Correction [1]: It was recently brought to our attention that, although the statistical analyses in Table four had passed the original peer-review of this paper, the risk ratio and value of the lower 95% confidence interval for some of the variables in Table four were not consistent with the p values. We have repeated the multi-variant statistical analysis of the original data with StatView software. This analysis produced different values for the risk ratios and 95% confidence intervals for variables other than age. The corrected Table four is presented below (table 1). The p values are unchanged, thus the original conclusions of the article are not altered.

Table 1 Corrected table four