CHP6 Results *UPGRADED VERSION*

1. CHP6 Results *UPGRADED VERSION* By Data Sub-group

2. Pilot Study Uneligible 1 Fully completed 28 Participated 30 Doors answered 96 Partially completed 2 Rejected 49 Total doors knocked 184 Uncontactable 16 Uncontactable 88

3. Fieldwork Uneligible 119 Fully completed 682 Participated 687 Doors answered 1559 Partially completed 5 Rejected 668 Total doors knocked 2046 Uncontactable 85 Uncontactable 487

4. Demographics of study sample Is our sample representative of the population?

5. Age & Gender

6. Ethnic group & Marital status

7. Educational level & Personal yearly income

8. Housing type

9. Prevalence of the usage of dietary supplements in Singaporean adults (“use” and “dietary supplements” as defined by Lit Review)

10. Prevalence

11. No. of different supplements used • n: 382 • Median: 2 • Inter-quartile range: 1 – 4

12. Average length of use • n: 380 • Median:3 yrs • Inter-quartile range:1 yr 3 mnths – 6 yrs 3 mnths

13. Longest length of use • n: 380 • Median:4 yrs 6 mnths • Inter-quartile range: 2 yrs – 10 yrs

14. Spending on supplements per year • n: 348 • Median:$200 • Inter-quartile range:$100 – $600

15. Prevalence & proportion prescribed by group of supplement

17. Prevalence for top 10 supplements

19. Factors associated with the use of dietary supplements

20. What Lit Review tells us • Factors established to have positive association with the use of dietary supplements • Female gender • High education level • High socio-economic status • Alcohol drinking • High physical activity • Non-obese / low BMI • Concern with healthy diet, vegetarians • Stressful lifestyle • Presence of a medical condition, medication use • Positive view of the potential health benefits of using supplements

21. What Lit Review tells us • Factors with contradictory reports on association with the use of dietary supplements • Age • Smoking • Self-perceived health status

22. Statistical tests used • To evaluate relationship between 2 qualitative variables • Chi-square test • Pearson chi-square & Fisher’s exact test for p values • Linear-by-linear association for trend • To evaluate relationship between a quantitative and a qualitative variable • Independent samples t-test & One-way analysis of variance (ANOVA) • For t-test, equal variances assumed or unassumed is used depending on p value from Levene’s test • Log transformation using ln (is done first if continuous variable is not normally distributed) • Results presented after re-conversion back to geometric mean & relative mean difference

23. Gender

24. Education level

25. Ethnic group • Ethnic group is not a significant factor affecting the use of dietary supplements in general • It becomes significant only when we stratify by specific supplement use

26. Ethnic group

27. Ethnic group

28. Household income per year

29. Household income per year

30. Smoking status

31. Confounding • We suspect gender to be a confounder for smoking status Smoking status Gender Use of supplement

32. Confounding

33. Confounding • After stratification by gender, using the Mantel-Haenszel ratio calculation, the adjusted PRR for smoking is 0.860, which is 12.3% different from the crude ratio of 0.766. • Since this difference is >10%, it could be significant. • Thus, gender is a potential confounder for smoking with regards to its effects on the use of supplements. • It could be investigated further by using multi-variate analysis.

34. Physical activity

35. View that diet provides sufficient nutrients

36. Diagnosed with chronic disease(s)

37. Diagnosed with chronic disease(s)

38. Diagnosed with chronic disease(s)

39. Specific chronic diseases diagnosed

40. Specific chronic diseases diagnosed

41. View that supplements are effective in improving health

42. View that there is scientific evidence for the use of supplements

43. View that supplements can have harmful side effects

44. Overview of characteristics & relation to use of supplement • Significantly related & shown in this ppt • Gender • Ethnic group • Education level • Household income • Smoking status • Physical activity • View that diet is sufficient • Presence of chronic disease • Diagnosed with Arthritis & Osteoporosis • View that supplements are effective • View that supplements have scientific evidence • View that supplements can have harmful side effects Green – shown by Lit Review to be positively related Yellow – inconclusive evidence from Lit Review

45. Overview of characteristics & relation to use of supplement • Not significantly related, but still shown in this ppt • Age • Body mass index • Healthy diet (fruits / vegetables) **to be confirmed again Green – shown by Lit Review to be positively related Yellow – inconclusive evidence from Lit Review

46. Overview of characteristics & relation to use of supplement • Not significantly related & not shown in this ppt at all • Marital status • Occupational status • Alcohol intake • Pack-years of smoking • Months since quit smoking • Dietary restriction • Diagnosed with other specific chronic disease • Pregnancy • Self-perceived health status • Stress in lifestyle • Adequacy of sleep Green – shown by Lit Review to be positively related Yellow – inconclusive evidence from Lit Review

47. Profile of a typical supplement user • Female • Has up to secondary or tertiary level education • Has high household income per year • Is a non-smoker • Exercises at least once a week • Views that diet does not provide sufficient nutrients • Is diagnosed with chronic disease(s), particularly Arthritis and Osteoporosis • Views that supplements are effective in improving health and that there is scientific evidence for their use

48. Not significant - Age

49. Not significant - Body mass index (BMI)

50. Healthy diet **not confirmed**