Background
Methods
Study design and setting
Selection of participants
Biomarker measurement
Outcomes
Statistical analysis
Results
Patient population
All patients (n = 458) | |
---|---|
Demographics | |
Age (years) – median [IQR] | 45 (32–62) |
Female gender – n (%) | 273 (59.6 %) |
Comorbidities | |
Presence of any comorbidity – n (%) | 70 (15.3 %) |
Finale diagnosis | |
Upper RTI | 184 (40.2 %) |
Acute rhinosinusitis – n (%) | 104 (22.7 %) |
Acute pharyngitis/tonsillitis – n (%) | 75 (16.4 %) |
Acute otitis media – n (%) | 5 (1.1 %) |
Lower non-pneumonic RTI | 205 (44.8 %) |
Common cold – n (%) | 31 (6.8 %) |
Acute bronchitis – n (%) | 140 (30.6 %) |
Influenza – n (%) | 4 (0.9 %) |
Exacerbated COPD – n (%) | 21 (4.6 %) |
Exacerbated asthma – n (%) | 9 (2 %) |
Lower pneumonic RTI | 69 (15.1 %) |
Medical outcome of patients | |
Days with restricted activities within 14 days – median [IQR] | 9 (6–12) |
Persisting discomfort after 14 days | 208 (45.7 %) |
Degree of discomfort (scale 1–10) – median [IQR] | 2 (1–5) |
Biomarkers | |
CRP mg/dL median (SD) [IQR] | 31 (60) (8.3-72.7) |
PCT μg/L median (SD) [IQR] | 0.08 (2.11) (0.05-0.11) |
Correlation between PCT and CRP in different ARIs
Baseline | Overall (n = 450) | ||||
---|---|---|---|---|---|
CRP < 20 | CRP 20-50 | CRP 50-100 | CRP > 100 | Total | |
PCT <0.1 | 141 | 82 | 62 | 15 | 300 |
47 % | 27.3 % | 20.7 % | 5 % | 100 % | |
PCT0.1-0.25 | 38 | 34 | 25 | 33 | 130 |
29.2 % | 26.2 % | 19.2 % | 25.4 % | 100 % | |
PCT 0.25-0.5 | 0 | 1 | 1 | 3 | 5 |
0 % | 20 % | 20 % | 60 % | 100 % | |
PCT > 0.5 | 1 | 0 | 0 | 14 | 15 |
6.7 % | 0 % | 0 % | 93.3 % | 100 % | |
Total | 180 | 117 | 88 | 65 | 450 |
40 % | 26 % | 19.6 % | 14.4 % | 100 % | |
Day 7 | Overall (n = 434) | ||||
CRP < 20 | CRP 20-50 | CRP 50-100 | CRP > 100 | Total | |
PCT <0.1 | 322 | 30 | 5 | 3 | 360 |
89.4 % | 8.3 % | 1.4 % | 0.8 % | 100 % | |
PCT0.1-0.25 | 52 | 7 | 6 | 3 | 68 |
76.5 % | 10.3 % | 8.8 % | 4.4 % | 100 % | |
PCT 0.25-0.5 | 2 | 1 | 0 | 0 | 3 |
66.7 % | 33.3 % | 0 % | 0 % | 100 % | |
PCT > 0.5 | 1 | 0 | 1 | 1 | 3 |
33.3 % | 0 % | 33.3 % | 33.3 % | 100 % | |
Total | 377 | 38 | 12 | 7 | 434 |
86.9 % | 8.8 % | 2.8 % | 1.6 % | 100 % |
Kinetics | Overall (n = 428) | |||||
---|---|---|---|---|---|---|
Increase (CRP) | Decrease (CRP) 0 - 25 % | Decrease (CRP) 25 - 50 % | Decrease (CRP) 50-75 % | Decrease (CRP) > 75 % | Total | |
Increase (PCT) | 22 | 14 | 17 | 26 | 53 | 132 |
16.7 % | 10.6 % | 12.9 % | 19.7 % | 40.2 % | 100 % | |
Decrease (PCT) 0–25 % | 8 | 6 | 9 | 10 | 51 | 84 |
9.5 % | 7.1 % | 10.7 % | 11.9 % | 60.7 % | 100 % | |
Decrease (PCT) 25-50 % | 6 | 5 | 7 | 17 | 60 | 95 |
6.3 % | 5.3 % | 7.4 % | 17.9 % | 63.2 % | 100 % | |
Decrease (PCT) 50–75 % | 2 | 2 | 5 | 9 | 66 | 84 |
2.4 % | 2.4 % | 6 % | 10.7 % | 78.6 % | 100 % | |
Decrease (PCT) > 75 % | 1 | 0 | 1 | 4 | 27 | 33 |
3 % | 0 % | 3 % | 12.1 % | 81.8 % | 100 % | |
Total | 39 | 27 | 39 | 66 | 257 | 428 |
9.1 % | 6.3 % | 9.1 % | 15.4 % | 60.1 % | 100 % |
Association of admission biomarker levels and adverse outcome
Days with restricted activites: coefficient (95 % CI) | ||||||
---|---|---|---|---|---|---|
Demographic-adjusted model
|
Fully adjusted model
a
|
Demographic-adjusted model
|
Adjusted
a
| |||
Biomarker at baseline | CRP (mg/dL) | 0.4 (−0.2 to 0.9), p = 0.169 | 0.3 (−0.3 to 0.9), p = 0.324 | Biomarker on day 7 | 0.7 (0.1 to 1.4), p = 0.035 | 0.6 (−0.1 to 1.3), p = 0.075 |
CRP ≤20 | Reference group | Reference group | Reference group | Reference group | ||
CRP 20-50 | 0.4 (−0.5 to 1.3), p = 0.37 | 0.4 (−0.5 to 1.3), p = 0.407 | 0.7 (−0.6 to 2.0), p = 0.264 | 0.8 (−0.5 to 2.1), p = 0.252 | ||
CRP 50-100 | 0.0 (−1.0 to 1.0), p = 0.956 | −0.1 (−1.0 to 0.9), p = 0.920 | 2.5 (0.3 to 4.7), p = 0.024 | 2.4 (0.2 to 4.5), p = 0.035 | ||
CRP >100 | 1.6 (0.5 to 2.6), p = 0.005 | 1.4 (0.3 to 2.5), p = 0.014 | 3.3 (0.5 to 6.2), p = 0.022 | 2.7 (−0.3 to 5.7), p = 0.078 | ||
PCT (μg/L) | 0.9 (0 to 1.9), p = 0.048 | 0.8 (−0.2 to 1.8), p = 0.123 | 0.7 (−0.6 to 2.1), p = 0.297 | 0.5 (−0.9 to 1.9), p = 0.484 | ||
PCT ≤0.1 | Reference group | Reference group | Reference group | Reference group | ||
PCT 0.1-0.25 | 0.4 (−0.4 to 1.2), p = 0.320 | 0.3 (−0.5 to 1.1), p = 0.407 | 0.6 (−0.4 to 1.6), p = 0.249 | 0.5 (−0.5 to 1.5), p = 0.353 | ||
PCT 0.25-0.5 | 1.6 (−1.3 to 4.4), p = 0.288 | 1.2 (−1.8 to 4.1), p = 0.434 | 2.9 (−1.5 to 7.3), p = 0.194 | 2.3 (−2.1 to 6.7), p = 0.300 | ||
PCT >0.5 | 2.0 (0.0 to 4.0), p = 0.045 | 1.8 (−0.3 to 3.8), p = 0.089 | −0.3 (−4.6 to 4.1), p = 0.900 | −0.7 (−5.1 to 3.7), p = 0.751 | ||
Persistence of discomfort after 14 days: coefficient (95 % CI) | ||||||
Demographic-adjusted model
|
Adjusted
a
|
Demographic-adjusted model
|
Adjusted
a
| |||
Biomarker at baseline | CRP (mg/dL) | 1.0 (0.8 to 1.4), p = 0.831 | 1.0 (0.8 to 1.4), p = 0.828 | Biomarker on day 7 | 1.7 (1.2 to 2.4), p = 0.005 | 1.7 (1.2 to 2.5), p = 0.005 |
CRP ≤20 | Reference group | Reference group | Reference group | Reference group | ||
CRP 20-50 | 1.2 (0.7 to 1.9), p = 0.517 | 1.2 (0.7 to 2), p = 0.436 | 1.6 (0.8 to 3.2), p = 0.203 | 1.7 (0.8 to 3.4), p = 0.166 | ||
CRP 50-100 | 1.0 (0.6 to 1.8), p = 0.862 | 1.1 (0.6 to 1.8), p = 0.828 | 3.4 (0.9 to 13.1), p = 0.078 | 3.4 (0.8 to 13.5), p = 0.085 | ||
CRP >100 | 1.2 (0.7 to 2.2), p = 0.477 | 1.2 (0.7 to 2.3), p = 0.514 | 6.4 (0.7 to 54.8), p = 0.091 | 4.5 (0.5 to 40.9), p = 0.18 | ||
PCT (μg/L) | 1.1 (0.6 to 1.7), p = 0.845 | 1.0 (0.6 to 1.7), p = 0.939 | 0.9 (0.4 to 1.9), p = 0.804 | 0.8 (0.4 to 1.7), p = 0.588 | ||
PCT ≤0.1 | Reference group | Reference group | Reference group | Reference group | ||
PCT 0.1-0.25 | 0.8 (0.5 to 1.3), p = 0.439 | 0.8 (0.5 to 1.3), p = 0.466 | 1.1 (0.7 to 1.9), p = 0.655 | 1.1 (0.6 to 1.9), p = 0.738 | ||
PCT 0.25-0.5 | 3.3 (0.6 to 18.0), p = 0.166 | 2.9 (0.5 to 16.3), p = 0.229 | 2.5 (0.2 to 28.5), p = 0.460 | 1.8 (0.2 to 21.4), p = 0.63 | ||
PCT >0.5 | 1.6 (0.5 to 4.7), p = 0.402 | 1.5 (0.5 to 4.5), p = 0.486 | 0.5 (0.0 to 5.7), p = 0.540 | 0.3 (0.0 to 4.6), p = 0.42 |