Table 2.

Unadjusted correlation coefficients comparing EQ-5D-5L and BPI responses

Correlation	Correlation coefficient	95% CI	P value
EQ-5D-5L vs BPI pain severity score
Intervention cohort baseline	0.73	0.65 to 0.79	<0.01
Intervention cohort 3 months	0.75	0.66 to 0.82	<0.01
Intervention cohort 12 months	0.73	0.63 to 0.80	<0.01
Usual care cohort 12 months	0.8	0.72 to 0.86	<0.01
EQ-5D-5l vs BPI pain interference score
Intervention cohort baseline	0.72	0.63 to 0.78	<0.01
Intervention cohort 3 months	0.71	0.62 to 0.79	<0.01
Intervention cohort 12 months	0.73	0.63 to 0.80	<0.01
Usual care cohort 12 months	0.83	0.76 to 0.88	<0.01

BPI, Brief Pain Inventory; EQ-5D-5L, EuroQol 5 Dimension 5 Level.