The added diagnostic value of five different C-reactive protein point-of-care test devices in detecting pneumonia in primary care: A nested case-control study.
BACKGROUND
The results obtained from various point-of-care (POC) test devices for estimating C-reactive protein (CRP) levels in a laboratory setting differ when compared to a laboratory reference test. We aimed to determine whether such differences meaningfully affect the accuracy and added diagnostic value in predicting radiographic pneumonia in adults presenting with acute cough in primary care.


METHODS
A nested case control study of adult patients presenting with acute cough in 12 different European countries (the Genomics to combat Resistance against Antibiotics in Community-acquired LRTI in Europe [GRACE] Network). Venous blood samples from 100 patients with and 100 patients without pneumonia were tested with five different POC CRP tests and a laboratory analyzer. Single test accuracy values and the added value of CRP to symptoms and signs were calculated.


RESULTS
Single test accuracy values showed similar results for all five POC CRP tests and the laboratory analyzer. The area under the curve of the different POC CRP tests and the laboratory analyzer (range 0.79-0.80) were all comparable and higher than the clinical model without CRP (0.70). Multivariable odds ratios were the same (1.2) for all CRP tests.


CONCLUSIONS
Five POC CRP test devices and the laboratory analyzer performed with similar accuracy in detecting pneumonia both as single test, and when used in addition to clinical findings. Variability in results obtained from standard CRP laboratory and POC test devices do not translate into clinically relevant differences when used for prediction of pneumonia in patients with acute cough in primary care.
University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care , Utrecht , the Netherlands.
Margaretha C
MC
Minnaard
Alma C
AC
van de Pol
Joris A H
JA
de Groot
Niek J
NJ
De Wit
Rogier M
RM
Hopstaken
Sanne
S
van Delft
Herman
H
Goossens
Margareta
M
Ieven
Christine
C
Lammens
Paul
P
Little
Chris C
CC
Butler
Berna D L
BD
Broekhuizen
Theo J M
TJ
Verheij
D000328:Adult; D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011014:Pneumonia / Q000097:blood / Q000175:diagnosis*; D000067716:Point-of-Care Testing; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D002097:C-Reactive Protein
C-reactive protein; diagnostic tests; lower respiratory tract infections; point-of-care testing; primary health care