Determinants of prescription opioid use: population-based evidence from Finland.

Abstract

Previous studies have shown that prescription opioid use is more common in socio-economically disadvantaged communities in the United States. This study examined the area and individual-level determinants of prescription opioid use in Finland during the period 1995-2016. Logistic regression analysis using nation-wide data on filled opioid-related prescriptions dispensed at Finnish pharmacies and covered by National Health Insurance. Opioid consumption was linked, using personal identification codes, to population-based data maintained by Statistics Finland, which records individual background and area-level characteristics. Working-age population aged between 15 and 64years in Finland during the periods 1995-2007 (n=4 315 409) and 2009-16 (n=4 116 992). Annual prescription opioid use was measured using defined daily doses (DDD) and whether people used opioids during a year. Prescription opioid use increased in Finland from 1995 to 2016 (from less than 1 to 7%), but the increase was explained by the change in the treatment of codeine-based opioids in National Health Insurance. The area-level unemployment rate was positively correlated with the share of opioid users at the municipal level (r=0.36; P<0.001). In comparison with being employed, being outside the labour force was associated with increased opioid use in 1995-2007 [odds ratio (OR)=2.22, 95% confidence interval (CI)=2.10-2.36] and non-codeine opioid use in 2009-16 (OR=2.16, 95% CI=2.06-2.27), but not with codeine opioid use in 2009-16. Prescription opioid use in Finland appears to be more common among low socio-economic status people, similar to the United States and the United Kingdom.