Table 3. Ordinal regression analyses with tumour pAkt-IR and nCB₁IR as the independent variables and the Gleason score, %ca or Ki67-index as the dependent variable.

	Main effects model		Interaction term included
	Estimate	Z-value	Estimate	Z-value
Gleason score
pAkt-IR	1.17±0.23	5.01	−0.40±0.83	−0.48
nCB1IR	0.49±0.21	2.36	−1.30±0.93	−1.41
pAkt-IR×nCB1IR			0.66±0.34	1.97
%ca
pAkt-IR	0.44±0.21	2.09	−2.37±0.86	−2.74
nCB1IR	0.86±0.21	4.02	−2.18±0.94	−2.33
pAkt-IR×nCB1IR			1.16±0.35	3.28
Ki67-index
pAkt-IR	0.94±0.23	4.05	−0.16±0.87	−0.19
nCB1IR	0.51±0.21	2.43	−0.69±0.94	−0.73
pAkt-IR×nCB1IR			0.45±0.35	1.31

The coefficients (± standard error) were determined from ordinal regressions (cumulative logit model) undertaken in the R statistical package (function vglm in the VGAM bundle). Gleason scores were divided as 4–5, 6, 7 and 8–10. The %ca and Ki67-index scores were divided into quartiles. In every case, the assumption of proportional odds was upheld. Significance levels for the Z-values are: ±1.96 for P = 0.05, ±2.58 for P = 0.01 and ±3.29 for P = 0.001. Note that in the analyses, the values returned for a variable in the main effects model represent its total effect when the other variable is included. In the interaction term model, the value for the individual variable is for a constant value of the other variable. The model returns three intercept coefficients for each level of the response, the reference level being the lowest level. These were as follows: Gleason score main effects model, −3.06, −4.51 and −5.52; model with interaction, 1.16, −0.30, −1.32; %ca main effects model, −1.66, −2.95, −4.01; model with interaction, 5.69, 4.36, 3.26; Ki67-index main effects model, −2.47, −3.70, −4.92; model with interaction, 0.41, −0.82, −2.04.