Restricted activity and persistent pain following motor vehicle collision among older adults: a multicenter prospective cohort study

BACKGROUND Restricted physical activity commonly occurs following acute musculoskeletal pain in older adults and may influence long-term outcomes. We sought to examine the relationship between restricted physical activity after motor vehicle collision (MVC) and the development of persistent pain. METHODS We examined data from a prospective study of adults ≥65 years of age presenting to the emergency department (ED) after MVC without life-threatening injuries. Restricted physical activity 6 weeks after MVC was defined in three different ways: 1) by a ≥25 point decrease in Physical Activity Scale in the Elderly (PASE) score, 2) by the answer "yes" to the question, "during the past two weeks, have you stayed in bed for at least half a day?", and 3) by the answer "yes" to the question, "during the past two weeks, have you cut down on your usual activities as compared to before the accident?" We examined relationships between each definition of restricted activity and pain severity, pain interference, and functional capacity at 6 months with adjustment for confounders. RESULTS Within the study sample (N = 164), adjusted average pain severity scores at 6 months did not differ between patients with and without restricted physical activity based on decreased PASE score (2.54 vs. 2.07, p = 0.32). In contrast, clinically and statistically important differences in adjusted average pain severity at 6 months were observed for patients who reported spending half a day in bed vs. those who did not (3.56 vs. 1.91, p < 0.01). In adjusted analyses, both decreased PASE score and cutting down on activity were associated with functional capacity at 6 months, but only decreased PASE score was associated with increased ADL difficulty at 6 months (0.70 vs. -0.01, p = 0.02). CONCLUSIONS Among older adults experiencing MVC, those reporting bed rest or reduced activity 6 weeks after the collision reported higher pain and pain interference scores at 6 months. More research is needed to determine if interventions to promote activity can improve outcomes after MVC in older adults.