Table 1.

Design decisions for OUD Cascade of care framework construction.

Design element	Recommended when feasible	Complicates interpretation	Implications for intended use
Scope	Choose a breadth and depth that is feasible based on data availability and window of observation and yet tailored to satisfy specific reporting requirements or answer critical questions	Using all data in an exploratory fashion with no hypotheses or questions in mind.	Greater breadth/width may require more clinical services data across additional care settings. Depth may additionally allow for the inclusion of more patient characteristics to study demographics and comorbidity among vulnerable populations and associations with progression through stages.
Window of Observation	Longitudinal	Cross-Sectional	Longitudinal CoCs*, whether prospective or retrospective, avoid the synthetic cohort assumption by following the same individuals over time as they go through the CoC, whereas cross-sectional designs require more assumptions and are thus more prone to biases
Population	Single	Multiple	Data limitations or shortages of staff effort for more rigorous analyses may lead to multiple population studies but limitations in their interpretation should be made explicit for readers.
Denominator-Numerator Linkage	Linked	Unlinked (typically a multiple populations design)	Unlinked designs may be helpful for monitoring broad trends in service delivery at the population level but cannot reflect the longitudinal outcomes of the same sample and may obscure barriers for successful progression across stages
Denominator-Denominator Linkage	Linked (by definition a single population design)	Unlinked	Especially if unlinked, researchers and policymakers must be very clear in publishing and describing methodology and results to avoid misinterpretation of findings

^*CoC = Cascade of Care; OUD = opioid use disorder.