Study designs of evaluations included in the review
No inclusion criteria relating to the study design were specified. Prospective studies and a retrospective chart review were included.
Specific interventions included in the review
Studies evaluating the sputum Gram's stain in CAPP were eligible for inclusion. No detailed inclusion criteria relating to the index test were specified. A positive Gram's stain was defined as an average of greater than 10 organisms of proper pneumococcal structure per oil immersion field, greater than 50% of organisms on the slide of proper structure, or when either of these two criteria were met.
Reference standard test against which the new test was compared
The included studies were required to use an independent reference standard to confirm the diagnosis. No detailed inclusion criteria relating to the reference standard were specified. The reference standards included sputum culture, culture of transtracheal aspirate, culture of bronchial aspirate, or a combination reference standard in which the result was deemed positive if one or more of several tests were positive. Blood culture was used as a reference standard in one study in which all the patients had bacteremia.
Participants included in the review
Studies of patients with community-acquired pneumonia were eligible for inclusion.
Outcomes assessed in the review
The included studies were required to report sufficient data for the generation of 2x2 contingency tables. The outcome measures reported by the review were sensitivity and specificity.
How were decisions on the relevance of primary studies made?
Three reviewers, who were blinded to the study authors and journal of publication, judged whether the articles met the inclusion criteria.