Table 1.

Brief pain inventory severity and interference scores²

	Baseline	6 weeks	3 months	Difference baseline to 6 weeks	Difference baseline to 3 months	Difference 6 weeks to 3 months
Number	43	41	39	41	39	38
Mean severity score (95 % CI)	5.0 (4.4 to 5.6)	3.7 (3.1 to 4.4)	3.7 (3.0 to 4.4)	−1.2 (-1.66 to -0.75)	−1.12 (-1.65 to – 0.58)	0.07 (-0.37 to 0.5)
Mean interference score (95 % CI)	5.1 (4.4 to 5.9)	4.0 (3.2 to 4.8)	3.7 (3.0 to 4.5)	−1.10 (-1.62 to -0.59)	−1.17 (-1.69 to -0.65)	0.02 (-0.34 to 0.39)

²Mean (paired) difference is not calculated on the same set of patients as the raw mean because not all participants have measurements at both time points (and therefore we don’t observe a value for the change for these participants). Note that there are 39 participants with data at both baseline and 3 months, which is fewer than the number of participants at either one of the individual time points, hence difference between two figures e.g. 5.1-3.7=1.4 but in table reported as 1.17