Derivation and reporting of objective performance criteria and performance goals in single‑arm TCM studies: A methodological survey

Single-arm studies using Objective Performance Criteria (OPC) or Performance Goals (PG) offer an alternative when concurrent controls are impractical. This approach holds particular promise in traditional Chinese medicine (TCM), where strong patient preferences limit the feasibility of concurrent controls. However, the derivation and reporting of OPC/PG lack standardization. Eight databases were searched for single-arm studies using OPC/PG as comparators. Data sources and derivation methods of OPC/PG were extracted; transparency and replicability were evaluated. Derivation methods were categorized and assessed; applications in TCM were summarized. Multiple correspondence analysis (MCA) examined associations among derivation methods, disease categories, and intervention types. A total of 125 single-arm studies with 178 OPC/PG were included. Only 41 OPC/PG were replicable, including 32 direct quotations. Seven derivation methods were identified: quotation of existing OPC/PG (7.3%), regulatory authority-defined (3.4%), meta-analysis (10.1%), statistical model derivation (3.9%), weighted averaging of multiple studies (15.7%), quotation from a single study (17.4%), and investigator-defined (42.1%). In TCM, seven studies with nine OPC/PG were included; five were quoted from a single study, and four were investigator-defined. MCA revealed TCM clustered with simple OPC/PG derivation methods and diverse disease areas. OPC/PG derivation is characterized by diverse methods, insufficient reporting, and poor replicability, with most approaches not aligned with FDA guidance. In TCM, applications as explicitly reported in the studies included in this review remain exploratory, relying on simple derivation methods and lacking transparency. Standardized methodological guidance and reporting checklists are urgently needed, particularly for TCM. The protocol of this study was registered on Open Science Framework Registries (10.17605/OSF.IO/EJT5W).