Daily time-series studies with temperature exposures and myocardial infarction (MI) outcomes: description of studies
| First author and year of publication | Population/data source | Location and time period | Number of MI events included (mean MIs/day) | Main temperature exposure variable(s) | Potential confounders included | MI ascertainment | Lags considered (days) |
| Studies of fatal and non-fatal events | |||||||
| Gerber 200614 | County medical care registers | Olmsted County, USA 1979–2002 | 2676 (0.3) | Maximum temperature | Annual population, calendar year, season, rain, snowfall | Diagnoses compatible with MI extracted and validated using cardiac pain, biomarker, and ECG criteria | None |
| Wang 200615 | Ambulance service centre data | Hiroshima, Japan 1993–2002 | 3755 (1.0) | Mean temperature, humidity-adjusted temperature | Atmospheric pressure | Diagnosis based on anamnestic, clinical, laboratory and ECG criteria | None |
| Enquselassie 199316 | MONICA morbidity registry (covering ages <70 years) | Hunter region, New South Wales, Australia 1985–90 | 3889 (1.9) | Maximum temperature | Calendar month, rainfall | Non-fatal definite MI and fatal MI/sudden coronary death, based on MONICA ECG, symptom and enzyme criteria42 | None |
| Ohlson 199117 | Single clinic diagnosis register (ages <70) | Orebro, Sweden 1985–7 (cold seasons only) | 357 (0.6) | Windchill-adjusted temperature (as measured at 7 pm) | Day of week, snowfall, atmospheric pressure | Records with ICD8 code 410.10, 410.99, or ICD9 code 410A/B/W/X | None |
| Barnett 200518 | 24 MONICA morbidity registries (covering ages 35–64 years) | Europe, China, USA, Australia 1980–95 | 87 410 (0.4–2.8 by location) | Mean temperature | Season and trend, day of week, humidity | Non-fatal definite MI and fatal definite/possible MI/unclassifiable event based on MONICA ECG, symptom and enzyme criteria42 | 0–14 inclusive |
| Morabito 200519 | Hospitalisations database (Florentine area) | Florence, Italy 1998–2002 | 2683 (1.5) | Hours of severe discomfort (based on extremes of apparent and windchill temperature indices) | Stratified by season | Records with ICD9 = 410–410.92 | 0–3 inclusive |
| Ebi 200420 | Hospitalisations data (covering all non-federal hospitals) | Three counties in California, USA 1993–8 | 283 031 (4.5–39.4 by location) | Minimum and maximum temperature | Season and trend | Records with ICD9 code 410 | 0, 7, 14, 30 |
| Koken 200321 | Hospital admissions data (11 hospitals, covering ages 65+ years) | Denver county, USA 1993–7 (July and August only) | Not reported | Maximum temperature, dew point temperature | Season and trend, day of week, air pollution variables | Primary discharge diagnosis (ICD9 = 410.XX) | 0–4 inclusive |
| Messner 200222 | Hospital and GP records, and death certificates data (ages 25–64) | Northern Sweden 1985–92 | 3322 (approx 0.9†) | Temperature, change in temperature from previous day | Season, humidity, air pressure, change in humidity and air pressure from previous day | Suspected cases validated using symptom, ECG, and enzyme marker data | None |
| Danet 199923 | Lille-WHO MONICA morbidity registry (covering ages 25–64 years) | Nord district, France 1985–94 | 3314 (approx 0.9†) | Mean temperature | Annual population, mean atmospheric pressure, calendar year | Non-fatal definite MIs and fatal definite/possible MIs, based on MONICA ECG, symptom and enzyme criteria42 | None |
| Fatal events only | |||||||
| Dilaveris 200624 | Death certificate data | Athens territory, Greece 2001 | 3126 (8.6) | Daily mean/minimum/maximum temperature | Atmospheric pressure, relative humidity, season (based on calendar date) | Death certificates with ICD10 codes of I20.0–4, I21.9, I22.0, I22.1, I22.8, I22.9 | Mean of 0, 7 |
| Sharovsky 200425 | Death registry data | Sao Paulo, Brazil 1996–8 | 12 007 (16.4) | Mean temperature | Season and trend, relative humidity, atmospheric pressure, day of week, holidays, influenza levels, air pollution variables | Death certificates with MI (ICD10 = I21) listed as primary cause | 0, and moving average of up to previous 7 days |
| Rossi 199926 | Vital statistics department mortality data | Milan, Italy 1985–9 | Approx 1600* (0.9) | Mean temperature | Season and trend, relative humidity, day of week, holidays, respiratory infection epidemics, pollution variables | Deaths with ICD9 codes of 410 | Different lags considered, exact strategy unclear |
*Derived from reported mean daily rate, and length of period under study; †derived from reported total number of events, and reported length of study.