Association of Albuminuria Levels With the Prescription of Renin-Angiotensin System Blockade

Multiple clinical guidelines recommend an ACE (angiotensin-converting enzyme) inhibitor or angiotensin II receptor blocker (ARB) in patients with elevated albuminuria, which can be measured through urine albumin-to-creatinine ratio (ACR), protein-to-creatinine ratio, or dipstick. However, how albuminuria test results relate to the prescription of ACE inhibitor/ARB is uncertain. We identified individuals with an ACR measurement between January 1, 2004, and June 30, 2018, and no contraindications or allergy to ACE inhibitor/ARB. We performed multivariable logistic regression analyses to evaluate the association between ACR level and prescription of ACE inhibitor/ARB within 6 months after the test. We applied similar methods to investigate the association of protein-to-creatinine ratio and dipstick measurement results with the prescription of ACE inhibitor/ARB. Among 67 237 individuals with an ACR measurement, 47.7% were already taking an ACE inhibitor or ARB at the time of first ACR measurement. Among the 35 138 individuals who were not on ACE inhibitor/ARB, those with higher ACR levels were more likely to be prescribed ACE inhibitor/ARB in the following 6 months, with steep increases in prescriptions until ACR 300 mg/g, after which the association plateaued. The majority (80.9%) of ACE inhibitor/ARB prescriptions were made by family medicine and internal medicine. A similar pattern held in the cohorts tested by protein-to-creatinine ratio and dipstick measurement. Our study provides evidence that albuminuria test results change patient care, suggesting that adherence to albuminuria testing is a key step in optimal medical management.