The basic pharmacoepidemiology of benzodiazepine use in Norway 2004-9
The aim of this study was to describe these basic pharmacoepidemiological parameters of benzodiazepine use.
Benzodiazepines are effective and safe drugs for treatment of insomnia, anxiety, epilepsy and muscle spasm, but there is also a potential for harmful use, abuse and addiction. Even though these drugs are used extensively, have been on the market for 50 years, and quite a few reports have been published on risk factors and patterns of use, the basic epidemiological parameters of use, such as incidence, prevalence, mean volume used and duration of use have not been documented in Norway.
Data were drawn from the Norwegian prescription database with an observation period of 5 years and 10 months between January 2004 and October 2009.
Around 61 per 1000 Norwegians filled at least one prescription each year in the observation period. The annual incidence rate of new users was 15 per 1000 in 2007, falling to 12 per 1000 in 2009. Of the users of benzodiazepines 65% were female, and they used a lower mean volume than men did. The mean volume used was often very low and for the most part was quite stable. The average length of use was estimated to be between 9 and 15 years. In addition to fewer incident users, the mean volume used also seemed to be declining.
Most benzodiazepine use in Norway lasted a short period or at a very low level. Some individuals, however, carried on using benzodiazepines for years