Use and predictors of oral complementary and alternative medicine by patients with inflammatory bowel disease: a population-based, case-control study

Abstract

Background: The use of complementary and alternative medicine (CAM) in the general population and in patients with chronic diseases has increased markedly in recent decades. We aimed to determine the prevalence, type, and predictors of oral CAM use among patients with inflammatory bowel disease (IBD) compared with the general population in a large, population-based, case-control study.

Methods: Overall, 1370 patients with IBD and 598 control subjects in Canterbury, New Zealand, were recruited. Environmental and phenotypic data were obtained through a questionnaire and case note review. Predictors of oral CAM use were identified using binary logistic regression.

Results: In the previous year, 44.1% of patients with IBD and 42.3% of control subjects used oral CAM (odds ratio [OR], 1.078; 95% confidence interval [CI], 0.885-1.312). The types of oral CAM used most frequently were vitamins (Crohn's disease [CD], 25.2%; ulcerative colitis, 23.7%; control subjects, 24.9%), followed by herbs (CD 15.1%, ulcerative colitis 15.2%, control subjects 12.8%), and dietary supplements (CD, 8.5%; ulcerative colitis 12.6%, control subjects 12.1%). Female gender (OR, 1.61; 95% CI, 1.25-2.08), younger age (P = 0.005), higher education (P = 0.002), higher income (P = 0.04), being a vegetarian (OR, 3.58; 95% CI, 1.97-6.48) and a middle social class at birth (P = 0.024) were independent predictors of oral CAM use in patients with IBD. Disease phenotype was not associated with oral CAM use. In control subjects, female gender (OR, 2.67; 95% CI, 1.85-3.86), higher education (P = 0.003) and a diagnosis of asthma (P = 0.017) predicted oral CAM use.

Conclusions: Oral CAM use is common in, and does not differ between, patients with IBD and the general population in Canterbury, New Zealand. Socio-demographic factors, and not disease phenotype, predict oral CAM use in patients with IBD.