Observational study designs could the same person serve as both a case and non-case/control in the same analysis

In which of the following observational study designs could the same person serve as both a case and non-case/control in the same analysis? Cohort study Case-control study Nested case control study

Case-cohort study C and D

The figure below shows results from a study examining the association between use of genital talc powder (exposure) and ovarian cancer (outcome) among women who had a hysterectomy or tubal ligation. The exposure is categorized by time of use in relation to the procedure. A combined menopausal status and hormone therapy variable (premenopausal, postmenopausal/never used HT, postmenopausal, ever used HT) is the "third factor" in this example. Examine the results carefully and answer the question that follows: TABLE 3. Effect of Tubal Ligation and Hysterectomy by Menopausal Status and Hormone Therapy on Association Between Genital Talc Use and Ovarian Cancer Premenopausal Postmenopausal, Never Used HT Postmenopausal, Ever Used HT Genital Tale Use Among Women Who Controls Cases Adjusted Controls Cases Adjusted" Controls Cases Adjusted" Had a Hysterectomy or Tubal Ligation" N(%) N(%) OR (95% CD) N(%) OR (95% CD) N(%) N(%) OR (95% CD) Never used 147 (79) 94 (71) 1.00 (referent) 139 (67) 113 (67) 1.00 (referent) 130 (77) 58 (48) 1.00 (referent) Used both before 26 (14) 17 (13) 0.99 (0.48, 2.06) 45 (22) 36 (21) 1.00 (0.58, 1.72) 21 (13) 40 (33) 5.85 (2.88, 11.9) and after Used before only 10 (5) 20 (15) 4.40 (1.73, 11.2) 20 (10) 16 (10) 0.99 (0.46, 2.10) 12 (7) 18 (15) 3.49 (1.39, 8.75) Used after only 3 (2) 1 (1) 0.33 (0.03, 3.60) 3 (1) 4 (2) 1.66 (0.34, 8.21) 5 (3) $ (4) 2.11 (0.49, 9.17)

Comparing adjusted ORs (95% CI) for different categories of talc usage among women of various menopausal statuses, which of the following statements is the most accurate? Menopause status modifies the association between use of talc and ovarian cancer regardless of the timing of talc usage Menopause status modifies the association between use of talc and ovarian cancer, but only for women who used talc before and after their procedure Menopause status does not modify the association between use of talc and ovarian cancer regardless of the timing of talc usage Menopause status confounds the association between use of talc and ovarian cancer regardless of the timing of talc usage

Question 18 0 / 4 pts Review the data in the table below and answer the question that follows. Stress Alcohol Risk Expected Risk Expected Incidence Level Use Difference Additive Ratio Multiplicative Low 0.126 Reference Reference |—– Low High 0.149 0.023 1.18 Low 0.164 0.038 1.30 High High 0.328 0.202 ? 2.60 ? What is the correct formula that would be used to calculate the expected multiplicative effect of high stress level and high alcohol use on the incidence of the outcome?