The Validity Of Self-reported Physical Fitness Test Scores

Abstract

During epidemiological studies, investigators often have to rely on a participant's self-reported accounts of their physical activities and performance. Validation of selfreported surveys is necessary to know the accuracy of data collected. PURPOSE To determine the validity of self-reported Army Physical Fitness Test (APFT) scores. METHODS The APFT is administered to all Soldiers in the U.S. Army twice a year. It consists of the maximum number of push-ups (PU) completed in 2 min., the maximum number of sit-ups (SU) completed in 2 min., and a 2-mile run (RUN) for time. As part of a larger study, 144 Army light wheel vehicle mechanics responded to a questionnaire asking them to report the results of each event on their most recent APFT. Actual APFT scores were obtained via a telephone call to each Soldier's individual unit. RESULTS The mean±standard deviation (SD) number of self-reported and actual PU were 65±13 repetitions (reps) and 61±15 reps (p<0.01), respectively. The mean±SD number of self-reported and actual SU were 68±11 and 66±10 (p<0.01), respectively. The mean±SD of self-reported and actual RUN times (min.) were 14.5±1.4 and 14.8±1.4 (p<0.01), respectively. Correlations between selfreported and actual PU, SU, and RUN were 0.84, 0.73, and 0.85, respectively. Bland-Altman plots were constructed and the 95% confidence intervals for the difference between the self-reported and actual values ranged from −20 to 12 repetitions for PU, −18 to 13 repetitions for SU, and −1.2 to 1.8 min. for RUN. CONCLUSION On average, Soldiers tended to over report performance on all APFT events. While individual scores can vary widely, the close correlation between self-reported and actual APFT scores suggests that Soldier-reported APFT values are adequate for most epidemiological studies involving larger sample sizes.