Spatial Accessibility to Hospital Capacity and the Concentration of Health-System Contributions in New Jersey

When a community looks at its healthcare, the first question is often simple: how long does it take to get to a hospital? For decades, researchers have measured this by calculating how many hospital beds a person can reach within a certain drive time. This approach, known as spatial accessibility, treats all hospitals as equal stops on a map, counting the total number of beds available nearby. However, this method misses a crucial detail about the modern healthcare landscape. In recent years, many independent hospitals have joined together under large corporate umbrellas, forming massive health systems. A neighborhood might have plenty of beds within a thirty-minute drive, but if every single one of those beds belongs to the same giant organization, the community has no choice but to rely on that single provider. Understanding whether access is spread across many different organizations or concentrated in just a few is now essential for evaluating the true health of a community.

A researcher set out to map this reality across New Jersey, looking beyond simple travel times to see how hospital capacity is actually distributed among different health systems. They began by identifying every general hospital that a person could reach within a thirty-minute car ride from any neighborhood in the state. They found 163 such hospitals, noting that more than half of the available beds in this network were actually located in neighboring states, highlighting how regional healthcare needs often cross state lines. For each neighborhood, the researcher calculated a score representing the number of staffed hospital beds available per thousand people. This score served as a measure of how much care a community could physically reach.

The study then added a second layer of analysis to see who controlled those beds. Instead of just counting the total, the researcher broke down the contribution of each hospital by the health system it belonged to. They used a method to measure how much of the available care in a neighborhood came from one specific system versus others. If a neighborhood's accessible beds were split evenly among ten different systems, the control was considered dispersed. If nearly all the beds belonged to one system, the control was considered concentrated. This approach allowed the researcher to see not just how much care was available, but how many different hands were offering it.

The results revealed a complex picture of access and control across the state's 2,172 neighborhoods. On average, residents could reach about two staffed hospital beds for every thousand people within a thirty-minute drive. However, when the researcher looked at how those beds were distributed among health systems, they found a significant level of concentration. The average and median concentration scores were 0.36 and 0.31, respectively, indicating that while care was not always dominated by a single system, it was often controlled by a small number of large systems. The data showed that in many neighborhoods, the available care was concentrated within a few health systems, meaning residents had limited choice if those systems made changes to their services or capacity.

Perhaps the most striking finding was that the areas with the least amount of accessible care were often the same areas where that care was most tightly controlled by a single system. The researcher observed that for seven of eight sociodemographic characteristics, the correlations with accessibility and concentration moved in opposite directions. This suggests that the communities most in need of robust, competitive healthcare options are frequently the ones with the least variety in their providers. By looking at both the quantity of beds and the concentration of ownership together, the study provides a clearer view of the healthcare landscape than either measure could offer alone. This dual perspective helps planners and policymakers understand not just where hospitals are located, but how the consolidation of these institutions might affect the choices available to patients in their daily lives.