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. 2018 May 2;20:79. doi: 10.1186/s13075-018-1580-5

Table 4.

Logistic regression for predicting primary nonadherence in the MTX and B/T training samples

Methotrexate (MTX) (n = 584) Biologics/tofacitinib (B/T) (n = 323)
Odds Ratio 2.5% 97.5% Odds Ratio 2.5% 97.5%
Intercept 2.68 0.44 17.38 5.36** 1.70 17.81
Age at index prescription (vs 18–44 years)
 45–54 years 1.87 0.71 5.25 2.33# 0.97 5.90
 55–64 years 0.87 0.32 2.46 1.48 0.60 3.76
 65–69 years 2.30 0.56 9.87 2.32 0.64 8.65
 70–74 years 1.90 0.44 8.26 2.87 0.81 10.65
 75–79 years 2.24 0.50 10.18 1.78 0.46 6.94
 80+ years 4.92* 1.03 24.81 2.45 0.55 11.50
Male (vs female) 0.69 0.35 1.35 1.37 0.73 2.58
Race (vs white)
 African American 1.20 0.44 3.18 0.50 0.17 1.37
 Asian 0.21 0.02 1.44 1.66 0.07 20.14
 Other/unknown 0.27* 0.09 0.73 1.20 0.47 2.95
Geographic division (vs East North Central)a
 East South Central 1.83 0.17 21.00
 Middle Atlantic 1.21 0.40 3.59
 Mountain 2.46 0.39 14.75
 New England 3.76# 0.89 16.55
 Other/unknown 0.90 0.14 5.46
 Pacific 1.74 0.56 5.24
 South Atlantic/West South Central 1.69 0.78 3.79
 West North Central 2.44# 0.94 6.43
Commercial vs Medicare at indexa,b 1.17 0.45 3.09 0.19*** 0.08 0.43
Body mass index (vs healthy weight)a
 Underweight (< 18.5) 0.98 0.08 6.96
 Overweight (25.0–29.9) 1.03 0.44 2.42
 Obesity I (30.0–34.9) 1.08 0.43 2.67
 Obesity II (35.0–39.9) 1.11 0.34 3.41
 Obesity III (40.0+) 1.64 0.51 5.07
 Missing 3.28** 1.47 7.51
Active drug ingredient count during 12 months before index (vs 0)a
 1–5 0.13*** 0.04 0.37
 6–10 0.06*** 0.02 0.24
 11–15 0.08** 0.02 0.36
 16+ 0.06** 0.01 0.35
Time between RA diagnosis and first prescription (years)a 1.13 0.95 1.34
Diagnosis-based comorbidity indicators (EDCs) during 12 months before index
 ADM05: administrative concerns and nonspecific laboratory abnormalitiesa 2.21* 1.22 4.10
 GUI11: incontinencea 7.96** 1.92 35.40
Pharmacy-based comorbidity indicators (RxMGs) during 12 months before index
 MUSx020: musculoskeletal/inflammatory conditionsb 0.28** 0.12 0.63
 ALLx030: allergy/immunology/chronic inflammatorya,b 0.27*** 0.14 0.50 0.34*** 0.19 0.60
 CARx030: cardiovascular/high blood pressurea 0.40* 0.18 0.84
 GSIx020: general signs and symptoms/paina 0.63 0.32 1.22
 GSIx030: general signs and symptoms/pain and inflammationa 0.40** 0.21 0.74
 INFx020: infections/acute minora 0.88 0.43 1.79
 ENDx040: endocrine/diabetes without insulina 0.15# 0.01 0.86

RA rheumatoid arthritis, EDC Expanded Diagnosis Cluster, RxMG Rx-defined Morbidity Group

*p < 0.05

**p < 0.01

***p < 0.001

#p < 0.1

aImportant predictors selected by LASSO logistic regression for predicting MTX primary nonadherence

bImportant predictors selected for predicting B/T primary nonadherence; age, sex, and race were added to the predictive models regardless