The Impact of Concussion Education on Injury Disclosure in High School Athletes: A Critically Appraised Topic

in International Journal of Athletic Therapy and Training

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Alyson HansbargerTemple University

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Ryan ThomsonTemple University

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Jamie L. MansellTemple University

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Ryan T. TierneyTemple University

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Clinical Scenario: Sport-related concussions are common injuries during sport-related activities. Evaluations of these injuries involve symptom reporting. Unfortunately, concussion symptoms are widely underreported by athletes, and can lead to longer recovery times. Concussion education programs were created to encourage reporting of symptoms by athletes. Clinical Question: Does concussion education impact injury disclosure in high school athletes? Summary of Key Findings: Three studies were included in this appraisal. Two studies utilized an educational lecture, and one study utilized an informational video providing the concussion education. All three studies found significant increases in injury history disclosure from pre-education to immediate post-education. Clinical Bottom Line: There is moderate evidence to support the idea that education has a positive impact on concussion reporting behaviors. These studies found positive results immediately following concussion education therefore it may be beneficial to provide concussion education several times a year. Strength of Recommendation: There is Level B evidence to support the idea that implementing concussion education will impact concussion reporting behaviors as it pertains to injury history disclosure.

Key Points

  1. The delivery method, the contents, and the language included in concussion education can play a role in injury disclosure.
  2. The benefits of concussion education as it impacts concussion injury disclosure work in a short-term timeframe.
  3. There is moderate evidence to support that concussion education improves previous injury disclosure high school athletes.

Clinical Scenario

In the year 2017, 2.5 million high school athletes reported sustaining at least one activity- or sport-related concussion.1 Concussions are brain injuries caused by biomechanical forces applied to the head or body, resulting in clinically relevant signs or symptoms.2 The signs and symptoms of concussion are diverse, including changes in cognitive, vestibular, oculomotor function, and mood, which are evaluated to diagnose concussion injuries.2,3

Current evaluation protocols include symptom checklists, cognitive status examinations, motor control tests, vestibular, and oculomotor assessments.2,4 While these assessment tools are effective at identifying deficits, many go unnoticed due to a lack of symptom reporting by the athlete.5 Athletes may underreport their symptoms for many reasons including fear of losing playing time, underestimating the seriousness of the injury, not knowing if the injury was a concussion, not wanting to let their teammates or coach down, or not wanting to risk a future sports scholarship.5 Unfortunately, by continuing to play with these injuries, the athletes may be subject to prolonged recovery and more postconcussion symptoms.6 Current state concussion laws include mandatory concussion education in an attempt to mitigate underreporting and subsequent dangers.7

There are various presentation methods for concussion education, which include oral presentations, educational videos, and computer-based learning.812 These educational programs have been shown to increase concussion knowledge for both athletes and coaches from the youth sport level to the collegiate sport level.8,13,14 While these education programs increase concussion knowledge, they may not directly translate into increased symptom reporting.7,15 The few studies that have been published about the relationship between concussion knowledge and reporting have shown that the athletes have plenty of knowledge about what concussion symptoms are, but still were less likely to report symptoms to an authoritative figure.16 If concussion educational programs are not increasing reporting behaviors, the current programs and guidelines may need to be revisited to improve their impact on reporting behaviors. Therefore, the purpose of this appraisal was to evaluate the connection between concussion education and reporting behavior as it pertains to injury disclosure in high school athletes.

Focused Clinical Question

Does concussion education impact injury disclosure in high school athletes?

Search Strategy

A comprehensive search of PubMed and SPORTDiscus databases was conducted in January of 2020 using a Population/Intervention/Outcome strategy. The terms “concussion education,” “concussion knowledge,” and “concussion information” were individually searched in combination with “reporting behaviors.”

  1. Patient: high school student athletes.
  2. Intervention: concussion education.
  3. Outcome: concussion injury disclosure.

Inclusion Criteria

The following were identified for inclusion:

  1. Included high school population.
  2. Studies that utilized concussion education intervention.
  3. Studies that measured outcome through a participant survey.
  4. Included injury disclosure immediately following the intervention as an outcome.
  5. Peer-reviewed studies published in English.
  6. Level of evidence 3 or higher.

Exclusion Criteria

  1. Studies published prior to 2010.
  2. Critically appraised topics and systematic reviews.
  3. Included athletes in middle school or younger, or collegiate-level athletes.

Evidence Quality Assessment

All three studies included in this analysis were assessed using the STROBE checklist. Two10,11 studies were analyzed using the STROBE assessment for cross-sectional studies, and one study9 was analyzed using the STROBE combination (i.e., cross-sectional and cohort) assessment. Assessment by the authors found STROBE scores in the range of 15–17. Results of the quality assessment can be found in Table 1.

Table 1

Characteristics of Included Studies

Miyashita et al.11Hunt9Miyashita et al.10
TitleGender differences in concussion reporting among high school athletesVideo educational intervention improves reporting of concussion and symptom recognitionHigh school athletes’ perceptions of concussion
Participants454 high school athletes (212 females and 242 males, 15.7 ± 1.15 years old)Convenience sample of 68 high school athletes (14.72 and 14.92 average age) in South Carolina454 (212 female and 242 male) high school athletes in one school district
Inclusion criteriaN/AAny gender, age 13–19, and participation in fall junior varsity and varsity athleticsN/A
Exclusion criteriaN/AEnglish as a second languageParticipants who played two sports only were included for the first sport
Educational componentEducation component: Lecture included baseline questions about current knowledge, mechanism of injury, signs/symptoms, long-term side effects, impact on education/learning, baseline testing, and RTP protocolsEducational component: A 9-min long concussion video was used and contained information regarding epidemiology, mechanism of injury, sports in which they occur, signs and symptoms, reasons not to report, where and when to report, and potential long-term effectsEducation component: Lecture included baseline questions about current knowledge, mechanism of injury, signs/symptoms, long-term side effects, impact on education/learning, baseline testing, and RTP protocols
Outcome measuresAssessment: Survey questions were answered using clickers before and after the educational lecture where the responses were anonymous and recorded. The survey included background information, previous medical history, personal perceptions, and questions about knowledge of concussionsAssessment: Questionnaire was created by combining previously used student-athlete surveys. Fourteen items and a symptom recognition list (maximum score of 17). Questions also assessed previous history of concussion, if they reported, to whom they reported, and reasons for not reportingAssessment: Survey questions were answered using clickers before and after the educational lecture where the responses were anonymous and recorded. The survey included background information, previous medical history, personal perceptions, and questions about knowledge of concussions
ResultsBoys were more likely not to report a concussion (p = .40), no significance between groups, but separately, girls reported more PMH concussions after educational intervention (p < .001) and males indicated that they had sustained a greater number of concussions following educational lecture (p < .001)Statistically significant difference in previous history of concussion before and after education in experimental group (p = .034), but not significant in control group. Following concussion education, there was a significant difference between the symptom recognition following (p = .008)Significant difference between self-reporting PMHx of concussion before and after education (p = .000). Majority of athletes felt that important of a game should influence RTP
Level of evidenceLevel 2bLevel 2bLevel 2b
STROBE score16/2217/2215/22
Support for the answerYesYesYes

Abbreviations: RTP, return to play; PMH, past medical history; STROBE, strengthening the reporting of observational studies in epidemiology; PMHx, Past medical history.

Results of Search: Summary of Search, “Best Evidence” Appraised, and Key Findings

A summary of search results can be found in Supplementary Figure 1 (available online). Miyashita et al.11 utilized an anonymous survey to assess personal medical history, which revealed a significantly higher number of concussions reported by athletes immediately following an educational lecture. The same educational lecture and survey was used by Miyashita et al in 201611 but focused on the likelihood of reporting a concussion and found that females were more likely to report a concussion after receiving the education. Hunt9 used a similar survey that included concussion incidence and symptoms before and after an intervention, but also included a control group who received a nutrition lecture instead of a concussion education lecture. There was a statistically significant increase in previous concussions after the intervention in the concussion education group.

Results of Evidence Quality Assessment

The articles were independently appraised by two researchers (A. Hansbarger and R. Thomson) and the scores were averaged. The cross-sectional studies by Hunt9 and Miyashita et al.10 had scores of 17/22 and 15/22, respectively. The cross-sectional cohort study by Miyashita et al.11 obtained a score of 16/22. Based on the Center for Evidence-Based Medicine: Levels of Evidence guidelines,17 each article had a level of evidence of 2b.

Almost all of the studies also implemented this intervention on a large sample of many different sports. All of the studies included an educational intervention that is feasible from a clinical application standpoint, while still obtaining data to show that injury disclosure increased following the intervention. Unfortunately, there was no standardized education intervention, therefore directly comparing the outcomes is not possible.

Clinical Bottom Line

There is moderate evidence to support the idea that concussion education has a positive impact on concussion reporting behaviors as it pertains to injury disclosure. All of the studies included saw increases in the number of past concussions reported pre- to postintervention. The interventions included in the studies were described thoroughly and are succinct enough to keep the attention of student athletes while getting the important information across. While concussion education is mandatory in most states, these studies provide templates and information on an effective concussion education intervention. While these interventions were successful immediately following the education, there is not enough evidence to show that the increase in injury disclosure will last over a longer period of time. Based on the results of these studies, it may be beneficial to include the education intervention at the beginning of each sport season to encourage information retention.

Strength of Recommendation

Although the studies included had consistent findings that demonstrated concussion education having an effect on concussion personal medical history disclosure, all three studies were of cohort and/or cross-sectional design.911 According to the Strength of Recommendation Taxonomy Scale, there is Level B evidence to support the idea that implementing concussion education will impact concussion reporting behaviors as it pertains to injury history disclosure.

Implications for Practice, Education, and Future Research

The purpose of this critically appraised topic was to determine whether concussion education programs influence reporting behaviors as they pertain to injury disclosure. The main outcome of reporting behaviors for this critically appraised topic came from the past concussion injury disclosure following concussion education. All of the studies utilized questionnaires to measure the outcomes by including questions about symptom recognition, demographic information, previous concussion history, and reporting questions.911 All of the three articles saw differences in their outcomes immediately following the implementation of a concussion education program. The highest magnitude of change in injury disclosure behaviors were seen immediately following the education intervention and slowly declined over time. In order to reap the benefits of concussion education and its influences in injury disclosure, it may be beneficial to provide the educational programing before and after each season to keep the information fresh in the athlete’s minds. It could also help to post infographics in areas frequented by athletes about the definition of a concussion or common signs and symptoms to act as reminders throughout the sport seasons.

While most of the questionnaires utilized to obtain outcomes in the studies were similar, the delivery of the concussion education differed slightly. The Miyashita studies10,11 where the educational lecture took about 25 min to complete and included topics such as mechanism of injury, signs/symptoms, long-term side effects, impact on education/learning, baseline testing, and return-to-play protocols. The Hunt study utilized an educational video instead of a slideshow or lecture. The video was shorter, lasting only 9 min, but contained the same information as the previous three studies. Other studies have previously noted using an interactive computer module or a computer game to convey the concussion education information.17,18 These two studies saw improvements in concussion knowledge, misconceptions, symptoms, and intention to take appropriate actions.17,18 While these tools may also be an effective option as a delivery method, it may not be beneficial for all age groups. Goodman et al.17 found that the computer game method lost the interest of 60% of participants over the age of 15, but held the interest of 90% of participants between the ages of 11 and 12. All of the education programs appeared to be effective and reach the goal of increasing knowledge and reporting behaviors in high school athletes; therefore, there is no definitive answer for which method is the best. Although there are plenty of options for information delivery, it is important to keep the target audience in mind both in how the educational content is being presented as well as what information is being presented.

The various types of educational programs were beneficial mostly due to the actual content provided within the intervention. By providing athletes with the appropriate definition of a concussion that can be understood by the adolescent population, the more previous concussive injuries may be recalled.10 This could also include using the proper terminology and encouraging athletes to recognize the term concussion rather than having their “bell rung.” Miyashita et al.11 also found that more athletes reported having their “bell rung” than those who reported a past medical history of a concussion injury. By applying the appropriate language and providing knowledge regarding signs and symptoms of a concussion, reporting behaviors are more likely to be influenced.10,11

In conclusion, there is evidence that concussion education programs increase the concussion injury disclosure of high school athletes immediately after receiving the programs. However, it is unknown if those effects are sustained throughout the duration of a season. Future research should identify the dissipation of concussion and positive attitudes throughout the duration of a season. Other research should identify the most effective content, as well as presentation format (i.e., video, lecture) and duration. Regardless of presentation methods, concussion education has shown to be effective at increasing knowledge and attitudes and should be administered to athletes prior to sport participation.

CAT Kill Date: May 2024

CATs have limited life and should be revisited approximately 2 years after publication (see https://doi.org/10.1123/ijatt.2020-0047).

References

  • 1.

    DePadilla L, Miller GF, Jones SE, et al. Self-reported concussions from playing a sport or being physically active among high school students—United States, 2017. MMWR Morb Mortal Wkly Rep. 2018;67(24):682685. PubMed ID: 29927909 doi:10.15585/mmwr.mm6724a3

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2.

    McCrory P, Meeuwisse W, Dvořák J, et al. Consensus statement on concussion in sport-the 5th international conference on concussion in sport held in Berlin, October 2016. Br J Sports Med. 2017;51(11):838847. PubMed ID: 28446457

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3.

    Mullally WJ. Concussion. Am J Med. 2017;130(8):885892. PubMed ID: 28502817 doi:10.1016/j.amjmed.2017.04.016

  • 4.

    Broglio SP, Cantu RC, Gioia GA, et al. National athletic trainers’ association position statement: management of sport concussion. J Athl Train. 2014;49(2):245265. PubMed ID: 24601910 doi:10.4085/1062-6050-49.1.07

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Kroshus E, Garnett B, Hawrilenko M, Baugh CM, Calzo JP. Concussion under-reporting and pressure from coaches, teammates, fans, and parents. Soc Sci Med. 2015;134(1):66. doi:10.1016/j.socscimed.2015.04.011

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 6.

    Fehily B, Fitzgerald M. Repeated mild traumatic brain injury: potential mechanism of damage. Trauma Brain Inj. 2017;26(7):11311155.

  • 7.

    Wallace J, Covassin T, Beidler E. Sex differences in high school athletes’ knowledge of sport-related concussion symptoms and reporting behaviors. J Athl Train. 2017;52(7):682688. PubMed ID: 28561626 doi:10.4085/1062-6050-52.3.06

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8.

    Caron JG, Bloom GA, Falcão WR, Sweet SN. An examination of concussion education programmes: a scoping review methodology. Inj Prev. 2015;21(5):301308. PubMed ID: 25825353 doi:10.1136/injuryprev-2014-041479

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 9.

    Hunt TN. Video educational intervention improves reporting of concussion and symptom recognition. Athl Train Educ J. 2015;10(1):6574. doi:10.4085/100165

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 10.

    Miyashita TL, Diakogeorgiou E, Hellstrom B, Kuchwara N, Tafoya E, Young L. High school athletes’ perceptions of concussion. Orthop J Sports Med. 2014;2(11):2325967114554549. doi:10.1177/2325967114554549

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11.

    Miyashita TL, Diakogeorgiou E, VanderVegt C. Gender differences in concussion reporting among high school athletes. Sports Health. 2016;8(4):359363. PubMed ID: 27233957 doi:10.1177/1941738116651856

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 12.

    Ebell MH, Siwek J, Weiss BD, et al. Strength of recommendation taxonomy (SORT): a patient-centered approach to grading evidence in the medical literature. Am Fam Physician. 2004;69(3):548556. PubMed ID: 14971837

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 13.

    Donnell Z, Hoffman R, Sarmiento K, Hays C. Concussion attitudes, behaviors, and education among youth ages 12–17: results from the 2014 YouthStyles survey. J Saf Res. 2018;64(1):163169. doi:10.1016/j.jsr.2017.12.001

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14.

    Carroll-Alfano M. Mandated high school concussion education and collegiate athletes’ understanding of concussion. J Athl Train. 2017;52(7):689. PubMed ID: 28535096 doi:10.4085/1062-6050-52.3.08

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 15.

    Register-Mihalik J, Linnan LA, Marshall SW, McLeod TCV, Mueller FO, Guskiewicz KM. Using theory to understand high school aged athletes’ intentions to report sport-related concussion: implications for concussion education initiatives. Brain Inj. 2013;27(7–8):878886. PubMed ID: 23789865 doi:10.3109/02699052.2013.775508

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16.

    Eagles ME, Bradbury-Squires DJ, Powell MF, Murphy JR, Campbell GD, Maroun FB. The impact of a concussion-U educational program on knowledge of and attitudes about concussion. Can J Neurol Sci. 2016;43(5):659664. PubMed ID: 27464985 doi:10.1017/cjn.2016.263

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17.

    Goodman D, Bradley NL, Paras B, et al. Video gaming promotes concussion knowledge acquisition in youth hockey players. J Adolesc. 2006;29(3):351360. PubMed ID: 16169584 doi:10.1016/j.adolescence.2005.07.004

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 18.

    Glang A, Koester MC, Beaver SV, et al. Online training in sports concussion for youth sports coaches. Int J Sports Sci Coach. 2010;5(1):111. PubMed ID: 20640175 doi:10.1260/1747-9541.5.1.1

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation

Hansbarger and Thomson are with the Department of Kinesiology, Temple University, Philadelphia, PA, USA. Mansell and Tierney are with the Department of Health and Rehabilitation Sciences, Temple University, Philadelphia, PA, USA.

Hansbarger (alysonhansbarger@gmail.com) is corresponding author.

Supplementary Materials

  • Collapse
  • Expand
  • 1.

    DePadilla L, Miller GF, Jones SE, et al. Self-reported concussions from playing a sport or being physically active among high school students—United States, 2017. MMWR Morb Mortal Wkly Rep. 2018;67(24):682685. PubMed ID: 29927909 doi:10.15585/mmwr.mm6724a3

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2.

    McCrory P, Meeuwisse W, Dvořák J, et al. Consensus statement on concussion in sport-the 5th international conference on concussion in sport held in Berlin, October 2016. Br J Sports Med. 2017;51(11):838847. PubMed ID: 28446457

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3.

    Mullally WJ. Concussion. Am J Med. 2017;130(8):885892. PubMed ID: 28502817 doi:10.1016/j.amjmed.2017.04.016

  • 4.

    Broglio SP, Cantu RC, Gioia GA, et al. National athletic trainers’ association position statement: management of sport concussion. J Athl Train. 2014;49(2):245265. PubMed ID: 24601910 doi:10.4085/1062-6050-49.1.07

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Kroshus E, Garnett B, Hawrilenko M, Baugh CM, Calzo JP. Concussion under-reporting and pressure from coaches, teammates, fans, and parents. Soc Sci Med. 2015;134(1):66. doi:10.1016/j.socscimed.2015.04.011

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 6.

    Fehily B, Fitzgerald M. Repeated mild traumatic brain injury: potential mechanism of damage. Trauma Brain Inj. 2017;26(7):11311155.

  • 7.

    Wallace J, Covassin T, Beidler E. Sex differences in high school athletes’ knowledge of sport-related concussion symptoms and reporting behaviors. J Athl Train. 2017;52(7):682688. PubMed ID: 28561626 doi:10.4085/1062-6050-52.3.06

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8.

    Caron JG, Bloom GA, Falcão WR, Sweet SN. An examination of concussion education programmes: a scoping review methodology. Inj Prev. 2015;21(5):301308. PubMed ID: 25825353 doi:10.1136/injuryprev-2014-041479

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 9.

    Hunt TN. Video educational intervention improves reporting of concussion and symptom recognition. Athl Train Educ J. 2015;10(1):6574. doi:10.4085/100165

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 10.

    Miyashita TL, Diakogeorgiou E, Hellstrom B, Kuchwara N, Tafoya E, Young L. High school athletes’ perceptions of concussion. Orthop J Sports Med. 2014;2(11):2325967114554549. doi:10.1177/2325967114554549

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11.

    Miyashita TL, Diakogeorgiou E, VanderVegt C. Gender differences in concussion reporting among high school athletes. Sports Health. 2016;8(4):359363. PubMed ID: 27233957 doi:10.1177/1941738116651856

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 12.

    Ebell MH, Siwek J, Weiss BD, et al. Strength of recommendation taxonomy (SORT): a patient-centered approach to grading evidence in the medical literature. Am Fam Physician. 2004;69(3):548556. PubMed ID: 14971837

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 13.

    Donnell Z, Hoffman R, Sarmiento K, Hays C. Concussion attitudes, behaviors, and education among youth ages 12–17: results from the 2014 YouthStyles survey. J Saf Res. 2018;64(1):163169. doi:10.1016/j.jsr.2017.12.001

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14.

    Carroll-Alfano M. Mandated high school concussion education and collegiate athletes’ understanding of concussion. J Athl Train. 2017;52(7):689. PubMed ID: 28535096 doi:10.4085/1062-6050-52.3.08

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 15.

    Register-Mihalik J, Linnan LA, Marshall SW, McLeod TCV, Mueller FO, Guskiewicz KM. Using theory to understand high school aged athletes’ intentions to report sport-related concussion: implications for concussion education initiatives. Brain Inj. 2013;27(7–8):878886. PubMed ID: 23789865 doi:10.3109/02699052.2013.775508

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16.

    Eagles ME, Bradbury-Squires DJ, Powell MF, Murphy JR, Campbell GD, Maroun FB. The impact of a concussion-U educational program on knowledge of and attitudes about concussion. Can J Neurol Sci. 2016;43(5):659664. PubMed ID: 27464985 doi:10.1017/cjn.2016.263

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17.

    Goodman D, Bradley NL, Paras B, et al. Video gaming promotes concussion knowledge acquisition in youth hockey players. J Adolesc. 2006;29(3):351360. PubMed ID: 16169584 doi:10.1016/j.adolescence.2005.07.004

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 18.

    Glang A, Koester MC, Beaver SV, et al. Online training in sports concussion for youth sports coaches. Int J Sports Sci Coach. 2010;5(1):111. PubMed ID: 20640175 doi:10.1260/1747-9541.5.1.1

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
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