Crude estimates for absolute and relative measures of VTE incidence in patients with inflammatory bowel disease who started treatment with a TNF-α inhibitor or nonbiologic agent
| Data source and treatment | No. of patients | PYs of follow-up | VTE events | IR/100 PY (95% CI) | IR difference/100 PY (95% CI) | IR ratio (95% CI) |
|---|---|---|---|---|---|---|
| Medicaid, 2000–2010 | ||||||
| Nonbiologics | 5041 | 3957 | 52 | 1.31 (0.98 to 1.72) | 1.00 (ref) | 1.00 (ref) |
| TNF-α inhibitors | 1439 | 1015 | < 11* | 0.79 (0.34 to 1.55) | −0.52 (−1.17 to 0.13) | 0.60 (0.29 to 1.26) |
| Medicare, 2007–2013 | ||||||
| Nonbiologics | 5166 | 5726 | 148 | 2.58 (2.19 to 3.04) | 1.00 (ref) | 1.00 (ref) |
| TNF-α inhibitors | 1480 | 1862 | 47 | 2.52 (1.86 to 3.36) | −0.06 (−0.89 to 0.77) | 0.98 (0.71 to 1.36) |
| Optum Clinformatics, 2004–2013 | ||||||
| Nonbiologics | 6291 | 5964 | 42 | 0.70 (0.51 to 0.95) | 1.00 (ref) | 1.00 (ref) |
| TNF-α inhibitors | 2254 | 2258 | 15 | 0.66 (0.37 to 1.10) | −0.04 (−0.44 to 0.36) | 0.94 (0.52 to 1.69) |
| Overall | ||||||
| Nonbiologics | 16 498 | 15 647 | 242 | 1.55 (1.36 to 1.75) | 1.00 (ref) | 1.00 (ref) |
| TNF-α inhibitors | 5173 | 5135 | 70 | 1.36 (1.06 to 1.72) | −0.19 (−0.56 to 0.18) | 0.88 (0.67 to 1.15) |
Note: CI = confidence interval, IR = incidence rate, PY = person-year, TNF = tumour necrosis factor, VTE = venous thromboembolism.
↵* Actual number suppressed, as required by data-use agreement with the Centers for Medicare and Medicaid Services for counts below 11.