What determines the cost-effectiveness of diabetes screening?

Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

BACKGROUND

Numerous laboratory tests are used in the diagnosis and management of diabetes mellitus. The quality of the scientific evidence supporting the use of these assays varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for laboratory analysis in screening, diagnosis, or monitoring of diabetes. The overall quality of the evidence and the strength of the recommendations were evaluated. The draft consensus recommendations were evaluated by invited reviewers and presented for public comment. Suggestions were incorporated as deemed appropriate by the authors (see Acknowledgments). The guidelines were reviewed by the Evidence Based Laboratory Medicine Committee and the Board of Directors of the American Association for Clinical Chemistry and by the Professional Practice Committee of the American Diabetes Association.

CONTENT

Diabetes can be diagnosed by demonstrating increased concentrations of glucose in venous plasma or increased hemoglobin A1c (HbA1c) in the blood. Glycemic control is monitored by the people with diabetes measuring their own blood glucose with meters and/or with continuous interstitial glucose monitoring (CGM) devices and also by laboratory analysis of HbA1c. The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of ketones, autoantibodies, urine albumin, insulin, proinsulin, and C-peptide are addressed.

SUMMARY

The guidelines provide specific recommendations based on published data or derived from expert consensus. Several analytes are found to have minimal clinical value at the present time, and measurement of them is not recommended.

Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

BACKGROUND

Numerous laboratory tests are used in the diagnosis and management of diabetes mellitus. The quality of the scientific evidence supporting the use of these assays varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for laboratory analysis in screening, diagnosis, or monitoring of diabetes. The overall quality of the evidence and the strength of the recommendations were evaluated. The draft consensus recommendations were evaluated by invited reviewers and presented for public comment. Suggestions were incorporated as deemed appropriate by the authors (see Acknowledgments). The guidelines were reviewed by the Evidence Based Laboratory Medicine Committee and the Board of Directors of the American Association of Clinical Chemistry and by the Professional Practice Committee of the American Diabetes Association.

CONTENT

Diabetes can be diagnosed by demonstrating increased concentrations of glucose in venous plasma or increased hemoglobin A1c (Hb A1c) in the blood. Glycemic control is monitored by the people with diabetes measuring their own blood glucose with meters and/or with continuous interstitial glucose monitoring (CGM) devices and also by laboratory analysis of Hb A1c. The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of ketones, autoantibodies, urine albumin, insulin, proinsulin, and C-peptide are addressed.

SUMMARY

The guidelines provide specific recommendations based on published data or derived from expert consensus. Several analytes are found to have minimal clinical value at the present time, and measurement of them is not recommended.

Cost-Effectiveness of Screening to Identify Pre-Diabetes and Diabetes in the Oral Healthcare Setting

Background: This study assesses the long-term cost-effectiveness of this screening protocol from a healthcare system perspective. Methods: Australians presenting to private oral healthcare practices recruited to the iDENTify study were included as the study population. A Markov model preceded by a decision tree was developed to assess the intervention’s long-term cost-effectiveness when rolled out to all eligible Australians, and measured against ‘no-intervention’ current practice. The model consisted of four health states: normoglycaemia; pre-diabetes; type 2 diabetes and death. Intervention reach of various levels (10%, 20%, 30%, and 40%) were assessed. The model adopted a 30-year lifetime horizon and a 2020 reference year. Costs and benefits were discounted at 5% per annum. Results: If the intervention reached a minimum of 10% of the target population, over the lifetime time horizon, each screened participant would incur a cost of $38,462 and a gain of 10.564 QALYs, compared to $38,469 and 10.561 QALYs for each participant under current practice. Screening was associated with lower costs and higher benefits (a saving of $8 per person and 0.003 QALYs gained), compared to current standard practice without such screening. Between 8 and 34 type 2 diabetes cases would be avoided per 10,000 patients screened if the intervention were taken up by 10% to 40% of private oral healthcare practices. Sensitivity analyses showed consistent results. Conclusions: Implementing type 2 diabetes screening in the private oral healthcare setting using a simple risk assessment tool was demonstrated to be cost-saving. The wider adoption of such screening is recommended.

A systematic analysis on prevalence and sub-regional distribution of undiagnosed diabetes mellitus among adults in African countries

BACKGROUND

Despite the high prevalence of diabetes in Africa, the extent of undiagnosed diabetes in the region is still poorly understood. This systematic review and meta-analysis was designed to determine the pooled prevalence of undiagnosed diabetes mellitus among adults in Africa.

METHODS

We conducted a systematic desk review and electronic web-based search of PubMed, Google Scholar, EMBASE, and the World Health Organization's Hinari portal (which includes the SCOPUS, African Index Medicus, and African Journals Online databases), identifying peer-reviewed research studies on the prevalence of undiagnosed diabetes among adult individuals using pre-defined quality and inclusion criteria. We ran our search from June 1, 2018 to Jun 14, 2020. We extracted relevant data and presented descriptive summaries of the studies in tabular form. The I² test was used to assess heterogeneity across studies. A random effects model was used to estimate the pooled prevalence of undiagnosed diabetes mellitus at a 95% confidence interval (CI). Funnel plot asymmetry and Egger's tests were used to check for publication bias. The final effect size was determined by applying a trim and fill analysis in a random-effects model.

RESULTS

Our search identified 1442 studies amongst which 23 articles were eligible for inclusion in the final meta-analysis. The average pooled prevalence of undiagnosed diabetes mellitus among adults was 3.85 (95% CI: 3.10-4.60). The pooled prevalence of undiagnosed diabetes mellitus based on geographic location was 4.43 (95% CI: 3.12-5.74) in Eastern Africa; 4.72 (95% CI: 2.64-6.80) in Western Africa; 4.27 (95% CI: 1.77-6.76) in Northern Africa and 1.46 (95%CI: 0.57-2.34) in southern Africa respectively.

CONCLUSION

Our findings indicate a high prevalence of undiagnosed diabetes in Africa and suggest that it may be more prevalent in Western Africa than the rest of the regions. Given the high levels of undiagnosed diabetes in the Africa region, more attention should be paid to incorporating diabetes screening and treatment services into existing diabetes related programs to reduce the prevalence of undiagnosed cases.

Reprint of: Blood Sugar Regulation for Cardiovascular Health Promotion and Disease Prevention: JACC Health Promotion Series

The primary objective of this study was to analyze the most up-to-date evidence regarding whether and how blood sugar regulation influences cardiovascular health promotion and disease prevention by carrying out an umbrella review. Three separate, systematic literature searches identified 2,343 papers in total. Overall, 44 studies were included for data extraction and analysis. The included systematic reviews and meta-analyses published between January 1, 2016, and December 31, 2017, were of good to very good quality (median Overview Quality Assessment Questionnaire score = 17). Identified evidence suggests that cardiovascular disease (CVD) prevention services should consider regulation of blood glucose as a key target for intervention. Furthermore, the recommendations for effective intervention and service development/training described here for prevention of CVD should be adopted into evidence-based practice guidelines. Multidisciplinary teams should be formed to deliver multicomponent interventions in community-based settings. There may be substantial opportunities for integrating CVD and diabetes prevention services.

Blood Sugar Regulation for Cardiovascular Health Promotion and Disease Prevention: JACC Health Promotion Series

The primary objective of this study was to analyze the most up-to-date evidence regarding whether and how blood sugar regulation influences cardiovascular health promotion and disease prevention by carrying out an umbrella review. Three separate, systematic literature searches identified 2,343 papers in total. Overall, 44 studies were included for data extraction and analysis. The included systematic reviews and meta-analyses published between January 1, 2016, and December 31, 2017, were of good to very good quality (median Overview Quality Assessment Questionnaire score = 17). Identified evidence suggests that cardiovascular disease (CVD) prevention services should consider regulation of blood glucose as a key target for intervention. Furthermore, the recommendations for effective intervention and service development/training described here for prevention of CVD should be adopted into evidence-based practice guidelines. Multidisciplinary teams should be formed to deliver multicomponent interventions in community-based settings. There may be substantial opportunities for integrating CVD and diabetes prevention services.

The prevalence of pre-diabetes and diabetes in the Kuwaiti adult population in 2014

BACKGROUND

Kuwait ranks among the top 20 countries worldwide in diabetes prevalence. This study's objectives were to assess the prevalence of pre-diabetes and diabetes in Kuwaiti adults.

METHODS

Kuwaiti citizens aged 18-69 years (n = 3915) were studied using the WHO's STEPwise survey methodology, including its Instrument for Chronic Disease Risk Factor Surveillance. Participants' demographics, medical history, physical measurements and blood biochemistry were assessed. A subset of 2561 individuals completed all three survey steps, including fasting plasma glucose (FPG) and HbA1c assays. The study assessed the prevalence of pre-diabetes (FPG 6.1-6.9 mmol/L or HbA1c level 5.7-6.4%) and diabetes (self-reported history of diabetes with prescription of diabetes medications or FPG ≥ 7 mmol/L or HbA1c level ≥6.5%).

RESULTS

The prevalence of pre-diabetes was 19.4% [95% CI: 17.9-21.0%] (By sex: Men, 19.3%; Women, 19.5%; p = 0.92; By age (years): 18-29 y, 13.9%; 30-44 y, 22.6%; 45-59 y, 25.8%; 60-69 y, 16.4%; p < 0.001). The prevalence of diabetes was 18.8% [17.3-20.4%] (By sex: Men, 20.4%; Women, 17.4%; p = 0.055; By age: 18-29 y, 6.6%; 30-44 y, 14.0%; 45-59 y, 36.7%; 60-69 y, 62.8%; p < 0.001), of whom 41.5% were previously undiagnosed. Diabetes prevalence was 27.4% among those with body mass index (BMI) ≥ 30 kg/m², 29% among those with elevated waist-hip ratio and 36% among those with hypertension. Diabetes was positively associated with BMI, waist-hip ratio and blood pressure level. Pre-diabetes was positively associated with BMI and waist-hip ratio, but not blood pressure level.

CONCLUSIONS

Almost 40% of Kuwaiti citizens had pre-diabetes or diabetes. Urgent public health action is needed to decrease diabetes prevalence and thus avoid associated morbidity and mortality.

Systematic literature review of the health economic implications of early detection by screening populations at risk for type 2 diabetes

BACKGROUND

Undetected/uncontrolled diabetes is associated with substantial morbidity and mortality and consequent costs. Early detection through screening identifies patients at risk, allowing for earlier treatment initiation.

OBJECTIVES

To determine the economic impact of screening for type 2 diabetes (T2DM).

DATA SOURCES

We systematically reviewed health economic analyses of screening programs for T2DM/pre-diabetes.

STUDY ELIGIBILITY CRITERIA

Published between 2000 and 2015 in any language. Articles must have reported costs of screening, test/patient outcomes and cost-effectiveness.

PARTICIPANTS AND INTERVENTIONS

Any type of screening (universal, targeted, opportunistic) was accepted.

METHODS

Data were extracted from Scopus/Medline/Embase, then tabulated.

RESULTS

There were 137 studies identified, 108 rejected; 29 were analyzed. Screening types included 18 universal, 8 targeted and 8 opportunistic. One study screened for pre-diabetes, 16 for T2DM and 12 examined both. Fourteen (48%) reported costs of screening only, 9 (31%) costs of screening combined with interventions and 6 (21%) presented all costs separately. Screening was compared to no screening in 13 studies (45%); screening was cost-effective in 8 (62%), not cost-effective in 4 (31%) and neither in 1 (8%). When comparing different screening methods, 6 found targeted screening was cost-effective compared with universal screening (none found the opposite), 2 found opportunistic superior to universal. Sensitivity analyses generally confirmed primary findings. Cost drivers included prevalence of T2DM/pre-diabetes, type of blood test used and uptake of testing. For optimal cost-effectiveness, screening for both T2DM and pre-diabetes should be initiated around age 45-50, with repeated testing every 5 years.

CONCLUSIONS/IMPLICATIONS

Targeted screening appears to be cost-effective compared to universal screening.

Receipt of Glucose Testing and Performance of Two US Diabetes Screening Guidelines, 2007-2012

BACKGROUND

Screening guidelines are used to help identify prediabetes and diabetes before implementing evidence-based prevention and treatment interventions. We examined screening practices benchmarking against two US guidelines, and the capacity of each guideline to identify dysglycemia.

METHODS

Using 2007-2012 National Health and Nutrition Examination Surveys, we analyzed nationally-representative, cross-sectional data from 5,813 fasting non-pregnant adults aged ≥20 years without self-reported diabetes. We examined proportions of adults eligible for diagnostic glucose testing and those who self-reported receiving testing in the past three years, as recommended by the American Diabetes Association (ADA) and the US Preventive Services Task Force (USPSTF-2008) guidelines. For each screening guideline, we also assessed sensitivity, specificity, and positive (PPV) and negative predictive values in identifying dysglycemia (defined as fasting plasma glucose ≥100 mg/dl or hemoglobin A1c ≥5.7%).

RESULTS

In 2007-2012, 73.0% and 23.7% of US adults without diagnosed diabetes met ADA and USPSTF-2008 criteria for screening, respectively; and 91.5% had at least one major risk factor for diabetes. Of those ADA- or USPSTF-eligible adults, about 51% reported being tested within the past three years. Eligible individuals not tested were more likely to be lower educated, poorer, uninsured, or have no usual place of care compared to tested eligible adults. Among adults with ≥1 major risk factor, 45.7% reported being tested, and dysglycemia yields (i.e., PPV) ranged from 45.8% (high-risk ethnicity) to 72.6% (self-reported prediabetes). ADA criteria and having any risk factor were more sensitive than the USPSTF-2008 guideline (88.8-97.7% vs. 31.0%) but less specific (13.5-39.7% vs. 82.1%) in recommending glucose testing, resulting in lower PPVs (47.7-54.4% vs. 58.4%).

CONCLUSION

Diverging recommendations and variable performance of different guidelines may be impeding national diabetes prevention and treatment efforts. Efforts to align screening recommendations may result in earlier identification of adults at high risk for prediabetes and diabetes.

Predictors of hyperglycaemic individuals who do not follow up with physicians after screening in Japan: a cohort study

AIMS

Although people screened as being hyperglycaemic often fail to follow up with physicians for clinical assessment, epidemiologic findings on the frequency and predictors of not following up (hereafter, "no follow-up") are lacking. The purpose of this study was to examine the no follow-up rate with physicians after screening for diabetes and predictors of no follow-up.

METHODS

We assessed cases of no follow-up with physicians within six months after screening based on medical claims data from employee-based social health insurance programs in Japan, for people aged 20 to 68 years from 2005 to 2010.

RESULTS

Among 3878 screened participants with hyperglycaemia, 2527 (65%) did not follow up with their physicians within six months after screening. Multiple logistic regression analysis revealed that younger age and lower blood glucose level predicted no follow-up among both men and women, while lower body mass index and negative proteinuria also predicted no follow-up among men. Treatment for dyslipidaemia facilitated follow-up among both genders, and treatment for hypertension or depression facilitated follow-up among men.

CONCLUSIONS

Approximately two thirds of individuals screened as having hyperglycaemia did not follow up with their physicians within six months after screening. Predictors of no follow-up were younger age and milder hyperglycaemia. Being on treatment for co-morbidities tended to facilitate follow-up.

External validation of the UKPDS risk engine in incident type 2 diabetes: a need for new type 2 diabetes-specific risk equations

OBJECTIVE

To evaluate the performance of the UK Prospective Diabetes Study Risk Engine (UKPDS-RE) for predicting the 10-year risk of cardiovascular disease end points in an independent cohort of U.K. patients newly diagnosed with type 2 diabetes.

RESEARCH DESIGN AND METHODS

This was a retrospective cohort study using routine health care data collected between April 1998 and October 2011 from ∼350 U.K. primary care practices contributing to the Clinical Practice Research Datalink (CPRD). Participants comprised 79,966 patients aged between 35 and 85 years (388,269 person-years) with 4,984 cardiovascular events. Four outcomes were evaluated: first diagnosis of coronary heart disease (CHD), stroke, fatal CHD, and fatal stroke.

RESULTS

Accounting for censoring, the observed versus predicted 10-year event rates were as follows: CHD 6.1 vs. 16.5%, fatal CHD 1.9 vs. 10.1%, stroke 7.0 vs. 10.1%, and fatal stroke 1.7 vs. 1.6%, respectively. The UKPDS-RE showed moderate discrimination for all four outcomes, with the concordance index values ranging from 0.65 to 0.78.

CONCLUSIONS

The UKPDS stroke equations showed calibration ranging from poor to moderate; however, the CHD equations showed poor calibration and considerably overestimated CHD risk. There is a need for revised risk equations in type 2 diabetes.

An economic evaluation for prevention of diabetes mellitus in a developing country: a modelling study

BACKGROUND

The serious consequences of diabetes mellitus, and the subsequent economic burden, call for urgent preventative action in developing countries. This study explores the clinical and economic outcomes of strategies that could potentially prevent diabetes based on Chinese circumstances. It aims to provide indicators for the long-term allocation of healthcare resources for authorities in developing countries.

METHODS

A representative sample of Chinese adults was used to create a simulated population of 20,000 people aged 25 years and above. The hybrid decision tree Markov model was developed to compare the long-term clinical and economic outcomes of four simulated diabetes prevention strategies with a control group, where no prevention applied. These preventive strategies were the following: (i) one-off screening for undiagnosed diabetes and impaired glucose tolerance (IGT), with lifestyle interventions on diet, (ii) on exercise, (iii) on diet combined exercise (duo-intervention) respectively in those with IGT, and (iv) one-off screening alone. Independent age-specific models were simulated based on diverse incidences of diabetes, mortalities and health utilities. The reported outcomes were the following: the remaining survival years, the quality-adjusted life years (QALYs) per diabetes or IGT subjects, societal costs per simulated subject and the comparisons between preventions and control over 40 years. Sensitivity analyses were performed based on variations of all assumptions, in addition to the performance and the compliance of screening.

RESULTS

Compared with the control group, all simulated screening programmes prolonged life expectancy at the initiation ages of 25 and 40 years, postponed the onset of diabetes and increased QALYs at every initiation age. Along with an assumption of six years intervention, prevention programmes were associated with cost-saving compared with the control group, especially in the population aged 25 years. The savings were at least US$2017 per subject, but no statistically significant difference was observed among the intervention strategies within each age groups. The cost savings were reduced when screening was affected by poor performance and noncompliance.

CONCLUSIONS

Developing countries have few effective strategies to manage the prevention of diabetes. One-off screening for undiagnosed diabetes and IGT, with appropriate lifestyle interventions for those with IGT are cost saving in China, especially in young adults.

Screening for diabetes mellitus using gingival crevicular blood with the help of a self-monitoring device

Purpose

The purpose of study was to compare blood glucose in capillary finger-prick blood and gingival crevice blood using a self-monitoring blood glucose device among patients with gingivitis or periodontitis.

Methods

Thirty patients with gingivitis or periodontitis and bleeding on probing (BOP) were chosen. The following clinical periodontal parameters were noted: probing depth, BOP, gingival bleeding index, and periodontal disease index. Blood samples were collected from gingival crevicular blood (GCB) and capillary finger-prick blood (CFB). These samples were analyzed using a glucose self-monitoring device.

Results

Descriptive statistical analysis has been carried out in the present study. Data were analyzed using a Pearson's correlation coefficient and Student's t-test. A r-value of 0.97 shows very strong correlation between CFB and GCB, which was statistically highly significant (P<0.0001).

Conclusions

The authors conclude that GCB may serve as potential source of screening blood glucose during routine periodontal examination in populations with an unknown history of diabetes mellitus.

Risk scores based on self-reported or available clinical data to detect undiagnosed type 2 diabetes: a systematic review

OBJECTIVE

To systematically review published primary research on the development or validation of risk scores that require only self-reported or available clinical data to identify undiagnosed Type 2 Diabetes Mellitus (T2DM).

METHODS

A systematic literature search of Medline and EMBASE was conducted until January 2011. Studies focusing on the development or validation of risk scores to identify undiagnosed T2DM were included. Risk scores to predict future risk of T2DM were excluded.

RESULTS

Thirty-one studies were included; 17 developed a new risk score, 14 validated existing scores. Twenty-six studies were conducted in high-income countries. Age and measures of body mass/fat distribution were the most commonly used predictor variables. Studies developing new scores performed better than validation studies, with 11 reporting an AUC of >0.80 compared to one validation study. Fourteen validation studies reported sensitivities of <80%. The performance of scores did not differ by the number of variables included or the country setting.

CONCLUSIONS

There is a proliferation of newly developed risk scores using similar variables, which sometimes perform poorly upon external validation. Future research should explore the recalibration, validation and applicability of existing scores to other settings, particularly in low/middle income countries, and on the utility of scores to improve diabetes-related outcomes.

The cost of diagnosing Type 2 diabetes mellitus by clinical opportunistic screening in general practice

AIMS

Type 2 diabetes is associated with serious complications and shortens life. Its prevalence is increasing rapidly worldwide and no cure is available. One logical response is to diagnose the condition as early as possible. Clinical opportunistic screening is one mechanism for making the diagnosis before symptoms are reported. This paper reports the cost of using this technique in UK general practice.

METHODS

In one UK general practice, the electronic medical records were searched to determine the number of blood glucose and oral glucose tolerance tests undertaken for non-pregnant adults without known diabetes over three consecutive years. The laboratory, staff and administrative costs associated with these screening tests were calculated. The records of all patients newly diagnosed with Type 2 diabetes during the same period were reviewed to identify diagnoses made by clinical opportunistic screening. Total costs were divided by the number of diagnoses to determine a cost per diagnosis detected by opportunistic screening.

RESULTS

During the study period, 5720 screening tests were conducted for 2763 patients. Over the 3 years, 86 patients were diagnosed with Type 2 diabetes, 54 (63%) via screening (yield 2.0%; number needed to screen 51.2). The screening costs totalled £ 20,372. The average cost per new screen-detected diagnosis was £ 377.

CONCLUSIONS

Almost two-thirds of new cases of Type 2 diabetes can be detected before symptoms are reported, at reasonable cost by opportunistic screening in general practice, without the use of extra resources. As an affordable alternative to population screening, clinical opportunistic screening merits further consideration.

Cardiovascular risk reduction following diagnosis of diabetes by screening: 1-year results from the ADDITION-Cambridge trial cohort

BACKGROUND

Uncertainties persist concerning the effects of early intensive management of type 2 diabetes and which patients benefit most from such an approach.

AIM

To describe change in modelled cardiovascular risk in the 14 months following diagnosis, and to examine which baseline patient characteristics and treatment components are associated with risk reduction.

DESIGN AND SETTING

A cohort of individuals from a pragmatic, single-blind, cluster-randomised controlled trial of 236 females and 361 males with screen-detected type 2 diabetes and without prior cardiovascular disease (CVD), from 49 GP surgeries in eastern England, examined at baseline (2002-2006) and after 14-months' follow-up.

METHOD

Multiple linear regression was used to quantify the association between baseline patient characteristics, treatment components, and change in modelled 10-year cardiovascular risk (UK Prospective Diabetes Study [UKPDS] [version 3] risk engine).

RESULTS

There was a downward shift in the distribution of modelled CVD risk over 14 months mean 31% (standard deviation [SD] = 14%) to 26% [SD = 13%]). Older individuals, males, and those with a larger waist circumference at baseline exhibited smaller risk reductions. Individuals prescribed higher numbers of drugs over the follow-up period, and those who decreased their energy intake or reduced their weight, demonstrated larger reductions in modelled risk.

CONCLUSION

It is possible to achieve significant reductions in modelled CVD risk over 14 months following diagnosis of diabetes by screening. Risk reduction appeared to be driven mainly by prescription of higher numbers of drugs, decreased energy intake, and weight reduction. There was room for further risk reduction, as many patients were not prescribed recommended treatments.

Screening for type 2 diabetes. Lessons from the ADDITION-Europe study

AIMS

To describe and compare attendance rates and the proportions of people identified with Type 2 diabetes mellitus in people with previously unknown diabetes who participated in screening programmes undertaken in general practice in the UK, Denmark and the Netherlands as part of the ADDITION-Europe study.

METHODS

In Cambridge, routine computer data searches were conducted to identify individuals aged 40-69 years at high risk of Type 2 diabetes using the Cambridge Diabetes Risk Score. In Denmark, the Danish Diabetes Risk Score was mailed to individuals aged 40-69 years, or completed by patients visiting their general practitice. In the Netherlands, the Hoorn Symptom Risk Questionnaire was mailed to individuals aged 50-69 years. In these three centres, high-risk individuals were invited to attend subsequent steps in the screening programme, including random blood glucose, HbA(1c) , fasting blood glucose and/or oral glucose tolerance test. In Leicester, eligible people aged 40-69 years were invited directly for an oral glucose tolerance test. In all centres, Type 2 diabetes was defined according to World Health Organization 1999 diagnostic criteria.

RESULTS

Attendance rates ranged from 20.2% (oral glucose tolerance test in Leicester without pre-stratification) to 95.1% (random blood glucose in opportunistic screening in Denmark in high-risk people). The percentage of people with newly detected Type 2 diabetes from the target population ranged from 0.33% (Leicester) to 1.09% (the Netherlands).

CONCLUSIONS

Screening for Type 2 diabetes was acceptable and feasible, but relatively few participants were diagnosed in all participating centres. Different strategies may be required to increase initial attendance and ensure completion of screening programmes.

Prevalence of neuropathy and peripheral arterial disease and the impact of treatment in people with screen-detected type 2 diabetes: the ADDITION-Denmark study

OBJECTIVE

There is limited evidence on how intensive multifactorial treatment (IT) improves outcomes of diabetes when initiated in the lead time between detection by screening and diagnosis in routine clinical practice. We examined the effects of early detection and IT of type 2 diabetes in primary care on the prevalence of diabetic peripheral neuropathy (DPN) and peripheral arterial disease (PAD) 6 years later in a pragmatic, cluster-randomized parallel group trial.

RESEARCH DESIGN AND METHODS

A stepwise screening program in 190 general practices in Denmark was used to identify 1,533 people with type 2 diabetes. General practices were randomized to deliver either IT or routine care (RC) as recommended through national guidelines. Participants were followed for 6 years and measures of DPN and PAD were applied.

RESULTS

We found no statistically significant effect of IT on the prevalence of DPN and PAD compared with RC. The prevalence of an ankle brachial index ≤0.9 was 9.1% (95% CI 6.0-12.2) in the RC arm and 7.3% (5.0-9.6) in the IT arm. In participants tested for vibration detection threshold and light touch sensation, the prevalence of a least one abnormal test was 34.8% (26.7-43.0) in the RC arm and 30.1% (24.1-36.1) in the IT arm.

CONCLUSIONS

In a population with screen-detected type 2 diabetes, we did not find that screening followed by IT led to a statistically significant difference in the prevalence of DPN and PAD 6 years after diagnosis. However, treatment levels were high in both groups.

Effect of early intensive multifactorial therapy on 5-year cardiovascular outcomes in individuals with type 2 diabetes detected by screening (ADDITION-Europe): a cluster-randomised trial

BACKGROUND

Intensive treatment of multiple cardiovascular risk factors can halve mortality among people with established type 2 diabetes. We investigated the effect of early multifactorial treatment after diagnosis by screening.

METHODS

In a pragmatic, cluster-randomised, parallel-group trial done in Denmark, the Netherlands, and the UK, 343 general practices were randomly assigned screening of registered patients aged 40-69 years without known diabetes followed by routine care of diabetes or screening followed by intensive treatment of multiple risk factors. The primary endpoint was first cardiovascular event, including cardiovascular mortality and morbidity, revascularisation, and non-traumatic amputation within 5 years. Patients and staff assessing outcomes were unaware of the practice's study group assignment. Analysis was done by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00237549.

FINDINGS

Primary endpoint data were available for 3055 (99·9%) of 3057 screen-detected patients. The mean age was 60·3 (SD 6·9) years and the mean duration of follow-up was 5·3 (SD 1·6) years. Improvements in cardiovascular risk factors (HbA(1c) and cholesterol concentrations and blood pressure) were slightly but significantly better in the intensive treatment group. The incidence of first cardiovascular event was 7·2% (13·5 per 1000 person-years) in the intensive treatment group and 8·5% (15·9 per 1000 person-years) in the routine care group (hazard ratio 0·83, 95% CI 0·65-1·05), and of all-cause mortality 6·2% (11·6 per 1000 person-years) and 6·7% (12·5 per 1000 person-years; 0·91, 0·69-1·21), respectively.

INTERPRETATION

An intervention to promote early intensive management of patients with type 2 diabetes was associated with a small, non-significant reduction in the incidence of cardiovascular events and death.

FUNDING

National Health Service Denmark, Danish Council for Strategic Research, Danish Research Foundation for General Practice, Danish Centre for Evaluation and Health Technology Assessment, Danish National Board of Health, Danish Medical Research Council, Aarhus University Research Foundation, Wellcome Trust, UK Medical Research Council, UK NIHR Health Technology Assessment Programme, UK National Health Service R&D, UK National Institute for Health Research, Julius Center for Health Sciences and Primary Care, University Medical Center, Utrecht, Novo Nordisk, Astra, Pfizer, GlaxoSmithKline, Servier, HemoCue, Merck.

HbA1c and cardiovascular risk score identify people who may benefit from preventive interventions: a 7 year follow-up of a high-risk screening programme for diabetes in primary care (ADDITION), Denmark

AIMS/HYPOTHESIS

The measurement of HbA(1c) is suggested as a diagnostic test for diabetes. Screening for diabetes also identifies individuals with elevated cardiovascular risk but who are free of diabetes. This study aims to assess whether screening by HbA(1c) or glucose measures alone, or in combination with a cardiovascular risk assessment, identifies people who may benefit from preventive interventions, i.e. people with screen detected diabetes and people belonging to groups with excess mortality, during a median follow-up of 7 years.

METHODS

A population-based, stepwise high-risk screening programme was performed in 193 family practices from 2001 to 2006. Individuals aged between 40 and 69 years (N = 163,185) were sent a diabetes risk questionnaire. Of these, 20,916 people at risk of diabetes were stratified by glucose measures (normal glucose tolerance [NGT], impaired fasting glucose [IFG], impaired glucose tolerance [IGT] and diabetes), HbA(1c) (<6%; 6.0-6.4%; or ≥ 6.5%) and cardiovascular risk (heart SCORE <5 or ≥ 5). People were followed for a median of 7 years or until death. Excess mortality was calculated using the Cox hazard ratio (HR).

RESULTS

SCORE ≥ 5 identified 91.7% (95% CI 91.1-92.3%) of those who might benefit from preventive interventions. SCORE ≥ 5 in combination with HbA(1c) ≥ 6.0% identified 96.7% (95% CI 96.3-97.0%), compared with 97.6% (95%CI 97.2-97.9%) in combination with glucose measures. Glucose measures or HbA(1c) alone identified 26.1% (95% CI 25.2-27.0%) and 19.8% (95% CI 19.0-20.6%), respectively.

CONCLUSION/INTERPRETATION

In a population-based high risk screening programme in primary care, HbA(1c) ≥ 6.0% combined with an elevated cardiovascular risk assessment (SCORE ≥ 5) can feasibly be used to identify those who may benefit from preventive lifestyle intervention and/or polypharmacy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT 00237549.

FUNDING

The study received unrestricted grants from Novo Nordisk, Novo Nordisk Scandinavia, Astra Denmark, Pfizer Denmark, GlaxoSmithKline Pharma Denmark, Servier Denmark and HemoCue Denmark.

Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus

BACKGROUND

Multiple laboratory tests are used to diagnose and manage patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these tests varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for the use of laboratory testing for patients with diabetes. A new system was developed to grade the overall quality of the evidence and the strength of the recommendations. Draft guidelines were posted on the Internet and presented at the 2007 Arnold O. Beckman Conference. The document was modified in response to oral and written comments, and a revised draft was posted in 2010 and again modified in response to written comments. The National Academy of Clinical Biochemistry and the Evidence-Based Laboratory Medicine Committee of the American Association for Clinical Chemistry jointly reviewed the guidelines, which were accepted after revisions by the Professional Practice Committee and subsequently approved by the Executive Committee of the American Diabetes Association.

CONTENT

In addition to long-standing criteria based on measurement of plasma glucose, diabetes can be diagnosed by demonstrating increased blood hemoglobin A(1c) (HbA(1c)) concentrations. Monitoring of glycemic control is performed by self-monitoring of plasma or blood glucose with meters and by laboratory analysis of HbA(1c). The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of autoantibodies, urine albumin, insulin, proinsulin, C-peptide, and other analytes are addressed.

SUMMARY

The guidelines provide specific recommendations that are based on published data or derived from expert consensus. Several analytes have minimal clinical value at present, and their measurement is not recommended.

Screening for type 2 diabetes and dysglycemia

Type 2 diabetes mellitus (T2DM) and dysglycemia (impaired glucose tolerance and/or impaired fasting glucose) are increasingly contributing to the global burden of diseases. The authors reviewed the published literature to critically evaluate the evidence on screening for both conditions and to identify the gaps in current understanding. Acceptable, relatively simple, and accurate tools can be used to screen for both T2DM and dysglycemia. Lifestyle modification and/or medication (e.g., metformin) are cost-effective in reducing the incidence of T2DM. However, their application is not yet routine practice. It is unclear whether diabetes-prevention strategies, which influence cardiovascular risk favorably, will also prevent diabetic vascular complications. Cardioprotective therapies, which are cost-effective in preventing complications in conventionally diagnosed T2DM, can be used in screen-detected diabetes, but the magnitude of their effects is unknown. Economic modeling suggests that screening for both T2DM and dysglycemia may be cost-effective, although empirical data on tangible benefits in preventing complications or death are lacking. Screening for T2DM is psychologically unharmful, but the specific impact of attributing the label of dysglycemia remains uncertain. Addressing these gaps will inform the development of a screening policy for T2DM and dysglycemia within a holistic diabetes prevention and control framework combining secondary and high-risk primary prevention strategies.

Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus

BACKGROUND

Multiple laboratory tests are used to diagnose and manage patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these tests varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for the use of laboratory testing for patients with diabetes. A new system was developed to grade the overall quality of the evidence and the strength of the recommendations. Draft guidelines were posted on the Internet and presented at the 2007 Arnold O. Beckman Conference. The document was modified in response to oral and written comments, and a revised draft was posted in 2010 and again modified in response to written comments. The National Academy of Clinical Biochemistry and the Evidence Based Laboratory Medicine Committee of the AACC jointly reviewed the guidelines, which were accepted after revisions by the Professional Practice Committee and subsequently approved by the Executive Committee of the American Diabetes Association.

CONTENT

In addition to long-standing criteria based on measurement of plasma glucose, diabetes can be diagnosed by demonstrating increased blood hemoglobin A(1c) (Hb A(1c)) concentrations. Monitoring of glycemic control is performed by self-monitoring of plasma or blood glucose with meters and by laboratory analysis of Hb A(1c). The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of autoantibodies, urine albumin, insulin, proinsulin, C-peptide, and other analytes are addressed.

SUMMARY

The guidelines provide specific recommendations that are based on published data or derived from expert consensus. Several analytes have minimal clinical value at present, and their measurement is not recommended.

Comparison of different stepwise screening strategies for type 2 diabetes: Finding from Danish general practice, Addition-DK

AIM

To examine attendance, number of people with T2DM and costs of three different stepwise screening strategies for T2DM in general practice (GP).

METHODS

Diabetes risk questionnaires were mailed to individuals aged 40-69 years from 45 general practices in 2001-2002 and individuals at high risk for T2DM, were asked to contact their GP to arrange a screening test. In 2005-2006, 26 general practices were randomised into two different opportunistic screening programmes (OP-direct and OP-subsequent) and risk questionnaires were distributed to individuals aged 40-69 years during GP consultations. In the OP-direct approach, high-risk individuals were offered to start the screening during the actual consultation while high-risk individuals in the OP-subsequent approach, were invited to a screening test at a later date. We report attendance, number of people with T2DM and costs of each screening approach.

RESULTS

The mail-distributed approach identified 0.8% of the target population with T2DM, the OP-direct approach and the OP-subsequent approach, 0.9% and 0.5% respectively. Cost per person with T2DM was in the mail-distributed approach: € 1058, OP-direct approach: € 707 and the OP-subsequent approach: € 727.

CONCLUSION

This study indicates that opportunistic screening identifies the same level of unknown diabetes as a mail-distributed approach but with lower costs.

Screening for type 2 diabetes: an update of the evidence

A growing body of evidence on diabetes screening has been published during the last 10 years. Type 2 diabetes meets many but not all of the criteria for screening. Concerns about potential harms of screening have largely been resolved. Screening identifies a high-risk population with the potential to gain from widely available interventions. However, in spite of the findings of modelling studies, the size of the benefit of earlier initiation of treatment and the overall cost-effectiveness remains uncertain, in contrast to other screening programmes (such as for abdominal aortic aneurysms) that are yet to be fully implemented. There is also uncertainty about optimal specifications and implementation of a screening programme, and further work to complete concerning development and delivery of individual- and population-level preventive strategies. While there is growing evidence of the net benefit of earlier detection of individuals with prevalent but undiagnosed diabetes, there remains limited justification for a policy of universal population-based screening for type 2 diabetes at the present time. Data from ongoing studies should inform the key assumptions in existing modelling studies and further reduce uncertainty.

Who attends a UK diabetes screening programme? Findings from the ADDITION-Cambridge study

AIMS

One of the factors influencing the cost-effectiveness of population screening for Type 2 diabetes may be uptake. We examined attendance and practice- and individual-level factors influencing uptake at each stage of a diabetes screening programme in general practice.

METHODS

A stepwise screening programme was undertaken among 135, 825 people aged 40-69 years without known diabetes in 49 general practices in East England. The programme included a score based on routinely available data (age, sex, body mass index and prescribed medication) to identify those at high risk, who were offered random capillary blood glucose (RBG) and glycosylated haemoglobin tests. Those screening positive were offered fasting capillary blood glucose (FBG) and confirmatory oral glucose tolerance tests (OGTT).

RESULTS

There were 33 539 high-risk individuals invited for a RBG screening test; 24 654 (74%) attended. Ninety-four per cent attended the follow-up FBG test and 82% the diagnostic OGTT. Seventy per cent of individuals completed the screening programme. Practices with higher general practitioner staff complements and those located in more deprived areas had lower uptake for RBG and FBG tests. Male sex and a higher body mass index were associated with lower attendance for RBG testing. Older age, prescription of antihypertensive medication and a higher risk score were associated with higher attendance for FBG and RBG tests.

CONCLUSIONS

High attendance rates can be achieved by targeted stepwise screening of individuals assessed as high risk by data routinely available in general practice. Different strategies may be required to increase initial attendance, ensure completion of the screening programme, and reduce the risk that screening increases health inequalities.

Age at initiation and frequency of screening to detect type 2 diabetes: a cost-effectiveness analysis

BACKGROUND

No clinical trials have assessed the effects or cost-effectiveness of sequential screening strategies to detect new cases of type 2 diabetes. We used a mathematical model to estimate the cost-effectiveness of several screening strategies.

METHODS

We used person-specific data from a representative sample of the US population to create a simulated population of 325,000 people aged 30 years without diabetes. We used the Archimedes model to compare eight simulated screening strategies for type 2 diabetes with a no-screening control strategy. Strategies differed in terms of age at initiation and frequency of screening. Once diagnosed, diabetes treatment was simulated in a standard manner. We calculated the effects of each strategy on the incidence of type 2 diabetes, myocardial infarction, stroke, and microvascular complications in addition to quality of life, costs, and cost per quality-adjusted life-year (QALY).

FINDINGS

Compared with no screening, all simulated screening strategies reduced the incidence of myocardial infarction (3-9 events prevented per 1000 people screened) and diabetes-related microvascular complications (3-9 events prevented per 1000 people), and increased the number of QALYs (93-194 undiscounted QALYs) added over 50 years. Most strategies prevented a significant number of simulated deaths (2-5 events per 1000 people). There was little or no effect of screening on incidence of stroke (0-1 event prevented per 1000 people). Five screening strategies had costs per QALY of about US$10,500 or less, whereas costs were much higher for screening started at 45 years of age and repeated every year ($15,509), screening started at 60 years of age and repeated every 3 years ($25,738), or a maximum screening strategy (screening started at 30 years of age and repeated every 6 months; $40,778). Several strategies differed substantially in the number of QALYs gained. Costs per QALY were sensitive to the disutility assigned to the state of having diabetes diagnosed with or without symptoms.

INTERPRETATION

In the US population, screening for type 2 diabetes is cost effective when started between the ages of 30 years and 45 years, with screening repeated every 3-5 years.

FUNDING

Novo Nordisk, Bayer HealthCare, [corrected] and Pfizer.

Rationale and design of the ADDITION-Leicester study, a systematic screening programme and randomised controlled trial of multi-factorial cardiovascular risk intervention in people with type 2 diabetes mellitus detected by screening

Background

Earlier diagnosis followed by multi-factorial cardiovascular risk intervention may improve outcomes in Type 2 Diabetes Mellitus (T2DM). Latent phase identification through screening requires structured, appropriately targeted population-based approaches. Providers responsible for implementing screening policy await evidence of clinical and cost effectiveness from randomised intervention trials in screen-detected T2DM cases. UK South Asians are at particularly high risk of abnormal glucose tolerance and T2DM. To be effective national screening programmes must achieve good coverage across the population by identifying barriers to the detection of disease and adapting to the delivery of earlier care. Here we describe the rationale and methods of a systematic community screening programme and randomised controlled trial of cardiovascular risk management within a UK multiethnic setting (ADDITION-Leicester).

Design

A single-blind cluster randomised, parallel group trial among people with screen-detected T2DM comparing a protocol driven intensive multi-factorial treatment with conventional care.

Methods

ADDITION-Leicester consists of community-based screening and intervention phases within 20 general practices coordinated from a single academic research centre. Screening adopts a universal diagnostic approach via repeated 75g-Oral Glucose Tolerance Tests within an eligible non-diabetic population of 66,320 individuals aged 40-75 years (25-75 years South Asian). Volunteers also provide detailed medical and family histories; complete health questionnaires, undergo anthropometric measures, lipid profiling and a proteinuria assessment. Primary outcome is reduction in modelled Coronary Heart Disease (UKPDS CHD) risk at five years. Seven thousand (30% of South Asian ethnic origin) volunteers over three years will be recruited to identify a screen-detected T2DM cohort (n = 285) powered to detected a 6% relative difference (80% power, alpha 0.05) between treatment groups at one year. Randomisation will occur at practice-level with newly diagnosed T2DM cases receiving either conventional (according to current national guidelines) or intensive (algorithmic target-driven multi-factorial cardiovascular risk intervention) treatments.

Discussion

ADDITION-Leicester is the largest multiethnic (targeting >30% South Asian recruitment) community T2DM and vascular risk screening programme in the UK. By assessing feasibility and efficacy of T2DM screening, it will inform national disease prevention policy and contribute significantly to our understanding of the health care needs of UK South Asians.

Trial registration

Clinicaltrial.gov (NCT00318032).

Cost effectiveness of preventive screening programmes for type 2 diabetes mellitus in Germany

BACKGROUND

As in several other industrialized countries, Germany's statutory health insurance (SHI) is facing rising healthcare costs as well as the challenges caused by a double-aging society. The early detection and prevention of chronic diseases is considered a possible way to reduce the impact of these developments. However, controversy surrounds the costs and effects in terms of medical and financial outcomes of such programmes.

OBJECTIVE

To examine the cost effectiveness of screening for type 2 diabetes mellitus (T2DM) from the perspective of the German SHI. The screening programme was compared with the current status quo (i.e. diagnosis of T2DM in routine clinical care or after the occurrence of the first clinical symptoms). Prevention strategies after diagnosis of pre-diabetes encompassed lifestyle and metformin interventions.

METHODS

Effects of introducing screening for T2DM were assessed based on a Markov Monte Carlo microsimulation model. In contrast to a cohort model, this approach easily allows for detailed subgroup analysis accounting for the different characteristics of the general German population that would be targeted by the screening programme. Assessed endpoints included quality of life, lifetime costs, age at diabetes diagnosis, and incidence and age at occurrence of diabetes-related complications such as myocardial infarction, stroke, renal failure and blindness.

RESULTS

Screening for T2DM was cost effective in the general population by all commonly applied standards (euro562.54 per QALY for lifestyle intervention, euro325.44 per QALY for prevention with metformin [year 2006 values]) and even cost saving in the subgroup diagnosed with pre-diabetes and treated preventively. Occurrence of diabetes-related adverse events was reduced significantly and life expectancy was increased compared with no screening.

CONCLUSIONS

These results suggest that early detection and disease prevention may be cost effective in the long term. However, additional political measures are necessary to support implementation, as the German SHI is currently lacking the necessary long-term incentives to support preventive screening programmes.

The ADDITION-Cambridge trial protocol: a cluster -- randomised controlled trial of screening for type 2 diabetes and intensive treatment for screen-detected patients

BACKGROUND

The increasing prevalence of type 2 diabetes poses a major public health challenge. Population-based screening and early treatment for type 2 diabetes could reduce this growing burden. However, the benefits of such a strategy remain uncertain.

METHODS AND DESIGN

The ADDITION-Cambridge study aims to evaluate the effectiveness and cost-effectiveness of (i) a stepwise screening strategy for type 2 diabetes; and (ii) intensive multifactorial treatment for people with screen-detected diabetes in primary care. 63 practices in the East Anglia region participated. Three undertook the pilot study, 33 were allocated to three groups: no screening (control), screening followed by intensive treatment (IT) and screening plus routine care (RC) in an unbalanced (1:3:3) randomisation. The remaining 27 practices were randomly allocated to IT and RC. A risk score incorporating routine practice data was used to identify people aged 40-69 years at high-risk of undiagnosed diabetes. In the screening practices, high-risk individuals were invited to take part in a stepwise screening programme. In the IT group, diabetes treatment is optimised through guidelines, target-led multifactorial treatment, audit, feedback, and academic detailing for practice teams, alongside provision of educational materials for newly diagnosed participants. Primary endpoints are modelled cardiovascular risk at one year, and cardiovascular mortality and morbidity at five years after diagnosis of diabetes. Secondary endpoints include all-cause mortality, development of renal and visual impairment, peripheral neuropathy, health service costs, self-reported quality of life, functional status and health utility. Impact of the screening programme at the population level is also assessed through measures of mortality, cardiovascular morbidity, health status and health service use among high-risk individuals.

DISCUSSION

ADDITION-Cambridge is conducted in a defined high-risk group accessible through primary care. It addresses the feasibility of population-based screening for diabetes, as well as the benefits and costs of screening and intensive multifactorial treatment early in the disease trajectory. The intensive treatment algorithm is based on evidence from studies including individuals with clinically diagnosed diabetes and the education materials are informed by psychological theory. ADDITION-Cambridge will provide timely evidence concerning the benefits of early intensive treatment and will inform policy decisions concerning screening for type 2 diabetes.

TRIAL REGISTRATION

Current Controlled trials ISRCTN86769081.

Impact of an informed choice invitation on uptake of screening for diabetes in primary care (DICISION): trial protocol

Background

Screening invitations have traditionally been brief, providing information only about population benefits. Presenting information about the limited individual benefits and potential harms of screening to inform choice may reduce attendance, particularly in the more socially deprived. At the same time, amongst those who attend, it might increase motivation to change behavior to reduce risks. This trial assesses the impact on attendance and motivation to change behavior of an invitation that facilitates informed choices about participating in diabetes screening in general practice. Three hypotheses are tested:

1. Attendance at screening for diabetes is lower following an informed choice compared with a standard invitation.

2. There is an interaction between the type of invitation and social deprivation: attendance following an informed choice compared with a standard invitation is lower in those who are more rather than less socially deprived.

3. Amongst those who attend for screening, intentions to change behavior to reduce risks of complications in those subsequently diagnosed with diabetes are stronger following an informed choice invitation compared with a standard invitation.

Method/Design

1500 people aged 40–69 years without known diabetes but at high risk are identified from four general practice registers in the east of England. 1200 participants are randomized by households to receive one of two invitations to attend for diabetes screening at their general practices. The intervention invitation is designed to facilitate informed choices, and comprises detailed information and a decision aid. A comparison invitation is based on those currently in use. Screening involves a finger-prick blood glucose test. The primary outcome is attendance for diabetes screening. The secondary outcome is intention to change health related behaviors in those attenders diagnosed with diabetes. A sample size of 1200 ensures 90% power to detect a 10% difference in attendance between arms, and in an estimated 780 attenders, 80% power to detect a 0.2 sd difference in intention between arms.

Discussion

The DICISION trial is a rigorous pragmatic denominator based clinical trial of an informed choice invitation to diabetes screening, which addresses some key limitations of previous trials.

Trial registration

Current Controlled Trials ISRCTN73125647

How much might cardiovascular disease risk be reduced by intensive therapy in people with screen-detected diabetes?

AIMS

To assess the cardiovascular disease (CVD) risk of people with screen-detected Type 2 diabetes and to estimate the risk reduction achievable through early intensive pharmacological intervention.

METHODS

In ADDITION-Cambridge, diabetic patients were identified among people aged 40-69 years through a stepwise screening procedure including a risk score, random and fasting capillary blood glucose, HbA(1c) and oral glucose tolerance test. In those without prior macrovascular disease, 10-year CVD risk was computed using UK Prospective Diabetes Study (UKPDS) and Framingham engines. The absolute risk reduction achievable and its plausible range were predicted using relative risk reductions for individual therapies from published trials and sensitivity analysis.

RESULTS

Of the 867 individuals with undiagnosed diabetes, 19% had pre-existing CVD, 97% were overweight or obese, 86% had hypertension, 75% had dyslipidaemia, 20% had microalbuminuria and 18% were smokers. Of those with hypertension, 35% were not prescribed drugs and 42% were suboptimally treated. Of participants with dyslipidaemia, 68% were not prescribed medications and 22% were poorly controlled. Median 10-year CVD risk was 34.0%[interquartile range (IQR) 26.2-44.6] in men and 21.5% (IQR 15.7-28.7) in women using the UKPDS engine; 38.6% (IQR 27.8-53.0) in men and 24.6% (IQR 17.2-32.9) in women using Framingham equations. In the most conservative scenario (no additive effect of therapies), the absolute risk reduction achievable through multifactorial therapy ranged from 4.9 to 9.5% (UKPDS) and from 5.4 to 10.5% (Framingham). The corresponding ranges of numbers needed to treat were 11-20 and 10-19.

CONCLUSIONS

People with screen-detected diabetes have an adverse cardiovascular risk profile, which is potentially modifiable through application of existing treatment recommendations.

Ethnic difference in inter-East Asian subjects with normal glucose tolerance and impaired glucose regulation: a systematic review and meta-analysis focusing on fasting serum insulin

AIMS

To investigate ethnic difference by focusing on fasting serum insulin (FSI) in inter-East Asian subjects with normal glucose tolerance (NGT) and impaired glucose regulation (IGR).

METHODS

Data sources included MEDLINE and EMBASE between 2001 and 2007. We conducted a search for articles containing mean or geometric mean values of FSI in East Asian subjects with NGT, IGR, or type 2 diabetes (T2DM). The Monte Carlo method was used for simulation of the mean and standard deviation of individual measures in each ethnic group; calculation of the median ratio and 95% confidence interval of individual measures between ethnic groups.

RESULTS

Twenty-two articles fully met our pre-determined criteria and were included in the meta-analysis. Results of the meta-analysis revealed that FSI level is significantly lower in Japanese subjects with NGT, IGR, or T2DM than in Korean and Chinese subjects.

CONCLUSIONS

Ethnic difference in FSI level between East Asians was observed in not only T2DM patients but also subjects with NGT or IGR. The lower FSI level in Japanese subjects was accompanied by lower triglyceride level. These results suggest that ethnic difference in dietary habit was one of the most influential factors for the ethnic difference in FSI.

Screening for type 2 diabetes is feasible, acceptable, but associated with increased short-term anxiety: a randomised controlled trial in British general practice

Background

To assess the feasibility and uptake of a diabetes screening programme; to examine the effects of invitation to diabetes screening on anxiety, self-rated health and illness perceptions.

Methods

Randomised controlled trial in two general practices in Cambridgeshire. Individuals aged 40–69 without known diabetes were identified as being at high risk of having undiagnosed type 2 diabetes using patient records and a validated risk score (n = 1,280). 355 individuals were randomised in a 2 to 1 ratio into non-invited (n = 238) and invited (n = 116) groups. A stepwise screening programme confirmed the presence or absence of diabetes. Six weeks after the last contact (either test or invitation), a questionnaire was sent to all participants, including non-attenders and those who were not originally invited. Outcome measures included attendance, anxiety (short-form Spielberger State Anxiety Inventory-STAI), self-rated health and diabetes illness perceptions.

Results

95 people (82% of those invited) attended for the initial capillary blood test. Six individuals were diagnosed with diabetes. Invited participants were more anxious than those not invited (37.6 vs. 34.1 STAI, p-value = 0.015), and those diagnosed with diabetes were considerably more anxious than those classified free of diabetes (46.7 vs. 37.0 STAI, p-value = 0.031). Non-attenders had a higher mean treatment control sub-scale (3.87 vs. 3.56, p-value = 0.016) and a lower mean emotional representation sub-scale (1.81 vs. 2.68, p-value = 0.001) than attenders. No differences in the other five illness perception sub-scales or self-rated health were found.

Conclusion

Screening for type 2 diabetes in primary care is feasible but may be associated with higher levels of short-term anxiety among invited compared with non-invited participants.

Trial registration

ISRCTN99175498

Closing the gap: using prevalence models for long-term conditions in the United Kingdom

Until now, most healthcare policies have been focused on the relatively small number of patients with long-term conditions who suffer from a high disease burden, and less attention has been directed toward detecting patients with undiagnosed long-term conditions. In the United Kingdom, population-based data on the prevalence of disease detected in primary care are now available. Prevalence models for diabetes, coronary heart disease, hypertension, and chronic obstructive pulmonary disease provide survey-based estimates for small populations based on local data on known risk factors. These suggest that a significant proportion of prevalent disease remains undiagnosed. Other models are being developed. More systematic case finding to close disease prevalence gaps may be cost-effective, but case-finding strategies need to be tested and current and new models require validation.

Ethnic difference in patients with type 2 diabetes mellitus in inter-East Asian populations: a systematic review and meta-analysis focusing on fasting serum insulin

AIMS

To investigate ethnic difference by focusing on fasting serum insulin (FSI) in inter-East Asian patients with type 2 diabetes.

METHODS

Data sources included MEDLINE and EMBASE between 2001 and 2006. We conducted a search for articles containing mean or geometric mean values of FSI in East Asian patients with type 2 diabetes. The Monte Carlo method was used for simulation of the mean and standard deviation of individual measures in each ethnic group; calculation of the median ratio and 95% confidence interval of individual measures between ethnic groups.

RESULTS

The initial search identified a total of 996 journal articles. After reviewing the titles and abstracts of these articles, 201 studies were selected for further screening and the complete papers on these studies were then reviewed in detail. Of these, seven articles fully met our pre-determined criteria and were included in the meta-analysis. Results of the meta-analysis revealed that FSI level is significantly lower in Japanese patients than in Korean and Chinese patients.

CONCLUSIONS

Results from our review of ethnic differences in dietary habit in the inter-East Asian population suggested that difference in dietary component was one of the most influential factors for the ethnic difference.

UKPDS-modelling of cardiovascular risk assessment and lifetime simulation of outcomes

Although known principally as a clinical trial, the UK Prospective Diabetes Study (UKPDS) provided longitudinal data which helped define the natural history of cardiovascular complications in Type 2 diabetes. Using clinical, epidemiological, statistical and economics methods, UKPDS investigators developed mathematical models that helped define predictors (risk factors) for cardiovascular disease including angina, myocardial infarction, stroke, peripheral vascular disease and death in Type 2 diabetes. The UKPDS made clearer the contributions to risk of age, hyperglycaemia, elevated blood pressure, adverse blood lipids and smoking. Equations were developed, combined and incorporated into the UKPDS Risk Engine and the UKPDS Outcomes models. For example, the UKPDS risk engine-version 2-estimates that a white 62-year-old man with 11 years of Type 2 diabetes, a glycated haemoglobin of 8.3%, a systolic blood pressure of 145 mmHg and total and high-density lipoprotein cholesterol values of 5.8 and 1.1 mmol/l who did not smoke has a 33% chance of having overt coronary heart disease within 10 years. These models contribute to the estimation of risk and/or health outcomes adjusted for quality of life for use by, amongst others, clinicians, trialists, health planners, guideline developers and health economists.

Stepwise screening for diabetes identifies people with high but modifiable coronary heart disease risk. The ADDITION study

AIMS/HYPOTHESIS

The Anglo-Danish-Dutch study of intensive treatment in people with screen-detected diabetes in primary care (ADDITION) is a pragmatic randomised controlled trial of the effectiveness of intensified multi-factorial treatment on 5 year cardiovascular morbidity and mortality rates in people with screen-detected type 2 diabetes in the Netherlands, UK and Denmark. This paper describes the baseline characteristics of the study population, their estimated risk of coronary heart disease and the extent to which that risk is potentially modifiable.

METHODS

Stepwise screening strategies were performed using risk questionnaires and routine general practice data plus random blood glucose, HbA(1c) and fasting blood glucose measurement. Diabetes was diagnosed using the 1999 World Health Organization criteria and estimated 10 year coronary heart disease risk was calculated using the UK Prospective Diabetes Study risk engine.

RESULTS

Between April 2001 and December 2006, 3,057 people with screen-detected diabetes were recruited to the study (mean age 59.7 years, 58% men) after a stepwise screening programme involving 76,308 people screened in 334 general practices in three countries. Their median estimated 10 year risk of coronary heart disease was 11% in women (interquartile range 7-16%) and 21% (15-30%) in men. There were differences in the distribution of risk factors by country, linked to differences in approaches to screening and the extent to which risk factors had already been detected and treated. The mean HbA(1c) at recruitment was 7.0% (SD 1.6%). Of the people recruited, 73% had a blood pressure > or =140/90 and of these 58% were not on antihypertensive medication. Cholesterol levels were above 5.0 mmol/l in 70% of participants, 91% of whom were not being treated with lipid-lowering drugs.

CONCLUSIONS/INTERPRETATION

People with type 2 diabetes detected by screening and included in the ADDITION study have a raised and potentially modifiable risk of CHD. ClinicalTrials.gov ID no.: NCT 00237549.

Different strategies for screening and prevention of type 2 diabetes in adults: cost effectiveness analysis

OBJECTIVE

To compare four potential screening strategies, and subsequent interventions, for the prevention and treatment of type 2 diabetes: (a) screening for type 2 diabetes to enable early detection and treatment, (b) screening for type 2 diabetes and impaired glucose tolerance, intervening with lifestyle interventions in those with a diagnosis of impaired glucose tolerance to delay or prevent diabetes, (c) as for (b) but with pharmacological interventions, and (d) no screening.

DESIGN

Cost effectiveness analysis based on development and evaluation of probabilistic, comprehensive economic decision analytic model, from screening to death.

SETTING

A hypothetical population, aged 45 at time of screening, with above average risk of diabetes.

DATA SOURCES

Published clinical trials and epidemiological studies retrieved from electronic bibliographic databases; supplementary data obtained from the Department of Health statistics for England and Wales, the screening those at risk (STAR) study, and the Leicester division of the ADDITION study.

METHODS

A hybrid decision tree/Markov model was developed to simulate the long term effects of each screening strategy, in terms of both clinical and cost effectiveness outcomes. The base case model assumed a 50 year time horizon with discounting of both costs and benefits at 3.5%. Sensitivity analyses were carried out to investigate assumptions of the model and to identify which model inputs had most impact on the results.

RESULTS

Estimated costs for each quality adjusted life year (QALY) gained (discounted at 3.5% a year for both costs and benefits) were pound14,150 (euro17 560; $27,860) for screening for type 2 diabetes, pound6242 for screening for diabetes and impaired glucose tolerance followed by lifestyle interventions, and pound7023 for screening for diabetes and impaired glucose tolerance followed by pharmacological interventions, all compared with no screening. At a willingness-to-pay threshold of pound20,000 the probability of the intervention being cost effective was 49%, 93%, and 85% for each of the active screening strategies respectively.

CONCLUSIONS

Screening for type 2 diabetes and impaired glucose tolerance, with appropriate intervention for those with impaired glucose tolerance, in an above average risk population aged 45, seems to be cost effective. The cost effectiveness of a policy of screening for diabetes alone, which offered no intervention to those with impaired glucose tolerance, is still uncertain.

Screening for and prevention of type 2 diabetes

Intervention should be sooner rather than later, even though exact costs and benefits are uncertain

HCV and diabetes. A two-question-based reappraisal

We used available studies to answer two clinically relevant questions, i.e. whether those with type 2 diabetes should undergo hepatitis C virus screening and whether hepatitis C virus positive individuals should be screened for diabetes. Four reasons argue against the hypothesis of screening diabetics for hepatitis C virus. First, although it induces insulin resistance, hepatitis C virus is not directly diabetogenic. Second, the clinical phenotype of hepatitis C virus-associated type 2 diabetes might be a clue to target the specific diabetic population to be screened. Third, diabetic patients are expected to be poor responders to antivirals and evidence that this might result in recovery from type 2 diabetes is insufficient. Fourth, no econometric data are available in the specific subset of those with type 2 diabetes. Case finding of type 2 diabetes in those with hepatitis C virus infection, in contrast, might be considered in those patients with type 2 diabetes who have cirrhosis, in whom--due to increased prevalence and severity of hepatic encephalopathy--diabetes is associated with increased mortality. Preliminary evidence suggests that the prognosis of cirrhosis might benefit from improved glycemic control and thus from earlier diagnosis of type 2 diabetes. Finally, studies are needed to ascertain the most cost-effective strategy of case-finding type 2 diabetes among those who are hepatitis C virus-infected. In conclusion, available data enabled us to answer the two questions. Hepatitis C virus screening should best be restricted to those (lean) diabetic patients with (advanced) liver disease. Glucose tolerance testing should best be performed in those with hepatitis C virus-related cirrhosis. However, additional studies are needed to support the cost-effectiveness of our conclusions.