Oxycodone and Morphine use in hospitals and primary healthcare in Norway 2010-2021

Background:
The use of opioids has increasingly been problematized, with a particular focus on oxycodone. 90% of all opioids in Norway are prescribed in primary healthcare (PHC). PHC decisions are of great importance if one wishes to influence overall opioid prescribing. Hospital prescriptions can influence PHC prescribing in three ways; continuation of hospital-initiated medications, patient requests based on prior hospital medications, and GPs interpreting hospital prescriptions as informal guidelines.
Materials and Methods:
Morphine and oxycodone, practical in all settings, served as opioid proxies to compare covariation between hospitals and their catchment areas. We analyzed 2010-2021 procurement data from Pharmacy Statistics of Hospital Pharmacies and PHC dispensing data from the Norwegian Prescription Database, including all 18 health trusts, calculating Pearson's r from morphine-oxycodone prescription ratios and geographic disparities. We obtained yearly tender agreements from the national Hospital Procurement Organization. 
Results:
Hospitals increased their use of oxycodone by 67% and morphine by 12.6% from 2010 to 2021. In PHC, oxycodone use increased by 86.6%, whereas morphine use decreased by 23.2%. 15 of 18 health trusts increased their relative prescribing of oxycodone. There is a moderate covariation between each health trust and its respective catchment area's changes in prescription practices with a Pearson r of 0.5. In the same period, the number of tender agreements in hospitals for oxycodone decreased by -4.7% and for morphine by -86.7%.
Conclusion:Our findings reveal a marked shift towards oxycodone use over morphine in Norwegian hospitals and PHC. This, coupled with the covariation between hospital and PHC prescribing patterns, underscores two main takeaways: 1) Hospital prescribing must be considered if one wants to change prescription practices in PHC 2) there is a need for a closer examination of the tender agreement system and its influence on medical decision-making.