. 2019 Nov 13;81(1):22–29. doi: 10.1007/s00056-019-00200-x

Table 3.

Coefficients, associated confidence intervals (95% CIs), and P-values from the random effects linear models for R_a, R_z, R_max by system, thickness, grain size group, and time

	R_a				R_z				R_max
System^a	Coefficient	P-Value	95% CI	System^b	Coefficient	P-Value	95% CI	System^c	Coefficient	P-Value	95% CI
DS	0.181	0.505	−0.350, 0.712	DS	11.852	0.144	−2.851, 26.554	DS	12.263	0.141	−4.060, 28.587
IS	0.175	0.516	−0.353, 0.703	IS	5.022	0.500	−9.587, 19.632	IS	5.045	0.542	−11.175, 21.264
SDC	−0.491	0.109	−1.091, 0.109	SDC	−3.543	0.676	−20.153, 13.608	SDC	−0.428	0.964	−18.871, 18.014
OT	0.695	0.009*	0.172, 1.219	OT	11.195	0.130	−3.290, 25.680	OT	11.776	0.151	−4.305, 27.857
OS	Reference			OS	Reference			OS	Reference
Grain size	−0.008	0.323	−0.025, 0.008	Grain size	−0.244	0.304	−0.709, 0.221	Grain size	−0.179	0.496	−0.695, 0.337
Thickness	0.194	0.003*	0.068, 0.321	Thickness	5.890	0.001*	2.282, 9.497	Thickness	5.319	0.010*	1.258, 9.379
Time	−0.171	0.000*	−0.203, −0.139	Time	−3.297	0.000*	−4.493, −2.100	Time	−2.788	0.001*	−4.422, −1.154

DS DiaStrip, IS Intensiv Ortho-Strips System, SDC G5-ProLign, OT Galaxy IPR Diamond Discs, OS OS Discs

^aOverall significance of system for R_a, P = 0.07

^bOverall significance of system for R_z, P = 0.33

^cOverall significance of system for R_max, P = 0.48

*Value statistically significant