"The estimate on the number of drug abusers is associated with some uncertainty. The estimate is dependent, in one respect, on the definition of a drug abuser, and in another, on which methods and data material the estimate is based.
"As in previous years, the estimate made in 2010 was made using the capture-recapture model4. The estimate is carried out based on the National Patient Register (LPR) and the national register of drug abusers who are receiving or have received treatment (SIB). The approach has been to investigate how many persons are registered in the LPR with a drug-related diagnosis5. An analysis is then carried out of how many of these people are also listed in the SIB.
"The estimate on the number of drug abusers from 1996 to 2009 appears in table 4.2.1. Since the calculations of the estimates throughout the years are based on the 'live' registers, an adjustment in the estimates from previous years has also been made in
connection with the preparation of the 2010 estimate.
"The estimate does not include experimental drug use, but estimates the number of people who have a more constant us of drugs, as a result of which they suffer harmful physical, mental and/or social effects. Drug abusers in substitution treatment have been included in the estimate.
"The estimate is statistically uncertain (confidence interval). However, even when including this uncertainty, there is a clear increase in the number of drug abusers from 2001 to 2009. The number of drug abusers in 2009 is estimated to be 33,000, of which 10,900 are estimated to be cannabis abusers. In 2005 the number of cannabis abusers was 7,900.
"In recent years, the 'population' of drug users receiving treatment, which is one of figures used for calculating the estimate, has changed (the treatment population is described in the next section). There seems to be an actual, relative decrease in the number of drug users seeking treatment for opioids/heroin addiction, while there are an increasing number of users seeking treatment for addiction to cannabis and stimulants. The change is particularly seen among the 'new' individuals in drug treatment and is assumed to reflect the similar changes in the population of drug abusers."
Sundhedsstyrelsen (National Board of Health), "2012 National Report (2011 data) to the EMCDDA by the Reitox National Focal Point: Denmark: New Development, Trends and in-depth information on selected issues," (Copenhagen, Denmark: Sundhedsstyrelsen, Nov. 2012), pp. 30-31.