Skip to main content
Fig. 4 | BMC Medical Research Methodology

Fig. 4

From: Duration of the common cold and similar continuous outcomes should be analyzed on the relative scale: a case study of two zinc lozenge trials

Fig. 4

Survival curves for the treatment groups and for the 25% shortened placebo group cold durations for the Petrus [10] study. The solid curve indicates the zinc lozenge group, the dashed curve on the right hand side indicates the placebo group, and the dotted curve overlapping the zinc lozenge curve indicates the recovery curve obtained by shortening all the placebo group common cold durations by 25%. The difference between the placebo group and the zinc lozenge group is significant, P = 0.006 on the logrank test, whereas there is no difference between the zinc lozenge group and the 25% shortened placebo group common cold durations (P = 0.9). Cox regression model indicates that zinc lozenges increased the rate of recovery by RR = 1.77 (95% CI 1.16 to 2.7)

Back to article page