Accuracy of five plasma calibrated glucometers to screen for and diagnose gestational diabetes mellitus in a low resource clinic setting

Impact of hematocrit levels on the accuracy of specific blood glucose meters: A hospital-based study

AIMS/INTRODUCTION

Blood glucose meters are commonly used at the bedside, but most of the meters used in Hung Vuong Hospital (Ho Chi Minh City, Vietnam) are built for self-monitoring and might not be suitable for determining glucose levels in patients. In this study, we aimed to validate the performance of six frequently used meters in our hospital using the Clinical & Laboratory Standards Institute (CLSI) standard, and investigate the hematocrit impact on the accuracy of these meters.

MATERIALS AND METHODS

A total of 135 pregnant women who underwent a 75-g oral glucose tolerance test consented to participate in the study at Hung Vuong Hospital. Whole blood glucose levels were measured in duplicate using meters, and hematocrit levels were measured using an Alinity h-series analyzer. Within 5 min, plasma glucose levels were measured twice in a row using the Cobas c502 reference analyzer. For accuracy and precision, the hematocrit effect was assed using CLSI POCT12-A3.

RESULTS

Out of six evaluated meters, three meters qualified. For CLSI criterion at glucose concentration of 5.55 mmol/L, Accu-Chek Inform II, Accu-Chek Performa and OneTouch VerioVue achieved 97.31%, 98.08% and 99.62%, respectively. For CLSI criterion at 4.17 mmol/L, these three achieved 100%. Accu-Chek Inform II and Accu-Chek Performa showed an inverse correlation between glucose level and hematocrit with slopes of -0.500 (95% confidence interval -0.678 to -0.322) and -0.396 (95% confidence interval -0.569 to -0.224), whereas OneTouch VerioVue was not affected by hematocrit, with a slope of 0.207 (95% confidence interval -0.026 to 0.440).

CONCLUSIONS

Blood glucose meters' measurements can be affected by hematocrit, and might provide readings not within an acceptable bias. Medical organizations need to verify or validate before using on patients.

Availability and pricing of insulin and related diagnostics in South Africa

Background

In South Africa (SA), most patients rely on the government for free healthcare. Some choose to subscribe to a medical insurance scheme. If insulin is unavailable in government or otherwise unaffordable, non-adherence may occur, which can increase complications of the disease.

Methods

Data on availability and pricing of insulin and related diagnostics was collected from SA pharmacies via an online survey. Co-payments levied on insulin by the biggest medical aids were extracted from formularies. Affordability of these items was then assessed. An adapted methodology from the World Health Organization/Health Action International tool was used.

Results

There was fairly high availability of insulin in the public sector, with the exception of long-acting insulin which respondents claimed was difficult to find; however, long-acting insulin glargine was available in most private sector pharmacies. Point-of-care (POC) blood glucose testing was free in the public sector but offered in only 31.25% of pharmacies. Patients pay a minimum of USD 40.4 (over 3 days' wages for the lowest paid government worker (LPGW)) for a months' supply of the cheapest insulin, needles and test strips. Insulin in SA was cheaper than 5 other countries, except Australia.

Conclusion

Overall, there is a good availability of insulin and related diagnostics in SA. Even though insulin is cheaper than other countries, it is unaffordable to the LPGW. This highlights the importance of ensuring a constant availability of insulin in the free public sector. Whilst human insulins are cheaper than newer analogue insulins and SA faces cost constraints, important variables in favour of newer insulins, such as ease-of-use, long term outcomes and value should be considered when treatment guidelines are updated. Annual POC testing should be available and offered free to all patients to detect diabetes early.

Integrated health system intervention aimed at reducing type 2 diabetes risk in women after gestational diabetes in South Africa (IINDIAGO): a randomised controlled trial protocol

INTRODUCTION

South Africa has a high prevalence of gestational diabetes mellitus (GDM; 15%) and many of these women (48%) progress to type 2 diabetes mellitus (T2DM) within 5 years post partum. A significant proportion (47%) of the women are not aware of their diabetes status after the index pregnancy, which may be in part to low postnatal diabetes screening rates. Therefore, we aim to evaluate a intervention that reduces the subsequent risk of developing T2DM among women with recent GDM. Our objectives are fourfold: (1) compare the completion of the nationally recommended 6-week postpartum oral glucose tolerance test (OGTT) between intervention and control groups; (2) compare the diabetes risk reduction between control and intervention groups at 12 months' post partum; (3) assess the process of implementation; and (4) assess the cost-effectiveness of the proposed intervention package.

METHODS AND ANALYSES

Convergent parallel mixed-methods study with the main component being a pragmatic, 2-arm individually randomised controlled trial, which will be carried out at five major referral centres and up to 26 well-baby clinics in the Western Cape and Gauteng provinces of South Africa. Participants (n=370) with GDM (with no prior history of either type 1 or type 2 diabetes) will be recruited into the study at 24-36 weeks' gestational age, at which stage first data collection will take place. Subsequent data collection will take place at 6-8 weeks after delivery and again at 12 months. The primary outcome for the trial is twofold: first, the completion of the recommended 2-hour OGTT at the well-baby clinics 6-8 weeks post partum, and second, a composite diabetes risk reduction indicator at 12 months. Process evaluation will assess fidelity, acceptability, and dose of the intervention.

ETHICS AND DISSEMINATION

Ethics approval has been granted from University of Cape Town (829/2016), University of the Witwatersrand, Johannesburg (M170228), University of Stellenbosch (N17/04/032) and the University of Montreal (2019-794). The results of the trial will be disseminated through publication in peer-reviewed journals and presentations to key South African Government stakeholders and health service providers.

PROTOCOL VERSION

1 December 2022 (version #2). Any protocol amendments will be communicated to investigators, Human Ethics Research Committees, trial participants, and trial registries.

TRIAL REGISTRATION NUMBER

PAN African Clinical Trials Registry (https://pactr.samrc.ac.za) on 11 June 2018 (identifier PACTR201805003336174).

Accuracy of capillary blood glucose for 50-g glucose challenge test for gestational diabetes screening

Purpose

To assess the accuracy of capillary blood glucose (CBG) compared to conventional venous plasma glucose (VPG) testing for 50-g glucose challenge test (GCT) in gestational diabetes (GDM) screening.

Methods

A total of 300 women were enrolled and 50-g GCT for GDM screening was offered. At 1 h after glucose loading, CBG was evaluated by CONTOUR® PLUS glucose meter by well-trained nurses immediately after venipuncture for VPG. Results of CBG were compared with those from VPG to evaluate its accuracy. Women with venous plasma glucose > 140 mg/dL were offered 100-g OGTT for GDM diagnosis.

Results

The mean age was 30.2 years and the mean gestational age at testing was 21.8 weeks. GDM was diagnosed in 34 women (11.3%). The mean VPG was 142.1 ± 32.9 mg/dL and the mean CBG was 129.3 ± 33.5 mg/dL. Mean difference was -12.3 ± 12.5 mg/dL, corresponding to -8.8 ± 11.4%. CBG significantly correlated with VPG with correlation coefficient of 0.929, p < 0.001. In the detection of abnormal 50-g GCT results (VPG ≥ 140 mg/dL), at 126 mg/dL cutoff, CBG had sensitivity of 92.5%, specificity of 81.8%, and positive and negative predictive values of 82.8%and 92%. None of the GDM would have been missed if CBG was used.

Conclusion

CBG by a certified glucose meter could be considered as an alternative to conventional VPG testing for 50-g GCT for GDM screening using 126 mg/dL cutoff value.

Health literacy and diabetes control in pregnant women

Background:

Low health literacy (HL) is associated with an extensive range of health outcomes.

Objective:

The present study was performed to inquire about the relationship between HL and glycemic control in gestational diabetes in order to design interventional future preventing programs.

Methods:

This cross-sectional study was performed on 104 Iranian pregnant women with gestational diabetes mellitus (GDM) referred from urban and rural areas to endocrinology clinic of Hamadan Beheshti Hospital, in 2017. Iranian Health Literacy Questionnaire (IHLQ) and a sociodemographic checklist were distributed among women. Correlation between HL and glycemic control was examined using SPSS. The significance level was set at P < 0.05.

Results:

Among women, 48.1% (50) were affected by uncontrolled diabetes and only 22% (11) had an adequate level of HL. An adequate level of HL were 50% and 22% in glycemic controlled and uncontrolled women, respectively. In univariate analysis, there was a significant relationship between diabetes control and adequate HL. So, problematic HL could increase the chance of uncontrolled diabetes more than three times (odds ratio: 3.5; CI: 1.5–8.3; P value: 0.004). Among all related variables, education and being housewife were considered as protective and risk factors for problematic HL, respectively.

Conclusion:

In conclusion, this study has provided evidence of limited HL and its relationship with low glycemic control in pregnant women with GDM. The problem was more serious in low educated, rural, housekeepers, and older-aged women. This deficit needs to be addressed by health planners and policymakers who are responsible for promoting the health of people and decreasing health inequalities community.

The impact of differences in plasma glucose between glucose oxidase and hexokinase methods on estimated gestational diabetes mellitus prevalence

We evaluated the extent of measurement discordance between glucose oxidase and hexokinase laboratory methods and the effect of this on estimated gestational diabetes mellitus (GDM) prevalence in a routine clinical setting. 592 consecutive urban African women were screened for GDM. Paired venous specimens were submitted to two independent calibrated laboratories that used either method to measure plasma glucose concentrations. World Health Organisation diagnostic criteria were applied. GDM prevalence determined by the glucose oxidase and hexokinase methods was 6.9% and 5.1% respectively. The overall GDM prevalence was 9%. Only 34% of GDM positive diagnoses were common to both laboratory methods. Bland Altman plots identified a bias of 0.2 mmol/l between laboratory methods. Plasma glucose concentrations measured by the glucose oxidase method were more platykurtic in distribution. Low diagnostic agreement between laboratory methods was further indicated by a Cohen's kappa of 0.48 (p < 0.001). Reports of GDM prevalence using either the glucose oxidase or hexokinase laboratory methods may not be truly interchangeable or directly comparable.