Hello everyone. I would like to trend the amount of substance used over a period of time for individuals using a particular service to see whether there is an increase in substance use over time or not. Also I would like to know whether these changes are associated with a cardiac problem or not. The amount of substance (y axis) is in ranges, hence it is not continuous, while the Y axis is time. Each subject has measures at several points and these timepoints are not consistent for all the participants. No comparison group.. The cardiac event is a dichotomous variable (Yes/No). My questions are: 1) What type of statistical analysis would be appropriate to trend the amount of substance used by individuals over the period of study, considering that the amount of substance use will be in ranges, not a continuous variable. 2) What analysis can I do for the 2nd part to test whether there is an association with cardiac problem? I have been looking for research papers that may have done analysis of this type but I have not found yet. Any advice? If anyone has a resource link or research paper link that could help, that would be helpful in addition to the responses that I get from this forum. Thanks.
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