A soil transfer field experiment was designed in order to study (i) whether and how Collembolan communities are affected by sudden perturbation (a shift from agricultural land to heathland, and the reverse), and (ii) whether different species respond similarly and to the same extent as a function of their habitat preference (ascertained by controls).
Of the 254 incident KD cases ascertained, no controls could be found for one case.
Of the 808 incident HD cases ascertained, no controls could be found for 12 of the cases.
Mammograms were only ascertained on controls for this analysis, as the focus of the study was to understand the genetics of mammographic density among healthy women.
However, major indicators of health behaviour or confounders that are associated with risk of CRC were ascertained and controlled for in the multivariate analysis, such as former health check-up visits or former endoscopy of the large intestine.
Most reports (24, 75%) presented multivariate data analyses, usually multivariate logistic regression, where the independent contribution of various variables to the variance in psychotropic drug use could be ascertained while controlling for the contribution of other variables.
LMMs enable the effects of each of a number of independent variables on the dependent variable to be ascertained while controlling for the effects of the other variables in the model.
Subjects in Phase I were 882 cases and 473 controls ascertained through the EPICOLON II Project and 194 additional controls from the Spanish National DNA bank.
A preliminary study of 393 individuals (293 cases and 100 controls) ascertained at Vanderbilt revealed an increased occurrence of 4917G in cases compared to controls (15.4% vs.9.0%, p = 0.11).
24, 25 A total of 797 patients with melanoma, 441 population controls ascertained by the family doctor of each case and 103 unaffected siblings of cases (sibling controls) participated as described previously.
The STA study (285 controls4 controls) ascertained participants from six counties in northern California including invasive ovarian cancer cases and age-matched controls obtained using random-digit dialling.
