Understanding the first prescription: clinical and demographic drivers of strong opioid use in primary care

Aim: To evaluate the demographic and clinical factors that influence the initiation of weak versus strong opioids among opioid-naïve patients in Australian primary care settings. Methods: This retrospective cohort study focused on opioid-naïve patients, defined as those receiving an eligible opioid prescription with no prior opioid prescriptions in the prior year. The study used general practice data extracted in partnership with Primary Health Networks via the POpulation Level Analysis and Reporting (POLAR) platform. Opioid prescriptions at the time of initiation were categorized as weak or strong. We used multivariate probit model analysis to identify the demographic and clinical factors associated with type of opioid at initiation of prescribing. Results: We identified 415 098 opioid-naïve patients in primary care between January 1, 2018, and July 31, 2023, with 17% initiated on strong opioids. The probability of initiation with a strong opioid increased in patients who were more than 80years of age by 25.0% (95% CI: 0.244 to 0.257) compared with patients who were 20–29 years of age. Patients with diagnoses of pain related to injury procedures (9.7% increase; 95% CI: 0.093 to 0.101) or with prior antipsychotic prescriptions (6.2% increase; 95% CI: 0.055 to 0.067) had higher probabilities of being prescribed strong opioids at initiation than did those without these conditions. Conclusion: One in 6 patients initiated on opioids in primary care was prescribed a strong opioid. This study highlights key factors associated with initiation of strong opioids among opioid-naïve patients. Further assessment of clinical suitability and outcomes associated with strong opioid prescribing can inform our understanding of opioid use in primary care.