Spss statistics for windows statistical package version 24

Statistical analyses were carried out using the IBM SPSS Statistics for Windows statistical package version 24 (SPSS Inc. Chicago, IL, USA). Descriptive details are reported as means, standard deviations, median and range or percentage, and relationships between variables were explored using Spearman's rank correlation analysis. Concentrations below the LOD were replaced by LOD/2. Our choice to limit the between-group statistical analyses to compounds with a prevalence > 60% is recommended by the US CDC. 17 Despite log 10 transformation, the OC distributions remained skewed positively to the right and were not normally distributed according to the Kolmogorov-Smirnov test and Q-Q residual plots. We therefore employed non-parametric statistics (the Mann-Whitney U test) for comparisons of OC concentrations between the two study sites. For related compounds, Levene's test demonstrated equal variances between the two study sites. In a univariate general linear model (UGML) adjusted for the continuous variables age and parity (excluding stillbirths), acceptable case-wise diagnostics were possible even though abruptions of normality were Finally, the ratios within the DDT group were calculated to distinguish ongoing chronic exposure versus dietary exposure or distant past exposure. 3, 18 3. Results