Table 5. Results of two-piecewise linear regression model.

Cut-off point	Effect size (β)	95% CI	P value
DPM≤40	−0.005	−0.017, 0.007	0.423
40<DPM≤155	0.006	0.002, 0.013	0.047
DPM>155	−0.007	−0.012, −0.002	0.004

DPM, disintegration per minute