Research Article

Adherence to Methotrexate in Rheumatoid Arthritis: A Danish Nationwide Cohort Study

Table 3

Risk of nonadherence to MTX: Cox proportional hazard model; crude and multiply adjusted hazard rates (HR) and 95% confidence intervals (CI).

Variables at baseline5 mg per week7.5 mg per week5 mg per week#7.5 mg per week#
Crude OR (95% CI)Crude OR (95% CI)HR (95% CI)HR (95% CI)

Gender (F/M)1.21 (1.13–1.30)1.18 (1.11–1.26)1.12 (1.06–1.19)1.07 (1.01–1.12)
NSAID within last year1.09 (1.01–1.16)1.08 (1.01–1.15)1.03 (0.97–1.09)1.01 (0.96–1.06)
Prednisolone within last year0.91 (0.86–0.97)0.93 (0.88–0.98)0.99 (0.94–1.04)1.00 (0.96–1.04)
Biological antirheumatic therapy0.74 (0.24–2.32)1.48 (0.54–4.07)0.65 (0.24–1.73)1.04 (0.52–2.09)
AMI0.90 (0.77–1.05)0.85 (0.73–0.98)1.07 (0.93–1.22)1.01 (0.90–1.14)
Cerebrovascular events0.94 (0.82–1.08)0.95 (0.84–1.09)1.11 (0.99–1.25)1.14 (1.03–1.26)
Dementia0.77 (0.47–1.26)1.01 (0.65–1.57)1.14 (0.75–1.74)1.46 (1.05–2.02)
T1D with complications1.07 (0.79–1.45)1.01 (0.75–1.35)0.97 (0.71–1.33)0.92 (0.69–1.21)
T2D with complications1.29 (1.01–1.65)1.26 (0.99–1.59)1.34 (1.07–1.68)1.30 (1.06–1.58)
T1D1.06 (0.84–1.33)1.05 (0.84–1.31)0.93 (0.72–1.19)0.96 (0.78–1.19)
T2D1.05 (0.90–1.23)1.08 (0.93–1.25)1.06 (0.91–1.24)1.10 (0.96–1.25)
Hemiplegia1.36 (0.66–2.81)1.14 (0.56–2.33)1.45 (0.82–2.57)1.33 (0.78–2.24)
Heart failure0.91 (0.77–1.08)0.94 (0.81–1.10)1.12 (0.97–1.29)1.20 (1.06–1.36)
Atherosclerosis0.93 (0.79–1.09)1.01 (0.86–1.17)1.12 (0.97–1.28)1.23 (1.10–1.39)
COPD1.10 (0.98–1.22)1.03 (0.93–1.14)1.23 (1.12–1.35)1.21 (1.11–1.31)
Leukemia0.65 (0.28–1.51)1.06 (0.51–2.20)0.85 (0.41–1.79)1.37 (0.80–2.37)
Lymphoma0.93 (0.61–1.42)0.96 (0.64–1.43)1.03 (0.72–1.47)1.05 (0.77–1.42)
Metastatic malignancy0.62 (0.39–0.99)0.60 (0.39–0.92)0.85 (0.57–1.29)0.90 (0.63–1.28)
Mild liver disease1.35 (1.02–1.78)1.25 (0.95–1.65)1.30 (1.05–1.63)1.28 (1.05–1.56)
Moderate liver disease0.65 (0.28–1.51)0.68 (0.32–1.46)0.70 (0.33–1.47)0.76 (0.41–1.42)
Kidney disease1.39 (1.11–1.73)1.30 (1.04–1.61)1.35 (1.14–1.61)1.31 (1.12–1.53)
Solid cancer0.91 (0.75–1.11)0.85 (0.71–1.03)1.05 (0.89–1.24)1.00 (0.86–1.16)
Ulcer disease0.94 (0.83–1.06)0.96 (0.85–1.07)1.07 (0.96–1.18)1.08 (0.98–1.18)
Age
 <50 years 1 (reference)1 (reference)1 (reference)1 (reference)
 50–59 years0.79 (0.72–0.86)0.76 (0.70–0.82)0.84 (0.79–0.90)0.83 (0.78–0.88)
 60–69 years0.59 (0.55–0.65)0.58 (0.53–0.63)0.70 (0.66–0.76)0.73 (0.69–0.78)
 ≥70 years0.59 (0.54–0.64)0.61 (0.56–0.66)0.77 (0.72–0.83)0.89 (0.83–0.95)
Private practising rheumatologist0.95 (0.89–1.03)0.99 (0.92–1.06)0.97 (0.92–1.03)1.02 (0.97–1.07)
Difference from diagnosis to MTX
 <0.5 years1 (reference)1 (reference)1 (reference)1 (reference)
 0.5–0.99 years0.69 (0.64–0.75)0.74 (0.69–0.80)0.74 (0.69–0.79)0.80 (0.76–0.85)
 ≥1 year1.07 (1.00–1.15)1.02 (0.96–1.09)1.17 (1.11–1.24)1.21 (1.15–1.27)

F: female; M: male; AIDS: acquired immune-deficiency syndrome; AMI: acute myocardial infarction; T1D: type 1 diabetes; COPD: chronic obstructive pulmonary disease.
#Mutually adjusted for the other variables in the table (Cox proportional hazard regression).
< 0.05.