Comparison of Methods for Classifying Persistent Post-Concussive Symptoms in Children

Abstract

Pediatric mild traumatic brain injury (pmTBI) has received increased public scrutiny over the past decade, especially regarding children who experience persistent post-concussive symptoms (PPCS). However, several methods for defining PPCS exist in clinical and scientific literature, and even healthy children frequently exhibit non-specific, concussive-like symptoms. Inter-method agreement (six PPCS methods), observed misclassification rates, and other psychometric properties were examined in large cohorts of consecutively recruited adolescent patients with pmTBI (n = 162) 1 week and 4 months post-injury and in age/sex-matched healthy controls (HC; n = 117) at equivalent time intervals. Six published PPCS methods were stratified into Simple Change (e.g., International Statistical Classification of Diseases and Related Health Problems, 10th revision [ICD-10]) and Standardized Change (e.g., reliable change indices) algorithms.Among HC, test-retest reliability was fair to good across the 4-month assessment window, with evidence of bias (i.e., higher symptom ratings) during retrospective relative to other assessments. Misclassification rates among HC were higher (>30%) for Simple Change algorithms, with poor inter-rater reliability of symptom burden across HC and their parents. A 49% spread existed in terms of the proportion of pmTBI patients ''diagnosed'' with PPCS at 4 months, with superior inter-method agreement among standardized change algorithms. In conclusion, the self-reporting of symptom burden is only modestly reliable in typically developing adolescents over a 4-month period, with additional evidence for systematic bias in both adolescent and parental ratings. Significant variation existed for identifying pmTBI patients who had ''recovered'' (i.e., those who did not meet individual criteria for PPCS) from concussion across the six definitions, representing a considerable challenge for estimating the true incidence rate of PPCS in published literature. Although relatively straightforward to obtain, current findings question the utility of the most commonly used Simple Change scores for diagnosis of PPCS in clinical settings.

Resting‐State Power and Regional Connectivity After Pediatric Mild Traumatic Brain Injury

“…First, multiple clinical and research definitions exist for identifying patients with persistent-PCS, and these various definitions can result in a 49% spread in patient classification rates. 4 This is likely a result of the nonspecific nature of PCS symptoms and normal fluctuations in symptom load, 5 which complicates the identification of nonrecovered patients based on subjective complaints only. 49 When adopting more conservative criteria, the number of pmTBI classified as having persistent-PCS in the current sample (N = 19; 18.1%) was approximately half compared to other large-scale clinical studies using more simple clinical criteria for persistent-PCS (30-33%; 3 ), thereby limiting statistical power.…”

“…Classification of persistent-PCS from recovered patients at the 4-month follow-up visit (EC) was determined based on self-reported PCSI data. 4 Briefly (see Appendix S1 in the Supplemental Material), individual HC and pmTBI PCSI data at the EC visit were summed, base 10 log-transformed to correct for nonnormality, and further corrected relative to HC for distributional bias in nonindependent Z-scores (Z HC [persistent-PCS] > 1.64). Those pmTBI above the threshold were identified as having persistent-PCS, while those below the threshold were classified as recovered.…”

“…The exact number of children who continue to exhibit postconcussive symptoms (PCS) 1 month or more postinjury (henceforth identified as persistent-PCS) remains actively debated. 2 Some estimates suggest 30-35% of children do not recover by 4 months postinjury, 3 whereas others indicate a lower (10-15%) estimate 4 when accounting for the nonspecific nature of symptom reporting. 5 Recently, it has been suggested that resting-state connectivity 6 may be more sensitive than self-report measures for not only detecting the acute to subacute effects of injury, but also for identifying patients who may remain symptomatic.…”

“…The exact number of children who continue to exhibit postconcussive symptoms (PCS) 1 month or more postinjury (henceforth identified as persistent‐PCS) remains actively debated 2 . Some estimates suggest 30–35% of children do not recover by 4 months postinjury, 3 whereas others indicate a lower (10–15%) estimate 4 when accounting for the nonspecific nature of symptom reporting 5 …”

Characteristics of Pediatric Mild Traumatic Brain Injury and Recovery in a Concussion Clinic Population

“…However, much of the research regarding mild TBI recovery comes from emergency or acute care cohorts using relatively short outcome windows (ie, Յ1 month). 7,10,11 Currently, there is no widely accepted definition or time interval for PPCS in children, 12 further challenging clinicians' ability to identify and treat these patients. Moreover, factors associated with PPCS and prolonged recovery may differ in different clinical populations (eg, athletes vs nonathletes, adolescents vs children), clinical settings (eg, specialty concussion clinics having a higher proportion of subacute or chronic patients with PPCS than primary care clinics) and time intervals (eg, 1 month vs Ն3 months after injury).…”