Factor structure of the modified Rivermead Post-concussion Symptoms Questionnaire (mRPQ): an exploratory analysis with healthy adult simulators

ABSTRACT

Objective

Persistent postconcussion symptoms (PPCS) are challenging to diagnose. An improved diagnostic process could consider typical and atypical postconcussion symptoms. This study examined the structure of a modified Rivermead Post-concussion Symptoms Questionnaire (mRPQ) with both symptom types.

Method

298 adult volunteers were randomized into groups: honest responders, mild traumatic brain injury (mTBI) simulators (MS), and biased mTBI simulators (BMS). Both mTBI simulating groups were coached about mTBI and primed about the simulation context (compensation evaluation). The BMS group was also encouraged to bias (exaggerate) symptoms. The participants completed an online battery of tests, including the mRPQ.

Results

An exploratory factor analysis of the mRPQ (full sample) revealed a three-factor solution, including a separate dimension for atypical symptoms (all item loadings >0.45, ~4% of explained variance). The overall and group analyses of the standard RPQ items (typical symptoms) found a one- or two-factor solution, as did the analyses of atypical symptoms.

Conclusions

Consistent with prior RPQ research, a unidimensional or bifactor structure was measurable from standard RPQ symptoms. Whilst this study did not find support for domain-level symptom scores for either typical or atypical symptoms, the findings support the use of an overall atypical symptoms score.

KEYWORDS:

• Mild traumatic brain injury
• minor head injury
• concussion
• postconcussive syndrome
• symptom validity
• response bias
• symptom exaggeration
• invalid responding

Acknowledgments

This project was approved by the QUT Human Research Ethics Committee (HREC approval number: 1900001173). The risk assessment for this project was approved by the QUT (approval number: 1331). The QUT School of Psychology and Counselling funded the gift cards for this project. The authors did not receive external funding for this research. The authors have no conflicts of interest to declare.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Plass et al. (2019) used a non-English version of the RPQ in a sample of mild-to-severe TBI patients.

2. Transforming Research And Clinical Knowledge in Traumatic Brain Injury [(TRACK)-TBI] refers to a large, multi-site, longitudinal investigation of TBI outcomes in North America.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.