Study designs of evaluations included in the review
Studies with at least 25 patients appear to have been eligible for inclusion; other than that no inclusion criteria were specified.
Specific interventions included in the review
Studies evaluating clinical signs and symptoms and results of routine laboratory tests, chest radiographs, Gram stains and cultures of pulmonary secretion were eligible for inclusion. The included studies evaluated a variety of clinical variables (e.g. fever, abnormally high or low leucocyte counts), fluid specimens from blind bronchial aspirates or bronchoalveolar lavage (BAL), cell counts on pulmonary secretions (i.e. for neutrophils and organisms on Gram stain obtained by bronchoscopy), bacteria on Gram stain of pulmonary secretions, cultures of blind bronchial aspirate specimens with more than 1E5 colony forming units (CFU) per mL, BAL fluid of more than 1E4 CFU per mL, radiographic features, combinations of tests, and more than 6 scores on a clinical pulmonary infection scale.
Reference standard test against which the new test was compared
Studies comparing the evaluated indicators with histological examination of pulmonary tissue for VAP by biopsy or autopsy were eligible. The included studies used histology either alone or together with culture results, and all patients underwent full or limited immediate post-mortem lung biopsy.
Participants included in the review
Studies with immunocompetent patients who had undergone mechanical ventilation for at least 1 day were eligible for inclusion. Studies with more than 20% of patients with pneumonia on admission to the intensive care unit were excluded. Half of the included studies were in patients in French hospitals.
Outcomes assessed in the review
Studies had to describe the clinical findings for the included patients; other than that no inclusion criteria were specified. The included studies assessed test data 48 hours or less prior to histological evaluation, or the last clinical values measured before death were used (interval between measurement taken and autopsy unspecified). The review reported sensitivity, specificity, and positive (LR+) and negative (LR-) likelihood ratios.
How were decisions on the relevance of primary studies made?
The author did not state how the papers were selected for the review, or how many reviewers performed the selection.