Randomised controlled trial of rhinothermy for treatment of the common cold: a feasibility study

van de Hei, Susanne; McKinstry, Steven; Bardsley, George; Weatherall, Mark; Beasley, Richard; Fingleton, James

The recruitment and completion rates confidence intervals were estimated by the Clopper-Pearson exact method. Mixed linear models with an exponential-in-time covariance matrix were used to estimate the differences in modified Jackson scores by treatment and time. A post hoc interaction term tested if the response differed by whether the nasal swab results was positive or not. The confidence interval for the SD for the change from baseline modified Jackson score was estimated using a Chi-square distribution. Logistic regression was used to estimate Receiver Operating Characteristic curves for the probability of participants saying they were better compared to the change from baseline modified Jackson score. The times of measurement were chosen so that about half of participants reported they had improved by that time point. Individual sensitivities and specificities were calculated for change from baseline modified Jackson score of between -7 and -4 at these times.