One of the big recurring arguments in pharma cost effectiveness modelling is whether to use databases and scripts with a proper statistical programming languages like R, or whether to stick with Excel / Sheets for our models. The advantages of proper languages are manifold, including—as you’ve pointed out—that you can probably use LLMs on them more successfully to audit and augment your code. However the advantage of spreadsheets is that they are extremely portable, meaning almost anyone can run them natively on their laptop and anyone can understand how they work if they want to change parameters. This matters a lot if transparency is a goal, and transparency is often such an overriding goal that we pick Excel over technically stronger languages. So I’d caution that in converting the existing models to databases / scripts you’re actually making implicit decisions about the nature and audience of the model far beyond just whether they are legible to LLMs or not.
I mention this because I’m about to get nerd-sniped by the problem and want to make sure the limitations of the approach are well understood before I get sucked into it!
We did a conversion from Excel to R in 2025, although not LLM assisted. It took about three months, which I would say was a disappointing but realistic downside-case timeline (we basically budgeted for two months and something complex came up). So if you’re finding you can get it done in weeks rather than months with an LLM you’re actually a long way ahead of the state of the art.