Radical prostatectomy versus external beam radiation therapy for high-grade, clinically localized prostate cancer: Emulation of a target clinical trial

Reporting of Observational Studies Explicitly Aiming to Emulate Randomized Trials: A Systematic Review

Importance

Observational (nonexperimental) studies that aim to emulate a randomized trial (ie, the target trial) are increasingly informing medical and policy decision-making, but it is unclear how these studies are reported in the literature. Consistent reporting is essential for quality appraisal, evidence synthesis, and translation of evidence to policy and practice.

Objective

To assess the reporting of observational studies that explicitly aimed to emulate a target trial.

Evidence Review

We searched Medline, Embase, PsycINFO, and Web of Science for observational studies published between March 2012 and October 2022 that explicitly aimed to emulate a target trial of a health or medical intervention. Two reviewers double-screened and -extracted data on study characteristics, key predefined components of the target trial protocol and its emulation (eligibility criteria, treatment strategies, treatment assignment, outcome[s], follow-up, causal contrast[s], and analysis plan), and other items related to the target trial emulation.

Findings

A total of 200 studies that explicitly aimed to emulate a target trial were included. These studies included 26 subfields of medicine, and 168 (84%) were published from January 2020 to October 2022. The aim to emulate a target trial was explicit in 70 study titles (35%). Forty-three studies (22%) reported use of a published reporting guideline (eg, Strengthening the Reporting of Observational Studies in Epidemiology). Eighty-five studies (43%) did not describe all key items of how the target trial was emulated and 113 (57%) did not describe the protocol of the target trial and its emulation.

Conclusion and Relevance

In this systematic review of 200 studies that explicitly aimed to emulate a target trial, reporting of how the target trial was emulated was inconsistent. A reporting guideline for studies explicitly aiming to emulate a target trial may improve the reporting of the target trial protocols and other aspects of these emulation attempts.

Characteristics of prostate cancer patients captured by facility-based versus geography-based cancer registries

PURPOSE

We determined differences in demographics, tumor factors, and treatment patterns of prostate cancer patients in a geographic-based cancer registry based on eligibility for a facility-based cancer registry system.

METHODS

We identified prostate cancer patients captured by the Surveillance, Epidemiology, and End Results (SEER) database from 2018 to 2019. Our exposure was receipt of cancer care at a facility accredited by the American College of Surgeons' Commission on Cancer (CoC) providing eligibility for inclusion in the National Cancer Database (NCDB). Outcomes included patient demographics, tumor factors (e.g., biopsy grade), and treatment with radical prostatectomy.

RESULTS

We identified 113,733 prostate cancer patients of whom 65,708 (57%) were NCDB-eligible with an analytic abstract, and 11,010 (10%) were NCDB-eligible without an analytic abstract. NCDB-eligible men were younger (67.0 vs. 68.1 years, P < 0.001), less likely to be Hispanic/Latino (8.7% vs. 13.2%, P < 0.001), and more likely in a county with median income over $75,000 (40.9% vs. 30.0%, P < 0.001). NCDB eligibility varied widely by registry, from 95.9% in Connecticut to 42.6% in Utah. NCDB-ineligible patients were more likely to have unknown stage (17.2% vs. 2.9% NCDB-eligible) and missing PSA (22.9% vs 9.3% NCDB-eligible). NCDB-eligible men were less likely to have Grade Group 1 cancer on biopsy (28.2% vs. 39.2%, P < 0.001). Treatment with prostatectomy was more common among NCDB-eligible patients for low-risk (19.6% vs. 8.8%, adjusted OR 2.30, 95% CI 1.72-6.66) and high-risk tumors (43.5% vs. 26.0%, adjusted OR 1.95, 95% CI 1.33-2.86).

CONCLUSION

Compared NCDB-ineligible patients, those eligible for inclusion in the NCDB have important differences in demographics, eligibility for active surveillance, and treatment patterns. Generalizations related to epidemiologic trends, practice patterns, and outcomes for this select population should be interpreted with caution.