Patient-directed self-management of pain (PaDSMaP) compared to treatment as usual following total knee replacement; a randomised controlled trial

Table 6 Pain VAS outcomes at 72 h/discharge and 6 weeks

	Outcome	PaDSMaP Mean (sd)	TAU Mean (sd)	Estimated effect^a (95% CI)	Difference (95% CI) Adjusted ^b	Difference (95% CI) Fully adjusted^c
Intention to Treat analysis	VAS baseline	48.5 (23.8) n = 68	52.9 (22.3) n = 69
	VAS static 72 h/discharge	30.3 (21.7) n = 64	33.4 (24.0) n = 65	−3.1 (− 11.1, 4.9) p = 0.441	−3.2 (− 11.5, 5.0) p= 0.441	−3.2 (− 11.1, 4.7) p = 0.430
	VAS on mobilisation 72 h/discharge	34.6 (24.9) n = 60	41.2 (28.9) n = 64	− 6.7 (− 16.3,2.9) p = 0.170	−6.1 (− 16.2,3.9) p = 0.228	−5.7 (− 15.6,4.2) p = 0.258
	VAS 6 Weeks	24.4 (19.6) n = 65	25.9 (20.6) n = 67	− 1.5 (−8.4, 5.5) p = 0.676	− 0.87 (−7.9, 6.2) p = 0.808	− 0.5 (− 7.5, 6.6) p = 0.711
Per protocol analysis^d	VAS baseline	50.2 (21.8) n = 41	52.9 (22.3) n = 69
	VAS static 72 h/discharge	23.5 (18.4) n = 40	33.4 (24.0) n = 65	−9.9 (− 18.7, − 1.1) P = 0.028	−10.3 (− 19.3, − 1.3) P = 0.026	−9.6 (− 18.5, − 0.7) p = 0.035
	VAS on mobilisation 72 h/discharge	28.2 (21.8) n = 39	41.2 (28.9) n = 64	− 13.1 (− 23.8,-2.4) P = 0.017	−12.1 (− 23.2,-1.2) P = 0.030	− 11.5 (− 22.4,-0.6) P = 0.039
	VAS 6 Weeks	22.9 (20.5) n = 41	25.9 (20.6) n = 67	−3.0 (− 11.0, 5.1) p = 0.465	−1.7 (− 10.0, 6.7) P = 0.693	− 0.8 (− 9.1, 7.5) P = 0.849

^aEstimated treatment effect of self-medication compared to TAU calculated with the linear model (T-test)
^bT-test adjusted by baseline VAS, HADS anxiety, HADS depression as specified a priori
^cT-test adjusted by those from a set of variables selected, a priori, with p < 0.10 when predicting VAS static, after adjusting by variables in **
^dPer protocol treatment group is ‘Successful self-medication’ i.e. ‘Started self-medication and continuing at 72 h/discharge even if temporarily stopped during hospital stay’
Abbreviations: HADS Hospital anxiety and depression scale; PaDSMaP Patient-directed self-management of pain; TAU treatment as usual; VAS visual analogue scale

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