How can I avoid errors using a complex snippet when I need to re-run the snippet because I want to change an initial variable?

Thank you Scott. Impressive.

I have a related problem, which I thought your above solution can be applied, however I cannot solve it. Hoping you guys can help.

I have generated a series of questions (each question represented by a single snippet - like above "How many family members have colon cancer") which my medical students use to examine patients. The purpose is for teaching at university and to standard medical history taking (also to ensure completeness and standardise the medical examination of a patient to a certain problem). Originally the questions were designed for a medically trained person but now I would like the questions to be answered directly by the patient (direct access and time saver). Most questions are easy "Yes" or "No" and can be easily reworded and reformatted BUT unfortunately there are 2 closely related questions (both very complex but similar snippets) that I need to amalgamate, but I just can't seem to do it.

The premise is, many patients take some form of a "Blood Thinner" to partially inhibit or prevent coagulation of the blood. There are 2 groups of these blood thinners, Anti-Platelet Agents and Anti-Coagulant Medication. The Anti-Platelet Agents are either (1) Low-dose aspirin (Cartia or Astrix) (2) Clopidogrel (Plavix or Iscover) (3) Low-dose aspirin + Clopidogrel (Co-Plavix) or (4) Dipyridamole (Persantin or Asasantin). The Anti-Coagulant Medication are (1) Warfarin (2) Apixaban (Eliquis) (3) Rivaroxaban (Xarelto) or (4) Dabigatran (Pradaxa). The 2 groups of drugs ( Anti-Platelet Agents and Anti-Coagulant Medication) are prescribed for 2 different set of reasons. Depending on what which drug you take and for which reason there a set guidelines to instruct the patient how to stop the medication before surgery/procedure and how to restart after the surgery/procedure. Patients can also take one drug from each group (ie an Anti-Platelet Agent as well as an Anti-Coagulant Medication) for 2 different reasons and therefore need separate guidelines for each medication.

For the Dr and medical student it is easy to keep the 2 questions separate (as I have done and will share at the end of this long-winded enquiry) BUT for patients it is not feasible to ask the question (1) Do you take an Anti-Platelet Agent? and (2) Do you take an Anti-Coagulant Medication? The patient doesn't know what this class of medications are.

What I would like to be able to do (using a simplified approach - as above) is to ask ONE question only -> Do you take any Blood Thinning Medication? which the patient will understand.

The patient may pick 1, 2 or 3 choices from a complete list of Blood Thinning medications -> (1) Low-dose aspirin (Cartia or Astrix) (2) Clopidogrel (Plavix or Iscover) (3) Low-dose aspirin + Clopidogrel (Co-Plavix) (4) Dipyridamole (Persantin or Asasantin) (5) Warfarin (6) Apixaban (Eliquis) (7) Rivaroxaban (Xarelto) or (8) Dabigatran (Pradaxa) and depending on the answer, be presented with a choice of Why the medication is prescribed? (set of reasons will vary depending on which group the drug belongs to Anti-Platelet Agents or Anti-Coagulant Medication, and then generate a predetermined guideline for each medication taken. I hope it isn't too confusing. I think going through the 2 snippets may make it easier.

I have shared the snippets that I would like to combine in a simplified way below.

Thanks if you can help.

George