^aThe following systematic reviews were the sources for these studies: George¹ (Table 1), Cook and Kollef² (Table 1), Chastre and Fagon³ (Table 1), Bergmans and Bonten⁴ (Table 22.5), Safdar et al.⁵ (Table 1) and Melsen et al.²¹ (Figure 3).

^bThe following systematic reviews were the source for these studies: Messori et al.¹¹ (Table 5–7), Subirana et al.¹² (Analysis 1.5 and 2.5), Siempos et al.¹³ (Figure 2) and Safdar et al.⁵ (Table 2).

^cLiberati et al.⁹ (Analysis 1.5 and 2.5) was the source for these studies.

^dBronchoscopic versus tracheal sampling for VAP diagnosis.

^eData are earliest to most recent year of publication.

^fData are median and interquartile range (IQR).

^gP = 0.0001, χ²= 26.3; degrees of freedom = 3, Kruskal–Wallis test.

^hP = 0.99, χ²= 0.13; degrees of freedom = 3, Kruskal–Wallis test.

ⁱP = 0.03, χ²= 8.7; degrees of freedom = 3, Kruskal–Wallis test.

^jComparison of VAP incidence of concurrent control groups of SDD versus benchmark groups, P = 0.005, two-sample t-test.

^kComparison of VAP incidence of intervention groups of non-antibiotic versus benchmark groups, P = 0.17, two-sample t-test.

^lComparison of VAP incidence of intervention groups of concurrent SDD studies versus benchmark groups, P = 0.004, two-sample t-test.

^mComparison of VAP incidence of concurrent control groups of concurrent SDD versus control groups of non-antibiotic studies, P = 0.03, two-sample t-test.