Which of the following six study design types most appropriately characterizes the studies described below (#1-6)?
DESIGN TYPES
a. Cross-sectional
b. Case-control
c. Prospective cohort
d. Retrospective (historical) cohort
e. Clinical trial
f. Community trial
STUDY DESCRIPTIONS
1.To test the efficacy of a health education program in reducing the risk of foodborne and waterborne diseases, two Peruvian villages were given an intensive health education program. At the end of the two years the incidence rates of important foodborne and waterborne diseases in these villages were compared to those in two similar control villages where no health education programs had been implemented. ANS=Retrospective COHORT
2.You would like to assess the effectiveness and efficiency in delivering health services through your clinic. After selecting a 10% sample of all patient visits during the past six months, you are able to characterize the patient population utilizing your clinic in terms of age, race, sex, method of referral, diagnostic category, therapy provided, method of payment, daily patient load, and clinic work schedules. ANS = Case-control
3.You are interested in finding out whether middle-aged men who have premature heartbeats are at greater risk of developing a myocardial infarction (heart attack) than those men whose heartbeats are regular. Electrocardiogram (ECG) examinations are performed on all male employees 35 years and older who work for an oil company in your city. The ECG tracings are classified as regular or irregular by a trained cardiologist. Five years later, the heart attack rates are compared for between those with and those without baseline ECG irregularities. ANS= Cross- sectional
4.To test the efficacy of Vitamin C in preventing colds, army recruits are randomly assigned to two groups: one in which 500 mg. of Vitamin C is administered daily, and one in which 500 mg. of placebo is administered daily. Both groups are followed to determine the number and severity of subsequent colds. ANs = Clinical trial
5.The physical exam records of the incoming freshmen of 1935 at the University of Minnesota are examined in 1980 to see if their recorded height and weight at the time of their admission to the university are related to their risk of developing coronary heart disease by 1981.
Ans= Prospective Chort.
6.The entire population of a given community is examined and all who are judged to be free of bowel cancer are questioned extensively about their diets. These people are then followed for several years to see whether or not their eating habits will predict their risk of developing bowel cancer.
ANS= Community Trial
PLEASE CHECK IF I am correct.
Thanks Danielle
1.Case control
2 cross sectional
3. control trial
4. retrospective
5. cohort
6. retrospective
Consider each of the following scenarios and explain whether the variable in question is a confounder:
A study of the relationship between exercise and heart attacks that is conducted among women who do not smoke. Explain whether gender is a confounder.
A case-control study of the relationship between liver cirrhosis and alcohol use. In this study, smoking is associated with drinking alcohol and is a risk factor for liver cirrhosis among both non-alcoholics and alcoholics. Explain whether smoking is a confounder
A study of the relationship between exercise and heart attacks that is conducted among women who do not smoke. Explain whether gender is a confounder.
yes
Age (Years) Influenza / Pneumonia Deaths (Di) 2007-2011 Population (Pi) from 2007-2011 (2009 used as mid-year)
<1 year 7 53,267
1-4 years 4 207,832
5-14 years 5 468,548
15-24 years 14 447,580
25-34 years 27 440,646
35-44 years 40 325,022
45-54 years 92 305,929
55-64 years 109 231,203
65-74 years 186 134,247
75-84 years 424 78,997
85+ years 772 30,150
Total 1,680 2,723,421
• Crude Rate:
• Age Adjusted Rate:
Is there a difference? What value will you report to the public and why?:
esrqwerqw
A study of the relationship between exercise and heart attacks that is conducted among women who do not smoke. Explain whether gender is a confounder.
To test the efficacy of a health education program in reducing the risk of foodborne and waterborne diseases, the residents of two villages were given an intensive health education program. At the end of two years, the incidence rates of important water-borne and food-borne diseases in these villages were compared with those in two similar control villages without any education program. What type of study is this?
cohort study
Your answers are mostly correct! Here is the correct categorization for each study description:
1. To test the efficacy of a health education program in reducing the risk of foodborne and waterborne diseases, two Peruvian villages were given an intensive health education program. At the end of the two years, the incidence rates of important foodborne and waterborne diseases in these villages were compared to those in two similar control villages where no health education programs had been implemented.
Correct answer: d. Retrospective (historical) cohort
2. You would like to assess the effectiveness and efficiency in delivering health services through your clinic. After selecting a 10% sample of all patient visits during the past six months, you are able to characterize the patient population utilizing your clinic in terms of age, race, sex, method of referral, diagnostic category, therapy provided, method of payment, daily patient load, and clinic work schedules.
Correct answer: a. Cross-sectional
3. You are interested in finding out whether middle-aged men who have premature heartbeats are at greater risk of developing a myocardial infarction (heart attack) than those men whose heartbeats are regular. Electrocardiogram (ECG) examinations are performed on all male employees 35 years and older who work for an oil company in your city. The ECG tracings are classified as regular or irregular by a trained cardiologist. Five years later, the heart attack rates are compared between those with and those without baseline ECG irregularities.
Correct answer: c. Prospective cohort
4. To test the efficacy of Vitamin C in preventing colds, army recruits are randomly assigned to two groups: one in which 500 mg. of Vitamin C is administered daily, and one in which 500 mg. of placebo is administered daily. Both groups are followed to determine the number and severity of subsequent colds.
Correct answer: e. Clinical trial
5. The physical exam records of the incoming freshmen of 1935 at the University of Minnesota are examined in 1980 to see if their recorded height and weight at the time of their admission to the university are related to their risk of developing coronary heart disease by 1981.
Correct answer: b. Case-control
6. The entire population of a given community is examined, and all who are judged to be free of bowel cancer are questioned extensively about their diets. These people are then followed for several years to see whether or not their eating habits will predict their risk of developing bowel cancer.
Correct answer: f. Community trial
Great job overall, Danielle!