| n | Incidence in index group, per 1000 py (95% CI) | Incidence in reference group*, per 1000 py (95% CI) | HR (95% CI) | |
| Sociodemographic factors | ||||
| Male | 199 | 128.5 (98.4 to 158.6) | 79.2 (63.9 to 94.5) | 1.55 (1.14 to 2.10) |
| Institutionalised† | 104 | 153.0 (105.0 to 201.1) | 84.3 (70.0 to 98.5) | 1.73 (1.21 to 2.48) |
| Minimum income | 93 | 92.8 (57.8 to 127.8) | 93.4 (78.1 to 108.7) | 1.00 (0.66 to 1.50) |
| Only primary school | 380 | 101.6 (83.3 to 120.0) | 79.6 (58.3 to 100.8) | 1.27 (0.92 to 1.76) |
| Smoking, current or previous | 278 | 133.0 (107.5 to 158.6) | 63.5 (48.2 to 78.9) | 2.00 (1.47 to 2.73) |
| No yearly influenza vaccine <85 y | 133 | 79.3 (52.6 to 105.9) | 97.1 (80.4 to 113.8) | 0.82 (0.56 to 1.20) |
| Functioning | ||||
| Severe cognitive impairment, MMSE <19 | 96 | 178.9 (122.0 to 235.7) | 82.7 (68.7 to 96.6) | 2.10 (1.46 to 3.02) |
| Depressive symptoms, GDS-15 >4 | 69 | 126.3 (79.5 to 173.1) | 75.8 (61.5 to 90.2) | 1.61 (1.06 to 2.44) |
| Disability in daily living‡ | 201 | 147.0 (113.8 to 180.3) | 73.9 (59.3 to 88.5) | 1.94 (1.43 to 2.62) |
| Comorbidities and medication use | ||||
| Diabetes mellitus | 85 | 95.6 (56.5 to 134.7) | 93.3 (78.4 to 108.3) | 1.00 (0.65 to 1.56) |
| Hypertension | 226 | 101.5 (77.9 to 125.1) | 89.0 (71.8 to 106.3) | 1.13 (0.84 to 1.53) |
| Myocardial infarct | 62 | 118.0 (64.9 to 171.1) | 91.1 (76.7 to 105.6) | 1.26 (0.78 to 2.03) |
| Stroke | 59 | 206.2 (129.9 to 282.6) | 85.2 (71.3 to 99.0) | 2.26 (1.50 to 3.39) |
| Heart failure | 74 | 115.6 (66.1 to 165.0) | 90.3 (75.9 to 104.8) | 1.23 (0.78 to 1.94) |
| Chronic obstructive pulmonary disease | 69 | 270.6 (184.5 to 356.6) | 79.2 (65.8 to 92.6) | 3.07 (2.13 to 4.41) |
| Cancer | 104 | 110.6 (71.7 to 149.5) | 91.0 (76.1 to 106.0) | 0.86 (0.58 to 1.27) |
| Anaemia§ | 149 | 106.3 (74.5 to 138.0) | 87.2 (71.5 to 102.9) | 1.19 (0.84 to 1.69) |
| Oral glucocorticosteroid use | 11 | 266.3 (69.0 to 463.5) | 91.5 (77.6 to 105.4) | 2.77 (1.30 to 5.89) |
| Creatinine clearance <30 ml/min | 41 | 121.6 (52.8 to 190.4) | 89.5 (75.0 to 104.0) | 1.35 (0.75 to 2.44) |
| Urea >7.5 mmol/l | 233 | 105.3 (80.8 to 129.8) | 83.1 (66.0 to 100.2) | 1.23 (0.90 to 1.68) |
| CRP >5 mg/l | 188 | 138.7 (105.7 to 171.7) | 73.5 (58.7 to 88.4) | 1.82 (1.33 to 2.49) |
| Overall incidence of lower respiratory tract infections | 93.8 (79.8 to 107.7) |
*Definition of reference groups: females, living independently, pension or other extra incomes, additional education after primary school, non-smoking, yearly influenza vaccine, not severely cognitively impaired (MMSE ⩾19), no depressive symptoms (GDS-15 ⩽4), not disabled (see definition), no comorbidity, no oral glucocorticosteroid use, CRP ⩽5 mg/l, creatinine clearance ⩾30 ml/min, urea ⩽7.5 mmol/l.
†Institutionalised refers to nursing or retirement home resident.
‡Disability in daily living = being unable to do any one of the nine basic activities of daily living independently.
§Hbfemale<7.5 mmol/l, Hbmale<8.1 mmol/l.
CRP, C reactive protein; GDS-15, Geriatric Depression Scale with 15 items (only administered to participants with MMSE score ⩾19 (n = 491)); HR, hazard ratio; MMSE, Mini-Mental State Examination; py, person-year.