The research team, led by Yineng Chen and Shao Lin of the University at Albany, State University of New York, drew on an unusually rich set of data sources to untangle the relationship between flooding, blackouts, and heart disease. Hospitalization records came from the Statewide Planning and Research Cooperative System, a comprehensive database covering patients across New York State from 2005 through 2021. Flood events were identified using the National Oceanic and Atmospheric Administration’s Storm Events Database, while power outage information was supplied by the New York Department of Public Service. To account for other factors that could confound the association, the researchers incorporated fine particulate matter concentrations modeled with the Community Multiscale Air Quality system, meteorological variables from the New York State Mesonet and the Integrated Surface Database, and a suite of time-varying factors such as seasonality and long-term trends.

Methodologically, the study relied on distributed lag nonlinear models embedded within a quasi-Poisson regression framework, a statistical approach widely used in environmental epidemiology to capture how health risks change over time after an exposure and how those risks may behave nonlinearly with increasing hazard intensity. This design allowed the team to estimate the independent effect of flooding, the independent effect of power outages, and the joint effect of their co-occurrence, all while adjusting for air pollution, weather conditions, and temporal patterns that might otherwise masquerade as hazard effects. The researchers also examined hospital length of stay, treatment costs, comorbid conditions, and threshold levels of exposure, and they compared the periods before and during the COVID-19 pandemic to see whether the pandemic altered the hazard-health relationship.

The headline result is deceptively simple: co-occurrence matters. Flooding and power outages were each independently associated with hospitalizations for total cardiovascular disease and for specific cardiovascular subtypes, but the association was strongest when both hazards occurred together, with the highest relative risk reaching 1.09 (95 percent confidence interval: 1.03 to 1.15). In epidemiological terms, that corresponds to roughly a nine percent increase in cardiovascular hospitalization risk during compound events compared with periods without these hazards. While a nine percent increase may sound modest, cardiovascular disease is the leading cause of death in the United States, and even small proportional increases translate into substantial numbers of excess hospital admissions when large populations are exposed, as they are during major storms that knock out power across entire regions.

Equally important are the thresholds the study identified. Cardiovascular risk rose when flooding persisted for more than three days, and when power outages affected more than 15.3 percent of a community. These cutoffs provide concrete, actionable benchmarks for emergency managers: rather than treating all flood and outage events as equally threatening, preparedness efforts can be concentrated on events that cross these critical windows. The researchers also found that flood and outage events were associated with longer hospital stays and higher levels of comorbidity among admitted patients, suggesting that compound hazards not only push more people into hospitals but may also produce more complicated, resource-intensive admissions.

The burden was not distributed evenly across the population. Stratified analyses revealed stronger joint effects for several cardiovascular subtypes, including hypertension, stroke, and ischemic heart disease. The risks were also amplified among people over 65 years of age, individuals enrolled in Medicaid or lacking insurance coverage, and residents of rural communities. These patterns align with what is known about vulnerability to disasters: older adults are more likely to have preexisting cardiovascular conditions and to depend on electricity-powered medical devices, while rural communities often face longer emergency response times, older infrastructure, and fewer backup resources. Socioeconomically disadvantaged groups, meanwhile, may have less capacity to evacuate, stockpile medications, or weather prolonged outages safely, a disparity documented in prior research on disaster preparedness among older adults.

Season and timing mattered as well. The joint effects of flooding and outages were strongest during winter and spring, seasons when cold temperatures place additional strain on the cardiovascular system. Blood pressure is known to rise in colder conditions, and the physiological stress of a cold, dark, flooded home can compound that burden. Winter storms in the Northeast are also notorious for triggering both flooding and widespread outages simultaneously, meaning the compound-exposure scenario the study examines is not a rare curiosity but a recurring feature of the regional hazard landscape. River flood seasonality in the northeastern United States, concentrated in these colder months, helps explain why the overlap is so common.

The pandemic comparison added a further layer of complexity. The joint occurrence of flooding and power outages showed a larger risk of cardiovascular hospitalization during the COVID-19 period than before it, although the difference was not statistically significant. The authors note that the pandemic disrupted routine healthcare utilization, altered hospital admission patterns, and may have increased the underlying cardiovascular vulnerability of the population, since COVID-19 itself has been linked to cardiovascular complications. The direction of the finding, even without statistical significance, hints that health systems under strain may be less able to absorb the shocks of compound environmental hazards, a concern that resonates as climate change intensifies extreme weather while health systems face recurring pressures.

What makes this study particularly valuable is its shift in perspective. Most environmental health research examines one hazard at a time, estimating the risk of floods here and outages there, as if the world kindly separated its disasters. In reality, the same severe storm that inundates a neighborhood frequently severs its power lines, and the two hazards interact with human physiology and healthcare infrastructure in overlapping ways. Flooding can trigger acute psychological stress, physical exertion during evacuation and cleanup, exposure to cold water, and disruption of medication supplies. Power outages disable home medical devices such as oxygen concentrators and ventilators, knock out traffic signals and emergency services, and force vulnerable people into cold or unsafe conditions. When these mechanisms operate simultaneously, the physiological and logistical stresses multiply, and the new findings suggest the resulting hospitalization risk exceeds what either hazard alone would predict.

The authors argue that their results carry direct implications for emergency management. Identifying susceptible populations, including older adults, Medicaid beneficiaries, uninsured individuals, and rural residents, allows public health agencies to prioritize outreach, backup power for electricity-dependent patients, and early prescription refills before forecasted storms. Deploying preparedness efforts within the critical time windows the study identifies, such as the first days of prolonged flooding and outages crossing the 15.3 percent coverage threshold, could mitigate a meaningful share of the excess cardiovascular burden. As climate change drives more frequent and more intense extreme weather events, the compound-hazard framing may become not just an analytical refinement but a necessity for protecting the millions of people whose hearts bear the hidden costs of a warming, stormier world.

Subject of Research: The joint effects of co-occurring floods and power outages on cardiovascular disease hospitalizations in New York State

Article Title: A dangerous combination: how co-occurring floods and blackouts increase cardiovascular hospitalizations

Article References: Chen, Y., Tangang, R., Sun, Y., Zaloom, S., Guo, L., Song, S., Noor, M. I., Friedman, S., Wang, J., Bassill, N. P., Wang, T.-S., & Lin, S. (2026). A dangerous combination: how co-occurring floods and blackouts increase cardiovascular hospitalizations. Journal of Exposure Science & Environmental Epidemiology. https://doi.org/10.1038/s41370-026-00977-1

Image Credits: AI Generated

DOI: 10.1038/s41370-026-00977-1

Keywords: flooding, power outages, cardiovascular disease, hospitalizations, extreme weather, compound hazards, environmental epidemiology, New York State, hypertension, stroke, ischemic heart disease, vulnerable populations

Volara is a respiratory therapy device designed for secretion mobilization and lung expansion, delivering what clinicians call oscillation and lung expansion therapy, or OLE. The device works through two complementary mechanisms: continuous high-frequency oscillation, which loosens and mobilizes mucus from the airways, and continuous positive expiratory pressure, which helps keep airways open and supports lung expansion. Uniquely, the system can simultaneously administer aerosolized medication through an integrated nebulizer, combining three respiratory therapies into a single unit. It is prescribed for patients with chronic respiratory conditions that impair airway clearance, including bronchiectasis, chronic obstructive pulmonary disease, cystic fibrosis, cerebral palsy, amyotrophic lateral sclerosis, muscular dystrophy, and other neuromuscular disorders. Its portability and ease of use make it suitable for home settings, allowing patients who require long-term airway clearance to receive therapy outside the hospital.

The research team, led by investigators at Mathematica with collaborators at Baxter International and Johns Hopkins School of Medicine, conducted a retrospective descriptive analysis using complete administrative claims and encounter data from the Centers for Medicare and Medicare Services Virtual Research Data Center. They identified Medicare fee-for-service and Medicare Advantage beneficiaries who initiated Volara between January 2023 and June 2025, along with Medicaid fee-for-service and managed care enrollees who started the device during calendar year 2023. Initiation was defined by the earliest claim containing the relevant healthcare procedure codes paired with a supplier identifier specific to the device. Patients needed to be at least five years old and continuously enrolled for twelve months before initiation, and Medicaid enrollees dually eligible for Medicare were excluded to avoid incomplete capture of their utilization.

The two cohorts differed dramatically in their demographic and clinical composition. The Medicare cohort comprised 391 enrollees with a mean age of approximately 68 years, of whom 63 percent were female and 78 percent were non-Hispanic White. The overwhelming majority, 93 percent, had pre-existing bronchiectasis, COPD, or neuromuscular disease, with bronchiectasis alone accounting for 36 percent and bronchiectasis combined with COPD for another 33 percent. The Medicaid cohort of 220 enrollees was strikingly younger, with a mean age of just 21 years and 72 percent under age 21. Its disease distribution was broader and different: 37 percent had bronchiectasis or COPD, but substantial proportions had cerebral palsy at 22 percent, neuromuscular disease at 18 percent, prior COVID-19 at 22 percent, and cystic fibrosis at 7 percent. The Medicaid cohort was also more racially and ethnically diverse and lived in neighborhoods with considerably higher social vulnerability, as measured by the CDC Social Vulnerability Index, with 70 percent classified as high vulnerability compared with 43 percent of Medicare patients.

To assess outcomes, the researchers classified patients into mutually exclusive disease segments and measured emergency department visits and inpatient hospitalizations for respiratory exacerbations, along with associated costs, standardized as annualized rates and per-member-per-month costs to account for varying follow-up times. Respiratory events were captured under a broad tier that included COPD, bronchiectasis, COVID-19, asthma, pneumonia, bronchitis, acute respiratory failure, and unspecified respiratory disorders. Clinical risk was assessed using the Elixhauser Comorbidity Index, while social risk was assigned at the ZIP code level. Because payment information is not reported for most Medicaid managed care encounters, the team imputed costs using fee-for-service claims, deriving average shadow prices stratified by year, state, disease segment, event type, demographics, and proxies for severity such as length of stay.

Among Medicare enrollees, the post-initiation period showed consistently lower respiratory-related emergency department use. Annual emergency visit rates fell from 26.3 to 11.0 per 100 patients, a 58 percent reduction, while associated per-member-per-month costs dropped from 21 dollars to 12 dollars, a 39 percent decline. These differences held across all disease segments, ranging from 44 percent lower among patients with both bronchiectasis and COPD to 70 to 81 percent lower in other segments. Hospitalizations also declined, though more modestly: rates fell from 41.2 to 30.4 per 100 patients, a 26 percent reduction, and hospitalization costs fell 11 percent, from 512 dollars to 456 dollars per member per month. The hospitalization improvements were not uniform, however. Patients with COPD saw rates and costs fall by 38 and 36 percent respectively, while neuromuscular disease patients showed similar rates between periods with slightly higher costs afterward.

Subgroup analyses added further nuance. Emergency department reductions appeared across both clinical risk groups and both age groups, but hospitalization patterns diverged sharply. Among Medicare patients with higher clinical risk, hospitalization rates were 33 percent lower after Volara initiation, whereas lower-risk patients actually saw rates rise 8 percent. Social vulnerability produced a similar split: patients in higher-vulnerability neighborhoods experienced 41 percent lower hospitalization rates and 49 percent lower costs post-initiation, while those in lower-vulnerability areas saw costs rise 30 percent despite modestly lower rates. By age, hospitalization rates fell 25 percent among patients 65 and older but rose 6 percent among younger Medicare beneficiaries. Because the pre-initiation period overlapped the COVID-19 pandemic for many patients, the team ran sensitivity analyses excluding COVID-19-related events, and the overall pattern of lower post-initiation utilization and costs remained qualitatively unchanged. Excluding patients with ALS from the neuromuscular segment also did not meaningfully alter the findings.

The Medicaid picture was considerably messier. Emergency department visit rates were nearly flat, at 31.4 per 100 patients before initiation versus 29.6 after, a 5 percent decline, but associated costs rose 24 percent, from 135 dollars to 168 dollars per member per month. Segment-level patterns conflicted: patients with bronchiectasis or COPD had higher emergency visit rates and dramatically higher costs afterward, neuromuscular disease patients had higher rates but lower costs, and cerebral palsy patients showed lower utilization and costs. Hospitalizations told a more favorable story, with rates 24 percent lower and costs 6 percent lower post-initiation overall, though neuromuscular disease patients again moved against the trend. The authors caution that the smaller Medicaid sample makes these exploratory results especially sensitive to noise.

The study’s limitations are substantial and the researchers are explicit about them. As a purely descriptive one-group pre/post design without a comparison group, the analysis cannot establish causation, and regression to the mean may partly explain the lower post-initiation utilization, since some patients likely began Volara after a period of heightened respiratory morbidity such as a hospitalization. Secular changes in healthcare behavior during and after the pandemic cannot be excluded, claims data contain no information on how often or how long patients actually used the device, and concomitant treatments were not examined. Roughly 80 percent of Medicaid costs were imputed, introducing additional uncertainty, and small sample sizes limit generalizability. The study was funded by Baxter, which manufactures the Volara system, though the analysis was conducted by Mathematica under a data use agreement with CMS.

Despite these caveats, the study fills a genuine gap. Prior literature on related airway clearance therapies, including high-frequency chest wall oscillation and oscillating positive expiratory pressure devices, has reported reductions in hospitalizations and costs, but economic evidence specifically for oscillation and lung expansion therapy has been sparse. By documenting who initiates Volara under public insurance and how their utilization patterns shift, the analysis provides hypothesis-generating context for clinicians and payers alike. The pronounced heterogeneity across disease segments, risk strata, and age groups suggests that any future evaluation of the device’s effectiveness will need to account for the fundamentally different populations served by Medicare and Medicaid, from older adults with smoking-related lung disease to children with genetic and neurologic conditions that impair airway clearance. The authors call for comparative study designs with appropriate confounding adjustment to determine whether the observed favorable trends among Medicare beneficiaries reflect a true treatment effect or the interplay of disease course, patient selection, and broader healthcare dynamics.

Subject of Research: Real-world healthcare utilization and costs among Medicare and Medicaid patients initiating Volara oscillation and lung expansion respiratory therapy

Article Title: Characteristics of Medicare and Medicaid Patients Initiating Volara Respiratory Therapy: A Medical Claims Study

Article References: Characteristics of Medicare and Medicaid Patients Initiating Volara Respiratory Therapy: A Medical Claims Study. (n.d.). https://doi.org/10.1007/s12325-026-03762-6

Image Credits: AI Generated

DOI: 10.1007/s12325-026-03762-6

Keywords: Volara, oscillation and lung expansion therapy, Medicare, Medicaid, bronchiectasis, COPD, healthcare resource utilization, emergency department visits, hospitalizations, medical claims, real-world evidence, respiratory therapy