Table 2.

Association of MTX dosage with change in eGFR assessed using multiple linear regression analysis.

	βcoefficient	SD	p value	95% confidence interval forβ
MTX < 8 mg/week (vs. 8 ≤ MTX < 12 mg/week)	0.86	0.77	0.26	− 0.65 to 2.36
MTX ≥ 12 mg/week (vs. 8 ≤ MTX < 12 mg/week)	− 2.46	0.94	0.0089	− 4.30 to − 0.62

Age, sex, disease duration, body weight, baseline eGFR, hypertension, diabetes, concomitant use of NSAIDs, concomitant use of b/tsDMARDs, and DAS28-CRP were used in the multiple linear regression models to adjust for confounding factors related to MTX dosage and renal impairment.

b/tsDMARDs biological/targeted synthetic disease-modifying antirheumatic drug, CRP C-reactive protein, DAS28 28-joint Disease Activity Score, eGFR estimated glomerular filtration rate, NSAIDs nonsteroidal anti-inflammatory drugs.