Efforts to track health impacts of heat using retrospective data

Paul English, PhD, MPH CA Dept of Public Health

Presented at: National Heat-Health Surveillance Expert Workshop March 17-18, 2015, NYC

Outline

Uses of Retrospective data: Surveillance (where, who, when) Research Reporting Heat Illness/Death Make heat deaths a reportable condition?

Retrospective Data for Surveillance

Climate Change Indicators CSTE CDC Environmental Public Health

Tracking National Climate Assessment

• State Environmental Health Indicators Collaborative on Climate Change • Developed and piloted a suite of 25 environmental, population vulnerability, morbidity and mortality, and policy indicators for climate change. • Included heat-related:

• deaths • hospitalizations • emergency room visits

Source:Environmental health indicators of climate change for the United States: findings from the State Environmental Health Indicator Collaborative. English PB, Sinclair AH, Ross Z, Anderson H, Boothe V, Davis C, Ebi K, Kagey B, Malecki K, Shultz R, Simms E. Environ Health Perspect. 2009 Nov;117(11):1673-81. doi: 10.1289/ehp.0900708. Epub 2009 May 18. Review.

CDC Environmental Public Health Tracking Program

25 states, 1 city (NYC)

Tracking heat illness (emergency room visits, hospitalizations), and heat deaths Heat underlying or contributing cause of death State and county-level May-Sept

Tracking illness/death due to heat only, not related conditions (e.g. cardiovascular, nephritis, etc.)

Not estimating excess morbidity/mortality of specific heat waves

By county in California, 2012 California statewide, 2005-2012

Emergency department visits due to heat among school-aged children (5-17 years old) in California

Data Source: Emergency Department Data, 2005-2012, Office of Statewide Health Planning and Development Provided by: California Environmental Health Tracking Program, www.cehtp.org

• Source: CA Environmental Health Tracking Program

Emergency department visits due to heat in California in summer months, 2005–2010

0

5

10

15

20

25

2005 2006 2007 2008 2009 2010

per 1

00,0

00

Age-Adjusted Rates of Emergency Room Visits for Heat by Race/Ethnicity in California, 2005-2010

blackwhitehispanic

Data Source: Emergency Department Data, 2005-2010, Office of Statewide Health Planning and Development Provided by: California Environmental Health Tracking Program, www.cehtp.org

Heat Deaths (from NCHS mortality data) All States

Heat Illness (ER and Hosp data) Only tracking

states

CDC National Environmental Public Health Tracking

Age-adjusted Rate of Emergency Department Visits for Heat Stress, 2010

Source: National Environmental Health Tracking Program, http://ephtracking.cdc.gov/showHome.action

Deaths attributed to exposure to natural heat, as the underlying and contributing causes of death, are coded as X30 and T67, according to the International Classification of Diseases, 10th Revision. Source: National Vital Statistics System, United States,1999–2010, Weekly, September 14, 2012 / 61(36);729

Number of Heat-Related Deaths by Sex in the U.S. 1999-2010

• EPHT states with the highest rates: Florida, Louisiana, Kansas, Missouri, and South Carolina

Source: Choudhary and Vaidyanathan, MMWR: December 12, 2014 / 63(SS13);1-10

Age-adjusted Rates (per 100,000) of Heat Stress Hospitalizations, 2001-2010

National Climate Assessment

Rate of Heat-Related Mortality in the U.S., 1979-2009

Source: http://www.globalchange.gov/sites/globalchange/files/Pilot-Indicator-System-Report_final.pdf

Establishing Temp-Morbidity Relationships

Percent change in selected hospitalizations with 10 deg F change in mean apparent temp,

9 counties in California

log Source: Green et al 2010

Source: Basu et. al 2012

Heat Wave Research

2011 heat wave in Houston was associated with a 3.6% excess

risk in ED visits (95% CI: 0.6%, 6.6%) (Zhang et al 2015) 2006 Heat wave in CA had 16,166 excess ED visits and 1,182

excess hospitalizations (Knowlton et al 2009)

Issuance of heat alerts in New York City appropriate when the max heat index is forecast to exceed approximately 95-100 degrees F (Metzger et al 2010)

• Estimating Excess Morbidity and Mortality During Heat Events

• Examining Sensitivity to NWS Heat Alerts

Projections of future heat mortality In NYC by the 2050s:

regional increases in heat-related premature mortality ranged from 47% to 95%

mean 70% increase compared with the 1990s (Knowlton et al 2007)

In the UK by the 2050s: heat-related mortality would be expected to rise by around

257% from a current annual baseline of around 2000 deaths (Hajat et al 2014)

In 12 U.S. cities by the end of the century: Nearly 200,000 heat-related deaths are projected to occur

due to climate warming (Petrova et al 2014)

Other Retrospective data

Examining relationship between temperature and ambulance calls

Environ Health. 2012 Jan 24;11(1):3. doi: 10.1186/1476-069X-11-3.

Emergency department visits, ambulance calls, and mortality associated with an exceptional heat wave in Sydney, Australia, 2011: a time-series analysis. Schaffer A1, Muscatello D, Broome R, Corbett S, Smith W. J Epidemiol Community Health. 2011 Sep;65(9):829-31. doi: 10.1136/jech.2009.101485. Epub

2010 Nov 21. The relationship between temperature and ambulance response calls for heat-related illness in

Toronto, Ontario, 2005. Bassil KL1, Cole DC, Moineddin R, Lou W, Craig AM, Schwartz B, Rea E.

Data collected by EMS

Caller Information Patient information EMS Agency Information

Caller’s location* Caller complaint

Level of ambulance service requested by PSAP

dispatch

Patient’s demographics

PSAP call date/time

Onset of symptoms

Patient’s vital signs

Patient’s initial location

Level of ambulance service sent out to patient

Patient’s destination

Provider’s primary and secondary impressions

Patient’s physical appearance

17

Boxes in red are data from PSAPs; boxes in red are data from EMS workers*According to NENA.org, over 95% of the 6,138 PSAPs can detect a wireless caller’s location (i.e., Wireless Phase II). However, not all PSAPs are able to receive this service from all wireless carriers. Psap= 911 public safety answering points

Heat Deaths

Where do people die of heat exposure? Hospital/ER: Death Certificates (attending

physician) Unattended deaths (e.g. isolated elderly): coroner

reports to death certificates Home: Funeral Director to fill out death certificate Exertional Heat Stroke: possible autopsy: coroner

to fill out death cert

Heat Deaths: Reportable?

Pros: Possible increase number of cases reported Possibility for obtaining more info on other factors at time

of death (e.g. social contacts) and could be entered in Electronic Death Record System’s

Cons: Not likely to assist with real-time reporting Real-time surveillance can be achieved with syndromic

surveillance More bureaucracy; resistance by clinicians, others,

compliance issue

Conclusions

Retrospective analysis of heat morbidity and mortality data invaluable in themselves and informing syndromic surveillance : Retrospective surveillance of heat events temporal and spatial patterns of disease temperature/mort-morb algorithms projecting future heat disease burden under different

climate scenarios

Establishing heat deaths as a reportable condition likely of limited value for rapid health surveillance during heat events