Statistical analysis
Data were coded and entered using the statistical package for the Social
Sciences (SPSS) version 26 (IBM Corp., Armonk, NY, USA). Data was
summarized using mean, standard deviation, median, minimum and maximum
in quantitative data and using frequency (count) and relative frequency
(percentage) for categorical data. Comparisons between quantitative
variables were done using the non-parametric Mann-Whitney test. For
comparison of serial measurements within each patient the non-parametric
Wilcoxon signed rank test was used (Chan,
2003a)(1) . For comparing categorical data, Chi
square (χ2) test was performed. Exact test was used instead when the
expected frequency is less than 5 (Chan,
2003b)(2) . Correlations between quantitative
variables were done using Spearman correlation coefficient
(Chan, 2003c)(3) . Logistic regression
was done to detect independent predictors of mortality
(Chan, 2004)(4) . P-values less than
0.05 were considered as statistically significant.