The collected data were coded and analyzed using the Statistical Package for Social Sciences for Windows
version 16.0 (SPSS Inc., Chicago, IL, USA). Means and standard deviations were computed and reported. Also
t-test, Chi square, Pearson correlation coefficients and Logistic Regression were used to analytical analysis.
Finally to determine the diagnostic value of F/R ratio, the area under the receiver operating curve was used. In
this regard, P value < 0.05 was considered statistically significant.
This study was approved by ethical committee of Research Vice Chancellors of Mazandaran University of
Medical Sciences. All of the participants were informed of the purpose and design of the study as well as
confidentiality of gathered data. They have right to withdraw the study at any time and they provided written
informed consent before the beginning of study. Also, permission for data collection was obtained from the Area
University Chief Executive Officers.