Background
Methods
Study design and patient population
Measurement of biomarkers
The detection of CAP pathogen
Statistical analysis and data management
Outcomes
Results
Demographics and clinical presentations
All patients (%) n=350 | Survivors (%) n=312 | Non-Survivors (%) n=38 | P value | |
---|---|---|---|---|
Age(years) | 58.53±19.1 | 58.59±19.2 | 58.03±18.9 | 0.86 |
Males | 204 (58.3) | 181(58.0) | 23(60.5) | 0.7 |
Comorbidity | ||||
Diabetes Mellitus | 30(8.57) | 27(8.6) | 3(7.8) | 0.87 |
Chronic heart disease | 100(28.57) | 91(29.1) | 9(23.6) | 0.48 |
Chronic liver disease | 22(6.29) | 20(6.4) | 2(5.2) | 0.78 |
Chronic renal disease | 47(13.43) | 40(12.8) | 7(18.4) | 0.34 |
Malignant disease | 26(7.43) | 24(7.6) | 2(5.2) | 0.59 |
History of Shock | 17(4.86) | 15(4.8) | 2(5.2) | 0.9 |
COPD | 22(6.29) | 18(5.7) | 4(10.5) | 0.25 |
Cerebrovascular disease | 39(11.14) | 35(11.2) | 4(10.5) | 0.9 |
Antimicrobial treatment before admission | 79(22.6) | 70(22.4) | 9(23.7) | 1 |
Signs and symptoms | ||||
Cough | 268(76.6) | 260(83.3) | 28(73.6) | 0.14 |
Chest pain | 116(33.1) | 106(33.9) | 10(26.3) | 0.34 |
Expectoration | 168(48) | 148(47.4) | 20(52.6) | 0.54 |
Dyspnea | 249(71.1) | 221(70.8) | 28(73.6) | 0.72 |
Chills | 124(35.4) | 109(34.9) | 15(39.4) | 0.58 |
Headaches | 75(21.4) | 58(18.5) | 17(44.7) |
<0.001
|
Myalgia | 79(22.6) | 71(22.7) | 8(21) | 0.8 |
Crackles | 114(32.6) | 102(32.6) | 12(31.5) | 0.89 |
Fever | 110(31.4) | 96(30.7) | 14(36.8) | 0.45 |
Confusion | 5(1.4) | 1(0.3) | 4(10.5) |
<0.001
|
CCI class | ||||
0-2 | 129(36.8) | 116(37.1) | 13(34.2) | 0.7 |
3-5 | 180(51.4) | 161(51.6) | 19(50) | |
>5 | 41(11.7) | 35(11.2) | 6(15.7) | |
CRP1 (mg/L) | 65.3±84.7 | 66.3±85.2 | 57.1±81.3 | 0.53 |
CRP3 (mg/L) | 56.4±77.4 | 50±66.4 | 109.1±128.4 |
<0.001
|
CRP3c | 556.6±5056.3 | 575.2±5334.2 | 401.2±1242.4 | 0.843 |
CRP3c<0 | 223(63.7) | 214(68.5) | 9(23.6) |
<0.001
|
CRP5(mg/L) | 44.8±68.5 | 37.9±61 | 102.1±96.9 |
<0.001
|
CRP5c | 429.2±3489.6 | 429.2±3670.1 | 429.3±1207.6 | 0.999 |
CRP5c<0 | 222(63.4) | 213(68.2) | 9(23.6) |
<0.001
|
PCT1 (ng/mL) | 1.8±7.1 | 1.8±7.3 | 1.9±5.5 | 0.96 |
PCT3 (ng/mL) | 1.7±6.3 | 1.4±4.4 | 4.1±14.5 |
0.012
|
PCT3c | 791.2±2653.8 | 793.3±2672.6 | 774.1±2528.7 | 0.966 |
PCT3c<0 | 174(49.7) | 157(50.3) | 17(44.7) | 0.52 |
PCT5 (ng/mL) | 1.2±3.7 | 0.8±2 | 4.3±9.3 |
<0.001
|
PCT5c | 695.3±2463 | 589.9±2298.2 | 1555±3454.4 |
0.022
|
PCT5c<0 | 179(51.1) | 170(54.4) | 9(23.6) |
<0.001
|
WBC1 | 10.4±8 | 10.1±7.2 | 12.6±12.8 | 0.081 |
WBC3 | 9.5±5 | 9.2±5 | 10.8±4.7 | 0.112 |
WBC5 | 10.5±6.6 | 10.4±7 | 10.6±4.7 | 0.932 |
CURB class | ||||
0-2 | 289 | 256 | 33 | 0.46 |
3-5 | 61 | 56 | 5 |
Statistic analysis for clinical factors and CAP
Univariate analysis | Multivariate analysis | |||||
---|---|---|---|---|---|---|
Odds ratio (95% CI) | Estimate | Univariate P-value | Odds ratio (95% CI) | Estimate | Multivariate P-value | |
CRP1 (mg/L) | 0.998(0.994–1.003) | −0.001 | 0.53 | |||
CRP3 (mg/L) | 1.006(1.003–1.01) | 0.006 | < 0.001 | 1.013 (1–1.025) | 0.012 | 0.002 |
CRP3c | 0.999(0.999–1) | 0 | 0.845 | |||
CRP3c < 0 | 1.02(0.991–1.049) | 0.019 | 0.174 | |||
CRP5(mg/L) | 1.008(1.004–1.01) | 0.008 | < 0.001 | 1.011 (1–1.021) | 0.011 | 0.028 |
CRP5c | 1(0.999–1) | 0 | 0.999 | |||
PCT1 (ng/mL) | 1.001(0.955–1.05) | 0.001 | 0.96 | |||
PCT3 (ng/mL) | 1.036(0.998–1.07) | 0.035 | 0.06 | |||
PCT3c | 0.999(0.999–1) | 0 | 0.966 | |||
PCT5 (ng/mL) | 1.21(1.08–1.357) | 0.191 | < 0.001 | 1.277 (1.004–1.624) | 0.244 | 0.046 |
PCT5c | 1(0.999–1) | 0 | 0.052 | |||
WBC1 | 1.025(0.993–1.059) | 0.025 | 0.117 | |||
WBC3 | 1.061(0.985–1.143) | 0.059 | 0.118 | |||
WBC5 | 1.004(0.906–1.113) | 0.004 | 0.931 |
Initial treatment failure | Univariate Odds ratio(95% CI) | Univariate P-value | Multivariate Odds ratio(95% CI) | Multivariate P-value | ||
---|---|---|---|---|---|---|
Yes | No | |||||
CRP1 (mg/L) |
71±88.7
|
64±83.9
|
0.999(0.996-1.003)
|
0.55
|
1.008(1.001-1.013)
|
0.009
|
CRP3 (mg/L) |
89.2±107.6
|
48.9±66.8
|
0.995(0.991-0.998)
|
0.001
|
0.992(0.985-0.999)
|
0.035
|
CRP3c | 801.8±3644.9 | 501±5328.5 | 1 | 0.673 | 1(0.999-1) | 0.33 |
CRP5(mg/L) | 79.7±96.3 | 37.2±58.3 | 0.993(0.989-0.997) | <0.001 | 0.996(0.989-1.001) | 0.15 |
CRP5c | 682.9±2888.4 | 371.7±3614.2 | 1 | 0.534 | 1(0.999-1) | 0.299 |
PCT1 (ng/mL) | 4.6±13.6 | 1.2±4.2 | 0.936(0.892-0.983) | 0.009 | 0.89(0.82-0.965) |
0.005
|
PCT3 (ng/mL) |
2.8±11.2
|
1.4±4.5
|
0.975(0.941-1.01)
|
0.163
|
1.134(1.017-1.263)
|
0.022
|
PCT3c | 469.1±1972.7 | 865.2±2784.4 | 1 | 0.293 | 1(0.999-1) | 0.403 |
PCT5 (ng/mL) |
2.8±7.3
|
0.8±2.1
|
0.868(0.892-0.983)
|
0.005
|
0.851(0.751-0.963)
|
0.01
|
PCT5c | 1013.8±2761.2 | 622.1±2388.7 | 1 | 0.268 | 1(0.999-1) | 0.658 |
Correlation between PCT and CRP and their clearance
PCT1(ng/ml) | PCT3(ng/ml) | PCT5(ng/ml) | PCT3c | PCT5c | |
---|---|---|---|---|---|
CRP1 (mg/L) | R2=0.35 P=0.0001* | ||||
CRP3 (mg/L) | R2=0.19 P=0.0001* | ||||
CRP3c | R2=0.09 P=0.11 | ||||
CRP5(mg/L) | R2=0.21, P=0.0001* | ||||
CRP5c | R2=0.17 P=0.002* |
Prognostic accuracy of serial values of PCT and CRP
Variable(s) | AUC | SE | P value | 95%CI |
---|---|---|---|---|
CRP1 (mg/L) | 0.45 | 0.05 | 0.37 | 0.36-0.55 |
CRP3 (mg/L) | 0.69 | 0.05 | <0.001 | 0.6-0.8 |
CRP3c | 0.77 | 0.04 | <0.001 | 0.7-0.85 |
CRP5(mg/L) | 0.76 | 0.05 | <0.001 | 0.67-0.85 |
CRP5c | 0.81 | 0.03 | <0.001 | 0.75-0.87 |
PCT1 (ng/mL) | 0.57 | 0.05 | 0.11 | 0.49-0.67 |
PCT3 (ng/mL) | 0.61 | 0.05 | 0.02 | 0.52-0.71 |
PCT3c | 0.57 | 0.04 | 0.13 | 0.49-0.66 |
PCT5 (ng/mL) | 0.73 | 0.04 | <0.001 | 0.65-0.82 |
PCT5c | 0.65 | 0.05 | <0.001 | 0.57-0.75 |
CRP1*PCT1 | 0.55 | 0.05 | 0.36 | 0.45-0.65 |
CRP3*CRP3c | 0.7 | 0.05 | <0.001 | 0.6-0.8 |
CRP5*CRP5c | 0.77 | 0.05 | <0.001 | 0.68-0.86 |
PCT3*PCT3c | 0.65 | 0.04 | <0.001 | 0.56-0.74 |
PCT5*PCT5c | 0.74 | 0.04 | <0.001 | 0.66-0.83 |
CRP3*PCT3 | 0.7 | 0.05 | <0.001 | 0.6-0.81 |
CRP3c*PCT3c | 0.76 | 0.04 | <0.001 | 0.68-0.84 |
CRP5*PCT5 | 0.79 | 0.04 | <0.001 | 0.71-0.87 |
CRP5c*PCT5c | 0.67 | 0.04 | <0.001 | 0.58-0.76 |
CRP5*CRP5c*PCT5*PCT5c | 0.79 | 0.04 | <0.001 | 0.71-0.87 |
CRP3*CRP3c* CRP5*CRP5c | 0.85 | 0.04 | <0.001 | 0.77-0.92 |
PCT3*PCT3c*PCT5*PCT5c | 0.81 | 0.04 | <0.001 | 0.73-0.9 |
CRP3*CRP3c* CRP5*CRP5c* PCT3*PCT3c*PCT5*PCT5c | 0.81 | 0.04 | <0.001 | 0.73-0.88 |
CURB-65 | 0.53 | 0.05 | 0.53 | 0.44-0.63 |
CRP3*CRP3c*CRP5*CRP5c*CURB-65 | 0.77 | 0.04 | <0.001 | 0.69-0.85 |
PCT3*PCT3c*PCT5*PCT5c*CURB-65 | 0.72 | 0.05 | <0.001 | 0.64-0.81 |