> to <P6: Foodremains in your throat> or <P7: Becoming hoarse while orafter eating>, wet hoarseness was identified in 2 (P6) and 3(P7), respectively, during the water swallow test. Based on

50

these results, O4, P6, and P7 were considered to be associatedwith the neurological findings, and were selected.
Regarding respondents’ comprehension of the questions, it
was difficult for them to differentiate the symptoms describedas <P2: Becoming hoarse> and <A7: Awakened by coughingin the night> from those of the common cold, requiring therevision of these expressions.
On the other hand, while the mean score for <O3: Foodremains in your cheek after swallowing> was high, a large
number of respondents answered that such a symptom
occurred depending on the conditions of dentures. The
answers to <A6: Choking or coughing while sipping soups >also varied, as some did not sip soups, and such a variation
was related to eating habits. To <M1: Losing weight>and <M2: Food intake has decreased to one-half>, most
respondents answered that such symptoms occurred due
to other causes, such as the common cold. The questions
involving complaints related to causes other than dysphagia,
such as dentures, eating habits, and the common cold, wereregarded as inappropriate for the scale to assess the risks ofdysphagia, and were excluded.
The questions with a test-retest concordance rate of lessThis paper was published at “the Japan Society of Nursing Research” Vol.25 No.1 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2013

Table 2: Factor Structure of the Dysphagia Risk Assessment Scale (Major Factor Method with Varimax Rotation)
Questions

A2 Choking or coughing during swallowing.

Factor 2

Factor 3

Factor 4

.700

.117

.299

.148

.828

A3 Choking or coughing after swallowing.

A1 Choking or coughing before swallowing.

.682

A5 Choking or coughing while swallowing rice.

.577

A4 Choking or coughing while swallowing liquids.

.538

P6 Food remains in your throat.

.222

P5 Food becomes stuck in your throat.

.249

P7 Becoming hoarse while or after eating.

.257

P1 Food or liquid goes into your nasal cavity.

.341

O4 Food remains on your tongue after swallowing.

.182

P4 Difficulty in swallowing rice.

.312

P3 Difficulty in swallowing liquids.

.275

O2 Dropping food from your mouth while eating.
O1 Feeling oral dryness.

Questions

Factor 1

.208

.223

.300

.367

.277

.751

.631

.469

.384

.296

.448

.491

.047

.191

.155

.301

.279

.238

.291

.123

.331

.659

.596

.524

.485

.419

.048

.136

.197

.254

.270

.197

.119

.130

.144

.120

.140

.225

.198

.104

.640

Eigenvalue

2.90

2.40

2.16

1.66

Contribution (%)

Cumulative contribution (%)

17.1
17.1

.343

14.1
31.1

.133

.133

.130

.135

.087

.187

E3 Having heartburn.
E1 Food and sour liquid comes back up into your throat from the stomach.

E2 Food becomes stuck in your esophagus.

.087

.153

.263

12.7
43.9

.732

.548

Commonality
.762

.615

.582

.577

.483

.734

.617

.340

.388

.572

.674

.606

.300

.312

.568

.477

.505

9.8

53.6

On item-total (I-T) correlation analysis, the correlation coefficient between the total score and each of the 17 questions,excluding P2 and A7, was calculated; the coefficients were
within the range between 0.5 and 0.75.
Based on these results, the 17 questions, excluding P2 andA7, were considered to have sufficient content validity, andwere adopted for the dysphagia risk assessment scale.

than 70% were as follows: <A2: Choking or coughing during
swallowing>: 63.0%; <O3: Food remains in your cheek afterswallowing>: 65.8%; <P2: Becoming hoarse>: 67.1%; and<A4: Choking or coughing while swallowing liquids>: 68.5%.
Question O3 showed a low reproducibility, presumably due tothe influences of denture conditions. Questions A2 and P2 also
showed a low reproducibility, which may be associated withdifficulty in differentiating aspiration between before, during,
and after swallowing in the former, and in differentiating fromthe symptoms of the common cold in the latter.
For these reasons, Questions O3, A6, Pn1, Ml, and M2 were
excluded, and the remaining 19 were used for the following
self-administered questionnaire survey after the following
revision: A2: the phrases “before swallowing”, “during swallowing”, and “after swallowing” were emphasized with a wavy
line to facilitate differentiation; and P2 and A7: the phrase “inthe absence of the common cold” was added.

3. Construct validity of the scale (Table 2)

The scale’s construct initially consisted of: oral preparatory and oral dysphagia; pharyngeal dysphagia; esophageal
dysphagia; aspiration; aspiration pneumonia; and malnutrition. After the selection of the 17 questions, aspiration pneumonia and malnutrition were excluded. On factor analysis of
the results of the questionnaire survey (major factor methodwith varimax rotation), the following 4 factors were extracted:
Factor 1: 5 questions (A1 to A5) related to aspiration; Factor
2: 4 questions (Pl and P5 to P7) related to pharyngeal dysphagia, particularly indicating poor pharyngeal clearance; Factor
3: 3 questions (O1, O2, and O4) related to oral preparatory
and oral dysphagia associated with difficulty in posterior
propulsion of bolus by the tongue, and 2 questions (P3 andP4) related to pharyngeal dysphagia associated with a delay
in triggering the pharyngeal swallow; and Factor 4: 3 questions (E1 to E3) related to esophageal dysphagia. The factor
loading level was high for Factors 2 and 3 (P3 and P4). The 4
factors were defined as follows: Factor 1: aspiration; 2: poor
pharyngeal clearance; 3: difficulty in posterior propulsion ofbolus by the tongue and triggering the pharyngeal swallow;
and 4: esophageal dysphagia.
The correlation coefficient (r) between the total score for2) Content validity analysis

On factor analysis (major factor method) for the results of
the questionnaire survey, commonality was 0.275 for <P2:
Becoming hoarse in the absence of the common cold> and0.234 for <A7: Awakened by coughing in the night in theabsence of the common cold>; considering the commonalities of less than 0.3, these questions were excluded.
On good-poor (G-P) analysis, all participants were divided
into 2 groups, based on a mean total score of 3.1 for theremaining 17 questions, excluding Questions P2 and A7: highscore: 166 (25.2%); and low-score: 492 (74.8%). On the Wilcoxon rank sum test for each question, significant differences
between the 2 groups were observed in all questions.
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Yearbook on Journal of the Japan Society of Nursing Research 2013

all questions and that for the questions comprising each factor
was as follows: Factor 1: 0.84; 2: 0.84; 3: 0.85; and 4: 0.69.

A Receiver Operating Characteristic (ROC) curve was created based on the results of the water swallow test and total
score for the scale questions. The Y- and X-axes represent
sensitivity and 1-specificity, respectively. In the facility group,
when the cut-off was set at 2, both sensitivity and specificity
were 60% or more; however, based on the ROC curve (Figure2A), it was finally set at 4, as the upper left position closer tothe peak was considered theoretically more appropriate18).
On the other hand, in the at-home group, when the cut-off
was set at 2, sensitivity was 76.2%, while specificity was as
low as 37.7%. When it was set at 3 or 4, while high sensitivity
was similarly maintained, specificity was higher in the latter
case, 69.6%. In addition, in the ROC curve (Figure 2B), theupper left position close to the peak confirmed the appropriateness of this cut-off, and, therefore, it was also set at 4. Witha cut-off of 4, sensitivity and specificity were 59.1 and 75.9%,
respectively, in the facility and 57.1 and 69.6%, respectively,in the at-home group.

4. Reliability of the scale (Table 3)

On internal consistency analysis to confirm the reliabilityof the scale, Cronbach’s alpha was 0.90 for all questions, andthose for the 4 factors were within the range between 0.74
and 0.87.
Test-retest reliability was examined in comparison between
the facility (73; mean age: 77.7±7.6; involved in the interviews) and at-home (90; 74.6±6.8; involved in the questionnaire survey) groups by calculating the correlation coefficient
between the results of the initial and retests in relation to thefollowing items: total score for all questions; that for the questions comprising each factor; and score for each question. The
correlation coefficient (r) for the total score for all questions
was 0.82 in the facility and 0.62 in the at-home group. Thatfor each factor was 0.54 to 0.78 in the former and 0.49 to 0.69
in the latter group; Factors 1 and 2 showed a relatively low
correlation, with r=0.6 or less.
The questions with r=0.3 or less included: both groups:<P7: T Becoming hoarse while or after eating>; <A1: Choking
or coughing before swallowing>; and <A2: Choking or coughing during swallowing>; facility: <O4: Food remains on yourtongue after swallowing>; and <P1: Food or liquid goes into
your nasal cavity>; and at-home: <A3: Choking or coughing
after swallowing>.

IV. Discussion

In an aging society, it is desirable to support the elderly sothat they can continuously perform high-quality daily activities in order to lead a healthy, independent life, and normal
eating skills may be one of the requirements of such independence. On the other hand, the elderly are at an increased
risk of age-related dysphagia, in addition to diseases, and,
therefore, their conditions markedly vary among individuals.
In line with this, the early identification of a decreased swallowing function in the elderly living at home and early provision of support for them are crucial to improve the elderly’s
quality of life. Furthermore, since the Long-term Care Insurance System was initiated in 2000, difficulty in assessing theswallowing-related questions of the needs assessment sheet
has been pointed out, highlighting the social necessity of thedevelopment of appropriate dysphagia risk assessment scales.
Up to the present, although screening methods to assesspatients with cardiovascular impairment and neurologicaldiseases have been examined13, 19-23), no studies have focusedon the elderly living at home. The applicability of conventional
assessment scales to the elderly and their safety and accuracy
are discussed below:
The sensitivity and specificity of conventional clinicalassessment scales19-21) to examine symptoms during
swallowing, in addition to the labial, lingual, and laryngeal
functions, have been reported as follows: Splaingard, M.L. etal.19): 42 and 91%; Mari, F. et al.20): 74 and 74%; and Logemann,
J.A. et al.21): 78 and 58%, respectively. While these scales have

5. Sensitivity and specificity of the scale

The results of the water swallow test were as follows:
facility: aspiration: 9; wet hoarseness: 3; aspiration and wet
hoarseness: 9; and inadequate swallowing: 2. Among the 2
who withdrew, 1 had a history of gastrectomy, and had difficulty in completely drinking a cup of water in the presenceof gastroesophageal reflux. Also showing a slight but persistent fever of unknown origin, this participant was assessedas <with risks>. The other 1 was excluded due to difficultyin assessment. A total of 22 (27.5%) were assessed as <withrisks>. For the at-home group, the results were as follows:
aspiration: 9, wet hoarseness: 9; and aspiration and wet
hoarseness: 3. A total of 21 (23.3%) were assessed as <withrisks>.
Total scores for all 17 questions were within the range
between 0 and 51. The mean total score±SD was 3.5±4.8(range: 0-22) in the facility and 4.l±5.0 (0-24) in the at-homegroup; in both groups, the range peaked between 0 and 2.

Table 3: Reliability of the Dysphagia Risk Assessment Scale

Factor 1

Factor 2
Factor 3

Factor 4

Total score

Aspiration

Poor pharyngeal clearance
Difficulty in posterior propulsion of bolus by the tongue andtriggering the pharyngeal
Esophageal dysphagia

Internal consistency
Coefficient alpha
N=658
.87

.78

.76

.74

.90

Test-retest reliability
Facility group
At-home group
N=73
N=90
.54

.58

.72

.78

.82

.49

.51

.69

.60

.62

(Note)Test-retest reliability was examined by calculating the correlation coefficient between the results of the initial and retests, focusing on
the total score for the questions comprising each factor.

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Yearbook on Journal of the Japan Society of Nursing Research 2013

A. Facility group
1.00

Sensitivity

0.75

0.50

3-ounce water swallow test
(golden standard)
4

Score

2

4 or more
With risks

35Less than 4

0.25

0.00
0.00

0.25

0.50

0.75

With risks

Without risks

Total

13
(16.3)

14(17.5)

27(33.8)

944

53

Without risks(11.3)(55.0)(66.3)

Total

22(27.5)

58(72.5)

80(100.0)1.00

1-specificity

Sensitivity=59.1% and specificity=75.9%

B. Elderly living at home
1.00

3-ounce water swallow test
(golden standard)

Sensitivity

0.75

Score

3

0.50

5
0.25

0.00
0.00

0.25

With risks

Without risks

Total

4 or more
With risks

12(13.3)

21(23.3)

33(36.7)

Less than 4
Without risks

9(10.0)

48(53.3)

57(63.3)

Total

21(23.3)

69(76.7)

90(100.0)

2

4

0.50

0.75

1.00

1-specificity

Sensitivity=57.1% and specificity=69.6%

Figure 2. ROC Curve Showing Sensitivity and Specificity(Note) The numbers in brackets represent facility and at-home group members as a ratio of each total (N).

been shown to be noninvasive and safe, it is difficult to apply
them to all elderly individuals living at home, as their duration
is 30 minutes or more.
More convenient assessment methods include: the 30-ml
Water Swallow Test22); and Repetitive Saliva Swallowing
Test23). Considering that their duration is shorter than that of
the above-mentioned clinical assessment scales, they appear
to be more applicable to the elderly living at home, and, solely
using water, they may be safe. At the same time, it should be
noted that the 30-ml Water Swallow Test assesses the ability
to swallow 30 ml of water within 5 seconds without aspiration
by a single swallow. As it has been reported that some healthy
individuals need multiple swallows to drink water of 20 ml
or less24-26), and the maximum volume of water for healthy
individuals to completely drink by a single swallow is 20 ml27),
such a criterion may be questionable.
The Repetitive Saliva Swallowing Test focuses on thetriggering of the pharyngeal swallow, and, therefore, may
be inappropriate to assess dysphagia during the swallowing
stages other than the pharyngeal stage. It is also necessary
to consider that these clinical assessment scales and water
swallow tests require professional training for raters,
resulting in difficulty in obtaining sufficient levels of intraand inter-rater reliability.
The method developed by Fujishima et al.13) to assess
the history of pneumonia, nutritional state, and dysphagia
during the oral, pharyngeal, and esophageal stages, using aninterview sheet, may be regarded as safe. In addition, its level53

of accuracy is sufficiently high, with an alpha coefficient of
0.85, 92.0% sensitivity, and 90.1% specificity, and, therefore,
it may be more applicable to the elderly living at home,compared to the conventional clinical assessment scales;
however, to promote the healthy, independent lives of theelderly living at home, self-administered scales, which enable
them to assess their own swallowing function, and performself-care, such as maintaining or improving their eating skills,
may be more appropriate than those based on interviews.
In these respects, the conventional scales to assess patientswith cardiovascular impairment and neurological diseases
may be inappropriate to assess the risks of dysphagia inthe elderly living at home. It is necessary for dysphagia risk
assessment scales to evenly and comprehensively cover
not only aspiration and oral, pharyngeal, and esophageal
dysphagia, but also related pneumonia and malnutrition. The
scale developed in this study, with an appropriately set cut-off
as a dividing point for risk judgment, may facilitate the early
identification of those with risks of dysphagia. Furthermore,
adopting the self-administered method, it may be possible
for researchers to help the elderly become aware of theirown swallowing conditions by showing them their scores,
and perform self-care, such as maintaining or improving
their eating skills. In line with this, it may also be possible torecommend them to undergo VF, and, based on the results,
provide them with training for supraglottic swallowing orcompensatory postural techniques and nutritional guidance,such as changing the types of food.

This paper was published at “the Japan Society of Nursing Research” Vol.25 No.1 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2013

obtained, whereas the sensitivity was slightly lower,
indicating the necessity of addressing the following issues
for clinical application: the presence of questions with low
test-retest reliability; and the elderly’s insufficient knowledgeof dysphagia-related symptoms, as they stated that they had
never paid attention to such symptoms. In addition to theseissues, the exclusion of masticatory dysfunction during theoral preparatory stage, preceding the oral, pharyngeal, andesophageal stages, from the scale may also be associated withthis result, as mastication dysfunction leads to difficulty inpreparing the food bolus, and affects the subsequent swallow.
To increase the sensitivity of the scale to a sufficient level for
application, the questions should be reconsidered to cover
masticatory dysfunction. It may also be necessary to examine
more comprehensible expressions, while developing theelderly’s knowledge of age-related dysphagia.

For the scale, 17 questions were selected based on the
results of factor, G-P, and I-T correlation analyses to examinecontent validity. The 4 factors extracted through the factor
analysis: aspiration, poor pharyngeal clearance, difficulty inposterior propulsion of bolus by the tongue and triggering
the pharyngeal swallow, and esophageal dysphagia, may
be associated with the construct of the scale, consisting ofdysphagia during the oral preparatory, oral, pharyngeal,
and esophageal stages and aspiration, excluding aspiration
pneumonia and malnutrition. Also, considering the highcorrelation coefficients between the total score for allquestions and that for the questions comprising the 4 factors,
r=0.69 to 0.85, the scale is likely to have sufficient constructvalidity.
The overall reliability of the scale consisting of 17 questions
was also confirmed with a Cronbach’s alpha of 0.90, indicating
sufficient internal consistency; this meets the criterion forthe measurement of personal data, 0.9028). In addition, thetest-retest reliability level examined during the questionnaire
survey was as stable as r=0.62.
Based on these results, it may be appropriate to consider theentire scale to have sufficient construct validity and reliability,
and, therefore, the scale may be applicable to the elderly
who are able to subjectively evaluate their own symptoms
and answer the scale questions, or explain such symptoms
to their relatives. The evaluation time of approximately 10
minutes may also support its applicability to the elderly living
at home. Furthermore, being questionnaire-based, it may besafe, and may facilitate the determination of the presence/
absence of risks.
On the other hand, while the reliability of each factor of thescale was within the range between 0.74 and 0.87, meetingthe level necessary for group comparisons, 0.728), Factors 1
and 2 showed r=0.60 or less on the retest during both theinterviews and questionnaire survey, suggesting slightly
insufficient stability; this may be explained by the presenceof questions with a correlation coefficient (r) of 0.3 or less,rather than differences related to methods, such as interviews
and questionnaire surveys. Such questions included: Factor
1: <A1: Choking or coughing before swallowing>; <A2:
Choking or coughing during swallowing>; and <A3: Choking
or coughing after swallowing>; and Factor 2: <P1: Foodor liquid goes into your nasal cavity>; and <P7: Becoming
hoarse while or after eating>. The low correlation coefficientsfor Questions A1-A3 may be associated with difficulty indifferentiating between aspiration before, during, and afterswallowing, while those for Questions Pl and P7 may becaused by difficulty in realizing these symptoms due to a lackof experience in the elderly. Therefore, in order to increase
reliability, it may be necessary to reconsider the necessityof differentiating between aspiration before, during, andafter swallowing in the former, and enhance the elderly’s
knowledge regarding the occurrence of these symptoms ofdysphagia in the latter.
Based on the results of the water swallow test and total
scores of the scale, an ROC curve was created, and the cut-off
was set at 4 as a dividing point to determine the presence/
absence of risks of dysphagia: a total score of 4 or more:
with; and that of less than 4: without risks. With a cut-off
of 4, sensitivity and specificity were 59.1 and 75.9% in thefacility and 57.1 and 69.6% in the at-home group; comparedto the accuracy of the above-mentioned clinical assessment
scales used at the bedside20, 21), a similar specificity was

V. Conclusion

This study aimed to develop a dysphagia risk assessment
scale for the elderly living at home.
The scale was initially developed with 24 questions,adopting a 4-grade answering method, focusing on
dysphagia due to aging and diseases, related aspiration,
aspiration pneumonia, and malnutrition during thefollowing 4 swallowing stages, excluding the anticipatory
stage: oral preparatory stage; oral; stage pharyngeal stage;and esophageal stage. To select appropriate questions fromthese, structured interviews were conducted with 81 elderly
individuals living in facilities, followed by a self-administeredquestionnaire survey, involving 2,508 elderly individuals
living at home to confirm their validity and reliability. The
number of valid responses was 658. Furthermore, a 3-ounce
water swallow test was performed as the gold standard. The
results were as follows:
1. Based on the results of content validity analysis after theinterviews and questionnaire survey, 17 questions wereselected. On factor analysis, the following 4 factors wereextracted, confirming the construct validity of the scale:
Factor 1: aspiration; 2: poor pharyngeal clearance; 3: difficultyin posterior propulsion of bolus by the tongue and triggering
the pharyngeal swallow; and esophageal dysphagia.
2. Cronbach’s alpha, representing internal consistency, was0.90 for the entire scale, and the test-retest reliability was
r=0.82 in the facility and r=0.62 in the at-home group,
confirming the reliability of the scale.
3. Based on the ROC curve created in consideration of the total
scores and results of the water swallow test, the cut-off was
set at 4 to obtain 59.1% sensitivity and 75.9% specificity forthe facility, and 57.1% sensitivity and 69.6% specificity forthe at-home group.
Acknowledgement

The authors would like to thank all those who cooperated
with this study, including: Suketami Tominaga, the General
Manager of the Aichi Cancer Center; Ayako Mimizuka, theManager, and Shigeki Horibe, the Assistant Manager of the Section of Health Care, Department of Public Health, Owariasahi,
Aichi; senior club members; residents of nursing homes for theelderly; and day-service users. They would also like express
their sincere gratitude to Mie Asada of the Aichi Cancer Centerfor her assistance during the water swallow test.
54

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Yearbook on Journal of the Japan Society of Nursing Research 2013

References

16) Sonies, B. C., Parent, L. J., et al.: Durational aspects of the oralpharyngeal phase of swallow in normal adults. Dysphagia, 3:
1-10, 1988.
17) DePippo , K. L., Holas, M. A., et al.: Validation of the 3-oz water
swallow test for aspiration following stroke. Arch Neurol,
49:1259-1261, 1992.
18) Akira F.: 4 Health assessment and medical examination (Ed. O.,
Yoshiyuki): Text public health and preventive medicine. pp. 212221, NANZANDO Co., Ltd., Tokyo, 1996.
19) Splaingard, M. L., Hutchins,B., et al.: Aspiration in rehabilitation
patients: videfluroscopy vs bedside clinical assessment. Arch Phys
Med Rehabil, 69: 637-640, 1988.
20) Mari, F., Matei, M., et al.: Predictive value of clinical indices indetecting aspiration in patients with neurological disorders. J
Neurol Neurosurg Psychiatry, 63: 456-460, 1997.
21) Logemann, J. A., Veis, S., et al.: A screening procedure for oropharyngeal dysphagia. Dysphagia, 14: 44-51, 1999.
22) Toshio, K., Hironobu. M., et al.: Dysphagia paralytica in cerebrovascular disease: screening test and its clinical application. General
Rehabilitation, 10: 271-276，1982.
23) Eiichi S.: Provision of enjoyable meals and dietary guidance inconsideration of individuals’ abilities; A study as part of a healthpolicy research project led by the ministry of welfare in 1996
<Development of methods to diagnose eating dysfunction>,
37-58, 1997.
24) Yaoyoi, K., Junko, F., et al.: Effects of bolus volume and temperature on coordination of swallowing and respiration, The Japanese
Journal of Dysphagia Rehabilitation, 4(2)：40-48, 2000.
25) D ziadziola, J., Hamlet, S., et al.: Multiple swallows and piecemeal
deglutition; observations from normal adults and patients withhead and neck cancer. Dysphagia, 7: 8- 11, 1992.
26) Fanucci, A., Cerro, P., et al.: Ultrasonographic evaluation of piecemeal deglutition in normal adults. Dento-maxillo-facial-radiol.
26: 354-356, 1997.
27) Ertekin, C., Aydogdu, I., et al.: Piecemeal deglutition and dysphagia
limit in normal subjects and in patients with swallowing disorders. J Neurol Neurosurg Psychiatry, 61: 491-496, 1996.
28) Polit, D.F. & Hungler, B.P.: Nursing research principles and method.
trans. Junko K et al., pp.241-247, Igaku-Shoin Ltd., Tokyo,1994.

1) Yayoi, K., Kazushi, O., et al.: Swallowing function and daily activities in the elderly living at home; General Rehabilitation. 26(6):581-587, 1998.
2) Ekberg, O. & Feinberg, M. J.: Altered swallowing function in elderly
patients without dysphagia: radiologic findings in 56 cases. AJR,
156 1181-1184, 1991.
3) Toshio, I. & Koshu N.: Epidemiology of aspiration pneumonia.
Geriatr Med. 35: 129-133, 1997.
4) Leopold, N. A. & Kagel, M. C.: Swallowing, ingestion and dysphagia:
a reappraisal. Arch Phys Med Rehabil, 64: 371-373, 1983.
5) Logemann, J. A.: Effects of aging on the swallowing mechanism.
Otolaryngol Clin North Am, 23: 1045-1056, 1990.
6) Elliott, J. L.: Swallowing disorders in the elderly: a guide to diagnosis and treatment. Geriatrics, 43: 95-113, 1988.
7) Sonies, B. C.: Oropharyngeal dysphagia in the elderly. Clin Geriatr
Med, 8: 569-577, 1992.
8) Hiroshi, O., Shoko, I., et al.: Symposium 1: Pathophysiology of the
hypoparynx and esophagus in the geriatric age group. E. pharyngeal swallowing function in the elderly –videofluoroscopic
observations. J. Jpn. Bronchoesophagol., 42: 116-120, 1991.
9) Dejaeger, E., Pelemans, W., et al.: Manofluorographic analysis ofswallowing in the elderly. Dysphagia, 9: 156-161, 1994.
10) Sheth, N. & Diner, W. C.: Swallowing problems in the elderly. Dysphagia, 2: 209-215, 1988.
11) Feinberg, M. J. & Ekberg, O.: Videofluoroscopy in elderly patientswith aspiration: importance of evaluating both oral and pharyngeal stages of deglutition. AJR, 156: 293-296, 1991.
12) Logemann, J. A.: Evaluation and treatment of swallowing disorders, second edition, pp.77, PRO-ED, Texas, 1998.
13) Ichiro F., Ruri O., et al.: Development of questionnaires for eating
and swallowing disorders;An integrated study with a grant for
health sciences from the ministry of welfare, 1998.
14) Nathadwarawala, K. M., Nicklin, et al.: A timed test of swallowing
capacity for neurologial patients. J Neurol Neurosurg Psychiatry,
55: 822-825, 1992.
15) Groher, M.F.,：Rehabilitation for swallowing disorders associatedwith stroke. trans. Ichiro F, pp.116-120, Ishiyaku Publishers, Inc.,Tokyo, 1997.

55
This paper was published at “the Japan Society of Nursing Research” Vol.25 No.1 in 2002.