Table 1.
Study Sample Attrition
| Parameter | Patients, N (%) |
|---|---|
| ≥1 claims for a targeted DMARDa 1/1/2010-9/30/2014 | 334,172 |
| ≥1 pharmacy or medical claims for a different targeted DMARDa during baseline period | 44,150 |
| 1 targeted DMARDa on index date | 43,928 |
| ≥12 months of continuous enrollment and pharmacy benefits before index date (baseline) | 33,220 |
| ≥12 months continuous enrollment and pharmacy benefits after index date (postindex) | 24,070 |
| Aged ≥18 years at index | 23,364 |
| ≥1 nondiagnostic medical claims with an ICD-9-CM diagnosis code (714.0x) for RAb | 13,050 |
| No claims for other autoimmune conditions for which biologics are usedc | 10,231 |
| Alive at end of 1 year postindex | 10,229 |
| Switching cohorts of interest (baseline to index) | |
| TNF inhibitor cyclers | 6203 (60.6) |
| TNF inhibitor-alternative MOA switchers | 2640 (25.8) |
| Alternative MOA cyclers | 699 (6.8) |
| Alternative MOA-TNF inhibitor switchers | 687 (6.7) |
a
Abatacept, adalimumab, certolizumab, etanercept, golimumab, infliximab, tocilizumab, or tofacitinib.
b
RA diagnosis in the primary or secondary position during baseline or 30 days postindex.
c
No inpatient or outpatient nondiagnostic claims in any diagnosis code position during baseline or any follow-up with an ICD-9-CM code for any other autoimmune condition for which biologics are used.
DMARD indicates disease-modifying antirheumatic drug; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; MOA, mechanism of action; RA, rheumatoid arthritis; TNF, tumor necrosis factor.