Study Design:
To determine whether a temporal relationship existed between the introduction of ride sharing services in Southwestern Ontario and the rate of alcohol-related MVCs we performed a retrospective cohort study. This study received prior approval from the Western University Research and Ethics board (HREB #112291).
Data Source:
Using the South Western Ontario Trauma Registry (SWOTR) we performed a retrospective analysis of trauma patients involved in MVCs treated at Victoria Hospital in London, Ontario, Canada. Victoria Hospital is the lead trauma center for Southwestern Ontario and serves as a referral center for a catchment area of 1.7 million patients13. The majority of the patients involved in motor vehicle crashes in this registry are injured outside of the London, Ontario city limits. The SWOTR is managed by the Canadian Institute of Health Information (CIHI)13. Trained data analysts collect and maintain the data within this registry locally and submit monthly reports to CIHI. Patients are included in the registry if either of the following criteria are met. 1) A full trauma team activation was performed; or 2) all of the following apply: the injury severity score (ISS) was greater than or equal to 12, there was an external cause of injury, and the patient was either admitted to hospital, died in the emergency department, or was evaluated in the emergency department but not admitted to hospital13.
Patient Selection and Data Extraction:
The SWOTR was searched for patients involved in motor vehicle crashes treated at Victoria Hospital between April 1, 2013 to March 31, 2019 Pediatric patients, pedestrians struck, and cyclists struck were excluded from the analysis. Motorcycle crashes were included and drivers operating a motorcycle were classified as drivers for the analysis. All patients were included in the primary analysis regardless of position in vehicle (driver vs passenger). Blood alcohol level, age, gender, position in motor vehicle, ISS score, length of stay, discharge status, trauma team activation, date, and location of car crash were all abstracted from the registry.
Outcome:
In Ontario, Uber has been the first ride-sharing platform to arrive in most jurisdictions14. For this reason, we used the arrival of Uber services in the community within which the crash occurred as the date for which ride sharing services commenced. All periods after the arrival of Uber in a community were considered periods for which ride sharing services were available.
The primary outcome was the proportion of patients injured in alcohol related motor vehicle crashes during the period prior to the arrival of ride sharing services compared to the period where ride sharing services were available. The null hypothesis was that there would be no observed difference between these two periods.
For the primary analysis, all patients who arrived with a positive blood alcohol screen, regardless of level, were considered to be involved in an alcohol related car crash. Secondary analysis was performed specifically on patients who were in the driver position of the motor vehicle and had positive blood alcohol concentrations, as well as all patients arriving with blood alcohol levels above the legal limit. An analysis was also performed comparing crashes that occurred in regions that have never had access to ride sharing services compared to those regions that were serviced by Uber at any time during the study period. Descriptive statistics were calculated for all variables. Categorical data are reported as percentages and compared using Pearson’s chi-square test. Analysis of characteristics associated with a positive blood alcohol level was performed using logistic regression. Significance levels for all statistics reported were set at 0.005. Statistical analysis was performed using SPSS vs. 24 (Chicago, Illinois).