CRP and infection: To examine potential bias due to misclassification of infection, four sensitivity analyses were made: (1) Because the patient group without infiltrate and no bacteraemia may have included people with chronic pulmonary disease who had pneumococci cultured in the absence of any acute infection due to closer surveillance, we repeated our analyses with restriction to patients who all had CRP >100mg/L or leukocytes >10*109/L together with at least one new or increased pulmonary symptom.