1. A. The number of exposed group is 349 (1200-851). B. The number of non-exposed group is 851. C. The study design is cohort study. D. The incidence of lung cancer is 200/349 = 0.573 for smokers and 121/851 = 0.142 for non-smokers. E. The relative risk of lung cancer is 4.03 (0.573/0.142) which indicates that smokers are 4 times more likely to develop lung cancer than non-smokers. | | Lung Cancer | No Lung Cancer | |---|---|---| | Smokers | 200 | 149 | | Non-Smokers | 121 | 730 | F. The risk difference of lung cancer is 0.431 (0.573-0.142) which indicates that smokers have a higher risk of developing lung cancer than non-smokers. 2. A. The study design of the researcher is cross-sectional study. B. The prevalence of diarrhea in under five children is 16.4% ⁹. C. | | Diarrhea | No Diarrhea | |---|---|---| | Unprotected Water Source | 295 | 420 | | Protected Water Source | 800 | 230 | The odds ratio is 2.14 (295x230)/(800x420). 3. A. The number of cases is 927. B. The number of controls is 1023. C. | | Early Sexual Initiation | No Early Sexual Initiation | |---|---|---| | Cervical Cancer | 600 | 327 | | Free Cervical Cancer | 2 | 1021 | The odds ratio is 292.5 (600x1021)/(327x2). Source: Conversation with Bing, 6/17/2023 (1) Prevalence and associated factors of diarrhea among under-five children .... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7041267/. (2) Epidemiology Of Study Design - StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK470342/. (3) Epidemiology Of Study Design - PubMed. https://pubmed.ncbi.nlm.nih.gov/29262004/. (4) Introduction to Epidemiological Studies - PubMed. https://pubmed.ncbi.nlm.nih.gov/29876887/. (5) Smoking as a risk factor for lung cancer in women and men: a systematic .... https://bmjopen.bmj.com/content/8/10/e021611. (6) Smoking as a risk factor for lung cancer in women and men: a systematic .... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6194454/. (7) Association of smoking and polygenic risk with the incidence of lung .... https://www.nature.com/articles/s41416-022-01736-3. (8) Diarrheal morbidity and predisposing factors among children under 5 .... https://tropmedhealth.biomedcentral.com/articles/10.1186/s41182-020-00253-4. (9) Socio-demographic and environmental factors associated with diarrhoeal .... https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-020-09981-y. (10) Diarrhoeal disease - World Health Organization (WHO). https://www.who.int/news-room/fact-sheets/detail/diarrhoeal-disease. (11) Prevalence and associated factors of diarrhea among under-five children .... https://www.frontiersin.org/articles/10.3389/fped.2022.890304/full.