Monitoring a Mandatory Nonmedical Switching Policy from Originator to Biosimilar Infliximab in Patients with Inflammatory Bowel Diseases: A Population-Based Cohort Study
Table 2
Patient characteristics for the policy cohort and the three historical cohorts.
Policy cohort
Historical cohorts
2019
2016
2017
2018
Age (years)
Mean (SD)
43.1 (16.9)
42.6 (16.1)
42.4 (16.5)
43.1 (16.5)
Median (range)
42.0 (5.0–90.0)
42.0 (5.0–89.0)
41.0 (5.0–88.0)
42.0 (4.0–89.0)
Sex, n (%)
Female
827 (45.0)
1104 (46.6)
1033 (46.1)
914 (45.8)
Male
1012 (55.0)
1264 (53.4)
1209 (53.9)
1080 (54.2)
Diagnosis of inflammatory bowel disease, n (%) †
Crohn’s disease
959 (52.1)
1186 (50.1)
1129 (50.4)
1040 (52.2)
Ulcerative colitis
466 (25.3)
603 (25.5)
561 (25.0)
488 (24.5)
Both
240 (13.1)
415 (17.5)
378 (16.9)
285 (14.3)
Undetermined
174 (9.5)
164 (6.9)
174 (7.8)
181 (9.1)
Patients with procedure in the previous year, n (%)
Endoscopy of the gastrointestinal tract ‡
541 (29.4)
891 (37.6)
757 (33.8)
527 (26.4)
Surgery of the gastrointestinal tract §
151 (8.2)
219 (9.2)
210 (9.4)
139 (7.0)
Years since first infliximab, mean (SD)
6.7 (3.4)
3.9 (3.2)
4.8 (3.2)
5.8 (3.3)
Number of different medications in the previous year
Any medication, mean (SD) ¶
6.5 (4.4)
7.2 (4.7)
6.8 (4.5)
6.7 (4.5)
Additional biologic medications, median (range) ††
0.0 (0.0–1.0)
0.0 (0.0–2.0)
0.0 (0.0–1.0)
0.0 (0.0–1.0)
Health services use in the previous year: Mean (SD)
Number of visits to a physician or nurse practitioner
17.9 (16.8)
31.1 (26.0)
23.0 (19.4)
19.7 (17.8)
Number of nights in hospital
0.6 (5.4)
1.3 (6.9)
0.8 (4.0)
0.6 (3.9)
SD: standard deviation. †Algorithm for identifying inflammatory bowel disease is presented in Supplementary Table 2. ‡Procedure codes for endoscopy of the gastrointestinal tract are listed in Supplementary Table 4. §Procedure codes for surgery of the gastrointestinal tract are listed in Supplementary Table 5. ¶Including infliximab. ††Excluding infliximab (biologic medications are listed in Supplementary Table 3). The policy cohort comprised individuals with a prescription for originator infliximab during a 6-month identification period between March 7, 2019 and September 4, 2019, the day before policy introduction. The three historical cohorts consisted of individuals with a prescription for the originator infliximab during 6-month identification periods between March 7 and September 4, 2016, 2017, and 2018.
