Reliability of a Novel Return to Duty Screening Tool for Military Clinicians

Lower extremity and low back injuries represent a significant financial burden on the military healthcare system. Subsequent injuries often occur during the recuperation period or in the period directly after physical therapy ends when the patient returns to full duty. Medical providers have relatively few objective tools with which to determine if someone is ready for return to duty (RTD). The purpose of this study is to assess interrater and test-retest reliability of a novel gender-neutral RTD screening tool that requires minimal training, equipment, and time.

This study included 34 active duty military participants (male=22, female=12, age=28.5 ± 5.9). 23 subjects (male=14, female=9, age=28.7 ± 6.3) returned for follow-up testing within one week.

After answering a medical questionnaire, all participants completed the RTD screening tool consisting of: (1) modified anterior reach, (2) modified deep squat, (3) modified trunk stability push-up, (4) modified hip abduction test, (5) forward step-down under low-light conditions, (6) modified Feagin hop test, and (7) perceived risk of future injury. Each individual event was qualitatively scored from 0 to 2 or 3. The composite score ranged from 0 to 16 with higher scores indicating better performance.

For the primary rater, the mean score was 11.26 ± 2.35 during the first trial session and 12.43 ± 1.47 during the second trial session. For the secondary rater, the mean score during the first trial session was 11.38 ± 2.51 and 12.61 ± 1.73 during the second session. There was good interrater reliability for the composite score (intraclass correlation coefficient [ICC] (2,1)=0.88 (0.78, 0.94)). The test-retest reliability was moderate (ICC (3,1)=0.57, (0.21, 0.79)). The chance-corrected agreement was acceptable for all individual events except the modified hip abduction test. There were no significant differences between male and female composite scores.

This novel RTD screening tool showed good overall interrater reliability, suggesting that entry-level clinicians trained on the grading requirements are able to reliably administer the tool. In addition, the screen showed gender-neutrality with no significant differences between men and women. However, the RTD screening tool had only moderate test-retest reliability, suggesting the possible presence of a learning effect. The modified hip abduction test demonstrated poor chance-corrected agreement. Future research should consider including a longer practice session to ameliorate any possible learning effect and to modify the hip abduction test to improve reliability.

This study has demonstrated that a novel RTD screening tool can reliably be administered to an active duty population to assist clinicians in making RTD decisions. However, at this time, it cannot be determined if a certain composite or individual event score will indicate increased risk for injury.