Table 1: Characteristics of study cohort, 1996-2010*.
| Characteristic | Both seasons n = 352 818 |
Cold season† n = 188 415 |
Warm season‡ n = 164 403 |
|---|---|---|---|
| Age, yr, mean (IQR) | 76 (68-86) | 76 (69-86) | 75 (68-86) |
| Male sex | 49.2 | 49.0 | 49.4 |
| Admissions to hospital within 1 yr before death | |||
| Acute myocardial infarction | 8.8 | 8.9 | 8.7 |
| Heart failure | 17.0 | 17.1 | 16.8 |
| Stroke | 10.3 | 10.3 | 10.2 |
| Diabetes | 16.2 | 16.0 | 16.5 |
| Chronic obstructive pulmonary disease | 11.7 | 11.8 | 11.6 |
| Any respiratory illness | 32.6 | 32.9 | 32.3 |
| History of chronic conditions | |||
| Hypertension | 63.5 | 63.5 | 63.6 |
| Acute myocardial infarction | 10.7 | 10.8 | 10.6 |
| Heart failure | 34.5 | 34.9 | 34.1 |
| Chronic obstructive pulmonary disease | 34.8 | 34.9 | 34.8 |
| Diabetes | 28.9 | 28.7 | 29.1 |
| Cause of death | |||
| Nonaccidental | 100.0 | 100.0 | 100.0 |
| Any cardiovascular | 32.6 | 33.2 | 32.0 |
| Coronary heart disease | 18.8 | 19.1 | 18.5 |
| Acute myocardial infarction | 8.2 | 8.4 | 7.9 |
| Heart failure, cardiac arrest and related | 4.8 | 4.8 | 4.7 |
| Stroke | 7.2 | 7.5 | 6.9 |
| Diabetes | 3.6 | 3.6 | 3.6 |
| Any respiratory cause | 8.8 | 9.6 | 7.9 |
| Time period | |||
| 1996-2000 | 27.7 | 28.2 | 27.1 |
| 2001-2005 | 31.2 | 31.0 | 31.3 |
| 2006-2010 | 41.1 | 40.8 | 41.6 |
| Region§ | |||
| North | 3.9 | 3.7 | 4.2 |
| West | 10.5 | 10.7 | 10.4 |
| East | 9.6 | 9.6 | 9.5 |
| Central east | 52.3 | 52.3 | 52.3 |
| Central west | 23.7 | 23.7 | 23.6 |
Note: IQR = interquartile range.
*Values are percentages, unless otherwise specified.
†December to February.
‡June to August.
§Five census divisions were included in the north, 6 in the west, 3 in the east, 7 in the central east and 6 in the central west region.