Risk Factors and Prevalence of Deep Vein Thrombosis After the 2016 Kumamoto Earthquakes

Abstract

Background: After previous earthquakes, a high prevalence of deep vein thrombosis (DVT) has been reported. We examined DVT prevalence and risk factors in evacuees of the Kumamoto earthquakes by performing mobile DVT screening at various evacuation centers around the epicenter.

Methods and Results: For 1 month after the Kumamoto earthquake on 14 April 2016, mobile DVT screening using portable ultrasonography (US) was performed at 80 evacuation centers. Questionnaires, physical examination, and US of the lower limb were carried out, and simple D-dimer measurements were undertaken for DVT-positive examinees. The total number of examinees was 1,673, of whom 178 (10.6%) had DVT. The prevalence of DVT seemed to be gradually decreasing in the screening period, but age, use of sleep medication, prevalence of hypertension, dyslipidemia, leg edema, and lower leg varix were significantly higher in the DVT positive group than in the negative group. On multivariable logistic regression analysis, high age (≥70 years old), use of sleep medication, lower leg edema, and lower leg varix were significant predictors of DVT. In examinees with these 4 predictors, the DVT positive rate was 71.4%.

Conclusions: In the first month after the Kumamoto earthquakes, DVT prevalence and severity, evaluated on D-dimer level, decreased with the passage of time. Mobile DVT screening indicated significant factors stratifying DVT risk in the evacuees.

Kumamoto Prefecture in Japan was struck by a series of earthquakes (2016 Kumamoto earthquakes^1,2), including a magnitude (Mw) 6.5 on 14 April and Mw 7.3 on 16 April 2016. After these earthquakes, >180,000 people were evacuated to evacuation centers or private vehicles. More than 3,000 aftershocks prevented vast numbers of evacuees from returning home and forced many to stay for a prolonged period in cramped conditions to escape from collapsing homes.

The incidence of cardiovascular disease (hypertension,³ acute myocardial infarction,⁴ heart failure,⁴ pulmonary thromboembolism [PTE]^5,6 and deep vein thrombosis [DVT],⁵ and other cardiovascular diseases^3,7–9), stroke, and respiratory infections¹⁰ increases in evacuees after disasters. These concepts have been comprehensively reviewed.¹¹ The unsanitary environment of evacuation centers, sympathetic nervous tone, change in diet, sleep disorders, lack of water, and a shortage of drugs have been implicated as major causes of these diseases.⁹

DVT is defined as an interruption of blood flow through the deep veins because of formation of a thrombus or clot. DVT typically occurs after immobilization, surgery, or trauma, but also occurs in individuals with no obvious risk factors.^12–14 A high incidence of DVT in evacuees from an earthquake has been reported after previous earthquakes in Japan.¹⁵ Dehydration induced by limited water supply, prolonged immobility in a crowded evacuation center, and earthquake-related injuries are thought to be the causes of the high prevalence of DVT in evacuees from earthquakes.¹⁵ We have already demonstrated the risk and clinical significance of spending a night in a vehicle after a disaster, in order to prevent DVT.²

Based on these previous reports, we suspected a high prevalence of DVT and PTE in evacuees of the Kumamoto earthquakes. In situations where supplies and time are short at the acute phase of an earthquake, performing ultrasound (US) screening for DVT is unrealistic for evacuees. No detailed studies, however, have examined the risk factors of DVT using efficient screening in the acute–subacute phase after earthquakes. Therefore, the Kumamoto Earthquakes thrombosis and Embolism Protection (KEEP) Project was established by the cooperation of local medical institutions (Kumamoto City Hospital, Kumamoto University Hospital, Japanese Red Cross Kumamoto Hospital, Saiseikai Kumamoto Hospital, Kumamoto Chuo Hospital, and National Hospital Organization Kumamoto Medical Center), support organizations (National Cerebral and Cardiovascular Center, Japanese Circulation Society, Japanese College of Cardiology, Japanese Association of Medical Technologists, Japanese Society of Phlebology, The Japan Society of Ultrasonics in Medicine, Japanese Society of Echocardiography, and The Japan Society of Embolus Detection and Treatment), and public departments (Ministry of Health, Labour and Welfare, Kumamoto Prefectural Government, and Kumamoto City Government). We performed mobile screening of DVT in evacuation centers in Kumamoto Prefecture. We investigated the prevalence of DVT and risk factors of DVT in the acute–subacute phase after the Kumamoto earthquakes (between 19 April and 14 May 2016) as part of the KEEP Project.

Methods

For 1 month after the Kumamoto earthquake on 14 April 2016, between 19 April and 14 May, we performed mobile DVT screening in 80 evacuation centers in Kumamoto Prefecture. First, we selected examinees for lower limb US according to DVT risk factors, such as the number of days and nights in a vehicle, swelling, injury, or pain in the lower limbs, and physical inactivity. After a detailed medical interview and examination (measurement of blood pressure and oxygen saturation), US of the lower limbs was performed using portable US. The following equipment was used: Logiq e with a 4.2–13-MHz linear probe and V scan with a 3.4–8.0-MHz linear probe (GE Healthcare, Chicago, IL, USA); Acuson P500 with a 5–10-MHz linear probe and Acuson Freestyle with a 3–8-MHz linear probe (Siemens, Erlangen, Germany); Viamo with a 7.5-MHz linear probe (Toshiba, Tokyo, Japan); PAOLAS UF 760AG with a 5–12-MHz linear probe (Fukudadenshi, Tokyo, Japan); CX-50 with a 3–12-MHz linear probe (Philips, Amsterdam, Netherlands); SONIMAGE HS1 with a 4–18-MHz linear probe (Konica Minolta, Tokyo, Japan); and HS-1600 with 6–11-MHz linear probe (Hondadenshi, Toyohashi, Japan). US was undertaken from the popliteal fossa to the ankle, with the patient in the sitting position, and the presence of DVT was identified on non-compressibility or visualization of an intraluminal thrombus. We then measured the diameter of the soleus veins in both legs. Blood D-dimer, a degradation product of fibrin, was measured in evacuees who had DVT on blood sampling using a mobile D-dimer test kit (Cobas h232 POC System; Roche Diagnostics International, Rotkreuz, Switzerland). D-dimer >2.0 μg/mL was defined as severe DVT according to the DVT evaluations conducted for evacuees based on previous disasters, and the patients were referred to specialist hospitals as soon as possible.

In evacuation centers, examinations were performed after obtaining a signed consent form. This study was performed with the approval of the Kumamoto University Hospital Institutional Review Board (no. 1177).

Statistical Analysis

Data for normally distributed continuous variables are expressed as mean±SD, whereas those with a skewed distribution are expressed as median (IQR). Continuous variables were analyzed using the unpaired t-test. Categorical variables are shown as percentage and intergroup comparisons were analyzed using the chi-squared test. Relationships between the presence of DVT and other significant parameters in simple logistic analysis were determined by multivariable logistic regression analysis using the backward selection entry method (P<0.05 for inclusion). The Hosmer–Lemeshow goodness-of-fit statistic was calculated. P<0.05 denoted statistical significance and all tests were 2-tailed. Statistical analysis was performed using SPSS version 22.0 (IBM, Armonk, NY, USA).

This work was supported by a Grant-in-Aid from Japan Agency for Medical Research and Development (AMED; ID: 16lk1010009 h0001) and Grant Aid from Japanese Ministry of Health, Labor and Welfare (ID: 201605025A).

Results

Clinical Characteristics

We performed 1,738 examinations for evacuees of the Kumamoto earthquakes. The clinical characteristics of 1,673 examinees after exclusion of the second and subsequent examinations of the same subject are listed in Table 1. The average age was 70.4 years old and the proportion of women was 73.2%. Overall, DVT was detected in 178 examinees (10.6%).

Table 1. 2016 Kumamoto Earthquake Evacuee Characteristics (n=1,673)

	n=1,673
Age (years)	70.4±14.0
Female	1,225 (73.2)
Environmental factors and symptoms
Spent night in vehicle (days)	2.5 (0.0–3.0)
Slept on straw mat (days)	0.8 (0.0–0.0)
Slept on floor (days)	3.2 (0.0–5.0)
Sleep medication after earthquake	399 (23.8)
Lower leg symptoms	730 (43.6)
Palpitation or dyspnea	188 (11.2)
Lifestyle and past history
Fitness habits	793 (47.4)
Smoking habit	210 (12.6)
Drinking habit	206 (12.3)
Diabetes mellitus	263 (15.7)
Hypertension	858 (51.3)
Dyslipidemia	485 (29.0)
Malignancy	65 (3.9)
Heart disease	279 (16.7)
Ischemic heart disease	90 (5.4)
Arrhythmia	128 (7.7)
Anticoagulant therapy	113 (6.8)
Antiplatelet therapy	155 (9.2)
Hospitalization or maternity in ≤2 months	71 (4.2)
Hesitate to urinate	519 (31.0)
Objective findings
SBP (mmHg)	138.9±21.2
DBP (mmHg)	78.9±13.0
Heart rate (beats/min)	76.7±11.6
Percutaneous oxygen saturation (%)	97.4 (97.0–98.0)
Lower leg skin flare	15 (0.9)
Lower leg edema	130 (7.8)
Lower leg varix	302 (18.1)
Right calf size (cm)	33.2±3.8
Left calf size (cm)	33.2±3.9
Soleal vein diameter
Right (mm)	6.1±2.2
Left (mm)	6.2±2.1
DVT	178 (10.6)

Data given as mean±SD, n (%) or median (IQR). DBP, diastolic blood pressure; DVT, deep vein thrombosis; SBP, systolic blood pressure.

Prevalence of DVT and D-Dimer Distribution

Mobile DVT screening was carried out in various shelters, and time-series data were not obtained in the same examinee. The prevalence of DVT, however, gradually decreased from 33.3% on 19 April to 2.7% on 14 May (Figure 1). When the screening period was divided into separate weeks and the proportions of D-dimer levels evaluated (D-dimer <1 μg/mL, low group; 1–1.9 μg/mL, moderate group; and ≥2 μg/mL, severe group), the proportion of the low group gradually increased. Evacuees in the high group (≥2 μg/mL) were not observed in the fourth week (Figure 2).

Figure 1.

Prevalence of deep vein thrombosis (DVT) on cyclic screening from 19 April to 14 May 2016, after the 2016 Kumamoto earthquakes.

Figure 2.

Time course of D-dimer distribution in deep vein thrombosis (DVT)-positive evacuees in the 4 weeks after the 2016 Kumamoto earthquakes.

Evacuee Characteristics vs. DVT Status

Table 2 lists the clinical characteristics of the DVT-negative (n=1495, 89.4%) and DVT-positive (n=178, 10.6%) groups. Age (P<0.001), use of sleep medication (P=0.001), and the prevalence of hypertension (P=0.003), dyslipidemia (P=0.012), leg edema (P<0.001), and lower leg varices (P=0.002) were significantly higher, and soleal vein diameter on US (right, P<0.001; left, P=0.001) was significantly larger in the DVT-positive group than in the DVT-negative group.

Table 2. 2016 Kumamoto Earthquake Evacuee Characteristics vs. DVT Status

	DVT negative n=1,495 (89.4%)	DVT positive n=178 (10.6%)	P-value
Age (years)	69.7±14.2	76.1±9.9	<0.001
Female	1,084 (72.5)	141 (79.2)	0.094
Spent night in vehicle (days)	1.0 (0.0–3.0)	0.0 (0.0–2.0)	0.071
Slept on straw mat (days)	0.0 (0.0–0.0)	0.0 (0.0–0.0)	0.933
Slept on floor (days)	0.0 (0.0–5.0)	0.0 (0.0–6.0)	0.64
Sleep medication after earthquake	338 (22.6)	61 (34.3)	0.001
Lower leg symptoms	647 (43.3)	83 (46.6)	0.394
Palpitation or dyspnea	166 (11.1)	22 (12.4)	0.616
Fitness habits	709 (47.4)	84 (47.2)	0.936
Smoking habit	193 (12.9)	17 (9.6)	0.201
Drinking habit	188 (12.6)	18 (10.1)	0.344
Diabetes mellitus	237 (15.9)	26 (14.6)	0.666
Hypertension	748 (50.0)	110 (61.8)	0.003
Dyslipidemia	419 (28.0)	66 (37.1)	0.012
Malignancy	58 (3.9)	7 (3.9)	0.972
Heart disease	241 (16.1)	38 (21.3)	0.077
Ischemic heart disease	77 (5.2)	13 (7.3)	0.229
Arrhythmia	110 (7.4)	18 (10.1)	0.191
Anticoagulant therapy	99 (6.6)	14 (7.9)	0.532
Antiplatelet therapy	138 (9.2)	17 (9.6)	0.889
Hospitalization or maternity ≤2 months	63 (4.2)	8 (4.5)	0.861
Hesitate to urinate	472 (31.6)	47 (26.4)	0.159
Lower leg skin flare	12 (0.8)	3 (1.7)	0.238
Lower leg edema	104 (7.0)	26 (14.6)	<0.001
Lower leg varix	255 (17.1)	47 (26.4)	0.002
SBP (mmHg)	138.6±21.1	141.2±22.2	0.125
DBP (mmHg)	78.9±12.9	79.0±13.7	0.919
Heart rate (beats/min)	76.6±11.5	77.7±12.6	0.278
Percutaneous oxygen saturation (%)	98.0 (97.0–98.0)	97.0 (96.0–98.0)	0.18
Right calf size (cm)	33.2±3.8	33.2±3.9	0.987
Left calf size (cm)	33.2±3.8	33.1±4.5	0.834
Soleal vein diameter
Right (mm)	6.0±2.1	7.0±2.4	<0.001
Left (mm)	6.1±2.1	6.7±2.5	0.001

Data given as mean±SD, n (%) or median (IQR). Abbreviations as in Table 1.

Predictive Factors of DVT

On simple logistic regression analysis high age (≥70 years old), use of sleep medication, and the prevalence of hypertension, lower leg edema, and lower leg varices were significantly correlated with the presence of DVT. On multivariable logistic regression analysis, high age (OR, 1.849; 95% CI: 1.305–2.622; P=0.001), use of sleep medication (OR, 1.64; 95% CI: 1.167–2.306; P=0.004), lower leg edema (OR, 2.064; 95% CI: 1.290–3.303; P=0.003), and lower leg varices (OR, 1.593; 95% CI: 1.103–2.301; P=0.013) were significant predictors of DVT (Table 3). Hosmer–Lemeshow goodness-of-fit chi-squared was 0.946 with P=0.81.

Table 3. Indicators of DVT in Evacuees of the 2016 Kumamoto Earthquakes

	Simple regression analysis			Multivariable regression analysis
	OR	95% CI	P-value	OR	95% CI	P-value
Age >70 years (yes)	2.123	1.510–2.984	<0.001	1.849	1.305–2.622	0.001
Female (yes)	1.382	0.945–2.020	0.095		NS
Spent night in vehicle (days)	0.965	0.925–1.007	0.105		NS
Sleep medication (yes)	1.785	1.280–2.488	0.001	1.64	1.167–2.306	0.004
Hypertension (yes)	1.615	1.174–2.222	0.003		NS
Hesitate to urinate (yes)	0.778	0.548–1.104	0.16		NS
Lower leg edema (yes)	2.288	1.443–3.628	<0.001	2.064	1.290–3.303	0.003
Lower leg varix (yes)	1.745	1.218–2.499	0.002	1.593	1.103–2.301	0.013

Hosmer-Lemeshow goodness of fit: χ²=0.946, P=0.81. DVT, deep vein thrombosis; NS, not selected.

Derivation of DVT Risk Score

The DVT risk score was defined as the sum of 4 significant predictors of DVT, selected on multivariable logistic regression analysis: high age (≥70 years old), use of sleep medication, lower leg edema, and lower leg varices. The risk score was calculated based on the sum of predictors present in individual examinees. The distribution of the number of factors present and the corresponding prevalence of DVT are shown in Figure 3. The prevalence of DVT progressively increased with an increase in the risk score.

Figure 3.

Prevalence of deep vein thrombosis (DVT) risk score vs. the number of DVT-positive predictors (identified on multivariable logistic regression analysis) present in evacuees in the 4 weeks after the 2016 Kumamoto earthquakes.

Hospitalization for Severe DVT

When D-dimer exceeded 2.0 μg/mL in DVT-positive examinees, the examinees were referred to special hospitals to assess the systemic risk of thromboembolism. Of 16 evacuees with D-dimer >2.0 μg/mL, 3 required urgent hospitalization based on the judgment that hospitalization was necessary. One of the 3 patients (69-year-old man) was found to have the comorbidity of PTE. Therefore, 60 mg edoxaban was given after the initial heparin therapy, and hospitalization for 51 days was required. The others had DVT without PTE, requiring hospitalization for approximately 2 weeks.

Discussion

We investigated the prevalence and risk factors of DVT in evacuees of the Kumamoto earthquakes for 1 month after the onset of the first earthquake. We performed 1,673 US examinations, mainly at the evacuee centers in areas where damage was the greatest (i.e., in Mashiki Town in the eastern suburb of Kumamoto City and the East Ward of Kumamoto City). To the best of our knowledge, this is the first study on the prevalence and risk factors of DVT in the acute–subacute phase, with evacuees examined at the epicenter after the main earthquake and during continuing aftershocks.

In this study, the prevalence of DVT was 10.6%. The prevalence of DVT in healthy people is 2–4%,¹⁶ which is significantly lower than in the present study. Compared with previous reports on the prevalence of DVT after disasters,^15,17,18 the present result is considered to be appropriate.

In the present study the prevalence of DVT appeared to gradually decrease with time. In a previous study the prevalence of DVT gradually decreased, as in the present study, but it rose again after aggregation of data from all of the evacuation centers.¹⁵ Therefore, data need to be consolidated and analyzed >1 month after an earthquake. As described in the limitations section, careful examination is necessary because the present study was carried out using cyclic screening and did not include time-series data in the same examinee. Additionally, information on intervention for DVT after the earthquakes was extensively disseminated by the media (television, newspaper and Internet), and the environment of the evacuation centers gradually improved during the examination period.

Hanzawa et al reported that the risk of developing DVT increased with an increase in the number of days staying in private vehicles,¹⁷ but this was not observed in the present study. We suspect that mobile DVT screening did not include evacuees who spent the night in a vehicle because the screening was performed in the daytime. Furthermore, because the evacuees were classified as mainly spending the night in vehicles or staying in the evacuation center, especially in the acute phase, there were not many evacuees who stayed in vehicles at that time during the mobile DVT screening. There was no significant difference in the comorbidity of malignant tumors, which is considered to be a general risk factor of DVT,¹⁸ between the DVT-positive group and the DVT-negative group. On mobile screening there were not many critically ill patients because of the uncomfortable environment of the evacuation center. Therefore, the number of examinees might be insufficient to detect the significant correlation between DVT and malignant tumors.

On multivariable logistic regression analysis high age (≥70 years old), use of sleep medication, lower leg edema, and lower leg varices were significant predictors for DVT. Aging and lower leg varices are known risk factors of DVT,^19,20 consistent with the present results. Lower leg edema is considered to reflect blood flow disturbance by DVT. An association between the use of sleep medication after an earthquake and the onset of DVT has been reported in a small number of cases.²¹ Long-term immobility during sleeping and vasodilation effects due to the use of sleeping tablets, however, might be the cause of DVT. Various sleep medications with different mechanisms of action were used in the present study. Therefore, examining the details of sleep medication was difficult. Further studies are required on the relationship between the use of sleep medication and onset of DVT.

In this study, we calculated the DVT risk score using DVT-positive predictors identified on multivariable logistic regression analysis. A total of 71.4% of examinees who had all 4 factors of the DVT risk score had DVT. In situations where supply of human resources and equipment are insufficient at the time of a disaster, use of this scoring system may help stratify evacuees and provide medical resources appropriately.

Extensive routine US screening for DVT is not necessarily recommended according to the guidelines for the treatment of venous thromboembolism disease.²² With the use of mobile screening after earthquakes, however, we successfully identified 3 severe patients who required urgent hospital admission. Although there are no clear guidelines on prevention of venous thromboembolism disease after a disaster, efficient screening based on the 4 predictors clarified in this study may be useful for preventing occurrence of severe venous thromboembolism disease.

Lower limb DVT can occur as a proximal type and a distal type. In this study, we could not perform US of the proximal lower limb because it was not possible to set aside a private room for the protection of patient privacy in the evacuation center. As a result, it was not possible to evaluate the prevalence and risk factors of proximal DVT after earthquake in the present study. If the situation permits, the addition of proximal DVT examination after detection of distal DVT might be beneficial, because the relationship between D-dimer level and severity of DVT has not been validated, and US of the proximal lower limb is an inexpensive and safe technique compared with D-dimer measurement. Further investigation of proximal DVT occurring in evacuees after a disaster such as an earthquake is necessary.

Study Limitations

The present study had some limitations. First, we could not investigate all evacuees of the Kumamoto earthquakes. Because the present study was conducted for evacuees who were thought to be more likely to develop DVT, the true prevalence of DVT is considered to be lower than the present result. Second, the data were obtained on mobile screening of below-knee DVT screening, and were not obtained on follow-up of the same subject. Third, the total number of evacuees after the Kumamoto earthquakes was assumed to be approximately 180,000 people, therefore, we screened only a small proportion of the evacuees. Fourth, the data were obtained from mobile screening of below-knee DVT, and no screening of proximal or whole leg DVT was carried out.

Conclusions

In the first month after the Kumamoto earthquakes, the prevalence and severity of DVT, as evaluated using D-dimer, decreased over time. Of the examinee characteristics and clinical signs, high age, use of sleep medication, lower leg edema, and lower leg varices were independent significant predictors of DVT.

Acknowledgments

The authors thank Saki Ogata, Rina Usui, Kahoru Fujisue, and Shiori Kotegawa for data collection. We thank Ellen Knapp, PhD, from Edanz Group (www.edanzediting.com/ac) for editing a draft of this manuscript.

Disclosures

The authors declare no conflicts of interest.

Appendix

KEEP Project Organization

Principal Investigator: Seiji Hokimoto, Kumamoto University.

Steering Committee: Yoichiro Hashimoto, Kumamoto City Hospital (Chair), Makoto Nakajima, Sunao Kojima, Hiroshi Hosokawa, Kenji Sakamoto, Yohei Nagai, Kazuhirko Hanzawa, Sumio Masunaga, Shinji Tanka, Shoko Shimada, Kiyomi Kawasaki, Tomoko Higashi, Yuichiro Inatomi, Kazuteru Fujimoto, Katsuo Noda, Kazuhiro Nishigami, and Kohei Nagata.

Collaborators of the KEEP Project

Keijiro Saku, Mitsuaki Nagasawa, Shinsaku Ueda, Shinya Takase, Hirono Satokawa, Osamu Yamamura, Mituhiro Yoshida, Daisuke Sueta, Koichiro Fujisue, Yutaka Kai, Takeshi Ohgoh, Chieko Yamamoto, and Tami Yamamoto.

Data and Safety Monitoring Committee

Kenichi Tsujita, Yukio Ando, and Hisao Ogawa.

DVT Screening Investigators

Local Institutions and National Cerebral and Cardiovascular Center Koji Sato, Kenji Sakamoto, Masaya Fukuda, Hiroki Usuku, Fumie Kihara, Yuko Sakami, Emi Asamikawahara, Mayumi Ueno, Yousuke Emura, Yuji Ogata, Yoshiharu Saito, Tami Yamamoto, Kanako Imamura, Ayano Kido, Yui Kinoshita, Yuki Goto, Shinji Tanaka, Kayoko Sakai, Hiroshi Chiba, Kayoko Abe, Hiroki Kameyama, Kazumi Koga, Kyohei Marume, Masahiro Yamamoto, Shoji Kawakami, Akihiro Tsuji, and Hisao Ogawa.

Volunteers From the Japanese Circulation Society Taemi Akiyoshi, Reo Anai, Ichitaro Abe, Masaru Araki, Shinichi Ikegami, Yuki Ikebe, Tetsunori Ishikawa, Kenzo Ichimura, Toshiharu Umeki, Nanase Ozono, Keisuke Okamura, Ken Otsuji, Takahiro Oniki, Hidetaka Kaku, Hiroshi Kaminokawa, Goro Kawahara, Naoko Kitamura, Kayo Kimoto, Takuro Kubozono, Narumi Koga, Hisashi Koga, Hiroshi Kojima, Rie Koyoshi, Hideto Sako, Kyohei Sato, Akiyoshi Shimizu, Yoshitsugu Shirakawa, Yusuke Sugi, Yasuhiro Sedutsu, Susumu Takase, Masao Takahashi, Naoko Takayama, Takuro Takumi, Emiko Takeda, Kazuko Tajiri, Hideki Tashiro, Kazuhiro Tanaka, Hideto Chaen, Yuki Tsuda, Sayuri Tsuruda, Toshihiro Tsuruda, Kanako Doi, Tomoyuki Tobushi, Junichiro Nishi, Yume Nohara, Kaori Hara, Koji Higuchi, Akiko Fujiyama, Soshi Hei, Shiori Horikawa, Yoshihisa Horizoe, Masaaki Miyata, Joji Morii, Nagisa Morikawa, Natsumi Morito, Tomohiko Yamamoto, Toshinori Yuasa, Shingo Yunoue, Yuka Yoshimine, Satoshi Yoshimura, Issei Yoshimoto.

Dispatch From Japanese Association of Medical Technologists Kikuko Akimitsu, Emi Asamikawahara, Kayoko Abe, Yoshiteru Arimura, Mayumi Andou, Mariko Andou, Katsunori Bettou, Hiroshi Chiba, Yuji Chiba, Tamae Doi, Ayaka Eto, Kayoko Ebuchi, Yosuke Emura, Shota Fukushige, Masami Fukuda, Moe Fukunaga, Azusa Fukumitsu, Youko Fukuyoshi, Rika Fujita, Yutaro Fuchino, Kuniko Furukawa, Yuki Furukawa, Sanae Furushima, Asuka Goto, Yuki Goto, Shinsaku Hatake, Takama Hamano, Yasuko Hayashi, Takahiro Hayashida, Minako Haraguchi, Miho Harada, Shouichi Haruta, Yasuhito Hanba, Atsushi Higashi, Kohei Horikawa, Katsuyoshi Ikeda, Honami Ikeda, Taketoshi Izumi, Aiko Ide, Toshiaki Ide, Futoshi Ideguchi, Yuji Itou, Chizuru Imada, Ryuichi Imada, Kanako Imamura, Shigeo Iwahashi, Akari Kakino, Saori Kobayashi, Kenzo Komaru, Taeko Kondo, Fumika Kotou, Masahide Kakimoto, Yukiko Katou, Yukari Kamiyama, Hiroki Kameyama, Osamu Kawazu, Emiko Kawano, Takamichi Kitagawa, Naoko Kitamura, Ayano Kido, Fumiaki Kinoshita, Yui Kinoshita, Keiko Kudo, Miki Kubo, Yuko Kuratsuwa, Akiko Kurokawa, Kayo Kurokawa, Makoto Kuroda, Kazumi Koga, Sanae Kojima, Izumi Masamoto, Hiroki Masuda, Sumio Masunaga, Aimi Matsuoka, Haruka Matsuo, Takuya Matsuoka, Yugo Matsukuma, Yu Matsushita, Chihiro Matsushima, Masato Matsubayashi, Mayu Matsumura, Kaori Matsumoto, Tamami Matsumoto, Chiharu Maruta, Yuji Maruyama, Kazuhiro Miura, Daisuke Miura, Hirofumi Miura, Masahiro Mizukami, Masami Mitsunaga, Mitsuhiro Mine, Naoki Minoda, Yasuhiro Miyazaki, Harumi Miyazawa, Ryoko Miyanohara, Ayumi Miyamoto, Mitsuaki Muta, Kenta Mutou, Etsuko Muranaka, Yasuto Murohara, Tomoko Motosu, Hiroshi Momota, Takayuki Mori, Mayumi Morishita, Shinji Morimoto, Hiroko Nakao, Yukino Nakasako, Kaori Nakashima, Koji Nakashima, Tetsuya Nakashima, Harunobu Nakashima, Yukimi Nakamura, Akiko Nakano, Akiko Nakano, Keisuke Nagano, Kota Nakamura, Yohei Nakayama, Miho Nishiura, Yuji Nishikata, Yoshikazu Nishida, Akiko Nishiyori, Kiku Nonaka, Yuki Okubo, Tamami Osaka, Miki Otani, Kie Onishi, Hidenori Onishi, Mikiko Oohara, Yoshikazu Omae, Keiko Omachi, Yumi Okazaki, Kazuhito Ogata, Yuji Ogata, Yukari Ogata, Yuri Ogata, Hiroshi Okabe, Chiho Ogawa, Shigeki Oda, Akihiro Onizuka, Michio Ono, Nao Onodera, Daiki Oyama, Noriko Saito, Yoshiharu Saito, Tsukasa Sakaguchi, Yuko Sakami, Mitsuru Sakita, Yasuo Sasaki, Keiko Sasada, Naomi Sato, Yuki Sato, Ayaka Sameshima, Sumika Sawada, Hiromichi Shiotsu, Hirofumi Shigaki, Chiemi Shigyou, Naomi Shibata, Mutsumi Shimasaki, Toshihiko Shimada, Ayumi Shimokama, Kimiyo Shinyashiki, Sumika Sugahara, Aya Sugita, Iwao Takiguchi, Yasumitsu Takeuchi, Emiko Takeda, Kyoko Takemoto, Hiroki Tajiri, Shinji Tanaka, Rika Tanaka, Keiji Tanoue, Megumi Tanoue, Keisuke Tabuchi, Kyoko Tsushida, Kaori Tsushima, Tsutomu Tsuda, Kazumi Tsuruta, Toshihiro Teshima, Takeshi Terajima, Yoshihiro Tomioka, Masatomo Tomizono, Ayako Tomita, Manao Toyoshima, Kouji Uesaka, Masafumi Ueda, Mayumi Ueno, Naomi Uehara, Yukishiro Uehara, Yoshie Ujikawa, Yuka Ushijima, Aki Ujihara, Soushi Uchida, Yoshio Uchida, Satoru Umihata, Toru Umihata, Yusuke Uramoto, Makiko Yahiro, Katsutoshi Yamaguchi, Keiko Yamaguchi, Junji Yamaguchi, Hiroo Yamaguchi, Taku Yamasaki, Keiichiro Yamamichi, Nobuhisa Yamamura, Kenji Yamamoto, Koji Yamamoto, Tami Yamamoto, Ryoji Yokote, Akiharu Yoshioka, Masatsugu Yoshiki. Shunsuke Yoshida, Momoko Yoshida, Tatsuya Yoshinouchi, Terutada Waki, Yurie Watanabe, and Hideaki Watanabe.

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