Risk of dying within 30 days of admission in chronic obstructive pulmonary disease patients according to two follow-up sources
| Mortality register | Hospital discharge register | ||||||
| Patient days | Cases | Rate·1000patient-days−1 | RR (95% CI) | Cases | Rate·1000patient-days−1 | RR (95% CI) | |
| Subjects | 770000 | 925 | 812 | ||||
| Age yrs | |||||||
| 35–54 | 50000 | 6 | 0.12 | 1 | 4 | 0.08 | 1 |
| 55–64 | 110000 | 19 | 0.17 | 1.41 (0.56–3.54) | 16 | 0.14 | 1.79 (0.6–5.35) |
| 65–74 | 250000 | 167 | 0.67 | 5.60 (2.48–12.65) | 149 | 0.60 | 7.50 (2.78–20.25 |
| 75–84 | 250000 | 377 | 1.52 | 12.62 (5.63–28.27) | 345 | 1.39 | 17.33 (6.47–46.43 |
| ≥85 | 110000 | 356 | 3.35 | 27.88 (12.44–62.48) | 298 | 2.79 | 34.84 (12.99–93.43) |
| Sex | |||||||
| Female | 325000 | 366 | 1.13 | 1 | 343 | 0.11 | 1 |
| Male | 445000 | 559 | 1.13 | 1.13 (0.99–1.29) | 469 | 0.11 | 1.01 (0.88–1.16) |
| Place of residence | |||||||
| Outside Rome | 430000 | 435 | 1.01 | 1 | 372 | 0.86 | 1 |
| Rome | 330000 | 490 | 1.46 | 1.45 (1.27–1.65) | 440 | 1.31 | 1.52 (1.32–1.75) |
| Education yrs | |||||||
| >8 | 62000 | 77 | 1.25 | 1 | 77 | 1.25 | 1 |
| 5–8 | 540000 | 628 | 1.17 | 0.93 (0.74–1.18) | 557 | 1.03 | 0.83 (0.65–1.05) |
| <5 | 95000 | 121 | 1.28 | 1.02 (0.77–1.36) | 94 | 0.99 | 0.79 (0.59–1.07) |
| Missing data | 73000 | 99 | |||||
| Admission ward | 925 | ||||||
| Appropriate# | 170000 | 152 | 0.90 | 1 | 123 | 0.72 | 1 |
| Acceptable¶ | 530000 | 673 | 1.27 | 1.43 (1.20–1.70) | 597 | 1.13 | 1.57 (1.29–1.90) |
| Not appropriate | 65000 | 100 | 1.54 | 1.73 (1.34–2.22) | 92 | 1.41 | 1.97 (1.50–2.58) |
| Follow-up time days | |||||||
| 0–6 | 160000 | 315 | 2.03 | 1 | 318 | 2.05 | 1 |
| 7–13 | 180000 | 228 | 1.27 | 0.63 (0.53–0.74) | 210 | 1.17 | 0.57 (0.48–0.68) |
| 14–20 | 180000 | 179 | 1.01 | 0.50 (0.41–0.60) | 145 | 0.81 | 0.40 (0.33–0.48) |
| 21–30 | 250000 | 203 | 0.80 | 0.40 (0.33–0.47) | 139 | 0.55 | 0.26 (0.22–0.33) |
| Comorbidities+ | |||||||
| 0 | 490000 | 468 | 1.00 | 1 | 420 | 0.85 | 1 |
| 1 | 140000 | 170 | 1.26 | 1.32 (1.11–1.57) | 152 | 1.12 | 1.32 (1.09–1.58) |
| 2 | 100000 | 183 | 1.84 | 1.93 (1.62–2.29) | 153 | 1.53 | 1.79 (1.49–2.16) |
| ≥3 | 39000 | 104 | 2.68 | 2.81 (2.27–3.47) | 87 | 2.23 | 2.61 (2.07–3.29) |
| Hospitalisation in the last 2 yrs | |||||||
| 0 | 400000 | 441 | 1.10 | 1 | 408 | 1.01 | 1 |
| 1 | 185000 | 220 | 1.23 | 1.12 (0.95–1.32) | 188 | 1.05 | 1.03 (0.87–1.23) |
| 2 | 185000 | 264 | 1.44 | 1.32 (1.13–1.54) | 216 | 1.18 | 1.16 (0.99–1.37) |
| Hospitalisation in the last 2 yrs with respiratory failure | |||||||
| 0 | 730000 | 854 | 1.17 | 1 | 752 | 1.03 | 1 |
| 1 | 29000 | 42 | 1.44 | 1.23 (0.9–1.67) | 35 | 1.20 | 1.16 (0.83–1.63) |
| 2 | 8500 | 29 | 3.39 | 2.89 (2.00–4.18) | 25 | 2.90 | 2.81 (1.89–4.19) |
Data are presented as n, unless otherwise stated. RR: rate ratio; CI: confidence interval. #: pneumology and intensive care unit; ¶: general medicine, geriatrics, causality ward; +: respiratory failure, lung cancer, pneumoconiosis, other cancer, heart failure, arrhythmias, other heart and vascular diseases excluding acute myocardial infarction, chronic kidney failure, central nervous system diseases, traumas and poisonings during previous hospitalisation.