What is Prevalence Ratio?
The Prevalence Ratio (also called Relative Risk for prevalence) compares the proportion of a condition (disease, characteristic) in two different groups. It indicates how much more (or less) prevalent the condition is in one group compared to another.
How to Use This Calculator
- Enter the number of cases in Group A (exposed group) and the total number of individuals in Group A
- Enter the number of cases in Group B (unexposed group) and the total number of individuals in Group B
- Click the "Calculate" button to compute the prevalence ratio
- The calculator will display the prevalence in both groups, the prevalence ratio, and an interpretation of the results
Interpreting Results
- PR > 1: Indicates that the condition is more prevalent in Group A than in Group B
- PR = 1: Indicates that the condition is equally prevalent in both groups
- PR < 1: Indicates that the condition is less prevalent in Group A than in Group B
Applications
Prevalence Ratios are commonly used in:
- Comparing disease rates between exposed and unexposed groups
- Assessing the effectiveness of interventions
- Epidemiological research to identify risk factors
- Comparing health outcomes across different populations
Example
Suppose you want to compare the prevalence of diabetes between people who exercise regularly (Group A) and those who do not (Group B):
- Group A: 30 cases out of 200 people
- Group B: 50 cases out of 300 people
- Prevalence A = 30/200 = 0.15
- Prevalence B = 50/300 = 0.1667
- PR = 0.15/0.1667 = 0.90
- Interpretation: Diabetes is 10% less prevalent in people who exercise regularly (PR = 0.90)