Smoothed conditional mean plots visualizing the variation of incidence rates of myocardial infarction with 95% CI by different weather parameters. Unadjusted and adjusted incidence rate ratio (IRR) and 95% CI from regression analyses are presented with each graph. Results from the regression analyses are interpreted as change per increase in standard deviation. One standard deviation for air pressure, 10.9 kPa; change in temperature (Δ temperature), 3.4°C; humidity, 9.6%; rain, 2.6 mm; snow, 0.25 mm; sunshine duration, 4.2 hours; wind velocity, 1.9 m/s. IRR1 indicates univariable model; IRR2, multivariable model; NSTEMI, non–ST-elevation myocardial infarction; and STEMI, ST-elevation myocardial infarction.
aP < .05.
bP < .01.
cP < .001.