Understanding the characteristics of injuries from road traffic collisions among cyclists in Ireland.

In Ireland, cycling is increasing in popularity. High-quality data on serious injuries (SIs) is key to improve cyclist safety. Police-based records, the main data source on road traffic collisions, are likely to underestimate cyclist SIs. This study aimed to understand the injury profile among cyclists in Ireland and inform road safety policy. Two national datasets, hospital records and police-based data (2014-2023), were analysed. A standard definition of SIs (MAIS3+) was applied to hospital records. Chi-square tests and multivariable logistic regression (p<.05) were used to analyse cyclist characteristics (hospital data) and collision patterns (police data). Annual totals across datasets were compared using ratios. There were 5413 hospitalised cyclists (17.7% with MAIS3+ injuries); and 2204 cyclist SIs in police records. There were 8.4 single-cyclist collisions (SCCs) in hospital records for each SCC in police data. Hospitalisations from SCCs increased over time. Hospital data analyses indicated a greater likelihood of MAIS3+ injury from collisions with heavy vehicles (1.9 times) or among older (65+) cyclists (3.9 times), and a lower likelihood among females (0.6 times). Older cyclists were more likely to need continued care (4.1 times) and to have multiple injuries (1.5 times). Police data analyses indicated that SCCs were more likely in summer (1.8 times), weekends (1.5 times), and high-speed roads (1.7 times), and less likely at junctions (0.3 times) or during daytime (0.5 times). Cyclist injury severity varies by age, gender, and collision type. Hospital data is more sensitive to SCCs than police data. Targeted policy measures to reduce SCCs are needed.