Data were analyzed with SPSS (Statistical Package for the Social Sciences) 11.0 statistical package program. In comparison of continuous data of “dependent groups”, t-test was used for parametric conditions, whereas “Wilcoxon test” was used for non-parametric conditions. “Mann-Whitney U test”, which was a non-parametric test, was used in comparison of continuous data of independent groups. “Mc Nemar test” was used in comparison of discrete data of dependent groups, whereas Chi-square test was used for the comparison of independent groups. A p value lower than 0.05 was considered significant [21].
Considering the settle plate method as threshold standard (as maximum acceptable IMA value, the values i.e. 75 cfu for bacteria and 19 cfu for fungi were taken), ROC (Receiver Operating Characteristics) curve related to the air sampler was used. ROC curve is the method used to determine the appropriate cut-off points for optimal sensitivity and specificity as well as to evaluate the diagnosis capability of a medical test [21]