we have no information on the exact duration of illness.
As this is likely to have an impact on CRP levels,
interpretations of CRP as a single variable should be
treated with caution. This limitation does not, however,
devalue the main finding ‘‘degree of suspicion’’ in
relation to CXR.
Another limitation is that the degree of suspicion was
rated only after the CRP results, but not before. Thus we
do not know to what extent the CRP result affected the
degree of suspicion. On the other hand the fact that PPV
for CRP50 mg/L was much lower than PPV for the
term ‘‘sure’’ might indicate that clinical examination
adds important complementary information