Towards an embedded symptom validity indicator for the rivermead postconcussion symptom questionnaire

Abstract

This simulation study aimed to develop and test an embedded symptom validity indicator for use with the Rivermead Post Concussion Symptoms Questionnaire (RPQ). Seven mild traumatic brain injury (mTBI) experts assisted in generating a shortlist of 15 atypical postconcussion symptoms. A modified RPQ (mRPQ) was constructed by embedding these items with the 16 standard RPQ items. Eighty-four mTBI simulators completed the mRPQ after random allocation to a symptom-exaggeration condition (ES group; n = 46) or simulation-only condition (S group; n = 38). They also completed the Test of Memory Malingering (TOMM) and the Recognition Memory Test (RMT), and the groups were re-formed and compared using modified criteria for Malingered Neurocognitive Dysfunction (mMND). There was no significant group by item-type interaction for either grouping methods (i.e. as allocated or as reclassified). Exploratory analyses of the main effects showed that ES group had higher mRPQ scores than the S group, and standard symptoms were endorsed more than atypical symptoms. If further developed, the mRPQ could eventually aid the screening of PCS over-reporting.

Keywords:

• Mild traumatic brain injury
• post concussion symptoms
• rivermead post concussion symptoms questionnaire
• symptom validity test

Acknowledgements

The authors thank the School of Psychology and Counselling, Queensland University of Technology (QUT) for funding the gift cards and flyers for this project and the expert reviewers who volunteered to review the items, and Deborah Anderson for assisting with the operationalization of the mMND criteria. This project was approved by the QUT Human Research Ethics Committee (Approval # 1800000471) and the QUT health and safety risk assessment process (Approval # 1011). This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Disclosure statement

The authors report no conflict of interest.

Notes

1 TRACK-TBI = Transforming Research and Clinical Knowledge in TBI.

2 At the start of the experiment an error was identified within the stimuli, and the cases that saw the erroneous stimulus were excluded. This erroneous stimulus was then replaced with the correct stimulus and used in all subsequent examinations.

3 The retention trial was not used in this study.

4 The experts were clinicians and/or researchers with mTBI expertise, each of whom had co-authored at least one relevant peer-reviewed publication.

5 Little’s MCAR test, χ²(4, N = 84)=2.76, p = .599

6 A breach of normality for the atypical items in the allocated-group analysis; and a breach of the homogeneity of variance test for the atypical items for the mMND analysis.