So sánh phương pháp

	Thử nghiệm lâm sàng Giai đoạn II hồi cứu	Thử nghiệm lâm sàng Giai đoạn I
Lĩnh vực	Dịch tễ học	Dịch tễ học
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1980s–1990s (with growth in oncology retrospective analyses)	1960s (formal regulatory framework established ~1963–1970s)
Người khởi xướng	Adapted from standard Phase II trial methodology; retrospective variant formalized in oncology practice	Regulatory and clinical pharmacology community; formalized in U.S. FDA IND regulations (1963) and ICH guidelines
Loại	Observational retrospective study	Interventional clinical study design
Công trình gốc	Simon, R. (1989). Optimal two-stage designs for phase II clinical trials. Controlled Clinical Trials, 10(1), 1–10.	Storer, B. E. (1989). Design and analysis of phase I clinical trials. Biometrics, 45(3), 925–937.
Tên gọi khác	retrospective Phase II study, historical Phase II analysis, retrospective efficacy study, Phase II retrospective analysis	Phase 1 trial, first-in-human study, FIH study, dose-escalation study
Liên quan	5	6
Tóm tắt	A retrospective Phase II clinical trial evaluates a treatment's preliminary efficacy and safety signals using existing archival data — medical records, registries, or electronic health records — rather than prospectively enrolling new patients. It mirrors the objectives of a standard Phase II trial (estimating response rate, tolerability, and early efficacy) but does so by looking backward at patients who have already received the intervention, making it faster and less costly than a prospective design.	A Phase I clinical trial is the first stage of human testing for a new drug, biologic, or intervention. Its primary objective is to evaluate safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) rather than therapeutic efficacy. Small cohorts of participants — typically healthy volunteers or patients with advanced disease — receive sequentially increasing doses to identify the maximum tolerated dose (MTD) and the dose-limiting toxicities (DLTs) that define the boundary for subsequent trials.