Table 2.

Summary of outcome and mediator scores

Variable	Mean ± SD	95% CI	p-value
Numeric Pain Rating Scale (NPRS)	5.43 ± 1.32	5.15–5.71	0.027
WOMAC Physical Function Subscale (WOMAC-PF)	38.27 ± 9.81	35.84–40.70	0.031
EQ-5D-5 L Index	0.61 ± 0.15	0.58–0.64	0.045
Pain Catastrophizing Scale (PCS)	22.74 ± 7.54	20.89–24.59	0.018
SF-36 Physical Component Score	42.86 ± 8.29	40.68–45.04	0.023
SF-36 Mental Component Score	47.12 ± 9.45	44.58–49.66	0.036

NPRS = Numeric Pain Rating Scale; WOMAC-PF = Western Ontario and McMaster Universities Osteoarthritis Index– Physical Function Subscale; EQ-5D-5 L = EuroQol 5-Dimensions 5-Levels; PCS = Pain Catastrophizing Scale; SF-36 = Short Form Health Survey– 36 items; CI = Confidence Interval; SD = Standard Deviation

Note: All scores represent post-tDCS values only. No pre-treatment data were collected. Reported p-values reflect the results of normality testing using the Shapiro–Wilk test, not comparisons across time points