I am currently doing a study and as part of it, I have to develop a questionnaire with the following structure: Given a change in "Factor A" how will it affect "Factor B"?. I have realized that I have many factors (and therefore my questionnaire is quite long). Then, I would like to perform a statistical analysis to check if some of these factors are independent so I can eliminate some questions, and therefore reduce the questionnaire's size. For instance, if after an statistical analysis I obtain that Factor 1 and Factor 2 are independent i could eliminate 2 questions: (1) Given a change in "Factor 1" how will it affect "Factor 2"? and (2) Given a change in "Factor 2" how will it affect "Factor 1"?

To perform the analysis, I have data regarding factors presented in past accidents as follows:

- Accident 1: Factor 1, Factor 2, Factor 4, Factor "n"

- Accident 2: Factor 2, Factor 3, Factor "n"

...

Is there any statistical test that would allow me to determine if two factors (e.g. Factor 1 and Factor 3) are independent by considering how often they appear together in an accident?