To minimize confounding by changing street environments, case families were asked if environmental modifications were made since the time injury.
To minimize confounding by diagnosis, we excluded all cases with a breast cancer diagnosis before primary hyperparathyroidism (n = 59).
Therefore, in order to minimize confounding by distribution of cell types, we performed case-control and survival analyses using 336 EOC cases and 398 controls, accounting for cell type associations to better understand the role of blood-based DNAm in ovarian cancer risk and survival.
These effects persisted after adjusting for coincident environmental factors and using both smoothers and a case-crossover approach to minimize confounding.
Inclusion of only single level cases, without degenerative changes to the other levels, will therefore minimize confounding.
To minimize confounding of biomarker associations with ARDS by clinical variables, such as severity of illness, cases and controls were one-to-one matched for severity of illness (APACHE II, within one point), age (within 10 years), gender (one-to-one match) and number of non-pulmonary organ failures (within one).
Cases and controls were categorized into 12 broad geographical regions within Great Britain to minimize confounding due to variation in allele frequencies across the country.
Strengths of the present study included the design with cases identified in a large population based clinical register and the use of matched controls in order to minimize confounding of the socioeconomic variables, and also the baseline determination of outcome variables at the age of one year before breast cancer diagnosis for the cases.
In each case bias must be avoided either when choosing the particular samples and their number that make up the data set, or in analysing the data and methods to minimize confounding variables.
To minimize confounding factors due to ethnical differences, all patients selected in the study were Caucasians and had European origins.
