Table 2.
Weather conditions on high-fall days in EDs compared with control days, Philadelphia, Pennsylvania, 2006-2011a
| Days With the Weather Condition, No. (%) | ||||
|---|---|---|---|---|
| Weather Conditions | High-Fall Days | Control Days | OR (95% CI) | aOR (95% CI)b |
| Total days | 15 (100.0) | 243 (100.0) | ||
| Temperature | ||||
| Maximum, <33°F | 7 (46.7) | 37 (15.2) | 3.0 (1.1-7.9) | 0.9 (0.2-4.4) |
| Minimum, <24°F | 6 (40.0) | 56 (23.0) | 2.2 (0.7-7.3) | 1.2 (0.2-7.0) |
| Average, <30°F | 7 (46.7) | 50 (20.6) | 3.4 (1.2-9.8) | 4.8 (0.1-185.3) |
| Snow | 12 (80.0) | 37 (15.2) | 22.3 (6.7-73.9) | 13.4 (2.9-61.5) |
| Rain | 8 (53.3) | 68 (28.0) | 2.9 (1.2-7.5) | 7.1 (0.6-87.4) |
| Fog | 6 (40.0) | 27 (11.1) | 5.3 (1.8-16.2) | 2.3 (0.6-8.9) |
Abbreviations: aOR, adjusted odds ratio; ED, emergency department; OR, odds ratio.
aUnpublished patient registration data from 21 hospital EDs throughout the Philadelphia area, collected as part of routine public health syndromic surveillance; limited to the months of December, January, February, and March. High-fall days were defined as days when the number of ED visits for falls exceeded the median number of ED visits for falls per day during the study period plus 3 SDs. Matched control days consisted of the same days of the week (eg, Monday, Tuesday) as the high-fall days from the same winter (16 to 17 control days per high-fall day).
bAdjusted for temperature categories and presence of snow, rain, or fog.