State the type of study design for each of the following studies. 1) A study inv

Question

State the type of study design for each of the following studies.

1) A study investigates the risk of exposure to secondhand smoke on childhood asthma. 5,000 children with asthma were matched to 20,000 controls using socio-economic status. Their parents were then asked about exposure to secondhand smoke.

2) A study compares the proportion of people in California who have “high” versus “low” intake of of omega-3 fatty acid consumption with the percentage of people who have high blood pressure in California.

3) A study examines the effect of acupuncture on post-traumatic stress disorder. Participants with PTSD were randomized to either receive acupuncture or cognitive behavioral therapy. After three months, PTSD symptoms were assessed.

4) A study assesses the effects of vitamin D supplementation on risk of type I diabetes. 15,000 children living in a Scandinavian country were classified as either receiving vitamin D supplements or not receiving vitamin D supplements. These children were followed for 20 years and were asked each year about whether or not they had developed type 1 diabetes.

Explanation / Answer

1 ans ) Patients with a certain outcome or disease and an appropriate group of controls without the outcome or disease are selected (usually with careful consideration of appropriate choice of controls, matching, etc) and then information is obtained on whether the subjects have been exposed to the factor under investigation.---

Case-Control Studies

2 ANS) An experimental comparison study in which participants are allocated to treatment/intervention or control/placebo groups using a random mechanism (see randomisation). Best for study the effect of an intervention.

---Randomised Controlled Trial

3 ANS) A study that examines the relationship between diseases (or other health-related characteristics) and other variables of interest as they exist in a defined population at one particular time (ie exposure and outcomes are both measured at the same time). Best for quantifying the prevalence of a disease or risk factor, and for quantifying the accuracy of a diagnostic test.

---- CROSS SECTIONAL STUDY SURVEY

4 ANS)

controlled trial where each study participant has both therapies, e.g, is randomised to treatment A first, at the crossover point they then start treatment B. Only relevant if the outcome is reversible with time, e.g, symptoms.

CROSSOVER DESIGN

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.