Long-term forecasting and evaluation of medicine consumption for the ATC class H with a focus on thyroid hormones in OECD countries using ARIMA models

Abstract

Thyroid hormones are among the most prescribed medicines. In many countries, there are shortages combined with evidence of overuse and irrational prescribing. An analysis was conducted for ATC class H with a focus on thyroid hormones for OECD countries. This study aims to evaluate prescribing behaviours, forecast long-term developments and promote rational prescribing behaviour. The ARIMA(2,1,2) (autoregressive integrated moving average) model successfully predicted the future for 30 OECD countries and the non-OECD country Croatia until 2040. An upward trend is forecast for 18 countries, including Austria (+ 5.7%), Chile (+ 220.0%), Czechia (+ 52.8%), Denmark (+ 15.6%), Estonia (+ 87.8%), Greece (+ 238.7%), Hungary (+ 5.7%), Iceland (+ 18.6%), Italy (+ 42.9%), Latvia (+ 83.7%), Lithuania (+ 131.2%), Portugal (+ 106.7%), Slovakia (+ 182.1%), Slovenia (+ 57.4%), Spain (+ 162.8%), Turkey (+ 168.7%), the United Kingdom (+ 138.1%) and Croatia (+ 190.6%). A downward trend is forecast for 13 countries, including Australia (-3.4%), Belgium (-38.8%), Canada (-95.1%), Costa Rica (-79.5%), Finland (-14.7%), France (-100.0%), Germany (-16.4%), Israel (-21.6%), Korea (-100.0%), Luxembourg (-100.0%), the Netherlands (-35.9%), Norway (-23.6%) and Sweden (-43.6%). The reliability and accuracy of the forecasts varies, being influenced by data quality. While a downward trend is favoured, an upward trend is seen as problematic. Increasing trends predominate in Southern and Eastern Europe and Latin America, while decreasing trends predominate in Northern and Western Europe and the Asia–Pacific Region. Some external factors affect all countries, like an increasing prevalence of thyroid disease. There is evidence of cultural influences on prescribing behaviour. While there is evidence of inappropriate use in countries where prescriptions are predicted to increase, measures to restrict the use of thyroid hormones are more common in countries with a recently reported and predicted declining trend.