Is a brief retrospective interview a valid and reliable assessment of duration of post-traumatic amnesia after mild-moderate head injury?

Introduction: Duration of Post-Traumatic Amnesia (PTA) following head injury (HI) can be assessed prospectively, during the amnesic period, or retrospectively, after the amnesic period has resolved. Prospective assessment of PTA can be difficult after less severe injuries because PTA duration is sho...

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Bibliographic Details
Main Author: Bell, Kirsty
Published: University of Glasgow 2010
Subjects:
155
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.524025
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Summary:Introduction: Duration of Post-Traumatic Amnesia (PTA) following head injury (HI) can be assessed prospectively, during the amnesic period, or retrospectively, after the amnesic period has resolved. Prospective assessment of PTA can be difficult after less severe injuries because PTA duration is short. Retrospective assessment could be more practical but may be less valid and reliable. This study explores the reliability and validity of a retrospective assessment interview [1] for mild-moderate HI by examining the relationship between initial and follow-up estimates of PTA duration, and the relationship between estimates of PTA duration and outcome. Methods: Patients admitted to Glasgow Royal Infirmary following a HI were invited to take part in the study and completed the initial PTA assessment on the proposed day of discharge. Participants were contacted by telephone one to six weeks later to complete the follow-up assessment of PTA and the GOS-E. Results: Twenty-two participants completed the study. According to the Glasgow Coma Scale (GCS) twenty-one were classified as having sustained a mild HI and one as having sustained a moderate HI. Initial and follow-up estimates of PTA duration were highly positively correlated (rho=0.704), illustrating a large effect size. No significant relationships were found between estimates of PTA duration and outcome on the GOS-E. Conclusions: A retrospective assessment interview is of great clinical relevance for patients with mild-moderate HI who often present to medical services after having emerged from PTA. This type of assessment can be used to obtain a reliable estimate of PTA duration after mild-moderate HI; however, further research into the validity of the interview is required.