Health Policy$ense

Geographic Barriers to Care: the Final Frontier?

Although health reform has reduced many financial barriers to care, it has done little to overcome geographic barriers. Two recent studies by LDI Senior Fellows examine disparities in geographic access to specialty care in the United States, specifically gynecologic cancer care and comprehensive stroke treatment. They assess the potential impact of these disparities on health outcomes, and suggest population-based planning as a way to improve access to specialty care.

Population-based systems planning identifies areas of low access, and optimizes population access by allocating resources to areas of need. The organic development of health systems has led to the clustering of providers in some areas, and sparse distribution of providers in other areas.

Gynecologic cancer care
In Gynecologic Oncology, LDI Fellow David Shalowitz and colleagues identify regions of low access to gynecologic cancer care using as their measurements linear distance from providers and regional referral practices. Previous studies have shown that women who live more than 50 miles from a high-volume hospital (one that does more than 20 ovarian/uterine cancer surgeries a year) use such hospitals less often and are at risk for worse clinical outcomes.

Shalowitz and colleagues find that a large proportion of women - 14.8 million, or 9% of the female population - live in counties that are more than 50 miles from the nearest gynecologic oncologist..  

Compared to counties with better access, low access counties had a lower percentage of Black residents, higher percentage of Hispanic residents, and lower median household income. In addition, these low access counties are more likely to be rural and less likely to be adjacent to a metropolitan area. Interestingly, they find that though Black women have worse clinical outcomes than White women, Black women are no more likely to face distance barriers to gynecological care.

Furthermore, the study shows that 40% of hospital referral regions (HRRs) nationwide do not have a gynecologic oncologist. Hospital referral regions represent geographically defined referral networks that include at least one tertiary care center that provides cardiovascular and neurological procedures for the residents of the HRR. Approximately 15% of women in the U.S. live within these low access HRRs. These women must travel outside the usual referral network for specialized procedures.

Comprehensive Stroke Treatment
In Neurology, LDI Senior Fellows Michael Mullen, Charles Branas, and Brendan Carr share results of a virtual simulation that optimizes access to comprehensive stroke centers (CSCs). CSCs represent the highest level of stroke care, and are critical to ensuring access to stroke treatment. For their virtual trial, the authors selectively converted primary stroke centers (PSCs) to CSCs. Up to 20 PSCs per state were selected for conversion to CSCs, attempting to maximize the population within 60 minutes of a CSC (by ground or air). Access was then compared across states. The study shows that more than 65% of the U.S. population had 60-minute ground access to a PSC before the optimization modeling. The simulation raised that to 86% with ground or air access to a PSC, and to 63.1% with ground access to a CSC.

The authors conclude that even under the optimal conditions of their simulation, a large proportion of the U.S. population will be unable to access a CSC within 60 minutes. This population is at risk of missing out on acute stroke therapies, the effectiveness of which rapidly declines with elapsed time after a stroke.

Mullen and colleagues’ study points to the inefficiency in the current delivery systems of stroke treatment. The authors find that that the marginal increase in population access with each subsequent CSC falls dramatically. Furthermore, population access to CSCs plateaued before all candidate hospitals were used. These findings indicate candidate hospitals are clustered together, and highlight the need for population-based planning to maximize access to stroke therapies.

Population-Based Planning
Shalowitz and the colleagues conclude that “equitable cancer care delivery requires identification and minimization of health disparities, including those related to the geographic distribution to patients’ residences and access points to subspecialty care.” They recommend identifying areas with poor clinical outcomes attributable to geographic factors in order to develop strategies to improve access in those areas.

Mullen and colleagues suggest public health planners use simulation studies such as theirs to identify low access areas and to design interventions to improve access in those areas. Systems planners can use optimization modeling to determine facilities with the greatest impact on access to care. As for rural areas, which have lower access to PSCs than urban areas, the authors recommend that systems planners “carefully assess the local need in rural areas to determine whether there is sufficient need to justify a CSC. If not, alternative strategies, such as PSCs and acute stroke-ready hospitals, may be used to provide basic stroke care, with telemedicine and rapid transfer protocols linking these hospitals to more distant CSCs.”

The studies summarized here point to the need for population-based planning to improve geographic access to care. For both gynecologic oncologic care and stroke care, receiving therapy from a high-volume facility is associated with better health outcomes. Suddenly increasing the number of providers and facilities may decrease the volume of cases at some facilities, and thereby decrease the quality of care at those facilities. Therefore, systems planners need to maintain a certain volume of cases at existing facilities, and simultaneously increase geographic access to care. Data-driven planning can help planners allocate resources in a way that maximizes population access and quality of care.