bb‐Shaw 2015.

Study characteristics
Methods	Case‐control study using the University of Manitoba IBD Epidemiology Database (UMIBDED). The UMIBDED was linked to the Manitoba Immunization Monitoring System (MIMS), a population‐based database of immunisations administered in Manitoba.
Participants	All paediatric IBD cases in Manitoba, born after 1989 and diagnosed before 31 March 2008, were included. Controls were matched to cases on the basis of age, sex, and region of residence at time of diagnosis. Conditional logistic regression models were fitted to the data, with models adjusted for physician visits in the first 2 years of life and area‐level socioeconomic status at case date. A total of 951 individuals (117 cases and 834 controls) met eligibility criteria, with average age of diagnosis amongst cases at 11 years.
Interventions	Measles‐containing vaccinations (MMR) received in the first 2 years of life were documented, with vaccinations categorised as ‘None’ or ‘Complete’, with completeness defined according to Manitoba’s vaccination schedule. Vaccinations were defined based on the work of Hilderman and colleagues, with the following tariff codes used to define a measles‐containing vaccine: 8621, 8629, 8670, 8673.
Outcomes	The administrative data case definition used to identify patients with IBD was validated with the establishment of the population‐based UMIBDED in 1995; the UMIBDED contains extracted administrative data of IBD cases and their controls (at a 1:10 ratio) for those individuals with health coverage between 1 April 1984 and 31 March 2008. Residents of Manitoba who had resided in the province for at least 2 years were identified as having IBD if they had had at least 5 physician visits or hospitalisations with ICD‐9‐CM codes 555.xx (Crohn’s disease) or 556.xx (ulcerative colitis) recorded as a diagnosis at any time. Since 2004, ICD‐10‐CA codes were used for all inpatient contacts and for IBD included K50.xx and K51.xx.
Funding Source	Government
Notes	Conclusions: no significant association between completed measles‐containing vaccination in the first 2 years of life and paediatric IBD could be demonstrated in this population‐based study.
Risk of bias
Bias	Authors' judgement	Support for judgement
CCS ‐ case selection	Low risk	Adequate ‐ secure record ‐ representative series of cases
CCS ‐ control selection	Low risk	Adequate ‐ community
CCS ‐ comparability	Low risk	Adequate ‐ matched for age, sex, and region of residence at time of diagnosis
CCS ‐ exposures	Low risk	Adequate ‐ secure record
Summary Risk of Bias assessment	Low risk	Plausible bias is unlikely to have seriously altered the results.