Statistical significance testing
# Chi-squared test for contingency table from original data

Undertake a chi-squared test on a contingency table created from original data.

Undertake a chi-squared test on a contingency table created from original data.

Inputs are:

- the desired level of confidence in the estimate;
- the desired precision of the results; and
- two columns of data. The first column is observations on a single risk factor while the second column is corresponding observations of a disease (or other) outcome. Include a header row of column identifiers.

Outputs include:

- the table of observed counts, with row and column totals;
- a table of row proportions (each cell as a proportion of the corresponding row total), with row totals;
- chi-squared statistic, degrees of freedom and corresponding P-value; and
- a stacked bar chart of cell frequencies for each column category in each row category.

Additional outputs are included if there are only two columns of data (column variable is dichotomous) - table and graph of proportions (as a proportion of row total) and associated confidence limits for the first column in each row.