Table 2.

Polyserial correlations and regression slopes of the m-BPI pain severity scale items with ADPS.

m-BPI pain severity scale	n	Correlation coefficient	Slope of items as a predictor for ADPS	p value
Pain right now	385	0.834	0.800	<0.001
Pain at its least in the last 24 hours	385	0.811	0.845	<0.001
Pain at its worst in the last 24 hours	385	0.874	0.820	<0.001
Pain on the average	384	0.842	0.890	<0.001

Patients with missing data on the BPI pain scales or ADPS at the endpoint were excluded from the correlation analysis. ADPS, average daily pain score; BPI, Brief Pain Inventory; m-BPI, modified Brief Pain Inventory.