Table 1

Episode-level and individual-level criteria for categorising patterns of prescription opioids use, OPERA cohort

Episode-levelIndividual-level
(1) Acute<90 episode days≥1 acute episode and no long-term use (acute-only)
(2) Long-term≥90 episode days≥1 long-term episode, regardless of acute use
 Episodic<90 days’ of drug supply and/or <50% episode intensity≥1 episodic episode and no chronic use
 Chronic≥90 days’ of drug supply and ≥50% episode intensity≥1 chronic episode, regardless of all other types of use
  • Episode intensity=per cent of episode days covered by drug supply. Individual-level criteria apply to patterns of prescription opioids use across study participant follow-up.