Oncological monitoring after transanal total mesorectal excision (TaTME) for rectal neoplasia

BACKGROUND

The surgical treatment of choice for rectal neoplasia is total mesorectal excision (TME). The transanal approach enables a better approach in male and obese patients and/or those with a narrow pelvis and in patients with small tumors. Short-term results are comparable with those for laparoscopy or the open approach, but the medium- and long-term oncological data are sparse. The aim of the present study was to evaluate our early experience with transanal TME (TaTME).

METHODS

This was a retrospective study conducted on patients who underwent TaTME at our center between August 2013 and April 2017 with a follow-up ≥ 3 years. Histopathology, complications, mortality, neoplastic recurrence and disease-free survival were analyzed.

RESULTS

One hundred patients (68 men and 32 women,, median age 66.8 years [range 29.6-91.2 years]) were included. There were 67 T3 cases (67%) with 74 N0 cases (74%), the mesorectal quality was graded optimal for 87.6% and only 2 cases of radial margin involvement were detected (2%). The median follow-up period was 47.6 months (range 11.8-78.9 months). Eighteen cases of recurrence were diagnosed, of which 3 (3%) recurred locally with an average disease-free period of 43.1 months. Overall survival was 80% and mortality due to progression of disease was 13%.

CONCLUSIONS

TaTME is a safe surgical procedure with surgical, anatomopathological and oncological results at 3 years (medium-term) comparable with those for the laparoscopic and open approaches. Better monitoring is required with studies of the long-term functional and quality of life outcomes, i.e., at 5 or 10 years.

Impact of Blood Glucose Monitoring System Accuracy on Clinical Decision Making for Diabetes Management

BACKGROUND

The accuracy of blood glucose monitoring systems (BGMS) is crucial for the safe and effective management of diabetes mellitus. Despite standardization of accuracy assessment procedures and requirements, various studies have shown that the accuracy of BGMS on the market can vary considerably. This article therefore provides health care professionals and users with an intuitive illustration of the impact of BGMS accuracy on clinical decision making.

MATERIAL AND METHODS

Several hypothetical patient scenarios based on blood glucose (BG) levels in the low, normal, and high BG range are devised. Using data from a recent BGMS accuracy study, a method for calculating the expected range of BG readings from four examined BGMS at the selected BG levels is introduced. Based on these ranges, it is illustrated how clinical decisions and subsequent outcomes of the hypothetical patients are affected by the expected inaccuracies of the BGMS.

RESULTS

The range of expected BGMS readings for the same true BG level can vary considerably between different BGMS. The discussion of hypothetical patient scenarios revealed that the use of some BGMS could be associated with an increased risk of adverse events such as failure to detect hypoglycemia, driving with an unsafe BG level, delay of treatment intervention in diabetes during pregnancy, or the failure to prevent diabetic ketoacidosis.

CONCLUSIONS

This article can support both health care professionals and patients to understand the impact of BGMS accuracy in a relatable, clinical context. Furthermore, it is suggested that current accuracy requirements might be insufficient for the prevention of adverse clinical outcomes in certain circumstances.

Accuracy and user performance evaluation of a blood glucose monitoring system which wirelessly transmits results to compatible insulin pumps

Objective: To perform evaluations of the CONTOUR PLUS LINK 2.4 blood glucose monitoring system (BGMS) assessed according to ISO 15197:2013 criteria.Methods: Clinical trial registered at ClinicalTrials.gov (NCT01824355). In a laboratory study (Study 1), capillary fingertip blood samples from 100 subjects were evaluated in duplicate, using three test strip lots. In a clinical trial (Study 2), 113 adults with diabetes were enrolled, and BGMS results and Yellow Springs Instruments (YSI) analyzer reference measurements were compared for subject- and trial staff-obtained fingertip blood and subject-obtained palm blood. Subjects completed a questionnaire to evaluate BGMS ease of use.Results: In Study 1, 100% of combined results (all test strip lots) fulfilled ISO 15197:2013 section 6.3 criteria. In Study 2, 97.7% of subject-obtained fingertip results and 100% of trial staff-obtained fingertip results met ISO 15197:2013 section 8 criteria. Additionally, 93.8% of palm results were within ± 15 mg/dL of mean YSI measurements for glucose concentrations <100 mg/dL or ± 15% for glucose concentrations ≥100 mg/dL. Most subjects found the BGMS easy to use. There were three non-serious, non-device related adverse events.Conclusion: The BGMS exceeded minimum ISO 15197:2013-specified accuracy criteria in the laboratory and in the hands of lay users with diabetes.

Accuracy Beyond ISO: Introducing a New Method for Distinguishing Differences Between Blood Glucose Monitoring Systems Meeting ISO 15197:2013 Accuracy Requirements

BACKGROUND

Diabetes treatment is intended to maintain near-normal glycemic levels. Self-monitoring of blood glucose (SMBG) allows patients to track their BG levels compared with glycemic targets and is associated with improved health outcomes. Because of the importance of SMBG, it is essential that results are accurate to prevent errors in nutritional intake and drug dosing. This study presents a new methodology to evaluate the accuracy of BG monitoring systems (BGMSs).

METHODS

Sensitivity analyses were performed using real and simulated BGMS data to compute probabilities that, for any BG value, the BGMS result would be within prescribed error bounds and confidence limits compared with laboratory reference values. Multiple BG value ranges were used.

RESULTS

Probability curves were created using data from 3 simulated BGMSs and anonymized data from 3 real-world BGMSs. Accuracy probability curves from capillary fingertip blood samples (actual clinical data) showed that all 3 real-world BGMSs met EN ISO 15197:2015 accuracy criteria, since 99.63%, 99.63%, and 99.81% of results from the 3 BGMSs were within ±15 mg/dL or ±15% of reference for BG <100 mg/dL and ≥100 mg/dL, respectively. However, there was identifiable variability between BGMSs if BG was <70 mg/dL; one BGMS showed further reductions in accuracy if BG was <50 mg/dL.

CONCLUSIONS

Probability curves highlight the importance of BGMS accuracy to help achieve optimal glycemic control while avoiding hypoglycemia or hyperglycemia. This may be especially significant in very low BG ranges where small errors in BGMS measurements can have substantial impacts on patient-related outcomes, including hypoglycemia risk.

Intensive dietary intervention promoting the Mediterranean diet in people with high cardiometabolic risk: a non-randomized study

AIMS

Mediterranean diet (MD) is acknowledged to exert a number of beneficial health effects. We assessed the efficacy and the durability of a 3-month intensive dietary intervention aimed at implementing the MD on body weight and cardiometabolic risk factors in subjects at high risk.

METHODS

One hundred and sixteen subjects participated in the study (71 assigned to the intensive intervention and 45 to the conventional intervention). The intensive intervention consisted of 12 weekly group educational meetings and a free-of-charge supply of meals prepared according to the MD model. The conventional intervention consisted of an individual education session along with monthly reinforcements of nutritional messages by the general practitioner. All participants were followed up for 9 months.

RESULTS

The two groups had similar pre-intervention characteristics. After the intervention, mean body weight decreased significantly in both groups (p < 0.001). However, the intervention group lost more weight (6.8 ± 4.0 vs. 0.7 ± 1.3, p < 0.0001) and showed a greater reduction in plasma glucose, triglycerides, blood pressure and an increase in HDL cholesterol than the control group (p < 0.01-p < 0.002). In the subgroup of participants with type 2 diabetes, there was a significant reduction in HbA1c level following the intensive (p < 0.0001) but not the conventional intervention. At follow-up, weight loss still persisted in the intervention group (p < 0.0001), while it was lost in the control group. Both interventions significantly reduced blood pressure in the long term (p < 0.001). A significant reduction in daily total energy intake was observed in both groups with a greater reduction in saturated fat and a higher increase in fibre intake in the intervention than in the control group (p < 0.009 and p < 0.001, respectively).

CONCLUSIONS

A 3-month intensive dietary intervention inspired to the traditional MD produced greater and more durable weight loss and improvement in cardiometabolic risk profile than the conventional intervention.

Bolus Insulin Dose Error Distributions Based on Results From Two Clinical Trials Comparing Blood Glucose Monitoring Systems

BACKGROUND

In 2 previous clinical trials, fingertip capillary blood samples were evaluated using prespecified blood glucose monitoring systems (BGMSs) and a reference YSI glucose analyzer. In post hoc analyses, hypothetical insulin doses were calculated using these blood glucose measurements; dosing errors were compared for each trial.

METHOD

For each blood glucose measurement, premeal bolus insulin dosing was determined for a hypothetical person, assuming a 60-g carbohydrate meal and 100-mg/dL target blood glucose level (adjusting 1/25 insulin sensitivity and 1/15 insulin:carbohydrate ratio inputs to account for BGMS measurement error). Dosing error was the difference between doses calculated using the BGMS and YSI results.

RESULTS

In Clinical Trial 1, 95% dose error ranges (in units of insulin) were: CONTOUR®NEXT EZ BGMS (EZ), -0.9 to 0.5; Accu-Chek® Aviva BGMS (ACA), -0.5 to 1.8; FreeStyle Freedom Lite® BGMS (FFL), -3.2 to -0.3; OneTouch® Ultra®2 BGMS (OTU2), -4.1 to 0.3; and Truetrack® BGMS (TT), -3.9 to 2.2. In Clinical Trial 2, these ranges were: CONTOUR®NEXT BGMS (CN), -0.7 to 1.7; Accu-Chek® Aviva Nano BGMS (ACAN), -1.3 to 1.8; FreeStyle Lite® BGMS (FSL), -5.1 to 0.2; OTU2, -1.9 to 1.2; OneTouch® Verio® Pro BGMS (OTVP), -1.0 to 1.9; and TT, -5.1 to 1.7. Within each trial, EZ and CN had statistically significantly smaller insulin dose error ranges than other BGMSs ( P <0.0001).

CONCLUSIONS

The ranges of insulin dose errors were statistically significantly smaller with EZ and CN than with all other BGMSs in this post hoc analysis. Differences in BGMS accuracy could result in clinically important differences in insulin dosing.

Using Radar Plots to Demonstrate the Accuracy and Precision of 6 Blood Glucose Monitoring Systems

BACKGROUND

Previously, fingertip capillary blood glucose measurements from the CONTOUR^®NEXT (CN) blood glucose monitoring system (BGMS) and 5 other BGMSs were evaluated in comparison with measurements from a reference YSI glucose analyzer. Here, we use Radar Plots to graphically represent the accuracy and precision results from the previous study, including whether they met ISO 15197:2013 accuracy criteria.

METHOD

A Radar Plot, a new method for capturing a distinct, single visualization of BGMS analytical performance, is a collection of concentric circles, each representing a particular magnitude of error. The center of the plot represents zero error (BGMS result is equivalent to reference result); as points are more distant from the center, the error increases, expressed in units of mg/dL or percentage for YSI values <100 and ≥100 mg/dL, respectively. The position of the data point above or below the horizontal line bisecting the plot indicates whether the BGMS measurement error was positive (BGMS result > YSI result) or negative (BGMS result < YSI result). Points within the "15-15 Zone," representing ±15 mg/dL or ±15% error, satisfy ISO 15197:2013 accuracy criteria.

RESULTS

The percentage of results within the 15-15 Zone ranged from 83.6% to 99.8% for the 6 BGMSs (99.6% for CN).

CONCLUSIONS

Radar Plots provide a different method for visually comparing the analytical performance of multiple BGMSs. The tight clustering of data points at the center of the CN Radar Plot illustrates the analytical performance of CN compared with 5 other BGMSs.

Accuracy and User Performance Evaluation of a New, Wireless-enabled Blood Glucose Monitoring System That Links to a Smart Mobile Device

BACKGROUND

The new Contour^®Plus ONE blood glucose monitoring system (BGMS) features an easy-to-use, wireless-enabled blood glucose meter that links to a smart mobile device via Bluetooth^® connectivity and can sync with the Contour^™ Diabetes app on a smartphone or tablet.

METHODS

The accuracy of the new BGMS was assessed in 2 studies according to ISO 15197:2013 criteria. In Study 1 (laboratory study), fingertip capillary blood samples from 100 subjects were tested in duplicate using 3 test strip lots. In Study 2 (clinical study), 134 subjects with type 1 or type 2 diabetes enrolled at 2 clinical sites. BGMS results and YSI analyzer (YSI) reference results were compared for fingertip blood obtained by untrained subjects' self-testing and for study staff-obtained fingertip, subject palm, and venous results.

RESULTS

In Study 1, 99.0% (594/600) of combined results for all 3 test strip lots fulfilled ISO 15197:2013 Section 6.3 accuracy criteria. In Study 2, 99.2% (133/134) of subject-obtained capillary fingertip results, 99.2% (133/134) of study staff-obtained fingertip results, 99.2% (125/126) of subject-obtained palm results, and 100% (132/132) of study staff-obtained venous results met ISO 15197:2013 Section 8 accuracy criteria. Moreover, 95.5% (128/134) of subject-obtained fingertip self-test results were within ±10 mg/dl (±0.6 mmol/L) or ±10% of the YSI reference result. Questionnaire results showed that most subjects found the BGMS easy to use.

CONCLUSIONS

The BGMS exceeded ISO 15197:2013 accuracy criteria both in the laboratory and in a clinical setting when used by untrained subjects with diabetes.

A New, Wireless-enabled Blood Glucose Monitoring System That Links to a Smart Mobile Device: Accuracy and User Performance Evaluation

BACKGROUND

These studies investigated the accuracy of the new Contour^®Next ONE blood glucose monitoring system (BGMS) that is designed to sync with the Contour™ Diabetes app on a smartphone or tablet.

METHODS

A laboratory study tested fingertip capillary blood samples from 100 subjects in duplicate using 3 test strip lots, based on ISO 15197:2013 Section 6.3 analytical accuracy standards. A clinical study assessed accuracy per ISO 15197:2013 Section 8 criteria. Subjects with (n = 333) or without (n = 43) diabetes and who had not used the BGMS previously were enrolled. Each subject performed a self-test using the BGMS, which was repeated by a site staff member. Alternate site tests and venipunctures were also performed for analysis. A questionnaire was provided to assess user feedback on ease of use.

RESULTS

In the laboratory study, 100% (600/600) of combined results for all 3 test strip lots met ISO 15197:2013 Section 6.3 accuracy criteria. In the clinical study, among subjects with diabetes, 99.4% (327/329) of subject self-test results, 99.7% (331/332) of results obtained by study staff, 97.2% (309/318) of subject palm results, and 100% (330/330) of venous results met ISO 15197:2013 Section 8 accuracy criteria. Moreover, 97.6% (321/329) of subject self-test results were within ±10 mg/dl (±0.6 mmol/L) or ±10% of the YSI reference result. Questionnaire results indicated that most subjects considered the system easy to use.

CONCLUSIONS

The BGMS exceeded ISO 15197:2013 accuracy criteria in the laboratory and in a clinical setting.

The Quantitative Relationship Between ISO 15197 Accuracy Criteria and Mean Absolute Relative Difference (MARD) in the Evaluation of Analytical Performance of Self-Monitoring of Blood Glucose (SMBG) Systems

The relationship between International Organization for Standardization (ISO) accuracy criteria and mean absolute relative difference (MARD), 2 methods for assessing the accuracy of blood glucose meters, is complex. While lower MARD values are generally better than higher MARD values, it is not possible to define a particular MARD value that ensures a blood glucose meter will satisfy the ISO accuracy criteria. The MARD value that ensures passing the ISO accuracy test can be described only as a probabilistic range. In this work, a Bayesian model is presented to represent the relationship between ISO accuracy criteria and MARD. Under the assumptions made in this work, there is nearly a 100% chance of satisfying ISO 15197:2013 accuracy requirements if the MARD value is between 3.25% and 5.25%.

Fundamental Importance of Reference Glucose Analyzer Accuracy for Evaluating the Performance of Blood Glucose Monitoring Systems (BGMSs)

BACKGROUND

As blood glucose monitoring system (BGMS) accuracy is based on comparison of BGMS and laboratory reference glucose analyzer results, reference instrument accuracy is important to discriminate small differences between BGMS and reference glucose analyzer results. Here, we demonstrate the important role of reference glucose analyzer accuracy in BGMS accuracy evaluations.

METHODS

Two clinical studies assessed the performance of a new BGMS, using different reference instrument procedures. BGMS and YSI analyzer results were compared for fingertip blood that was obtained by untrained subjects' self-testing and study staff testing, respectively. YSI analyzer accuracy was monitored using traceable serum controls.

RESULTS

In study 1 (N = 136), 94.1% of BGMS results were within International Organization for Standardization (ISO) 15197:2013 accuracy criteria; YSI analyzer serum control results showed a negative bias (-0.64% to -2.48%) at the first site and a positive bias (3.36% to 6.91%) at the other site. In study 2 (N = 329), 97.8% of BGMS results were within accuracy criteria; serum controls showed minimal bias (<0.92%) at both sites.

CONCLUSIONS

These findings suggest that the ability to demonstrate that a BGMS meets accuracy guidelines is influenced by reference instrument accuracy.

Performance of a Blood Glucose Monitoring System in a Point-of-Care Setting

This study assesses and demonstrates that CONTOUR® XT-BGMS (CXT-BGMS) complies with the requirements of the German (RiliBÄK) and Swiss (QUALAB) quality control guidelines for point-of-care testing (POCT) and fulfills the ISO15197:2013 accuracy limits criteria under the routine conditions of a hospital point-of care setting. This single-center study was conducted in Switzerland using 105 venous blood samples from hospitalized patients. Each sample was tested in comparison to the hexokinase reference method. Compliance with POCT guidelines was assessed by daily BGMS measurements using control solutions. Accuracy of CXT-BGMS according to ISO limits was 98.41%. All control measurements were within the limits defined by RiliBÄK (within ± 11% of target values and root mean square error [RMSE] within RMSE limits), and QUALAB (within ± 10% of target values).

Performance Evaluation of Three Blood Glucose Monitoring Systems Using ISO 15197: 2013 Accuracy Criteria, Consensus and Surveillance Error Grid Analyses, and Insulin Dosing Error Modeling in a Hospital Setting

BACKGROUND

Blood glucose monitoring is an essential component of diabetes management. Inaccurate blood glucose measurements can severely impact patients' health. This study evaluated the performance of 3 blood glucose monitoring systems (BGMS), Contour® Next USB, FreeStyle InsuLinx®, and OneTouch® Verio™ IQ, under routine hospital conditions.

METHODS

Venous blood samples (N = 236) obtained for routine laboratory procedures were collected at a Spanish hospital, and blood glucose (BG) concentrations were measured with each BGMS and with the available reference (hexokinase) method. Accuracy of the 3 BGMS was compared according to ISO 15197:2013 accuracy limit criteria, by mean absolute relative difference (MARD), consensus error grid (CEG) and surveillance error grid (SEG) analyses, and an insulin dosing error model.

RESULTS

All BGMS met the accuracy limit criteria defined by ISO 15197:2013. While all measurements of the 3 BGMS were within low-risk zones in both error grid analyses, the Contour Next USB showed significantly smaller MARDs between reference values compared to the other 2 BGMS. Insulin dosing errors were lowest for the Contour Next USB than compared to the other systems.

CONCLUSIONS

All BGMS fulfilled ISO 15197:2013 accuracy limit criteria and CEG criterion. However, taking together all analyses, differences in performance of potential clinical relevance may be observed. Results showed that Contour Next USB had lowest MARD values across the tested glucose range, as compared with the 2 other BGMS. CEG and SEG analyses as well as calculation of the hypothetical bolus insulin dosing error suggest a high accuracy of the Contour Next USB.

Accuracy Evaluation of CONTOUR(®)PLUS Compared With Four Blood Glucose Monitoring Systems

INTRODUCTION

The aim of this study was to compare the accuracy of 5 blood glucose monitoring systems (BGMSs; CONTOUR(®)PLUS [CP], Accu-Chek(®) Active [ACA], Accu-Chek(®) Performa [ACP], FreeStyle Freedom™ [FF], OneTouch(®) SelectSimple™ [OTSS]).

METHODS

Study staff tested fingerstick samples from 106 subjects aged ≥18 years using the 5 BGMSs. Some samples were modified to achieve blood glucose concentrations throughout the measuring range. The primary endpoint was comparison of the mean absolute relative difference (MARD) from the reference value (Yellow Springs Instruments [YSI]) across the overall tested glucose range. Other endpoints were MARD in the low (≤80 mg/dL [≤4.4 mmol/L]), middle (81-180 mg/dL [4.5-10.0 mmol/L]), and high (>180 mg/dL [>10.0 mmol/L]) glucose ranges, and MARD for unmodified samples in the overall glucose range.

RESULTS

CONTOUR(®)PLUS had a statistically significantly lower MARD than all BGMSs across the overall tested range (27-460 mg/dL [1.5-25.5 mmol/L]) and in the high glucose range. In the low glucose range, CP had a lower MARD than all BGMSs, which was statistically significant except for ACP. For unmodified samples across the overall tested range, CP had a lower MARD than all BGMSs and was statistically significantly lower except for ACA.

CONCLUSIONS

CONTOUR(®)PLUS had the lowest mean difference from the reference values (by MARD) when compared with other BGMSs across multiple glucose ranges with modified and unmodified samples.

FUNDING

Bayer HealthCare LLC, Diabetes Care.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier NCT01714232.

A Multicenter Performance Evaluation of a Blood Glucose Monitoring System in 21 Leading Hospitals in Spain

BACKGROUND

Self-monitoring of blood glucose is crucial for the effective self-management of diabetes. The present study evaluated the accuracy of the Contour® XT blood glucose monitoring system (BGMS) compared to the reference method in a large multicenter study under routine lab conditions at each hospital site.

METHODS

This study was conducted at 21 leading hospitals in Spain using leftover whole blood samples (n = 2100). Samples were tested with the BGMS using 1 commercial strip lot and the local laboratory hexokinase method. BGMS accuracy was assessed and results were compared to ISO 15197:2013 accuracy limit criteria and by using mean absolute relative difference analysis (MARD), consensus (Parkes) error grid (CEG), and surveillance error grid analyses (SEG).

RESULTS

Pooled analysis of 2100 measurements from all sites showed that 99.43% of the BGMS results were within the ranges accepted by the accuracy limit criteria. The overall MARD was 3.85%. MARD was 4.47% for glucose concentrations < 70 mg/dL and 3.81% for concentrations of 70-300 mg/dL. In CEG, most results (99.8%) were within zone A ("no effect on clinical action"); the remaining ones (0.2%) were in zone B ("little to no effect on clinical action"). The SEG analysis showed that most of the results (98.4%) were in the "no risk" zone, with the remaining results in the "slight, lower" risk zone.

CONCLUSIONS

This is the largest multicenter study of Contour XT BGMS to date, and shows that this BGMS meets the ISO 15197:2013 accuracy limit criteria under local routine conditions in 21 leading Spanish hospitals.

Accuracy and user performance evaluation of a blood glucose monitoring system

BACKGROUND

The accuracy of the Contour(®) Plus (Bayer HealthCare LLC, Diabetes Care, Whippany, NJ) blood glucose monitoring system (BGMS) was evaluated in two separate studies.

MATERIALS AND METHODS

In the laboratory study, fingerstick samples from 100 subjects were tested in duplicate using three test strip lots and assessed per International Organization for Standardization (ISO) 15197:2003, Section 7 (≥95% of results within ±15 mg/dL or ±20% of the reference result for samples with glucose concentrations <75 and ≥75 mg/dL, respectively) and ISO 15197:2013, Section 6.3 (≥95% of results within ±15 mg/dL or ±15% of the reference result for samples with glucose concentrations <100 and ≥100 mg/dL, respectively) accuracy criteria. In the clinical trial, 220 subjects with diabetes, naive to the BGMS, tested capillary glucose from fingertip and palm blood samples and completed an ease-of-use questionnaire. BGMS and YSI glucose analyzer results were compared.

RESULTS

In the laboratory study, 100% of results met ISO 15197:2003 and ISO 15197:2013 accuracy criteria. In the clinical trial, 100% and 99.1% of subject fingerstick results and 98.1% and 96.7% of subject palm results met ISO 15197:2003 and ISO 15197:2013 accuracy criteria, respectively. By Parkes Consensus Error Grid analysis, 100% of subject fingerstick results and 98.1% of subject palm results were within Zone A (remainder within Zone B). Questionnaire results showed most subjects found the BGMS easy to use.

CONCLUSIONS

The Contour Plus BGMS meets ISO 15197:2003 and ISO 15197:2013 accuracy criteria in the laboratory and when used by untrained individuals.

Analytic characteristics of three Bayer contour blood glucose monitoring systems in neonates

Hypoglycemia in infants is common, is difficult to recognize, and may lead to permanent neurologic impairment. Low glucose concentrations and high hematocrits in newborns pose significant analytic challenges for whole blood glucose meters. Three Bayer glucose monitoring systems were evaluated using 211 blood samples from 162 neonates (age range 5 hours to 29 days, median age 3 days). Hematocrit and whole blood glucose were determined in heparinized whole blood, and plasma glucose was determined using the Roche Cobas 6000. Accuracy was evaluated against plasma concentrations using ISO 15197:2013 and CLSI POCT 12-A3 criteria. Glucose imprecision on the Cobas system was 1.8-2.6% (CV) from 26-610 mg/dL. Imprecision across all meter systems was 2.8% (CV) at 130 mg/dL. Glucose concentrations, hematocrit, and total bilirubin ranged from 20-150 mg/dL, 18 -75%, and 0.5-19.6 mg/dL, respectively. Linear regression analysis of whole blood versus plasma for the 3 combined systems yielded an average slope of 1.06 and correlation coefficient greater than 0.980. Bias between the Contour and Cobas was not significantly correlated with hematocrit. Greater than 99% of meter results were within 15 mg/dL and 20% of plasma results at glucose concentrations ≤ 75 and > 75 mg/dL, respectively. Of meter results, 97% were within 12.5 mg/dL of plasma results at concentrations ≤ 100 mg/dL, while 96% of meter results were within 12.5% of plasma at concentrations > 100 mg/dL. The Bayer CONTOUR Blood Glucose Monitoring Systems exceed ISO 15197:2013 and CLSI criteria in neonatal blood samples.

Accuracy evaluation of contour next compared with five blood glucose monitoring systems across a wide range of blood glucose concentrations occurring in a clinical research setting

BACKGROUND

This study evaluated the accuracy of Contour(®) Next (CN; Bayer HealthCare LLC, Diabetes Care, Whippany, NJ) compared with five blood glucose monitoring systems (BGMSs) across a wide range of clinically occurring blood glucose levels.

SUBJECTS AND METHODS

Subjects (n=146) were ≥ 18 years and had type 1 or type 2 diabetes. Subjects' glucose levels were safely lowered or raised to provide a wide range of glucose values. Capillary blood samples were tested on six BGMSs and a YSI glucose analyzer (YSI Life Sciences, Inc., Yellow Springs, OH) as the reference. Extreme glucose values were achieved by glucose modification of the blood sample. System accuracy was assessed by mean absolute difference (MAD) and mean absolute relative difference (MARD) across several glucose ranges, with <70 mg/dL evaluated by MAD as the primary end point.

RESULTS

In the low glucose range (<70 mg/dL), MAD values were as follows: Accu-Chek(®) Aviva Nano (Roche Diagnostics, Indianapolis, IN), 3.34 mg/dL; CN, 2.03 mg/dL; FreeStyle Lite(®) (FSL; Abbott Diabetes Care, Inc., Alameda, CA), 2.77 mg/dL; OneTouch(®) Ultra(®) 2 (LifeScan, Inc., Milpitas, CA), 10.20 mg/dL; OneTouch(®) Verio(®) Pro (LifeScan, Inc.), 4.53 mg/dL; and Truetrack(®) (Nipro Diagnostics, Inc., Fort Lauderdale, FL), 11.08 mg/dL. The lowest MAD in the low glucose range, from CN, was statistically significantly lower than those of the other BGMSs with the exception of the FSL. CN also had a statistically significantly lower MARD than all other BGMSs in the low glucose range. In the overall glucose range (21-496 mg/dL), CN yielded the lowest MAD and MARD values, which were statistically significantly lower in comparison with the other BGMSs.

CONCLUSIONS

When compared with other BGMSs, CN demonstrated the lowest mean deviation from the reference value (by MAD and MARD) across multiple glucose ranges.

Comparative Accuracy of 3 Blood Glucose Monitoring Systems that Communicate with an Insulin Pump

OBJECTIVE

This study compared the accuracy of the Contour® Next Link blood glucose monitoring system (BGMS) with 2 other BGMSs (OneTouch® UltraLink® and Nova Max Link™), all 3 of which can communicate wirelessly with an insulin pump.

METHODS

Study staff tested fingerstick samples from 112 subjects aged ≥18 years with each BGMS. All BGMS results were compared to YSI 2300 STAT Plus™ Glucose Analyzer results from the same sample source. To safely obtain a wide range of glucose values, 3 blood samples were obtained from each subject (1 sample was tested fresh from the fingertip [unmodified], and the other 2 samples were modified to raise or lower the glucose concentration). The primary endpoint evaluated was difference in accuracy among the BGMSs across the entire tested glucose range (34 to 561 mg/dL). Additional comparisons were made of accuracy in the low (≤80 mg/dL) and high (>180 mg/dL) glucose ranges. BGMS accuracy was assessed by mean absolute relative difference (MARD).

RESULTS

The Contour® Next Link BGMS had a statistically significantly lower MARD from the reference value than the other BGMSs across the entire tested glucose range, calculated using all samples as well as only unmodified (i.e., natural) samples. In the low and high glucose ranges, the Contour® Next Link also had a statistically significantly lower MARD from the reference value than the other BGMSs.

CONCLUSION

As assessed by MARD, the Contour® Next Link BGMS was significantly more accurate than the other BGMSs evaluated, all of which can communicate wirelessly with an insulin pump.

Testing versus guessing blood glucose values: impact on self-care behaviors in type 2 diabetes

OBJECTIVE

To assess differences between estimated blood glucose values and those measured on a blood glucose meter and the impact on self-care behavior in type 2 diabetes.

RESEARCH DESIGN AND METHODS

Subjects ≥18 years with type 2 diabetes (N = 297) attending a Taking Control of Your Diabetes conference were asked questions about diabetes management and to estimate their current blood glucose. Study staff tested subjects' blood glucose on a meter. After seeing the result, subjects were again asked questions on diabetes management.

CLINICAL TRIAL REGISTRATION

NCT01453413.

MAIN OUTCOME MEASURE

The percentage of subject blood glucose estimations that were outside ISO 15197:2003 accuracy criteria (>±15 mg/dL or >±20% of meter glucose values).

RESULTS

Nearly half (46%) of subjects estimated blood glucose values outside ISO 15197:2003 accuracy criteria. Time since last blood glucose test, time since last meal, testing frequency, and A1C did not have an effect on differences between estimated blood glucose values and meter results. In the questionnaire before blood glucose testing, most subjects strongly agreed, agreed, or neither agreed nor disagreed that 'I make decisions about my diabetes, such as my food intake or my insulin dose even when I do not test my blood sugar' (71%) and 'My body tells me without testing if my blood sugar is low or high' (77%). After blood glucose testing, 99% of subjects strongly agreed, agreed, or neither agreed nor disagreed that 'Knowing my blood sugar by checking could help me make different diabetes decisions'.

CONCLUSIONS

Self-monitoring of blood glucose is an important component of diabetes self-management. Testing rather than guessing blood glucose values is important to obtain accurate results and inform people with type 2 diabetes to make effective, appropriate diabetes management decisions. A potential limitation of this study is that the subject population may not be representative of the general population of people with diabetes; however, the conference setting may attract a more motivated population, which could underestimate the magnitude of the results.

A new test strip technology platform for self-monitoring of blood glucose

In the management of diabetes, accuracy of devices used for self-monitoring of blood glucose (SMBG) is critical because SMBG results can affect patient diabetes-related health outcomes. A new blood glucose monitoring system (BGMS) platform has been developed that is based on the new CONTOUR® NEXT (CN) test strip. This BGMS platform uses a proprietary electron mediator and algorithm to minimize errors at different steps in the testing process, thus minimizing outliers and significantly improving accuracy from prior-generation blood glucose meter systems. As demonstrated by questionnaire results from clinical studies with the new BGMS platform, accuracy and ease of use are important considerations for people with diabetes and their health care professionals when selecting an SMBG device. This article provides an overview of laboratory studies and clinical trials in the hands of lay users involving the performance of the portfolio of blood glucose meters that uses the new test strip. Each BGMS in the platform, which includes the CONTOUR XT (CONTOUR NEXT EZ in the United States), CONTOUR NEXT LINK, CONTOUR NEXT USB, and CN systems, demonstrated advanced accuracy both in the laboratory and in the hands of subjects (people with diabetes) and trained health care professionals. All systems met and exceeded International Organization for Standardization accuracy criteria (both ISO 15197:2003 and ISO 15197:2013). Each system in the new BGMS platform delivers advanced accuracy, which is essential to people who utilize SMBG for improved management.

Technical aspects of the Parkes error grid

BACKGROUND

The Parkes error grid, which was developed in 1994, presented performance zones for blood glucose (BG) monitors with borders that were not mathematically specified at the time the grid was published.

METHODS

In this article, we (1) review the history of the Parkes error grid, (2) present the never-before-published exact coordinates and specifications of the grid so that others may produce an exact replica of the original grid, and (3) discuss our suggestions how this metric should be applied.

RESULTS

The new ISO15197:2013 guideline for system accuracy assessment of BG meters for patient self-measurement incorporates use of this metric for defining acceptable accuracy of BG monitors. It is expected that, for regulatory purposes, this document will stipulate that the error grid version for type 1 diabetes should be applied with the caveat that only the A zone represents acceptable accuracy.

CONCLUSIONS

It remains to be seen by how much the new error grid, which is currently being developed by the Food and Drug Administration/Diabetes Technology Society/American Diabetes Association/The Endocrine Society/Association for Advancement of Medical Instrumentation, will deviate from the Parkers error grid.

Accuracy evaluation of five blood glucose monitoring systems: the North American comparator trial

BACKGROUND

This study evaluated differences in accuracy between the CONTOUR® NEXT EZ (EZ) blood glucose monitoring system (BGMS) and four other BGMSs [ACCU-CHEK® Aviva (ACAP), FreeStyle Freedom Lite® (FFL), ONE TOUCH® Ultra®2 (OTU2), and TRUEtrack® (TT)].

METHODS

Up to three capillary blood samples (N = 393) were collected from 146 subjects with and without diabetes. One sample per subject was tested with fresh (natural) blood; the other samples were glycolyzed to lower blood glucose to <70 mg/dl. Meter results were compared with results from plasma from the same sample tested on a Yellow Springs Instruments (YSI) 2300 STAT PlusTM glucose analyzer. Blood glucose monitoring system accuracy was compared using mean absolute relative difference (MARD; from laboratory reference method results) and other analyses. Separate analyses on fresh (natural) samples only were conducted to determine potential effects of glycolysis on MARD values of systems utilizing glucose-oxidase-based test strip chemistry.

RESULTS

Across the tested glucose range, the EZ had the lowest MARD of 4.7%; the ACAP, FFL, OTU2, and TT had MARD values of 6.3%, 18.3%, 23.4%, and 26.2%, respectively. For samples with glucose concentrations <70 mg/dl, the EZ had the lowest MARD (0.65%), compared with the ACAP (2.5%), FFL (18.3%), OTU2 (22.4%), and TT (33.2%) systems.

CONCLUSIONS

The EZ had the lowest MARD across the tested glucose ranges when compared with four other BGMSs when all samples were analyzed as well as when natural samples only were analyzed.

Evaluation of a combined blood glucose monitoring and gaming system (Didget®) for motivation in children, adolescents, and young adults with type 1 diabetes

The purpose of this study was to assess the performance and acceptability of a blood glucose meter coupled with a gaming system for children, adolescents, and young adults with type 1 diabetes. During an in-clinic visit, duplicate blood samples were tested by subjects (N = 147; aged 5-24 yr) and health care providers (HCPs) to evaluate the accuracy and precision of the Didget® system. Subjects' meter results were compared against Yellow Springs Instruments (YSI) reference results and HCP results using least squares regression and error grid analyses. Precision was measured by average within-subject and within-HCP coefficient of variation (CV). During the home-use component of this study, subjects (n = 58) tested their blood glucose at least two to three times daily for 3-5 d to evaluate routine use of the system. Subjects' meter results showed significant correlations with both YSI (r(2) = 0.94; p < 0.001 for regression slope) and HCP results (r(2) = 0.96; p < 0.001). Average within-subject and within-HCP CVs were 5.9 and 7.2%, respectively. Overall satisfaction was assessed by subjects, their parents or guardians, and HCP surveys. Subject satisfaction with the Didget® system was good to excellent; most subjects found the system easy to use, motivating, and helpful for building good blood glucose monitoring habits. Most HCPs agreed that the system fulfilled a need in diabetes management. In conclusion, the Didget® system was precise and clinically accurate in the hands of children, adolescents, and young adults with type 1 diabetes.

Advanced meter features improve postprandial and paired self-monitoring of blood glucose in individuals with diabetes: results of the Actions with the CONTOUR Blood Glucose Meter and Behaviors in Frequent Testers (ACT) study

BACKGROUND

This study evaluated whether education and use of the advanced meter features of the CONTOUR(®) (Bayer HealthCare LLC, Diabetes Care, Tarrytown, NY) blood glucose monitoring system (BGMS) affect the frequency and pattern of blood glucose testing in insulin-using subjects with diabetes who routinely perform self-monitoring of blood glucose (SMBG).

SUBJECTS AND METHODS

Insulin-using subjects with type 1 or type 2 diabetes were enrolled in this 6-month, multicenter, prospective study and randomized to one of two groups. The basic meter features group (BMF group) received basic instruction in the use of the BGMS, whereas the advanced meter features group (AMF group) also received training in the use of advanced features, including the meal marker and audible reminder, and were instructed to use these features. Both groups received education on the importance of postprandial testing.

RESULTS

The AMF group (n=105) had significantly greater average weekly postprandial blood glucose testing than the BMF group (n=106) at each follow-up visit (P<0.001) and significantly increased the frequency of paired blood glucose testing (P<0.001) as well. In both groups, glycated hemoglobin decreased significantly as postprandial testing frequency increased (P<0.05). Subject reports indicated that use of advanced features made postmeal SMBG considerably easier to remember, helped them better understand how to make decisions on their own, and increased their confidence in meal choices.

CONCLUSIONS

Study findings showed that advanced features of the CONTOUR BGMS increased structured testing as measured by postprandial and paired SMBG and were perceived as useful by patients.

Performance of a new blood glucose monitoring system in the hands of intended users

BACKGROUND

This study assessed the performance of a blood glucose monitoring system (BGMS) in development that uses a new generation of blood glucose test strips with capillary and venous blood in the hands of its intended users, people with diabetes and healthcare professionals (HCPs).

SUBJECTS AND METHODS

In total, 93 subjects ≥ 18 years old (median age, 33 years) with type 1 (78%) or type 2 (22%) diabetes participated. Untrained subjects performed self-test fingersticks using a Microlet(®)2 lancing device (Bayer HealthCare LLC, Diabetes Care, Tarrytown, NY) followed by testing of their own capillary blood on the BGMS. HCPs performed fingersticks (using a Tenderlett(®) lancing device [International Technidyne Corp., Edison, NJ]) and venipunctures on subjects and tested both capillary and venous samples from subjects on the BGMS. All BGMS results were compared with Yellow Springs Instruments (YSI) (YSI Life Sciences, Inc., Yellow Springs, OH) laboratory results. Analytical accuracy was assessed according to International Organization for Standardization (ISO) 15197:2003 guidelines (i.e., within ± 15 mg/dL or ± 20% of the YSI results for samples with glucose concentrations < 75 mg/dL and ≥ 75 mg/dL, respectively) and more stringent criteria (i.e., within ± 15 mg/dL or ± 15% of the YSI results for samples with glucose concentrations < 100 mg/dL and ≥ 100 mg/dL, respectively).

RESULTS

Overall, 98.9% (180/182) of subject Microlet2 capillary fingerstick results, 99.5% (182/183) of HCP Tenderlett capillary fingerstick results, and 100% (186/186) of venous results met current ISO criteria and more stringent criteria. The average hematocrit was 44%, with values ranging from 32% to 52%.

CONCLUSIONS

Test results from both capillary fingerstick and venous samples with a new BGMS in development met current accuracy guidelines as well as proposed tighter criteria.

Performance evaluation and labeling comprehension of a new blood glucose monitoring system with integrated information management

BACKGROUND

This study evaluated performance and product labeling of CONTOUR® USB, a new blood glucose monitoring system (BGMS) with integrated diabetes management software and a universal serial bus (USB) port, in the hands of untrained lay users and health care professionals (HCPs).

METHOD

Subjects and HCPs tested subject's finger stick capillary blood in parallel using CONTOUR USB meters; deep finger stick blood was tested on a Yellow Springs Instruments (YSI) glucose analyzer for reference. Duplicate results by both subjects and HCPs were obtained to assess system precision. System accuracy was assessed according to International Organization for Standardization (ISO) 15197:2003 guidelines [within ±15 mg/dl of mean YSI results (samples <75 mg/dl) and ±20% (samples ≥75 mg/dl)]. Clinical accuracy was determined by Parkes error grid analysis. Subject labeling comprehension was assessed by HCP ratings of subject proficiency. Key system features and ease-of-use were evaluated by subject questionnaires.

RESULTS

All subjects who completed the study (N = 74) successfully performed blood glucose measurements, connected the meter to a laptop computer, and used key features of the system. The system was accurate; 98.6% (146/148) of subject results and 96.6% (143/148) of HCP results exceeded ISO 15197:2003 criteria. All subject and HCP results were clinically accurate (97.3%; zone A) or associated with benign errors (2.7%; zone B). The majority of subjects rated features of the BGMS as "very good" or "excellent."

CONCLUSIONS

CONTOUR USB exceeded ISO 15197:2003 system performance criteria in the hands of untrained lay users. Subjects understood the product labeling, found the system easy to use, and successfully performed blood glucose testing.

Performance of the DIDGET blood glucose monitoring system in children, teens, and young adults

BACKGROUND

This study evaluated the performance of the DIDGET® blood glucose monitoring system (BGMS) in the hands of its intended users: children, teens, and young adults with diabetes.

METHODS

Finger stick capillary blood samples were tested in duplicate by subjects (with parent/guardian assistance, if needed) and health care professionals using the DIDGET BGMS, and results were compared with those obtained using a Yellow Springs Instruments (YSI) glucose analyzer. Modified venous blood samples (i.e., glycolyzed or spiked with glucose) were used to analyze meter performance under extreme glucose concentrations. Accuracy was assessed using International Organization for Standardization (ISO) 15197:2003 guidelines (i.e., 95% of meter results within ±15 mg/dl or ±20% of reference values).

RESULTS

A total of 123 subjects aged 4 to 24 years with type 1 or type 2 diabetes were enrolled. The DIDGET meter achieved accuracy according to ISO 15197:2003 criteria: >97% of meter results were within ±15 mg/dl or ±20% of reference values. Regression analyses showed a high degree of correlation between meter and YSI results: coefficient of determination (R(2)) = 98.2% for all samples combined and 97.2% for capillary samples only. Clinical accuracy for combined samples was demonstrated by Parkes consensus error grid analyses; 100% of meter results were in zone A (98.5%) or zone B (1.5%). There was no difference in performance or accuracy across age subsets. Hematocrit values did not affect meter blood glucose results.

CONCLUSION

The DIDGET BGMS provided accurate test results across all age ranges in children, teens, and young adults with diabetes.

Evaluation of a novel continuous glucose measurement device in patients with diabetes mellitus across the glycemic range

BACKGROUND

This glucose clamp study assessed the performance of an electrochemical continuous glucose monitoring (CGM) system for monitoring levels of interstitial glucose. This novel system does not require use of a trocar or needle for sensor insertion.

METHOD

Continuous glucose monitoring sensors were inserted subcutaneously into the abdominal tissue of 14 adults with type 1 or type 2 diabetes. Subjects underwent an automated glucose clamp procedure with four consecutive post-steady-state glucose plateau periods (40 min each): (a) hypoglycemic (50 mg/dl), (b) hyperglycemic (250 mg/dl), (c) second hypoglycemic (50 mg/dl), and (d) euglycemic (90 mg/dl). Plasma glucose results obtained with YSI glucose analyzers were used for sensor calibration. Accuracy was assessed retrospectively for plateau periods and transition states, when glucose levels were changing rapidly (approximately 2 mg/dl/min).

RESULTS

Mean absolute percent difference (APD) was lowest during hypoglycemic plateaus (11.68%, 14.15%) and the euglycemic-to-hypoglycemic transition (14.21%). Mean APD during the hyperglycemic plateau was 17.11%; mean APDs were 18.12% and 19.25% during the hypoglycemic-to-hyperglycemic and hyperglycemic-to-hypoglycemic transitions, respectively. Parkes (consensus) error grid analysis (EGA) and rate EGA of the plateaus and transition periods, respectively, yielded 86.8% and 68.6% accurate results (zone A) and 12.1% and 20.0% benign errors (zone B). Continuous EGA yielded 88.5%, 75.4%, and 79.3% accurate results and 8.3%, 14.3%, and 2.4% benign errors for the euglycemic, hyperglycemic, and hypoglycemic transition periods, respectively. Adverse events were mild and unlikely to be device related.

CONCLUSION

This novel CGM system was safe and accurate across the clinically relevant glucose range.

Performance of the CONTOUR® TS Blood Glucose Monitoring System

BACKGROUND

Self-monitoring of blood glucose (SMBG) remains an important component of diabetes management, engendering a need for affordable blood glucose (BG) meters that are accurate, precise, and convenient. The CONTOUR® TS is a BG meter that endeavors to meet this need. It uses glucose dehydrogenase/flavin dinucleotide chemistry, automatic test strip calibration, and autocompensation for hematocrit along with the ease of use that has come to be expected of a modern meter. The objective of this clinical trial was to determine whether the CONTOUR TS system met these criteria.

METHODS

The system was evaluated at a single clinical site with 106 subjects with type 1 or type 2 diabetes. Blood glucose values ranged from 60 to 333 mg/dl over all subjects. Both lay users and health care professionals (HCPs) tested the meters, with test strips from three different lots. Results were compared to a reference analyzer of verified precision and accuracy. Forty-nine of the subjects also participated in a home study of the meter. Lay users learned to use the system without assistance and were surveyed on its use at the end of the study.

RESULTS

When used with capillary blood, both subjects and HCPs obtained results that exceeded the International Organization for Standardization 15197:2003 criteria, (i.e., ≥95% of values fell within 20% or 15 mg/dl of the laboratory value for BG levels greater than or less than 75 mg/dl, respectively). Specifically, lay users achieved 97.9% and HCPs 98.6%. When used with venous blood, 99.8% of measurements were within the criteria. All measurements for both capillary and venous blood fell into zones A or B of the Parkes error grid, deemed clinically accurate. Hematocrit was found to have no influence on BG measurements. A large majority of the subjects found the system easy to learn and to use.

CONCLUSIONS

The CONTOUR TS BG meter system gave accurate and reproducible results with both capillary and venous blood; subjects learned to use the meter system by following the user guide and quick reference guide.

Evaluation of an over-the-counter glycated hemoglobin (A1C) test kit

BACKGROUND

Glycated hemoglobin (A1C) monitoring is an integral component of diabetes management. This study was conducted to evaluate the performance of the A1CNow® SELFCHECK device when used by lay users and health care professionals (HCPs) to measure A1C.

METHODS

Subjects performed two A1CNow SELFCHECK finger-stick self-tests followed by a finger-stick test of the subject's blood by a HCP. The primary endpoint assessed accuracy of the subject and HCP A1CNow SELFCHECK readings. Secondary endpoints included precision, comprehension of instructional material (written material±DVD), and product satisfaction. For accuracy comparison, a venous blood sample was drawn from each subject and tested by laboratory (TOSOH) analysis. Subject comprehension of product instructional material was evaluated via first-time failure (FTF) rate as recorded by the HCP, and subject satisfaction was assessed through written survey.

RESULTS

A total of 110 subjects with (n=93) and without (n=17) diabetes participated. Of 177 subject A1C values, 165 (93.2%) were within the acceptable range of ±13.5% of the laboratory reference value and considered accurate. Regression analysis showed good correlation of subject values to laboratory and HCP results (R2=0.93 for both). The average within-subject coefficient of variation was 4.57% (n=74). The FTF rates with and without instructional DVD were 11.3% (n=56) and 39.6% (n=54), respectively. Subjects with diabetes/prediabetes overwhelmingly indicated that they were "very" to "extremely" likely (93.5%) to discuss their home A1C results with their HCP.

CONCLUSIONS

Lay users found the A1CNow SELFCHECK easy to use, and both lay users and HCPs were able to measure A1C accurately.

[How to identify adverse events in emergency services? A guide agreed for the screening]

OBJECTIVE

Since a third of adverse events (AE) occur outside hospital, the Emergency Services are a suitable place to look at their incidence. We considered designing a screening guide, adapted to the conditions of the emergency services, to identify AE.

MATERIAL AND METHODS

A qualitative technique was applied (nominal group) in which 14 professionals participated. They analysed which factors of intrinsic risk, extrinsic risk, and alert conditions, were suitable for a screening guide of AE in emergency services. The session was chaired by a specialist in these types of techniques.

RESULTS

Consensus was high in that the most frequent AE in emergencies were those related to medicines, diagnostic tests and with the correct identification of the reason for emergency. With respect to screening guide, the group proposed adding alcohol abuse, patient social problems, cognitive deterioration, basal autonomy and disability. In relation to extrinsic risk factors, they pointed to the need of including defibrillation, spinal tap or drainage implantation. With respect to the alert conditions form, the professionals agreed in that all the criteria seemed correct and suitable, except for that related to damage relation childbirth or amniocentesis.

CONCLUSIONS

By using this technique we have managed to validate materials already recognized, and widely used in our country. The screening guide was considered useful, with slight modifications in some risk factors and alert conditions. The professionals agreed that the MRF2 modular questionnaire is appropriate for the characterisation of AE in emergencies.

Predicted blood glucose from insulin administration based on values from miscoded glucose meters

OBJECTIVES

The proper use of many types of self-monitored blood glucose (SMBG) meters requires calibration to match strip code. Studies have demonstrated the occurrence and impact on insulin dose of coding errors with SMBG meters. This paper reflects additional analyses performed with data from Raine et al. (JDST, 2:205-210, 2007). It attempts to relate potential insulin dose errors to possible adverse blood glucose outcomes when glucose meters are miscoded.

METHODS

Five sets of glucose meters were used. Two sets of meters were autocoded and therefore could not be miscoded, and three sets required manual coding. Two of each set of manually coded meters were deliberately miscoded, and one from each set was properly coded. Subjects (n = 116) had finger stick blood glucose obtained at fasting, as well as at 1 and 2 hours after a fixed meal (Boost((R)); Novartis Medical Nutrition U.S., Basel, Switzerland). Deviations of meter blood glucose results from the reference method (YSI) were used to predict insulin dose errors and resultant blood glucose outcomes based on these deviations.

RESULTS

Using insulin sensitivity data, it was determined that, given an actual blood glucose of 150-400 mg/dl, an error greater than +40 mg/dl would be required to calculate an insulin dose sufficient to produce a blood glucose of less than 70 mg/dl. Conversely, an error less than or equal to -70 mg/dl would be required to derive an insulin dose insufficient to correct an elevated blood glucose to less than 180 mg/dl. For miscoded meters, the estimated probability to produce a blood glucose reduction to less than or equal to 70 mg/dl was 10.40%. The corresponding probabilities for autocoded and correctly coded manual meters were 2.52% (p < 0.0001) and 1.46% (p < 0.0001), respectively. Furthermore, the errors from miscoded meters were large enough to produce a calculated blood glucose outcome less than or equal to 50 mg/dl in 42 of 833 instances. Autocoded meters produced zero (0) outcomes less than or equal to 50 mg/dl out of 279 instances, and correctly coded manual meters produced 1 of 416.

CONCLUSIONS

Improperly coded blood glucose meters present the potential for insulin dose errors and resultant clinically significant hypoglycemia or hyperglycemia. Patients should be instructed and periodically reinstructed in the proper use of blood glucose meters, particularly for meters that require coding.

Biochemical and molecular diagnosis of lipoamide dehydrogenase deficiency in a North American Ashkenazi Jewish family

A late-onset presentation of lipoamide dehydrogenase (E3) deficiency is described in a North American Ashkenazi Jewish (AJ) family. Diagnosis was made by urine organic acid and molecular analyses.

Intra-articular osteoid osteoma: diagnostic imaging in three cases

PURPOSE

To report our experience pertaining to three cases of intra-articular osteoid osteoma assessed by means of integrated imaging and review of literature.

MATERIALS AND METHODS

Medical records, radiologic and nuclear medicine findings pertaining to three cases of intra-articular osteoid osteoma were retrospectively evaluated and compared with those of surgery. All the patients (2 males, one female; age range 8-38 ys) affected by intra-articular osteoid osteoma respectively of the elbow, tibio-talar joint and hip were evaluated by means of radiographic examination and Magnetic Resonance Imaging (MRI). SE T1-w and T2-w, GRE T2*-w, GRE 3D T1-w and STIR pulse sequences were used and axial, coronal and sagittal images were acquired. Two patients underwent CT scan. One patient underwent skeletal scintigraphy. All the patients underwent surgery.

RESULTS

In 2 out of 3 cases plain radiography allowed the radiologist to suspect the presence of the lesion. In the remaining one, plain radiography failed to detect both the nidus and the perilesional osteosclerosis; nevertheless, a small osteochondral erosion of the humeral condyle suggested the presence of joint inflammation, thus leading to further investigation. CT scan well depicted the presence of the nidus and, in one case, the presence of joint effusion. MRI was always able to detect the nidus, which presented as lesion of low to intermediate signal in T1-w images, low signal in the T2-w images in one patient and high signal in the remaining two; in these latter STIR images showed high intensity nidus and edema of neighbouring cancellous bone. Furthermore, in all patients MRI clearly depicted joint effusion. Skeletal scintigraphy demonstrated both the lesion and the inflammatory involvement of neighbouring soft tissue. In all patients histologic specimen confirmed the diagnosis of osteoid osteoma with joint inflammation and synovitis.

CONCLUSIONS

According to our results and literature data the pre-surgical diagnosis of osteoid osteoma is very difficult to achieve. Indeed, only the combination of clinical information and radiologic and nuclear medicine findings enables the radiologist to make the right diagnosis.

[Adult intestinal intussusception: comparison between CT features and surgical findings]

PURPOSE

To report our experience in the use of CT in the evaluation of adult intestinal intussusception. A correlation between radiologic findings and surgery was attempted in order to verify our diagnostic hypothesis.

MATERIAL AND METHODS

Intestinal intussusception was diagnosed by CT between September 1993 and December 2000 in 10 patients (6 men and 4 women, age range 18-82 years). For 9/10 patients the diagnosis was confirmed by surgery; in one patient the condition resolved spontaneously as confirmed by a follow-up CT performed 24 hours after the first. Six patients were studied by a third generation CT and four by a helical CT unit. Five patients were administered iodinated oral contrast medium and in seven i.v. iodinated contrast medium. Diagnosis was hypothesized at CT on the basis of the following aspects: target, sausage, and pseudokidney.

RESULTS

Surgery confirmed the CT diagnosis of intussusception in 9/10 patients; in the patient with transient intussusception a spontaneous resolution was confirmed at follow up CT after 24 h. In the 10 patients studied the following CT aspects were observed in the bowel involved by intussusception: a target aspect in 4 patients; a sausage aspect in 4 patients; in one of them a peritoneal effusion was also present; a pseudokidney aspect was observed in 2 patients, with a long tract intussusception and peritoneal adipose tissue; in both a hyperdensity of the peritoneal adipose tissue and enlarged vessels, that were herniated within the lumen of the bowel, were recognized. At surgey the causes of intestinal intussusception were: malignant tumors of the colon (4 cases), hamartomatous polyps of the small bowel (2 cases), mixoid fibrolipoma of the colon (one case), leiomyoma of the distal ileum (one case). In one patient no cause could be identified at CT, but the condition was found to co-exist with acute appendicitis at surgery.

CONCLUSIONS

CT is an accurate technique in the evaluation of intestinal intussusception in adults. It allows to identify the condition, its site, and sometimes the type of the lesion causing the intussusception, and any vascular alteration, thus playing an important role in establishing the most appropriate therapeutic strategy.

Retroaortic left renal vein joining the left common iliac vein

Retroaortic left renal vein joining the left common iliac vein is a rare congenital anomaly in the development of the inferior vena cava. To our knowledge, only one case has been reported in the literature; however, its imaging features have never been described. A 27-year-old male presented with a 1-year history of recurrent right flank pain, dysuria, hematuria, and fever (39 degrees C). Computed tomography and MR venography showed a retroaortic left renal vein joining the left common iliac vein. We present the CT and MR venography findings and discuss their feasibility in showing this congenital anomaly.

A new consensus error grid to evaluate the clinical significance of inaccuracies in the measurement of blood glucose

OBJECTIVE

The objectives of this study were 1) to construct new error grids (EGs) for blood glucose (BG) self-monitoring by using the expertise of a large panel of clinicians and 2) to use the new EGs to evaluate the accuracy of BG measurements made by patients.

RESEARCH DESIGN AND METHODS

To construct new EGs for type 1 and type 2 diabetic patients, a total of 100 experts of diabetes were asked to assign any error in BG measurement to 1 of 5 risk categories. We used these EGs to evaluate the accuracy of self-monitoring of blood glucose (SMBG) levels in 152 diabetic patients. The SMBG data were used to compare the new type 1 diabetes EG with a traditional EG.

RESULTS

Both the type 1 and type 2 diabetes EGs divide the risk plane into 8 concentric zones with no discontinuities. The new EGs are similar to each other, but they differ from the traditional EG in several significant ways. When used to evaluate a data set of measurements made by a sample of patients experienced in SMBG, the new type 1 diabetes EG rated 98.6% of their measurements as clinically acceptable, compared with 95% for the traditional EG.

CONCLUSIONS

The consensus EGs furnish a new tool for evaluating errors in the measurement of BG for patients with type 1 and type 2 diabetes.

Role Of Injection Technique In Use Of Insulin Pens: Prospective Evaluation Of A 31-Gauge, 8-Mm Insulin Pen Needle

OBJECTIVE

To evaluate the effectiveness, comfort, and ease of use of insulin pen injections with a 31-gauge, 8-mm needle.

METHODS

In 50 study subjects (24 patients with type 1 insulin-dependent diabetes and 26 insulin-using patients with type 2 diabetes), we assessed the delivery of insulin, residual insulin leakage, glycemic control, plunger depression pressure, and perceived pain associated with the B-D 31-gauge, 8-mm pen needles in comparison with the B-D conventional 30-gauge, 8-mm pen needles, while the patient used their own insulin pens (Novo or B-D). The study subjects injected their usual dose of regular and NPH insulin using the 30-gauge, 8-mm needle during the first 3 weeks of the study. This period was followed by two 3-week crossover segments of the study with either needle assigned in random sequence.

RESULTS

No statistically significant differences were noted in glycemic control or perceived pain of injection between the two needles. The interaction between the two needles and the two insulin pen brands on glycemic control was not statistically significant. Plunger depression pressure increased with the increase in the gauge of the needle and with increases in size of dose of injected insulin (P<0.01). B-D pen users reported lower plunger pressure ratings in comparison with Novo pen users (P<0.01), regardless of the needle type and dose range. Both the insulin pen type and the needle type individually had statistically significant (P<0.01) effects on the residual insulin leakage from the needle tip after injection; however, their interaction was not statistically significant. Insulin doses greater than 30 units were associated with increased leakage (P<0.01). As needle retention time decreased, residual insulin leakage from the needle tip after injection increased (P<0.01), regardless of the needle used.

CONCLUSION

The 31-gauge insulin pen needles are safe and effective for the delivery of insulin. With both 30-gauge and 31-gauge needles, attention to injection technique is essential to ensure complete delivery of insulin, particularly with administration of large doses.