Steven J. Lippmann

Ambient temperature and emergency department visits for heat-related illness in North Carolina, 2007-2008

PURPOSE To estimate the association between environmental temperatures and the occurrence of emergency department visits for heat-related illness in North Carolina, a large Southern state with 85 rural and 15 urban counties; approximately half the states population resides in urban counties. METHODS County-level daily emergency department visit counts and daily mean temperatures for the period 1/1/2007-12/31/2008 were merged to form a time-series data structure. Incidence rates were calculated by sex, age group, region, day of week, and month. Incidence rate ratios were estimated using categorical and linear spline Poisson regression models and heterogeneity of the temperature-emergency department visit association was assessed using product interaction terms in the Poisson models. RESULTS In 2007-2008, there were 2539 emergency department visits with heat-related illness as the primary diagnosis. Incidence rates were highest among young adult males (19-44 year age group), in rural counties, and in the Sandhills region. Incidence rates increased exponentially with temperatures over 15.6 °C (60 °F). The overall incidence rate ratio for each 1 °C increase over 15.6 °C in daily mean temperature was 1.43 (95%CI: 1.41, 1.45); temperature effects were greater for males than females, for 45-64 year olds, and for residents of rural counties than residents of urban counties. CONCLUSIONS As heat response plans are developed, they should incorporate findings on climate effects for both mortality and morbidity. While forecast-triggered heat health warning systems are essential to mitigate the effects of extreme heat events, public health preparedness plans should not ignore the effects of more persistently observed high environmental temperatures like those that occur throughout the warm season in North Carolina.

Population-based burden of COPD-related visits in the ED: return ED visits, hospital admissions, and comorbidity risks.

BACKGROUND Little is known about the population-based burden of ED care for COPD. METHODS We analyzed statewide ED surveillance system data to quantify the frequency of COPD-related ED visits, hospital admissions, and comorbidities. RESULTS In 2008 to 2009 in North Carolina, 97,511 COPD-related ED visits were made by adults ≥ 45 years of age, at an annual rate of 13.8 ED visits/1,000 person-years. Among patients with COPD (n = 33,799), 7% and 28% had a COPD-related return ED visit within a 30- and 365-day period of their index visit, respectively. Compared with patients on private insurance, Medicare, Medicaid, and noninsured patients were more likely to have a COPD-related return visit within 30 and 365 days and have three or more COPD-related visits within 365 days. There were no differences in return visits by sex. Fifty-one percent of patients with COPD were admitted to the hospital from the index ED visit. Subsequent hospital admission risk in the cohort increased with age, peaking at 65 to 69 years (risk ratio [RR], 1.41; 95% CI, 1.26-1.57); there was no difference by sex. Patients with congestive heart failure (RR, 1.29; 95% CI, 1.22-1.37), substance-related disorders (RR, 1.35; 95% CI, 1.13-1.60), or respiratory failure/supplemental oxygen (RR, 1.25; 95% CI, 1.19-1.31) were more likely to have a subsequent hospital admission compared with patients without these comorbidities. CONCLUSIONS The population-based burden of COPD-related care in the ED is significant. Further research is needed to understand variations in COPD-related ED visits and hospital admissions.

Spatiotemporal Approaches to Analyzing Pedestrian Fatalities: The Case of Cali, Colombia

Objective: Injuries among pedestrians are a major public health concern in Colombian cities such as Cali. This is one of the first studies in Latin America to apply Bayesian maximum entropy (BME) methods to visualize and produce fine-scale, highly accurate estimates of citywide pedestrian fatalities. The purpose of this study is to determine the BME method that best estimates pedestrian mortality rates and reduces statistical noise. We further utilized BME methods to identify and differentiate spatial patterns and persistent versus transient pedestrian mortality hotspots. Methods: In this multiyear study, geocoded pedestrian mortality data from the Cali Injury Surveillance System (2008 to 2010) and census data were utilized to accurately visualize and estimate pedestrian fatalities. We investigated the effects of temporal and spatial scales, addressing issues arising from the rarity of pedestrian fatality events using 3 BME methods (simple kriging, Poisson kriging, and uniform model Bayesian maximum entropy). To reduce statistical noise while retaining a fine spatial and temporal scale, data were aggregated over 9-month incidence periods and censal sectors. Based on a cross-validation of BME methods, Poisson kriging was selected as the best BME method. Finally, the spatiotemporal and urban built environment characteristics of Cali pedestrian mortality hotspots were linked to intervention measures provided in Mead et al.s (2014) pedestrian mortality review. Results: The BME space–time analysis in Cali resulted in maps displaying hotspots of high pedestrian fatalities extending over small areas with radii of 0.25 to 1.1 km and temporal durations of 1 month to 3 years. Mapping the spatiotemporal distribution of pedestrian mortality rates identified high-priority areas for prevention strategies. The BME results allow us to identify possible intervention strategies according to the persistence and built environment of the hotspot; for example, through enforcement or long-term environmental modifications. Conclusions: BME methods provide useful information on the time and place of injuries and can inform policy strategies by isolating priority areas for interventions, contributing to intervention evaluation, and helping to generate hypotheses and identify the preventative strategies that may be suitable to those areas (e.g., street-level methods: pedestrian crossings, enforcement interventions; or citywide approaches: limiting vehicle speeds). This specific information is highly relevant for public health interventions because it provides the ability to target precise locations.

Hospitalizations and return visits after chronic obstructive pulmonary disease ED visits.

PURPOSE The aim of this study was to describe population-based patterns of chronic obstructive pulmonary disease (COPD)-related emergency department (ED) visits. METHODS We analyzed all COPD-related ED visits made by North Carolina residents 45 years or older in 2008 to 2009 using statewide surveillance system data. Return visits were identified when patients returned to the same ED within 3 or 14 days of a prior COPD-related visit. We quantify the prevalence of hospitalization and return visits by age, sex, and payment method and describe ED disposition patterns. RESULTS Nearly half (46.3%) of the 97 511 COPD-related ED visits resulted in hospital admission. The percent of visits preceded by another COPD-related visit within 3 and 14 days was 1.6% and 6.2%, respectively. Emergency department-related hospitalizations increased with age; there were no differences by sex. Hospitalizations were less likely for uninsured, Medicare, and Medicaid visits than for privately insured visits. In contrast, 3- and 14-day return visits were more likely to be uninsured, Medicare, and Medicaid visits than privately insured visits. Fourteen-day returns were more likely to be made by men. Return visits initially increased with age compared with the 45- to 49-year age group, then decreased steadily after age 65 years. When return visits were made, discharge at both visits was the most common disposition pattern. However, 33.7% of 3-day returns and 22.7% of 14-day returns were discharged at the first visit and hospitalized upon returning to the ED. CONCLUSIONS Chronic obstructive pulmonary disease-related hospital admissions and short-term return ED visits were common and varied by age and insurance status. Chronic obstructive pulmonary disease management remains a critical area for intervention and quality improvement.

Defining emergency department asthma visits for public health surveillance, North Carolina, 2008-2009.

Introduction When using emergency department (ED) data sets for public health surveillance, a standard approach is needed to define visits attributable to asthma. Asthma can be the first (primary) or a subsequent (2nd through 11th) diagnosis. Our study objective was to develop a definition of ED visits attributable to asthma for public health surveillance. We evaluated the effect of including visits with an asthma diagnosis in primary-only versus subsequent positions. Methods The study was a cross-sectional analysis of population-level ED surveillance data. Of the 114 North Carolina EDs eligible to participate in a statewide surveillance system in 2008–2009, we used data from the 111 (97%) that participated during those years. Included were all ED visits with an ICD-9-CM diagnosis code for asthma in any diagnosis position (1 through 11). We formed 11 strata based on the diagnosis position of asthma and described common chief complaint and primary diagnosis categories for each. Prevalence ratios compared each category’s proportion of visits that received either asthma- or cardiac-related procedure codes. Results Respiratory diagnoses were most common in records of ED visits in which asthma was the first or second diagnosis, while primary diagnoses of injury and heart disease were more common when asthma appeared in positions 3–11. Asthma-related chief complaints and procedures were most common when asthma was the first or second diagnosis, whereas cardiac procedures were more common in records with asthma in positions 3–11. Conclusion ED visits should be defined as asthma-related when asthma is in the first or second diagnosis position.

Original ResearchCOPDPopulation-Based Burden of COPD-Related Visits in the ED: Return ED Visits, Hospital Admissions, and Comorbidity Risks

BACKGROUND Little is known about the population-based burden of ED care for COPD. METHODS We analyzed statewide ED surveillance system data to quantify the frequency of COPD-related ED visits, hospital admissions, and comorbidities. RESULTS In 2008 to 2009 in North Carolina, 97,511 COPD-related ED visits were made by adults ≥ 45 years of age, at an annual rate of 13.8 ED visits/1,000 person-years. Among patients with COPD (n = 33,799), 7% and 28% had a COPD-related return ED visit within a 30- and 365-day period of their index visit, respectively. Compared with patients on private insurance, Medicare, Medicaid, and noninsured patients were more likely to have a COPD-related return visit within 30 and 365 days and have three or more COPD-related visits within 365 days. There were no differences in return visits by sex. Fifty-one percent of patients with COPD were admitted to the hospital from the index ED visit. Subsequent hospital admission risk in the cohort increased with age, peaking at 65 to 69 years (risk ratio [RR], 1.41; 95% CI, 1.26-1.57); there was no difference by sex. Patients with congestive heart failure (RR, 1.29; 95% CI, 1.22-1.37), substance-related disorders (RR, 1.35; 95% CI, 1.13-1.60), or respiratory failure/supplemental oxygen (RR, 1.25; 95% CI, 1.19-1.31) were more likely to have a subsequent hospital admission compared with patients without these comorbidities. CONCLUSIONS The population-based burden of COPD-related care in the ED is significant. Further research is needed to understand variations in COPD-related ED visits and hospital admissions.

Population-Based Burden of COPD-Related Visits in the ED

BACKGROUND Little is known about the population-based burden of ED care for COPD. METHODS We analyzed statewide ED surveillance system data to quantify the frequency of COPD-related ED visits, hospital admissions, and comorbidities. RESULTS In 2008 to 2009 in North Carolina, 97,511 COPD-related ED visits were made by adults ≥ 45 years of age, at an annual rate of 13.8 ED visits/1,000 person-years. Among patients with COPD (n = 33,799), 7% and 28% had a COPD-related return ED visit within a 30- and 365-day period of their index visit, respectively. Compared with patients on private insurance, Medicare, Medicaid, and noninsured patients were more likely to have a COPD-related return visit within 30 and 365 days and have three or more COPD-related visits within 365 days. There were no differences in return visits by sex. Fifty-one percent of patients with COPD were admitted to the hospital from the index ED visit. Subsequent hospital admission risk in the cohort increased with age, peaking at 65 to 69 years (risk ratio [RR], 1.41; 95% CI, 1.26-1.57); there was no difference by sex. Patients with congestive heart failure (RR, 1.29; 95% CI, 1.22-1.37), substance-related disorders (RR, 1.35; 95% CI, 1.13-1.60), or respiratory failure/supplemental oxygen (RR, 1.25; 95% CI, 1.19-1.31) were more likely to have a subsequent hospital admission compared with patients without these comorbidities. CONCLUSIONS The population-based burden of COPD-related care in the ED is significant. Further research is needed to understand variations in COPD-related ED visits and hospital admissions.