References

Ambler, G. and P. Royston (2001). Fractional polynomial model selection procedures: Investigation of type I error rate. Journal of Statistical Simulation and Computation 69, 89-108.

Royston, P. and D. G. Altman (1994). Regression using fractional polynomials of continuous covariates: parsimonious parametric modelling (with discussion). Applied Statistics 43, 429-467.

Royston, P. and W. Sauerbrei (2003). Stability of multivariable fractional polynomial models with selection of variables and transformations: a boostrap approach. Statistics in Medicine 22, 639-659.

Sauerbrei, W. and P. Royston (1999). Building multivariable prognostic and diagnostic models: Transformations of the predictors by using fractional polynomials. Journal of the Royals Statistical Society A 162, 71-94.

Sauerbrei, W. and P. Royston (2002). Corrigendum: Building multivariable prognostic and diagnostic models: Transformations of the predictors by using fractional polynomials. Journal of the Royals Statistical Society A 165, 399-400.

Sauerbrei, W., P. Royston, H. Bojar, C. Schmoor, and M. Schumacher (1999). Modelling the effect of standart prognostic factors in node-positive breast cancer. British Journal of Cancer 79, 1752-1760.

Royston, P. and Sauerbrei (2004). A new approach to modelling interactions between treatment and continuous covariates in clinical trials by using fractional polynomials. Statistics in Medicine 23, 2509-2525