Although it is common practice to read tests with clinical information,
whether this improves or decreases the accuracy of test reading is uncertain.
To determine whether diagnostic tests are more accurate when read with
clinical information or without it.
MEDLINE search (1966-December 2003) extended by search of reference
lists and articles citing the articles retrieved (Web of Science, 1985-December
All articles comparing the accuracy of tests read twice by the same
readers, once without and once with clinical information, but otherwise under
identical conditions. Only articles that reported sensitivity and specificity
or receiver operating characteristic (ROC) curves were included.
Data were extracted by one author and reviewed independently by the
other. When the data were difficult to interpret, differences were resolved
Sixteen articles met the inclusion criteria. Eleven articles compared
areas under ROC curves for tests read with and without clinical information,
and 5 compared only sensitivity and specificity. Ten articles used actual
clinical information; 6 used constructed clinical information that was plausible.
Overall, clinical information improved test reading accuracy although the
effect was smaller in the articles using actual clinical information when
compared with those using constructed clinical information. There were no
instances in which clinical information resulted in significant reduction
in test reading accuracy. In some instances, improved test reading accuracy
came from improved sensitivity without loss of specificity.
At least for the tests examined, the common practice of reading diagnostic
tests with clinical information seems justified. Future studies should be
designed to investigate the best way of providing clinical information. These
studies should also give an estimate of the accuracy of clinical information
used, display ROC curves with identified data points, and include a wider
range of diagnostic tests.