Jette Kolding Kristensen

The Danish National Diabetes Register: trends in incidence, prevalence and mortality

Aims/hypothesisThe aim of the study was to describe trends in the incidence rate, prevalence and mortality rate for diabetes in Denmark.MethodsHealthcare registers at the National Board of Health were used to compile a register of diabetic patients in the Danish population (5.4 million people). Age- and sex-specific prevalence, incidence rates, mortality rates and standardised mortality ratios relative to the non-diabetic part of the population were calculated.ResultsThe register contains records for about 360,000 persons with diabetes; 230,000 were alive at 1 January 2007, corresponding to an overall prevalence of 4.2%. The prevalence increased by 6% per year. In 2004 the incidence rates were 1.8 per 100,000 at age 40 years and 10.0 per 100,000 at age 70 years. The incidence rate increased 5% per year before 2004 and then stabilised. The mortality rate in the diabetic population decreased 4% per year, compared with 2% per year in the non-diabetic part of the population. The mortality rate decreased 40% during the first 3 years after inclusion in the register. The standardised mortality ratio decreased with age, from 4.0 at age 50 years to 2.5 at age 70 years and just under 2 at age 85 years, identically for men and women. The standardised mortality ratio decreased 1% per calendar year. The lifetime risk of diabetes was 30%.Conclusions/interpretationThe prevalence of diabetes in Denmark rose in 1995–2006, but the mortality rate in diabetic patients decreased faster than that of the non-diabetic population. The mortality rate decreased markedly just after inclusion in the register. Incidence rates have shown a tendency to decrease during the last few years, but this finding should be viewed with caution.

The National Diabetes Register

Introduction: A National Diabetes Register was established in the National Board of Health in 2006 following a pilot study showing the feasibility of doing so based on existing registers. Content: The register contains data of birth, date of inclusion, and date of death as well as information on the criteria met for inclusion. Validity and coverage: The register is more than 90% complete when compared to records of general practitioners, and it covers the entire Danish population. Conclusion: The register is a source of demographic information for the diabetes population in itself, but also a source of linkable information for studies of diabetes as outcome and as determinant.

The effect of feedback to general practitioners on quality of care for people with type 2 diabetes. A systematic review of the literature

BackgroundThere have been numerous efforts to improve and assure the quality of treatment and follow-up of people with Type 2 diabetes (PT2D) in general practice. Facilitated by the increasing usability and validity of guidelines, indicators and databases, feedback on diabetes care is a promising tool in this aspect. Our goal was to assess the effect of feedback to general practitioners (GPs) on the quality of care for PT2D based on the available literature.MethodsSystematic review searches were conducted using October 2008 updates of Medline (Pubmed), Cochrane library and Embase databases. Additional searches in reference lists and related articles were conducted. Papers were included if published in English, performed as randomized controlled trials, studying diabetes, having general practice as setting and using feedback to GPs on diabetes care. The papers were assessed according to predefined criteria.ResultsTen studies complied with the inclusion criteria. Feedback improved the care for PT2D, particularly process outcomes such as foot exams, eye exams and Hba1c measurements. Clinical outcomes like lowering of blood pressure, Hba1c and cholesterol levels were seen in few studies. Many process and outcome measures did not improve, while none deteriorated. Meta analysis was unfeasible due to heterogeneity of the studies included. Two studies used electronic feedback.ConclusionBased on this review, feedback seems a promising tool for quality improvement in diabetes care, but more research is needed, especially of electronic feedback.

Diabetes prevalence and quality of diabetes care among Lebanese or Turkish immigrants compared to a native Danish population.

OBJECTIVES To describe Type 2 diabetes prevalence and care among Turkish (T) and Lebanese (L) immigrants as compared to native Danes (DK) in the county of Aarhus. METHOD Data from The National Health Service Registry, The Regional Laboratory Database and The Danish National Hospital Registry were collected from 2000 through 2003 to identify and describe known diabetes in a background population of 244.426 citizens in the age group of 40-70 years living in the County of Aarhus. RESULTS The age-standardised prevalence of Type 2 diabetes was 3.6% (DK), 18.9% (L) and 19.8% (T). In 2003, HbA1c was measured at least once in 84% (DK), 87% (L) and 83% (T) of the patients. In 2003, 72% (DK), 53% (L) and 51% (T) had an HbA1c <8% (p<0.05) and less than 50% of all groups had a total-cholesterol <5.0 mmol/l. In 39% (DK), 35% (L) and 37% (T) of the patients, no examination for retinopathy was registered during the period of 2000-2003. A cardiovascular diagnosis was registered in 27% (DK), 32% (L) and 33% (T) of the patients (p=NS). CONCLUSION Compared to native Danes, Lebanese and Turkish immigrants had a much higher prevalence of Type 2 diabetes and worse glycaemic regulation. The routine monitoring of diabetes care for native Danes, Lebanese or Turkish immigrants were similar. Overall, diabetes care is not satisfactory neither for native Danes, nor Lebanese or Turkish immigrants.

Prenatal exposure to bereavement and type-2 diabetes: a Danish longitudinal population based study.

Background The etiology of type-2 diabetes is only partly known, and a possible role of prenatal stress in programming offspring for insulin resistance has been suggested by animal models. Previously, we found an association between prenatal stress and type-1 diabetes. Here we examine the association between prenatal exposure to maternal bereavement during preconception and pregnancy and development of type-2 diabetes in the off-spring. Methods We utilized data from the Danish Civil Registration System to identify singleton births in Denmark born January 1st 1979 through December 31st 2008 (N = 1,878,246), and linked them to their parents, grandparents, and siblings. We categorized children as exposed to bereavement during prenatal life if their mothers lost an elder child, husband or parent during the period from one year before conception to the child’s birth. We identified 45,302 children exposed to maternal bereavement; the remaining children were included in the unexposed cohort. The outcome of interest was diagnosis of type-2 diabetes. We estimated incidence rate ratios (IRRs) from birth using log-linear poisson regression models and used person-years as the offset variable. All models were adjusted for maternal residence, income, education, marital status, sibling order, calendar year, sex, and parents’ history of diabetes at the time of pregnancy. Results We found children exposed to bereavement during their prenatal life were more likely to have a type-2 diabetes diagnosis later in life (aIRR: 1.31, 1.01–1.69). These findings were most pronounced when bereavement was caused by death of an elder child (aIRR: 1.51, 0.94–2.44). Results also indicated the second trimester of pregnancy to be the most sensitive period of bereavement exposure (aIRR:2.08, 1.15–3.76). Conclusions Our data suggests that fetal exposure to maternal bereavement during preconception and the prenatal period may increase the risk for developing type-2 diabetes in childhood and young adulthood.

Improved quality of Type 2 diabetes care following electronic feedback of treatment status to general practitioners: a cluster randomized controlled trial.

Diabet. Med. 28, 325–332 (2011)

Relationship of HbA1c variability, absolute changes in HbA1c, and all-cause mortality in type 2 diabetes: a Danish population-based prospective observational study

Objective We assessed the relationship of mortality with glycated hemoglobin (HbA1c) variability and with absolute change in HbA1c. Design A population-based prospective observational study with a median follow-up time of 6 years. Methods Based on a validated algorithm, 11 205 Danish individuals with type 2 diabetes during 2001–2006 were identified from public data files, with at least three HbA1c measurements: one index measure, one closing measure 22–26 months later, and one measurement in-between. Medium index HbA1c was 7.3%, median age was 63.9 years, and 48% were women. HbA1c variability was defined as the mean absolute residual around the line connecting index value with closing value. Cox proportional hazard models with restricted cubic splines were used, with all-cause mortality as the outcome. Results Variability between 0 and 0.5 HbA1c percentage point was not associated with mortality, but for index HbA1c ≤8% (64 mmol/mol), a variability above 0.5 was associated with increased mortality (HR of 1 HbA1c percentage point variability was 1.3 (95% CI 1.1 to 1.5) for index HbA1c 6.6–7.4%). For index HbA1c≤8%, mortality increased when HbA1c declined, but was stable when HbA1c rose. For index HbA1c>8%, change in HbA1c was associated with mortality, with the lowest mortality for greatest decline (HR=0.9 (95% CI 0.80 to 0.98) for a 2-percentage point decrease). Conclusions For individuals with an index HbA1c below 8%, both high HbA1c variability and a decline in HbA1c were associated with increased mortality. For individuals with index HbA1c above 8%, change in HbA1c was associated with mortality, whereas variability was not.

Something is Amiss in Denmark: A Comparison of Preventable Hospitalisations and Readmissions for Chronic Medical Conditions in the Danish Healthcare System and Kaiser Permanente

BackgroundAs many other European healthcare systems the Danish healthcare system (DHS) has targeted chronic condition care in its reform efforts. Benchmarking is a valuable tool to identify areas for improvement. Prior work indicates that chronic care coordination is poor in the DHS, especially in comparison with care in Kaiser Permanente (KP), an integrated delivery system based in the United States. We investigated population rates of hospitalisation and readmission rates for ambulatory care sensitive, chronic medical conditions in the two systems.MethodsUsing a historical cohort study design, age and gender adjusted population rates of hospitalisations for angina, heart failure, chronic obstructive pulmonary disease, and hypertension, plus rates of 30-day readmission and mortality were investigated for all individuals aged 65+ in the DHS and KP.ResultsDHS had substantially higher rates of hospitalisations, readmissions, and mean lengths of stay per hospitalisation, than KP had. For example, the adjusted angina hospitalisation rates in 2007 for the DHS and KP respectively were 1.01/100 persons (95%CI: 0.98-1.03) vs. 0.11/100 persons (95%CI: 0.10-0.13/100 persons); 21.6% vs. 9.9% readmission within 30 days (OR = 2.53; 95% CI: 1.84-3.47); and mean length of stay was 2.52 vs. 1.80 hospital days. Mortality up through 30 days post-discharge was not consistently different in the two systems.ConclusionsThere are substantial differences between the DHS and KP in the rates of preventable hospitalisations and subsequent readmissions associated with chronic conditions, which suggest much opportunity for improvement within the Danish healthcare system. Reductions in hospitalisations also could improve patient welfare and free considerable resources for use towards preventing disease exacerbations. These conclusions may also apply for similar public systems such as the US Medicare system, the NHS and other systems striving to improve the integration of care for persons with chronic conditions.

HbA1c in an unselected population of 4438 people with Type 2 diabetes in a Danish county

OBJECTIVE To describe the use and level of HbA1c in a large unselected Type 2 diabetic population in Denmark. In addition, to describe the characteristics of the patients and the general practitioners in relation to the monitoring of HbA1c. DESIGN Data were collected from public data files for the period January 1993 to December 1997. SETTING The County of Vejle with a background population of 342,597 citizens, 303,250 of whom were listed with participating general practitioners. PATIENTS The Type 2 diabetic population alive and resident in the county on 1 January 1997. RESULTS In a population of 4438 Type 2 diabetics, 73% had a minimum of one annual HbA1c measurement in 1997. No HbA1c measurement was associated with a long history of diabetes, diet treatment or old age. Poor glycaemic regulation was found in 65% of the Type 2 diabetics in 1997. Poor glycaemic regulation was associated with tablet or insulin treatment, age under 70 years and long history of diabetes. The interpractice variation was huge. CONCLUSION The quality of HbA1c monitoring of Type 2 diabetics needs to be improved. Possibilities for improvement seem to be present.

Quality of type 2 diabetes management in general practice is associated with involvement of general practice nurses

AIMS To assess whether involvement of general practice nurses in type 2 diabetes care in Danish general practice is associated with improved adherence to national guidelines on regular type 2 diabetes monitoring, and with lower HbA1c and cholesterol levels in the type 2 diabetes population. METHODS The study was an observational study soliciting questionnaire data from 193 Danish general practices and register data on 12,960 patients with type 2 diabetes (age range 40-80 years) from a diabetes database and a laboratory database. Clustering was addressed in the analyses. RESULT Practices with well-implemented nurse-led type 2 diabetes consultations and practices with no nurse(s) employed differed according to the mean proportions of patients whose HbA1c was measured (6.4%-points: 95% CI: 1.5 to 11.4), and the mean proportions of patients whose HbA1c was ≥ 8% (-3.7%-points: 95% CI: -6.7 to -0.6). Small non-significant differences were found in the cholesterol analyses. CONCLUSION Compared with practices with no nurse(s) employed, the quality of diabetes management was generally higher in terms of that HbA1c was measured according to the guidelines in a larger proportion of the diabetes population and the proportion of patients with an HbA1c level ≥ 8% was lower in practices with well-implemented nurse-led type 2 diabetes consultations.