Epidemly and biostat - Assignment Example

The objective is to evaluate one or more new treatments for a disease or condition. Intervention trial therefore involves choosing a sample from the diseased people to investigate there rare disease and undertake a follow up condition. Q2. What statistical method(s) a researcher can use to determine if the mean body mass index of the population is the same for three groups of subjects (group1=diet restriction; group2=exercise; group3=none). (EACH IS TWO POINTS =TOTAL=SIX POINTS) Q3. Ŷ represents the predicted value of y calculated using the equation Ŷ = a + bx.

In the formula, SBP = 34 + 0.2 x; where x = value of postnatal age (hours) for the neonates ≤ 1,000 grams? What is the value of the intercept (a)? What is the value of the slope (b)? (TWO POINTS) Q5. An equation indicating that systolic blood pressure or SBP = 30 + 0.4x. If the value of x is postnatal age of 20 hours, what is the value for Ŷ or SBP for neonates ≤ 1,000 grams? Show your calculations. (TWO POINTS) Population attributable fraction is a statistic used to estimate the proportional reduction in average disease risk over a given time interval that would be achieved by eliminating the exposure of interest from the population while distribution of other risk factors in the population remain constant.

This means that 85% of the cases of a disease could be avoided if the factor causally related to increase risk is eliminated and that the distribution of other risk factors remains unchanged. Q9. The death rates from various conditions are often compared across geographic areas. These comparisons are usually based on directly age-standardized mortality rates. Which of the following best describes what is meant by an age-standardized rate created by the direct method? (Choose one best answer and provide rationale).

(TWO POINT) Q12. The strength of an association is one of the criteria for