Only those patients who underwent DNA testing for BRCA1/2 mutation before the diagnosis of contralateral breast cancer were included Left truncation was applied to correct for survival bias that may occur in studies with patient recruitment at a variable time after diagnosis (see statistical analysis).
There can be many reasons to use joint models of two survival endpoints, including giving a general description of the data, correcting for bias in survival analysis due to dependent dropout or censoring, and improving efficiency of survival analysis due to the use of auxiliary information [ 11].
To correct for potential survival bias, the analysis excluded carriers who were diagnosed more than five years before completion of the study questionnaire.
15 To correct for potential survival bias arising from the exclusion of exposed carriers who died from breast cancer long before questionnaire completion, we carried out our main analyses on relatively recent cases that is, carriers who received diagnosis of a breast cancer or who were censored within the five years before completion of the questionnaire.
In a Cox regression model, the patient's address was an independent risk factor for survival, after correcting for age and location of lesion (pure medulloblastoma vs. other), HR 2.2, p = 0.015.
Indeed, the female and male BCU curves become virtually identical at older ages after correcting for gender differences in survival (Fig. 4).
The Cox proportional hazard model was used to compute the association between regions of aberration detected by GISTIC and overall or progression free survival, correcting for multiple testing using the Benjamini-Hochberg method.
Colonies were counted and the surviving percentage was determined for clonogenic survival after correcting for plating efficiency.
Furthermore, using a multivariate Cox model analysis, we found that pRKIP expression remained a significant predictor of survival after correcting for the effects of stage and grade (P = 0.032, see Table 2).
