Table 1.
Frequency of visits for each ICD code by heat waves and control periods in San Diego County, 2012–2016
| ICD-9 primary code | Heat wave 1, 3 days (6 control days) | Heat wave 2, 2 days (4 control days) | Heat wave 3, 2 days (4 control days) | Heat wave 4, 7 days (14 control days) | Heat wave 5, 3 days (6 control days) | Heat wave 6, 4 days (8 control days) | Combined, 21 days (42 control days) |
|---|---|---|---|---|---|---|---|
| Diabetes | |||||||
| Heat wave | 0 | 0 | 3 | 13 | 7 | 6 | 29 |
| Control perioda | 4 | 2 | 8 | 21 | 8 | 16 | 59 |
| Fluid and electrolyte disorders | |||||||
| Heat wave | 0 | 0 | 0 | 0 | 0 | 2 | 2 |
| Control period | 0 | 0 | 0 | 1 | 2 | 1 | 4 |
| Cardiovascular disease | |||||||
| Heat wave | 2 | 1 | 4 | 15 | 1 | 6 | 29 |
| Control period | 3 | 0 | 7 | 27 | 6 | 5 | 48 |
| Respiratory disease | |||||||
| Heat wave | 1 | 1 | 4 | 19 | 4 | 7 | 36 |
| Control period | 2 | 1 | 6 | 16 | 7 | 14 | 46 |
| Renal disease | |||||||
| Heat wave | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
| Control period | 0 | 0 | 1 | 1 | 0 | 1 | 3 |
| UTI | |||||||
| Heat wave | 1 | 1 | 5 | 13 | 5 | 3 | 28 |
| Control period | 1 | 1 | 5 | 38 | 10 | 6 | 61 |
| Combined | |||||||
| Heat wave | 4 | 3 | 16 | 60 | 17 | 27 | 125 |
| Control period | 10 | 4 | 27 | 104 | 33 | 43 | 221 |
Values listed in this table are the frequency of visits for a specific ICD code during a heat wave and its corresponding control period.
aThe control periods chosen were twice the length of the heat periods.