Measuring Soldier Performance During the Patrol-Exertion Multitask: Preliminary Validation of a Postconcussive Functional Return-to-Duty Metric.

Objective: To assess the discriminant validity of the Patrol-Exertion Multitask (PEMT), a novel, multidomain, functional return-to-duty clinical assessment for active duty military personnel.

Design: Measurement development study.

Setting: Nonclinical indoor testing facility.

Participants: Participants (N=84) were healthy control (HC) service members (SMs; n=51) and military personnel (n=33) with persistent postconcussive symptoms receiving rehabilitation (mild traumatic brain injury [mTBI]).

Interventions: Not applicable.

Main Outcome Measures: Known-groups discriminant validity was evaluated by comparing performance on the PEMT in 2 groups of active duty SMs: HCs and personnel with mTBI residual symptoms. Participant PEMT performance was based on responses in 4 subtasks during a 12-minute patrolling scenario: (1) accuracy in identifying virtual improvised explosive device (IED) markers and responses to scenario-derived questions from a computer-simulated foot patrol; (2) auditory reaction time responses; (3) rating of perceived exertion during stepping; and (4) self-reported visual clarity (ie, gaze stability) during vertical head-in-space translation while stepping.

Results: Significant between-group differences for the PEMT were observed in 2 of 4 performance domains. Postpatrol IED identification task/question responses (P=.179) and rating of perceived exertion (P=.133) did not discriminate between groups. Participant self-report of visual clarity during stepping revealed significant (P<.001) between-group differences. SM reaction time responses to scenario-based auditory cues were significantly delayed in the mTBI group in both the early (P=.013) and late (P=.002) stages of the PEMT.

Conclusions: Findings from this study support the use of a naturalistic, multidomain, complex clinical assessment to discriminate between healthy SMs and personnel with mTBI residual symptoms. Based on this preliminary study, additional research to further refine the PEMT and extend its application to return-to-work outcomes in military and civilian environments is warranted.