. 2023 May 24;131(5):057009. doi: 10.1289/EHP11363

Table 10.

ORs and 95% CIs for ED visits on heat wave days vs. non–heat wave days 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	15.26 (4.58, 50.80)^a	10.10 (4.05, 25.24)^a	10.92 (4.67, 25.54)^a	21.02 (8.22, 53.75)^a	21.49 (8.26, 55.92)^a	27.71 (9.65, 79.59)^a	12.35 (3.95, 38.66)^a	11.95 (1.68, 84.81)^a	—
Asthma	2,911	1.03 (0.95, 1.13)	1.03 (0.94, 1.13)	1.04 (0.94, 1.16)	1.03 (0.91, 1.17)	1.05 (0.90, 1.23)	1.04 (0.85, 1.26)	1.20 (0.89, 1.62)	0.71 (0.33, 1.55)	—
COPD	2,158	0.97 (0.88, 1.08)	0.97 (0.86, 1.08)	0.96 (0.84, 1.09)	0.96 (0.82, 1.12)	0.82 (0.66, 1.01)	0.68 (0.51, 0.91)^a	0.60 (0.37, 0.97)^a	1.23 (0.48, 3.13)	—
Pneumonia	2,081	0.91 (0.82, 1.01)	0.89 (0.79, 1.00)	0.91 (0.80, 1.04)	0.97 (0.83, 1.14)	1.20 (0.98, 1.45)	1.20 (0.93, 1.54)	1.37 (0.95, 1.98)	1.11 (0.39, 3.10)	—
Bronchitis	1,972	0.81 (0.72, 0.90)^a	0.82 (0.72, 0.92)^a	0.79 (0.68, 0.91)^a	0.74 (0.62, 0.88)^a	0.73 (0.58, 0.93)^a	0.74 (0.56, 0.99)^a	0.60 (0.36, 0.99)^a	1.35 (0.61, 2.99)	—
Arrhythmia	1,617	1.01 (0.90, 1.13)	1.00 (0.88, 1.14)	0.98 (0.84, 1.13)	0.91 (0.76, 1.09)	0.93 (0.73, 1.17)	0.71 (0.51, 0.99)^a	0.75 (0.45, 1.27)	1.11 (0.39, 3.12)	—
Cerebrovascular	434	1.01 (0.80, 1.27)	1.04 (0.80, 1.33)	1.08 (0.81, 1.44)	1.17 (0.84, 1.63)	1.41 (0.95, 2.09)	1.13 (0.66, 1.93)	1.22 (0.54, 2.74)	0.80 (0.10, 6.21)^b	—
Ischemia	200	1.31 (0.94, 1.83)	1.48 (1.04, 2.10)^a	1.69 (1.16, 2.48)^a	1.73 (1.11, 2.71)^a	1.51 (0.82, 2.77)	1.76 (0.77, 4.00)	1.98 (0.64, 6.14)	—	—
Myocardial infarction	81	2.18 (1.32, 3.60)^a	2.11 (1.22, 3.66)^a	2.24 (1.22, 4.11)^a	2.85 (1.45, 5.60)^a	1.66 (0.52, 5.27)	1.43 (0.26, 7.74)	1.09 (0.10, 11.59)^b	—	—
Heart failure	441	0.79 (0.63, 1.00)^a	0.77 (0.59, 1.00)	0.81 (0.60, 1.09)	0.87 (0.61, 1.24)	0.81 (0.51, 1.30)	0.74 (0.41, 1.34)	0.94 (0.38, 2.35)	1.87 (0.39, 8.90)	—

Note: For the acute heat wave analysis, the results of which are reported in this table, a heat wave day was defined as a day on which the observed HI was above the indicated threshold as was the HI on the previous day. Days with a HI below the threshold and/or those that were preceded by a daily HI below the threshold were considered non–heat wave days. Conditional logistic regression models adjusted for daily $particulate matter begin subscript 2.5 end subscript$ 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.

^{^a}

95% CI does not include the null.

^{^b}

Only one ED visit related to the indicated health outcome occurred on an exposed day (i.e., an acute heat wave day as defined above) during the study period.