***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: The predictive value of r and om urine sample during outpatient visit to predict persistent microalbuminuria was studied in 76 Type 1 , insulin-dependent diabetic subjects , 61 Type 2 , non-insulin-dependent diabetic subjects , and 72 Type 2 , insulin-treated diabetic subjects . Seventy-six patients attended outpatient clinic during morning , and 133 during afternoon . Microalbuminuria was suspected if Urinary Albumin Excretion ( UAE ) exceeded 20 mg/l . All patients were hospitalized within 6 months following outpatient visit , and persistent microalbuminuria was assessed then if UAE was between 30 and 300 mg/24 h on 2 - 3 occasions in 3 urines sample s. Of these 209 subjects eighty-three were also screened with Microbumintest ( Ames-Bayer ) , a semi-quantitative method . Among the 209 subjects , 71 were positive both for microalbuminuria during outpatient visit and a persistent microalbuminuria during hospitalization : sensitivity 91.0 % , specificity 83.2 % , concordance 86.1 % , and positive predictive value 76.3 % ( chi-squared test : 191 ; p less than 10(-4 ) ) . Data were not different for subjects examined on morning , or on afternoon . Among the 83 subjects also screened with Microbumintest , 22 displayed both a positive reaction and a persistent microalbuminuria : sensitivity 76 % , specificity 81 % , concordance 80 % , and positive predictive value 69 % ( chi-squared test : 126 ; p less than 10(-4 ) ) . Both types of screening appeared equally effective during outpatient visit . Hence , a persistent microalbuminuria can be predicted during an outpatient visit in a diabetic clinic BACKGROUND The first step in the diagnosis of diabetic nephropathy is to measure albumin in a spot urine sample . The aim of this study was to assess the accuracy of urinary albumin concentration ( UAC ) , urinary albumin-to-creatinine ratio ( UACR ) , and the Micral-Test II  in a r and om urine specimen ( RUS ) for microalbuminuria screening in diabetes mellitus . METHODS Two hundred and seventy-eight patients collected 24 h timed urine specimens followed by RUS .  Albumin ( immunoturbidimetry ) and creatinine were measured in protein-negative ( Combur-Test ) urine sample s. Sample s were classified as normoalbuminuric [ 24 h urinary albumin excretion rate ( UAER ) < 20 microg/min ; n = 189 ] and microalbuminuric ( UAER = 20 - 199 microg/min ; n = 89 ) . Micral-Test II readings were performed in 130 RUS . Receiver operating characteristics ( ROC ) curves were constructed using UAER as the reference st and ard . RESULTS The areas under the ROC curves were similar for UAC ( 0.934+/-0.032 ) and UACR ( 0.920+/-0.035 ; P = 0.626 ) , but the Micral-Test II had lower accuracy to diagnose microalbuminuria ( area = 0.846+/-0.047 ) than UAC ( P = 0.014 ) . The first cutoff point with 100 % sensitivity for UAC was 14.4 mg/l ( specificity = 77.2 % ) , and 15.7 mg/g for UACR ( specificity = 73.0 % ) . Concerning the Micral-Test II , sensitivity and specificity for the 20 mg/l cutoff point were 90.0 and 46.0 % , respectively . The agreement between UAER and the Micral-Test II for microalbuminuria diagnosis was 55.8 % ( kappa = 0.22 ; P < 0.001 ) . The cost of diagnosing microalbuminuria was 1.74 dollars(UAC ) , 2.00 dollars ( UACR ) and 4.09 dollars ( Micral-Test II ) per patient . CONCLUSIONS Measurement of  UAC  in a RUS was the best choice for the diagnosis screening of microalbuminuria in diabetic patients , considering cost and accuracy BACKGROUND Accurate measurement of proteinuria is important in the diagnosis and management of chronic kidney disease ( CKD ) . The reference st and ard test , 24-hour urinary protein excretion , is inconvenient and vulnerable to collection errors .  Spot urine protein-creatinine ratio ( PCR )  is a convenient alternative and is in widespread use . However , day-to-day variability in PCR measurements has not been evaluated . STUDY DESIGN Prospect i ve cohort study of day-to-day variability in spot urine PCR measurement . SETTING & PARTICIPANTS Clinical ly stable out patients with CKD ( n = 145 ) attending a university hospital CKD clinic in Australia between July 2007 and April 2010 . INDEX TEST Spot urine PCR . OUTCOMES Spot PCR variability was assessed and repeatability limits were determined using fractional polynomials . MEASUREMENTS  Spot PCRs  were measured from urine sample s collected at 9:00 am on consecutive days and 24-hour urinary protein excretion was collected concurrently . RESULTS Paired results were analyzed from 145 patients : median age , 56 years ; 59 % men ; and median 24-hour urinary protein excretion , 0.7 ( range , 0.06 - 35.7 ) g/d .  Day-to-day variability was substantial and increased in absolute terms , but decreased in relative terms with increasing baseline PCR . For patients with a low baseline PCR ( 20 mg/mmol [ 177 mg/g ] ) , a change greater than ±160 % ( repeatability limits , 0 - 52 mg/mmol [ 0 - 460 mg/g ] ) is required to indicate a real change in proteinuria status with 95 % certainty , whereas for those with a high baseline PCR ( 200 mg/mmol [ 1,768 mg/g ] ) , a change of ±50 % ( decrease to < 100 mg/mmol [ < 884 mg/g ] or increase to > 300 mg/mmol [ > 2,652 mg/g ] ) represents significant change . LIMITATIONS These study results need to be replicated in other ethnic groups . CONCLUSIONS Changes in PCR observed in patients with CKD , ranging from complete resolution to doubling of PCR values , could be due to inherent biological variation and may not indicate a change in disease status . This should be borne in mind when using PCR in the diagnosis and management of CKD The effectiveness of four urine screening tests-microalbumin  ( MAlb )  , total protein ( TProt )  , total protein/creatinine ratio ( TProt/Cr R ) , and dipstick ( DPalb ) test for albumin-were evaluated for the detection of MAlb in r and om urine specimens . The following criteria were used to assess the effectiveness of each urine screening test : 100 % specificity ( no false positive results ) ; cost effectiveness ; rapidity and ease of performing the screening test ; and increased laboratory efficiency . A " gold st and ard " for presence of MAlb in r and om urine sample s was defined as a microalbumin/creatinine ratio ( MAlb/Cr R ) of > or = 30 mg/g . The least costly urine screening test was the DPalb , which , if assigned a value of 1.0 , allowed a cost ranking order for the screening tests-DPalb ( 1.0 ) < urine TProt ( 1.03 ) < urine TProt/Cr R ( 2.1 ) < urine MAlb ( 7.0 ) . Two hundred urine sample s from diabetic in patients and out patients were tested . Only two screening tests -- MAlb and DPalb -- achieved 100 % specificity without increasing laboratory costs ( small net savings ) , whereas the other two screening tests -- TProt and TProt/Cr R-only achieved 100 % specificity with increased laboratory costs . Theoretical prevalence rate analysis showed that urine MAlb screening would be effective at all prevalence rates for overt nephropathy . TProt and DPalb urine screening testing would be most effective in population s with prevalence rates of > or = 15 % for overt nephropathy . The TProt/Cr R ratio would only be effective in population s with prevalence rates of > or = 30 % . Of the four urine screening tests , only DPalb would significantly streamline the process of measuring urine MAlb . The dipstick test is inexpensive , easy and rapid to perform , does not delay measuring the ratio , since there is no wait for the screening test result , and can be used by referring laboratories to screen urine specimens before they are su bmi tted to a central laboratory , thereby reducing laboratory workload OBJECTIVE To evaluate single- sample urine collection s to determine their ability to screen patients for the presence of microalbuminuria . Microalbuminuria in patients with type I diabetes predicts the development of diabetic renal disease . RESEARCH DESIGN AND METHODS Cross-sectional analysis of single- sample urine collection techniques ( first morning void , r and om upright void ) and methods of albumin analysis ( RIA , reagent tablet ) were compared with conventional 24-h urine collection s ( RIA ) . The study included 94 patients ( 45 males , 49 females ; mean serum creatinine 88 μM ) with type I diabetes , selected from a screened population of 301 patients from the University Hospital Subspecialty Clinics . RESULTS A 24-hour urine collection RIA  analysis for albumin revealed 36 normal patients ( < 30 mg ) , 27 with microalbuminuria ( 30–300 mg ) , and 31 with albuminuria ( > 300 mg ) . R and om upright urine sample s were more sensitive ( RIA 89 % , tablets 78 % ) for the detection of microalbuminuria than first morning void specimens ( RIA 70 % , tablets 60 % ) . Specificity was > 80 % with both r and om and first morning voids . CONCLUSIONS Screening for microalbuminuria can be performed in the clinic by r and om upright single- sample urine collection s. When reagent tablets were used , these results are available immediately . Patients who screen positive should be confirmed by 24-h or other timed urine collection OBJECTIVE To assess the performance of measurements of urinary albumin concentration ( UAC ) and urinary albumin : creatinine ratio ( UACR ) in a diurnal r and om urine specimen ( RUS ) for the screening of diabetic nephropathy . RESEARCH DESIGN AND METHODS A total of 95 ambulatory NIDDM patients ( 49 women , ages 40–75 years ) collected 123 RUSs during the morning after completing a timed 24-h urine collection . Albumin was measured by immunoturbidimetry .  According to timed urinary albumin excretion rate ( UAER ) measured in the 24-h collection ( criterion st and ard ) , sample s were classified as normoalbuminuric ( UAER < 20 μg/min ; n = 54 ) , microalbuminuric ( UAER 20–200 μg/min ; n = 44 ) , and macroalbuminuric ( UAER > 200 μg/min ; n = 25 ) . The receiver operating characteristics ( ROC ) curve approach was used . The ROC curves of UAC and UACR in RUS for screening of microalbuminuria ( normo- and microalbuminuric sample s ; n = 98 ) and macroalbuminuria ( micro- and macroalbuminuric sample s ; n = 69 ) were plotted . RESULTS Spearman 's coefficients of correlation of 24-h UAER vs. UAC and UACR were 0.91 and 0.92 , respectively ( P < 0.001 ) . The calculated areas ( ± SE ) under the ROC curves to screen microalbuminuria for UAC ( 0.9766 ± 0.015 ) and UACR ( 0.9689 ± 0.014 ) were similar ( P > 0.05 ) as were the corresponding areas for macroalbuminuria ( 0.9868 ± 0.0094 and 0.9614 ± 0.0241 , respectively ; P > 0.05 ) . The first point with 100 % sensitivity and the point of intersection with a 100%-to-100 % diagonal for microalbuminuria were as follows : 16.9 and 33.6 mg/l for UAC and 15.0 and 26.8 mg/g for UACR ; for macroalbuminuria 174.0 and 296.2 mg/l for UAC and 116.0 and 334.3 mg/g for UACR , respectively . CONCLUSIONS Albumin measurements ( UAC and UACR ) in an RUS presented almost perfect accuracy for the screening of micro- and macroalbuminuria and UAC measured in an RUS is simpler and less expensive than UACR and UAER . It is suggested as a valid test for use in screening for diabetic nephropathy To assess the validity of  urine albumin concentration ( UAC ) and the urine albumin : creatine ratio ( UACR ) in a r and om urine specimen ( 
    Output:
    
The time point of urine collection did not affect the diagnostic performance of either test .
AND RELEVANCE The UAC and the ACR yielded high sensitivity and specificity for the detection of microalbuminuria .