Table 2.
Incidence rates and relative risks of hypertension in initiators of TNF-alpha inhibitors compared to the initiators of non-biologic disease-modifying anti-rheumatic drugs (DMARDs) for rheumatoid arthritis
| nbDMARDs | TNF-α inhibitors | |
|---|---|---|
| Hypertension Events | 97 | 273 |
| Follow-up (person-years) | 2,338 | 7,580 |
| Crude incidence rates/1000 person-years (95% CI) | 42 (34–51) | 36 (32–41) |
| Unadjusted HR | 1 | 0.85 (0.67–1.1) |
| Adjusted HR for only time-fixed covariatesa | 1 | 0.92 (0.73–1.2) |
| Adjusted HR for time-fixed and time-varying covariatesb using IPTWc | 1 | 0.95 (0.74–1.2) |
Abbreviations: CI- Confidence interval, HR- Hazard ratio, IPTW- Inverse probability treatment weights, TNF- tumor necrosis factor.
Time-fixed covariates (measured at initiation of either TNF-inhibitor of non-biologic DMARDs): gender, diabetes, hyperlipidemia, lipid-lowering agent use, anti-diabetic medication use, obesity, smoking, combined comorbidity score.
Time-varying covariates (updated monthly post-initiation of either TNF-inhibitor of non-biologic DMARDs): use of non-steroidal anti-inflammatory drugs, injectable steroids, cumulative dose of oral steroids, methotrexate use, leflunomide or cyclosporine use, other non-TNF biologic use, hospitalizations, emergency room visits, office visits, and number of distinct drugs, and age (updated every year in the study).
Weights were truncated at the 1st percentile (0.63) and 99th percentile (1.71). Mean (SD) of the weights were 0.99 (0.16) after truncation.