The ‘time-limited trial’ for patients with critical illness is a collaborative plan made by clinicians, patients and families to use life-sustaining therapies for a defined duration. After this period, the patient’s response to therapy informs decisions about continuing recovery-focused care or transitioning to comfort-focused care. The promise of time-limited trials to help navigate the uncertain limits and benefits of life-sustaining therapies has been extensively discussed in the palliative and critical care literature, leading to their dissemination into clinical practice. However, we have little evidence to guide clinicians in how to conduct time-limited trials, leading to substantial variation in how and why they are currently used. The overall purpose of this study is to characterise the features of an optimal time-limited trial through a rich understanding of how they are currently shaping critical care delivery.

We are conducting an observational, multicentre, focused ethnography of time-limited trials in patients with acute respiratory failure receiving invasive mechanical ventilation in six intensive care units (ICUs) within five hospitals across the US. Study participants include patients, their surrogate decision makers and ICU clinicians. We are pursuing two complementary analyses of this rich data set using the open-ended, inductive approach of constructivist grounded theory and, in parallel, the structured, deductive methods of systems engineering. This cross-disciplinary, tailored approach intentionally preserves the tension between time-limited trials’ conceptual formulation and their heterogeneous, real-world use.

This study has been reviewed and approved by the University of Wisconsin Institutional Review Board (IRB) as the single IRB (ID: 2022-1681; initial approval date 23 January 2023). Our findings will be disseminated through peer-reviewed publication, conference presentations, and summaries for the public.

NCT06042621.

Opioid agonist treatment (OAT) prescribing patterns have shifted in recent years in British Columbia (BC), Canada due to the increasingly toxic unregulated drug supply. Experimental evidence to support guidelines on the effectiveness of maintaining clients at different maintenance dosage levels is incomplete and outdated for the fentanyl era. Our objective is to assess the risk of treatment discontinuation and mortality among individuals receiving different maintenance dosage strategies for OAT with methadone, buprenorphine/naloxone or slow-release oral morphine (SROM) at the population level in BC, Canada.

We propose a retrospective population-level study of BC residents initiating OAT on methadone, buprenorphine/naloxone or SROM between 1 January 2010 and 31 December 2022 who were ≥18 years of age with no known pregnancy, no history of cancer diagnosis or receiving palliative care and not currently incarcerated. Our study will employ health administrative databases linked at the individual level to emulate a target trial per OAT type where individuals will be assigned to discrete maintenance dosing strategies, according to the full range observed in BC during the study period. Primary outcomes include treatment discontinuation and all-cause mortality. To determine the effectiveness of alternative maintenance doses, we will emulate a ‘per-protocol’ trial using a clone-censor-weight approach to adjust for measured time-dependent confounding by indication.

The protocol, cohort creation and analysis plan have been classified and approved as a quality improvement initiative by Providence Health Care Research Ethics Board and the Simon Fraser University Office of Research Ethics. All data are deidentified, securely stored and accessed in accordance with provincial privacy regulations. Results will be disseminated and shared with local advocacy groups and decision-makers, developers of national and international clinical guidelines, presented at national and international conferences and published in peer-reviewed journals electronically and in print.