Parameters associated with response:
(1) type of Crohn's disease (inflammatory vs fistulous)
(2) smoking status (nonsmokers either never smoked, quit > 6 months prior, or smoke 1-4 cigarettes per day)
(3) use of immunosuppressive agents (6-mercaptopurine, azathioprine or methotrexate) prior to starting infliximab
For patients with inflammatory disease, a positive response was associated with:
(1) nonsmoking status (73% initial response in nonsmokers vs 22% in smokers)
(2) immunosuppressive agent use (74% initial response in users vs 39% in nonusers)
Initial Response in patients with inflammatory Crohn's Disease
|
Factor
|
Odds Ratio
|
95% CI
|
p value
|
|
smoking
|
0.09
|
0.02 to 0.38
|
< 0.001
|
|
immunosuppressive agent use
|
4.23
|
1.37 to 3.07
|
0.01
|
from Table 2, page 711
Prolonged Response in patients with inflammatory Crohn's Disease
|
Factor
|
Odds Ratio
|
95% CI
|
p value
|
|
smoking
|
0.04
|
0.005 to 0.33
|
< 0.003
|
|
immunosuppressive agent use
|
9.15
|
2.54 to 32.97
|
0.01
|
from Table 2, page 711
Response for fistulous disease is defined as symptomatic reduction in drainage >= 50% for at least 4 weeks after completion of drug infusion.
Patients with fistulous disease who are nonsmokers have a longer duration of response to the infliximab, but there were no other significant predictors of response identified.
