Definition

The Sugar-sweetened beverage indicator is defined as the proportion of people in the population who consume sugar-sweetened beverages daily.

Operationalisation

The consumption of sugar-sweetened beverages is assessed using self-reported data collected using a food frequency questionnaire:

• GNHIES98: ‘How often do you drink the following beverages? Please think about the past 12 months.’
  Soft drinks (fizzy drinks, fruit juice, effervescent drinks, cola, tonic water):

  • Several times a day
  • Daily or almost daily
  • Several times a week
  • About once a week
  • Two to three times a month
  • Once a month or less
  • (Almost) never

• DEGS1: ‘How often during the past four weeks have you drunk sugar-sweetened beverages (such as cola, fizzy drinks, iced tea, malt beer or energy drinks)? This does not include diet beverages.’

  • Never
  • Once per month
  • 2-3 times per month
  • 1-2 times per week
  • 3-4 times per week
  • 5-6 times per week
  • Once per day
  • 2 times per day
  • 3 times per day
  • 4-5 times per day
  • More than 5 times per day

Reference population

Resident population in Germany, aged 18 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)

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 region (north-east, north-west, middle-east, middle-west and south). 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.