Neonatal Bartter syndrome diagnosed by rapid genomics following low risk pre-conception carrier screening.

Advances in the speed and accessibility of genomic sequencing are broadening the application of this technology to rapid, acute care diagnostics and pre-conception carrier screening. In both circumstances, genetic counselling plays a critical role in preparing couples for the strengths and limitations of the testing. For pre-conception carrier screening in particular, it is important that parents and clinicians are aware that even in the absence of an identified risk for recessive disease, a baby with a genetic condition may still be conceived. As an example, we present the genomic journey of a couple who underwent pre-conception carrier screening and following a low-risk result, delivered a baby boy who was diagnosed with Type 1 Bartter syndrome. Ultra-rapid, post-natal, trio whole genome sequencing resolved both parents as carriers of pathogenic variants in SLC12A1, a gene not included in the original pre-conception screening panel. This family's story highlights (i) the intricacy of gene selection for pre-conception screening panels, (ii) the benefits of high-quality pre-test genetic counselling in supporting families through adverse genomic findings and (iii) the role rapid genomics can play in resolving uncertainty for families and clinicians in circumstances where suspicion of genetic disease exists. This article is accompanied by a Patient Voice perspective written by the child's parents, placing emphasis on the essential role genetic counselling played in their journey.

Predictive genetic testing for neurodegenerative conditions: how should conflicting interests within families be managed?

Predictive genetic testing for a neurodegenerative condition in one individual in a family may have implications for other family members, in that it can reveal their genetic status. Herein a complex clinical case is explored where the testing wish of one family member was in direct conflict to that of another. The son of a person at 50% risk of an autosomal dominant neurodegenerative condition requested testing to reveal his genetic status. The main reason for the request was if he had the familial mutation, he and his partner planned to utilise preimplantation genetic diagnosis to prevent his offspring having the condition. His at-risk parent was clear that if they found out they had the mutation, they would commit suicide. We assess the potential benefits and harms from acceding to or denying such a request and present an approach to balancing competing rights of individuals within families at risk of late-onset genetic conditions, where family members have irreconcilable differences with respect to predictive testing. We argue that while it may not be possible to completely avoid harm in these situations, it is important to consider the magnitude of risks, and make every effort to limit the potential for adverse outcomes.

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.

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.

"There's a whole different way of working with adolescents": interviews with Australian Genetic Counselors about their experiences with adolescent clients.

Adolescence is a developmental period marked by unique physical, psychological and social changes. Guidelines about working with adolescents are available to health professionals in other fields, yet few resources are tailored specifically to genetic counselors. The current qualitative study explored the experiences of genetic counselors who work with adolescent clients to determine whether challenges exist and if further training and support are needed. Semi-structured interviews were conducted with 11 genetic counselors from Australia. Interview transcripts were analyzed using thematic analysis from which 7 key themes emerged: 1) Adolescents: A distinct client group? 2) Characteristics of adolescents; 3) Strategies for working with adolescents; 4) Confidentiality; 5) Parental involvement and presence in sessions; 6) Benefits of working with adolescents; and 7) The effectiveness of past training and education. The findings hold important implications for clinical practice and may inform future training programs and guidelines for genetic counselors internationally.

Implementing Interventions to Address Gender and Power Inequalities in Early Adolescence: Utilizing a Theory of Change to Assess Conditions for Success.

PURPOSE: To create a set of criteria to assess facilitators and barriers to implementation among gender transformative interventions that target very young adolescents (VYAs) across different cultural settings. METHODS: Interventionists and researchers involved in the Global Early Adolescent Study created a Theory of Change (ToC) based on summarizing intervention components from five different gender transformative intervention curricula. Embedded within the ToC is a set of criteria labeled, 'Conditions of Success' which were developed to illustrate that change cannot happen unless interventions are implemented successfully. To test the feasibility of these criteria, implementation data collected across the five interventions in Global Early Adolescent Study were mapped onto the 'Conditions for Success' criteria and used to identify common facilitators and barriers to implementation. RESULTS: Using the 'Conditions for Success' criteria, we found that gender transformative interventions targeting VYAs were most challenged in meeting program delivery and facilitation conditions and needed to build more multisectoral support to shift rigid gender norms. Parents and caregivers also needed to be engaged in the program either as a separate target population or as codesigners and implementers for the interventions. DISCUSSION: The Conditions for Success criteria provide a useful framework for assessing facilitators and barriers to implementation among gender transformative interventions for VYAs. Additional research is underway to examine whether interventions that meet more conditions of success result in greater program impact, which will be used to further refine the overall ToC.

Cost Analysis of Community-Based Violence Prevention Programs: Manhood 2.0 and Job Skills Programs.

Purpose: Sexual violence (SV) and adolescent relationship abuse (ARA) are common in the U. S. and have strong associations with negative health and wellbeing outcomes. Manhood 2.0 is the first U.S. program designed for community settings to build bystander skills while also challenging harmful gender norms. A cluster-randomized trial comparing Manhood 2.0 to Job Skills, a job readiness training control condition, demonstrated that it is a promising strategy to prevent sexual violence and adolescent relationship abuse. Such community-based interventions may be particularly relevant in lower resource urban settings, and the costs of such prevention programs have not been considered previously. Methods: The aim of the present study is to perform systematic and standardized cost calculations associated with implementing Manhood 2.0 among adolescent males. In addition, this study provides detailed cost information of the community-based intervention program, as well as costs associated with implementing the Job Skills control program. Program implementation data were recorded throughout the study period (2015-2019) by the Manhood 2.0 study team. Results: The cost of implementing Manhood 2.0 is $4,771 per complete round of program delivery and $451 per participant, which is approximately the same cost as the control Job Skills program ($4,432 and $453 per participant). The marginal cost per additional round of Manhood 2.0 program is $3,682. Conclusion: Implementation of a community-based program requires substantial resources and collaborations with community partners especially in economically disadvantaged neighborhoods. This study provides a snapshot of the cost information of a community-based intervention program from the implementing agency's perspective, which is essential in helping decision-makers understand the costs they will incur by implementing prevention programs and ensuring program feasibility and sustainability.

Consumer strategies for coping with antipsychotic medication side effects.

OBJECTIVE: This study was designed to investigate the strategies employed by consumers to manage the common side effects associated with antipsychotic medication use. METHOD: Focus group discussions and individual interviews involving 238 consumers, 25 carers and 16 mental health staff were employed to identify key side effects and a range of consumer coping strategies for managing these adverse effects. RESULTS: Nine side effects were selected from a total pool of 32 proposed in the group discussions. Strategies that were perceived by the participants to be useful in coping with the selected side effects were then identified. CONCLUSIONS: While the strategies proposed for each side effect differed, common themes included the maintenance of a balanced lifestyle, healthy eating and sleeping routines, and fostering a positive outlook on life. Understanding the strategies employed by consumers to deal with the adverse effects of their medications may help clinicians to engage more effectively with consumers in the discussion and management of side effects.

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.

Dig deeper when it does not make sense: Juvenile xanthomas due to sitosterolemia.

Sitosterolemia is an extremely rare autosomal recessive disease caused by mutations in either ABCG5 or ABCG8, which encode for a sterol efflux transporter (sterolin) that pumps sterols out into the intestinal lumen or into bile. This leads to progressive accumulation of plant sterols in blood and tissues. Clinical presentation is variable and may include xanthoma, arthritis, thyroid dysfunction, premature atherosclerotic disease, splenomegaly, and hematologic manifestations. We report a child presented with multiple xanthomas at age 5.5 years, located on the elbow, knee, and toe. Juvenile xanthogranuloma was considered based on histopathologic findings. At 8 years of age, a lipid profile showed markedly elevated total cholesterol (9.4 mmol/L) and low-density lipoprotein cholesterol (LDL-C, 7.4 mmol/L). Simvastatin therapy was initiated, however, the lipid profile was persistently abnormal. At age 8.5 years, genetic testing identified two novel variants: (NM_022437.3[ABCG8]:c.1444del;p.Leu482Trpfs*40) and (NM_022437.3[ABCG8]:c.1640T>C;p.Leu547Pro) in the ABCG8 gene. Plasma sitosterol was subsequently found to be very high, confirming the diagnosis. She was started on a low plant sterol and cholesterol diet for 6 weeks with insignificant response and therefore ezetimibe (10 mg daily) was added. This resulted in significant reduction of cholesterol, LDL, sitosterol levels, and no further increase in the size of the xanthomas. This case emphasizes the diagnostic odyssey, the benefits of genomic testing and importance of a correct diagnosis in order to initiate appropriate therapy. It also illustrates the importance of considering rare conditions, such as sitosterolemia, as a differential diagnosis in patients with hypercholesterolemia and increased LDL-C.

Male Adolescents' Gender Attitudes and Violence: Implications for Youth Violence Prevention.

INTRODUCTION: This study analyzed the associations among male adolescents' gender attitudes, intentions to intervene, witnessing peers' abusive behaviors, and multiple forms of adolescent violence perpetration. This community-based evaluation aims to inform future youth violence prevention efforts through the identification of potential predictors of interpersonal violence perpetration. METHODS: Cross-sectional data were from baseline surveys conducted with 866 male adolescents, aged 13-19 years, from community settings in 20 lower-resource neighborhoods in Pittsburgh, PA (August 2015 - June 2017), as part of a cluster RCT to evaluate a sexual violence prevention program. Participants completed in-person, anonymous electronic surveys about gender attitudes, bystander intentions, witnessing peers' abusive behaviors, violence perpetration, and demographics. The analysis was conducted between 2018 and 2019. RESULTS: The youth identified mostly as African American (70%) or Hispanic, multiracial, or other (21%). Most (88%) were born in the U.S., and 85% were in school. Youth with more equitable gender attitudes had lower odds of self-reported violence perpetration across multiple domains, including dating abuse (AOR=0.46, 95% CI=0.29, 0.72) and sexual harassment (AOR=0.50, 95% CI=0.37, 0.67). The relationship between intentions to intervene and violence perpetration was inconclusive. Witnessing peers engaged in abusive behaviors was associated with increased odds of multiple types of violence perpetration, such as dating abuse (witnessed 3 or more behaviors, AOR=2.41, 95% CI=1.31, 4.44). CONCLUSIONS: This is the first U.S.-based study to elicit information from male adolescents in community-based settings (rather than schools or clinics) about multiple types of interpersonal violence perpetration. Findings support violence prevention strategies that challenge harmful gender and social norms while simultaneously increasing youths' skills in interrupting peers' disrespectful and harmful behaviors.

Effect of a Community-Based Gender Norms Program on Sexual Violence Perpetration by Adolescent Boys and Young Men: A Cluster Randomized Clinical Trial.

Importance: Engaging adolescent boys and young men in preventing violence against women is a potentially impactful public health strategy. Objective: To evaluate the effectiveness of a community-based, gender-transformative program (ie, Manhood 2.0) on perpetration of gender-based violence by adolescent boys and young men. Design, Setting, and Participants: In this unblinded cluster randomized clinical trial, neighborhoods were designated as the unit of clustering (1:1 allocation). Three-month (ie, time point 2 [T2]) and 9-month (ie, time point 3 [T3]) follow-ups were conducted. The trial took place in 20 Pittsburgh, Pennsylvania, neighborhoods and 1 centrally located site with concentrated disadvantage. Pittsburgh-based adolescent boys and young men (ages 13 to 19 years) were recruited between July 27, 2015, and June 5, 2017, through youth-serving organizations and community-based alternatives to residential placement for juvenile justice-involved youth. Intention-to-treat analysis was conducted from June 2018 to November 2019. Interventions: Manhood 2.0, an international program adapted for adolescent boys and young men in US urban communities, encourages these individuals to challenge gender norms that foster violence against women and unhealthy sexual relationships. Individuals in the control population received job-readiness training. Each program was 18 hours. Main Outcomes and Measures: The primary outcome was change in participant-level perpetration of sexual violence (SV) or adolescent relationship abuse (ARA) at T3. Results: Among 866 participants, 465 individuals (54%) enrolled in 11 intervention clusters and 401 individuals (46%) enrolled in 10 control clusters. In the intervention group, 325 participants (70%) were analyzed at T2 and 334 participants (72%) were analyzed at T3; in the control group, 262 participants (65%) were analyzed at T2 and 301 participants (75%) were analyzed at T3. Mean (SD) age was 15.5 (1.6) years; 609 participants (70%) self-identified as non-Hispanic Black, and 178 (20%) self-identified as Hispanic, multiracial, or other race/ethnicity other than White. Among individuals in the intervention group, 296 participants (64%) reported any SV or ARA perpetration at baseline, and 173 participants (52%) reported any SV or ARA perpetration at T3. Among individuals in the control group, 213 participants (53%) reported any SV or ARA perpetration at baseline, and 124 participants (41%) reported any SV or ARA perpetration at T3). The difference in reduction between groups was not significant. There was no evidence of an intervention effect for the primary outcome (adjusted odds ratio [OR], 1.32; 95% CI, 0.86-2.01; P = .20). Conclusions and Relevance: The findings from this evaluation of a community-based gender-transformative program for adolescent boys and young men did not show a significant intervention effect in reducing SV or ARA perpetration between Manhood 2.0 and a job-readiness control program. Combining gender-transformative approaches with job-readiness programs may be relevant for violence prevention in low-resource urban settings. Attention to improving implementation and strategies to sustain such community-based efforts are needed. Trial Registration: ClinicalTrials.gov Identifier: NCT02427061.

Adapting a Global Gender-Transformative Violence Prevention Program for the U.S. Community-Based Setting for Work with Young Men.

Extensive practice-based evidence from international settings, as well as in-depth evaluations of programs promoting gender equity, have demonstrated effectiveness in reducing perpetration of violence against women and girls. Such "gender-transfor-mative programs" encourage critical analysis of gender norms, challenge homophobia and gender-based harassment, build skills to question harmful masculine norms, interrupt harmful and disrespectful behaviors, and encourage more equitable behaviors. Here we describe the history of a gender-transformative program, "Program H," first developed in Brazil and Mexico, the rationale for and evaluation of this original program, and the processes of adaptation for the US urban community-based setting, and highlight the risks as well as opportunities on the work with young men and boys in the future.

Engendering healthy masculinities to prevent sexual violence: Rationale for and design of the Manhood 2.0 trial.

Violence against women and girls is an important global health concern. Numerous health organizations highlight engaging men and boys in preventing violence against women as a potentially impactful public health prevention strategy. Adapted from an international setting for use in the US, "Manhood 2.0" is a "gender transformative" program that involves challenging harmful gender and sexuality norms that foster violence against women while promoting bystander intervention (i.e., giving boys skills to interrupt abusive behaviors they witness among peers) to reduce the perpetration of sexual violence (SV) and adolescent relationship abuse (ARA). Manhood 2.0 is being rigorously evaluated in a community-based cluster-randomized trial in 21 lower resource Pittsburgh neighborhoods with 866 adolescent males ages 13-19. The comparison intervention is a job readiness training program which focuses on the skills needed to prepare youth for entering the workforce, including goal setting, accountability, resume building, and interview preparation. This study will provide urgently needed information about the effectiveness of a gender transformative program, which combines healthy sexuality education, gender norms change, and bystander skills to interrupt peers' disrespectful and harmful behaviors to reduce SV/ARA perpetration among adolescent males. In this manuscript, we outline the rationale for and evaluation design of Manhood 2.0. Clinical Trials #: NCT02427061.

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.

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.

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.

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 and user performance evaluation of the Contour(®) Next Link 2.4 blood glucose monitoring system.

BACKGROUND: The Contour(®) Next Link 2.4 blood glucose monitoring system (BGMS), which communicates wirelessly exclusively with a Medtronic insulin pump, was assessed in 2 separate studies. METHODS: In the laboratory study (N=100), subject capillary fingertip samples were tested in duplicate using 3 test strip lots; accuracy was assessed based on ISO 15197:2013 section 6.3 accuracy criteria (95% within ±15mg/dl or ±15% of reference for glucose <100 and ≥100mg/dl, respectively). In the clinical trial (N=219), untrained subjects with diabetes tested capillary fingertip and palm blood samples and completed an ease-of-use questionnaire. BGMS and YSI glucose analyzer results were compared based on ISO 15197:2013 section 8 accuracy criteria. RESULTS: In the laboratory study, 100% of results met ISO 15197:2013 section 6.3 accuracy criteria. In the clinical trial, 98.6% of capillary fingertip and 97.2% of palm results from subjects met ISO 15197:2013 section 8 accuracy criteria. By Parkes-Consensus Error Grid analysis, 100% of subject capillary fingertip results were within Zone A. Based on questionnaire results, the majority of subjects found the BGMS easy to use. CONCLUSIONS: The BGMS exceeds ISO 15197:2013 section 6.3 and section 8 accuracy criteria in the laboratory and in the hands of untrained users with diabetes.