title: Dipstick proteinuria as a screening strategy to identify rapid renal decline.
abstract: Rapid kidney function decline (RKFD) predicts cardiovascular morbidity and mortality, but serial assessment of estimated GFR (eGFR) is not cost-effective for the general population. Here, we evaluated the predictive value of albuminuria and three thresholds of dipstick proteinuria to identify RKFD in 2,574 participants in a community-based prospective cohort study with a median of 7 years follow-up. Median change in eGFR was -0.78 ml/min per 1.73 m(2) per year; with 8.5% experiencing RKFD, defined as a >5% annual eGFR decline from baseline. Of those with RKFD, 65% advanced to a new CKD stage compared with 19% of those without RKFD. Dipstick protein ≥ 1 g/L was a stronger predictor of RKFD than albuminuria. Overall, 2.5% screened positive for dipstick protein ≥ 1 g/L at baseline; one of every 2.6 patients would have RKFD if all were followed with serial eGFR measurement. Overall, the screening strategy correctly identified progression status for 90.8% of patients, mislabeled 1.5% as RKFD, and missed 7.7% with eventual RKFD. Among those with risk factors (cardiovascular disease, age >60, diabetes, or hypertension), the probability of identifying RKFD from serial eGFR measurements increased from 13 to 44% after incorporating dipstick protein (≥ 1 g/L threshold). In summary, inexpensive screening with urine dipstick should allow primary care physicians to follow fewer patients with serial eGFR assessment but still identify those with rapid decline of kidney function.
authors.affiliation: Division of Nephrology, Department of Medicine, University of Western Ontario, London, Ontario, Canada. William.Clark@lhsc.on.ca
authors.forename: William F
authors.initials: WF
authors.lastname: Clark
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Macnab
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Sontrop
authors.forename: Arsh K
authors.initials: AK
authors.lastname: Jain
authors.forename: Louise
authors.initials: L
authors.lastname: Moist
authors.forename: Marina
authors.initials: M
authors.lastname: Salvadori
authors.forename: Rita
authors.initials: R
authors.lastname: Suri
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005919:Glomerular Filtration Rate; D006801:Humans; D008403:Mass Screening; D008875:Middle Aged; D011320:Primary Health Care; D011446:Prospective Studies; D011507:Proteinuria / Q000175:diagnosis*; D011934:Reagent Strips; D051437:Renal Insufficiency / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D011934:Reagent Strips