Screening for proteinuria in patients with lupus: A survey of practice preferences among American rheumatologists

Objective. Screening for proteinuria in patients with lupus requires a diagnostic method with adequate validity to detect early disease. Recent studies have called into question the validity of qualitative proteinuria measurements. We set out to assess if American rheumatologists have changed their practice preferences in response to these data. Methods. Using an online survey tool, we questioned practicing physicians, who were members of the American College of Rheumatology in 2005, about their demographic characteristics and preferred method to detect proteinuria in patients with known lupus. Results. In our survey, 64.6% of 473 respondents reported using qualitative urinalysis (dipstick) as the primary method of screening for proteinuria. The remaining 32.7% preferred quantitative measurements (spot protein to creatinine ratio 16.8%; 24-h protein 7.8%; microalbuminuria 4.1%; 24-h protein to creatinine ratio 4.1%). Rheumatologists in practice for more than 10 years were more likely than those in practice for less time to use a qualitative method. Although physicians using dipsticks were most likely to use 1+ as a cutoff for significant proteinuria, 28.5% report using a threshold of ≥ 2+. Conclusion. Despite recent reports describing the inadequacy of urine dipstick as a measurement for low-grade proteinuria, the majority of practicing rheumatologists are utilizing that method for screening in patients with lupus. Because early detection of lupus nephritis has implications for prevention of renal associated morbidity and mortality, these findings should prompt further investigation of the adequacy and role of urine dipstick as a screening tool for lupus.