Prediction of Unmet Primary Care Needs for the Medically Vulnerable Post-Disaster: An Interrupted Time-Series Analysis of Health System Responses

Abstract

Disasters serve as shocks and precipitate unanticipated disturbances to the health care system. Public health surveillance is generally focused on monitoring latent health and environmental exposure effects, rather than health system performance in response to these local shocks. The following intervention study sought to determine the long-term effects of the 2005 chlorine spill in Graniteville, South Carolina on primary care access for vulnerable populations. We used an interrupted time-series approach to model monthly visits for Ambulatory Care Sensitive Conditions, an indicator of unmet primary care need, to quantify the impact of the disaster on unmet primary care need in Medicaid beneficiaries. The results showed Medicaid beneficiaries in the directly impacted service area experienced improved access to primary care in the 24 months post-disaster. We provide evidence that a health system serving the medically underserved can prove resilient and display improved adaptive capacity under adverse circumstances (i.e., technological disasters) to ensure access to primary care for vulnerable sub-groups. The results suggests a new application for ambulatory care sensitive conditions as a population-based metric to advance anecdotal evidence of secondary surge and evaluate pre- and post-health system surge capacity following a disaster.

Vulnerability of Older Adults in Disasters: Emergency Department Utilization by Geriatric Patients After Hurricane Sandy

“…45,46 On the other hand, ensuring access to primary care health providers serving vulnerable subgroups can represent resiliency and display adaptive capacity under adverse circumstances from natural disasters. [45][46][47] Given the influx of older adult visits to EDs after the storm, local hospitals should anticipate a range of needs typically provided by community-based services. These findings would be magnified by closure of local hospitals or outpatient clinics due to a storm, increasing the burden on emergency medical services workers, physicians, nurses, social workers, hospital administrators, disaster planners, and other medical professionals to meet older adults' disaster care needs.…”

Persistent effects of chlorine inhalation on respiratory health

“…Using validated plume models, individual chlorine exposures were estimated . Over the 3 years following the chlorine release, rates of hospitalization and emergency department visits for ambulatory care–sensitive conditions increased significantly in the Graniteville population compared with a nearby population not exposed to chlorine . In the year following the accident, Graniteville millworkers had significantly reduced FEV 1 , and the prevalence of millworkers with accelerated FEV 1 decline was increased …”

A methodological framework for model selection in interrupted time series studies

“…While ITS is most commonly used for studies of pre-meditated health interventions or health policies, it can also be used to evaluate the health impacts of unplanned events. (36) If the timing of the event is clearly defined, for example: a natural disaster,(37) a chemical spill, (38) or a terrorist attack,(39) then the same modelling process can be used as for planned interventions.…”