1. By: Dr.Yossra K.Al-Robaiaay Assistant professor FICMS (FM)
STUDY DESIGN
By: Dr.Yossra K.Al-Robaiaay Assistant professor FICMS (FM)

2. STUDY DESIGN EXAMPLE PART 1
For each of the mentioned studies, identify:
The study type (design).
Useful features (advantages) & limitations (disadvantages) of the study.

3. STUDY DESIGN
EXAMPLE PART 1
1.A Gynecologist reported a newborn with small head and difficulty in breathing. Never having seen such a case before; she reported this case in her notebook. She described the relevant medical history, physical examination, laboratory tests, and clinical course of the patient; she did also photo-document the newborn.

4. STUDY DESIGN
2.You would like to improve the effectiveness & efficiency in delivering health services through a primary health center. After selecting a 20% sample of PHCC in Baghdad city, all patient visits during the past six months were collected, computed and analyzed. You characterized the patient population that were utilizing the centers in terms of age, sex, diagnostic category, therapy provided, method of payment and daily patient load, and clinic staff work schedules.

5. STUDY DESIGN
3.You are interested in finding out whether middle aged-men who have ectopic are at greater risk of developing a myocardial infarction than men with regular heartbeats. ECG is performed on all male office employees (35 years and older) who work for Basra oil companies. ECG tracings are classified into those with arrhythmias & those with regular heart rhythm. Repeated examinations are performed each year for 5 years to observe ECG changes. Employee medical health records are collected over the five-year period. At the conclusion of the study, myocardial infarction rates are calculated according to the ECG status at the beginning of the study.

6. STUDY DESIGN
4.It has been suggested that users of oral contraceptives are at greater risk of thromboembolic disease than those who do not use the drugs. By the ICD code of medical records, you are able to identity 100 women diagnosed as having thrombo-embolic disease during the past two years and a comparison group of 100 women who are similar to the cases with respect to age, race and parity but who do not have thrombo-embolic disease. A careful review of each woman’s medical chart revealed that a higher proportion of women with thrombo-embolism reported using oral contraceptives than did the control group.

7. STUDY DESIGN
5.A team of researchers conducted a study about mortality in Iraq before and after the 2003 war. During their house to house survey; they enquired about the number of cases of deaths in each household, cause of death, age and gender of the deceased, and the time of the event whether before or after 2003.

8. STUDY DESIGN
5.A team of researchers conducted a study about mortality in Iraq before and after the 2003 war. During their house to house survey; they enquired about the number of cases of deaths in each household, cause of death, age and gender of the deceased, and the time of the event whether before or after 2003.

9. STUDY DESIGN
6.You are planning to assess the burden of diseases on the health services and economy of Iraq during the last two years. You developed a checklist to collect information about the incidence of infectious diseases, incidence and prevalence of non communicable diseases (NCD), cancer and accidents (with some associated demographic variables) in ten governorates in Iraq to draw a line graph that depicts the pattern of diseases during this period.

10. STUDY DESIGN
7. A group of scientists proposed a project to examine a new protocol of cytotoxic drugs in the treatment of Acute lymphoblastic leukemia in children, they included two groups of leukemic children from the Blood Diseases Center, they put the first group under the new protocol, and keep the second group on the old one. They follow up both groups for six months and then check the prognosis of each.

11. STUDY DESIGN
EXAMPLE PART 2 What is the proposed design for each study? Discuss the advantages & limitations (disadvantages) of each study.

12. STUDY DESIGN EXAMPLE PART 2
1.You started to see an increasing alarming number of cases of Diabetes Mellitus in your country in the last few years:
After selecting an area in the neighborhood; you chose (by random) 100 houses, went to the families and inquire them about the presence of cases of hypertension. You also did ask about the presence of family history of hypertension, the presence of obesity among the family members, and the type of food they use to consume in addition to other demographic characteristics

13. STUDY DESIGN
2.A clinician (pediatrician) saw an abnormal finding in a new borne infant, the neonate has got an extra ear in the lower left side of his head:
Never having seen such a case before, the clinician reported this case by describing the relevant medical history, physical examination, vital signs, and checked for the presence of other congenital anomalies. He also searched for the presence of similar cases that may be registered before in the region

14. STUDY DESIGN
3. There are evidences that exposure of the people work in the plastic bags factory and the later development of lung cancer in those workers:
A group of medical students (4th year stage) decided to conduct a study to dig for this phenomenon. They have collected a sample of workers with Lung cancer and another sample of normal healthy workers, they inquire them about the period of exposure to plastic products. The investigators did also ask about history of smoking among those workers, finally, they compute the data and made a comparison between the two groups of workers regarding the exposure status.

15. STUDY DESIGN
4.You are interested to find if there is any relationship between the occurrence of heart attacks and practicing regular exercises.
You took 2 groups of men, in the first group the men were following a regular schedule of exercise on daily bases, while men in the second group never do any exercise. You followed the 2 groups up for 4 years and kept on doing ECG for them every month to find any ST-T changes as a marker of myocardial infarction. Then you collected the results, and do statistical analysis to calculate the incidence and RR.

16. STUDY DESIGN
EXAMPLE PART 3 For each of the following studies, identify: The study technique (design). Useful features (advantages) & limitations (disadvantages) of the study.

17. STUDY DESIGN
1. A physician observes a 35-years old man having an orange skin, & gastrointestinal abnormality (including changes in bowel habits).
Never having seen an orange man before, he feels obligated to report this case in his favorite medical journal. He described the relevant medical history, physical examination, laboratory tests, and clinical course of the patient. He speculated about the etiology or pathologic process of this unusual phenomenon.

18. STUDY DESIGN
2. You would like to improve the effectiveness & efficiency in delivering health services through Governmental hospitals. After selecting a 5% sample of all patient visits during the past six months you are able to characterize the patient population utilizing the health facility in terms of age, race, sex, method of referral, diagnostic category, therapy provided, method of payment, daily patient load, and clinic staff work schedules.

19. STUDY DESIGN
3. You are interested in finding out whether middle aged-men who have ectopic heart beat are at greater risk of developing a myocardial infarction than men with regular heartbeats.
ECG is performed on all male office employees (40 years or older) who work for Basrah oil companies. ECG tracings are classified into those with arrhythmias, & those with regular heart rhythm. Repeated examinations are performed each year for 5 years to observe ECG changes. Employee medical health records are collected over the five-year period. At the conclusion of the study, myocardial infarction rates are calculated according to the ECG status at the beginning of the study.

20. STUDY DESIGN
4. It has been suggested that users of oral contraceptives are at greater risk of thromboembolic disease than those who do not use the drugs.
By the ICD code of medical records, you are able to identity 200 women diagnosed as having thromboembolic disease during the past two years and a comparison group of 200 women who are similar to the cases with respect to age, race and parity but who do not have thromboembolic disease. A careful review of each woman’s medical chart reveals that a higher proportion of women with thromboembolism reported using oral contraceptives than did the comparison group.

21. Quiz:
1. Read the following passages. Identify the study design and list the advantages of each type. a. Questionnaires were mailed to every 10th person listed in the city telephone directory. Each person was asked to list age, sex, smoking habits, and respiratory symptoms during the preceding seven days. About 20% of the questionnaires were completed and returned. About 10% of respondents reported having upper respiratory symptoms. b. 1,500 employees of a major aircraft company were initially examined in 2011 and were classified by diagnostic criteria for coronary artery disease (CAD). New cases of CAD have been identified by examinations every three years and through death certificates. Attackrates in different subgroups have been computed.