Table 1.
Overview of risk factors associated with community-acquired pneumonia and pneumococcal disease
| Risk factor | Cohort studies | Case-control studies | ||
|---|---|---|---|---|
| Number of cohorts* | Risk range† | Number of cohorts* | Risk range† | |
| Community-acquired pneumonia | ||||
| Chronic respiratory diseases | 8‡ | OR: 1.5 HR: 2.9 Rate ratio: 3.8–8.6 |
15§ | OR: 1.3–13.5 RR: 1.6–2.8 HR: 1.2 |
| Current smoking status | 4 | HR: 1.1 Rate ratio: 3.3–4.0 |
6 | OR: 1.0–2.3 HR: 2.0 RR: 1.5 |
| Diabetes mellitus | 7 | HR: 1.0–1.9 Rate ratio: 1.6–3.1 |
9 | OR: 1.0–1.4 HR: 1.1 RR: 1.2–1.3 |
| Chronic heart disease | 6 | HR: 1.5–3.1 Rate ratio: 3.8–4.9 |
17 | OR: 1.0–3.3 HR: 1.3 RR: 1.3–2.6 |
| Pneumococcal pneumonia | ||||
| Chronic respiratory diseases | 6¶ | Rate ratio: 3.7–9.8 | 0 | – |
| Current smoking status | 3 | Rate ratio: 3.0–4.4 | 0 | – |
| Diabetes mellitus | 6 | RR: 2.3 Rate ratio: 1.5–3.1 |
0 | – |
| Chronic heart disease | 3 | Rate ratio: 3.8–5.1 | 0 | – |
| Invasive pneumococcal disease | ||||
| Chronic respiratory diseases | 9** | OR: 2.1–16.8 Rate ratio: 2.5–7.7 |
4†† | OR: 1.3–4.7 |
| Current smoking status | 5 | OR: 2.2 RR: 2.7 Rate ratio: 3.6–4.3 |
1 | OR: 1.1 |
| Diabetes mellitus | 10 | OR: 1.4–4.6 Rate ratio: 1.5–3.9 |
2 | OR: 1.5–1.7 |
| Chronic heart disease | 5 | OR: 3.0–6.9 Rate ratio: 2.9–3.9 |
4 | OR: 1.7–9.9 |
*For studies that only reported data separately for each cohort, all cohorts were included; for studies that reported data for the overall study population, the summary data were used.
†Risk in individuals with factor versus risk in those without risk factor; ranges are based on the lowest and highest values from the publications evaluated using the risk terminology (eg, relative risk or risk ratio) as stated in the original publications.
‡Comprising the following diseases (number of cohorts): asthma (3), bronchitis (0), COPD (1), lung disease (not specified; 4).
§Comprising the following diseases (number of cohorts): asthma (3), bronchitis (1), COPD (5), lung disease (not specified; 6).
¶Comprising the following diseases (number of cohorts): asthma (3), lung disease (not specified; 3).
**Comprising the following diseases (number of cohorts): asthma (4), lung disease (not specified; 5).
††Comprising the following diseases (number of cohorts): asthma (2), COPD (2).
HR, hazard ratio; OR, odds ratio; RR, relative risk.