Data published in BMC Infectious Diseases indicated that the diagnostic criteria for community-acquired pneumonia (CAP) within randomized controlled trials (RCTs) are highly heterogeneous, a fact that may have consequences on the validity of trial results.
The study investigators analyzed 47 RCTs related to CAP recorded on ClincalTrials.gov, and as a result of high heterogeneity, they further divided similar CAP inclusion criteria into 8 patterns, based on 42 different CAP inclusion criteria combinations. The diagnostic performances of these CAP definition patterns were then applied to a reference population of 319 suspected cases. The diagnosis was confirmed in 163 cases and excluded in 156 cases by an adjudication committee after a systematic thoracic computed tomography (CT)-scan and a 28-day follow-up period.
The heterogeneity of the inclusion criteria could not be explained by methodology or study objectives. The range of diagnostic performance of the 8 patterns were 9.8–73.0% for sensitivities, 56.4% to 97.4% for specificities, 63.6% to 83.6% for positive predictive values, and 50.8% to 66.7% for negative predictive values. No CAP definition had either sensitivity or specificity higher than 65%. The rate of false positives ranged from 1% to 21%, depending on the CAP definition.