Prevalence, incidence and concomitant co-morbidities of type 2 diabetes mellitus in South Western Germany--a retrospective cohort and case control study in claims data of a large statutory health insurance

Abstract

Background: Type 2 diabetes mellitus (T2DM) has become a world-wide epidemic. This chronic metabolic disease has a major impact on life expectancy and on quality of life. The burden of this disease includes a number of co-morbidities. However, estimates of prevalence, incidence and associated diseases as well as the current temporal development and regional differences are largely missing for South Western Germany.

Methods: Lifetime diagnosis-based prevalence, incidence and presence of concomitant co-morbidities were examined between the years 2007 and 2010 in the claims data set of all insured persons of the AOK Baden-Wuerttemberg, a large statutory health insurance. The analysis was based on the respective WHO-ICD-10 codes. Data were standardized for age and sex on the residential population of about 10 million inhabitants of South Western Germany.

Results: The total study cohort involved approximately 3.5 million persons each year. The standardized diagnosis-based prevalence (SDP) of T2DM rose from 6.6%, 7.4%, 8.0%, up to 8.6% in the years 2007 to 2010. Yearly SDP was between 14.0% and 18.9% at an age range of 60 to 64 years and between 26.7% and 31.8% at an age of 75 years or older. In the year 2010 the regional distributions of standardized diagnosis-based prevalence were between 7.6% and 11.6 %, respectively. Incidence rates were 8.3 in 2008, 7.8 in 2009, and 8.7 in 2010 (all rates per 1000). The excess disease risk (odds ratio) of T2DM was for adiposity 2.8 to 3.0, hypertension 2.4 to 3.7, coronary heart disease 1.8 to 1.9, stroke 1.7 to 1.8, renal insufficiency 2.8 to 3.4, and retinopathy 2.8 to 2.9 in the years 2007 to 2010. These co-morbidities appeared several years earlier compared to the non-diabetic population.

Conclusions: T2DM is common and increasing in South Western Germany. In particular a quarter of the population in higher ages was afflicted by T2DM. Interestingly a region-specific pattern was observed as well as an increase in numbers during earlier years in life. Our data underline the need for diabetes awareness programmes including early diagnosis measures as well as structured and timely health surveys for major diseases such as T2DM and its concomitant co-morbidities.

Fig. 1

Lifetime diagnosis-based prevalence of type 2 diabetes mellitus for the years 2007 to 2010. Only persons of the AOK Baden-Wuerttemberg insured all four quarters of a year were analyzed and the results standardized for age and sex on the total residual population of South Western Germany. (***p-value of trend test <0.001)

Fig. 2

Treatment prevalence (a) and incidence (b) of type 2 diabetes mellitus of 5 years age groups. The age group specific diagnosis-based prevalence and incidence rates of insured persons of the AOK Baden-Wuerttemberg are shown for the years 2007 to 2010. Changes from 2007 to 2010 (prevalence) and 2008 to 2010 (incidence) were statistically significant different in all age groups (all p-values < 0.001)

Fig. 3

Lifetime diagnosis-based prevalence of concomitant co-morbidities for the years 2007 to 2010. The rates of insured of the AOK Baden-Wuerttemberg were stratified in persons without type 2 diabetes mellitus (T2DM) and with T2DM and standardized for age and sex on the total residual population of South Western Germany of the respective year

Fig. 4

Comparison of the prevalence rates of concomitant co-morbidities. The age shifts of prevalence rates in persons with and without type 2 diabetes mellitus in the AOK Baden-Wuerttemberg determined at the semi-maximum values are shown for adiposity (a) and several concomitant co-morbidities (b-f) for the year 2010. The horizontal lines show the semi-maximum diagnosis-based prevalence and the vertical lines the respective age belonging to the semi-maximum values. For this analysis the age groups of 20 years and older were considered only

Fig. 5

Regional lifetime diagnosis-based prevalence. The regional variation in the diagnosis-based prevalence of type 2 diabetes mellitus is shown for the year 2010 after standardization on the residual population of the respective distinct districts (a, c, e) or on South Western Germany (b, d, f)