Are people with negative diabetes screening tests falsely reassured? Parallel group cohort study embedded in the ADDITION (Cambridge) randomised controlled trial

Exploring in-vivo infrared spectroscopy for nail-based diabetes screening

Diabetes screening is traditionally complex, inefficient, and reliant on invasive sampling. This study evaluates near-infrared spectroscopy for non-invasive detection of glycated keratin in nails in vivo. Glycation of keratin, prevalent in tissues like nails and skin, is a key indicator of T2DM risk. In this study involving 200 participants (100 with diabetes, 100 without), NIR's efficacy was compared against a point-of-care HbA1c analyzer. Results showed a specificity of 92.9% in diabetes risk assessment. This study highlights the proposed NIR system potential as a simple, reliable tool for early diabetes screening and risk management in various healthcare settings.

Use of smartphone application versus written titration charts for basal insulin titration in adults with type 2 diabetes and suboptimal glycaemic control (My Dose Coach): multicentre, open-label, parallel, randomised controlled trial

Background

The majority of people with type 2 diabetes who require insulin therapy use only basal insulin in combination with other anti-diabetic agents. We tested whether using a smartphone application to titrate insulin could improve glycaemic control in people with type 2 diabetes who use basal insulin.

Methods

This was a 12-week, multicentre, open-label, parallel, randomised controlled trial conducted in 36 diabetes practices in Germany. Eligible participants had type 2 diabetes, a BMI ≥25.0 kg/m2, were on basal insulin therapy or were initiating basal insulin therapy, and had suboptimal glycaemic control (HbA1c >7.5%; 58.5 mmol/mol). Block randomisation with 1:1 allocation was performed centrally. Participants in the intervention group titrated their basal insulin dose using a smartphone application (My Dose Coach) for 12 weeks. Control group participants titrated their basal insulin dose according to a written titration chart. The primary outcome was the baseline-adjusted change in HbA1c at 12 weeks. The intention-to-treat analysis included all randomised participants.

Results

Between 13 July 2021 and 21 March 2022, 251 study participants were randomly assigned (control group: n = 123; intervention group: n = 128), and 236 completed the follow-up phase (control group: n = 119; intervention group: n = 117). Regarding the HbA1c a model-based adjusted between-group difference of -0.31% (95% CI: 0.01%-0.69%; p = 0.0388) in favour of the intervention group was observed. There were 30 adverse events reported: 16 in the control group, 14 in the intervention group. Of these, 15 adverse events were serious. No event was considered to be related to the investigational device.

Interpretation

Study results suggest that utilizing this digital health smartphone application for basal insulin titration may have resulted in a comparatively greater reduction in HbA1c levels among individuals with type 2 diabetes, as compared to basal insulin titration guided by a written titration schedule. No negative effect on safety outcomes was observed.

Funding

Sanofi-Aventis Deutschland GmbH.

Measurement of Perceived Risk of Developing Diabetes Mellitus: A Systematic Literature Review

BACKGROUND

This systematic review describes approaches to measuring perceived risk of developing type 2 diabetes among individuals without diagnoses and describes the use of theories, models, and frameworks in studies assessing perceived risk. While a systematic review has synthesized perceived risk of complications among individuals with diabetes, no reviews have systematically assessed how perceived risk is measured among those without a diagnosis.

METHODS

Medline, PubMed, PsycINFO, and CINAHAL databases were searched for studies conducted through October 2022 with measures of perceived risk among adults ≥ 18 years without a diabetes diagnosis. Extracted data included study characteristics, measures, and health behavior theories, models, or frameworks used.

RESULTS

Eighty-six studies met inclusion criteria. Six examined perceived risk scales' psychometric properties. Eighty measured perceived risk using (1) a single item; (2) a composite score from multiple items or subconstructs; and (3) multiple subconstructs but no composite score. Studies used items measuring "comparative risk," "absolute or lifetime risk," and "perceived risk" without defining how each differed. Sixty-four studies used cross-sectional designs. Twenty-eight studies mentioned use of health behavior theories in study design or selection of measures.

DISCUSSION

There was heterogeneity in how studies operationalized perceived risk; only one third of studies referenced a theory, model, or framework as guiding design or scale and item selection. Use of perceived lifetime risk, absolute risk, or comparative risk limits comparisons across studies. Consideration of context, target population, and how data are utilized is important when selecting measures; we present a series of questions to ask when selecting measures for use in research and clinical settings. This review is the first to categorize how perceived risk is measured in the diabetes prevention domain; most literature focuses on perceived risk among those with diabetes diagnoses. Limitations include exclusion of non-English and gray literature and single reviewer screening and data extraction.

Screening for Diabetes and Prediabetes

Overt type 2 diabetes mellitus (T2DM) is preceded by prediabetes and latent diabetes (lasts 9-12 years). Key dysglycemia screening tests are fasting plasma glucose and hemoglobin A1C. Screen-detected T2DM benefits from multifactorial management of cardiovascular risk beyond glycemia. Prediabetes is best addressed by lifestyle modification, with the goal of preventing T2DM. Although there is no trial evidence of prediabetes/T2DM screening effectiveness, simulations suggest that clinic-based opportunistic screening of high-risk individuals is cost-effective. The most rigorous extant recommendations are those of the American Diabetes Association and US Preventive Services Task Force, which advise opportunistic 3-yearly screening.

Psychological impact of providing women with personalised 10-year breast cancer risk estimates

Background

The Predicting Risk of Cancer at Screening (PROCAS) study estimated 10-year breast cancer risk for 53,596 women attending NHS Breast Screening Programme. The present study, nested within the PROCAS study, aimed to assess the psychological impact of receiving breast cancer risk estimates, based on: (a) the Tyrer–Cuzick (T-C) algorithm including breast density or (b) T-C including breast density plus single-nucleotide polymorphisms (SNPs), versus (c) comparison women awaiting results.

Methods

A sample of 2138 women from the PROCAS study was stratified by testing groups: T-C only, T-C(+SNPs) and comparison women; and by 10-year risk estimates received: 'moderate' (5–7.99%), 'average' (2–4.99%) or 'below average' (<1.99%) risk. Postal questionnaires were returned by 765 (36%) women.

Results

Overall state anxiety and cancer worry were low, and similar for women in T-C only and T-C(+SNPs) groups. Women in both T-C only and T-C(+SNPs) groups showed lower-state anxiety but slightly higher cancer worry than comparison women awaiting results. Risk information had no consistent effects on intentions to change behaviour. Most women were satisfied with information provided. There was considerable variation in understanding.

Conclusions

No major harms of providing women with 10-year breast cancer risk estimates were detected. Research to establish the feasibility of risk-stratified breast screening is warranted.

Considerations in the design of randomized trials to screen for type 2 diabetes

Background Randomized controlled trials (RCTs) are the most robust and valid approach to evaluate screening for diseases. Many in the diabetes research community have advocated sole reliance on RCTs for designing diabetes screening policies. However, the challenges of conducting RCTs of screening for type 2 diabetes may have been underappreciated. Purpose Discuss the key theoretical concepts and practical challenges of designing and conducting RCTs of diabetes screening. Methods Narrative and critical review of the literature pertaining to the theory and practice of designing and conducting RCTs of diabetes screening. Results We present the theoretical basis of a diabetes screening trial, using concepts developed mainly in studies of cancer screening and illustrations from the Cambridge component of the Anglo Danish Dutch Study of Intensive Treatment In peOple with screeN-detected diabetes in primary care (ADDITION-Cambridge), the only extant trial of diabetes screening. We examine design issues, including the appropriate trial question, choice of design, and duration of follow-up, and address aspects of trial implementation, including recruitment, randomization, endpoint determination, sample size requirements, and screening interval. Limitations The limited number of trials of diabetes screening did not permit us to illustrate many of the practical difficulties one encounters when implementing theoretical concepts. Conclusion When diabetes screening trials are planned, we suggest careful consideration to potential areas of practical difficulty, especially the need for particularly large sample sizes and extended follow-up, and the choice of appropriate outcomes and screening intervals.

Do negative screening test results cause false reassurance? A systematic review

PURPOSE

It has been suggested that receiving a negative screening test result may cause false reassurance or have a 'certificate of health effect'. False reassurance in those receiving a negative screening test result may result in them wrongly believing themselves to be at lower risk of the disease, and consequently less likely to engage in health-related behaviours that would lower their risk.

METHODS

The present systematic review aimed to identify the evidence regarding false reassurance effects due to negative screening test results in adults (over 18 years) screened for the presence of a disease or its precursors, where disease or precursors are linked to lifestyle behaviours. MEDLINE and PsycINFO were searched for trials that compared a group who had received negative screening results to an unscreened control group. The following outcomes were considered as markers of false reassurance: perceived risk of disease; anxiety and worry about disease; health-related behaviours or intention to change health-related behaviours (i.e., smoking, diet, physical activity, and alcohol consumption); self-rated health status.

RESULTS

Nine unique studies were identified, reporting 55 measures in relation to the outcomes considered. Outcomes were measured at various time points from immediately following screening to up to 11 years after screening. Despite considerable variation in outcome measures used and timing of measurements, effect sizes for comparisons between participants who received negative screening test results and control participants were typically small with few statistically significant differences. There was evidence of high risk of bias, and measures of behaviours employed were often not valid.

CONCLUSIONS

The limited evidence base provided little evidence of false reassurance following a negative screening test results on any of four outcomes examined. False reassurance should not be considered a significant harm of screening, but further research is warranted. Statement of contribution What is already known on this subject? It has been argued that screening for disease may cause 'false reassurance' whereby those who receive a negative screening test result wrongly interpret their result as indicating they are less likely to develop the disease in future. There is some evidence for false reassurance, but the relevant studies consider a range of diseases and possible indicators of false reassurance (i.e., risk perceptions, lifestyle behaviours, emotional outcomes, and quality of life). For these reasons, it is currently unclear that the extent to receive negative screening test results is likely to impact on participants' lifestyle behaviours, or other possible indicators of false reassurance. What does this study add? Current available evidence shows that negative screening test results are unlikely to cause false reassurance and, in particular, are unlikely to have a negative impact on lifestyle behaviours. Given the limitations of the current evidence base in terms of number of studies and study quality, future research should continue to explore this issue, where this can be done at low cost.

Adherence to NICE guidelines on diabetes prevention in the UK: Effect on patient knowledge and perceived risk

BACKGROUND

NICE Guidelines for prevention of diabetes include identifying people at risk followed by cost-effective intervention if necessary. Based on assessment of risk via a questionnaire and/or blood test the intervention may comprise a brief discussion of risk factors and preventive advice or referral to intensive lifestyle intervention.

DESIGN AND SETTING

In this cross-sectional study 59 subjects recruited from local GP practices were invited by letter to attend a screening for a diabetes prevention study.

METHOD

Following a telephone screening during which subjects were asked whether they had been informed if they were at high-risk of type 2 diabetes, eligible subjects completed a Risk Perception Survey for Developing Diabetes (RPS-DD), a validated diabetes risk score and underwent an oral glucose tolerance test (OGTT) at a medical screening.

RESULTS

As measured by the Diabetes UK Risk Score, 44.1% were at high risk, 42.4% moderate risk and 13.6% at increased risk. 42% of patients had been informed they were at high-risk by a health professional. Those who had been informed of their risk had significantly higher perceived risk scores (p<0.001), higher knowledge scores (p<0.001) and decreased optimism scores (p=0.004), but were not more aware that diet (p=0.42) and weight management (p=0.57) can play a role in preventing diabetes.

CONCLUSIONS

People at high-risk of diabetes are not being informed of their risk status as recommended by NICE guidelines. There is scope for education for health professionals and the public.

Early Detection and Treatment of Type 2 Diabetes Reduce Cardiovascular Morbidity and Mortality: A Simulation of the Results of the Anglo-Danish-Dutch Study of Intensive Treatment in People With Screen-Detected Diabetes in Primary Care (ADDITION-Europe)

OBJECTIVE

To estimate the benefits of screening and early treatment of type 2 diabetes compared with no screening and late treatment using a simulation model with data from the ADDITION-Europe study.

RESEARCH DESIGN AND METHODS

We used the Michigan Model, a validated computer simulation model, and data from the ADDITION-Europe study to estimate the absolute risk of cardiovascular outcomes and the relative risk reduction associated with screening and intensive treatment, screening and routine treatment, and no screening with a 3- or 6-year delay in the diagnosis and routine treatment of diabetes and cardiovascular risk factors.

RESULTS

When the computer simulation model was programmed with the baseline demographic and clinical characteristics of the ADDITION-Europe population, it accurately predicted the empiric results of the trial. The simulated absolute risk reduction and relative risk reduction were substantially greater at 5 years with screening, early diagnosis, and routine treatment compared with scenarios in which there was a 3-year (3.3% absolute risk reduction [ARR], 29% relative risk reduction [RRR]) or a 6-year (4.9% ARR, 38% RRR) delay in diagnosis and routine treatment of diabetes and cardiovascular risk factors.

CONCLUSIONS

Major benefits are likely to accrue from the early diagnosis and treatment of glycemia and cardiovascular risk factors in type 2 diabetes. The intensity of glucose, blood pressure, and cholesterol treatment after diagnosis is less important than the time of its initiation. Screening for type 2 diabetes to reduce the lead time between diabetes onset and clinical diagnosis and to allow for prompt multifactorial treatment is warranted.

Long-term effect of population screening for diabetes on cardiovascular morbidity, self-rated health, and health behavior

PURPOSE

There is limited trial evidence concerning the long-term effects of screening for type 2 diabetes on population morbidity. We examined the effect of a population-based diabetes screening program on cardiovascular morbidity, self-rated health, and health-related behaviors.

METHODS

We conducted a pragmatic, parallel-group, cluster-randomized controlled trial of diabetes screening (the ADDITION-Cambridge study) including 18,875 individuals aged 40 to 69 years at high risk of diabetes in 32 general practices in eastern England (27 practices randomly allocated to screening, 5 to no-screening for control). Of those eligible for screening, 466 (2.9%) were diagnosed with diabetes. Seven years after randomization, a random sample of patients was sent a postal questionnaire: 15% from the screening group (including diabetes screening visit attenders and non-attenders) and 40% from the no-screening control group. Self-reported cardiovascular morbidity, self-rated health (using the SF-8 Health Survey and EQ-5D instrument), and health behaviors were compared between trial groups using an intention-to-screen analysis.

RESULTS

Of the 3,286 questionnaires mailed out, 1,995 (61%) were returned, with 1,945 included in the analysis (screening: 1,373; control: 572). At 7 years, there were no significant differences between the screening and control groups in the proportion of participants reporting heart attack or stroke (OR = 0.90, 95% CI, 0.71-1.15); SF-8 physical health summary score as an indicator of self-rated health status (β -0.33, 95% CI, -1.80 to 1.14); EQ-5D visual analogue score (β: 0.80, 95% CI, -1.28 to 2.87); total physical activity (β 0.50, 95% CI, -4.08 to 5.07); current smoking (OR 0.97, 95% CI, 0.72 to 1.32); and alcohol consumption (β 0.14, 95% CI, -1.07 to 1.35).

CONCLUSIONS

Invitation to screening for type 2 diabetes appears to have limited impact on population levels of cardiovascular morbidity, self-rated health status, and health behavior after 7 years.

Impact of a diabetes screening program on a rural Chinese population: a 3-year follow-up study

BACKGROUND

Screening for type 2 diabetes helps detect previously unknown diabetes and identify people with pre-diabetes, but the adverse impact of such screening on individuals labelled as pre-diabetes or classified as normal, is less known. In this study the health-related quality of life (HRQoL), depression and lifestyle changes in a rural Chinese population are assessed three years after a screening program.

METHODS

A total of 647 (39.1%) individuals with pre-diabetes and 1009 (60.9%) individuals with normoglycaemia from a population-based diabetes screening program in 2009 were re-examined in 2012-2013. Changes at the end of 3 years in HRQoL, depression, BMI, weight, frequency of physical activity and vegetable intake were assessed.

RESULTS

In men with normoglycaemia the mean (SD) 15D scores were 0.974 (0.04) at baseline and 0.973 (0.05) at follow-up; and 0.971 (0.05) and 0.966 (0.06) for men with pre-diabetes. In women the scores were 0.973 (0.05) and 0.963 (0.06) for normoglycaemia and 0.959 (0.06) and 0.954 (0.07) for pre-diabetes, respectively. Compared to baseline, the HRQoL was slightly lower at 3 years in all groups but the change was not considered to be clinically important, and was only statistically significant for women with normoglycaemia (p < 0.05). The depression score was slightly elevated in women, but not in men. No significant changes in BMI were noticed, but weight increased slightly in the normoglycemia group (p < 0.05). Screening had a significant positive impact on physical activity and vegetable intake.

CONCLUSIONS

This population-based diabetes screening program generated long-term positive changes toward a healthy lifestyle as measured by physical activity and vegetable intake for all the participants without adverse effects on the HRQoL and depression.

Screening for type 2 diabetes in a high-risk population: effects of a negative screening test after 4 years follow-up

BACKGROUND

A negative diabetes screening test may unintentionally provide reassurance, resulting in reduced incentive to follow a healthy lifestyle.

PURPOSE

The purpose of this study is to assess negative test result effects on lifestyle and risk perception at 4 years follow-up.

METHODS

Risk perception and changes in smoking, physical activity, body mass index (BMI), and waist circumference were compared between 706 high-risk participants with a negative test result and 706 high-risk participants not offered screening (controls) in a randomized controlled trial of diabetes screening.

RESULTS

Negative-screened individuals experienced a small but significant increase in BMI and waist circumference, but there was no significant difference with controls. The negative-screened group had significantly higher perception of risk of developing diabetes (p = 0.009) than controls, but no differences were observed in perceived personal control, worry, and optimistic bias.

CONCLUSION

Screening negative for diabetes did not lead to overt long-term changes in lifestyle, despite a high perception of risk of developing diabetes. (ISRCTN75983009.).

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.

Detecting type 2 diabetes and prediabetes among asymptomatic adults in the United States: modeling American Diabetes Association versus US Preventive Services Task Force diabetes screening guidelines

BACKGROUND

Screening to detect prediabetes and diabetes enables early prevention and intervention. This study describes the number and characteristics of asymptomatic, undiagnosed adults in the United States who could be detected with prediabetes and type 2 diabetes using the American Diabetes Association (ADA) guidelines compared to the United States Preventive Services Task Force (USPSTF) guidelines.

METHODS

We developed predictive models for undiagnosed diabetes and prediabetes using polytomous logistic regression from data on risk factors in the 2003-2010 National Health and Nutrition Examination Survey (n = 19,056). We applied these predictive models to the 2010 Medical Expenditure Panel Survey, which contains health care use data, to generate probabilities of undiagnosed diabetes and undetected prediabetes for each adult. We summed individual probabilities to estimate the number of adults who would be detected with prediabetes and/or type 2 diabetes if screened under ADA or USPSTF guidelines. We analyzed health care use patterns of people at high risk for diabetes.

RESULTS

In 2010, 59.1 million adults met the USPSTF screening criteria including 24.4 million people with undetected prediabetes and 3.7 million people with undiagnosed diabetes. In comparison, among the 86.3 million people who met the ADA screening criteria, there were 33.9 million with undetected prediabetes and 4.6 million with undiagnosed type 2 diabetes. The ADA guidelines detected 38.9% more cases of prediabetes and 24.3% more cases of type 2 diabetes compared to the USPSTF guidelines. Subgroup analysis showed that ADA guidelines would detect 78% more cases of diabetes among the age 54 and younger population, in 40% more blacks, and in more than twice as many Hispanics than USPSTF guidelines. Only 58% of adults meeting ADA guidelines and 70% meeting USPSTF guidelines had ≥ 1 primary care office visit in 2010.

CONCLUSIONS

Compared to USPSTF guidelines, ADA guidelines would screen more people and detect more cases of both prediabetes and type 2 diabetes, though a substantial percentage of patients with undetected cases had no contact with a primary care provider in 2010. Addressing the problem of large numbers of undetected prediabetes and type 2 diabetes cases will require new strategies for screening.

'I saw what the future direction would be...': experiences of diabetes risk and physical activity after diabetes screening

OBJECTIVES

To improve understanding of how individuals at high risk of type 2 diabetes experience the risk of diabetes and how these experiences relate to the adoption of physical activity as a protective behaviour.

DESIGN

A qualitative study using semi-structured interview with individuals identified by screening as at high risk of type 2 diabetes.

METHODS

Fourteen individuals, aged 40-64, were interviewed twice, with a 2-year interval between. Participants' experiences of their risk of diabetes and physical activity were assessed. The transcribed interview data were analysed using inductive qualitative content analysis.

RESULTS

Two themes emerged from the data: a threatening risk perception and a rejected risk perception. The threatening risk perception occurred when the risk was unexpected by the participant, but became internalized through the screening procedure. The threatening perception also involved a commitment to increase physical activity to prevent diabetes. However, short-term anxiety and subsequently emerging hopelessness were also part of this perception. The rejected risk perception involved indifference and scepticism regarding the risk. Here, physical activity behaviour and cognitions appeared to remain unchanged. Rejection also involved difficulties in accepting one's high-risk identity. The rejecting group lacked motivation for increased physical activity, while the other group showed determination regarding increased physical activity, often leading to success.

CONCLUSION

Perceptions of the risk of diabetes emerged as threatening or as rejected. Participants' perceptions reflected varying and intertwining emotional, cognitive, and behavioural mechanisms for coping with the risk, all of which should be recognized in promoting physical activity among high-risk individuals. Statement of contribution What is already known on this subject? Diabetes screening has few adverse psychological effects on screened individuals. Diabetes can be prevented by increased physical activity and modest weight loss among high-risk individuals. The evidence on the effects of screening on protective behaviour is limited and inconsistent. What does this study add? High-risk individuals' threatening perception of risk appears encouraging increased physical activity. Individuals having problems in adjusting to high-risk identification may not be motivated to engage in physical activity for prevention. Failure to achieve the outcomes expected from lifestyle changes may lead people with threatening risk perception to a sense of hopelessness.

Using web-based familial risk information for diabetes prevention: a randomized controlled trial

Background

It has been suggested that family history information may be effective in motivating people to adopt health promoting behaviour. The aim was to determine if diabetic familial risk information by using a web-based tool leads to improved self-reported risk-reducing behaviour among individuals with a diabetic family history, without causing false reassurance among those without a family history.

Methods

An online sample of 1,174 healthy adults aged 35–65 years with a BMI ≥ 25 was randomized into two groups receiving an online diabetes risk assessment. Both arms received general tailored diabetes prevention information, whilst the intervention arm also received familial risk information after completing a detailed family history questionnaire. Separate analysis was performed for four groups (family history group: 286 control versus 288 intervention group; no family history: 269 control versus 266 intervention group). Primary outcomes were self-reported behavioural outcomes: fat intake, physical activity, and attitudes towards diabetes testing. Secondary outcomes were illness and risk perceptions.

Results

For individuals at familial risk there was no overall intervention effect on risk-reducing behaviour after three months, except for a decrease in self-reported saturated fat intake among low-educated individuals (Beta (b) -1.01, 95% CI −2.01 to 0.00). Familial risk information resulted in a decrease of diabetes risk worries (b −0.21, -0.40 to −0.03). For individuals without family history no effect was found on risk-reducing behaviour and perceived risk. A detailed family history assessment resulted in a greater percentage of individuals reporting a familial risk for diabetes compared to a simple enquiry.

Conclusions

Web-based familial risk information reduced worry related to diabetes risk and decreased saturated fat intake of those at greatest need of preventative care. However, the intervention was not effective for the total study population on improving risk-reducing behaviour. The emphasis on familial risk does not seem to result in false reassurance among individuals without family history. Additionally, a detailed family history questionnaire identifies more individuals at familial risk than a simple enquiry.

Trial registration

NTR1938

Screening for type 2 diabetes and population mortality over 10 years (ADDITION-Cambridge): a cluster-randomised controlled trial

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, uncertainty persists around the benefits of screening for type 2 diabetes. We assessed the effect of a population-based stepwise screening programme on mortality.

METHODS

In a pragmatic parallel group, cluster-randomised trial, 33 general practices in eastern England were randomly assigned by the method of minimisation in an unbalanced design to: screening followed by intensive multifactorial treatment for people diagnosed with diabetes (n=15); screening plus routine care of diabetes according to national guidelines (n=13); and a no-screening control group (n=5). The study population consisted of 20,184 individuals aged 40-69 years (mean 58 years), at high risk of prevalent undiagnosed diabetes, on the basis of a previously validated risk score. In screening practices, individuals were invited to a stepwise programme including random capillary blood glucose and glycated haemoglobin (HbA(1c)) tests, a fasting capillary blood glucose test, and a confirmatory oral glucose tolerance test. The primary outcome was all-cause mortality. All participants were flagged for mortality surveillance by the England and Wales Office of National Statistics. Analysis was by intention-to-screen and compared all-cause mortality rates between screening and control groups. This study is registered, number ISRCTN86769081.

FINDINGS

Of 16,047 high-risk individuals in screening practices, 15,089 (94%) were invited for screening during 2001-06, 11,737 (73%) attended, and 466 (3%) were diagnosed with diabetes. 4137 control individuals were followed up. During 184,057 person-years of follow up (median duration 9·6 years [IQR 8·9-9·9]), there were 1532 deaths in the screening practices and 377 in control practices (mortality hazard ratio [HR] 1·06, 95% CI 0·90-1·25). We noted no significant reduction in cardiovascular (HR 1·02, 95% CI 0·75-1·38), cancer (1·08, 0·90-1·30), or diabetes-related mortality (1·26, 0·75-2·10) associated with invitation to screening.

INTERPRETATION

In this large UK sample, screening for type 2 diabetes in patients at increased risk was not associated with a reduction in all-cause, cardiovascular, or diabetes-related mortality within 10 years. The benefits of screening might be smaller than expected and restricted to individuals with detectable disease.

FUNDING

Wellcome Trust; UK Medical Research Council; National Health Service research and development support; UK National Institute for Health Research; University of Aarhus, Denmark; Bio-Rad.

Estimating the potential population impact of stepwise screening strategies for identifying and treating individuals at high risk of Type 2 diabetes: a modelling study

BACKGROUND

Diabetes risk assessment has been proposed as part of the National Health Service Health Checks programme, and HbA(1c) has recently been recommended as a diagnostic test for diabetes at a threshold of 48 mmol/mol (6.5%). We estimated the potential population impact of different stepwise screening strategies to identify individuals at high risk who might be offered preventive interventions.

METHODS

Using data from 5910 participants in the European Prospective Investigation of Cancer (EPIC)-Norfolk cohort with HbA(1c) measurements, we modelled different stepwise screening strategies for identifying and treating individuals at high risk of Type 2 diabetes using different HbA(1c) cut-off points with and without a stage of prestratification. For each strategy, we estimated the number needed to have a diagnostic test, the number needed to treat to prevent one new case of Type 2 diabetes, and the number of new cases that could be prevented in the population over 3 years. Relative risk reductions for estimated effects of intensive lifestyle intervention were derived from the US Diabetes Prevention Program.

RESULTS

Compared with inviting all individuals in an average primary care trust for a diagnostic test, a stepwise screening approach using simple routine data such as age and anthropometric indices could prevent a slightly lower number (lower-upper estimates) of new cases of Type 2 diabetes over 3 years (224 [130-359] and 193 [109-315] cases respectively) but would only require half the population to be invited for a diagnostic blood test. A total of 162 (88-274) cases could be prevented by inviting individuals with a Cambridge risk score of ≥ 0.15, with only 40% of the total population requiring diagnostic blood tests. Using a participant completed questionnaire for risk assessment (FINDRISC) was less effective, mainly relating to the questionnaire response rate. Providing preventive interventions to those with a lower HbA(1c) of 37-< 48 mmol/mol (5.5-< 6.5%) could prevent more cases but with a disproportionately higher workload, compared with using the recommended HbA(1c) threshold of 42-< 48 mmol/mol (6.0-< 6.5%).

CONCLUSIONS

Compared with mass screening, an approach using routine data for risk stratification followed by an HbA(1c) test with a threshold of 42-< 48 mmol/mol (6.0-< 6.5%) for identifying individuals suitable for preventive interventions might prevent slightly fewer cases of Type 2 diabetes but with potential cost-savings.

Effect of screening for Type 2 diabetes on population-level self-rated health outcomes and measures of cardiovascular risk: 13-year follow-up of the Ely cohort

AIMS

There is continuing uncertainty regarding the overall net benefits of population-based screening for Type 2 diabetes. We compared clinical measures, prescribed medication, cardiovascular morbidity and self-rated health in individuals without diabetes in a screened vs. an unscreened population.

METHODS

A parallel-group, cohort study of people aged 40-65 years, free of known diabetes, identified from the population register of a general practice in Ely, Cambridgeshire (n = 4936). In 1990-1992, one third (n = 1705), selected randomly, received an invitation for screening for diabetes and cardiovascular risk factors at 5-yearly intervals (screened population). From the remainder of the sampling frame, 1705 randomly selected individuals were invited to diabetes screening 10 years later (unscreened population). Patients without known diabetes from both populations were invited for a health assessment.

RESULTS

Of 3390 eligible individuals without diabetes, 1442 (43%) attended for health assessment, with no significant difference in attendance between groups. Thirteen years after the commencement of screening, self-rated functional health status and health utility were identical between the screened and unscreened populations. Clinical measures, self-reported medication and cardiovascular morbidity were similar between the two groups.

CONCLUSIONS

Screening for diabetes is not associated with long-term harms at the population level. However, screening has limited long-term impact on those testing negative; benefits may largely be restricted to those whose diabetes is detected early through screening.

Screening for diabetes: hope and despair

This commentary discusses whether screening for type 2 diabetes or earlier normalisation of blood glucose levels or initiation of non-antihyperglycaemic agents or any other diabetes-specific treatment can help reduce the excess associated risks for macrovascular morbidity and mortality. The available data indicate that screening with the sole aim of decreasing the lead time between diagnosis and treatment is very unlikely to reduce these risks. In contrast to macrovascular complications, some microvascular events such as background retinopathy could theoretically be prevented by earlier diagnosis and better glycaemic control, particularly in relatively young type 2 diabetic patients. This, however, remains to be shown in controlled prospective intervention trials.

Analysis & commentary: Global prevention and control of type 2 diabetes will require paradigm shifts in policies within and among countries

Continued increases in the prevalence of and disproportionate health spending associated with type 2 diabetes argue for policies focused on preventing that condition and treating it appropriately, even as we strive to improve coordination of care for coexisting chronic diseases. This article argues that four policy paradigm shifts will be necessary to achieve that specific emphasis on type 2 diabetes: conceptually integrating primary and secondary prevention along a clinical continuum; recognizing the central importance of early detection of prediabetes and undiagnosed diabetes in implementing cost-effective prevention and control; integrating community and clinical expertise, and resources, within organized and affordable service delivery systems; and sharing and adopting evidence-based policies at the global level.

Atherosclerosis screening by noninvasive imaging for cardiovascular prevention: a systematic review

BACKGROUND

Noninvasive imaging of atherosclerosis is being increasingly used in clinical practice, with some experts recommending to screen all healthy adults for atherosclerosis and some jurisdictions mandating insurance coverage for atherosclerosis screening. Data on the impact of such screening have not been systematically synthesized.

OBJECTIVES

We aimed to assess whether atherosclerosis screening improves cardiovascular risk factors (CVRF) and clinical outcomes.

DESIGN

This study is a systematic review.

DATA SOURCES

We searched MEDLINE and the Cochrane Clinical Trial Register without language restrictions.

STUDY ELIGIBILITY CRITERIA

We included studies examining the impact of atherosclerosis screening with noninvasive imaging (e.g., carotid ultrasound, coronary calcification) on CVRF, cardiovascular events, or mortality in adults without cardiovascular disease.

RESULTS

We identified four randomized controlled trials (RCT, n=709) and eight non-randomized studies comparing participants with evidence of atherosclerosis on screening to those without (n=2,994). In RCTs, atherosclerosis screening did not improve CVRF, but smoking cessation rates increased (18% vs. 6%, p=0.03) in one RCT. Non-randomized studies found improvements in several intermediate outcomes, such as increased motivation to change lifestyle and increased perception of cardiovascular risk. However, such data were conflicting and limited by the lack of a randomized control group. No studies examined the impact of screening on cardiovascular events or mortality. Heterogeneity in screening methods and studied outcomes did not permit pooling of results.

CONCLUSION

Available evidence about atherosclerosis screening is limited, with mixed results on CVRF control, increased smoking cessation in one RCT, and no data on cardiovascular events. Such screening should be validated by large clinical trials before widespread use.

Motivation and experiences of self-testers regarding tests for cardiovascular risk factors

BACKGROUND

In recent years, self-tests have become increasingly available to the general public, though their value is still being debated. Because these tests are available, consumers should have access to clear information about self-testing. Examining experiences of self-testers could contribute to the development of consumer information.

OBJECTIVE

Detailed exploration of consumers' experiences with self-testing for cardiovascular risk factors.

METHODS

Semi-structured interviews with 20 consumers who had performed a self-test for glucose, cholesterol or albuminuria. The main topics of the interviews were reasons for self-testing, performing the self-test, follow-up behaviour and perceived need for information on self-testing. Data were analysed using thematic content analysis.

RESULTS

Regarding the reason for self-testing, three types of users were distinguished: those who engaged in self-testing when a test was offered, either with or without previous knowledge about the disease or risk factor, and those who had actively decided to test and had searched for a self-test themselves. Self-testers had generally experienced no problems performing the test or interpreting the result and had considerable confidence in the result. They were easily reassured by a normal result, while an abnormal result did not automatically mean they consulted a doctor. Most participants did not feel the need for more information.

CONCLUSIONS

Self-testers often perform tests for reassurance, without considering the disadvantages, such as the absence of professional counselling and the risk of false-positive or false-negative results. Consumer information should promote more informed and deliberate choices for self-testing.

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.

Impact and cost of a 2-week community-based screening and awareness program for diabetes and cardiovascular risk factors in a Swiss canton

BACKGROUND

Community-based diabetes screening programs can help sensitize the population and identify new cases. However, the impact of such programs is rarely assessed in high-income countries, where concurrent health information and screening opportunities are common place.

INTERVENTION AND METHODS

A 2-week screening and awareness campaign was organized as part of a new diabetes program in the canton of Vaud (population of 697,000) in Switzerland. Screening was performed without appointment in 190 out of 244 pharmacies in the canton at the subsidized cost of 10 Swiss Francs per participant. Screening included questions on risk behaviors, measurement of body mass index, blood pressure, blood cholesterol, random blood glucose (RBG), and A1c if RBG was ≥7.0 mmol/L. A mass media campaign promoting physical activity and a healthy diet was channeled through several media, eg, 165 spots on radio, billboards in 250 public places, flyers in 360 public transport vehicles, and a dozen articles in several newspapers. A telephone survey in a representative sample of the population of the canton was performed after the campaign to evaluate the program.

RESULTS

A total of 4222 participants (0.76% of all persons aged ≥18 years) underwent the screening program (median age: 53 years, 63% females). Among participants not treated for diabetes, 3.7% had RBG ≥ 7.8 mmol/L and 1.8% had both RBG ≥ 7.0 mmol/L and A1c ≥ 6.5. Untreated blood pressure ≥140/90 mmHg and/or untreated cholesterol ≥5.2 mmol/L were found in 50.5% of participants. One or several treated or untreated modifiable risk factors were found in 78% of participants. The telephone survey showed that 53% of all adults in the canton were sensitized by the campaign. Excluding fees paid by the participants, the program incurred a cost of CHF 330,600.

CONCLUSION

A community-based screening program had low efficiency for detecting new cases of diabetes, but it identified large numbers of persons with elevated other cardiovascular risk factors. Our findings suggest the convenience of A1c for mass screening of diabetes, the usefulness of extending diabetes screening to other cardiovascular risk factors, and the importance of a robust background communication campaign.

TRAF4 functions as an intermediate of GITR-induced NF-kappaB activation

Members of the tumor necrosis factor receptor (TNFR) family regulate the activation, differentiation, and function of many cell types, including cells of the immune system. TNFR-associated factors (TRAFs) function as adapter molecules controlling signaling pathways triggered by TNFR family members, such as activation of nuclear factor kappaB (NF-kappaB). Despite intensive research, the function of TRAF4 in signaling pathways triggered by TNFR-related proteins remains enigmatic. Intriguingly, our functional studies indicated that TRAF4 augments NF-kappaB activation triggered by glucocorticoid-induced TNFR (GITR), a receptor expressed on T cells, B cells, and macrophages. Further analyses revealed that TRAF4-mediated NF-kappaB activation downstream of GITR depends on a previously mapped TRAF-binding site in the cytoplasmic domain of the receptor and is inhibited by the cytoplasmic protein A20. GITR is thought to inhibit the suppressive function of regulatory T cells (Treg cells) and to promote activation of T cells. Taken together, our studies provide the first indications that TRAF4 elaborates GITR signaling and suggest that TRAF4 can modulate the suppressive functions of Treg cells.