Case-control analysis is a common statistical method used to compare two groups — typically, a "case" group (with the outcome of interest) and a "control" group (without the outcome). This analysis is frequently used in epidemiology to study risk factors associated with a disease. In MATLAB, case-control analysis usually involves odds ratio calculations, hypothesis testing, and potentially logistic regression.
Here's a general approach to conducting a basic case-control analysis in MATLAB:
Assume you have two groups (cases and controls) and a binary exposure variable (e.g., "exposed" vs. "not exposed").
Here’s an example dataset:
cases
: Number of cases (with the condition).controls
: Number of controls (without the condition).exposed_cases
: Number of cases exposed to the risk factor.not_exposed_cases
: Number of cases not exposed.exposed_controls
: Number of controls exposed.not_exposed_controls
: Number of controls not exposed.Example:
% Example data
exposed_cases = 50;
not_exposed_cases = 30;
exposed_controls = 20;
not_exposed_controls = 100;
The odds ratio (OR) is a measure of the association between exposure and outcome. The formula for OR is:
$$ \text{OR} = \frac{(exposed_cases \times not_exposed_controls)}{(not_exposed_cases \times exposed_controls)} $$
In MATLAB:
% Calculating the odds ratio
odds_ratio = (exposed_cases * not_exposed_controls) / (not_exposed_cases * exposed_controls);
disp(['Odds Ratio: ', num2str(odds_ratio)]);
To estimate a confidence interval for the odds ratio, use the following formula for a 95% confidence interval: