Measure Description

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STATE ENVIRONMENTAL HEALTH INDICATORS COLLABORATIVE (SEHIC) CLIMATE AND HEALTH INDICATORS Category: Health Outcome Indicators Indicator: Allergic Disease

MEASURE DESCRIPTION

Measure: Allergic disease related hospital admissions (number, rate) Allergic disease related emergency discharges (number, rate) Time scale: Calendar year Measurement units: Annual, seasonally Geographic scale: County, State, & Multi-state Background and Over the past century, the overall global surface temperature has increased by 0.7– significance: 1.4°F1. Continuing climate change is expected to have an impact on the occurrence of extreme temperature days and weather patterns, which can affect allergic disease. Higher temperatures in heat waves accelerate chemical reactions that lead to ozone and secondary particle formation. Higher temperatures and elevated carbon dioxide concentrations also lead to increased emissions of volatile organic compounds (VOCs) by vegetation, which serve as ozone precursors2. Air pollution plays a significant and complex role in the etiology of allergic disease, as well as on the effect aeroallergens have on these diseases3. Furthermore, it has been hypothesized that climate change will play a role in aeroallergen (pollens, molds, and indoor proteins) concentrations6, and weather patterns influence movement and dispersion of air pollutants. Changes in climate will likely affect aeroallergen production7,8, the timing and length of pollen season9, and distributions of pollen producing species10. Each of these will influence human exposure, sensitization, and exacerbation of illness.

Allergies and asthma collectively cost over $30 billion annually in the U.S., and 54.5% of people in the U.S. test positive for an allergic response to one or more allergen4. Allergic diseases primarily associated with aeroallergens include allergic rhinitis (hay fever; 477, J30.1), asthma (493, J45), atopic dermatitis (eczema; 691.8, L20), allergic urticaria (hives; 708.0, L50.0), and allergic conjunctivitis (372.14, H10.1) 4,11. Children’s health is particularly susceptible to environmental pollution, including air pollution, and infant mortality is still a major contributor to childhood mortality12. Asthma, affected by both air pollution and aeroallergens, is the predominant chronic disease of childhood. It affects approximately 4.8 million US residents, and is the chief cause of school absenteeism and child hospitalization13. Furthermore, 15-20% of children world- wide suffer from atopic dermatitis, and this figure is increasing13. Children and adults who live in urban areas are at an increased risk from pollen-induced respiratory allergy14, air pollution21, and exposure to a higher heat index21.

There are relatively few studies that investigate linkages between climate change and allergic disease health outcomes15,16,17,18. The potential confounding and effect modification caused by temperature interacting with air pollutants, aeroallergens, and health outcomes is also a complex issue, with varying results depending on pollutant, geography, climate, and sensitization that can not be overlooked19,20,14. This health outcome indicator will attempt to track allergic disease. The indicator will be particularly useful to study trends that may occur with changing climate. Rationale: A hypersensitive reaction of the immune system to a normally harmless environmental substance is an allergy. An aeroallergen is any of various airborne substances, like pollen or spores that can cause an allergic response. Aeroallergens are expected to increase and change distribution with climate change7, 8, 9, 10, thus effecting allergic disease.

Allergic diseases primarily associated with aeroallergens include allergic rhinitis (hay fever; 477, J30.1), asthma (493, J45), atopic dermatitis (eczema; 691.8, L20), allergic urticaria (hives; 708.0, L50.0), and allergic conjunctivitis (372.14, H10.1) 4, 11 and can be tracked or monitored along with pollen and other major allergens.

The economic impacts of allergic disease, and the quality of life impacts for those affected, are already significant. Climate change-induced amplification of this trend would be of great consequence. It is important to understand as much as possible about these complex relationships to improve health outcomes. This indicator will be useful in tracking trends in allergic disease that can be linked to other climate related indicators.

Measurements may have different meanings during the winter versus the summer seasons. By measuring at this seasonal time scale, we will be able to investigate these within year temporal effects for each indicator. Limitations of measure: In addition to various aeroallergens, many important non-climate factors such as ambient air pollutants, environmental conditions at home, land use patterns, and host species abundance etc., can play a role in allergic health outcomes. Therefore these factors should be considered and controlled in the indicator analysis. Some allergic diseases may also be related to climate factors, or have an indirect, complicated, or unknown relationship to climate change. A challenge would be to fully understand the mechanism in which climate change affects aeroallergen concentration and distribution and then allergic diseases. Data source: Vital Records, Hospital Admission Records, Emergency Discharge Data Limitations of data Some states will not have emergency discharge data; this will likely lead to under- source: ascertainment of data for mild cases. Furthermore, hospitalization data are typically released annually, after a data preparation period, which can take one to two years. This will delay the calculation of these indicators. To minimize confusion, it is important to note that data sources use different codes (ICD-9 or ICD-10) depending on the state, and that, within a state, data sources may use different codes as well.

Related datasets: National Allergy Bureau, NCDC/NOAA North American Pollen Database, Census data from U.S. Bureau of the Censuses, historic average temperature data, and AQS air quality data for particulate matter and ozone, NCDC/NOAA daily weather conditions (temperature, humidity, ect.) Additional data Month of year, season, age, gender, race, and ethnicity elements:

References:

1National Research Council. 2000. Reconciling observations of global temperature change. Washington, DC: National Academy Press, 86

2 Hogrefe C, et al. 2005. Considering climate change in air quality management. Environment Manager:19-23.

3 D’Amato, G et al. 2001. The role of outdoor air pollution and climatic changes on the rising trends in respiratory allergy. Respiratory Medicine, 95(7):6066-11.

4 Reid, Colleen and Janet Gamble. 2009. Aeroallergens, Allergic Disease, and Climate Change: Impacts and Adaptation. EcoHealth. Epub before print DOI:10.1007/s10393-009-0261-x

5 Knowlton, K et al. 2007. Sneezing and wheezing: how global warming could increase ragweed allergies, air pollution, and asthma. Natural Resource Defense Coucil. http://www.nrdc.org/globalWarming/sneezing/sneezing.pdf. Accessed 22 Feb 2010.

6 Beggs, PJ and Bambrick HJ, 2005. Is the global rise of asthma and early impact of anthropogenic climate change? Environmental Health Perspectives, 113(8):915-19.

7 Freye HB et al. 2001. Variations of pollen and mold concentrations in 1998 during the strong El Nino event of 1997-1998 and their impact on clinical exacerbations of allergic rhinitis, asthma, and sinusitis. Allergy and Asthma Proceedings, 22:239-47.

8 Wan S. et al. 2002. Response of an allergenic species, Ambrosia psilostachya (Asteraceae), to experimental warming and clipping: implications for public health. American Journal of Botany, 89(11):1843-46.

9 Root TL, et al. 2003. Fingerprints of global warming on wild animals and plants. Nature, 421(6918):57-60.

10 Fischlin A, et al. 2007. Ecosystems, their properties, goods, and services. Climate Change 2007: Impacts, Adaptation, and Vulnerability. Cambridge UK: Cambridge University Press, pp 211-272.

11 Kinney, Patrick L. 2008. Climate Change, Air Quality, and Human Health. American Journal of Preventative Medicine, 35(5):459-67

12 Glinianaia, SV, et al. 2004. Does particulate air pollution contribute to infant death? A systematic review. Environmental Health Perspectives. 112(14):1365-71.

13 O’Connell, EJ. 2004. The burden of atopy and asthma in children. Allergy, 59(78S)7-11.

14 D’Amato, G and Cecchi, L. 2008. Effects of climate change on environmental factors in respiratory allergic disease. Clinical Experimental Allergy. 38(8):1264-74.

15 Epton, MJ et al. 1997. Climate and aeroallergen levels in asthma: a 12 month prospective study. Thorax, 52(6):528-34.

16 Garty, DZ et al. 1998. Emergency room visits of asthmatic children, relation to air pollution, weather, and airborne allergens. Annals of Allergy, Asthma, and Immunology, 81(6):563-570

17 Heguy, L et al. 2008. Associations between grass and weed pollen and emergency department visits for asthma among children in Montreal. Environmental Research, 106(2):203-211.

18 Suarez-Varela, MM et al. 2008. Climate and prevalence of atopic eczema in 6-7 year old school children in Spain. ISAAC PhASE III. International Journal of Biometeorology, 52(8):833-40

19 Erbas B, et al. 2007. Do levels of airborne grass pollen influence asthma hospital admissions? Clinical and Experimental Allergy, 37(11):1641-1647.

20 Tobias, a. et al. 2004. Non-linear short-term effects of airborne pollen levels with allergenic capacity on asthma emergency room admissions in Madred, Spain. Clinical and Experimental Allergy, 34(6):871-78

21 Lai, LW and Cheng WL. 2010. Urban heat island and air pollution-an emerging role for hospital respiratory admissions in an urban area. Journal of Environmental Health, 72(6):32-5

How-To-Guide – Respiratory and allergic deaths, hospital admissions, and emergency discharges, AQS air data, and climate change data

I. Hospitalizations due to Allergic Disease

1. Calculate Number of Hospitalizations due to Allergic Disease a. From the statewide hospital discharge file (from State Health Department, Hospital Association, etc.) obtain the number of hospitalizations that meet these criteria (do not include emergency department data):  Principal (primary) discharge diagnosis of 493, 477, 691.8, 708.0 or 372.14 (ICD-9- CM) or J45, J30.1, L20, L50.0 or H10.1 (ICD-10-CM).  State of residence = ‘your state’  Use data that are not de-duplicated (do not exclude for deaths, readmissions)  Use admission date during calendar year, not fiscal year. Retain the day of admission.  Exclude admissions of: o Out-of-state residents and unknown residence o Out-of-state hospitalizations o Transfers from another hospital (using the source of admission code in the hospital discharge dataset, eg. If HCUP format, exclude source=2). b. Obtain the number of hospitalization for the following disease groups by stratifying data:  Allergic Diseases o Asthma (493 or J45) o Allergic rhinitis (hay fever) (477 or J30.1) o Atopic dermatitis (eczema) (691.8 or L20) o Allergic urticaria (hives) (708.0 or L50.0) o Allergic conjunctivitis (372.14 or H10.1)

2. Calculate Rate of Hospitalizations due to Allergic Disease a. Stratify into the correct geographic scale by using the county or ZIP fields from the hospitalization records b. Use the Census 2000 aggregated block population that fits within the boundary of your chosen area as the denominator to calculate the rate

II. Emergency Department Visits due to Allergic

1.Calculate Number of Emergency Discharges due to Allergic Disease a. From the statewide emergency discharge file (from State Health Department, etc.) obtain the number of emergency discharges that meet these criteria :  Principal (primary) discharge diagnosis of 493, 477, 691.8, 708.0 or 372.14 (ICD-9- CM) or J45, J30.1, L20, L50.0 or H10.1 (ICD-10-CM).  State of residence = ‘your state’  Use data that are not de-duplicated (do not exclude for deaths, readmissions)  Use date during calendar year, not fiscal year. Retain the day of visit.  Exclude discharges of: o Out-of-state residents and unknown residence o Out-of-state hospitalizations b. Obtain the number of hospitalization for the following disease groups by stratifying data:  Allergic Diseases o Asthma (493 or J45) o Allergic rhinitis (hay fever) (477 or J30.1) o Atopic dermatitis (eczema) (691.8 or L20) o Allergic urticaria (hives) (708.0 or L50.0) o Allergic conjunctivitis (372.14 or H10.1)

Notes:

If counts in any year are less than 5, than please report data in 5 year intervals.

Data should be reported as state level data rather than county level data if appropriate.