Table 4.

Profile analysis results for Western Ontario and McMaster Universities Osteoarthritis Index.

Variable	Estimate	Standard Error	95% Confidence Intervals		t Value	P value
Intercept	43.88	2.27	39.44	48.33	19.31	<0.0001
Week 1	−4.85	1.44	−7.65	−2.05	−3.38	<0.001
Week 2	−7.70	1.44	−10.50	−4.90	−5.37	<0.0001
Week 3	−8.08	1.44	−10.88	−5.29	−5.63	<0.0001
active tDCS	−1.88	3.21	−8.17	4.40	−0.59	0.56
Week 1: active tDCS	0.12	2.03	−3.84	4.07	0.06	0.95
Week 2: active tDCS	−3.88	2.03	−7.84	0.07	−1.91	0.06
Week 3: active tDCS	−2.87	2.02	−6.82	1.09	−1.41	0.16

Note. The baseline is used as the reference level for the time factor, and the sham tDCS group is used as the reference level for the intervention factor. “Week 1: active tDCS” denotes the interaction between the time factor and the treatment.