Characteristics of cases included in the analysis by survival interval
| Years from spirometric testing to death | ||||
|---|---|---|---|---|
| <10 | 10–14 | 15–19 | Total (%) | |
| No of cases matched to control with spirogram | 48 | 50 | 45 | 143 (100%) |
| Age at entry (years) | ||||
| 40–44 | 1 | 1 | 0 | 2 (1%) |
| 45–49 | 2 | 5 | 4 | 11 (8%) |
| 50–54 | 2 | 6 | 9 | 17 (12%) |
| 55–59 | 14 | 13 | 13 | 40 (28%) |
| 60–64 | 15 | 20 | 13 | 48 (34%) |
| 65–69 | 11 | 2 | 6 | 19 (13%) |
| 70–74 | 3 | 3 | 0 | 6 (4%) |
| Smoking at entry | ||||
| Never smoked | 3 | 0 | 2 | 5 (4%) |
| Former smoker | 10 | 13 | 14 | 37 (26%) |
| Pipe or cigar | 0 | 0 | 1 | 1 (1%) |
| Cigarettes <20/day | 11 | 16 | 16 | 43 (30%) |
| Cigarettes 20/day | 10 | 5 | 2 | 17 (12%) |
| Cigarettes >20/day | 8 | 10 | 7 | 25 (17%) |
| Hand rolled cigarettes | 5 | 6 | 3 | 14 (10%) |
| Coded underlying cause of death | ||||
| Chronic bronchitis (ICD8 491) | 41 | 33 | 13 | 87 (61%) |
| Emphysema (ICD8 492) | 6 | 5 | 6 | 17 (12%) |
| Chronic airways obstruction (ICD8 519.8) | 1 | 12 | 26 | 39 (27%) |