MS-Excel was used to enter and manage the data. The significance of change in various parameters of the study were tested by using paired t-test where the data was normally distributed, otherwise its non-parametric equivalent test, Wilcoxon paired signed-rank test was applied. Data are expressed as mean ± SD unless otherwise indicated. Values of P <0.05 was considered significant. All statistical calculations were performed using statistical software SPSS (version 12, SPSS, Chicago, Il, USA) and Stata (version 9.2, Stata Corp, College Station, TX, USA).