Understanding Risk Ratio Calculation
The Risk Ratio (RR), also known as the Relative Risk, measures how much the risk of an event (like a disease) is increased or decreased in an exposed group compared to a non-exposed group.
Risk Ratio Definition
It is calculated as the ratio of the incidence of the disease in the exposed group to the incidence of the disease in the non-exposed group.
- Incidence in Exposed (Ie): The proportion or rate of new disease cases among individuals who were exposed to a potential risk factor.
- Incidence in Non-Exposed (Ine): The proportion or rate of new disease cases among individuals who were not exposed to the risk factor.
Risk Ratio Formula
The formula is represented using LaTeX as:
$ \text{Risk Ratio (RR)} = \frac{I_e}{I_{ne}} $
Why Other Options Are Incorrect
- Option 2 is incorrect because it represents the inverse of the Risk Ratio.
- Option 3 describes the Risk Difference (RD) or Absolute Risk Reduction, calculated as $ \text{RD} = I_e - I_{ne} $.
- Option 4 describes the Odds Ratio (OR), which is the ratio of odds, not incidence rates.
Therefore, the ratio of the incidence of the disease among exposed and the incidence among non-exposed correctly represents the Risk Ratio.
Important Questions from Statistics
Methods of presentation of data are:
Consider 35 i.i.d. observations X1, X2, ...., X15 and Y1, Y2, ..., Y20. Let R be the Wilcoxon's rank sum statistic based on the ranks of the X' s in the combined sample. Then the expected value of R is
Let I, J > 5. Consider two-way ANOVA, where the observations satisfy the linear model
yij = α + βi + γj + εij, 1 ≤ i ≤ I, 1 ≤ j ≤ J
E(εij) = 0, Var(εij) = σ2, \(\sum_{i=1}^{!} β_i=\sum_{j=1}^j γ_j=0 .\)
In this set - up
Let X1,X2,...,Xn be a random sample from exponential distribution with mean θ. Which of the following is NOT a sufficient statistic for θ?
A newly developed algorithm for random number generation needs to be tested. The first step is to check whether the sequence of numbers generated can be considered a random sample from the uniform distribution on the interval (0, 1). Which of the following is an appropriate nonparametric test?
