STATEMENT 5

1. APAGE Working Party on Diagnosis, Genetic, Epidemiology Management and Surgical Perspective of Crohn's Disease in Asia Pacific

2. STATEMENT 5 • There is considerable variation in the distribution of disease location for Crohn's disease although within East Asia, combined small and large bowel predominates

3. Comments: • Quality of the diagnostic procedures should be discussed. Poor diagnostic procedures may affect to the variation in the distribution. • Ileocecal involvement predominates • Limited database

4. Problems in identifying disease location in CD • Different classifications used (none/Vienna/ Montreal) • Objective upper GI and small bowel assessment not carried in all patients

5. Satsangi et al, GUT 2006

8. Quality of evidence I Evidence obtained from at least 1 RCT II-1 Evidence obtained from well-designed control trials without randomization II-2 Evidence obtained from well-designed cohort or case-control study II-3 Evidence obtained from comparison between time or place with or without intervention III Opinion of respected authorities, based on clinical experience and expert committees

9. Classification of Recommendation A There is good evidence to support the support the statement B There is fair evidence to support the support the statement C There is poor evidence to support the statement but recommendation made on other grounds D There is fair evidence to refute the statement E There is good evidence to refute the statement

10. Suggested modification • Although there is considerable variation in the distribution of disease location for Crohn's disease within Asia, the commonest disease location is ileocolonic.

11. Statement 6 • Similar to Western population, Crohn 's patients in the Asia-Pacific have a tendency towards progression of intestinal complications such as strictures and fistulas with time.

12. Comments: • More epidemiological studies needed from other regions • Strength of natural history? • Aren't surgery rates lower in Asian populations? 18.2% in a SL population of CD patients.

13. Disease behaviour

14. Percentage of CD patients with previous surgery 48% 47.1% 42% 31.2% 25.5% 27% 18.2%

15. 31.3% 50.7% Ye et al, Scand J Gastroenterol. 2010

16. Chow et al, Inflamm Bowel Dis 2008

17. Quality of evidence I Evidence obtained from at least 1 RCT II-1 Evidence obtained from well-designed control trials without randomization II-2 Evidence obtained from well-designed cohort or case-control study II-3 Evidence obtained from comparison between time or place with or without intervention III Opinion of respected authorities, based on clinical experience and expert committees

18. Classification of Recommendation A There is good evidence to support the support the statement B There is fair evidence to support the support the statement C There is poor evidence to support the statement but recommendation made on other grounds D There is fair evidence to refute the statement E There is good evidence to refute the statement

19. Statement 7 • A positive family history of IBD is uncommon among Crohn's disease patients and is likely to be related to a low prevalence of IBD in the region

20. Not for ANZ - 2.5X increased risk of first degree relative and 7X increased risk of two relatives with IBD in Canterbury, NZ • not sure whether "is likely related to a low~" is correct.

22. Familial Occurrence of Inflammatory Bowel Disease in Korea, Park et al, Inflamm Bowel Dis 2006

23. Familial Occurrence of Inflammatory Bowel Disease in Korea, Park et al, Inflamm Bowel Dis 2006

24. Quality of evidence I Evidence obtained from at least 1 RCT II-1 Evidence obtained from well-designed control trials without randomization II-2 Evidence obtained from well-designed cohort or case-control study II-3 Evidence obtained from comparison between time or place with or without intervention III Opinion of respected authorities, based on clinical experience and expert committees

25. Classification of Recommendation A There is good evidence to support the support the statement B There is fair evidence to support the support the statement C There is poor evidence to support the statement but recommendation made on other grounds D There is fair evidence to refute the statement the statement E There is good evidence to refute the statement

26. Modified Statement 7 • A positive family history of IBD is uncommon among Crohn's disease patients in areas of low prevalence.

27. Proposed additional statements

28. Statement 8 • The cause for the increasing incidence and prevalence of CD in the Asia Pacific Region remains unknown. Environmental changes are likely to play a role.

29. Minimal data available • A Japanese review suggested that prevalence of CD and UC began to increase > 20 years after an increased daily consumption of dietary animal meat and fats, milk and dairy products, and after a decreased consumption of rice.

31. Asakura JOGH 2008

32. CD and the environment • The New Zealand population study found • Positive association with • High social class at birth • City living • Negative association with • History of being breastfed • Having a childhood vegetable garden

33. Quality of evidence I Evidence obtained from at least 1 RCT II-1 Evidence obtained from well-designed control trials without randomization II-2 Evidence obtained from well-designed cohort or case-control study II-3 Evidence obtained from comparison between time or place with or without intervention III Opinion of respected authorities, based on clinical experience and expert committees

34. Classification of Recommendation A There is good evidence to support the support the statement B There is fair evidence to support the support the statement C There is poor evidence to support the statement but recommendation made on other grounds D There is fair evidence to refute the statement E There is good evidence to refute the statement

35. Statement 9 • Smoking has been shown to be positively associated with CD in New Zealand but in other parts of the Asia Pacific region, the role of smoking has not been determined

36. Very little data on smoking and CD available in the Asia Pacific region • Population study in Canterbury, New Zealand (Gearry et al) found cigarette smoking at diagnosis was positively associated with CD OR 1.99; 95% CI:1.48–2.68 • Leong et al found that among Chinese patients, ex-smokers, but not current smokers or previous and current smokers combined were at greater risk of developing CD • Another study by Leong et al found that current or previous smoking protected against the development of granulomas (OR: 0.16; 95% CI: 0.04-0.59)

37. Quality of evidence I Evidence obtained from at least 1 RCT II-1 Evidence obtained from well-designed control trials without randomization II-2 Evidence obtained from well-designed cohort or case-control study II-3 Evidence obtained from comparison between time or place with or without intervention III Opinion of respected authorities, based on clinical experience and expert committees

38. Classification of Recommendation A There is good evidence to support the support the statement B There is fair evidence to support the support the statement C There is poor evidence to support the statement but recommendation made on other grounds D There is fair evidence to refute the statement E There is good evidence to refute the statement