Which factor helps explain why PAR distribution may shift over time?

• A. Weather
• B. Demographics
• C. Traffic patterns
• D. Staffing levels

Answer: (B)

The factor that explains why PAR distribution may shift over time is demographics. As the population changes in age, health status, and where people live, the mix and location of individuals who are at risk also change. An aging population, for example, increases the proportion of calls related to falls, heart problems, and strokes, and these needs become more concentrated in areas with more older adults. Migration and urban development can create new patterns of disease and service demand in different neighborhoods. Weather, traffic patterns, and staffing levels influence when and how calls are handled, but they don’t fundamentally alter which groups are at higher risk; they mainly affect timing and access. In practice, recognizing demographic shifts helps predict where and what types of EMS resources will be most needed in the future.