Table 3. Stability of the frequent-exacerbation phenotype over time.
|
Number of exacerbations in the following year |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | ⩾1 | Total | Risk (%) | RDb | 95% CI | Se (%) | Sp (%) | PV+ (%) | PV− (%) | |
| N=345 | N=555 | N=900 | ||||||||
|
Frequent exacerbations in the previous year | ||||||||||
| Infrequent exacerbations ⩽1) | 296 | 267 | 563 | 47.42 | ||||||
| Frequent exacerbations (⩾2) | 49 | 288 | 337 | 85.46 | 38.04 | 32.45–43.62 | 51.89 | 85.8 | 85.46 | 52.58 |
| ⩽1 (IE) | ⩾2 (FE) | Total | Risk (%) | RD | 95% CI | Se (%) | Sp (%) | PV+ (%) | PV- (%) | |
| N=568 | N=332 | N=900 | ||||||||
|
Frequent exacerbations in the previous year | ||||||||||
| Infrequent exacerbations (⩽1) | 438 | 125 | 563 | 22.2 | ||||||
| Frequent exacerbations (⩾2) | 130 | 207 | 337 | 61.42 | 39.22 | 32.99–45.45 | 62.35 | 77.11 | 61.42 | 77.8 |
Abbreviations: CI, confidence interval; FE, frequent exacerbations in the following year; IE, infrequent exacerbations in the following year; PV(+), positive predictive values; PV(−), negative predictive values; RD, risk difference with its 95% CI; Se, sensitivity; Sp, specificity.