Table 5.

MICs and MBCs of four disinfectants against CRPA isolates.

Disinfectant	CRPA group	MIC range	MIC50	MIC90	Unadjusted P (MIC)	Adjusted P or q (MIC)	MBC range	MBC50	MBC90	Unadjusted P (MBC)	Adjusted P or q (MBC)
Ethanol, % (v/v)	XDR (n=24)	75–75	75	75	0.100	q = 0.220	75–75	75	75	0.257	q = 0.336
Ethanol, % (v/v)	Non-XDR (n=56)	37.5–75	75	75			37.5–75	75	75
Chlorine-containing disinfectant, mg/L available chlorine	XDR (n=24)	128–1024	512	1024	0.956	q = 0.956	256–1024	1024	1024	0.294	q = 0.336
Chlorine-containing disinfectant, mg/L available chlorine	Non-XDR (n=56)	128–1024	512	1024			256–1024	1024	1024
Povidone-iodine, mg/L available iodine	XDR (n=24)	128–1024	512	1024	0.283	q = 0.336	256–1024	512	1024	0.110	q = 0.220
Povidone-iodine, mg/L available iodine	Non-XDR (n=56)	128–1024	512	1024			256–1024	512	1024
Benzalkonium bromide, mg/L	XDR (n=24)	32–256	64	128	<0.001	Holm P < 0.001	64–512	128	512	0.036	Holm P = 0.036
Benzalkonium bromide, mg/L	Non-XDR (n=56)	16–256	64	128			64–256	128	256

Groups were compared using the Mann–Whitney U test. Benzalkonium bromide MIC and MBC constituted the prespecified primary outcome family of two tests, to which the Holm procedure was applied; the remaining six comparisons constituted an exploratory family, to which the Benjamini–Hochberg procedure was applied. In a sensitivity analysis treating all eight endpoints as a single family, the benzalkonium bromide MIC difference remained significant (q = 0.001) whereas the MBC difference did not (q = 0.144). Ethanol endpoints are reported as volume fractions because the product is prepared and used volumetrically. The chlorine-containing disinfectant concentration label has been corrected from 2000 mg/L to 1024 mg/L available chlorine, the concentration actually tested. For benzalkonium bromide MIC, the Hodges–Lehmann median difference was 32.0 mg/L (95% CI 0.0–48.0), with a moderate-to-large effect size (r = 0.424). MIC, minimum inhibitory concentration; MBC, minimum bactericidal concentration.