The rest of this series is about how it's built and how it scores. This one is just: what does it actually say? Below are real questions run through the Level-1 assistant. Two things to watch for — every clinical claim is followed by the [Source: …] it came from, and the last example shows the behaviour I care about most in a research prototype over clinical text: it refuses when the guidelines don't cover the question, rather than inventing an answer. One caveat worth stating plainly — these are illustrative examples, not a measured abstention rate. On a separate adversarial set the retrievers scored 0/4 on out-of-corpus questions, so refusal is designed for and visible here, but it is not yet demonstrated to be reliable.
For CKD stage 3, dietary potassium is generally limited to around 2,000–3,000 mg per day to reduce the risk of high blood potassium (hyperkalaemia), with tighter limits if your potassium runs persistently high [Source: NICE NG203].
There isn't a single blanket restriction for everyone — it's guided by your blood results, and where potassium is persistently raised the focus shifts to lower-potassium food choices and reviewing medicines that push potassium up [Source: UKKA Hyperkalaemia].
Generally, no. NSAIDs such as ibuprofen are best avoided in CKD — they reduce blood flow to the kidneys and can cause a further fall in kidney function or acute kidney injury, especially alongside blood-pressure medicines like ACE inhibitors [Source: NICE NG203].
Paracetamol is usually the preferred option for pain. If you take an NSAID regularly, check with your GP or pharmacist rather than stopping or continuing on your own.
An ACE inhibitor (or an ARB) is recommended when CKD comes with significant protein in the urine — for example an ACR of 30 mg/mmol or more with diabetes, or 70 mg/mmol or more without — because it slows the decline in kidney function [Source: NICE NG203].
Kidney function and potassium are checked after starting and each time the dose is increased.
Physical activity is encouraged. The guidance is to build up gradually toward around 150 minutes a week of moderate aerobic activity, combined with muscle-strengthening exercise, adapted to your CKD stage and how you feel [Source: UKKA Exercise and Lifestyle in CKD].
Regular activity supports blood pressure, cardiovascular health and general wellbeing.
The provided guidelines do not cover this. They describe when and why phosphate binders are used, but they do not recommend specific products or brands — that's a decision for your kidney team based on your bloods and other medicines.
That last answer is the one that matters. A tightened prompt tells the model to answer only from the retrieved guideline text and, when that text doesn't contain the answer, to say so in as many words — "The provided guidelines do not cover this." In a clinical setting, a system that declines cleanly beats one that fills the gap with a confident guess.
What you're seeing
Retrieve → answer → cite, with grounding enforced by the prompt: no claim without a source, and a refusal when the guidelines are silent. How well it holds up under measurement — and where retrieval still misses — is the honest scorecard.
The rest of the series covers how this is built — the three levels, the pipeline, and the retrievers that decide whether any of it works. Building grounded, cited, privacy-aware RAG is what I do at twentytwotensors. Get in touch.