1.If 3 out of 10 mammalian cell cultures exposed to ultraviolet (UV) radiation developed chromosomal abnormalities while 9 out of 10 mammalian cell cultures developed chromosomal abnormalities when exposed to UV radiation plus a common NSAID (nonsteroidal anti-inflammatory drug).
a)What type of study design?
b)Which parameter can determine? Calculate it.
c)Explain the results.
2.A study was carried out in Taiwan: a total of 128 histologically or cytologically confirmed cases of hepatocellular carcinoma and 384 controls without the disease were included in the study. Of the cases, 77% were carriers of the hepatitis B surface antigen (HbsAg) compared with only 28% of the controls (Chuanget al., 1992).
a)Formulate a possible hypothesis question
b)What type of study design?
c)Which parament can determine? Calculate it.
d)Explain the results
3.
Serum Carotenoids and Risk of Cervical Intraepithelial Neoplasia in Southwestern American Indian Women(Melissa A.Schiff,Ruth E.Patterson,Richard N.Baumgartner,MaryMasuk,Lindavan Asselt-King,Cosette M.WheelerandThomas M.Becker, Published November 2001,Cancer Epidemiology, Biomarkers & Prevention)
Abstract: «The objective of this research was to evaluate the association between serum carotenoids and cervical intraepithelial neoplasia (CIN) among Southwestern American Indian women. Cases were American Indian women with biopsy-proven CIN II/III cervical lesions (n= 81) diagnosed between November 1994 and October 1997. Controls were American Indian women from the same clinics with normal cervical epithelium (n= 160). All of the subjects underwent interviews and laboratory evaluations. Interviews evaluated demographic information, sexual history, and cigarette smoking. Serum concentrations of α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein/zeaxanthin were measured by high performance liquid chromatography. Cervical human papillomavirus infection was detected using a PCR-based test. Increasing levels of α-carotene, β-cryptoxanthin, and lutein/zeaxanthin were associated with decreasing risk of CIN II/III. In addition, the highest tertiles of β-cryptoxanthin (odds ratio = 0.39, 95% confidence interval = 0.17–0.91) and lutein/zeaxanthin (odds ratio = 0.40, 95% confidence interval = 0.17–0.95) were associated with the lowest risk of CIN. In conclusion, specially targeted intervention efforts to increase consumption of fruits and vegetables may protect Southwestern American Indian women from developing CIN».
a)Estimate the selection criteria for cases
b)Explain the results of the study using odds ratios
c)Determine the exposure and outcome
4.Which of the following health outcomes could be studied using a cross-sectional study design?Choose all that apply.
a)The prevalence of diabetes among adults in the United States in 2014
b)The prevalence of diabetes among all patients seen at a particular health clinic on one day in 2014
c)The number of new cases of diabetes diagnosed among at risk adults in the United States in 2014
d)The number of people in a population with diabetes who are obese and the number of people in a population with diabetes who are not obese, in the United States in 2014
5.A random sample of 1141 men and 1212 women aged 25-64 y (response rate 76%) completed a questionnaire and underwent a short examination in a clinic. Intake of beer, wine and spirits during a typical week, frequency of drinking, and a number of other factors were measured by a questionnaire. The present analyses are based on 891 men and 1098 women who were either nondrinkers or 'exclusive' beer drinkers (they did not drink any wine or spirits in a typical week). 500 men are beer drinkers and 325 men from this group have the obesity. 80 non-drinkers men are obese.
a)What type of study design?
b)Which parameter can determine? Calculate it.
c)Explain the results.
6.A randomized controlled trial is conducted to evaluate the incidence of diarrhea in 300 children with otitis media treated with a broad-spectrum antibiotic, amoxicillin + clavulanic acid, compared to amoxicillin. During the study, the participants and the investigator were not aware of the treatment allocation between experimental and control groups.
This study is:
A.Open-label
B.Single-blinded
C.Double-blinded
D.Non-blinded
The study design described above reduces:
A.Adverse drug reactions
B.Degree of bias
C.Compliance to the study protocol
D.Drop-out rate of participants
E.Duration of the study
7.The Physicians’ Health Study sought to examine the effects of beta-carotene and aspirin in preventing cardiovascular disease and cancer. The investigators enrolled and randomized approximately 22,000 male physicians in order to evaluate the independent and joint effects of the two treatments.
a)
Which study design best describes this trial?
A.Factorial design
B.Group allocation design
C.2 separate parallel trials, one for beta-carotene and one for aspirin
D.Crossover design
b)
Draw the scheme of appropriate trial
8.
Classify the following variables (specify the type of numerical and categorical data)?
Example:Numerical, Discrete:Number of cigarettes smoked per day.
_____ 1. Grade point average (on a scale of 0-4).
_____ 2. A person’s occupation
_____ 3. Marital status
_____ 4. A person’s height (in inches)
_____ 5. Number of children in a family
_____ 6. Type of newspaper read
_____ 7. Hair color
_____ 8. Pulse rate (beats per minute)
_____ 9. Size of a car’s gas tank (in liters)
_____ 10. Weight (in pounds)
_____ 11. Computer skill level (novice, intermediate, expert)
_____ 12. The number of words per minute that a person can type
_____ 13. The level of lead in water (milligrams per liter)
_____ 14. First letter of your last name
_____ 15. Serum cholesterol level
_____ 16. Outcome when tossing a coin (heads or tails)
_____ 17. Letter grade in a course (A, B, C, F)
_____ 18. Number of goals scored in a hockey game
_____ 19. Time (in hours)
_____ 20. Five years survival after chemotherapy
9.A pharmaceutical company develops a new drug to improve balance among the elderly. The new drug is recommended for individuals over 60 years of age to prevent unintentional falls. Investigators enroll 200 study participants in a randomized-controlled trial to evaluate the effectiveness of the drug at preventing falls. Half of the study participants are randomized to receive the new drug while the other half are randomized to receive a control treatment. At the end of a one-year follow-up period, the investigators determine whether the number of falls for each study participant was low (0-2 falls), moderate (3-5 falls), or high (6 or more falls) as a measurement of the primary outcome (unintentional falls). Which of the following best describes the primary outcome variable of this study?
A.Continuous
B.Dichotomous
C.Ordinal
D.Discrete
E.Nominal