Table 6.
ORs and 95% CIs for ED visits for HI on lag day 2 above vs. below the threshold from single-day lag models in Anchorage, Fairbanks, and the Matanuska-Susitna Valley, Alaska, 2015–2019.
| Reason for ED visit | Number of cases | 21.1°C (70°F) HI threshold | 22.2°C (72°F) HI threshold | 23.3°C (74°F) HI threshold | 24.4°C (76°F) HI threshold | 25.6°C (78°F) HI threshold | 26.7°C (80°F) HI threshold | 27.8°C (82°F) HI threshold | 28.9°C (84°F) HI threshold | 30°C (86°F) HI threshold |
|---|---|---|---|---|---|---|---|---|---|---|
| Heat illness | 35 | 6.31 (2.38, 16.68)a | 4.27 (1.94, 9.39)a | 3.77 (1.83, 7.78)a | 4.93 (2.39, 10.18)a | 6.80 (3.17, 14.56)a | 5.69 (2.23, 14.55)a | 2.86 (0.70, 11.77) | 9.61 (1.26, 73.47)a | — |
| Asthma | 2,911 | 0.98 (0.90, 1.06) | 1.02 (0.94, 1.12) | 0.98 (0.89, 1.08) | 1.05 (0.95, 1.17) | 1.04 (0.91, 1.18) | 1.10 (0.93, 1.30) | 1.10 (0.87, 1.39) | 0.91 (0.60, 1.39) | 0.74 (0.23, 2.40) |
| COPD | 2,158 | 0.87 (0.79, 0.96)a | 0.89 (0.81, 0.99)a | 0.87 (0.78, 0.98)a | 0.85 (0.74, 0.97)a | 0.79 (0.67, 0.94)a | 0.76 (0.60, 0.96)a | 0.82 (0.59, 1.15) | 0.73 (0.40, 1.31) | 0.64 (0.15, 2.67) |
| Pneumonia | 2,081 | 0.91 (0.82, 1.00) | 0.89 (0.80, 0.99)a | 0.90 (0.80, 1.01) | 1.00 (0.87, 1.14) | 1.15 (0.98, 1.34) | 1.28 (1.04, 1.57)a | 1.25 (0.93, 1.67) | 0.96 (0.56, 1.64) | 1.06 (0.38, 2.95) |
| Bronchitis | 1,972 | 0.78 (0.71, 0.87)a | 0.84 (0.76, 0.94)a | 0.78 (0.68, 0.88)a | 0.79 (0.69, 0.92)a | 0.81 (0.68, 0.96)a | 0.86 (0.68, 1.10) | 0.78 (0.55, 1.11) | 0.54 (0.28, 1.07) | 0.91 (0.33, 2.50) |
| Arrhythmia | 1,617 | 1.05 (0.94, 1.17) | 1.01 (0.90, 1.14) | 0.98 (0.86, 1.12) | 0.96 (0.83, 1.12) | 0.95 (0.79, 1.14) | 0.87 (0.67, 1.12) | 0.86 (0.60, 1.22) | 0.80 (0.43, 1.48) | 1.05 (0.32, 3.41) |
| Cerebrovascular | 434 | 1.01 (0.82, 1.26) | 0.97 (0.78, 1.22) | 1.05 (0.82, 1.34) | 1.02 (0.77, 1.35) | 0.92 (0.65, 1.32) | 0.80 (0.49, 1.32) | 0.50 (0.22, 1.16) | 0.80 (0.24, 2.58) | 0.79 (0.10, 6.01)b |
| Ischemia | 200 | 1.41 (1.04, 1.92)a | 1.48 (1.08, 2.03)a | 1.29 (0.91, 1.83) | 1.22 (0.82, 1.82) | 1.03 (0.62, 1.69) | 1.08 (0.55, 2.10) | 0.94 (0.36, 2.50) | 0.64 (0.08, 4.85)b | — |
| Myocardial infarction | 81 | 2.00 (1.24, 3.23)a | 2.13 (1.29, 3.49)a | 2.11 (1.24, 3.61)a | 1.50 (0.79, 2.85) | 1.23 (0.53, 2.86) | 1.62 (0.51, 5.07) | 1.37 (0.29, 6.37) | — | — |
| Heart failure | 441 | 0.84 (0.68, 1.04) | 0.85 (0.68, 1.07) | 0.83 (0.64, 1.06) | 0.90 (0.68, 1.20) | 0.96 (0.68, 1.36) | 0.76 (0.46, 1.28) | 0.92 (0.47, 1.81) | 0.29 (0.04, 2.14)b | 1.28 (0.16, 10.09)b |
Note: Conditional logistic regression models adjusted for daily concentration were used to estimate ORs. —, no data; CI; confidence interval; COPD, chronic obstructive pulmonary disease; ED, emergency department; HI, heat index; OR, odds ratio.
95% CI does not include the null.
Only one ED visit related to the indicated health outcome occurred 2 d after an exposure (i.e., a day during which the HI exceeded the indicated threshold) during the study period.