The sensitivity and specificity of clinical measures of sport concussion:three tests are better than one

Editorial Review

The sensitivity and specificity of clinical measures of sport concussion:three tests are better than one

Jacob E Resch, Cathleen N Brown, Julianne Schmidt, Stephen N Macciocchi, Damond Blueitt, C Munro Cullum, Michael S Ferrara

BMJ Open Sport Exerc Med 2016;2:e000012. doi:10.1136/bmjsem-2015-000012

JACO Editorial Reviewer: Donald S. Corenman, M.D., D.C.

Published: March 2017

Journal of the Academy of Chiropractic Orthopedists

March 2017, Volume 14, Issue 1

The original article copyright belongs to the original publisher. This review is available from: http//www.dcorthoacademy.com © 2017 Corenman and the Academy of Chiropractic Orthopedists. This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Authors Abstract

Context: A battery of clinical measures of neurocognition, balance and symptoms has been recommended for the management of sport concussion (SC) but is based on variable evidence.

Objective: To examine the sensitivity and specificity of a battery of tests to assess SC in college athletes.

Design: Cross-sectional.

Setting: Research laboratory

Patients or other participants: Division 1 athletes diagnosed with a SC (n=40) who were 20.2±1.60 years of age and 180.5±11.12 cm tall and healthy athletes (n=40) who were 19.0±0.93 years of age and 179.1 ±11.39 cm tall were enrolled.

Intervention(s): Participants were administered Immediate Postconcussion Assessment and Cognitive Test (ImPACT), the Sensory Organization Test (SOT) and the Revised Head Injury Scale (HIS-r) prior to and up to 24 h following injury between the 2004 and 2014 sport seasons. Sensitivity and specificity were calculated using predictive discriminant analyses (PDA) and clinical interpretation guidelines.


Main outcome measures: Outcome measures included baseline and post injury ImPACT, SOT and HIS-r composite scores.


Results: Using PDA, each clinical measure’s sensitivity ranged from 55.0% to 77.5% and specificity ranged from 52.5% to 100%. The test battery possessed a sensitivity and specificity of 80.0% and 100%, respectively. Using clinical interpretation guidelines, sensitivity ranged from 55% to 97.5% individually, and 100% when combined.


Conclusions: Our results support a multidimensional approach to assess SC in college athletes, which correctly identified 80–100% of concussed participants as injured. When each test was evaluated separately, up to 47.5% of our sample was misclassified.Caution is warranted when using singular measures to manage SC.

Clinical Relevance: Sports concussions are difficult to correctly identify. This study notes that single SC tests have lower acceptable reliability. If however, the three current tests in use are combined, the specificity and sensitivity reach close to 100%.

JACO Editorial Summary:

  1. The article was written by the Exercise and Sport Injury Laboratory Department of Kinesiology at The University of Virginia, Charlottesville, VA and St. Mary’s Athletic Training Research Laboratory, Department of Kinesiology, University of Georgia, Athens, Georgia, USA
  2. The purpose of the study was to investigate the sensitivity and specificity of current testing protocols for sports concussion diagnosis.
  3. The investigative researchers provided a cross-sectional study involving 40 athletes with a diagnosis of sports concussion and compared these individuals to 40 matched controls using three studies; Immediate Postconcussion Assessment and Cognitive Test (ImPACT), the Sensory Organization Test (SOT) and the Revised Head Injury Scale (HIS-r). This was performed prior to and up to 24 h following injury between the 2004 and 2014 sport seasons.
  4. The researchers noted the need for accuracy in sport concussion diagnosis and the reduced sensitivity utilizing only one of these tests. They then discussed how the use of all three tests would increase the sensitivity and specificity for on field diagnosis.
  5. These investigators also noted previous studies and how their current conclusions differ from the previous studies. Previous studies had in some circumstances not enjoined their participants in diagnostic questioning or testing for up to 5 days. This time delay would diminish symptoms necessary for diagnosis and skew the results.
  6. They also note that these athletes included in this study have already agreed with the concussion diagnosis. Many athletes prior to diagnosis might report diminished symptoms upon questioning due to a fear of being withdrawn from competition. There is a “stay in the game” mentality that can reduce the accuracy of diagnosis.

Summary

This study is relevant to the controversial subject of sports concussion syndrome. These concussions can possibly lead to CTE (chronic traumatic encephalopathy) now associated with sports that involve significant impact. Certainly, second impact syndrome can be lethal so diagnosis is so important. The question of testing and test relevance is important as either a missed on-field concussion or falsely diagnosed concussion that takes a player out of action are both failures of treatment.

These authors compared three currently used tests to determine sensitivity and specificity for the Immediate Postconcussion Assessment and Cognitive Test (ImPACT), the Sensory Organization Test (SOT) and the Revised Head Injury Scale (HIS-r). Their conclusions note the need for all three tests to be utilized to deliver the highest sensitivity and specificity.

The question for any chiropractic sports team physician is if there is the time necessary to deliver all three tests and is there a previous baseline test available necessary for the ImPACT conclusions? These tests take 60 minutes so an athlete would effectively be out of the game for this period of time, even if they did not have a concussion.

This study behooves the chiropractic sports team physician to be knowledgeable about these examinations, be prepared to administer the tests and be capable of protecting an athlete by removing them from competition until concussion resolution.

All in all, a good paper and helpful for the chiropractic sports team physician.