Diagnostic utility of protein to creatinine ratio (P/C ratio) in spot urine sample within routine clinical practice

Figures & data

Figure 1. Reasons of diagnostic inaccuracy using 24-h urine collection [4–6].

Figure 2. Advantages and disadvantages of 24-h urine collection [4–6].

Table 1. Albuminuria categories (A1, A2, A3) and relationship among proteinuria measured by different tests. Modification based on [19].

	Units	Categories
		A1 Normal to mildly increased	A2 Moderately increased	A3 Severely increased
AER	mg/24h	<30	30–300	>300
PER	mg/24h	<150	150–500	>500
ACR	mg/mmol	<3	3–30	>30
	mg/g	<30	30–300	>300
P/C ratio	mg/mg	<0.15	0.15–0.50	>0.50
	mg/mmol	<15	15–50	>50
	mg/g	<150	150–500	>500
Urine dipstick test		Negative to trace	Trace to 1+	1+ or greater

ACR: albumin-creatinine ratio; AER: albumin excretion rate; P/C ratio: protein-creatinine ratio; PER: protein excretion rate.

Table 2. Limitations of methods used for urine protein and creatinine evaluation.

Protein evaluation methods	Limitations
Dry chemistry, semi-quantitative method Reaction with pyrocatechol violet-dye	Dedicated mainly to albumin High risk of false positive results in the case of: alkaline samples, samples with the presence of urease-positive bacteria alkalizing urine, when the patient takes the quinine derivatives
Turbidimetry Sulfosalicylic acid Trichloroacetic acid Benzethonium chloride Ammonium chloride	Lack of standardization of the method resulting from: using different precipitants with different concentrations lack of a constant reaction temperature no constant reaction time from the addition of a precipitating substance to the reading affected by turbidity of the samples or by xanthochromia
Dye-binding methods Pyrogallol red	Overestimated result in: the presence of high concentration of iron (II) ions hematuria the case of taking: acetaminophen (Paracetamol), certain antibiotics from the group of penicillin and aminoglycosides
Other methods Ponceau-S Coomassie Brilliant Blue G-250	Difficult to perform, requires decantation Incomplete precipitation of low molecular weight proteins by trichloroacetic acid
Creatinine evaluation methods	Limitations
Colorimetric method Enzymatic Jaffe	The analytical specificity, sensitivity and analytical precision is systematically better for the enzymatic assays compared to the Jaffe assays Picrate (Jaffe method) can also react with pseudochromogens: acetoacetate, pyruvate, ketoacids, proteins, glucose, ascorbic acid, bilirubin or even some drugs

Table 3. Pregnant proteinuria [80].

Pregnant proteinuria
1. Proteinuria should be pre-evaluated during routine urinalysis by means of a strip test Positive result if ≥1 + [∼300 mg/L (30 mg/dL)]* Negative result**
2.Proteinuria evaluation using the spot urine P/C ratio Abnormal result ≥30 mg/mmol (0.3 mg/mg)
3.Heavy proteinuria >5 g/day***

Note: Proteinuria is not required to recognize preeclampsia.

* Evaluate the P/C ratio.

** Further diagnosis of proteinuria with the P/C ratio is not necessary.

*** It is associated with a severe condition of the newborn.

Table 4. Urinary protein excretion in children. Modification based on [108,110].

Type of test	Age/Condition	Values
Spot urine P/C ratio	Children from 6 months to 2 years	>50 mg/mmol or >500 mg/g or >0.5 mg/mg
	Children >2 years	>20 mg/mmol or >200 mg/g or >0.2 mg/mg
	Nephrotic syndrome	>220 mg/mmol or >2200 mg/g or >2.2 mg/mg
Protein concentration in 24-h urine collection	Children <6 month of age	>8 mg/m^2/h or >0.24 g/1.73m^2/d
	Children >6 month of age	>4 mg/m^2/h or >0.15 g/1.73m^2/d
	Nephrotic syndrome	>40 mg/m^2/h or >3 g/1.73m^2/d
	Children Newborns	100–150 mg/m^2/d >0.3 g/m^2/d

Table 5. Limitations of the spot urine P/C ratio evaluation [5,21,29,33,39,45,54,92,93,101,113–116].

Reference	Limitations
[5]	Spot urine P/C ratio does not take into account protein excretion in the urine during the day and from day-to-day
[21]	Lack of correlation between spot urine P/C ratio and protein concentration evaluated in 24-hour urine collection, if daily protein excretion exceed 6 g/day and GFR <15 mL/min/1.73m^2
[92,93]	Spot urine P/C ratio result depends on ethnicity (lower values are observed in the African-Americans, because they excrete more creatinine to urine compared to Caucasians with similar height and weight)
[101]	Spot urine P/C ratio result depends on muscle mass, which indicates its limited use in children/patients with low muscle mass and severely undernourished (the risk of false positive results when the urine sample is excessively diluted or creatinine in the urine ≤2.65 mmol/L (30 mg/dL))
[54,113]	Poor or lack of correlation between spot urine P/C ratio and protein concentration in 24-hour urine collection in patients with minimal change disease or membranous nephropathy with nephrotic-range proteinuria
[114]	The protein concentration may be overestimated or underestimated, especially when urine creatinine levels are ≤3.45 mmol/L (39 mg/dL) or ≥5.48 mmol/L (62 mg/dL)
[33,115]	The spot urine P/C ratio may be overestimated at GFR levels ≤10 mL/1.73m^2
[29,39,45,116]	The diversity of methods used to assess protein and creatine concentration make the comparison of spot urine P/C ratio results between laboratories impossible

GFR: glomerular filtration rate; P/C ratio: protein-creatinine ratio.

Table 6. Key points in the evaluation of the spot urine P/C ratio in different states [5,10,12–17,21,27,33–37,54,55,60,61,63,65,67,70,72,79,82,84,86,87,89,90,94,96,97,99,103,108,110,113,115,117–130].

References	Key points
	Kidney disease
[16,33]	In patients with lower levels of GFR, especially those with CKD stage 5, urinary protein excretion may be overestimated, indicating spot urine P/C ratio results dependent on the GFR value
[21,54]	The spot urine P/C ratio stronger correlated with protein concentration in 24-h urine collection if the proteinuria ranged from 0.3–3.5 g/day (300–3449 mg/day) compared to patients with nephrotic syndrome >3.5 g/day (>3500 mg/day); no correlation was observed when the protein excretion exceeds 6 g/day
[34,60]	Spot urine P/C ratio is a precise, convenient and reliable method for estimating urinary protein excretion in patients after kidney transplantation, especially with low proteinuria
[61]	Verification of the P/C ratio by means of protein concentration in 24-h urine collection is needed before important diagnostic and therapeutic decisions e.g. Before biopsy or before the change of immunosuppressive agents
[17,21,27,54,55,113]	The evaluation of the P/C ratio in a single urine sample is a good alternative to 24-h urine collection for the assessment of proteinuria, especially in patients with renal insufficiency and with different types of glomerulonephritis (e.g. patients with immunoglobulin A nephropathy)
[118]	Spot urine P/C ratio was as useful as protein/day in predicting outcomes in chronic kidney disease patients and is more convenient for patients, clinicians, and laboratories
	Lupus nephritis (LN)
[67]	The patient with LN should be directly qualified for renal biopsy if the spot urine P/C ratio is >100 mg/mmol (1.0 mg/mg)
[65,117]	Clinical decisions in LN patients should not rely on the spot P/C ratio results, as they can yield false-positive or false-negative diagnoses of glomerulonephritis compared to 24-h urine collection results
[63,64,70,117]	Spot urine P/C ratio is both a screening test and proteinuria monitoring assay in patients with LN, if proteinuria exceeds 1 g/day
	Diabetic nephropathy
[10]	P/C ratio of 15 mg/mmol (0.15 mg/mg) predicted significant proteinuria in diabetic nephropathy (sensitivity 97%, specificity 74%)
[72]	P/C ratio of 30 mg/mmol (0.3 mg/mg) predicted significant proteinuria in diabetic nephropathy (sensitivity 81%, specificity 100%)
[119]	In diabetes mellitus protein evaluation in 24-h urine collection should be performed instead of the spot urine P/C ratio
	Hypertension
[35]	Spot urine P/C ratio of 80 mg/mmol (0.8 mg/mg) with 95% sensitivity predicted nephropathy in hypertensive patients
[36]	Spot urine P/C ratio should be used routinely as a screening test in all patients with hypertension duration >5 years
[13,79]	The relationship between the spot urine P/C ratio values >30 mg/mmol (0.3 mg/mg) and the presence of left ventricular hypertrophy in patients with second stage of primary hypertension was observed
	Preeclampsia
[90]	Spot urine P/C ratio should not be used to detect significant proteinuria in pregnant African-American women
[94]	Spot urine P/C ratio results were unsatisfactory to estimate proteinuria at different course of pregnancy, e.g. medical complication including: overweight, obesity, diabetes, and smoking, symptomatic or asymptomatic bacteriuria
[96]	Spot urine P/C ratio in a several-hour urine samples (4-h, 8-h, 12-h, daily/night sample) could be a good alternative to detect proteinuria in pregnant women with suspected preeclampsia, especially when there was insufficient time to 24-h urine collection
[97]	Spot urine P/C ratio of 30 mg/mmol (0.3 mg/mg) was unreliable for suspect preeclampsia in close proximity to delivery
[99]	In multiple pregnancies women the diagnosis of preeclampsia should be made on P/C ratio cutoff other than 30 mg/mmol (0.3 mg/mg)
[36,37,80,84,86, 87,89,90,103]	For the estimation of proteinuria in women at risk of preeclampsia different cutoff values of the spot urine P/C ratio were recommended: 20 mg/mmol (0.2 mg/mg); 21 mg/mmol (0.21 mg/mg); 33 mg/mmol (0.33 mg/mg); 36 mg/mmol (0.36 mg/mg); >40 mg/mmol (0.40 mg/mg);≥ 40 mg/mmol (0.40 mg/mg); 53 mg/mmol (0.53 mg/mg), however the most frequently recommended cutoff point was 30 mg/mmol (0.30 mg/mg)
[120]	Spot urine P/C ratio in preeclamptic women >900 mg/mmol (9.0 mg/mg) (∼9 g/day), or >500 mg/mmol (5.0 mg/mg) (∼5 g/day) in women over 35 years, was associated with a greatly increased probability of adverse maternal and fetal outcomes
[121]	Spot urine P/C ratio between 30–35 mg/mmol (0.30–0.35 mg/mg) is an optimal threshold value to detect proteinuria >0.3 g/day
[122]	Spot urine P/C ratio was highly predictive to detect proteinuria >1g/day and it could be used as a rapid, alternative test in preeclamptic women
[123]	Spot urine P/C ratio ≥75 mg/mmol (0.75 mg/mg) in normotensive pregnant women was sufficient to detect significant proteinuria
[124]	Spot urine P/C ratio is a better tool for estimation of proteinuria in preeclampsia than the dipstick test
	Myeloma kidney
[12]	Spot urine P/C ratio is a useful screening test for assessing proteinuria in the course of multiple myeloma, taking into consideration that the dipstick test does not detect Bence-Jones protein
	Children
[108,109]	In children the spot urine P/C ratio is a good alternative to 24-h urine collection for evaluation of proteinuria
	In physiology children <2 years of age should have the P/C ratio ≤50 mg/mmol (0.5 mg/mg), while >2 years of age the P/C ratio should be ≤20 mg/mmol (0.2 mg/mg)
	Type of sample
[14,15, 115,125,126]	NKF K/DOQI guidelines and other authors suggested that untimed (spot) urine samples should be used to detect and monitor proteinuria in children and adults; a first-morning sample is preferred, but when it is not available a random sample could be accepted taking into account that daily activity may affect the amount of excreted protein in the urine
[5,127]	The ability to use a random urine sample is an advantage of the P/C ratio evaluation
	Glomerular filtration rate
[16,21,33]	Spot urine P/C ratio results are influenced by the GFR: good correlation between spot urine P/C ratio and the protein excretion in 24-h urine collection was observed in patients with GFR in norm or slightly decreased; weak relationship was observed at GFR <15 mL/min/1.73m^2
	General
[56]	Spot urine P/C ratio is fast and simple method for the exclusion of significant proteinuria and may reduce the number of unnecessary 24-h urine collections the P/C ratio initially was validated to differentiate nephrotic from non-nephrotic proteinuria
[115]	Spot urine P/C ratio could be used as an alternative to urine protein evaluation in 24-h collection in patients with GFR >10 mL/min/1.73m^2
[119]	We still lacks recommendations which methods of urine protein and creatinine concentrations evaluation should be used to minimize interlaboratory differences
[54,90,128–130,135]	The use of spot urine P/C ratio is a convenient and competitively priced method in patients with proteinuria <3.5 g/day

CKD: chronic kidney disease; GFR: glomerular filtration rate; LN: lupus nephritis; NKF K/DOQI: National Kidney Foundation Kidney Disease Outcomes Quality Initiative; P/C ratio: protein-creatinine ratio.

Table 7. The utility of ACR, the spot urine P/C ratio and the protein/day evaluation in different clinical conditions [103,131–138].

Reference	Utility
[103]	Study analyzed the accuracy of quantitative assessments of the spot urine P/C ratio and ACR at different cutoffs in predicting severe preeclampsia compared to protein/day measurement in pregnant women with hypertension and suspected proteinuria. Authors conclude that in this group of patients proteinuria should be initially checked in dipstick screening test and if the result is positive, the ACR should be performed; in the case of ACR being unavailable an alternative should be the spot urine P/C ratio. The recommended cutoffs for clinically significant proteinuria should be 8 mg/mmol for ACR and 30 mg/mmol (0.3 mg/mg) for the spot urine P/C ratio. Authors do not recommendthe evaluation of protein/day in hypertensive pregnant women.
[131]	Authors conclude that annual screening for dip-stick proteinuria, followed by ACR or the spot urine P/C ratio confirmation, in addition to GFR measurement and treatment with ACEI or ARB for albuminuria or proteinuria is cost-effective for preventing ESRD or death in diabetic patients or in non-diabetic subjects who have hypertension or are aged > 60 years.
[132]	Highlights that there is no consensus regarding the utility of the ACR and the spot urine P/C ratio evaluation, e.g.: the UK CKD guidelines, Scottish Intercollegiate Guidelines Network and Caring for Australians with Renal Impairment Guidelines recommend the use of ACR for diabetic patients, while spot urine P/C ratio should be applied for non-diabetic CKD the Kidney Disease Quality Outcomes Initiative Guidelines recommend ACR, whereas spot urine P/C ratio may be use if the ACR is high >56.5–113 mg/mmol creatinine (500–1000 mg/g)
[133]	Study analyzed 117 spot urine samples to evaluate the relationship between ACR and the spot urine P/C ratio at the cutoffs recommended by the NICE guidance on CKD. Authors did not found discordant results between ACR and the spot urine P/C ratio at cutoffs recommended by NICE: 30 mg/mmol and 50 mg/mmol (0.50 mg/mg), , respectively.
[134]	Based on the literature review authors conclude that ACR might be recommended for the diabetic while the spot urine P/C ratio for the non-diabetic individuals.
[135]	Authors retrospectively analyzed 6842 patients results and found that: the relationship between ACR and the spot urine P/C ratio is non-linear the spot urine P/C ratio correlated more with protein/day as compared to ACR (r = 0.91, p < 0.001 and r = 0.84, p < 0.001, respectively). Moreover, in the urine protein range 0.3–1 g/day there was a significantly greater scatter with ACR. the difference between the spot urine P/C ratio and ACR is less in the ACEi/ARB-treated patients the spot urine P/C ratio is a more sensitive and specific test as compared to ACR for detection of significant proteinuria (>0.5 or >1 g/day) in unselected patients attending a hospital kidney department
[136]	Authors retrospectively analyzed 602 patients with established diagnosis of CKD and found that: ACR strongly, significantly correlated with the spot urine P/C ratio (r = 0.94, p < 0.001) at all albuminuria ranges; on the other hand at normal albuminuria range such correlation was not observed univariate and multivariate linear regression analysis found that similar clinical features were associated with both ACR and the spot urine P/C ratio
[137]	The study analyzed 438 patients with IgAN and showed that: ACR strongly, significantly correlated with the spot urine P/C ratio (r = 0.87, p < 0.001); however better correlation was observed at lower ranges of proteinuria (r = 0.87, p < 0.001) both, ACR and the spot urine P/C ratio correlated with protein/day (r = 0.71, p < 0.001 and r = 0.74, p < 0.001, respectively) ACR had better usefulness in predicting IgAN progression as compared to the spot urine P/C ratio and protein/day
[138]	The CKD in children study showed that there is no difference in the ability of ACR and the spot urine P/C ratio in predicting time to GFR decline of 50%

ACEi: angiotensin-converting-enzyme inhibitors; ACR: albumin to creatinine ratio; ARBs: angiotensin receptor blockers; CKD: Chronic Kidney Disease; GFR: glomerular filtration rate; IgAN: IgA nephropathy; NICE: National Institute for Health and Clinical Excellence.

Levin A, Stevens PE, Bilous RW. Kidney disease: Improving global outcomes (KDIGO) CKD work group. KDIGO 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Int Suppl. 2013;3:1–150.

 Web of Science ®Google Scholar

Brown MA, Magee LA, Kenny LC, et al. International Society for the Study of Hypertension in Pregnancy (ISSHP). The hypertensive disorders of pregnancy: ISSHP classification, diagnosis & management recommendations for international practice. Pregnancy Hypertens. 2018;13:291–310.

 PubMed Web of Science ®Google Scholar

Leung AK, Wong AH, Barg SS. Proteinuria in children: evaluation and differential diagnosis. Am Fam Physician. 2017;95(4):248–254.

 PubMed Web of Science ®Google Scholar

Leung AK, Wong AH. Proteinuria in children. Am Fam Physician. 2010;82(6):645–651.

 PubMed Web of Science ®Google Scholar

Patil P, Shah V, Shah B. Comparison of spot urine protein creatinine ratio with 24 hour urine protein for estimation of proteinuria. J Assoc Physicians India. 2014;62(5):406–410.

 PubMedGoogle Scholar

Ahmed PI, Islam MN, Alam MB, et al. Comparison of 24 hour urinary protein and spot urinary protein- creatinine ratio in the assessment of proteinuria in patients with glomerulonephritis. J Dhaka Med Coll. 2015;23(2):194–202.

 Google Scholar

Marshall T, Williams KM. Total protein determination in urine: elimination of a differential response between the coomassie blue and pyrogallol red protein dye-binding assays. Clin Chem. 2000;46(3):392–398.

 PubMed Web of Science ®Google Scholar

Ali A, Asif N, Yaqub S, et al. Spot urine protein: creatinine ratio versus 24 hour urine protein at various levels of GFR patients referred to a tertiary care hospital of Pakistan. J Pak Med Assoc. 2008;58(9):476–479.

 PubMedGoogle Scholar

Delanaye P, Cavalier E, Pottel H. Serum creatinine: not so simple! Nephron. 2017;136(4):302–308.

 PubMed Web of Science ®Google Scholar

Myers GL, Miller WG, Coresh J, et al. National Kidney Disease Education Program Laboratory Working Group. Recommendations for improving serum creatinine measurement: a report from the Laboratory Working Group of the National Kidney Disease Education Program. Clin Chem. 2006;52(1):5–18.

 PubMed Web of Science ®Google Scholar

Montero N, Soler MJ, Pascual MJ, et al. Correlation between the protein/creatinine ratio in spot urine and 24-hour urine protein. Nefrologia. 2012;32(4):494–501.

 PubMed Web of Science ®Google Scholar

Barr DB, Wilder LC, Caudill SP, et al. Urinary creatinine concentrations in the U.S. population: implications for urinary biologic monitoring measurements. Environ Health Perspect. 2005;113(2):192–200.

 PubMed Web of Science ®Google Scholar

Boeniger MF, Lowry LK, Rosenberg J. Interpretation of urine results used to assess chemical exposure with emphasis on creatinine adjustments: a review. Am Ind Hyg Assoc J. 1993;54(10):615–627.

 PubMed Web of Science ®Google Scholar

Cade TJ, de Crespigny PC, Nguyen T, et al. Should the spot albumin-to-creatinine ratio replace the spot protein-to-creatinine ratio as the primary screening tool for proteinuria in pregnancy? Pregnancy Hypertens. 2015;5(4):298–302.

 PubMed Web of Science ®Google Scholar

Kobayashi S, Amano H, Terawaki H, et al. Spot urine protein/creatinine ratio as a reliable estimate of 24-hour proteinuria in patients with immunoglobulin A nephropathy, but not membranous nephropathy. BMC Nephrol. 2019;20(1):306.

 PubMed Web of Science ®Google Scholar

Yang CY, Chen FA, Chen CF, et al. Diagnostic accuracy of urine protein/creatinine ratio is influenced by urine concentration. PLoS One. 2015;10(9):e0137460.

 PubMed Web of Science ®Google Scholar

Xin G, Wang M, Jiao LL, et al. Protein-to-creatinine ratio in spot urine samples as a predictor of quantitation of proteinuria. Clin Chim Acta. 2004;350(1–2):35–39.

 PubMed Web of Science ®Google Scholar

De Silva DA, Halstead AC, Côté AM, et al. Unexpected random urinary protein: creatinine ratio results-limitations of the pyrocatechol violet-dye method. BMC Pregnancy Childbirth. 2013;13(1):152.

 PubMedGoogle Scholar

Yadav BK, Adhikari S, Gyawali P, et al. Use of protein: creatinine ratio in a random spot urine sample for predicting significant proteinuria in diabetes mellitus. Nepal Med Coll J. 2010;12(2):100–105.

 PubMedGoogle Scholar

Lamb EJ, MacKenzie F, Stevens PE. How should proteinuria be detected and measured? Ann Clin Biochem. 2009;46(3):205–217.

 PubMed Web of Science ®Google Scholar

Jyoti MP, Rohit G, Monmoyuri MD. Comparison of spot urine protein-creatinine ratio with 24-hour urine protein in glomerular disease. IJHRMLP. 2017;03:19–21.

 Google Scholar

Talreja H, Akbari A, White CA, et al. Predicting kidney transplantation outcomes using proteinuria ascertained from spot urine samples versus timed urine collections. Am J Kidney Dis. 2014;64(6):962–968.

 PubMed Web of Science ®Google Scholar

Akbari A, Fergusson D, Kokolo MB, et al. Spot urine protein measurements in kidney transplantation: a systematic review of diagnostic accuracy. Nephrol Dial Transplant. 2014;29(4):919–926.

 PubMed Web of Science ®Google Scholar

Medina-Rosas J, Yap KS, Anderson M, et al. Utility of urinary protein-creatinine ratio and protein content in a 24-hour urine collection in systemic lupus erythematosus: a systematic review and meta-analysis. Arthritis Care Res (Hoboken). 2016;68(9):1310–1319.

 PubMed Web of Science ®Google Scholar

Birmingham DJ, Rovin BH, Shidham G, et al. Spot urine protein/creatinine ratios are unreliable estimates of 24 h proteinuria in most systemic lupus erythematosus nephritis flares. Kidney Int. 2007;72(7):865–870.

 PubMed Web of Science ®Google Scholar

Choi IA, Park JK, Lee EY, et al. Random spot urine protein to creatinine ratio is a reliable measure of proteinuria in lupus nephritis in Koreans. Clin Exp Rheumatol. 2013;31(4):584–588.

 PubMed Web of Science ®Google Scholar

Bertsias GK, Tektonidou M, Amoura Z, et al. Joint European league against rheumatism and European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis. Ann Rheum Dis. 2012;71(11):1771–1782.

 PubMed Web of Science ®Google Scholar

Biradar SB, Kallaganad GS, Rangappa M, et al. Correlation of spot urine protein-creatinine ratio with 24-hour urinary protein in type 2 diabetes mellitus patients: a cross sectional study. J Res Med Sci. 2011;16(5):634–639.

 PubMed Web of Science ®Google Scholar

Ravikumar P. A study on the prevalence of increased left ventricular mass and proteinuria in newly diagnosed hypertensive patients. IAIM. 2017;4(7):196–200.

 Google Scholar

Brown MA, Lindheimer MD, de Swiet M, et al. The classification and diagnosis of the hypertensive disorders of pregnancy: statement from the International Society for the Study of Hypertension in Pregnancy (ISSHP). Hypertens Pregnancy. 2001;20(1):IX–XIV.

 PubMed Web of Science ®Google Scholar

Lokhande MC, Jadhao AN. Role of random urinary protein to creatinine ratio in mild preeclampsi. NJMR. 2016;6(4):344–348.

 Google Scholar

Shreya G, Pranathi L, Kavitha V. Comparison of spot urine protein-creatinine ratio with 24-hour urine protein excretion in women with preeclampsia. IJIMS. 2015;2(1):55–59.

 Google Scholar

Rathindranath R, Teesta B, Proloy M. Evaluation of spot urine protein/creatinine ratio versus 24 hour urine protein in diagnosis of hypertensive disorders of pregnancy. IOSR-JDMS. 2015;14(2):44–47.

 Google Scholar

Kucukgoz Gulec U, Sucu M, Ozgunen FT, et al. Spot urine protein-to-creatinine ratio to predict the magnitude of 24-hour total proteinuria in preeclampsia of varying severity. J Obstet Gynaecol Can. 2017;39(10):854–860.

 PubMed Web of Science ®Google Scholar

Bhatti S, Cordina M, Penna L, et al. The effect of ethnicity on the performance of protein-creatinine ratio in the prediction of significant proteinuria in pregnancies at risk of or with established hypertension: an implementation audit and cost implications. Acta Obstet Gynecol Scand. 2018;97(5):598–607.

 PubMed Web of Science ®Google Scholar

Gaddy-Dubac L, Galvin SL, Gilmer S, et al. Spot urine protein: creatinine ratio versus 24-hour urine total protein to screen for preeclampsia. MAHEC Online J Res. 2012;1(1):2–7.

 Google Scholar

Haghighi L, Nasiri N, Ebrahimi A, et al. Predictive value of 4-, 8-, and 12-h urine protein and protein-to-creatinine ratio for detection of pre-eclampsia. Int J Gynaecol Obstet. 2016;134(1):62–65.

 PubMed Web of Science ®Google Scholar

Tanamai VW, Seagle BL, Yeh JY, et al. Urine protein/creatinine ratios during labor: a prospective observational study. PLoS One. 2016;11(8):e0160453.

 PubMed Web of Science ®Google Scholar

Osmundson SS1, Lafayette RA, Bowen RA, et al. Maternal proteinuria in twin compared with singleton pregnancies. Obstet Gynecol. 2014;124(2):332–337.

 PubMed Web of Science ®Google Scholar

Waugh J, Hooper R, Lamb E, et al. Spot protein-creatinine ratio and spot albumin-creatinine ratio in the assessment of pre-eclampsia: a diagnostic accuracy study with decision-analytic model-based economic evaluation and acceptability analysis. Health Technol Assess. 2017;21(61):1–90.

 Web of Science ®Google Scholar

Kristal B, Shasha SM, Labin L, et al. Estimation of quantitative proteinuria by using the protein-creatinine ratio in random urine samples. Am J Nephrol. 1988;8(3):198–203.

 PubMed Web of Science ®Google Scholar

Wahbeh AM. Spot urine protein-to-creatinine ratio compared with 24-hour urinary protein in patients with kidney transplant. Exp Clin Transplant. 2014;12(4):300–303.

 PubMed Web of Science ®Google Scholar

Chitalia VC, Kothari J, Wells EJ, et al. Cost-benefit analysis and prediction of 24-hour proteinuria from the spot urine protein-creatinine ratio. Clin Nephrol. 2001;55(6):436–447.

 PubMed Web of Science ®Google Scholar

Methven S, MacGregor MS, Traynor JP, et al. Comparison of urinary albumin and urinary total protein as predictors of patient outcomes in CKD. Am J Kidney Dis. 2011;57(1):21–28.

 PubMed Web of Science ®Google Scholar

Shidham G, Ayoub I, Birmingham D, et al. Limited reliability of the spot urine protein/creatinine ratio in the longitudinal evaluation of patients with lupus nephritis. Kidney Int Rep. 2018;3(5):1057–1063.

 PubMed Web of Science ®Google Scholar

Leung YY, Szeto CC, Tam LS, et al. Urine protein-to-creatinine ratio in an untimed urine collection is a reliable measure of proteinuria in lupus nephritis. Rheumatology (Oxford). 2006;46(4):649–652.

 PubMed Web of Science ®Google Scholar

Akin D, Ozmen S. An unresolved issue: the relationship between spot urine protein-to-creatinine ratio and 24-hour proteinuria. J Int Med Res. 2019;47(3):1179–1184.

 PubMed Web of Science ®Google Scholar

Ahsan A, Manna K, Yadav GS, et al. Protein creatinine index: a possible predictor of nephropathy in hypertensives, in Northern India. Clin Chim Acta. 2016;460:18–22.

 PubMed Web of Science ®Google Scholar

Ahsan A, Moinuddin A, Siddiqui AH, et al. Protein creatinine index: an alternative for screening nephropathy in hypertensives. J Clin Diagn Res. 2018;12(3):BC15–BC18.

 Web of Science ®Google Scholar

Forlemu A, Menanga A, Ashuntantang G, et al. Urinary protein excretion is associated with left ventricular hypertrophy in treatment-naïve hypertensive patients in an african hospital setting. Cardiorenal Med. 2013;3(1):57–62.

 PubMed Web of Science ®Google Scholar

Jan S, Javaid C, Firdous N. Diagnostic accuracy of spot urinary protein/creatinine ratio for proteinurea in pregnancy induced hypertension. Int J Reprod Contracept Obstet Gynecol. 2017;6(5):2083–2089.

 Google Scholar

Chan P, Brown M, Simpson JM, et al. Proteinuria in pre-eclampsia: how much matters? BJOG: An International Journal of O&G. 2005;112(3):280–285.

 PubMed Web of Science ®Google Scholar

Morris RK, Riley RD, Doug M, Deeks JJ, et al. Diagnostic accuracy of spot urinary protein and albumin to creatinine ratios for detection of significant proteinuria or adverse pregnancy outcome in patients with suspected pre-eclampsia: systematic review and meta-analysis. BMJ. 2012;345(jul09 1):e4342–e4342.

 PubMedGoogle Scholar

Demirci O, Kumru P, Arınkan A, et al. Spot protein/creatinine ratio in preeclampsia as an alternative for 24-hour urine protein. Balkan Med J. 2015;32(1):51–55.

 PubMed Web of Science ®Google Scholar

Baba Y, Ohkuchi A, Usui R, et al. Urinary protein-to-creatinine ratio indicative of significant proteinuria in normotensive pregnant women. J Obstet Gynaecol Res. 2016;42(7):784–788.

 PubMed Web of Science ®Google Scholar

Nipanal HV, Maurrya DK, Susmitha S, et al. Analysis of proteinuria estimation methods in hypertensive disorders of pregnancy. J Obstet Gynecol India. 2018;68(6):452–455.

 PubMed Web of Science ®Google Scholar

Wozney JL, Damluji AA, Ahmed F, Zangari M, et al. Estimation of daily proteinuria in patients with multiple myeloma by using the protein-to-creatinine ratio in random urine samples. Acta Haematol. 2010;123(4):226–229.

 PubMed Web of Science ®Google Scholar

Jang KM, Cho MH. Clinical approach to children with proteinuria. Child Kidney Dis. 2017;21(2):53–60.

 Google Scholar

National Kidney Foundation. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis. 2002;39(2 Suppl 1):1–266.

 PubMed Web of Science ®Google Scholar

Levey AS, Coresh J, Balk E, et al. National Kidney Foundation practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Ann Intern Med. 2003;139(2):137–147.

 PubMed Web of Science ®Google Scholar

Newman DJ, Pugia MJ, Lott JA, et al. Urinary protein and albumin excretion corrected by creatinine and specific gravity. Clin Chim Acta. 2000;294(1–2):139–155.

 PubMed Web of Science ®Google Scholar

Selvarajah V, Flynn R, Isles C. Comparison of estimated protein output and urine protein: creatinine ratio in first and second voids with 24-hour urine protein. Nephron Extra. 2011;1(1):235–241.

 PubMedGoogle Scholar

Naresh CN, Hayen A, Craig JC, et al. Day-to-day variability in spot urine protein-creatinine ratio measurements. Am J Kidney Dis. 2012;60(4):561–566.

 PubMed Web of Science ®Google Scholar

Price CP, Newall RG, Boyd JC. Use of protein:creatinine ratio measurements on random urine samples for prediction of significant proteinuria: a systematic review. Clin Chem. 2005;51(9):1577–1586.

 PubMed Web of Science ®Google Scholar

Methven S, MacGregor MS, Traynor JP, et al. Assessing proteinuria in chronic kidney disease: protein-creatinine ratio versus albumin-creatinine ratio. Nephrol Dial Transplant. 2010;25(9):2991–2996.

 PubMed Web of Science ®Google Scholar

Boulware LE, Jaar BG, Tarver-Carr ME, et al. Screening for proteinuria in US adults: a cost-effectiveness analysis. JAMA. 2003;290(23):3101–3114.

 PubMed Web of Science ®Google Scholar

McIntyre NJ, Taal MW. How to measure proteinuria? Curr Opin Nephrol Hypertens. 2008;17(6):600–603.

 PubMed Web of Science ®Google Scholar

Collier G, Greenan MC, Brady JJ, et al. A study of the relationship between albuminuria, proteinuria and urinary reagent strips. Ann Clin Biochem. 2009;46(3):247–249.

 PubMedGoogle Scholar

Guh JY. Proteinuria versus albuminuria in chronic kidney disease. Nephrology (Carlton). 2010;15(2):53–56.

 PubMedGoogle Scholar

Wu MT, Lam KK, Lee WC, Hsu KT, et al. Albuminuria, proteinuria, and urinary albumin to protein ratio in chronic kidney disease. J Clin Lab Anal. 2012;26(2):82–92.

 PubMed Web of Science ®Google Scholar

Zhao YF, Zhu L, Liu LJ, et al. Measures of urinary protein and albumin in the prediction of progression of IgA nephropathy. CJASN. 2016;11(6):947–955.

 PubMed Web of Science ®Google Scholar

Fuhrman DY, Schneider MF, Dell KM, et al. Albuminuria, proteinuria, and renal disease progression in children with CKD. CJASN. 2017;12(6):912–920.

 PubMed Web of Science ®Google Scholar