Crohn's disease: smoking may increase the risk of further surgery

Clinical bottom line (level 4)

  1. Around half of patients who had surgery for Crohn's disease had another operation within 11 years.
  2. Patients who smoked were more likely to require surgery.
Sutherland et al: Gastroenterology 1990; 98: 1123-1128
Expires May 2003

The study

Retrospective cohort study with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, Canada

235 patients (aged , 67% female) who had previously required surgery for Crohn's disease

Factors studied:
  • current smoking
  • smoking > 5 cigarettes per week for at least 12 months




    • 174 (74%) followed for mean 11 years
    Outcomes studied:
  • further surgery (excludes reoperation for 'technical' reasons)

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)    		 NNF
    (95% CI)
    further surgery 11 years 84/174 48%
    (41% to 56%)    		 2
    (2 to 2)

    prognostic factor for
    further surgery     		time to outcome unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    smoking mean 11 years 1.7
    (1.03 to 2.79)     		7
    (3 to 140)

    prognostic factor outcome present outcome absent unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    smoking 32 18 1.7
    (1.03 to 2.79)     		7
    (3 to 140)
    no smoking 57 67

    Comments

    1. Failure to adjust for confounding factors make these results far less certain.

    Citation

    1. Sutherland LR, Ramcharan S, Bryant H, et al: effect of cigarette smoking on recurrence of Crohn's disease. Gastroenterology 1990; 98: 1123-1128
    Search Terms: Crohn* in Cochrane
    Contributor: Chris Ball and Bob Phillips, October 1999
    Reviewer:

    Clinical Question.
    Patient Crohn's disease
    Intervention or Exposure smoking
    Outcome operation, surgery, resection