Rationale Dipstick proteinuria may be a sign of a renal disorder, false-positive or associated with acute disease, and consequently, transient in hospitalised patients.
Objective To assess (a) the prevalence of proteinuria in hospitalised patients; (b) its association with estimated glomerular filtration rate (eGFR), findings known to cause false-positive test results and indicators of acute disease and (c) the need for follow-up after discharge.
Setting and participants All patients who had a dipstick urinalysis on admission to medical wards of a 400-bed regional hospital in 2018–2019.
Outcome variable Proteinuria.
Independent variables (a) Other findings on dipstick urinalysis; (b) patients’ age, gender, presence of urinary catheter and eGFR and (c) white blood cell count (WBC) and fever.
Results Of 22 329 patients, 6609 (29.6%) had urinalysis. Of those, 2973 patients (45.0%) had proteinuria of ≥+1 (≥0.30 g/L). The variables independently associated with proteinuria were other dipstick findings known to cause false-positive test results, elevated WBC, fever on presentation, presence of a urethral catheter and a low eGFR. eGFR alone was a poor predictor of proteinuria (c-stat 0.62); however, addition of the remaining independent variables to the model significantly improved its predictive ability (c-stat 0.80).
Conclusions Dipstick proteinuria is common in hospitalised patients. Although weakly associated with eGFR, proteinuria is mainly associated with confounding factors that may result in false-positive test results. The need for follow-up of proteinuria after discharge has questionable clinical utility and its high frequency would entail a considerable cost.
- adult nephrology
- chronic renal failure
Data availability statement
Data are available upon reasonable request. Not applicable.
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Contributors All the authors contributed to the conceptualisation, methodology, writing, review and editing. PF performed the analysis. All authors have read and approved the present version of the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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