Diagnostic accuracy of self-administered urine glucose test strips as a diabetes screening tool in a low-resource setting in Cambodia.

OBJECTIVE: Screening for diabetes in low-resource countries is a growing challenge, necessitating tests that are resource and context appropriate. The aim of this study was to determine the diagnostic accuracy of a self-administered urine glucose test strip compared with alternative diabetes screening tools in a low-resource setting of Cambodia. DESIGN: Prospective cross-sectional study. SETTING: Members of the Borey Santepheap Community in Cambodia (Phnom Penh Municipality, District Dangkao, Commune Chom Chao). PARTICIPANTS: All households on randomly selected streets were invited to participate, and adults at least 18 years of age living in the study area were eligible for inclusion. OUTCOMES: The accuracy of self-administered urine glucose test strip positivity, Hemoglobin A1c (HbA1c)>6.5% and capillary fasting blood glucose (cFBG) measurement ≥126 mg/dL were assessed against a composite reference standard of cFBGmeasurement ≥200 mg/dL or venous blood glucose 2 hours after oral glucose tolerance test (OGTT) ≥200 mg/dL. RESULTS: Of the 1289 participants, 234 (18%) had diabetes based on either cFBG measurement (74, 32%) or the OGTT (160, 68%). The urine glucose test strip was 14% sensitive and 99% specific and failed to identify 201 individuals with diabetes while falsely identifying 7 without diabetes. Those missed by the urine glucose test strip had lower venous fasting blood glucose, lower venous blood glucose 2 hours after OGTT and lower HbA1c compared with those correctly diagnosed. CONCLUSIONS: Low cost, easy to use diabetes tools are essential for low-resource communities with minimal infrastructure. While the urine glucose test strip may identify persons with diabetes that might otherwise go undiagnosed in these settings, its poor sensitivity cannot be ignored. The massive burden of diabetes in low-resource settings demands improvements in test technologies.

Synergistic Tailoring of Electrostatic and Hydrophobic Interactions for Rapid and Specific Recognition of Lysophosphatidic Acid, an Early-Stage Ovarian Cancer Biomarker.

Early detection of ovarian cancer, the most lethal type of gynecologic cancer, can dramatically improve the efficacy of available treatment strategies. However, few screening tools exist for rapidly and effectively diagnosing ovarian cancer in early stages. Here, we present a facile "lock-key" strategy, based on rapid, specific detection of plasma lysophosphatidic acid (LPA, an early stage biomarker) with polydiacetylenes (PDAs)-based probe, for the early diagnosis of ovarian cancer. This strategy relies on specifically inserting LPA "key" into the PDAs "lock" through the synergistic electrostatic and hydrophobic interactions between them, leading to conformation transition of the PDA backbone with a concomitant blue-to-red color change. The detailed mechanism underlying the high selectivity of PDAs toward LPA is revealed by comprehensive theoretical calculation and experiments. Moreover, the level of LPA can be quantified in plasma samples from both mouse xenograft tumor models and patients with ovarian cancer. Impressively, this approach can be introduced into a portable point-of-care device to successfully distinguish the blood samples of patients with ovarian cancer from those of healthy people, with 100% accuracy. This work provides a valuable portable tool for early diagnosis of ovarian cancer and thus holds a great promise to dramatically improve the overall survival.

The Diagnosis of Urinary Tract Infection in Young Children (DUTY) Study Clinical Rule: Economic Evaluation.

OBJECTIVE: To estimate the cost-effectiveness of a two-step clinical rule using symptoms, signs and dipstick testing to guide the diagnosis and antibiotic treatment of urinary tract infection (UTI) in acutely unwell young children presenting to primary care. METHODS: Decision analytic model synthesising data from a multicentre, prospective cohort study (DUTY) and the wider literature to estimate the short-term and lifetime costs and healthcare outcomes (symptomatic days, recurrent UTI, quality adjusted life years) of eight diagnostic strategies. We compared GP clinical judgement with three strategies based on a 'coefficient score' combining seven symptoms and signs independently associated with UTI and four strategies based on weighted scores according to the presence/absence of five symptoms and signs. We compared dipstick testing versus laboratory culture in children at intermediate risk of UTI. RESULTS: Sampling, culture and antibiotic costs were lowest in high-specificity DUTY strategies (£1.22 and £1.08) compared to clinical judgement (£1.99). These strategies also approximately halved urine sampling (4.8% versus 9.1% in clinical judgement) without reducing sensitivity (58.2% versus 56.4%). Outcomes were very similar across all diagnostic strategies. High-specificity DUTY strategies were more cost-effective than clinical judgement in the short- (iNMB = £0.78 and £0.84) and long-term (iNMB =£2.31 and £2.50). Dipstick tests had poorer cost-effectiveness than laboratory culture in children at intermediate risk of UTI (iNMB = £-1.41). CONCLUSIONS: Compared to GPs' clinical judgement, high specificity clinical rules from the DUTY study could substantially reduce urine sampling, achieving lower costs and equivalent patient outcomes. Dipstick testing children for UTI is not cost-effective.

A comparison of ABAcard(®) p30 and RSID™-Semen test kits for forensic semen identification.

The screening and confirmatory tests available to a forensic laboratory allow evidence to be examined for the presence of bodily fluids. With the majority of evidence being submitted involving sexual assaults, it is important to have confirmatory tests for the identification of semen that are straightforward, quick, and reliable. The purpose of this study was to compare two commonly used semen identification kits utilized by forensic laboratories: ABAcard(®) p30 and Rapid Stain Identification of Human Semen (RSID™-Semen). These kits were assessed with aged semen stains, fresh and frozen post-vasectomy semen, post-coital samples collected on different substrates, post-vasectomy semen mixed with blood, saliva, and urine, a series of swabs collected at increasing time intervals after sexual intercourse, and multiple non-semen samples. The test kits were compared on the basis of sensitivity, specificity, and the cost and time effectiveness of each protocol. Overall, both semen identification tests performed well in the studies. Both kits proved specificity for identifying semen, however the ABAcard(®) p30 test surpassed the RSID™-Semen test in sensitivity, cost per test, and simplified test protocol.

Development of a manual self-assembled colloidal gold nanoparticle-immunochromatographic strip for rapid determination of human interferon-γ.

Interferons (IFNs) play a role in inhibition of tumor growth and participate in immunoreactions. Among IFNs, interferon-γ (IFNγ) is one of the most important therapeutic proteins and its immunodulation ability is better than that of other types. The objective of this study is to develop a manual self-assembled colloidal gold nanoparticle-immunochromatographic strip for human IFNγ using anti-human IFNγ polyclonal and monoclonal antibodies. Colloidal gold with a 25 nm diameter was made from chloroauric acid (HAuCl4), and labeled on anti-IFNγ mAbs as a chrominance reagent. A good linear relationship existed between the pixel intensity and the human IFNγ concentrations from 10-1000 ng mL(-1) in mouse serum and buffer, respectively, the regression equation was Y = 0.159logX + 0.0648, R(2) = 0.992 in mouse serum; Y = 0.294logX + 0.091, R(2) = 0.9969 in phosphate buffer by this proposed strip. Moreover, in the determination for mouse serum samples no cross-reaction occurred and the detection time was approximately 10 minutes. The shelf life of the strip was above 28 days at room temperature. The major advantages of the manual operation model were no expensive instruments and less reagents required. This proposed strip was highly specific, economic, convenient, and no machine was needed in clinical diagnosis.

The primary care perspective on routine urine dipstick screening to identify patients with albuminuria.

Proponents of routine urine dipstick screening to identify patients at risk for ESRD in the primary care setting have argued that urine dipsticks are inexpensive, low risk, acceptable to patients, and now, more accurate. Proponents believe that urine dipstick screening has the potential to improve outcomes for people with early disease and increase awareness of CKD. Most primary care physicians agree that populations who are at high risk for CKD should be tested and appropriately treated to decrease complications of ESRD. However, proponents of mass screening may not appreciate the challenges, limitations, and potential harms of screening. Urine dipstick testing does not meet all of the criteria for a good screening test. Screening the general population with urine dipsticks will generate many false positives--between 50% and 90% of positive tests--that will require follow-up, increase costs, and cause patient anxiety. Routine screening with urine dipsticks is not cost-effective on the order of $200,000 per quality-adjusted life year. Most importantly, there is little evidence that early identification of microalbuminuria in unselected patients influences outcomes of CKD. Without proof of effectiveness, overdiagnosis, a problem for even well established screening tests, is risked. Finally, no specialty society or preventive services group currently recommends general screening. Instead of screening, primary care physicians and nephrologists should work together to identify patients at high risk for ESRD and optimize management to improve outcomes for patients with CKD.

A cost-effectiveness analysis of screening urine dipsticks in well-child care.

OBJECTIVE: Despite data suggesting that routine urine screening for chronic kidney disease (CKD) has low diagnostic yield and the American Academy of Pediatrics 2007 recommendation to discontinue this screening, pediatricians may not have recognized this change. Because the new recommendation marks a major alteration in the practice guidelines, we sought to evaluate the cost-effectiveness of dipstick urinalysis for detection of CKD from the primary care practitioner's perspective. METHODS: Decision analysis was used to model a screening dipstick urinalysis strategy relative to a no-screening strategy. Data on the incidence of hematuria and proteinuria in children were derived from published reports of large cohorts of school-aged children. Direct costs were estimated from the perspective of the primary care practitioner. The measure of effectiveness was the rate of diagnoses of CKD. Cost-effectiveness was evaluated by using an incremental cost-effectiveness ratio. RESULTS: Expected costs and effectiveness for the no-screening strategy were 0 dollars because no resources were used and no cases of CKD were diagnosed. The screening strategy involved a cost per dipstick of 3.05 dollars. Accounting for both true-positive and false-positive initial screens, 14.2% of the patients required a second dipstick as per typical clinical care, bringing the expected cost of the screening strategy to 3.47 dollars per patient. In the screening strategy, 1 case of CKD was diagnosed per 800 screened, and the incremental cost-effectiveness ratio was 2779.50 dollars per case diagnosed. CONCLUSIONS: Urine dipstick is inexpensive, but it is a poor screening test for CKD and a cost-ineffective procedure for the primary care provider. These data support the change in the American Academy of Pediatrics guidelines on the use of screening dipstick urinalysis. Clinicians must consider the cost-effectiveness of preventive care procedures to make better use of available resources.

Comparison of one-year costs of type 2 diabetes treatment with insulin glargine or insulin detemir in a basal supported oral therapy (BOT) in Germany.

OBJECTIVE: A one-year cost analysis comparing basal insulin analogues glargine (IG, Lantus) versus detemir (ID, Levemir) in combination with oral antidiabetic drugs (basal supported oral therapy; BOT) in insulin naive Type 2 diabetes patients in Germany based on the results of a randomized controlled clinical trial (RCT). The trial demonstrated equivalent treatment efficacy. MATERIALS AND METHODS: Total direct diabetes treatment costs were estimated from the perspective of the German statutory health insurance (SHI) for the time horizon of one-year. Simulated resources included medication (insulin, oral antidiabetic drugs) and consumable items (needles, blood glucose test strips and lancets). Initial and final insulin doses per kg body weight and proportion of patients with once/twice daily insulin injection were taken from the above mentioned RCT. Unit costs were taken from official German price lists and sources. Deterministic-(DTA) and probabilistic sensitivity analyses (PSA) on resource use and unit costs were performed to test robustness of the results. RESULTS: Average annual treatment costs per patient (base case) were euro 849 for glargine and euro 1,334 for detemir resulting in cost savings of euro 486 per patient per year (36%). Costs of insulins were euro 469 (IG) and euro 746 (ID). Costs of consumable items amounted at euro 380 (IG) and euro 588 (ID) respectively. Sensitivity analyses confirmed the findings in favor of insulin glargine. PSA results found cost savings ranging from euro 429 to euro 608 (5th/95th percentiles). CONCLUSIONS: The current model estimated that insulin glargine was associated with lower annual treatment costs of euro 486 (36%) compared to the use of insulin detemir while the same glycemic control is expected to be achieved.

A cost-effective screening method for preoperative hyperglycemia.

INTRODUCTION: The preoperative encounter may offer a cost-effective opportunity for diabetes screening. METHODS: Three hundred forty-seven fasting patients had a preoperative glucose measurement determined from blood residue left on the IV needle, measured with an Accu-Chek glucometer (Roche Diagnostics, Indianapolis, IN). RESULTS: After excluding patients with a diabetes history, 4.0% had a glucose measurement between 100 and 125 mg/dL, at a cost of $14.22 per identification, and 1.2% had a glucose measurement more than 125 mg/dL, at a cost of $32.00 per identification. CONCLUSIONS: This preoperative blood glucose screening test was implemented at a cost of approximately one-tenth of current methods.

Benefit of urinalysis.

OBJECTIVE: In the pilot Iran school screening programme, the minimal cost of screening dipstick urinalysis in 1601 asymptomatic school children was determined. METHODS: The cost of screening dipstick urinalysis was calculated by reviewing the literature for the prevalence of asymptomatic proteinuria, hematuria, bacteriuria, and glucosuria determined by an initial dipstick urinalysis. The minimal cost utilizing data of 3 general physicians was calculated. Costs were determined by using current charge for supplies ordered to perform tests, charges for tests performed by a commercial laboratory, and the cost of a final evaluation by a pediatric nephrologist. RESULTS: 4.7% (76/1601) of patients were calculated to have an initial abnormal urinalysis. Upon retesting 1.37% (22/1601) of patients were calculated to have a persistent abnormality. The calculated cost was $167 to initially screen all 1601 patients with a dipstick urinalysis or $0.092 per patient. The calculated cost to evaluates the 22 patients with any persistent abnormality on repeat dipstick urinalysis was $0.02 or $0.001 per patient. This is the calculated cost for a single screening of 1601 asymptomatic pediatric patients. CONCLUSION: Multiple screening dipstick urinalysis in asymptomatic pediatric is costly and should be discontinued. We propose that a single screening dipstick urinalysis be obtained at school entry age, between 6 and 7 years, in all asymptomatic children.

Dipsticks and diagnostic algorithms in urinary tract infection: development and validation, randomised trial, economic analysis, observational cohort and qualitative study.

OBJECTIVES: To estimate clinical and dipstick predictors of infection and develop and test clinical scores; to compare management using clinical and dipstick scores with commonly used alternative strategies; to estimate the cost-effectiveness of each strategy; and to understand the natural history of urinary tract infection (UTI) and women's concerns about its presentation and management. DESIGN: There were six studies: (1) validation development for diagnostic clinical and dipstick scores; (2) validation of the scores developed; (3) observation of the natural history of UTI; (4) randomised controlled trial (RCT) of scores developed in study 1; (5) economic analysis of the RCT; (6) qualitative study of patients in the RCT. SETTING: Primary care. PARTICIPANTS: Women aged 17-70 with suspected UTI. INTERVENTIONS: Patients were randomised to five management approaches: empirical antibiotics; empirical delayed antibiotics; target antibiotics based on a higher symptom score; target antibiotics based on dipstick results; or target antibiotics based on a positive mid-stream specimen of urine (MSU). MAIN OUTCOME MEASURES: Antibiotic use, use of MSUs, rates of reconsultation and duration, and severity of symptoms. RESULTS: (1) 62.5% of women had confirmed UTI. Only nitrite, leucocyte esterase and blood independently predicted diagnosis of UTI. A dipstick rule--based on having nitrite or both leucocytes and blood--was moderately sensitive (77%) and specific (70%) [positive predictive value (PPV) 81%, negative predictive value (NPV) 65%]. A clinical rule--based on having two of urine cloudiness, offensive smell, reported moderately severe dysuria, moderately severe nocturia--was less sensitive (65%) (specificity 69%, PPV 77%, NPV 54%). (2) 66% of women had confirmed UTI. The predictive values of nitrite, leucocyte esterase and blood were confirmed. The dipstick rule was moderately sensitive (75%) but less specific (66%) (PPV 81%, NPV 57%). (3) Symptoms rated as moderately bad or worse lasted 3.25 days on average for infections sensitive to antibiotics; resistant infections lasted 56% longer, infections not treated with antibiotics 62% longer and symptoms associated with urethral syndrome 33% longer. Symptom duration was shorter if the doctor was perceived to be positive about prognosis, and longer with frequent somatic symptoms, previous history of cystitis, urinary frequency and more severe symptoms at baseline. (4) 66% of the MSU group had laboratory-confirmed UTI. Women suffered 3.5 days of moderately bad symptoms if they took antibiotics immediately but 4.8 days if they delayed taking antibiotics for 48 hours. Taking bicarbonate or cranberry juice had no effect. (5) The MSU group was more costly over 1 month but not over 1 year. Cost-effectiveness acceptability curves showed that for a value per day of moderately bad symptoms of over 10 pounds, the dipstick strategy is most likely to be cost-effective. (6) Fear of spread to the kidneys, blood in the urine, and the impact of symptoms on vocational and leisure activities were important triggers for seeking help. When patients are asked to delay taking antibiotics the uncomfortable and worrying journey from 'person to patient' needs to be acknowledged and the rationale behind delaying the antibiotics made clear. CONCLUSIONS: To achieve good symptom control and reduce antibiotic use clinicians should either offer a 48-hour delayed antibiotic prescription to be used at the patient's discretion or target antibiotic treatment by dipsticks (positive nitrite or positive leucocytes and blood) with the offer of a delayed prescription if dipstick results are negative.

Evaluation of the ARKRAY AUTION Eleven reflectometer in detecting microalbuminuria with AUTION Screen test strips and proteinuria with AUTION Sticks 10PA strips.

OBJECTIVE: Albumin/creatinine and protein/creatinine ratios were measured with the ARKRAY AUTION Eleven reflectometer using AUTION Screen and AUTION Sticks 10PA strips, respectively, against quantitative Siemens Advia reference procedures from 368 patient urines, as an evaluation of their applicability for use in points-of-care and small laboratories. MATERIAL AND METHODS: Direct reflectance measurements were utilized to estimate imprecision, as well as to suggest reclassification of ordinal scale categories into normoalbuminuria, microalbuminuria and macroalbuminuria groups (3.4 g/mol and 34 g/mol cut-off limits, corresponding to 30 mg/g and 300 mg/g creatinine in conventional units). RESULTS: Analytically, ordinal scale albumin/creatinine ratios agreed in 86% of cases with those obtained from Advia measurements, resulting in a kappa coefficient of 0.79. Protein/creatinine ratios of the AUTION Sticks 10PA strip were classified into three groups at limits of 11.3 g/mol and 56.6 g/mol (100 mg/g and 500 mg/g in conventional units), with an agreement of 77% and a kappa coefficient of 0.65 against Advia procedures. To optimize clinical outcomes, cut-off reflectances of ordinal scale categories of AUTION Eleven were adjusted. The clinical specificity of detecting an increased albumin/creatinine ratio was then increased from 81% to 95%, with clinical sensitivity kept at 88% at the 3.4 g/mol limit of the reference procedure. Clinical specificity of the albuminuria field alone (at a clinical sensitivity of 88%) was only 73%. Adjustments to cut-off reflectances of the reported categories for protein/creatinine ratios increased clinical specificity from 54% to 94%, while losing clinical sensitivity from 97% to 89% only, with an improved concordance of 83% and a kappa coefficient of 0.75 against Advia measurements. The combination to creatinine measurements improved clinical specificity compared to 50% by the protein field alone. In economic terms, it is estimated that population screening for microalbuminuria using the AUTION Eleven reflectometer is cheaper than by quantitative albumin/creatinine measurements alone, based on the incidence of end-stage renal disease of 90 patients/million/year at the Northern Ostrobothnia Hospital District.

[Population screening for urinary protein loss: a sensible action]. / Screenen van de bevolking op eiwitverlies in de urine: een zinnige actie.

In 2006, the Dutch Nierstichting (Kidney Foundation) provided people with urinary dipsticks to determine whether they suffered from urinary protein loss. It was suspected that 0.5% of adult inhabitants would have hidden renal disease. Within two weeks, more than one million people had applied to receive the dipsticks. They were advised to contact their general practitioner if they tested positive. Blockade of the renin-angiotensin-aldosterone system (RAAS) in subjects with known renal disease and proteinuria improves renal and cardiac survival. However, many patients currently develop end-stage renal disease without prior knowledge ofhaving chronic kidney disease. These patients can be detected by screening for proteinuria or albuminuria. Japanese studies showed that about 5% of the general population have positive dipstick tests. It is to be expected that about 1% will be truly macroalbuminuric and another 2-3% will be microalbuminuric. Macroalbuminuria is the consequence of manifest glomerular damage, while microalbuminuria is in most cases related to underlying diabetes or hypertension (which frequently are not yet diagnosed). In both conditions, treatment with RAAS blockade is indicated and is aimed at both cardiac and renal protection. There are arguments indicating that screening of the general population for urinary protein loss is cost-effective.

Evaluation of a programme for control of schistosoma haematobium infection in Yemen.

An intervention study was conducted in Khamir, north of Sana'a, for control of urinary schistosomiasis using chemotherapy and health education. The validity and cost-effectiveness of reagent strips as a rapid diagnostic tool to screen for Schistosoma haematobium infection was also assessed along with visible haematuria. Prevalence of S. haematobium infection 14 months post-intervention fell from 58.9% to 5.8% and frequency of heavy infection from 40.0% to 18.9%. Health education sessions resulted in significant decrease in the frequency of contact with water sources and greater adherence to preventive measures. Mass chemotherapy plus health education is a feasible and effective method for reducing S. haematobium infection in Yemen. Reagent strips and visible haematuria could be cost-effective in remote areas with limited access to health services.

Comparison of a urine chemistry analyser and microscopy, culture and sensitivity results to detect the presence of urinary tract infections in an elective orthopaedic population.

Currently elective orthopaedic patients require a microscopy and culture of urine (MSU) to be performed on admission. Between 70-80% of urine cultures are found to be negative for infection, making this practice costly and time consuming. The purpose of this study was to compare the accuracy of a dip stick urine chemistry analyser (Clinitek 50 machine) with a MSU, to detect the presence of nitrites and/or leukocytes in a group of elective orthopaedic surgical patients. methodology: Using a prospective cohort study design all elective orthopaedic patients who met the study criteria were invited to participate. In total 102 patients undergoing total hip or total knee replacement surgery participated. results: Results showed that the prevalence of urinary tract infections in patients undergoing total knee or hip surgery, was 14%. High specificity and negative predictive values for the detection of bacterial growth by dip stick urine chemical analysis were found, especially when either the presence of nitrites or leukocytes was used as an indicator. conclusion: This study has provided valuable baseline data on the accuracy of using photometry techniques as a screening measure, in the detection of UTI, in a sample of orthopaedic patients. While the Clinitek 50 dip stick urine chemistry analyser did not have high sensitivity in identifying those patients with a UTI, it was specific in identifying those patients who did not have an infection. Given the enormous cost in routine screening of these patients and the impact on nursing resources, use of this analyser could have potential nursing resource and financial benefits.

Visceral leishmaniasis in the Syrian Arab Republic: early detection using rK39.

Leishmaniasis causes significant morbidity and mortality in areas where it is endemic. A seroprevalence survey was conducted in 2 endemic villages in Daraa, Syrian Arab Republic, where 80 out of 345 children (23.2%) tested positive for visceral leishmaniasis (VL) using rK39 dipstick test. Only 10 cases were symptomatic (12.5%), and 27.5% were positive by ELISA test. All the sera (N = 138) obtained from the control village were negative. Of the rK39 initially positive cases, 52 had seroconverted to negative 9 months later, 55 remained ELISA negative, and none developed the full-blown disease. Being faster and less expensive than other diagnostic tests, rK39 is a rapid, sensitive and specific diagnostic tool for symptomatic cases of VL in remote areas with poor accessibility to health services.

Cost-effectiveness of urinary dipsticks to screen asymptomatic catheter-associated urinary infections in an intensive care unit.

OBJECTIVE: To assess the cost-effectiveness of urinary dipsticks (UDs) to screen asymptomatic catheterized patients for quantitative urine. DESIGN: Prospective comparison of UD with quantitative urine culture (QUC) (reference technique) and cost-effectiveness analysis performed from the hospital's perspective. SETTING: Medical intensive care unit (ICU) of the Besançon University Hospital (France). PATIENTS AND PARTICIPANTS: All consecutive, asymptomatic, catheterized patients. INTERVENTIONS: Urinary dipsticks (Multistix 8-SG) were analyzed by the reflectance spectrophotometric method (Clinitek 50). Sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of four combinations of the leukocyte (L) test pad and the nitrite (N) test pad were calculated: L and N, L or N, L alone and N alone. A micro-costing technique was used to determine the direct medical cost of each strategy. The calculated cost-effectiveness ratio was the incremental cost-effectiveness (ICE) ratio. MEASUREMENTS AND RESULTS: Three hundred thirty-nine urine samples taken from 144 patients were analyzed. The incidence of asymptomatic catheter-associated urinary tract infections (CAUTIs) was 31.3% (> or =10(5) organisms/ml). The L or N combination was the best detector of asymptomatic CAUTI: Se=87.2%, Sp=61.6%, PPV=30.6% and NPV=96.1%. The cost of QUC strategy and UD strategy was EUR 21.5 and EUR 12.6 per test, respectively. The ICE ratio of QUCs was EUR 69.5 per case of detected CAUTI. CONCLUSION: The UD is a cost-effective test for screening asymptomatic catheterized patients for quantitative urine culture in a medical ICU.

How effective are screening tests for microalbuminuria in random urine specimens?

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 random 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 standard" for presence of MAlb in random urine samples 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 samples from diabetic inpatients and outpatients 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 populations with prevalence rates of > or = 15% for overt nephropathy. The TProt/Cr R ratio would only be effective in populations 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 submitted to a central laboratory, thereby reducing laboratory workload.

Screening for ketonemia in patients with diabetes.

STUDY OBJECTIVES: To determine the sensitivity and specificity of the urine ketone dip test as a screening test for ketonemia in hyperglycemic patients and to compare the performance of the urine ketone dip test with the anion gap and serum bicarbonate level. METHODS: This was a prospective study conducted in an urban, university-affiliated public hospital emergency department. Inclusion criteria consisted of (1) patients with known diabetes and hyperglycemia (glucose level>200 mg/dL) and any complaint of illness, or (2) patients with hyperglycemia and symptoms of undiagnosed diabetes mellitus. Urine ketone dip test, serum ketone, and electrolyte levels were determined on all subjects. Sensitivity, specificity, and predictive values along with 95% confidence intervals (CIs) were calculated. RESULTS: The study group comprised 697 patients, including 98 patients with diabetic ketoacidosis (DKA) and 88 with diabetic ketosis (DK). The sensitivity, specificity, positive, and negative predictive values of the urine ketone dip test for the detection of DKA were 99% (95% CI 97% to 100%), 69% (95% CI 66% to 73%), 35% (95% CI 29% to 41%), and 100% (95% CI 99% to 100%), respectively. For DKA and DK, the sensitivity, specificity, positive, and negative predictive values of the urine ketone dip test were 95% (95% CI 90% to 97%), 80% (95% CI 76% to 83%), 63% (95% CI 57% to 69%) and 98% (95% CI 96% to 99%). The anion gap and serum bicarbonate level were less sensitive but more specific than the urine ketone dip test for the detection of DKA and DK. CONCLUSION: The urine ketone dip test has high sensitivity for detecting DKA and a high negative predictive value for excluding DKA in hyperglycemic patients with diabetes with any symptoms of illness. The urine ketone dip test is a better screening test for DKA and DK than the anion gap or serum bicarbonate.