Sex and age differences among tramadol users in three Nordic countries.

INTRODUCTION: The aim of this study was to examine the prevalence and characteristics of tramadol users in Denmark, Norway and Sweden. METHODS: Data from the national prescription databases comprising the entire population of Denmark, Norway and Sweden between 2007 and 2015 were used to assess prescription medicine use and sold amount (in defined daily doses (DDDs)) of tramadol, other opioids and non-steroidal anti-inflammatory drugs. RESULTS: From 2007 to 2015 the prevalence of tramadol users increased in Denmark from 45 to 52 per 1,000 residents, and in Norway from 20 to 41 per 1,000 residents. In Sweden, the prevalence decreased from 36 to 17 per 1,000 residents. In comparison, the prevalence of other opioid users decreased in Denmark and Norway, but increased in Sweden. During the study period, there were more female than male tramadol users in all three countries, and the prevalence of tramadol users tended to increase with age. The average tramadol DDD per treated patient remained fairly constant in Norway, while it increased in Denmark and Sweden. In Denmark and Norway, women received a higher DDD than men. The amount of sold tramadol and other opioids combined per 1,000 residents was highest in Denmark. CONCLUSIONS: From 2007 to 2015, the prescription patterns of tramadol and other opioids differed between the three countries. Tramadol was generally used more frequently by women. Women received higher DDD then men in Norway and Denmark, but not in Sweden. The prevalence of tramadol users tended to increase with age in all countries. FUNDING: none. TRIAL REGISTRATION: not relevant.