Background Chronic kidney disease (CKD) is a leading global public health problem, with a substantial burden on healthcare systems; decreased quality of life, and poor prognosis for patients. In Chile, there is limited data on CKD prevalence and its distribution across population subgroups that impedes effective decision-making in the healthcare sector. The objectives were to estimate the prevalence of CKD among Chilean adults and examine its associations with sociodemographic characteristics, health behaviours, and comorbidities.

Methods Analysis of cross-sectional data from the two most recent large, nationally-representative Chilean Health Surveys (ENS) 2009–10 and 2016–17. The participants were individuals aged 15+ years with serum creatine data (ENS 2009–10: n=4777; ENS 2016–17: n=5279). The primary outcome was reduced kidney function (CKD Stages 3a-5) based on estimated glomerular filtration rate (eGFR <60 mL/min/1.73 m²). Increased albuminuria (≥30 mg/g), the secondary outcome measure, was determined using the urine albumin-to-creatinine ratio (ACR) ascertained among adults aged 40+ years with diabetes and/or hypertension. Both outcomes were analysed using logistic regression and the combined two-survey dataset, with results summarised using odds ratios (OR). CKD prevalence (Stages 1–5) among adults aged 40+ years was estimated using an expanded definition including participants with a reduced eGFR or an eGFR of at least 60 mL/min/1.73 m² but increased albuminuria (Stages 1–2). Analyses were adjusted for non-response and complex survey design.

Results Overall, 3.0% (95% CI: 2.4–3.8%) of adults in ENS 2016–17 had reduced kidney function. After full adjustment, participants with hypertension (OR 2.12; 95% CI 1.08–4.16) and those with diabetes (OR 1.66; 1.04–2.65) had significantly higher odds of reduced kidney function. 15.5% (13.5–17.8%) of adults aged 40+ years with diabetes and/or hypertension had increased albuminuria in 2016–17. Being obese versus normal weight (OR 1.66; 1.08–2.54) and having both diabetes and hypertension versus diabetes alone (OR 2.30; 1.34–3.95) were significantly associated with higher odds of increased albuminuria in fully-adjusted analyses. At least 15.4% of all adults aged 40+ in ENS 2016–17 had CKD (Stages 1–5) according to the expanded definition, including 9.6% of adults with CKD Stages 1–2.

Conclusion There is a high prevalence of Chilean adults at CKD Stages 1–2 that should be considered in the prevention strategies and Chilean healthcare guidelines.