Kuenzig ME, et al. - Researchers conducted a cohort study by using health administrative data from a universally funded healthcare plan in Alberta, Canada to evaluate the impact of asthma on the need for intestinal resection in patients with Crohn’s disease diagnosed between 2002 and 2008 while adjusting for smoking status, imputed from a smaller, secondary data set. They found that co-occurring asthma was not correlated with the risk of surgery in patients with Crohn’s disease. However, asthma was linked to an increased risk of Crohn’s disease. Findings revealed that this null association persisted after adjusting for smoking status. A novel method was described in this study to adjust for confounding (smoking status) in time-to-event analyses, even when the confounding variable was unmeasured in health administrative data.