Table 3
Daily time-series studies with temperature exposures and myocardial infarction (MI) outcomes: study results
| First author and year | Temperature variable*, range (if reported) (°C) | Relative risk (RR) or rate ratio for temperature (95% CI if reported) | (Change in temperature variable to which RR refers) | Subgroup to which RR refers (if applicable) | Lag for temp effect (days) | Comment |
| Studies of fatal and non-fatal events | ||||||
| Gerber 200614 | tmax −29 to 39 | 0.93 (0.73 to 1.14) | >30°C | 0 | – | |
| 1.00 (reference) | 18–30°C | |||||
| 0.97 (0.89 to 1.06) | 0–17°C | |||||
| 1.03 (0.92 to 1.14) | <0°C | |||||
| Wang 200615 | tmean −0.9 to 32.7 | 1.00 (reference) | >20°C | 0 | – | |
| 1.12 (0.99 to 1.27) | 10–20°C | |||||
| 1.17 (1.01 to 1.35) | <10°C | |||||
| Enquselassie 199316 | tmax <16 to >30 | 1.2 (0.9 to 1.5)* | >30°C | Fatal MIs | 0 | – |
| 1.0 (reference) | 23–27°C | Fatal MIs | ||||
| 1.4 (1.1 to 1.8)* | ⩽16°C | Fatal MIs | ||||
| 1.2 (0.9 to 1.4)* | >30°C | Non-fatal MIs | ||||
| 1.0 (reference) | 23–27°C | Non-fatal MIs | ||||
| 1.0 (0.8 to1.3)* | ⩽16°C | Non-fatal MIs | ||||
| Ohlson 199117 | twind <−20 to >0 | 1.00 (reference) | ⩾0°C | 0 | – | |
| 1.09 (0.82 to 1.44) | −10 to −1°C | |||||
| 1.10 (0.79 to 1.52) | −20 to −11°C | |||||
| 1.12 (0.67 to 1.85) | <−20°C | |||||
| Barnett 200518 | tmean 1.5 to 23.0 | 1.008 (1.004 to 1.012) | Per 1°C decrease | Average 0–3 | Only a linear temperature effect appears to have been considered | |
| Morabito 200519 | tmean, discomfort hours | 1.03 (p<0.01) | Per extra two heat discomfort hours | Summer, men, <65 years | 0 | Only linear effects of the exposure variables appear to have been considered. However, discomfort hours analysis was performed separately for winter and summer |
| 1.06 (p<0.01) | Per extra two cold discomfort hours | Winter, women, <65 years | ||||
| Ebi 200420 | tmin, tmax −1 to 37 (tmin) | 1.072 (1.057 to 1.086) | Per 3°C decrease (tmin) | Men, 55–69 years, LA | 7 | Only linear temperature effects appears to have been considered. Effects for age ⩾70 years and for women were all in the same direction as those shown here |
| 1.008 (1.004 to 1.012) | Per 3°C increase (tmin) | Men, 55–69 years, SF | ||||
| 1.223 (1.083 to 1.381) | Per 3°C increase (tmin) | Men, 55–69 years, Sa | ||||
| 1.025 (1.000 to 1.052) | Per 3°C increase (tmax) | Men, 55–69 years, LA | ||||
| 1.066 (1.023 to 1.111) | Per 3°C decrease (tmax) | Men, 55–69 years, SF | ||||
| 1.109 (1.051 to 1.169) | Per 3°C decrease (tmax) | Men, 55–69 years, Sa | ||||
| Koken 200321 | tmax 16.7 to 30.8 | 1.175 (1.029 to 1.343) | Per 5.9°C increase | ⩾65 years | 0 | Analysis was for July/August only |
| Messner 200222 | temp, tchange −38 to 30 (temp) | 1.001 (0.993 to 1.008) | Per 1°C decrease (temp) | Fatal MIs | 0 | Only linear temperature effects appears to have been considered |
| 1.000 (0.997 to 1.003) | Per 1°C increase (temp) | Non-fatal MIs| | ||||
| 1.003 (0.979 to 1.028) | Per 1°C increase (tchange) | Fatal MIs | ||||
| 1.015 (1.003 to 1.027) | Per 1°C increase (tchange) | Non-fatal MIs | ||||
| Danet 199923 | tmean −15 to 28 | 1.05 (1.02 to 1.09) | Per 5°C decrease | 0 | Only linear temperature effects appears to have been considered | |
| Fatal events only | ||||||
| Dilaveris 200624 | tmean 1 to 39 | 1.13†1.00 (reference) | 30°C23.3°C | Mean of last 7 days | Results are from the regression line, which shows minimum event rate at 23.3°C, with the event rate increasing smoothly above and below this temperature (levelling off at mean temperatures below 10°C) | |
| 1.40† (p<0.001) | 10°C | |||||
| Sharovsky 200425 | tmean 11 to 27 | 1.11 (1.06 to 1.16)†1.00 (reference) | 23.8–27.3°C21.6–22.6°C | 2-Day average | – | |
| 1.16 (1.05 to 1.27)† | 16.4–17.3°C | |||||
| 1.17 (1.07 to 1.28)† | 15.2–16.4°C | |||||
| 1.31 (1.19 to 1.44)† | 11.0–15.2°C | |||||
| Rossi 199926 | tmean −6 to 32 | 1.44 (1.10 to 1.90) | >27°C | 1 | Effect of colder temperatures is not described | |
| 1.00 (reference) | 14°C | |||||
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Percentage changes were converted to relative risk by dividing by 100 and adding one.
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*tmax, daily maximum temperature; tmin, daily minimum temperature; tmean, daily mean temperature; temp, temperature (unspecified); discomfort, number of discomfort hours per day; tchange, temperature change from previous day; twind, windchill-adjusted temperature; †approximate RR, derived from graphical presentation of results.
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LA, Los Angeles region; Sa, Sacramento region; SF, San Francisco region.
