Cell Phone Measured Population Mobility and Interactions as a Predictor of Trauma Volume and Trauma Center Need

BackgroundPredicting trauma center need is imprecise with current population-based models. Population activity level may help to estimate trauma demand. We compared daily trauma admissions (TA) and population-level cellular mobility patterns during large fluctuations caused by the COVID-19 pandemic.MethodsTA from all level I trauma centers in one state (January 2020 to August 2021) were aggregated and compared to the Device Exposure Index (DEX), a standardized measure of daily cellular device interactions per county. Mean, standard deviation and range for daily DEX and TA were calculated. Spearman's rank correlation was calculated, followed by regression adjusted for autocorrelation and seasonality. Chi-square test assessed associations between categorized DEX and categorized TA. A 7-day moving average was utilized to smooth values.ResultsThe combined average TA was 17.8 per day (SD 5.5, range 4-38). Mean DEX was 73.6 (SD 32.5, range 6.8-188.4). Both measures declined sharply following pandemic lockdowns and demonstrated parallel trends across centers. TA and DEX were correlated (Spearman's rho = 0.2, <i>P</i> < .001). In regression, DEX remained significantly associated with TA (<i>P</i> < .05). In Chi-square analysis, nearly half (48.2%) of low DEX days (DEX <70) were also low TA days (<17), whereas just over one-third (37.2%) of high DEX days (DEX ≥ 70) were low TA days (<i>P</i> = .008).DiscussionChanges in TA at the onset of the COVID-19 pandemic corresponded with DEX patterns, suggesting DEX may serve as an additional tool to inform trauma system planning, especially during periods of rapid behavioral change. Daily DEX may also provide short-term insight into fluctuations in TA.