Should I focus on clinical medicine or data science?

David S,

What are you most interested in?

Do you like treatements, diagnosis, and healing?

Do you like scientific methods, increasing efficiencies and or data mining?

Both are industries that will take much studying and much energy from your part but the real question is what are you interested in, where do you see yourself in ten years and what would you like to do in in this world?

I wish you the best on your journey.

Data science is integral to some medicine, the best route of combining the two would be to go for med school first. Med school requires more rote data retention, this is easier to accomplish at a younger age. Medical school is costly, incurring the debt earlier in life is better. By contrast code can be learned much more cheaply than medicine, even freely. You aren’t required to have certifications for most fields in code; I can’t speak for data science directly, but I still have faith this can be picked up quickly with minimal expenditures.

so if you are interested in medical data science, go to med school first.

You should do both. Unless you're interested in contributing to the space of statistical methods and data science research (e.g. developing better algorithms, proving optimality, etc) most people are interested in applying data science. Applied data science is more than just knowing methods and techniques, it requires deeply understanding the domain specificities and nuances of the problems you're trying to solve.

So if you're interested in clinical medicine which has many substantive research areas, you should study that and take quantitative methodology and data science classes along side it. There are many interesting spaces in in medicine and biology that apply data science.