Geometric mean concentrations for each hormone in cases and controls were calculated and compared by testing the statistical significance of the trend of the log-transformed variable entered as a continuous term in conditional logistic regression models.
We assessed the dose- or duration-response effects according to the category of exposure and tested the trend by assessing the significance of the β coefficients (i.e., P value for trend) of exposure, which was regarded as a continuous variable.
We calculated risk ratios for disease changes over time by dividing the proportion of admissions and deaths in each category per decade by the corresponding value in the baseline period (1950 9) and we tested the trend in the sub-category with greatest changes by using the χ test for linear trend.
The relationship between diabetes-related metabolic measures and PA was assessed by testing trend association between the metabolic measures and levels of PA in categories (low, moderate, and high) using generalized estimating equations to account for correlations among related individuals within families.
Indeed, Shekhar, Mohan, Oliver, and Zhou (2012) attempt to do similar, by testing for the emergence of crime trends with multiple crime types.
The models allowed for linear, quadratic, and cubic trends in symptom scores over time, but only involved testing the treatment by linear trend interaction that is, based on the assumption that quadratic and cubic trends would be the same for both groups.
Figure 4 illustrates the trends in proportion of childless white women in the three pseudo-cohorts by age to graphically test the parallel trend assumption.
We analyzed the trend by testing for interaction of the social factor and survey year in a dataset pooled from all three surveys.
The T lymphocyte counts tended to decline over the 2 year period, as tested by the trend over time repeated measures ANCOVA analysis.
We then tested the linear trend by a likelihood ratio test, comparing the model with the newly generated quantitative and discrete variable with the categorical variable.
