Characteristics of Randomized Clinical Trials in Surgery From 2008 to 2020: A Systematic Review.

Importance: Randomized clinical trials (RCTs) provide the highest level of evidence to evaluate 2 or more surgical interventions. Surgical RCTs, however, face unique challenges in design and implementation. Objective: To evaluate the design, conduct, and reporting of contemporary surgical RCTs. Evidence Review: A literature search performed in the 2 journals with the highest impact factor in general medicine as well as 6 key surgical specialties was conducted to identify RCTs published between 2008 and 2020. All RCTs describing a surgical intervention in both experimental and control arms were included. The quality of included data was assessed by establishing an a priori protocol containing all the details to extract. Trial characteristics, fragility index, risk of bias (Cochrane Risk of Bias 2 Tool), pragmatism (Pragmatic Explanatory Continuum Indicator Summary 2 [PRECIS-2]), and reporting bias were assessed. Findings: A total of 388 trials were identified. Of them, 242 (62.4%) were registered; discrepancies with the published protocol were identified in 81 (33.5%). Most trials used superiority design (329 [84.8%]), and intention-to-treat as primary analysis (221 [56.9%]) and were designed to detect a large treatment effect (50.0%; interquartile range [IQR], 24.7%-63.3%). Only 123 trials (31.7%) used major clinical events as the primary outcome. Most trials (303 [78.1%]) did not control for surgeon experience; only 17 trials (4.4%) assessed the quality of the intervention. The median sample size was 122 patients (IQR, 70-245 patients). The median follow-up was 24 months (IQR, 12.0-32.0 months). Most trials (211 [54.4%]) had some concern of bias and 91 (23.5%) had high risk of bias. The mean (SD) PRECIS-2 score was 3.52 (0.65) and increased significantly over the study period. Most trials (212 [54.6%]) reported a neutral result; reporting bias was identified in 109 of 211 (51.7%). The median fragility index was 3.0 (IQR, 1.0-6.0). Multiplicity was detected in 175 trials (45.1%), and only 35 (20.0%) adjusted for multiple comparisons. Conclusions and Relevance: In this systematic review, the size of contemporary surgical trials was small and the focus was on minor clinical events. Trial registration remained suboptimal and discrepancies with the published protocol and reporting bias were frequent. Few trials controlled for surgeon experience or assessed the quality of the intervention.

A classification of methods used to personalize participative interventions revealed inadequate reporting in trial protocols.

OBJECTIVES: The objective of the study was to develop a classification of methods used to personalize participative interventions in randomized controlled trials (RCTs). STUDY DESIGN AND SETTING: We conducted a systematic review including protocols of RCTs assessing participative interventions in PubMed and ClinicalTrials.gov between June 2018 and May 2019. Data extraction was performed by two independent reviewers. We developed a precise classification of methods used to personalize interventions. Then, protocols were reviewed to determine whether personalization was sufficiently described to enable replication. RESULTS: We included 109 protocols. The classification used four components and 13 subcomponents accounting for decision points (when interventions were personalized), tailoring variables (on what interventions were personalized), decision rules (how and by whom interventions were personalized), and nature of the subsequent tailoring (what was personalized in the interventions). In 95% of protocols, at least one component or subcomponent of our classification was not adequately reported to enable the replication of the intervention. Components the least well described were tailoring variables (72% of protocols insufficiently described) and the nature of the subsequent tailoring (46% of protocols). CONCLUSION: This study provides the first detailed classification of methods used to personalize interventions. This is required to transparently implement personalization and improve reporting in RCTs.

Machine learning reduced workload with minimal risk of missing studies: development and evaluation of a randomized controlled trial classifier for Cochrane Reviews.

OBJECTIVES: This study developed, calibrated, and evaluated a machine learning classifier designed to reduce study identification workload in Cochrane for producing systematic reviews. METHODS: A machine learning classifier for retrieving randomized controlled trials (RCTs) was developed (the "Cochrane RCT Classifier"), with the algorithm trained using a data set of title-abstract records from Embase, manually labeled by the Cochrane Crowd. The classifier was then calibrated using a further data set of similar records manually labeled by the Clinical Hedges team, aiming for 99% recall. Finally, the recall of the calibrated classifier was evaluated using records of RCTs included in Cochrane Reviews that had abstracts of sufficient length to allow machine classification. RESULTS: The Cochrane RCT Classifier was trained using 280,620 records (20,454 of which reported RCTs). A classification threshold was set using 49,025 calibration records (1,587 of which reported RCTs), and our bootstrap validation found the classifier had recall of 0.99 (95% confidence interval 0.98-0.99) and precision of 0.08 (95% confidence interval 0.06-0.12) in this data set. The final, calibrated RCT classifier correctly retrieved 43,783 (99.5%) of 44,007 RCTs included in Cochrane Reviews but missed 224 (0.5%). Older records were more likely to be missed than those more recently published. CONCLUSIONS: The Cochrane RCT Classifier can reduce manual study identification workload for Cochrane Reviews, with a very low and acceptable risk of missing eligible RCTs. This classifier now forms part of the Evidence Pipeline, an integrated workflow deployed within Cochrane to help improve the efficiency of the study identification processes that support systematic review production.

Hierarchies of evidence applied to lifestyle Medicine (HEALM): introduction of a strength-of-evidence approach based on a methodological systematic review.

BACKGROUND: Current methods for assessing strength of evidence prioritize the contributions of randomized controlled trials (RCTs). The objective of this study was to characterize strength of evidence (SOE) tools in recent use, identify their application to lifestyle interventions for improved longevity, vitality, or successful aging, and to assess implications of the findings. METHODS: The search strategy was created in PubMed and modified as needed for four additional databases: Embase, AnthropologyPlus, PsycINFO, and Ageline, supplemented by manual searching. Systematic reviews and meta-analyses of intervention trials or observational studies relevant to lifestyle intervention were included if they used a specified SOE tool. Data was collected for each SOE tool. Conditions necessary for assigning the highest SOE grading and treatment of prospective cohort studies within each SOE rating framework were summarized. The expert panel convened to discuss the implications of findings for assessing evidence in the domain of lifestyle medicine. RESULTS AND CONCLUSIONS: A total of 15 unique tools were identified. Ten were tools developed and used by governmental agencies or other equivalent professional bodies and were applicable in a variety of settings. Of these 10, four require consistent results from RCTs of high quality to award the highest rating of evidence. Most SOE tools include prospective cohort studies only to note their secondary contribution to overall SOE as compared to RCTs. We developed a new construct, Hierarchies of Evidence Applied to Lifestyle Medicine (HEALM), to illustrate the feasibility of a tool based on the specific contributions of diverse research methods to understanding lifetime effects of health behaviors. Assessment of evidence relevant to lifestyle medicine requires a potential adaptation of SOE approaches when outcomes and/or exposures obviate exclusive or preferential reliance on RCTs. This systematic review was registered with the International Prospective Register of Systematic Reviews, PROSPERO [CRD42018082148].

Blinding and Patient-Reported Outcome Completion Rates in US Food and Drug Administration Cancer Trial Submissions, 2007-2017.

BACKGROUND: Patient-reported outcomes (PROs) are commonly included in submissions to the United States Food and Drug Administration (FDA). Open-label designs are frequent in cancer trials. Between-arm differences in PRO missingness may affect results. We sought to compare PRO completion rates between study arms in randomized open-label and double-blind cancer trials. METHODS: Randomized, controlled trials for oncology and malignant hematology products submitted to the FDA in fiscal years 2007-2017 were identified using internal FDA databases. Applicant study reports were reviewed to assess PRO use and reporting of completion rates. Completion rates were collected for each PRO and compared between arms. Results were summarized using descriptive statistics. RESULTS: Ninety-six trials for anticancer products from 2007 to 2017 contained PROs. Fifty-one (53.1%) were randomized, controlled trials with useable information on PRO completion. The median completion rate for investigational arms was 89.7% (range = 33.7-100.0%) and 88.2% (range = 11.0-100.0%) for control arms. At six months, seven double-blind trials had gaps of at least 10% in at least one PRO between arms; in four trials, these gaps favored the control arm (median difference = 11.5%, range = 10.0-17.0%). For open-label trials, four trials had such gaps, all of which favored the investigational arm (median difference = 28.5%, range = 10.0-69.0%). CONCLUSIONS: Among trials that provided interpretable PRO completion information, completion rates were high. Most trials had comparable completion rates between arms. However, when large between-arm completion rate differences existed, differences favoring the experimental arm were more common in open-label trials compared with double-blind trials. Procedures must be put in place to improve reporting of PRO completion and reduce missingness, particularly in open-label trials.

Evaluación de los Ensayos Clínicos Aleatorios desarrollados por enfermeras según los criterios de la Declaración CONSORT / Evaluation of randomized clinical essays developed by nurses according to the consort declaration criteria

Objetivo: Evaluar si los Ensayos Clínicos Aleatorizados (ECAS) realizados por enfermeras en los últimos siete años, cumplen con la rigurosidad metodológica establecida por los criterios de la Declaración CONSORT. Métodos: Revisión integrativa de la literatura de revistas de enfermería, se analizaron 66 ECAS realizados por enfermeras y publicados en 11 revistas indizadas en bases de datos reconocidas, en cuyo título, palabras clave o diseño se reconocieran como un ensayo clínico aleatorio. Se realizó un instrumento de 48 ítems para evaluar las características de los 66 ECAS publicados. Dicho instrumento está dividido en dos segmentos: el primero evalúa información general de los artículos y el segundo incluye las características de la Declaración CONSORT. Resultados: El 57.6% de los ECAS utilizaron grupo control equivalente, 87.9% utilizó muestreo aleatorio, 28.8% enmascaramiento, 54.5% presentaron diagrama de flujo, 83% realizaron aleatorización, 57.6% describen las intervenciones empleadas a los grupos de estudio. Conclusiones: De forma general, los ECAS publicados por enfermería en los últimos siete años no cumplen con los criterios de la Declaración CONSORT. Estos hallazgos representan un área de oportunidad para que editores de revistas de enfermería soliciten a los autores mayor apego a la rigurosidad metodológica en sus artículos de acuerdo a los criterios de la Declaración CONSORT (AU)

Objective: Evaluate if the Randomized Clinical Trials (RCTs) carried out by nurses in the last seven years fulfill the methodological rigor established by the CONSORT declaration criteria. Methods: Nursing journals literature integral review; sixty-six RCTs carried out by nurses and published in 11 indexed journals within recognized data bases were analyzed and where their title, key words or design allowed them to be recognized as a randomized clinical essay. A 48 item instrument was realized to evaluate the characteristics of the 66 published RCTs. Such instrument is divides in two segments: the first one evaluates general information in the articles, and the second one includes the CONSORT Declaration characteristics. Results: The 57.6% of RCTs used an equivalent control group, 87.9% used randomized sampling, 28.8% blind, 54.5% presented flow chart, groups. Conclusions: In general, the RCTs published by nursing in the last seven years do not fulfill the CONSORT Declaration criteria. These findings present an opportunity area so nursing journals publishers request from the authors the most attachment to the methodological rigor in their articles, according to the CONSORT Declaration criteria (AU)

Cost-Effectiveness Analysis of New HCV Treatments in Egyptian Cirrhotic and Non-Cirrhotic Patients: A Societal Perspective.

OBJECTIVES: To evaluate the cost-effectiveness of sofosbuvir (SOF) + ribavirin (RBV), SOF + daclatasvir (DCV), and SOF + ledipasvir (LDV) + RBV compared with SOF + pegylated interferon alfa (pegIFN) + RBV in the treatment of patients infected with hepatitis C virus in Egypt. METHODS: Two Markov models were developed on the basis of the Egyptian clinical data and practice and were derived from published sources. The clinical parameters were derived from two sources: the Egypt multicenter national treatment program and previously published randomized clinical trials. The utility of the health states was derived using the available published data. Direct medical costs were obtained from the National Liver Institute database. RESULTS: In noncirrhotic patients, incremental cost-effectiveness ratios of US $2330 per quality-adjusted life-year (QALY) gained for the SOF + LDV + RBV, -US $9043/QALY for the SOF + DCV, and -US $1332/QALY for the SOF + RBV regimens were yielded. In cirrhotic patients, incremental cost-effectiveness ratios of -US $4170/QALY gained for the SOF + LDV + RBV, -US $9515/QALY for the SOF + DCV, and -US $2289/QALY for the SOF + RBV regimens were yielded. The SOF + DCV regimen was the most cost-saving option for cirrhotic and noncirrhotic patients. Deterministic sensitivity analyses remain robust. CONCLUSIONS: The present study concludes that the SOF + DCV regimen among other currently available regimens is the most cost-saving option that yields the most favorable future health economic outcomes compared with the SOF + pegIFN + RBV regimen across a broad spectrum of patients, including those with cirrhosis.

Ensayos clínicos por conglomerados (clusters) / Clinical trials by conglomerates (clusters)

Un ensayo clínico aleatorizado por conglomerados se da cuando se aleatorizan grupos (clusters) de individuos a las distintas ramas. Puede ser la única o mejor opción de diseño ante determinadas circunstancias: si hay un claro agrupamiento (biológico o funcional) en donde algunos individuos de análisis son más parecidos entre sí que otros; si las intervenciones a evaluar se realizan a nivel del conglomerado; cuando hay riesgo de contaminación; o por practicidad, costos o conveniencia. Entre los problemas más importantes que conllevan se encuentran posibles sesgos (especialmente cuando el reclutamiento de los individuos se realiza luego de la aleatorización, o no existe ceguera), así como mayor complejidad en el diseño y análisis. Asimismo, si no se tienen en cuenta la agrupación de individuos por conglomerados para el cálculo del tamaño muestral o del análisis de los datos, se podrían obtener resultados incorrectos. Estos estudios deben explicitar, además de lo habitualmente reportado: por qué se decidió realizar un diseño por conglomerados; si los objetivos, intervenciones y puntos finales a evaluar apuntan a nivel del conglomerado, individual, o ambos; describir los criterios de inclusión a nivel del conglomerado e individual; mostrar cómo se hicieron el cálculo del tamaño muestral y los análisis considerando los conglomerados; aclarar si los pacientes, profesionales actuantes e investigadores estaban ciegos a las ramas de investigación; y discutir la generalizabilidad de los resultados, entre otros. Si bien tienen mayor complejidad, estos estudios son cada vez más frecuentes. Es un diseño muy útil si está bien desarrollado y es importante conocer sus particularidades. (AU)

We perform a cluster randomized controlled trial when we randomize groups (or clusters) of individuals (whether humans, cells, or clinics) to different study arms, and not simply individuals. It can be the only or best study design option in certain circum-stances: if there is a clear grouping, when some subjects of analysis are more similar among them than the rest; if interventions to be evaluated are made at cluster level; when there is risk of "contamination" or cross-over; or because of practicality, costs or convenience according to researchers judgment. Cluster trials are associated with important issues: risk of bias (especially when individuals recruitment is made after randomization, or if there was no blinding); and the need of more complex design and analysis. If we do not take clusters into account in the sample size estimation and data analysis, we could get misleading results.When reporting these studies, researchers should make explicit (in addition to standard reporting requirements): the rationale for a cluster design; if the objectives, interventions and endpoints are for clusters, individuals or both; the inclusion criteria for clusters and individuals; how they did sample size estimations and data analysis considering cluster design; if patients, health care profes-sionals and researchers were blind; and if results can be generalized. Even though cluster randomized controlled trials are more complex, these studies are increasingly common. It is a very useful design, if correctly done. And it is important to understand its main characteristics. (AU)

Randomized Trials in Developing Countries: Different Priorities and Study Design?

BACKGROUND: Clinical trials are increasingly conducted in the field of neurology in developing countries. To our knowledge, no review has been performed to date about the temporal evolution, geographical distribution, pathological fields, and types of trials conducted. Besides, the validity of those clinical trials needs to be evaluated. SUMMARY: Our main aim was to describe, using a systematic literature review, the clinical trials performed in the field of neurology in developing countries. The specific objectives were (1) to describe the pathologic fields, (2) to evaluate the methodology, and (3) to assess the validity of neurological clinical trials performed in developing countries. A systematic review of the literature was conducted accessing PubMed, Pascal, ScienceDirect, African Journal Online, and the Virtual Library of African Neurology. The 145 studies included allowed us to identify (1) an exponential evolution of the number of clinical trials, (2) the strong contributions from Asia, followed by Africa and Latin America, (3) a fairly good coverage of pathologic fields including noncommunicable diseases, (4) an increasing diversity of intervention type, (5) the lack of early-phase trials (phases I and IIa), and (5) the need of improvement for some critical methodological issues. KEY MESSAGE: There is a need (1) to develop structures dedicated to the early investigation of interventions in humans, and (2) for sustaining the development of structures specialized in the methodology of clinical research and of dedicated courses for researchers in tropical areas about good practice in clinical trials. This would help in improving methodological quality, appropriateness of data management, and statistical analysis.

A qualitative exploration of trial-related terminology in a study involving Deaf British Sign Language users.

BACKGROUND: Internationally, few clinical trials have involved Deaf people who use a signed language and none have involved BSL (British Sign Language) users. Appropriate terminology in BSL for key concepts in clinical trials that are relevant to recruitment and participant information materials, to support informed consent, do not exist. Barriers to conceptual understanding of trial participation and sources of misunderstanding relevant to the Deaf community are undocumented. METHODS: A qualitative, community participatory exploration of trial terminology including conceptual understanding of 'randomisation', 'trial', 'informed choice' and 'consent' was facilitated in BSL involving 19 participants in five focus groups. Data were video-recorded and analysed in source language (BSL) using a phenomenological approach. RESULTS AND DISCUSSION: Six necessary conditions for developing trial information to support comprehension were identified. These included: developing appropriate expressions and terminology from a community basis, rather than testing out previously derived translations from a different language; paying attention to language-specific features which support best means of expression (in the case of BSL expectations of specificity, verb directionality, handshape); bilingual influences on comprehension; deliberate orientation of information to avoid misunderstanding not just to promote accessibility; sensitivity to barriers to discussion about intelligibility of information that are cultural and social in origin, rather than linguistic; the importance of using contemporary language-in-use, rather than jargon-free or plain language, to support meaningful understanding. CONCLUSIONS: The study reinforces the ethical imperative to ensure trial participants who are Deaf are provided with optimum resources to understand the implications of participation and to make an informed choice. Results are relevant to the development of trial information in other signed languages as well as in spoken/written languages when participants' language use is different from the dominant language of the country.

Differences between the real and the desired worlds in the results of clinical trials.

OBJECTIVE: We refer to the effectiveness (known as pragmatic or real world) and efficacy (known as explanatory or desired or ideal world) of interventions. However, these terms seem to be randomly chosen by investigators who design clinical trials and do not always reflect the true purpose of the study. A pragmatic-explanatory continuum indicator summary tool was thus developed with the aim of identifying the characteristics of clinical trials that distinguish between effectiveness and efficacy issues. We verified whether clinical trials used the criteria proposed by the indicator summary tool, and we categorized these clinical trials according to a new classification. METHOD: A systematic survey of randomized clinical trials was performed. We added a score ranging from 0 (more efficacious) to 10 (more effective) to each domain of the indicator summary tool and proposed the following classifications: high efficacy (<25), moderate efficacy (25-50), moderate effectiveness (51-75), and high effectiveness (<75). RESULTS: A total of 844 randomized trials were analyzed. No analyzed trials used the criteria proposed by the indicator summary tool. Approximately 44% of the trials were classified as having moderate effectiveness, and 43.82% were classified as having moderate efficacy. CONCLUSIONS: Most clinical trials used the term "efficacy" to illustrate the application of results in clinical practice, but the majority of those were classified as having moderate effectiveness according to our proposed score. The classification based on the 0-100 score is still highly subjective and can be easily misunderstood in all domains based on each investigator's own experiences and knowledge.

Differences between the real and the desired worlds in the results of clinical trials

OBJECTIVE:We refer to the effectiveness (known as pragmatic or real world) and efficacy (known as explanatory or desired or ideal world) of interventions. However, these terms seem to be randomly chosen by investigators who design clinical trials and do not always reflect the true purpose of the study. A pragmatic-explanatory continuum indicator summary tool was thus developed with the aim of identifying the characteristics of clinical trials that distinguish between effectiveness and efficacy issues. We verified whether clinical trials used the criteria proposed by the indicator summary tool, and we categorized these clinical trials according to a new classification.METHOD:A systematic survey of randomized clinical trials was performed. We added a score ranging from 0 (more efficacious) to 10 (more effective) to each domain of the indicator summary tool and proposed the following classifications: high efficacy (<25), moderate efficacy (25-50), moderate effectiveness (51-75), and high effectiveness (<75).RESULTS:A total of 844 randomized trials were analyzed. No analyzed trials used the criteria proposed by the indicator summary tool. Approximately 44% of the trials were classified as having moderate effectiveness, and 43.82% were classified as having moderate efficacy.CONCLUSIONS:Most clinical trials used the term “efficacy” to illustrate the application of results in clinical practice, but the majority of those were classified as having moderate effectiveness according to our proposed score. The classification based on the 0-100 score is still highly subjective and can be easily misunderstood in all domains based on each investigator’s own experiences and knowledge.

An assessment of randomized controlled trials (RCTs) for non-communicable diseases (NCDs): more and higher quality research is required in less developed countries.

Research is crucial to implement evidence-based health interventions for control of non-communicable diseases (NCDs). This study aims to assess main features of randomized controlled trials (RCTs) for control of NCDs, and to identify gaps in clinical research on NCDs between high-income and less developed countries. The study included 1177 RCTs in 82 Cochrane Systematic reviews (CSRs) and evaluated interventions for adults with hypertension, diabetes, stroke, or heart diseases. Multivariate logistic regression analyses were conducted to explore factors associated with risk of bias in included RCTs. We found that 78.2% of RCTs of interventions for major NCDs recruited patients in high-income countries. The number of RCTs included in the CSRs was increasing over time, and the increasing speed was more noticeable for RCTs conducted in middle-income countries. RCTs conducted in less developed countries tended to be more recently published, less likely to be published in English, with smaller sample sizes, and at a higher risk of bias. In conclusion, there is still a lack of research evidence for control of NCDs in less developed countries. To brace for rising NCDs and avoid waste of scarce research resources, not only more but also higher quality clinical trials are required in low-and-middle-income countries.

Assessing the Collective Population Representativeness of Related Type 2 Diabetes Trials by Combining Public Data from ClinicalTrials.gov and NHANES.

Randomized controlled trials generate high-quality medical evidence. However, the use of unjustified inclusion/exclusion criteria may compromise the external validity of a study. We have introduced a method to assess the population representativeness of related clinical trials using electronic health record (EHR) data. As EHR data may not perfectly represent the real-world patient population, in this work, we further validated the method and its results using the National Health and Nutrition Examination Survey (NHANES) data. We visualized and quantified the differences in the distributions of age, HbA1c, and BMI among the target population of Type 2 diabetes trials, diabetics in NHANES databases, and a convenience sample of patients enrolled in selected Type 2 diabetes trials. The results are consistent with the previous study.

Guidelines for time-to-event end point definitions in breast cancer trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†.

BACKGROUND: Using surrogate end points for overall survival, such as disease-free survival, is increasingly common in randomized controlled trials. However, the definitions of several of these time-to-event (TTE) end points are imprecisely which limits interpretation and cross-trial comparisons. The estimation of treatment effects may be directly affected by the definitions of end points. The DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for randomized cancer clinical trials (RCTs) in breast cancer. PATIENTS AND METHODS: A literature review was carried out to identify TTE end points (primary or secondary) reported in publications of randomized trials or guidelines. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points based on a validated consensus method that formalize the degree of agreement among experts. RESULTS: Recommended guidelines for the definitions of TTE end points commonly used in RCTs for breast cancer are provided for non-metastatic and metastatic settings. CONCLUSION: The use of standardized definitions should facilitate comparisons of trial results and improve the quality of trial design and reporting. These guidelines could be of particular interest to those involved in the design, conducting, reporting, or assessment of RCT.

Guidelines for time-to-event end point definitions in sarcomas and gastrointestinal stromal tumors (GIST) trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†.

BACKGROUND: The use of potential surrogate end points for overall survival, such as disease-free survival (DFS) or time-to-treatment failure (TTF) is increasingly common in randomized controlled trials (RCTs) in cancer. However, the definition of time-to-event (TTE) end points is rarely precise and lacks uniformity across trials. End point definition can impact trial results by affecting estimation of treatment effect and statistical power. The DATECAN initiative (Definition for the Assessment of Time-to-event End points in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for RCT in sarcomas and gastrointestinal stromal tumors (GIST). METHODS: We first carried out a literature review to identify TTE end points (primary or secondary) reported in publications of RCT. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points. Recommendations were developed through a validated consensus method formalizing the degree of agreement among experts. RESULTS: Recommended guidelines for the definition of TTE end points commonly used in RCT for sarcomas and GIST are provided for adjuvant and metastatic settings, including DFS, TTF, time to progression and others. CONCLUSION: Use of standardized definitions should facilitate comparison of trials' results, and improve the quality of trial design and reporting. These guidelines could be of particular interest to research scientists involved in the design, conduct, reporting or assessment of RCT such as investigators, statisticians, reviewers, editors or regulatory authorities.