Hostname: page-component-848d4c4894-4hhp2 Total loading time: 0 Render date: 2024-06-02T14:12:17.944Z Has data issue: false hasContentIssue false

Can Live-Actor Patients in a Mass Casualty Incident Exercise Benefit as Exercise Players?

Published online by Cambridge University Press:  28 July 2023

Wei-Kuo Chou
Affiliation:
Department of Emergency Medicine, National Taiwan University Hospital, Taipei, Taiwan
Wen-Chu Chiang
Affiliation:
Department of Emergency Medicine, National Taiwan University Hospital Yunlin Branch, Yunlin, Taiwan
Ya-Wen Chen
Affiliation:
Department of Emergency Medicine, National Taiwan University Hospital Yunlin Branch, Yunlin, Taiwan
Ming-Tai Cheng*
Affiliation:
Department of Emergency Medicine, National Taiwan University Hospital Yunlin Branch, Yunlin, Taiwan
*
Corresponding author: Ming-Tai Cheng; Email: jengmt1976@gmail.com
Rights & Permissions [Opens in a new window]

Abstract

Objectives:

In a mass casualty incident (MCI) exercise, live-actor patients (LAPs) simulated different scenarios in the exercise. This study compared the benefit to LAPs with that to exercise players (EPs) and nonparticipants (NPs).

Methods:

An MCI exercise was conducted in 2018. Emergency department (ED) nurses were assigned as EPs, LAPs, or NPs and asked to attend a pre-exercise lecture. A pre-exercise survey evaluated all ED nurses’ background, confidence level, and knowledge of MCI management. Knowledge assessment included disaster medicine knowledge (DMK) and on emergency operation plan familiarity (EOPF). The same survey was conducted again after the exercise. A paired t-test was used to analyze the difference before and after the exercise in the 3 groups.

Results:

Twenty-nine ED nurses completed both surveys. Confidence improved significantly for both the EP and LAP groups. The DMK of the LAP group improved significantly. EOPF also improved significantly for all 3 groups. A comparison of the improvement levels showed no significant difference between the EP and LAP groups for confidence, DMK, and EOPF.

Conclusions:

ED nurses can benefit from participating as LAPs in full-scale MCI exercises. Having ED nurses act as LAPs makes it possible to train more staff in 1 exercise.

Type
Original Research
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.
Copyright
© The Author(s), 2023. Published by Cambridge University Press on behalf of the Society for Disaster Medicine and Public Health

A mass casualty incident (MCI) is a major threat to the hospital and emergency department (ED). Thus, to simulate an MCI, the exercise requires an adequate number of patients. These mock patients may be simulated by mannequins or live actors, each with different advantages. Reference Gillett, Peckler and Sinert1,Reference Schulz, Skrzypczak and Raith2 The MCI simulation with live-actor patients (LAPs) has been used for over 50 years. Reference Ingrassia, Pigozzi and Bono3 Some exercises have used laypeople or students as LAPs, while other exercises have used trained actors. Reference Schulz, Skrzypczak and Raith2,Reference Gist, Daniel and Grock4,Reference Emery, Sprau and Morecook5 Actors with a medical background have also been used as LAPs in some exercises, Reference Scott, Maddux and Schnellmann6 while in other training exercises, trainees have been used as LAPs. Reference Kose, Unver and Tastan7Reference Jones, Staub and Seymore9

In hospital MCI exercises in Taiwan, hospital staff are commonly used as LAPs to reduce exercise costs. Because experience-based learning is an important component of disaster exercises, the experience of participating in an MCI exercise as an LAP may offer trainees another way of learning. Reference Kose, Unver and Tastan7 A previous study also revealed that acting as a standardized patient had educational value for medical students in clinical skills courses. Reference Mavis, Ogle and Lovell10 If an LAP can benefit as much as an exercise player (EP), we can train more hospital staff in 1 MCI exercise. This can make MCI exercises more effective tools for training purposes. However, no previous quantitative study has evaluated the exercise outcomes for LAPs. Therefore, this study compares the benefits of LAPs with those of EPs and nonparticipants (NPs).

Methods

MCI Exercise Design

A hospital MCI exercise was conducted in 2018. The scenario of this exercise was a major traffic accident resulting in 30 trauma patients being sent to the ED. The purposes of this exercise were to evaluate the hospital emergency operation plan (EOP) and to train hospital staff. This was a full-scale exercise that involved ED nurses and other hospital staff, including physicians, security guards, and administrative staff. The physicians, security guards, and administrative staff were all EPs, but ED nurses were assigned to 4 different roles based on their shifts, the supervisor’s decision, and exercise needs. The ED nurses were assigned roles of EP, controller, facilitator, and LAP.

Nurses who were assigned the EP role were asked to be ED nurses in the exercise. Controllers were asked to manage the exercise, and facilitators assisted in the conduct of the exercise. LAPs were asked to present their symptoms and signs of injuries and had moulage applied to simulate wounds, blood, and dressings. They were also asked to observe the EPs’ operations and give feedback during the post-exercise debriefing.

The exercise was conducted in the emergency room. ED nurses who did not participate in the MCI exercise were responsible for managing the actual ED patients. All ED nurses were asked to attend a lecture before the MCI exercise. The lecture contained information regarding the Hospital Incident Command System (HICS) and the Simple Triage and Rapid Treatment (START) algorithm. The Eps used the HICS and START triage methods in the MCI exercise.

LAPs were given instructions before the MCI exercise to increase the simulation fidelity. The exercise management team leader explained each role in the exercise, provided information about the simulation preparations and gave a short lecture to enable the LAPs to simulate the symptoms and signs of patients in an MCI. The exercise controller explained the purpose of the simulated injuries in the MCI exercise and answered the LAPs’ questions.

During the exercise, the EPs needed to take histories and perform physical examinations on the LAPs. The physicians of EPs could also arrange tests and provide treatment for LAPs in a safe way. LAPs could be discharged home or physically sent to the ward, intensive care unit, or operation room without entering it. In addition to presenting the symptoms and signs, LAPs also need to observe and informally evaluate the performance of EPs.

Study Design

ED nurses who were assigned to be EPs were defined as the EP group. ED nurses who played the role of MCI victims were defined as the LAP group. ED nurses who were not involved in the exercise were defined as the NP group. The pre-exercise survey was explained by the exercise management team leader and conducted with all ED nurses before the day of the exercise. The survey was used to evaluate the baseline MCI preparedness status of ED nurses, which included an informed consent section, demographic questionnaire, confidence level toward MCI management assessment, and knowledge assessment. The exercise management team leader collected the data. The demographic questionnaire included age, gender, working years, and previous disaster training experience (PDTE). PDTE was defined as the number of training sessions that ED nurses had completed before this MCI exercise.

The confidence level toward MCI management was self-assessed by all ED nurses using a 5-point Likert scale, where 1 = very unconfident and 5 = very confident. The knowledge assessment had 2 parts: disaster medicine knowledge (DMK) and emergency operation plan familiarity (EOPF). Each part included 10 multiple-choice questions. The correct answer was given 10 points, whereas the incorrect answer received 0 points.

The tests were designed and validity was assessed by experts in emergency and disaster medicine. The internal consistency and reliability of these 2 tests were assessed by a pilot sample of 37 nurses before the exercise, and Cronbach’s alphas were 0.77 and 0.82 for the DMK and EOPF tests, respectively.

A debriefing was conducted immediately after the MCI exercise. Exercise evaluators discussed the strengths and areas for improvement with EPs, and the LAPs also shared their observations and opinions. A postexercise survey was conducted after the debriefing to evaluate training effectiveness. The postexercise survey was conducted with the same ED nurses, with the same content as the pre-exercise survey. The results collection was the same as the pre-exercise survey. ED nurses who completed both the pre- and postexercise surveys were included in the study.

Analysis

A paired t-test was used to analyze the differences in the mean scores of the 3 groups (EP, LAP, and NP) before and after the exercise. The measured data were described as mean ± standard deviation. An analysis of variance (ANOVA) and Fisher’s least significant difference (LSD) were used to compare the levels of improvement among each group. A P-value of less than 0.05 was defined as statistically significant. Data were analyzed using SPSS 20.0 software (IBM Corp., Armonk, NY).

Results

Among the 49 ED nurses, 29 completed both the pre- and postexercise surveys and were included in the study. The EP group included 10 ED nurses, 9 of whom completed both surveys. The LAP group included 20 ED nurses, 11 of whom completed both surveys. The NP group included 19 ED nurses, 9 of whom completed both surveys. Table 1 shows the demographic characteristics of the 3 groups. None of the participants had actual experience in MCI management.

Table 1. Demographic characteristics of the 3 groups

Note: Abbreviations: EP, exercise player; LAP, live-actor patient; NP, nonparticipant; PDTE, previous disaster training experience; y/o, year old; yr, year.

The scores of the pre- and postexercise confidence levels for MCI management and knowledge assessments are detailed in Figure 1. After the exercise, the confidence level toward MCI management increased significantly in both the EP and LAP groups (2.8 to 3.8 and 2.9 to 4.3, respectively). The confidence level in the NP group showed no significant change (3.3 to 3.7). Analysis of variance (ANOVA) showed a significant difference among the groups (P = 0.003). Fisher’s LSD showed a significant difference in the confidence level increase between the LAP and NP groups (P = 0.009).

Figure 1. The scores of the pre- and postexercise confidence levels for MCI management and knowledge assessments. DMK, disaster medicine knowledge; EOPF, emergency operation plan familiarity.

The DMK scores of the LAP group improved significantly after the exercise (43.6-62.7; P = 0.012). The DMK scores of the EP group showed improvement without statistical significance (46.4-61.1; P = 0.117). The DMK score of the NP group showed a slight decrease (43.3-42.2) without statistical significance. ANOVA showed a significant difference among the groups (P = 0.008). Fisher’s LSD showed a significant difference between the LAP and NP groups (P = 0.002).

The EOPF scores of all 3 groups improved significantly after the exercise (EP group: 36.6 to 58.8; P = 0.003; LAP group: 33.6 to 55.4; P = 0.01; NP group: 22.2 to 45.5; P = 0.01). ANOVA showed no significant difference among the groups (P = 0.9).

Discussion

Because disasters are events that occur suddenly and violently, it is imperative to prepare hospital staff to respond. Reference Ingrassia, Pigozzi and Bono3 As proxies for actual disasters, exercises can offer hospital staff effective training and an opportunity to practice. Reference Hsu, Jenckes and Catlett11Reference Wallace, Gillett and Wright13 However, designing and conducting such full-scale MCI exercises require significant time and resources. Reference Gillett, Peckler and Sinert1,Reference Olsén, Hallberg and Mattsson14 Additionally, the number of EPs is usually limited in the exercise. To gain the most out of these exercises, 1 possibility is to create a greater learning effect from the exercises for participants other than EPs. Reference Olsén, Hallberg and Mattsson14 As the first quantitative research study regarding the benefits of participating as an LAP in a disaster exercise, this study indicated that acting as an LAP is effective for improving staff confidence and knowledge. Therefore, being an LAP in the exercise could provide an additional training method for hospital staff in the future. The lack of staff involvement in hospital disaster preparedness is a worldwide problem. Reference Bartley, Stella and Walsh15 Our results indicated that being an LAP may solve this problem. Moreover, disasters do not occur frequently, and repeated training is necessary to maintain hospital staffs’ ability to respond to disasters. Reference Summerhill, Mathew and Stipho16 However, the repeated experience of being an EP may increase staff workload. Based on these study results, hospital staff can also benefit from being LAPs to increase the effectiveness of the training exercises.

The management of an MCI requires confidence and knowledge. However, previous research and our results indicated that hospital staff lack confidence in MCI management, Reference Madge, Kersey and Murray17 which may be due to a lack of training or MCI exercises. Reference Madge, Kersey and Murray17 Previous studies have indicated that the confidence of disaster exercise players increased after exercise participation. Reference Summerhill, Mathew and Stipho16,Reference Sena, Forde and Yu18,Reference Skryabina, Reedy and Amlȏt19 Our results revealed that the level of confidence increased after the MCI exercise only for the EP and LAP groups. This result indicated that exercise participation, regardless of whether it is as a player or mock patient, can increase confidence. LAPs can become more confident by analyzing disaster management through, for example, being triaged and treated as mock patients Reference van Soeren, Devlin-Cop and Macmillan20

In addition to confidence, hospital staff need adequate knowledge of disaster medicine and familiarity with the EOP to manage an MCI successfully. Our pre-exercise survey revealed a low score for DMK and EOPF for all 3 groups, which may indicate insufficient staff training, supporting the findings of another study. Reference Madge, Kersey and Murray17 Some studies have also pointed out the poor knowledge levels of hospital disaster plans and response protocols among hospital staff. Reference Bartley, Stella and Walsh15,Reference Skryabina, Reedy and Amlȏt19 However, disaster exercises and pre-exercise preparation as educational opportunities can improve preparedness. Reference Bartley, Stella and Walsh15,Reference Skryabina, Reedy and Amlȏt19 Our results also indicated that the LAPs’ DMK improved significantly after the MCI exercise.

The principles of adult learning may explain this finding. The first assumption of adult learning is that participants need to know why they are learning. Reference Winskog, Tonkin and Byard21 In an MCI exercise, LAPs need to present clinical symptoms and signs to EPs. More importantly, LAPs need to understand the meaning of their role and why it is important in MCI exercises. Reference Bryan, Kreuter and Brownson22 This need gives LAPs a reason for learning. The authentic nature of the MCI simulation differs from the passive reception of knowledge through a lecture, and the role of an LAP offers nurses a motivation to acquire knowledge actively. The MCI exercise thus provided an opportunity for these learners to reflect upon the material being learned and practice their knowledge in the exercise. Reference Kose, Unver and Tastan7,Reference van Soeren, Devlin-Cop and Macmillan20,Reference Winskog, Tonkin and Byard21 This may also suggest the importance of the motivation created by participation in the exercise.

Olsén et al. compared the learning effects of EPs and observers and found that both players and observers could learn from exercises. Reference Olsén, Hallberg and Mattsson14 In that study, the authors pointed out that EPs learn through experience and observers learn from an overview perspective. Reference Olsén, Hallberg and Mattsson14 Like exercise observers, LAPs can observe what EPs are doing during the exercise. Through observation, LAPs can learn from finding errors in aspects of the care that they receive and the disaster response of EPs. Reference Gist, Daniel and Grock4 Moreover, they can gain new insights when relating the performance of EPs to how they would have acted. Reference Olsén, Hallberg and Mattsson14 However, observers may perceive a decrease in the realism of the exercise due to a lack of participation. Reference Harder, Ross and Paul23 In contrast to observers, LAPs can observe EPs while participating in an exercise. Therefore, LAPs may learn from the aspects of being both a player and an observer.

To participate in the disaster exercise, EPs need to review the EOP before the exercise. On the other hand, the nature of using LAPs in the exercise to test the disaster plan may motivate LAPs to review the EOP. Although the EOPF scores increased in all 3 groups in our results, the pre- and post-exercise scores of the NP group were lower than the scores of the other 2 groups. It can be assumed that MCI exercises can promote EOP reading and increase familiarity with the EOP for both participants and nonparticipants, but the effectiveness can be increased while participating in the exercise, regardless of the role.

Our pre-exercise survey was conducted after the role assignment. The assignment may provide motivation for learning to LAPs and NPs, because they need to know about disaster medicine and EOP. Due to the need to participate in the exercise, LAPs and NPs might feel less confident and try to read EOP and learn some disaster medicine before the exercise. This may explain the pre-exercise survey results. In addition, the role assignment and exercise participation may also cause LAPs and NPs to learn from the exercise. This may lead to the difference after the exercise.

In addition to the exercise itself, pre-exercise preparation programs are also important for LAPs to learn. In some cases, the programs include lectures or briefings for all exercise participants, including EPs and LAPs. The pre-exercise activity may contribute to learning by addressing the importance and relevance of the issues that learners must address during the exercise. Reference Skryabina, Reedy and Amlȏt19 In addition, LAPs are trained before the exercise by experts in emergency and disaster medicine to portray disaster patients. Reference Ingrassia, Pigozzi and Bono3 This pre-exercise training for LAPs may become another interactive format with specific educational goals. Reference Mavis, Ogle and Lovell10 Furthermore, a postexercise debriefing offers participants an opportunity to discuss what happened during the exercise and identify what lessons could be learnt from it. By participating in the debriefing, LAPs may reflect on what happened during the exercise, which may transform their experience into learning. Reference Olsén, Hallberg and Mattsson14 As LAPs in the current study participated in the pre-exercise lecture and post-exercise debriefing, this may explain the significant improvement in their knowledge and EOPF after the MCI exercise.

Limitations

This study has several limitations. The first limitation was the study participants. The group assignment was not random, and the demographic distribution of the 3 groups was different, which may have caused some degree of selection bias. Because the MCI exercise was held by the ED, all participants were from the same department and the number of participants was limited. The response rates of the LAP and NP groups were not high, which may have also influenced the results.

Second, the participants’ subjective feelings about learning during the exercise were not evaluated. There was no evaluation of the possible factors that could have increased their confidence level in MCI management or improved their knowledge, which may have interfered with the analysis of learning effectiveness.

Third, we investigated only the effects of the MCI exercise. Disaster exercises are conducted in hospitals with different disasters, such as earthquakes or fires. Although disasters other than MCI may create many patients, our study only analyzed the effect of the MCI exercise. The learning effect of LAPs in exercises other than an MCI remains uncertain.

Finally, the LAPs in our study were asked to observe the EPs’ operations informally. LAPs can be used to collect data during a disaster exercise and can even contribute to the exercise evaluation and after-action review. Reference Ingrassia, Carenzo and Barra24 If LAPs in an MCI exercise are asked to do more evaluation work, they might have more chances to learn and improve their knowledge.

Conclusions

In summary, participating as an LAP in an MCI exercise can increase confidence in MCI management and familiarity with hospital EOP as much as participating as an EP. Participating as an LAP can also improve knowledge of disaster medicine better than participating as an EP. More hospital staff can be trained during an MCI exercise by acting as an LAP.

Supplementary material

The supplementary material for this article can be found at https://doi.org/10.1017/dmp.2023.97.

Acknowledgments

We thank the NTUH Yunlin Branch ED nurses for their support of the research and their ongoing dedication to emergency care.

Author contribution

W.K.C. drafted and revised the manuscript. M.T.C. and W.C.C. revised and edited the manuscript. W.K.C. and M.T.C. conceived the study design. Y.W.C. undertook recruitment of participants and collected the data. W.K.C. and W.C.C. supervised the conduct of study and data collection. All authors contributed substantially to its revision. M.T.C. takes responsibility for the study.

Competing interests

The authors have no conflicts of interest to disclose.

Funding

None.

Ethical standard

The study protocol was approved by the institutional review board of the National Taiwan University Hospital (201905098RIND). Informed consent was obtained from all subjects before enrollment. To protect the privacy of the participants, all surveys were filled out anonymously and the researchers kept all data confidential.

References

Gillett, B, Peckler, B, Sinert, R, et al. Simulation in a disaster drill: comparison of high-fidelity simulators versus trained actors. Acad Emerg Med. 2008;15(11):1144-1151.CrossRefGoogle Scholar
Schulz, CM, Skrzypczak, M, Raith, S, et al. High-fidelity human patient simulators compared with human actors in an unannounced mass-casualty exercise. Prehosp Disaster Med. 2014;29(2):176-182.CrossRefGoogle Scholar
Ingrassia, PL, Pigozzi, L, Bono, M, et al. Use of simulated patients in disaster medicine training: a systematic review. Disaster Med Public Health Prep. 2021;15(1):99-104.CrossRefGoogle ScholarPubMed
Gist, R, Daniel, P, Grock, A, et al. Use of medical reserve corps volunteers in a hospital-based disaster exercise. Prehosp Disaster Med. 2016;31(3):259-262.CrossRefGoogle Scholar
Emery, RJ, Sprau, DD, Morecook, RC, et al. Surge capacity volunteer perspectives on a field training exercise specifically designed to emphasize likely roles during a disaster response. Health Phys. 2009;97(5 Suppl):S155-S160.CrossRefGoogle ScholarPubMed
Scott, LA, Maddux, PT, Schnellmann, J, et al. High-fidelity multiactor emergency preparedness training for patient care providers. Am J Disaster Med. 2012;7(3):175-188.CrossRefGoogle ScholarPubMed
Kose, G, Unver, V, Tastan, S, et al. Embedded participants in simulation-based disaster education: experiences of nursing students. Clin Simul Nurs. 2020;47:9-15.CrossRefGoogle Scholar
Scott, LA, Madden, LA, Wahlquist, AE, et al. Preparing for the surge: a half-day emergency preparedness training course for the “Second Front”. Disaster Med Public Health Prep. 2018;12(1):121-126.CrossRefGoogle ScholarPubMed
Jones, J, Staub, J, Seymore, A, et al. Securing the second front: achieving first receiver safety and security through competency-based tools. Prehosp Disaster Med. 2014;29(6):643-647.CrossRefGoogle ScholarPubMed
Mavis, BE, Ogle, KS, Lovell, KL, et al. Medical students as standardized patients to assess interviewing skills for pain evaluation. Med Educ. 2002;36(2):135-140.CrossRefGoogle ScholarPubMed
Hsu, EB, Jenckes, MW, Catlett, CL, et al. Effectiveness of hospital staff mass-casualty incident training methods: a systematic literature review. Prehosp Disaster Med. 2004;19(3):191-199.CrossRefGoogle ScholarPubMed
Savoia, E, Biddinger, PD, Burstein, J, et al. Inter-agency communication and operations capabilities during a hospital functional exercise: reliability and validity of a measurement tool. Prehosp Disaster Med. 2010;25(1):52-58.CrossRefGoogle ScholarPubMed
Wallace, D, Gillett, B, Wright, B, et al. Randomized controlled trial of high fidelity patient simulators compared to actor patients in a pandemic influenza drill scenario. Resuscitation. 2010;81(7):872-876.CrossRefGoogle Scholar
Olsén, M, Hallberg, N, Mattsson, KD. Who learns from crisis management exercises: an explorative study. Paper presented at the ISCRAM conference, Valencia, Spain, 2019.Google Scholar
Bartley, BH, Stella, JB, Walsh, LD. What a disaster?! Assessing utility of simulated disaster exercise and educational process for improving hospital preparedness. Prehosp Disaster Med. 2006;21(4):249-255.CrossRefGoogle ScholarPubMed
Summerhill, EM, Mathew, MC, Stipho, S, et al. A simulation-based biodefense and disaster preparedness curriculum for internal medicine residents. Med Teach. 2008;30(6):e145-e151.CrossRefGoogle ScholarPubMed
Madge, SN, Kersey, JP, Murray, G, et al. Are we training junior doctors to respond to major incidents? A survey of doctors in the Wessex region. Emerg Med J. 2004;21(5):577-579.CrossRefGoogle ScholarPubMed
Sena, A, Forde, F, Yu, C, et al. Disaster preparedness training for emergency medicine residents using a tabletop exercise. MedEdPORTAL. 2021;17:11119.CrossRefGoogle ScholarPubMed
Skryabina, E, Reedy, G, Amlȏt, R, et al. What is the value of health emergency preparedness exercises? A scoping review study. Int J Disaster Risk Reduct. 2017;21:274-283.CrossRefGoogle Scholar
van Soeren, M, Devlin-Cop, S, Macmillan, K, et al. Simulated interprofessional education: an analysis of teaching and learning processes. J Interprof Care. 2011;25(6):434-440.CrossRefGoogle ScholarPubMed
Winskog, C, Tonkin, A, Byard, RW. The educational value of Disaster Victim Identification (DVI) missions-transfer of knowledge. Forensic Sci Med Pathol. 2012;8(2):84-87.CrossRefGoogle ScholarPubMed
Bryan, RL, Kreuter, MW, Brownson, RC. Integrating adult learning principles into training for public health practice. Health Promot Pract. 2009;10(4):557-563.CrossRefGoogle ScholarPubMed
Harder, N, Ross, CJM, Paul, P. Student perspective of roles assignment in high-fidelity simulation: an ethnographic study. Clin Simul Nurs. 2013;9(9):e329-e334.CrossRefGoogle Scholar
Ingrassia, PL, Carenzo, L, Barra, FL, et al. Data collection in a live mass casualty incident simulation: automated RFID technology versus manually recorded system. Eur J Emerg Med. 2012;19(1):35-39.CrossRefGoogle Scholar
Figure 0

Table 1. Demographic characteristics of the 3 groups

Figure 1

Figure 1. The scores of the pre- and postexercise confidence levels for MCI management and knowledge assessments. DMK, disaster medicine knowledge; EOPF, emergency operation plan familiarity.

Supplementary material: File

Chou et al. supplementary material

Chou et al. supplementary material

Download Chou et al. supplementary material(File)
File 34.2 KB