Table 3 

Variables in multivariable analysis 

% (n = 47) articles 



Coding of variables in model 

Coding explicit for all candidate variables 
68 (32) 
Coding explicit for all variables in final model‡ 
70 (33) 


Coding of continuous candidate variables 

All continuous 
2 (1) 
All categorised/dichotomised 
51 (24) 
Combination of continuous and categorised variables 
19 (9) 
No continuous candidate variables 
0 (0) 
Unclear/not reported 
28 (13) 


Median (IQR) (range) 



Number of variables 

Candidates used to develop model* (n = 46) 
11 (7 to 14) (2 to 27) 
Included in final model** (n = 44) 
4 (3 to 6) (2 to 12) 


‡ Two papers could not be assessed as the final model was unclear. * In four articles variables were excluded where it was unclear if these were candidate variables. In one article the number of candidate variables was completely unclear ** Three articles could not be included: two because the final model was not presented in the paper, one because it was not clear which of the alternative models in the paper was the final model. 

Mallett et al. BMC Medicine 2010 8:20 doi:10.1186/17417015820 