Okada et al.

Asian Pac J Dent 2019; 19: 77-84

Medical-dental and hospital-clinic collaboration in Iwate
Prefecture in Japan
Ayako Okada, DDS, PhD (1), Yoshiaki Nomura, DDS, PhD (1), Erika Kakuta, DDS, PhD (2),Ryoko Otsuka, DDS, PhD (1), Hiroshi Maekawa, DDS, PhD (3), Hideki Daikoku, DDS, PhD (3),Nobuhiro Hanada, DDS, PhD (1), and Tamotsu Sato DDS, PhD (3)(1) Department of Translational Research, Tsurumi University School of Dental Medicine, (2)Department of Oral Microbiology, Tsurumi University School of Dental Medicine, Yokohama, and (3)Iwate Dental Association, Morioka, Japan
Purpose: Japanese government has been promoted community-based integrated care systems which provide
seamless community healthcare resources for elderly people. In this system, medical-dental collaboration andhospital-clinic collaboration play important roles. In this study, to understand the actual the situation, survey was
conducted for the member of the Iwate Dental Association and analyzed the difficulty of the collaboration andthe regional differences.
Materials and Methods: The questionnaires were distributed to 609 all members of Iwate Dental Association.
Implementation of dental treatment for mentally handicapped patients, the experiences of dental treatment forpatients with diseases, the experiences of participated in nutrition support team and dental rounds at the hospital,
dental treatment after nutrition support team rounds, dental and oral care at the hospital or medical clinic,
participated in a collaborative conference at the hospital were surveyed. Data were analyzed by item response
theory and correspondence analysis.
Results: The 354 members retuned the questionnaire (collection rate was 58.1%). The 216/343 (61%) of dental
clinic had experienced the dental treatment of the patients with mental handicap. Participation of nutrition
support team and dental treatment after nutrition support ream round had high discrimination ability for the
medical and dental collaboration. By the correspondence analysis, regional differences can be observed.
Conclusion: There were the regional differences in the supply of the medical-dental and hospital-clinic
collaboration service in Iwate Prefecture. Providing information for the members of team approach may be oneof the resolutions for the regional difference.
(Asian Pac J Dent 2019; 19: 77-84.)
Key Words: hospital-clinic collaboration, medical-dental collaboration, medical plan, regional difference

Introduction
In Japanese super-aging society, the Japanese Ministry of Health, Labour and Welfare have promoted
community-based integrated care systems which provide seamless community healthcare resources for elderly
people with chronic diseases and disabilities [1,2]. By 2025, with the purpose of maintaining the dignity ofelderly people and supporting independent living, in the area where people can live as much as possible, people
can continue their own life to the end of life. In Japan, dental treatments have been mainly supplied by private
dental clinics. Hospital-clinic collaboration and medical-dental collaboration are important elements for theconstruction of community-based integrated care systems and promote the oral health of the elderly with chronic
diseases and disabilities.
Japanese Medical Service Act obligated every prefecture to design medical care plan according to their own
affairs for every five years. In this medical care plan, four diseases: cancer, cerebral apoplexy, acute myocardial
infarction, diabetes, and mental disease, have been focused on planning a seamless care plan in the community.
In this seamless care system, dentist plays an important role to promote the oral health and quality of life for thecommunity dowelling patients. Accumulated evidence of the effect of oral care for diseases support the role ofthe dentist. The implementation of oral care is beneficial for the prevention of oral mucositis duringchemotherapy, head, and neck radiation therapy, and hematopoietic stem cell transplantation [3]. Perioperative
oral management reduces the risk of surgical site infection after colorectal cancer surgery and shortens77

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Asian Pac J Dent 2019; 19: 77-84

postoperative hospital stay [4]. Starting professional oral care immediately after surgery and establishingeffective self-care may be important to prevent postoperative complications in patients with esophageal cancer[5]. Periodontal disease exerted on the cardiovascular system health and diabetes [6-8]. Individuals withdementia living in special facilities have more oral health problems than individuals without dementia [9].
Iwate prefecture is located northeast of Japan. It has the second largest area in Japanese prefecture. Statistics
Bureau, Ministry of Internal Affairs and Communications reported population density was 82.15/km2 at 2017.
Most of the areas are a rural area. Therefore, access to the regional core hospital is one of the barriers. Under
these conditions, to establish and promote primary health care system and regional comprehensive care system isimportant [10,11]. In "Health Iwate 21 plan (second stage)", the prevention of tooth loss andmaintenance/improvement of the oral function of elderly people and prevention of periodontal disease for thepatients with diabetes mellitus are listed as the basic direction. The basic stance of Iwate Health and Medical
Plan for visiting home dental care, dental treatment and oral care should be carried out under medical-dental
collaboration. Maintenance of oral function of elderly people and popularization and establishment of family
dentists has been also the aim of Medical Plan of Iwate Prefecture. The Iwate Dental Association is promoting
medical-dental collaboration by the collaboration with Iwate Prefecture Administration and Iwate Medical
Association. However, according to the Interim report of Health Plan 21 Iwate, not all of the dental clinics workon these collaborations.
In this study, to understand the actual situation of the medical-dental collaboration and hospital-clinic
collaboration, the survey was conducted for the member of Iwate Dental Association and analyzed the difficultyof the collaboration and the regional differences.

Materials and Methods
Study population
This study was a cross-sectional survey conducted using a self-administered postal questionnaire. The
questionnaires were distributed to 609 all members of Iwate Dental Association.
Questionnaire
The questionnaire consisted of 61 major categories including demographic factors, scales of the dental clinic,
visiting home dental treatment, medical-dental collaboration, and availability of services provided by Iwate
Dental Association for the members. Among these items, the following items were used for the analysis;
assignment in the branch, implementation of dental treatment for mentally handicapped patients (yes, no, could
not cope with), experience of dental treatment for patients with diseases (cancer, palliative care, diabetes mellitus,
heart disease, stroke, others). For the experience of participating in medical-dental collaboration was usedfollowing items; participated in nutrition support team (NST) and dental rounds at the hospital, dental treatment
after NST rounds, dental and oral care at the hospital or medical clinic, participated in a collaborative conferenceat the hospital, and never participate in the medical-dental collaboration.
Data analysis
Cross tabulations were carried out for each item against the branches in Iwate Dental Association. Under the
Item Response Theory (IRT) approach three parameters logistic model was applied [12-15]. Item difficulty, item
discrimination and item information were calculated. Item response curve and item information curves weregraphically illustrated. Analysis of IRT was performed by the R software with ltm and irtoys package. To

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visualize the relations, correspondence analysis was conducted. The results were expressed as biplot [16]. These
analyses were conducted with IBM SPSS Statistics version 24 and IBM Amos 24 (IBM Inc., Tokyo, Japan).
Ethics statement
The study was carried out in compliance with the principles of the Helsinki Declaration. Informed writtenconsent for publication was obtained from each subject when the questionnaires were returned. This study wasapproved by the Ethics Committee of Tsurumi University School of Dental Medicine (approval number: 430).

Results
The questionnaire was distributed for 609 all members of Iwate Dental Association and 343 retuned thequestionnaire (Tables 1 and 2). Collection rate was 56.3%. For the medical-dental corporation, 217 (61.3%)
dental clinics experienced the dental treatment of mentally-handicapped patients. Only 8 (2.3%) cannot copewith dental treatment for mentally-handicapped patients. As patients with cancer had many oral problems,
intensive oral care is recommended before the operation. Salivary flow drastically decreased for the patients
undertaken radiation therapy. Ministry of Health, Labour and Welfare consignment and registered the dentist
who has certificated the dental treatment and oral care for the patients with cancer. The 237 (69.0%) dental
clinics had experienced the dental treatment of patients with cancer. And most of the area, more than 60% of
dental clinics initiative worked on the dental treatment of the patients with cancer.
Table 1 Experience of dental treatment for mentally handicapped patients
Experience of dental treatment for mentally handicapped patients
Yes

No

Could not cope with

Total

Branch

n

%

n

%

n

%

Morioka

66

59

45

40

1

1

112

Iwate-Hachimantai

10

48

11

52

0

0

21

Miyako

17

81

3

14

1

5

21

Kamaishi

5

71

2

29

0

0

7

Toono

6

60

4

40

0

0

10

Shiwa

9

69

3

23

1

8

13

Hanamaki

15

71

6

29

0

0

21

Kitakami

16

62

9

35

1

4

26

Ousyu

24

65

11

30

2

5

37

Ichinoseki

21

60

12

34

2

6

35

Kesen

14

64

8

36

0

0

22

Kuji

6

75

2

25

0

0

8

Ninohe

7

70

3

30

0

0

10

216

63

119

35

8

2

343

Total

As the number of patients under palliative care was small, dental clinics in most of the branches had notexperienced the dental treatment of the patients under palliative care. However, 50% of the dental clinics in
Hanamaki branch and 75% in Kitakami branch had experienced the treatment.
Every prefecture is obligated to plan hospital and health planning for every 5 years. In hospital and healthplanning, Regional alliances clinical path for the patients with diabetes are included. However, less than 20% of
dental clinics in three areas had experienced dental treatment with diabetes and more than 40% of dental clinics
in six areas had experienced. For the dental treatment of patients with heart disease, around 30% of dental clinics
had experienced the dental treatment. The number of branches that more than 30% of dental clinics thatexperienced the dental treatment of the patients with stroke was only three.

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Table 2 Experience of dental treatment for patients with diseases
Palliative care

Diabetes mellitus

Heart disease

n

%

n

%

n

%

n

%

n

%

n

%

Morioka

59

69.4

16

18.8

35

41.2

27

31.8

19

22.4

10

11.8

Iwate-Hachimantai

15

78.9

4

21.1

6

31.6

7

36.8

3

15.8

1

5.3

Miyako

19

95

2

10

4

20

7

35

4

20

0

0

Kamaishi

2

33.3

2

33.3

3

50

2

33.3

2

33.3

0

0

Tono

6

75

0

0

4

50

6

75

2

25

0

0

Shiwa

9

90

0

0

4

40

5

50

4

40

0

0

Hanamaki

17

85

10

50

3

15

5

25

4

20

2

10

Kitakami

22

91.7

18

75

12

50

11

45.8

9

37.5

5

20.8

Oshu

36

100

6

16.7

11

30.6

9

25

6

16.7

0

0

Ichinoseki

29

87.9

10

30.3

14

42.4

7

21.2

6

18.2

2

6.1

Kesen

10

62.5

5

31.3

7

43.8

6

37.5

4

25

0

0

Kuji

7

87.5

1

12.5

1

12.5

3

37.5

1

12.5

0

0

Ninohe

5

83.3

0

0

2

33.3

2

33.3

1

16.7

0

0

236

81.1

74

21.5

106

30.9

97

28.3

65

19

20

5.8

BranchTotal

CancerStrokeOthersTable 3 Experience of medical-dental collaboration
Category

1

2

3

4

5

BranchMorioka

n

%

n

%

n

%

n

%

n

%

15

13.9

11

10.2

28

25.9

22

20.4

46

42.6

Iwate-Hachimantai

1

4.8

2

9

5

23.8

12

57.1

14

66.7

Miyako

3

13.6

2

9.1

10

45.5

11

50

17

77.3

Kamaishi

9

100

5

55.6

3

33.3

4

44.4

9

100

Toono

2

20

1

10

2

20

3

30

5

50

Shiwa

3

23.1

0

0

5

38.5

5

38.5

6

46.2

Hanamaki

20

95.2

13

61.9

13

61.9

9

42.9

21

100

Kitakami

20

76.9

15

57.7

14

53.8

16

61.5

22

84.6

Ousyu

33

86.8

16

42.1

15

39.5

13

34.2

36

94.7

Ichinoseki

7

18.9

6

16.2

13

35.1

14

37.8

22

59.5

Kesen

13

59.1

6

27.3

7

31.8

11

50

17

77.3

Kuji

0

0

0

0

2

25

5

62.5

6

75

Ninohe

9

81.8

6

54.5

4

36.4

5

45.5

10

90.9

Total
135
39.3
83
24.1
121
35.3
130
37.9
231
Category: 1) Participated in NST and dental rounds at the hospital; 2) Dental treatment after NST rounds;
3) Dental and oral care at hospital or medical clinic; 4) Participated in a collaborative conference at hospital;
5) Never participate in medical-dental collaboration. NST, Nutrition support team

67.3

Table 4 Three parameter logistic model for medical-dental collaboration(A) Experience of dental treatment for patients with diseases
Discrimination
Difficulty

Guessing(B) Experience of medical-dental collaboration
Category
Discrimination
Difficulty
Guessing

Mentally handicapped patients

12.27

1.25

0.3

1

16.95

0.94

Cancer

4.24

1.38

0.26

2

12.76

0.92

0.21
0.03

Palliative care

0.62

−2.3

0.01

3

1.63

0.59

0.0003Diabetes mellitus

1.73

−0.72

0.00002

4

1.02

0.68

0.01

Heart disease

3.22

−0.66

0.00001

Stroke

4.76

−0.95

0.00006

Others
0.29−9.75
0.04791
Category for (B): 1) Participated in NST and dental rounds at the hospital; 2) Dental treatment after NST rounds;
3) Dental and oral care at hospital or medical clinic; 4) Participated in a collaborative conference at hospital. NST, Nutrition support team

Table 3 shows the experience of the medical-dental corporation of the dental clinics by the branch. Large
regional differences existed. Less than 10% of dental clinics in four branches experienced attendance in NSTteam rounds and dental practice after NST rounds. More than 50% of dental clinics in six branches experienced
attendance in NST team rounds. The 231 (67.3%) dental clinics did not experience the medical-dental

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corporation. The rate of without experience was varied from 43.6% to 100% by the branch.
To evaluate the difficulty to participate in the medical-dental collaborations, three parameters logistic analysis
by Item Response Theory (IRT) approach were carried out. The models constructed are shown in Table 4 (A) for
the dental treatment for the patients with diseases and Table 4 (B) for the participation of medical-dental
collaborations.

Fig. 1 Item response curves and Item information curves for the experience of dental treatment for patients with diseases
Response scores were standardized from -4 to 4. Steep slope indicates high discrimination ability.

Fig. 2 Item response curves and Item information curves for the experience of medical-dental collaborations

The item response curves and item information curves are shown in Figs. 1 and 2. The item response curve ofthe dental treatment of the mentally handicapped patients and cancer showed a similar pattern and the item
response curves of cancer, heart disease, and stroke showed a similar pattern. The item response curve of thedental treatment of patients with palliative care showed a loose slope. From the item information curve of the81

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Asian Pac J Dent 2019; 19: 77-84

mentally handicapped patient, implementation of dental treatment of mentally handicapped patient clearly
distinguish the high levels of participation of medical-dental collaborations.
For the difficulty of the participation in medical-dental collaborations, item response curves of participated in
NST and dental rounds at the hospital and dental treatment after NST rounds showed steep curves. The item
information curves of these participation showed sharp slopes. The item response curves of dental and oral careat the hospital or medical clinic and participated in a collaborative conference at the hospital showed loose
slopes.

Fig. 3 Biplot of the branches of Iwate Dental Association and experience of dental treatment for the patients with diseases (left)
Regional differences were visualized by correspondence analysis and biplot. Red diamonds indicate the branch of Iwate Dental
Association and the blue circles indicate the experience of dental treatment for patients with diseases.
Fig. 4 Biplot of the branches of Iwate Dental Association and experience of medical-dental collaborations (right)
Red diamonds indicate the branch of Iwate Dental Association, and blue circles indicate experience of medical-dental
collaboration.

Figure 3 shows the biplot by the diseases and blanches. The regional difference could be observed for the
diseases. Figure 4 shows the biplot of the experience of medical-dental collaboration by the branch. There werebranches that advanced in NST collaboration, advanced in visiting dental care for the hospital and advanced injoint training with hospitals.

Discussion
In this study, difficulty and regional differences in medical-dental collaboration and hospital-clinic
collaborations in Iwate prefecture were analyzed. Clear regional differences could be observed. For the difficultyof dental treatment of the patient with diseases, dental treatment of the patients with mentally handicappedpatients and cancer were a difficult treatment. There are many barriers including human resources for dental
treatment of the patients with mentally handicapped patients [17-19]. There are many problems of oral healthinpatient with cancer [20]. For the dental treatment and oral care for patients with cancer, Ministry of Health,Labour and Welfare consignment and registered the dentist who is certificated. These facts may lead to thedifficulty of the dental treatment of these two diseases. However, Y values of mentally handicapped patients andcancer against −4 of X value was 0.3. It indicated that 30% of dental clinics that had almost no approach for
medical-dental collaborations experienced dental treatment for these two diseases. The Y value of patients withpalliative care against −4 of X value was also 0.3 and the slope of it was loose. It indicated patients who needpalliative care continuously attend or returned to their family dentist. It suggested that the system of family

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dentist works.
For the medical-dental collaboration, the Y value of item response curve of participated in NST and dental
rounds at the hospital against −4 was 0.2 and it continues to more than 0 value of X value. It indicated that there
may be some dental clinics that only to attend the round. The intercept of item response curves was less than 0.4.
It indicated that 40% of average levels for medical-dental collaboration tried no approach.
In Iwate prefecture, which has the second largest area in Japanese prefecture, the regional difference in the
supply of medical and dental services mainly derived from the difference of medical resources. The number ofregional core hospital in Iwate prefecture is 20 hospitals and 6 medical centers, which is highest in Japan.
However, there is a large difference in their scales. The differences were derived from the unbalance of humanresources. It resulted in the number of the medical department in the hospital and with or without regional
collaboration center. For the supply of dental services, the services supplied varied between the dental clinics.
Therefore, the dentist who participates in the medical-dental collaboration is fixed. However, according to theInterim report of Health Plan 21 Iwate, the major problem is the number of dentists is unbalanced between theareas.
For the areas that without dental department in regional core hospital, dental clinics need close collaboration
with regional core hospital. There are three types of collaborations: dentist participates in the NST, visiting
dental treatment and oral care for the inpatients in the hospital, and dental treatment and oral care before andafter hospitalization. For the participation in NST, the dentist needs to understand the nursing and nutrition by
on-the-job training. Training of the dentist is important to participate in the team approach. For visiting dental
treatment and oral care for the inpatients, calibration between dentists is important. In some cases, the dentist
needs to care of the patients after hospitalization. The dentist needs collaboration concerning the whole healthcontrol. For dental treatment and oral care before and after hospitalization, to control the team approach isimportant. Dentist needs collaboration with not an only the hospital but also the family of the patients. In
addition, if the nursing care is necessary at home, collaboration with visiting nurse and care manager is also
necessary. To establish the system including education and training of the dentist may be one of the resolutionsof the regional difference.
Dental care for patients with palliative care was advanced in two branches. There may be two major reasonsfor advancement. One is the medical doctors’ understanding of the importance of dental care for patients withpalliative care. The hospital that the medical doctor who understands the importance of dental care, dentist
participates in the NST and visiting dental treatment and oral care for the inpatients in the hospital were already
implemented. According to the Interim report of Health Plan 21 Iwate, another reason was that there were someareas that the regional core hospital did not set the palliative care ward. Moreover, in the regional core hospitalthat newly set the palliative care ward, the medical doctor often lacks the understanding of dental care for thepatients need palliative care. It led to the basic concept of the home dentist. To provide the information for
medical doctor may be one of the resolutions for the dissemination of dental treatment and oral care for thepatients under palliative care.
In conclusion, there were the regional differences in the supply of the medical-dental and hospital-clinic
collaboration service in Iwate prefecture. Providing information for the members of team approach may be oneof the resolutions for the regional difference.

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Acknowledgment
This work was supported by the annual fund of Iwate Dental Association.
Conflict of Interest
The authors declare no conflict of interest exists.

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Correspondence to:
Dr. Yoshiaki Nomura
Department of Translational Research, Tsurumi University School of Dental Medicine,
2-1-3, Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan
Fax: +81-45-573-2473 E-mail: nomura-y@tsurumi-u.ac.jp
Accepted November 25, 2019.
Copyright ©2019 by the Asian Pacific Journal of Dentistry.
Online ISSN 2185-3487, Print ISSN 2185-3479

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