I am working on a project where I have built an episode file of nursing home stays (this was built with a DOW structure - up to 24 stays per episode). I have 3 files (hospitalizations (up to 23 per person), ER visits, and MDS assessments) which can be linked to the episode file. I would like to do repeated passes through the claims files based on (for example) a given diagnosis AND the closest date in terms of proximity to a given date on the episode file, attaching variables from the chosen claim to the episode file. It would be great to somehow do this with macro parameters and a DOW routine - but I'm having a hard time figuring out how to combine the two separate parameters (diag/MDS assessment type, date) into the DOW loop. Naturally, these files are extremely large. Any thoughts? TIA.