Projection of the burden of type 2 diabetes mellitus in Germany: a demographic modelling approach to estimate the direct medical excess costs from 2010 to 2040

AIM

To model the future costs of Type 2 diabetes in Germany, taking into account demographic changes, disease dynamics and undiagnosed cases.

METHODS

Using a time-discrete Markov model, the prevalence of diabetes (diagnosed/undiagnosed) between 2010 and 2040 was estimated and linked with cost weights. Demographic, epidemiological and economic scenarios were modelled. Inputs to the model included the official population forecasts, prevalence, incidence and mortality rates, proportions of undiagnosed cases, health expenditure and cost ratios of an individual with (diagnosed/undiagnosed) diabetes to an individual without diabetes. The outcomes were the case numbers and associated annual direct medical excess costs of Type 2 diabetes from a societal perspective in 2010€.

RESULTS

In the base case, the case numbers of diabetes will grow from 5 million (2.8 million diagnosed) in 2010 to a maximum of 7.9 million (4.6 million diagnosed) in 2037. From 2010 to 2040, the prevalence rate amonf individuals ≥40 years old will increase from 10.5 to 16.3%. The annual costs of diabetes will increase by 79% from €11.8 billion in 2010 to €21.1 billion in 2040 (€9.5 billion to €17.6 billion for diagnosed cases).

CONCLUSIONS

The projected increase in costs will be attributable to demographic changes and disease dynamics, and will be enhanced by higher per capita costs with advancing age. Better epidemiological and economic data regarding diabetes care in Germany would improve the forecasting accuracy. The method used in the present study can anticipate the effects of alternative policy scenarios and can easily be adapted to other chronic diseases.

Diabetes incidence does not differ between subjects with and without high depressive symptoms--5-year follow-up results of the Heinz Nixdorf Recall Study

AIMS

Cross-sectional studies have consistently reported evidence for an association between diabetes and depressive disorders. However, only limited prospective studies have examined this association, reporting conflicting results. In a population-based cohort study, we compared cumulative incidences of diabetes between participants with and without high depressive symptoms.

METHOD

We analysed the 5-year follow-up data from the German Heinz Nixdorf Recall study of 3547 participants without diabetes at baseline [mean age 58.8 (sd 7.6) years, 47.5% male]. Depressive symptoms were defined using the Centre for Epidemiologic Studies Depression scale (cut point ≥ 17). Diabetes (diagnosed or previously undetected) was identified by self-reported physician-diagnosed diabetes, medication and high blood glucose levels. We estimated 5-year cumulative incidences with 95% confidence intervals and fitted multiple logistic regression models to calculate the odds ratios, adjusted for age, sex, physical activity, smoking, living with or without partner, and educational level.

RESULTS

The cumulative incidence of diabetes was 9.2% (95% CI 6.3-12.8) in participants with high depressive symptoms at baseline and 9.0% (95% CI 8.0-10.0) in participants without these symptoms. The age- and sex-adjusted odds ratio of diabetes in participants with depressive symptoms compared with those without was 1.13 [95% CI 0.77-1.68; fully adjusted 1.11 (95% CI 0.74-1.65)]. These results did not substantially change in several additional sensitivity analyses.

CONCLUSION

Our study did not show a significantly increased risk of developing diabetes in individuals with high depressive symptoms compared with those without high depressive symptoms during a 5-year follow-up period.

Costs of paediatric diabetes care in Germany: current situation and comparison with the year 2000

AIMS

To estimate direct costs of paediatric Type 1 diabetes care and associated factors in Germany for the year 2007 and to compare results with the costs for the year 2000.

METHODS

Our study includes clinical data and charges for any diabetes-related health care service of 14,185 continually treated subjects with paediatric diabetes aged < 20 years [52.5% male, mean age (SD) 12.1 (4.2) years], derived from a nationwide prospective patient documentation system (DPV). Health-care utilization was valued in monetary terms by using inpatient and outpatient medical fees and retail prices (perspective of the statutory health insurance). Associations between average total diabetes-related costs or various single cost categories per patient and age, sex, migration background, diabetes duration, and metabolic control were analysed by multiple regression procedures and by a two-part model for hospitalization costs. Total direct costs in the whole paediatric diabetes population in Germany were estimated. Mean costs per patient as well as total costs in the German paediatric diabetes population in 2007 were compared to 2000 costs (inflated to the year 2007).

RESULTS

Mean direct diabetes-associated costs per subject were €3524 (inter-quartile range: 1831-4743). Main cost categories were hospitalization (32%), glucose self-monitoring (29%), insulin pump therapy (18%), and insulin (15%). Based on the present estimation, the total costs of paediatric diabetes care in Germany exceeded €110 million in 2007. Compared with estimates of the year 2000, average costs per patient had increased by 20% and total costs for German paediatric diabetes care by 47%.

CONCLUSIONS

Direct costs for paediatric Type 1 diabetes care increased between 2000 and 2007, probably partly because of new therapeutic strategies and an increase in diabetes prevalence.

Blood glucose testing and primary prevention of Type 2 diabetes-evaluation of the effect of evidence-based patient information: a randomized controlled trial

AIMS

To compare the effect of our newly developed online evidence-based patient information vs. standard patient information about sub-threshold elevated blood glucose levels and primary prevention of diabetes on informed patient decision making.

METHODS

We invited visitors to the cooperating health insurance company, Techniker Krankenkasse, and the German Diabetes Center websites to take part in a web-based randomized controlled trial. The population after randomization comprised 1120 individuals aged between 40 and 70 years without known diabetes, of whom 558 individuals were randomly assigned to the intervention group receiving evidence-based patient information, and 562 individuals were randomly assigned to the control group receiving standard information from the Internet. The primary endpoint was acquired knowledge of elevated blood glucose level issues and the secondary outcomes were attitude to metabolic testing, intention to undergo metabolic testing, decisional conflict and satisfaction with the information.

RESULTS

Overall, knowledge of elevated glucose level issues and the intention to undergo metabolic testing were high in both groups. Participants who had received evidence-based patient information, however, had significantly higher knowledge scores. The secondary outcomes in the evidence-based patient information subgroup that completed the 2-week follow-up period yielded significantly lower intention to undergo metabolic testing, significantly more critical attitude towards metabolic testing and significantly higher decisional conflict than the control subgroup (n=466). Satisfaction with the information was not significantly different between both groups.

CONCLUSIONS

Evidence-based patient information significantly increased knowledge about elevated glucose levels, but also increased decisional conflict and critical attitude to screening and treatment options. The intention to undergo metabolic screening decreased. Future studies are warranted to assess uptake of metabolic testing and satisfaction with this decision in a broader population of patients with unknown diabetes.

Regional differences in the prevalence of known Type 2 diabetes mellitus in 45-74 years old individuals: results from six population-based studies in Germany (DIAB-CORE Consortium)

AIM

In Germany, regional data on the prevalence of Type 2 diabetes mellitus are lacking for health-care planning and detection of risk factors associated with this disease. We analysed regional variations in the prevalence of Type 2 diabetes and treatment with antidiabetic agents.

METHODS

Data of subjects aged 45-74 years from five regional population-based studies and one nationwide study conducted between 1997 and 2006 were analysed. Information on self-reported diabetes, treatment, and diagnosis of diabetes were compared. Type 2 diabetes prevalence estimates (95% confidence interval) from regional studies were directly standardized to the German population (31 December 2007).

RESULTS

Of the 11,688 participants of the regional studies, 1008 had known Type 2 diabetes, corresponding to a prevalence of 8.6% (8.1-9.1%). For the nationwide study, a prevalence of 8.2% (7.3-9.2%) was estimated. Prevalence was higher in men (9.7%; 8.9-10.4%) than in women (7.6%; 6.9-8.3%). The regional standardized prevalence was highest in the east with 12.0% (10.3-13.7%) and lowest in the south with 5.8% (4.9-6.7%). Among persons with Type 2 diabetes, treatment with oral antidiabetic agents was more frequently reported in the south (56.9%) and less in the northeast (46.0%), whereas treatment with insulin alone was more frequently reported in the northeast (21.6%) than in the south (16.4%).

CONCLUSION

The prevalence of known Type 2 diabetes showed a southwest-to-northeast gradient within Germany, which is in accord with regional differences in the distribution of risk factors for Type 2 diabetes. Furthermore, the treatment with antidiabetic agents showed regional differences.

Frequency and cost of diabetic ketoacidosis in Germany--study in 12,001 paediatric patients

AIMS

Recently, medical expenditures were found to be 2-fold increased in paediatric patients with diabetic ketoacidotic events (DKA) in the U.S., in particular due to hospitalization. Aim of our study was to analyse DKAs and associated costs in Germany, where structured diabetes care including education is available for all patients.

METHODS

For all 12,001 diabetic patients 0-19 years of age (52.6% male, mean age (SD) 12.6 (3.9) years) documented in a German-wide database, all DKAs were assessed, as well as costs for diabetes-related treatment. Associations between costs and DKA were estimated using log-linear models.

RESULTS

457 (3.8%) patients had at least 1 DKA during 2007. Total annual costs for patients without, with 1, or ≥ 2 DKAs were € 3,330 (95%-CI 3,292-3,368), € 6,935 (CI 6,627-7,244), and € 10,728 (CI 9,813-11,644), respectively, with largest differences for hospitalization costs (€ 693, € 4,145, € 8,092). Age-sex-diabetes duration-adjusted cost ratios for patients with 1, or ≥ 2 DKAs compared to patients without DKA were 2.2 (CI 2.1-2.3) and 3.6 (CI 3.1-4.1), respectively.

CONCLUSIONS

In Germany, paediatric diabetic patients with DKA had up to 3.6-fold higher diabetes-related costs compared to those without DKA. This cost excess was higher compared to a U.S. study, however, the proportion of patients with DKA was much lower (3.8% versus 14.9%). The lower frequency of DKA in Germany may be due to a higher access to and utilization of diabetes education. Interventions should reduce DKA and resulting hospital admission in pediatric patients in order to reduce costs and improve quality of life.

[Type 2 diabetes mellitus and depressive symptoms: what is the cause of what? A systematic literature review]

BACKGROUND

Diabetes mellitus type 2 and depressive symptoms are statistically associated. The question is if one of the two diseases is causal for the other.

METHODS

Systematic review using Medline and searching for prospective controlled population based observational studies and meta-analysis in English or German language.

RESULTS

Patients with type 2 diabetes have a higher incidence of depressive symptoms - compared to patients having no diabetes. And patients with depressive symptoms have a higher incidence of type 2 diabetes; however the findings for the first relation are only weak.

DISCUSSION

Knowing about this - even causal - co-morbidity is important in care, including a routine diagnostic approach to find out if the other disease is also present.

Diabetes and Incident Depression: Is the Association Mediated or Modified by Sociodemographic Factors or Co-morbidities? A Systematic Review

Diabetic patients suffer more frequently from depression. Aim was to evaluate sociodemographic parameters and co-morbidities and late complications as potential modifying factors in the occurrence of depression in diabetic individuals.

We performed a systematic review, based on established meta-analyses and additional original publications in 2005–2009 in Medline and PsycINFO. We included articles focusing on longitudinal studies which evaluated the appearance of depression in diabetic and non diabetic individuals and further analyzed interactions or separate additional influences of potential modifying factors.

8 eligible studies were identified. 6 studies were population based. Only 3 studies analyzed the interaction between the variables of interest and diabetes on the incidence of depression. Remaining used diverse other methods to control for associated factors.

The strongest influence was found for a general measure of co-morbidities but this influence was ambiguous. No significant modifying effect or interaction was found for sociodemographic factors.

There seems to be a clear need for more research concerning mediating and modifying factors or a more stringent presentation of results in order to identify groups at risk or to identify treatment strategies.

Diabetes prevalence based on health insurance claims: large differences between companies

AIMS

We investigated if there are substantial differences in the prevalence of diabetes between members of different health insurance funds in Germany and, if so, which variables might explain these differences.

METHODS

Ten representative surveys (conducted between 2004 and 2008) of the Bertelsmann Healthcare Monitor, comprising 15 089 participants aged 18-79 years, were analysed. Our main independent variable was membership in one of eight health insurance funds. We first estimated the crude prevalence of diabetes stratified by these funds. We further fitted logistic regression models and stepwise adjusted for age and sex, further co-morbidities and anthropometric measures and factors influencing health awareness and lifestyle.

RESULTS

The overall prevalence of diabetes was 6.9%. Stratified by health insurance funds, prevalences ranged between 3.9% within the Innungskrankenkassen to 11.4% within the Allgemeine Ortskrankenkassen. Adjusting for age and sex only led to minor changes. After controlling for all mentioned variables, these differences remained. Compared with those who were privately insured, persons within the Allgemeine Ortskrankenkassen (OR 1.73; 95% CI 1.30-2.29), the Betriebskrankenkassen (OR 1.54; 95% CI 1.15-2.07) and the Barmer (OR 1.39; 95% CI 1.01-1.91) had a higher prevalence.

CONCLUSIONS

We found considerable differences in diabetes prevalence between German health insurance funds that remained after controlling for several relevant variables.

[Structural differences between health insurance funds and their impact on health services research: results from the Bertelsmann Health-Care Monitor]

AIM

Claims data of health insurance companies are an important database for health services research. We investigated if there are differences in baseline characteristics and prevalence of chronic diseases between members of several health insurance funds in Germany, and if so, whether adjusting for age and sex could explain these differences.

METHODS

10 representative surveys (conducted between 2004 and 2008) of the 'Bertelsmann Health-Care Monitor' comprising 15 089 participants aged 18 to 79 years were analysed. Our main independent variable was membership in one of 8 health insurance funds. The prevalence of self-reported hypertension, diabetes, atopic diseases, coronary heart disease and heart failure was studied. We first estimated the crude prevalence of chronic diseases stratified by these funds. We further fitted logistic regression models and adjusted for age and sex as well as for further comorbidities and health related factors.

RESULTS

Most respondents were insured in the BKK (Betriebskrankenkassen; 20.1%), the AOK (Allgemeinen Ortskrankenkassen; 19.2%) and private health insurances (15.3%). Substantial differences were found according to age, sex, educational level and prevalences of chronic diseases. Stratified by health insurance funds, prevalences ranged between 17.1-29.6% for hypertension, between 3.9-11.4% for diabetes, between 4.3-6.7% for atopic diseases, between 3.4-6.7% for coronary heart disease and between 2.6-5.7% for heart failure. When adjusting for sex and age, estimates for all 5 diseases were significant higher in AOK members compared to privately insured persons (3 diseases within the BAMER and the DAK, accordingly). In total, this was the case for 17 out of 35 comparisons. Even after adjusting for further comorbidities and health related factors 6 out of 35 comparisons showed significant increased estimates compared to privately insured persons.

CONCLUSION

We found considerable differences in the prevalence of chronic diseases between German health insurance funds that remained after controlling for age and sex, and even after adjustment for further health-related variables. Further methodological studies are urgently needed to assess strengths and weaknesses of German claim data.

Improvement in pregnancy-related outcomes in the offspring of diabetic mothers in Bavaria, Germany, during 1987-2007

AIMS

Reducing the risk of adverse outcomes in diabetic pregnancies to the level of risk in non-diabetic pregnancies is a major goal in diabetes care. So far there have not been any data to show whether progress is being made towards this goal.

METHODS

We used population-based data on 2,292,053 deliveries between 1987 and 2007 in Bavaria, Germany, to assess temporal trends for stillbirths, early neonatal mortality, preterm delivery, macrosomia and malformations in consecutive 7 year intervals. We estimated prevalences and prevalence odds ratios for these outcomes. For stillbirth, as the most severe adverse outcome, we assessed the contributions of several predictors using multiple regression models.

RESULTS

With the exception of early neonatal deaths, the risks for all outcomes were significantly increased in the offspring of mothers with pregestational diabetes in all three time periods (e.g. odds ratio for stillbirths in diabetic compared with non-diabetic mothers in 2001-2007, 1.89; 95% confidence interval 1.24, 2.87). However, the prevalence of stillbirths, premature delivery and macrosomia decreased over time in diabetic mothers (e.g. 1.71% for stillbirths in 1987-1993 and 0.66% in 2001-2007), as did the respective odds ratios. Maternal smoking, hypertension and substandard utilization of antenatal care were significantly associated with stillbirths in diabetic women.

CONCLUSIONS

Although the risk of adverse pregnancy outcomes is still increased in diabetic mothers, considerable improvement has been achieved. We hypothesize that this improvement is possibly due to improved diabetes care.

Reduced incidence of blindness in relation to diabetes mellitus in southern Germany?

AIMS

We estimated the incidence of blindness in the diabetic and non-diabetic population in 2008 and compared it with results from 1990-1998 in a neighbouring region.

METHODS

All newly registered blindness allowance recipients in 2008 were drawn up in a German region (population 4.5 million). We estimated sex-specific, age-specific and standardized incidence rates of blindness in the diabetic and the non-diabetic population and relative and attributable risks as a result of diabetes. A comparison to the data from 1990-1998 was performed using log-linear Poisson regression.

RESULTS

Four-hundred and sixty-eight cases were drawn up (63% female). One-hundred and twenty-two (26.1%) had diabetes. Blindness incidence rates (per 100, 000 person-years) standardized to the 2008 German population were: men 9.1 (95% confidence interval 7.8-10.5), women 9.9 (8.8-11.1); diabetic population: men 21.8 (11.6-31.9), women 19.7 (9.2-30.1); non-diabetic population: men 8.0 (6.6-9.5), women 9.1 (7.9-10.3). Relative risk of blindness, diabetic vs. non-diabetic population: men 2.7 (1.6-4.5), women 2.2 (1.3-3.8). Attributable risk among exposed: 63% in men, 54% in women. Population attributable risk: 12% in men, 8% in women. Incidences of blindness were significantly lower than in all years of the period 1990-1998 in both the diabetic and the non-diabetic population.

CONCLUSIONS

We found the incidence of blindness to be approximately 2.5-fold higher in the diabetic compared with the non-diabetic population. Fifty-eight per cent of the risk to become blind in diabetic individuals and 9% of the risk to become blind in the entire population were attributable to diabetes. The decrease of the blindness incidence observed during the 1990s may have continued.

[Memorandum III: Methods for Health Services Research (Part 2)]

The methodical quality of health services research studies is often subject to criticism. Common standards in the field of health services research have been lacking so far. Hence, the German Network for Health Services Research [Deutsches Netzwerk Versorgungsforschung e. V. (DNVF e. V.)] decided to contribute to an improvement of this situation. The DNVF e. V. has already published part 1 of the Memorandum III"Methods for Health Services Research" for the 3 subject areas "Epidemiological Methods for Health Services Research", "Methods for Organisational Health Services Research" and "Methods for Quality of Life Research". The herewith published Part 2 of the Memorandum extends the spectrum by describing the methodological principles and minimum standards of "Methods of Health Economic Evaluations" and "Registries for Health Services Research". On 30 (th) August 2010, the member societies, mentioned as authors, approved this second part of the Memorandum III. 2 in-depth publications focussing on the 2 mentioned topics will be published in the next issues of this journal. This memorandum is intended for health services researchers who are planning, conducting and publishing studies as well as for reviewers who evaluate research proposals and publications on health services research studies. In accord with the expected advances in knowledge in health services research, it is planned to update the 2 parts of Memorandum III at appropriate intervals and to publish further parts from the huge spectrum of methods relevant to this field in the near future. Thus, the Memorandum has to be considered as work in progress.

[Methods of health economic evaluation for health services research]

On August 30, 2010, the German Network for Health Services Research [Deutsches Netzwerk Versorgungsforschung e. V. (DNVF e. V.)] approved the Memorandum III "Methods for Health Services Research", supported by the member societies mentioned as authors and published in this Journal [Gesundheitswesen 2010; 72: 739-748]. The present paper focuses on methodological issues of economic evaluation of health care technologies. It complements the Memorandum III "Methods for Health Services Research", part 2. First, general methodological principles of the economic evaluations of health care technologies are outlined. In order to adequately reflect costs and outcomes of health care interventions in the routine health care, data from different sources are required (e. g., comparative efficacy or effectiveness studies, registers, administrative data, etc.). Therefore, various data sources, which might be used for economic evaluations, are presented, and their strengths and limitations are stated. Finally, the need for methodological advancement with regard to data collection and analysis and issues pertaining to communication and dissemination of results of health economic evaluations are discussed.