The GDS sample
Don’t look to GDS for national estimates. GDS is designed to answer comparison questions that are not dependent on probability samples. The GDS database is huge, but its non-probability sample means analyses are best suited to highlight differences among user populations. GDS recruits younger, more experienced drug using populations. We spot emerging drugs trends before they enter into the general population.
Open access papers describing our sample and recruitment strategies can be found here and here.
Overall respondent characteristics from GDS
As our survey is online the GDS sample is biased towards those with easy access to the internet and who have higher levels of health literacy than the general population. Although there are some marked variations in the core demographics between participating countries, as a broad overview the following describes the overall makeup of the annual GDS samples:
- ratio of male to female respondents is 2:1
- mean age of the sample is around 25 years
- 85% heterosexual
- 90% white
- 60% have a university degree or higher
- 70% have used an illicit drug in the last year
- 4% have ever injected any drug
- >50% report regular involvement in nightlife and clubbing
GDS surveys – annual participation, data collection period, country partners and translated languages
| GDS2012 | GDS2013 | GDS2014 | GDS2015 | GDS2016 | |
|---|---|---|---|---|---|
| Data collection period | Nov–Dec 2011 | Nov–Dec 2012 | Nov–Dec 2013 | Nov–Dec 2014 | Nov 2015–Jan 2016* |
| Participant numbers | 15,000 | 22,000 | 78,000 | 100,000+ | 100,000+ |
| Languages | English | English | English | English | English |
| Danish | Danish | Danish | |||
| Flemish | Flemish | Flemish | |||
| French | French | French | |||
| German | German | German | |||
| Hungarian | Greek | Greek | |||
| Portuguese | Hungarian | Hungarian | |||
| Portuguese (SA) | Italian | Italian | |||
| Spanish | Portuguese | Portuguese | |||
| Spanish (SA) | Portuguese (SA) | Portuguese (SA) | |||
| Slovenian | Spanish | Spanish | |||
| Spanish (SA) | Spanish (SA) | ||||
| Country partners | UK | Australia | Australia | Australia | Australia |
| UK | Belgium | Belgium | Belgium | ||
| USA | Denmark | Denmark | Colombia | ||
| France | France | Denmark | |||
| Germany | Germany | France | |||
| Hungary | Greece | Germany | |||
| Ireland | Hungary | Greece | |||
| Mexico | Ireland | Hungary | |||
| Netherlands | Mexico | Ireland | |||
| New Zealand | Netherlands | Mexico | |||
| Portugal | New Zealand | New Zealand | |||
| Slovenia | Poland | Netherlands | |||
| Spain | Portugal | Norway | |||
| Switzerland | Slovenia | Poland | |||
| Spain | Portugal | ||||
| UK | Switzerland | Slovenia | |||
| Spain | |||||
| USA | UK | Switzerland | |||
| USA | UK | ||||
| USA |
* The unfortunate event of the Paris bombings in 2016 interrupted our media partner involvement for a period of 3 weeks in the middle of GDS’s peak data collection period in November 2015, so we extended the survey for 4 weeks into January 2016
Breakdown by country of total participation across the last 3 surveys, GDS2014, GDS2015 and GDS2016 combined
| Country | Approximate n (to nearest 1,000) |
|---|---|
| Germany | 85,000 |
| UK | 20,000 |
| Switzerland | 19,000 |
| USA | 17,000 |
| Australia | 15,000 |
| New Zealand | 15,000 |
| France | 14,000 |
| Netherlands | 13,000 |
| Hungary | 10,000 |
| Brazil | 6,000 |
| Belgium | 5,000 |
| Spain | 5,000 |
| Republic of Ireland | 4,000 |
| Austria | 4,000 |
| Italy | 4,000 |
| Portugal | 3,000 |
| Canada | 3,000 |
| Columbia | 3,000 |
| Denmark | 3,000 |
| Norway | 2,000 |
| Sweden | 2,000 |
| Others across region | 15,000 |
Is there a country you are interested in that isn’t listed above, or you would like your country to join GDS? Email us: info@globaldrugsurvey