Polysubstance use (PSU), particularly opioid-involved and stimulant-involved PSU, is a growing issue in the USA. PSU increases the risk of negative health consequences, including infectious diseases, worsening physical and mental health conditions, and overdose-related deaths. These consequences occur in the context of varying health risk behaviours, substance-related preferences, and treatment engagements among people with PSU. To inform improvements in prevention, harm reduction, and substance use disorder (SUD) treatment, additional research is needed to comprehensively understand the current context and drivers of PSU preferences, motivations, and behaviours.

Herein, we describe the protocol for a prospective cohort study designed to capture detailed patterns, profiles, and trajectories of PSU, with the aim of comprehensively examining the drivers of PSU behaviours and SUD treatment utilisation. Adults (ages 18–75; n=400) who engage in PSU will be recruited from healthcare institutions, an established participant database maintained by an adjacent SUD research team, and online advertisements. Study assessments will capture dynamic patterns, choice preferences, and motivators of PSU via behavioural economic (BE) measures, detailed Timeline Follow-Back (TLFB) interviews, and self-administered surveys. The assessment timeline will include a baseline survey and TLFB interview, weekly TLFB interviews for 4 weeks post-baseline, and follow-up surveys and TLFB interviews at 4-, 8-, and 12-months post-baseline.

The study is funded through the National Institutes of Health Helping to End Addiction Long-term (HEAL) initiative and was approved by the University of Michigan Medical Institutional Review Board. Findings will be disseminated to academic, clinical, and community partners through the Michigan Innovations in Addiction Care through Research and Education programme. Results from this study will inform actionable and practical insights relevant to the delivery of personalised care in the context of PSU.

This study aimed to identify intraoperative and perioperative factors influencing 30-day mortality after cardiac surgery and to develop a risk score (POP-score) for its prediction.

Retrospective cohort study with multivariable regression analysis.

A tertiary care cardiac surgery centre in Austria; data from consecutive patients undergoing cardiac surgery between 2010 and 2020 were analysed.

A total of 8072 patients were included. The cohort was randomly divided into a derivation cohort (75%) and a validation cohort (25%).

The primary outcome measure was 30-day mortality. We analysed associations between intraoperative and perioperative variables and 30-day mortality, assessed via multivariable regression analysis.

Several factors were significantly associated with 30-day mortality, including intraoperative RBC transfusion (OR 3.407 (95% CI 2.124–5.464)), postoperative high-sensitive cardiac troponin T cut-off levels (OR 2.856 (95% CI 1.958 to 4.165)), need for dialysis/haemofiltration (OR 2.958 (95% CI 2.013 to 4.348)) and temporary extracorporeal membrane oxygenation support (OR 5.218 (95% CI 3.329 to 8.179)) (p

The validated POP-score provides an improved tool for predicting 30-day mortality after cardiac surgery by incorporating intraoperative and perioperative factors alongside the EuroSCORE II. Although model performance was evaluated using 7-day peak troponin data, the score can be calculated within the first 72 hours postoperatively in most patients, supporting its clinical applicability for early decision-making, resource allocation and patient counselling. Further research is warranted to assess its clinical utility in diverse populations.

In current clinical practice, breast cancer is treated according to hormone receptor and human epidermal growth receptor 2 expression (HER2) status, which play an important role in disease management and overall prognosis. Trastuzumab deruxtecan (T-DXd) has been studied in multiple global prospective DESTINY-breast trials. Recent marketing authorisation for T-DXd has been granted from Health Canada for HER2-positive breast cancer who have received prior treatment with trastuzumab emtansine, or at least one prior anti-HER2-based regimen in the metastatic setting, or who have received a prior anti-HER2-based regimen in the neoadjuvant or adjuvant setting and developed disease recurrence during or within 6 months of completing neoadjuvant or adjuvant therapy. T-DXd is also indicated for HER2-low unresectable and/or metastatic breast cancer (mBC) patients who have received at least one prior line of chemotherapy in the metastatic setting or developed disease recurrence during or within 6 months of completing adjuvant chemotherapy. However, there is a paucity of evidence assessing T-DXd in the real-world setting. As such, the overarching aim of this study is to generate Canadian real-world evidence on discontinuations and treatment modifications for patients with HER2+ and HER2-low mBC undergoing treatment with T-DXd.

This is a hybrid, longitudinal cohort study design leveraging patient support programme (PSP) secondary data with additional primary data collection to assess study treatment-related outcomes among patients with HER2+ and HER2-low mBC receiving treatment with T-DXd. Mainly, this study will leverage secondary data from the PSP, which will include clinical and demographic characteristics as well as duration, modification and intensity of treatment information for patients while enrolled in the PSP. These data will be supplemented with primary data, which will be collected via a patient questionnaire and include additional self-reported clinical and demographic characteristics not captured within the PSP, including follow-up data on therapies received, treatment discontinuation information after the PSP closure and frequency of CT scans and cardiac monitoring scans.

The study protocol was approved by the Advarra Institutional Review Board on 13 December 2023 (ID: D133HR00037). Findings will be disseminated by publication in peer-reviewed journals, through oral and poster presentations for various audiences, websites and scientific meetings. Written informed consent will be obtained from all patients prior to agreeing to participate in this study.

Participant recruitment for primary data collection began on 22 April 2024 and was completed on 8 October 2024. Primary data collection for follow-up will continue through up to 12 months after the date of the last enrolment.

NCT06386263.