A RECENT study in the Annals of Internal Medicine reveals that too few patients with abnormal urine protein dipstick test results undergo the recommended follow-up albumin-to-creatinine ratio (ACR) testing to confirm albuminuria, a known risk factor for chronic kidney disease (CKD).
The research analysed electronic health records from over 1 million individuals who underwent dipstick urinalysis in 2021 across 33 US health systems. Dipstick urinalysis is a low-cost screening tool for detecting urine protein. Of the approximately 138,000 patients with abnormal results, only about 7% received subsequent ACR or protein-creatinine ratio (PCR) testing within the following year. Among those who did undergo further testing, nearly 43% were confirmed to have albuminuria, underscoring the importance of follow-up for early CKD identification.
Albuminuria, defined as an ACR of 30 mg/g or higher, indicates kidney damage and is a significant risk factor for CKD progression, cardiovascular disease, and increased mortality. Accurate assessment through ACR testing is particularly recommended for individuals with diabetes, hypertension, or pre-existing CKD, as it enables timely diagnosis and management, potentially slowing disease progression.
This study identified nonpregnant adults with at least one outpatient encounter and serum creatinine assessment, focusing on patients who had abnormal protein dipstick results (1+ or greater) without positive leukocyte esterase or nitrite results, which would suggest infection rather than kidney disease. Exclusions were made for patients with prior albuminuria diagnosis or ACR/PCR testing within six months before the test date.
Using Kaplan-Meier methods to estimate the follow-up, the researchers found that most individuals with abnormal dipstick results did not receive quantitative albuminuria testing within the study period. Further analyses considered dipstick proteinuria severity and the presence of diabetes, hypertension, or CKD, finding these factors may influence follow-up testing likelihood.
The findings highlight a critical gap in CKD screening practices and suggest that improving ACR testing adherence following abnormal dipstick results could facilitate earlier CKD detection and treatment, potentially improving patient outcomes. This underscores the need for increased awareness among healthcare providers regarding the importance of confirming abnormal dipstick results through quantitative testing.
Reference
Xu Y et al. Shortfalls in follow-up albuminuria quantification after an abnormal result on a urine protein dipstick test. Ann Intern Med. 2024;DOI:10.7326/ANNALS-24-00549.
