Variation in Point-of-Care Testing of HbA1c in Diabetes Care in General Practice

Point-of-Care testing of HbA1c levels in community settings for people with established diabetes or people at risk of developing diabetes: A systematic review and meta-analysis

BACKGROUND

Glycated haemoglobin (HbA1c) measurement using Point of Care (POC) testing may be of huge utility, providing convenient testing for early diagnosis and regular monitoring of hard-to-reach patient groups. This systematic review aimed to identify evidence for the successful deployment of these devices to improve patient outcomes in diabetes.

METHODS

A systematic review and meta-analysis was undertaken in February 2023, to identify all relevant articles: (CINAHL, Cochrane, PubMed, Scopus, and Web of Science). Studies were included if they reported outcomes of community POC testing for HbA1c for people with diabetes or at risk of diabetes. The Prospero database and trial registers were searched. Only English language articles were included. Title, abstract screening and full text review was carried out by two reviewers (AG/AR). The Cochrane risk of bias tool for randomised studies and the NIH Quality Assessment tool for observational cohort and cross-sectional studies were used. Publication bias was assessed visually using funnel plot and statistical assessment. We performed a meta-analysis on appropriate studies, applying a fixed effect model. We investigated heterogeneity using visual inspection of forest plots along with evaluative approaches (χ2, I2). Strength of evidence was assessed using GRADE.

FINDINGS

24 studies fulfilled the criteria to be included in the narrative synthesis and 5 could be included in quantitative analysis. 13 studies evaluated HbA1c POC testing in non-diabetic patients, 9 reported results for diabetic patients and 2 included both groups. The narrative synthesis was constructed around 6 key themes: increased test access, diagnosis of people who would otherwise go undiagnosed, intervention/lifestyle change, POC testing effect on HbA1c and glycaemic control, follow-up time and patient satisfaction.

INTERPRETATION

The available published data supports the proposed use of POC devices in a community setting, with positive effects on diabetic care with limited evidence that patients can achieve better glycaemic control.

Lot variation and inter-device differences contribute to poor analytical performance of the DCA Vantage™ HbA1c POCT instrument in a true clinical setting

OBJECTIVES

The glycated haemoglobin fraction A_1c (HbA_1c) is widely used in the management of diabetes mellitus, and the Siemens DCA Vantage™ point-of-care testing (POCT) instrument offers rapid HbA_1c results even far from a clinical laboratory. However, the analytical performance has been questioned, and not much is known about effects of changing reagent lot, instrument and operator. We therefore compared the analytical performance of the DCA Vantage™ with established routine methods (Tosoh G8/G11 ion exchange HPLC) in a true clinical setting at two Danish hospitals.

METHODS

We extracted all routine clinical HbA_1c results incidentally drawn from the same patient within 48 h (n=960 pairs) and evaluated the effect of reagent lot, operator and instrument. We also performed a prospective method comparison in our diabetes out-patient clinic (n=97).

RESULTS

The critical difference (CD) between two POCT results varied between 5.14 and 6.61 mmol/mol (0.47-0.55%), and the analytical imprecision of the DCA Vantage™ (CV_A) was >3%. Significant effect of reagent lot and inter-instrument differences were found, whereas no effect of operator was seen.

CONCLUSIONS

The DCA Vantage™ HbA_1c analysis does not fulfil the prevailing analytical performance specifications, but rigorous validation of new reagent lots and continuous recalibration of instruments may potentially improve the precision substantially. Our findings, therefore, clearly emphasise the necessity of a close collaboration between clinicians and laboratory professionals in the POCT field. Finally, POCT HbA_1c results should always be interpreted together with other measures of glycaemic control to avoid inappropriate change of patient treatments due to measurement uncertainty.

Countrywide survey on utilization of medical devices by GPs in Hungary: advantages of the cluster-practice model

BACKGROUND

Expectations towards general practitioners (GPs) are continuously increasing to provide a more systematic preventive- and definitive-based care, a wider range of multidisciplinary team-based services and to integrate state-of-the-art digital solutions into daily practice. Aided by development programmes, Hungarian primary care is facing the challenge to fulfil its role as the provider of comprehensive, high quality, patient-centred, preventive care, answering the challenges caused by non-communicable diseases (NCDs).

AIM

The article aims to provide an insight into the utilization of simple, digital, medical devices. We show the relationship between the primary health care (PHC) practice models and the used types of devices. We point at further development directions of GP practices regarding the utilization of evidence-based medical technologies and how such devices support the screening and chronic care of patients with NCDs in everyday practice.

METHODS

Data were collected using an online self-assessment questionnaire from 1800 Hungarian GPs registered in Hungary. Descriptive statistics, Wilcoxon's test and χ2 test were applied to analyze the ownership and utilization of 32 types of medical devices, characteristics of the GP practices and to highlight the differences between traditional and cluster-based operating model.

FINDINGS

Based on the responses from 27.7% of all Hungarian GPs, the medical device infrastructure was found to be limited especially in single GP-practices. Those involved in development projects of GP's clusters in the last decade reported a wider range and significantly more intensive utilization of evidence-based technologies (average number of devices: 5.42 versus 7.56, P<.001), but even these GPs are not using some of their devices (e.g., various point of care testing devices) due to the lack of financing. In addition, GPs involved in GPs-cluster development model programmes showed significantly greater willingness for sharing relatively expensive, extra workforce-demanding technologies (χ2 = 24.5, P<.001).

Effects of Point-Of-Care Testing in General Practice for Type 2 Diabetes Patients on Ambulatory Visits and Hospitalizations

Point-of-care testing (POCT) of HbA1c means instant test results and more coherent counseling that is expected to improve diabetes management and affect ambulatory visits and hospitalizations. From late 2008, POCT has been implemented and adopted by a segment of the general practices in the capital region of Denmark. The aim of this study is to assess whether the introduction of POCT of HbA1c in general practice (GP) has affected patient outcomes for T2 diabetes patients in terms of hospital activity. We apply difference-in-differences models at the GP clinic level to assess the casual effects of POCT on the following hospital outcomes: (1) admissions for diabetes, (2) admissions for ambulatory care sensitive diabetes conditions (ACSCs), (3) ambulatory visits for diabetes. The use of POCT is remunerated by a fee, and registration of this fee is used to measure the GP’s use of POCT. The control group includes clinics from the same region that did not use POCT. The sensitivity of our results is assessed by an event study approach and a range of robustness tests. The panel data set includes 553 GP clinics and approximately 30,000 diabetes patients from the capital region of Denmark, observed in the years 2004–2012. We find that voluntary adoption of POCT of HbA1c in GP has no effect on hospital admissions and diabetes-related hospital ambulatory visits. Event study analysis and different treatment definitions confirm the robustness of these results. If implementation of POCT of HbA1c improves other parts of diabetes management as indicated in the literature, it seems worthwhile to implement POCT of HbA1c in the capital region of Denmark. However, doubts around the quality of POCT of HbA1c testing and a desire to capture data at central labs may prevent implementation of more value based HbA1c testing.

Point-of-care testing in primary care: A systematic review on implementation aspects addressed in test evaluations

OBJECTIVES

There are numerous point-of-care tests (POCTs) available on the market, but many of these are not used. This study reviewed literature pertaining to the evaluation/usage of POCTs in primary care, to investigate whether outcomes being reported reflect aspects previously demonstrated to be important for general practitioners (GPs) in the decision to implement a POCT in practice.

METHODS

Scopus and Medline were searched to identify studies that evaluated a POCT in primary care. We identified abstracts and full-texts consisting of applied studies (eg trials, simulations, observational studies) and qualitative studies (eg interviews, surveys). Data were extracted from the included studies, such as the type of study, the extent to which manufacturers were involved in the study, and the biomarker/assay measured by the test(s). Studies were evaluated to summarise the extent to which they reported on, amongst others, clinical utility, user-friendliness, turnaround-time and technical performance (aspects previously identified as important).

RESULTS

The initial search resulted in 1398 publications, of which 125 met the inclusion criteria. From these studies, 83 POCTs across several disease areas (including cardiovascular disease, venous thromboembolism and respiratory-tract-infections) were identified. There was an inconsistency between what is reported in the studies and what GPs consider important. GPs perceive clinical utility as the most important aspect, yet this was rarely included explicitly in test evaluations in the literature, with only 8% of evaluations incorporating it in their analysis/discussion.

CONCLUSIONS

This review showed that, despite the growing market and development of new POCTs, studies evaluating such tests fail to report on aspects that GPs find important. To ensure that an evaluation of a POCT is useful to primary care clinicians, future evaluations should not only focus on the technical performance aspects of a test, but also report on the aspects relating to the clinical utility and risks.

Does changed referral options affect the use of MRI for patients with low back pain? Evidence from a natural experiment using nationwide data

OBJECTIVES

This study reports lumbar MRI referral patterns in the Region of Southern Denmark (RSD) and investigates the hypothesis that we will see an increase in imaging rates (MRI rates) following new referral options to lumbar MRI in the RSD in comparison with the other regions in Denmark from 2010 to 2013.

DESIGN

A difference-in-difference (DD) analysis, using general practitioners (GPs) in other regions as control, was used to test if the new referral options had an effect on the MRI rates.

SETTING

In 2010, RSD introduced organisational changes affecting the referral options for lumbar MRI. First, the possibility for direct referral to lumbar MRI was introduced GPs, and second, the region gathered all local spine departments into one specialist hospital called the Spine Centre.

PARTICIPANTS

We retrieved all lumbar MRIs performed on patients aged 18+ performed on Danish hospitals from 2008 to 2013 using the registries from Statistics Denmark. We use sociodemographic information from all Danish citizens aged 18+ aggregated to GP level. Primary and secondary outcome measures: lumbar MRI scans per 1000 capita enlisted with a GP (MRI rates) were calculated based on GPs patient list. Four referral types were made to describe changes in referral patterns.

RESULTS

In total 183 389 patients received 240 760 lumbar MRIs in the period. The use of the direct referral option by GPs in the RSD increased by 115% in the period from 2010 to 2013 and accounted for 34% of all referrals (n=6545) in 2013. MRI rates were significantly higher in RSD following the organisational changes (DD 1.389(0.925-1.852) lumbar MRI per 1.000 enlisted with a GP).

CONCLUSIONS

Introduction of organisational changes in RSD as direct referral to lumbar MRI from GPs and chiropractors as well as establishing a Spine Centre increase the lumbar MRI rate in comparison with other regions in Denmark.