Analgesic Prescribing Trends of Opioids, Nonsteroidal Anti-Inflammatory Drugs, and Paracetamol in Taiwan (2001-2020): Age-Period-Cohort Cross-Sectional Study.

BACKGROUND

Despite ongoing global changes in analgesic prescribing practices, long-term trends accounting for age, period, and cohort effects remain poorly understood in Asian populations, where opioid and nonopioid prescribing trajectories differ from those observed in Western nations.

OBJECTIVE

This study aimed to examine the long-term prescribing trends of opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), and paracetamol in Taiwan by age, calendar period, and birth cohort using an age-period-cohort (APC) framework.

METHODS

We conducted a population-based repeated cross-sectional study using Taiwan National Health Insurance claims data (2001-2020). The cohort included all insured individuals aged 1 to 85 years, with an annual population size of 22.3 to 23.1 million. Exposure variables were structured for APC modeling, comprising 5-year age groups, four 5-year calendar periods (2001-2020), and 5-year birth cohorts (1920-1924 to 2015-2019).

RESULTS

Opioid prescribing prevalence escalated from 123.66 per 100,000 persons in 2001 to 2005 to 706.93 in 2016 to 2020. APC analysis showed a significant positive net drift for opioids (+10.93% per year, 95% CI 10.36%-11.51%; P<.001). The estimated magnitude of the opioid prescribing increase was sensitive to the prescription frequency threshold used. In contrast, paracetamol and NSAIDs showed overall declines (net drifts: -2.44%, 95% CI -2.58% to -2.29%, and -0.82%, 95% CI -0.97% to -0.66%, respectively). Notably, local drifts revealed a significant increase in NSAID prescribing only among adolescents aged 11 to 15 years (+0.80% per year, 95% CI 0.34%-1.27%). Generational analysis suggested higher opioid prescribing risk among younger cohorts (rate ratios 3.06 for the 2015-2019 cohort), although the increase relative to the 2000 to 2004 reference cohort was not statistically significant.

CONCLUSIONS

Reimbursed analgesic prescribing in Taiwan has diverged across drug classes, with a consistent increase in opioid prescribing across all ages and a shift toward NSAID prescribing in younger populations. These claims-based trends should be interpreted as reimbursed prescribing rather than total analgesic use. These findings may inform targeted pharmacovigilance and policies to ensure appropriate pain management while mitigating potential opioid-related risks.