Dapagliflozin reduces the risk of kidney failure and heart failure in patients with chronic kidney disease. We aimed to investigate the effects of dapagliflozin on kidney, cardiovascular, and mortality outcomes according to presence or absence of type 2 diabetes and according to underlying cause of chronic kidney disease, reported as diabetic nephropathy, chronic glomerulonephritides, ischaemic or hypertensive chronic kidney disease, or chronic kidney disease of other or unknown cause.DAPA-CKD was a multicentre, double-blind, placebo-controlled, randomised trial done at 386 study sites in 21 countries, in which participants with a urinary albumin-to-creatinine ratio of 200-5000 mg/g and an estimated glomerular filtration rate (eGFR) of 25-75 mL/min per 1·73m2 were randomly assigned (1:1) to dapagliflozin 10 mg once daily or matching placebo, as an adjunct to standard care. The primary outcome was a composite of sustained decline in eGFR of at least 50%, end-stage kidney disease, or kidney-related or cardiovascular death. Secondary efficacy outcomes were a kidney-specific composite (the same as the primary outcome but excluding cardiovascular death), a composite of cardiovascular death or hospital admission for heart failure, and all-cause mortality. In this study, we conducted a prespecified subgroup analysis of the DAPA-CKD primary and secondary endpoints by presence or absence of type 2 diabetes and by aetiology of chronic kidney disease. DAPA-CKD is registered with ClinicalTrials.gov, NCT03036150.The study took place between Feb 2, 2017, and June 12, 2020. 4304 participants were randomly assigned (2152 to dapagliflozin and 2152 to placebo) and were followed up for a median of 2·4 years (IQR 2·0-2·7). Overall, 2906 (68%) participants had a diagnosis of type 2 diabetes, of whom 396 (14%) had chronic kidney disease ascribed to causes other than diabetic nephropathy. The relative risk reduction for the primary composite outcome with dapagliflozin was consistent in participants with type 2 diabetes (hazard ratio [HR] 0·64, 95% CI 0·52-0·79) and those without diabetes (0·50, 0·35-0·72; pinteraction=0·24). Similar findings were seen for the secondary outcomes: kidney-specific composite outcome (0·57 [0·45-0·73] vs 0·51 [0·34-0·75]; Pinteraction=0·57), cardiovascular death or hospital admission for heart failure (0·70 [0·53-0·92] vs 0·79 [0·40-1·55]; Pinteraction=0·78), and all-cause mortality (0·74 [0·56-0·98] vs 0·52 [0·29-0·93]; Pinteraction=0·25). The effect of dapagliflozin on the primary outcome was also consistent among patients with diabetic nephropathy (n=2510; HR 0·63, 95% CI 0·51-0·78), glomerulonephritides (n=695; 0·43, 0·26-0·71), ischaemic or hypertensive chronic kidney disease (n=687; 0·75, 0·44-1·26), and chronic kidney disease of other or unknown cause (n=412; 0·58, 0·29-1·19; Pinteraction=0·53), with similar consistency seen across the secondary outcomes. The proportions of participants in the dapagliflozin and placebo groups who had serious adverse events or discontinued study drug due to adverse events did not vary between those with and those without type 2 diabetes.Dapagliflozin reduces the risks of major adverse kidney and cardiovascular events and all-cause mortality in patients with diabetic and non-diabetic chronic kidney disease.AstraZeneca.