Table 3. Mean bacterial counts in different areas of hospitals (CFU/m³).

	inpatient facilities				restricted areas
	without HVAC	conventional HVAC	enhanced HVAC	total	without HVAC	conventional HVAC	enhanced HVAC	total
n(studies)	61(2)	258(4)	42(1)	361(4)	10(1)	34(2)	3695(16)	3739(16)
mean	356.45	229.24	20	226.39	387.50	130.01	36.12	37.91
SD	177.18	106.02	NA	145.25	NA	153.55	39.74	46.64
95%CI	311.07–401.82	216.24–242.24	NA	211.36–241.43	NA	76.44–183.59	34.84–37.40	36.42–39.41
median	265	151.49	20	151.49	387.50	25.40	16.63	16.63
range	265–694	130–407	20	20–694	387.50	25–349	0–279	0–388

HVAC, heating, ventilation and air conditioning; n, number of samples; SD, standard deviation; CI, confidence interval; NA, not applicable.