Are all AIS data comparable from year to year?

Data from AIS (Abbreviated Injury Scale) is not universally comparable from year to year due to several factors that can influence the data's consistency and interpretation. Changes in the methodology of data collection, updates in the guidelines that dictate how injuries are categorized, and variations in reporting practices can all lead to discrepancies in AIS data across different years.

For instance, if the AIS system is updated to include new injury classifications or to modify existing categories, this can affect how injuries are recorded and reported. Additionally, if there are changes in the protocol for data collection, such as who is responsible for documenting injuries or the criteria used to determine the severity of injuries, these modifications can further impact data comparability.

Without a consistent framework, the comparisons between different years can lead to misleading conclusions if one doesn't account for these variations in the AIS coding and reporting practices. This highlights the importance of using updated and standardized guidelines for accurate longitudinal analysis in injury data.