Spermatozoa counts increased with age for uninfected individuals (linear regression with quadratic term, factor ("Age") ^2, df = 1, F = 10.35, P = 0.001 and factor "Age" df = 1, F = 3.39, P = 0.07, Figure 6, left panel), but not for infected individuals (linear regression, factor "Age", df = 1, F = 0.05, P = 0.82, Figure 6, right panel).
For further multiple linear regression analysis, factor score was computed for each factor.
A collection of chemometrics methods such as multiple linear regression (MLR), factor analysis based multiple linear regression (FA-MLR), principal component regression (PCR), and partial least squared combined with genetic algorithm for variable selection (GA-PLS) were applied to make relations between structural characteristics and NK1R antagonism/SERT inhibitory of these compounds.
SEM is a generalization of linear regression and factor analysis models [ 30, 31].
By analysis using stepwise multiple linear regression, the factors associated with medical utilization were classified.
In the univariate linear regression, two factors explained a large amount of variation in the rate.
In the linear regression the factors with the greatest negative impact on the EQ-5D index were ischemic heart disease (type 1 diabetes), stroke (both diabetes types), neuropathy (both diabetes types), and fear of hypoglycaemia (type 2 diabetes).
In order to understand the effects of the variables of interest on factor scores, we applied a linear regression model with factor scores as independent variables and variables of interest as predictors.
In multivariate log linear binomial regression, factors associated with alcohol use consistently in each SCOPE centre were smoking during pregnancy (all countries) and ethnicity (Ireland, the UK and New Zealand).
According to the results of linear regression analysis, the factor scores were associated with several demographic factors, including age, sex, marital status and current smoking status.
For caesareans, five significant variables were detected by simple linear regression: (1) positive factor being "rachidian anaesthesia" (p=0.005); (2) and negative factors, "primary caesarean" (p=0.019), "primiparity" (p<0.001), "epidural anaesthesia" (p=0.001) and "Apgar under 7 at 1 min" (p=0.032).
