Acute Pulmonary Embolism: Impact of Selection Bias in Prospective Diagnostic Studies

Abstract

We evaluated selection bias in a prospective study of 1162 consecutive patients with suspected pulmonary embolism. Of these, 983 were eligible, and 627 could actually be included. During two months extensive data were collected on all non-included patients. Finally, our patient characteristics were compared with those of the PIOPED study (1990) and the study of Hull et al. (1994). Compared with included patients, the non-included patients had more often non-diagnostic V/Q scans (50% vs. 36%, p * Participating investigators are listed in the Appendix (see p. 608).