Table 3.

Intramammary infections (IMIs) in cows pre and post calving period: efficacy of treatment on cure rate for all pathogens causing mastitis.

Groups	Infected quarters		Cured quarter		Efficacy1 (%)	95% CI	P-value (χ2)
	Treated	Control	Treated	Control
Group A	46	38	34	13	53.7	35.0, 71.2	<0.0096
Group B	62	54	48	15	64.1	15.7, 79.0	<0.0157
Group C	79	44	66	10	73.6	17.2, 82.0	<0.0001
Group D	112	63	96	8	85.0	53.6, 92.1	<0.0001
Total	298	199	244	46	71.8	48.1, 67.9	<0.0001

For the total overall comparisons of the efficacy and P-value was compiled using the Mantel–Haenszel statistic χ² test because no significant heterogeneity of effects between groups existed.

¹Efficacy = 100 × (1 − cure risk ratio), where cure risk ratio = percentage of controlled quarters cured/percentage of treated quarters cured.