{"doi":"10.1002/cam4.71097","title":"Patient, Physician, and Assessor Blinding in Phase <scp>III</scp> Randomized Trials in Oncology: A Meta‐Epidemiological Analysis","abstract":"BACKGROUND: Blinding mitigates bias in randomized trials and may be especially crucial for surrogate endpoints, such as progression-free survival (PFS). Here, we characterize utilization of and factors associated with blinding in Phase III oncology trials with PFS primary endpoints. METHODS: Two-arm, superiority-design trials investigating systemic therapy were identified in May 2024 from ClinicalTrials.gov with no date limitation. Trials were required to have a PFS primary endpoint. The study outcomes were the presence of double-blind designs and blinded independent central review (BICR) for the primary endpoint. Ninety-five percent credible intervals for binary outcomes were estimated from beta distributions, and multivariable logistic regressions explored associations with trial-level features. RESULTS: After screening, 237 trials were included, enrolling 127,518 patients. A double-blind design was used in 105 trials (44%, 95% CrI 38%-51%). BICR was used in 111 trials (47%, 95% CrI 41%-53%), including 39 double-blind trials (16%, 95% CrI 12%-22%). Trials with BICR had higher odds of meeting the primary endpoint (OR 1.84; 95% CI 1.06-3.18; p = 0.03). The PFS assessor identity (central vs. local) or blinding status was not reported in 50 trials (26%, 95% CrI 16%-27%). Trials that met prespecified significance criteria for PFS were more likely to report whether PFS assessors were blinded/unblinded and central/local (OR, 3.05; 95% Cl: 1.60-5.81; p = 0.0007). CONCLUSIONS: Despite the importance of double blinding in combination with BICR for reducing bias, only a few trials blinded physicians, patients, and primary endpoint assessors. This meta-epidemiological study illuminates the prevalence of potential assessment biases affecting PFS in Phase III oncology and secondarily emphasizes the need for improved methodology reporting.","journal":"Cancer Medicine","year":2025,"id":545715,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9492,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":261714,"name":"Pavlos Msaouel","orcid":"0000-0001-6505-8308","position":1,"is_corresponding":false},{"id":1233379,"name":"Avital M. Miller","orcid":"0009-0007-4072-1442","position":2,"is_corresponding":false},{"id":405443,"name":"Ramez Kouzy","orcid":"0000-0002-1521-0495","position":3,"is_corresponding":false},{"id":351184,"name":"Timothy A. Lin","orcid":"0000-0003-4183-9120","position":4,"is_corresponding":false},{"id":405444,"name":"Joseph Abi Jaoude","orcid":"0000-0002-2283-4765","position":5,"is_corresponding":false},{"id":355311,"name":"Ethan B. Ludmir","orcid":"0000-0002-5472-5344","position":6,"is_corresponding":false},{"id":516555,"name":"Alexander D. Sherry","orcid":"0000-0001-5115-1691","position":7,"is_corresponding":false},{"id":324462,"name":"Gabrielle Brown","orcid":null,"position":0,"is_corresponding":true}],"reference_count":41,"raw_metadata":null,"created_at":"2026-07-19T02:53:27.751050Z","pmid":"40879280","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}