Manitoba Inflammatory Bowel Disease Cohort Study

Single Nucleotide Variations (SNPs) in gene encoding for membrane transporter proteins were investigated for associations with both IBDs. Target genes included SLC23A1, SLC22A4, SLC22A5, SLC22A23, SLC2A14, SLC2A2 but analyses are not limited to these.

The validated 7-item Mastery scale assesses the degree to which persons feel they have some control or mastery over their life to handle day-to-day challenges.

The IBD- Self Efficacy (SE) is a 29-item scale developed by Keefer et al. (1) based on patient interview, validated self-efficacy measures for other diseases. The instrument assesses the level of confidence in managing various disease-related "tasks," with item scores ranging from 1 (not at all) to 10 (totally), and higher scores reflecting greater disease self-management efficacy. Items were grouped conceptually into 4 subscales, reflecting domains identified by patients with IBD as important [1] managing stress and emotions (sample items: keep from feeling sad; do something to reduce stress); [2] managing medical care (sample items: take medication at instructed times; work out differences with doctors); [3] managing symptoms and disease (sample items: keep diarrhea/urgency from interfering; decrease fatigue); [4] maintaining remission (sample items: engage in self-care; maintain sense of well-being).

The Sheehan Disability Scale is a commonly used and validated instrument that measures disease interference in 3 primary domains of life: work, social, and home, based on a visual analog scale from 0 (no interference) to 10 (very severe interference). (1,2)

• Sheehan DV, Harnett-Sheehan K, Raj BA. The measurement of disability. Int Clin Psychopharmacol. 1996;11(suppl 3):89-95.
• Leon AC, Olfson M, Portera L, et al. Assessing psychiatric impairment in primary care with the Sheehan Disability Scale. Int J Psychiatry Med. 1997;27:93-105.

Perceived health was assessed using the General Health item from the Medical Outcome Survey Short Form 36, (1) which asks participants to characterize their health in the past year, using 5 response categories from "Excellent" to "Poor."

Current disease activity was assessed using standardized clinical indices, the Harvey-Bradshaw index for CD.

Current disease activity was assessed using standardized clinical indices, the modified Powell-Tuck index for UC.

Recent disease activity was measured with the Manitoba IBD Index

The Cohen Perceived Stress Scale is a 14-item questionnaire, with a 5-point Likert response format, that assesses the individual's appraisal of their stress "load" related to chronic and acute stressors.

The Brief Symptom Inventory is a well-established measure of current emotional distress related to multiple psychological symptoms, consisting of 53 items.

The Psychological Well-being Manifestations Scale consists of 25 items that query 6 general domains of positive experience using a 5-point Likert frequency scale, with higher scores indicating a greater sense of well-being.

The 32-item Inflammatory Bowel Disease Questionnaire is a validated measure that has been extensively used in IBD studies to assess disease-specific quality of life.