We used a multi-year panel design, multiple criterion and predictor variable measures, extensive statistical control for potential confounds including autoregressive prior histories of both reading and mathematics difficulties, and additional epidemiological methods to preliminarily examine these hypothesized relations.
Using a between-family design and several background factors (i.e., age, sex, sibship size, parental socio-economic status, and family structure), we were able to control for potential confounds, and estimate the links between birth order and outcomes across several different social categories.
Four covariates (smoking status, urine results, gender, and age) were included in this random-effects model in an effort to control for potential confounds.
To control for potential confounds, age, gender, PMI, brain pH, side of brain, duration of disease and psychotropic medication (lifetime antipsychotic dose expressed in fluphenazine milligram equivalents) were added as covariates, and assessed by ANCOVA for all three genes in all brain regions.
To control for potential confounds, age, gender, PMI, brain pH, side of brain, duration of disease, age of onset, severity of alcohol and drug abuse and psychotropic medication were added as covariates, and assessed by ANCOVA for all three subunits in the striatum and in the cerebellum.
To control for potential confounds, we will assess general self-efficacy with a 10-item, validated German scale (Skala zur Allgemeinen Selbstwirksamkeitserwartung, ASE) [ 62].
These variables were used as confounders to control for potential confounding.
Additionally, future studies should control for potential confounding factors.
However, several studies had methodological limitations, such as use of a limited sample size, lack of baseline assessment, and lack of control for potential confounding factors.
Results did not change after using logistic regression to control for potential confounding factors.
Finally, LISREL analysis was performed to control for potential confounding variables.
