Table 2.
Crude HRs and aHRs for IBD associated with use of DPP4i compared with therapeutic alternatives*
| Comparison | Database | Cohort | Number of patients | Duration (years) of treatment, median (IQR) | Person-years | Number of IBD events | IBD rate per 100,000 patient-years | Crude HR (95% CI) | PS-weighting HR (95% CI)† |
|---|---|---|---|---|---|---|---|---|---|
| DPP4i vs. SU | MarketScan | DPP4i | 117,548‡ | 1.21 (0.73–2.04) | 146,171 | 35 | 23.9 (17.2–33.3) | 1.08 (0.70–1.65) | 1.08 (0.70–1.68) |
| SU | 199,744‡ | 1.12 (0.66–1.96) | 238,558 | 53 | 22.2 (17.0–29.1) | ||||
| Medicare | DPP4i | 44,064§ | 1.42 (0.75–2.49) | NA | NTSR | 11.6 (5.8–23.1) | 0.52 (0.25–1.10) | 0.53 (0.24–1.15) | |
| SU | 110,806§ | 1.69 (0.90–2.91) | 202,385 | 44 | 21.7 (16.2–29.2) | ||||
| DPP4i vs. TZD | MarketScan | DPP4i | 146,880‖ | 1.27 (0.75–2.13) | 189,987 | 40 | 21.1 (15.4–28.7) | 0.67 (0.40–1.11) | 0.68 (0.37–1.26) |
| TZD | 60,237‖ | 1.09 (0.67–1.88) | 71,268 | 23 | 32.3 (21.4–48.6) | ||||
| Medicare | DPP4i | 58,690¶ | 1.50 (0.81–2.57) | 95,351 | 17 | 17.8 (11.1–28.7) | 0.58 (0.28–1.21) | 0.97 (0.40–2.37) | |
| TZD | 27,306¶ | 1.27 (0.74–2.18) | 39,834 | 12 | 30.1 (17.1–53.0) |
IQR, interquartile range; NTSR, numbers too small (<11) to report based on Center for Medicare and Medicaid Services rules and data use agreement (person-years is not shown in this case to block the number of events).
Analysis was based on as-treated exposure definition, follow-up started from 180 days (induction period) after the second prescription and ended at the earliest of the following events: 1) 180 days after the date of prescription change including discontinuation or initiating the other drug in the drug pair that is being compared; 2) the end of enrollment (the end of enrollment for Parts A, B, or D or enrollment for HMO for Medicare beneficiaries); 3) death (for Medicare beneficiaries only); 4) administrative study end (31 December 2016); or 5) observation of an incident IBD event.
PS-weighted HRs were standardized to the distribution of baseline covariates in DPP4i initiators.
Before the start of follow-up, the following patients were excluded from the PS-trimmed cohort (sample size shown in Table 1): 19,793 DPP4i initiators, including 21 with IBD events and 19,772 with discontinuation of enrollment or who reached end of study date; and 34,983 SU initiators, including 29 with IBD events and 34,957 with discontinuation of enrollment or who reached end of study date.
Before the start of follow-up, the following patients were excluded from the PS-trimmed cohort: 2,454 DPP4i initiators, including a few (NTSR) with IBD events and 2,449 who died, discontinued enrollment, or reached end of study date; and 7,014 SU initiators, including 14 with IBD events and 7,000 who died, discontinued enrollment, or reached end of study date.
Before the start of follow-up, the following patients were excluded from PS-trimmed cohort: 24,696 DPP4i initiators, including 20 with IBD events and 24,676 with discontinuation of enrollment or who reached end of study date; and 8,985 TZD initiators, including 6 with IBD events and 8,979 with discontinuation of enrollment or who reached end of study date.
Before the start of follow-up, the following patients were excluded from the PS-trimmed cohort: 2,593 DPP4i initiators, including a few (NTSR) with IBD events and 2,588 who died, discontinued enrollment, or reached end of study date; and 1,226 TZD initiators, including a few (NTSR) with IBD events and 1,223 who died, discontinued enrollment, or reached end of study date.