Table 3.

 Subgroup analyses comparing effect of oral decontamination using antibiotic or antiseptic with no prophylaxis on incidence of ventilator associated pneumonia

Measurement	Antibiotic oral decontamination				Antiseptic oral decontamination
	Relative risk (95% CI)	No of studies (No of patients)	Ratio of relative risks (95% CI), P value*		Relative risk (95% CI)	No of studies (No of patients)	Ratio of relative risks (95% CI); P value*
Allocation:
Concealed†	0.73 (0.42 to 1.28)	3 (1031)	—		0.60 (0.40 to 0.89)	6 (2084)	—
Unconcealed	0.26 (0.03 to 2.19)	1 (67)			0.33 (0.14 to 0.80)	1 (60)
Blinding:
Blinded‡	—	—	NA§		0.66 (0.47 to 0.93)	5 (1986)	2.36 (1.09 to 5.10); 0.03
Unblinded	—	—			0.28 (0.14 to 0.56)	2 (158)
Patient population:
Medical or mixed	—	—	NA¶		0.70 (0.44 to 1.10)	4 (739)	1.67 (0.86 to 3.22); 0.13
Selected surgical or trauma	—	—			0.42 (0.26 to 0.67)	3 (1405)
Duration of ventilation (hours):
≥48	—	—	NA**		0.56 (0.34 to 0.91)	6 (1190)	—
<48	—	—			0.51 (0.34 to 0.75)	1 (954)
Ventilator associated pneumonia diagnostic criteria:							—
Quantitative culture of bronchoalveolar lavage fluid	0.58 (0.28 to 1.22)	2 (935)	0.74 (0.16 to 3.53); P=0.71		0.21 (0.07 to 0.64)	1 (98)	—
Non-quantitative culture of aspirate or others	0.78 (0.20 to 3.12)	2 (163)			0.61 (0.44 to 0.86)	6 (2046)

*Comparison of estimates in each subgroup (for example, concealed versus unconcealed trials).

†Concealed = reported as open, or unclear.

‡Patients, caregivers, and data collectors or outcome assessors blinded, or reported as double blind.

§None were unblinded.

¶None were surgical or trauma patients.

**None were ventilated for <48 hours.