In some cases heterogeneity was present for significant predictors of entry (age, cognitive impairment, lives alone, married, number of children, Caucasian race) and time to NH admission (age, Caucasian race).
The remaining 7 predictor variables were considered for entry into the stepwise regression procedure: population density, proportion under age 15 years, proportion over age 60 years, life expectancy, gross domestic product, expenditure on health, and purchasing power parities.
Using data from 130 countries, with the consideration of the correlation between variables, and preventing multi-collinearity, seven out of the 12 predictor variables were selected for entry into the stepwise regression procedure.
Logistic regression models were used to ascertain predictors for QOL, with forced entry of fixed risk factors (block one) and modifiable risk factors (block 2).
When all factors (of Table 3) were entered into a stepwise Cox regression (P<0.01 for entry), the two predictors selected were pN status and margins.
Table 1 shows the descriptive statistics for the baseline variables that were considered for entry into pretreatment predictor models.
Of the ten predictor variables that met the criteria for entry into the multivariate logistic regression model, only marital status (P < 0.001), type of relationship (P < 0.05) and CAB (P < 0.001) were the significant predictors (r = 0.37) of condom use among the participants, after adjusting for all variables in the model (Table 4).
Although not a pre-requisite for entry into this study, this and other predictors of response will be the subject of associated translational research.
P-values of predictors were set to a level of 0.1 in the univariate analysis for entry in the regression analysis.
While several co-variates met the pre-specified p value cut-off for entry into the multivariable model, after backwards elimination of non-significant predictors, only adherence remained.
