Definition

The indicator Medication is defined as the proportion of persons with known type 2 diabetes currently receiving one of the following forms of medication:

1. No medication
2. Metformin monotherapy
3. Other oral antidiabetic agents (apart from metformin monotherapy)
4. Only insulin
5. Insulin and oral antidiabetic agents, including metformin

Operationalisation

The Medication indicator relies on self-reported data from people with known type 2 diabetes about their use of medication over the last seven days.

• ‘Have you taken any medication or supplements such as vitamins or minerals in the past seven days? Please also include pain relievers, insulin supplements, medications received from your doctor, injections and herbal medicines. Please also provide information about preparations bought in supermarkets or chemists.’
  

• Details on medicines that were taken by the participants over the last seven days were confirmed by data collected through automatic medication capturing. This capture using ‘AmEDa’ medication capturing database included ATC codes and indications of the medication taken.
  
  Antidiabetic medication taken by people with known type 2 diabetes was identified using the following ATC codes:

  • Metformin monotherapy – ATC code A10BA02
  • Insulin – ATC code A10A
  • Oral anti-diabetic medication – ATC code A10B

In order to focus on known type 2 diabetes, those who may have type 1 diabetes were identified and excluded from among participants with known diabetes using an algorithm (age at diabetes diagnosis <30 years AND insulin treatment immediately after diagnosis AND current insulin treatment).

Reference population

Resident population in Germany with known type 2 diabetes, aged 45 to 79 years

Data source

Nationwide RKI interview and examination surveys 1997-1999 (GNHIES98) and 2008-2011 (DEGS1) based on a population registry sample and self-completed questionnaire, medical interview, automated medicine registration and examination.

Number of cases

• GNHIES98: n = 7,124
• DEGS1: n = 7,115 (of which n = 2,923 had also participated in GNHIES98)

For the indicator Type 2 diabetes medication, data from the 45-to-79 age group with known type 2 diabetes are evaluated:

• GNHIES98: n = 333
• DEGS1: n = 526

Calculation

• Description: For the indicator, the figures for total, women and men are provided and are stratified by age group, residential area and education as far as the number of cases available for the figure is ≥ 5 and the statistical uncertainty in the estimate of the indicator is not considered too large (a coefficient variation ≤ 33.5%).
• Stratification: The geographical classification of the residence of the participating person was carried out by east and west (east = former East Germany, including all of Berlin; west = former West Germany, not including West Berlin). Educational status was determined using the CASMIN index, which takes information on both school and vocational training into account and allows a categorisation into a low, medium and high education group.
• Weighting: In order to correct for deviations from the underlying reference population due to different participation rates or sampling probabilities, weighting factors were used when calculating the indicator. These adjust the surveys to the population structure of the reference population with regard to sex, age, federal state, German citizenship (yes / no), community type and education as of 31 December 1997 (GNHIES98) and 31 December 2010 (DEGS1). In DEGS1, the different participation probability of re-participants from GNHIES98 was also taken into account in the weighting.
• Age standardization: Age standardization and trend weighting was carried out by calculating the weighting factor in GNHIES98 using the age, sex and federal state structure of the reference population as of 31 December 2010.

Data quality

RKI interview and examination surveys provide representative results for the 18- to 79-year-old resident population of Germany. The population aged 80 years and over will only be included in future survey waves. As is the case in all population-based studies, underrepresentation of the seriously ill and those living in institutions must be assumed.