We propose the following hypotheses:

• The use of herbal medicine is common among patients with chronic kidney disease in Réunion island.
• This use could influence the progression of kidney disease in these patients. To assess the primary inclusion criterion, patients will be easily identified by nephrologists through existing follow-up. The questionnaires will be administered after this early identification by the investigators at each center.

The primary evaluation criterion is straightforward: it aims to establish an overview of the use of herbal medicine in our patient population. This information is currently unavailable and remains crucial for measuring the extent of the issue. Our secondary criteria will involve more in-depth analysis of this use and an attempt to correlate the use of certain herbs with the rate of progression of kidney disease at one year.

We targeted patients with moderate to end-stage chronic kidney disease (KDIGO classification 3 to 5), which are the stages typically included in kidney disease studies. Furthermore, these patients are the most likely to experience a greater annual progression of their kidney disease, and the effect of herbs on this progression could be investigated. Transplant patients were not included because they are more aware of the risks of not using herbal medicine due to their use of immunosuppressants.

Inclusion Criteria:

Individual:

• Adult
• Resident of Réunion Island and planning to remain on the island for the year following enrollment
• Chronic Kidney Disease Stage 3, 4, or 5, not on dialysis
• Under the care of a nephrologist
• Able to complete a questionnaire
• Registered with social security

Exclusion Criteria:

Individual:

• Kidney transplant recipient
• Adult under guardianship or legal protection
• Pregnant or breastfeeding women, or women planning a pregnancy during the enrollment period