Evaluating the Environmental Impact of Clinical Research: A Full Life Cycle Analysis of a French Academic Randomised Clinical Trial.
Climate change poses the greatest threat to human health in the 21st century. The healthcare sector contributes approximately 5% of global greenhouse gas emissions and has a significant environmental impact. Although clinical trials are crucial for identifying effective and safe treatments and preventing disease, their environmental impact is poorly documented. Our study aimed to assess the environmental impact of a publicly funded, academic clinical trial by adapting life cycle assessment (LCA) methodology to clinical research. We performed a retrospective, simplified, full LCA using the EF 3.0 methodology on a prospective, double-blind, randomised controlled neurosurgery trial. The trial included 202 patients at 18 university hospitals throughout France. To identify hotspots of interest, 16 impact indicators and their combination into a single score were evaluated. The results showed that climate change (or greenhouse gas emissions) was the most important indicator, accounting for almost 30% of the single score. Greenhouse gas emissions were estimated at 31.6 t of carbon dioxide equivalent. The next most important were resource use of fossils (24%), resource use of minerals and metals (12%), and particulate matter emissions (8%). The main hotspots identified were patient transport and travel by clinical research assistants for source data verification. In conclusion, by using a full LCA approach, our study confirms that conducting a clinical trial has a substantial environmental impact, particularly with regard to greenhouse gas emissions. The main hotspots identified were related to patient transport and clinical research assistants' travel. Trial Registration: The SUCRE study (Treatment of Chronic Subdural Hematoma by Corticosteroids: A Prospective Randomised Study)-clinicaltrials.gov identifier: NCT02650609.
- Single Report
5
- 10.2172/2308833
- Apr 1, 2020
Using a life cycle assessment (LCA), the environmental impacts from generating 1 kWh of electricity for self-consumption via a photovoltaic-battery system are determined. The system includes a 10 kWp multicrystalline-silicon photovoltaic (PV) system (solar irradiation about 1350 kWh/m2/year and annual yield 1000 kWh/kWp), an iron phosphate lithium-ion (LiFePO4) battery, and other components such as the control system, battery housing, and two inverters (one for the PV system and one for the battery system). Three options for the AC-coupled system with changing battery capacities (5, 10, or 20 kWh nominal capacity) are investigated. The environmental impacts are assessed using the indicators greenhouse gas emissions and cumulative energy demand (separated into total and non-renewable cumulative energy demand). In addition, the four most important impact categories for PV electricity - respiratory inorganics (particulate matter), acidification, energy carrier resource use, and minerals and metals resource use - are assessed according to the environmental footprint (EF) method. Data are drawn from the DETEC data DQRv2:2018, recent literature, and product details provided by manufacturers. The results show larger environmental impacts of PV-battery systems with increasing battery capacity; for capacities of 5, 10, and 20 kWh, the cumulative greenhouse gas emissions from 1 kWh of electricity generation for self-consumption via a PV-battery system are 80, 84, and 88 g CO2-eq/kWh, respectively. The cumulative greenhouse gas emissions of PV electricity consumed directly or fed into the grid are 54 g CO2-eq/kWh. The corresponding total cumulative energy demands are 5.27, 5.40, and 5.50 MJ oil-eq/kWh, with non-renewable energy carriers contributing 1.16, 1.22, and 1.29 MJ oil-eq/kWh. In the investigated EF impact categories, we similarly observe a larger environmental burden with increasing battery capacity, except in the use of minerals and metals. Our sensitivity analyses show that using a nickel cobalt manganese oxide (NCM) lithium-ion battery, instead of an LiFePO4 battery, leads to a comparable environmental impact in terms of greenhouse gas emissions and cumulative energy demand. However, the NCM battery increases the impact in the EF categories of acidification and respiratory inorganics by 7 and 10%, respectively, whereas energy carrier resource use decreases by 4% and minerals and metals resource use decrease by 1%. Using a copper indium selenium (CIS) PV panel instead of a multicrystalline-silicon decreases greenhouse gas emissions by 24%, non-renewable cumulative energy demand by 13%, and particulate matter emissions by 60% (the largest decrease). Furthermore, the calculated environmental impacts are sensitive to the assumed battery lifetime. A decrease from 5000 to 3000 charge cycles increases non-renewable cumulative energy demand by 24% and greenhouse gas emissions by 16%. Increasing from 5000 to 7000 charge cycles decreases the environmental impacts by 6% and 7% in terms of non-renewable cumulative energy demand and greenhouse gas emissions, respectively. A utility-scale battery system case study shows that using batteries to store PV electricity overproduction reduces greenhouse gas emissions compared to using natural gas backup electricity generation.
- Research Article
4
- 10.1136/bmjopen-2024-085364
- Feb 1, 2025
- BMJ Open
ObjectiveThis study aims to calculate the global warming potential, in carbon dioxide (CO2) equivalent emissions, from all in-scope activities involved in phase 1, 2, 3 and 4 clinical trials spanning...
- Research Article
2
- 10.1016/j.farsys.2025.100195
- Apr 1, 2026
- Farming System
From soil carbon towards system sustainability: Integrating SOC modelling and life cycle assessment to evaluate environmental trade-offs in carbon farming
- Research Article
1
- 10.1158/1538-7755.disp18-a083
- Jun 1, 2020
- Cancer Epidemiology, Biomarkers & Prevention
Background: Breast cancer (BC) prevention clinical trials (CTs) play a vital role in the progress of preventative measures and treatments for all races and ethnicities. However, Northern European whites (NE/W) continue to be disproportionally enrolled (e.g., 93.5% were non-Hispanic white in the STAR trial), while minorities such as Asians, blacks, Latinas, and Native Americans (NA) lag in participation. Current studies suggest that minorities are not approached as frequently as NE/W; however, they are just as willing to participate. Here we present a successful recruitment strategy to improving minority accrual in CTs at a Comprehensive Cancer Center located in Duarte, CA. Method: Results from community focus groups suggested the need to mentor local youth who strive to pursue a career in the medical field. Consequently, from February 2016 to July 2018, four bilingual, bicultural clinical research assistants (CRAs) were recruited from the catchment area of City of Hope (CoH). The CRAs, in collaboration with seven surgeons, two radiologists, and one medical oncologist, led the recruitment for three nontherapeutic BC prevention CTs at CoH. Results: All four CRAs were 1) first-generation American, 2) fluent in Spanish or Vietnamese, 3) born and raised in Southern California, and 4) pre-health. Of the 3,148 patients who were screened, 398 were eligible for enrollment, 369 consented, and 58 declined. Primary languages and races/ethnicities of those who declined include the following: 7% Armenian, 9% Chinese, 78% English, 2% Thai, and 5% Spanish; 28% Asian, 3% black, 28% Latina, 2% NA, and 67% white (22% NE, 17% Middle Eastern/North African). Demographics of the consenting population include the following: primary language - >1% Armenian, 4% Chinese, 89% English, >1% Korean, and 7% Spanish; race/ethnicity - 14% Asian, 6% black, 30% Latina, 5% NA, and 75% white (40% NE). Of the white population (n = 277), 11% were Middle Eastern/North African, 53% NE, and 36% Latina. Accrual surpassed both the CoH catchment area (11.3% Asian, 8% black, 24% Hispanic, 1% NA, and 32% NE/W) and the CoH interventional/nontherapeutic CT population (10% Asian/Pacific Islander, 4% black, 21% Hispanic, >1% NA, and 55% NE/W). Conclusion: Contrary to current accrual of CTs, here we show that minorities can have a large representation in CT accrual, as long as they are provided the opportunity. Accrual of Asians, Latinas, and NAs exceeded the catchment area and accrual of other CoH CTs. Interestingly, Chinese-speaking women comprised the highest declination group of the non-English speakers, and Asians and Latinas declined the most outside of non-whites. Cultural competency and bilingualism appear to be characteristics of a CRA that may help in accruing minority women into CTs. Our findings suggest that they are just as willing to participate, and the first step is to simply ask. Citation Format: Tanya A. Chavez, Christine Thai, Angelica Sanchez, Laura L. Kruper, Veronica C. Jones, Sharon Clancy, Amy C. Polverini, Lisa D. Yee, Courtney A. Vito, Noé R. Chávez, Alan Nuñez, Ellen J. Rippberger, Angela K. Wong, Karen Herold, Chidimma M.K. Kalu, Jackelyn A. Alva-Ornelas, Jerneja Tomsic, Krista M. Round, Margarita Robles, Ombeni Idassi, Kendall J. Kennedy, Terry Hyslop, Carola M. Zalles, Christopher Sistrunk, Victoria L. Seewaldt. Diversifying breast cancer clinical trial accrual: An approach to recruitment at a Comprehensive Cancer Center [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A083.
- Research Article
26
- 10.1016/j.oneear.2020.06.014
- Jul 1, 2020
- One Earth
Feeding a growing, increasingly affluent population while limiting environmental pressures of food production is a central challenge for society. Understanding the location and magnitude of food production is key to addressing this challenge because pressures vary substantially across food production types. Applying data and models from life cycle assessment with the methodologies for mapping cumulative environmental impacts of human activities (hereafter cumulative impact mapping) provides a powerful approach to spatially map the cumulative environmental pressure of food production in a way that is consistent and comprehensive across food types. However, these methodologies have yet to be combined. By synthesizing life cycle assessment and cumulative impact mapping methodologies, we provide guidance for comprehensively and cumulatively mapping the environmental pressures (e.g., greenhouse gas emissions, spatial occupancy, and freshwater use) associated with food production systems. This spatial approach enables quantification of current and potential future environmental pressures, which is needed for decision makers to create more sustainable food policies and practices.
- Research Article
59
- 10.1111/j.1530-9290.2012.00477.x
- Apr 1, 2012
- Journal of Industrial Ecology
The body of life cycle assessment (LCA) literature is vast and has grown over the last decade at a dauntingly rapid rate. Many LCAs have been published on the same or very similar technologies or products, in some cases leading to hundreds of publications. One result is the impression among decision makers that LCAs are inconclusive, owing to perceived and real variability in published estimates of life cycle impacts. Despite the extensive available literature and policy need formore conclusive assessments, only modest attempts have been made to synthesize previous research. A significant challenge to doing so are differences in characteristics of the considered technologies and inconsistencies in methodological choices (e.g., system boundaries, coproduct allocation, and impact assessment methods) among the studies that hamper easy comparisons and related decision support. An emerging trend is meta-analysis of a set of results from LCAs, which has the potential to clarify the impacts of a particular technology, process, product, or material and produce more robust and policy-relevant results. Meta-analysis in this context is defined here as an analysis of a set of published LCA results to estimate a single or multiple impacts for a single technology or a technology category, either in a statisticalmore » sense (e.g., following the practice in the biomedical sciences) or by quantitative adjustment of the underlying studies to make them more methodologically consistent. One example of the latter approach was published in Science by Farrell and colleagues (2006) clarifying the net energy and greenhouse gas (GHG) emissions of ethanol, in which adjustments included the addition of coproduct credit, the addition and subtraction of processes within the system boundary, and a reconciliation of differences in the definition of net energy metrics. Such adjustments therefore provide an even playing field on which all studies can be considered and at the same time specify the conditions of the playing field itself. Understanding the conditions under which a meta-analysis was conducted is important for proper interpretation of both the magnitude and variability in results. This special supplemental issue of the Journal of Industrial Ecology includes 12 high-quality metaanalyses and critical reviews of LCAs that advance understanding of the life cycle environmental impacts of different technologies, processes, products, and materials. Also published are three contributions on methodology and related discussions of the role of meta-analysis in LCA. The goal of this special supplemental issue is to contribute to the state of the science in LCA beyond the core practice of producing independent studies on specific products or technologies by highlighting the ability of meta-analysis of LCAs to advance understanding in areas of extensive existing literature. The inspiration for the issue came from a series of meta-analyses of life cycle GHG emissions from electricity generation technologies based on research from the LCA Harmonization Project of the National Renewable Energy Laboratory (NREL), a laboratory of the U.S. Department of Energy, which also provided financial support for this special supplemental issue. (See the editorial from this special supplemental issue [Lifset 2012], which introduces this supplemental issue and discusses the origins, funding, peer review, and other aspects.) The first article on reporting considerations for meta-analyses/critical reviews for LCA is from Heath and Mann (2012), who describe the methods used and experience gained in NREL's LCA Harmonization Project, which produced six of the studies in this special supplemental issue. Their harmonization approach adapts key features of systematic review to identify and screen published LCAs followed by a meta-analytical procedure to adjust published estimates to ones based on a consistent set of methods and assumptions to allow interstudy comparisons and conclusions to be made. In a second study on methods, Zumsteg and colleagues (2012) propose a checklist for a standardized technique to assist in conducting and reporting systematic reviews of LCAs, including meta-analysis, that is based on a framework used in evidence-based medicine. Widespread use of such a checklist would facilitate planning successful reviews, improve the ability to identify systematic reviews in literature searches, ease the ability to update content in future reviews, and allow more transparency of methods to ease peer review and more appropriately generalize findings. Finally, Zamagni and colleagues (2012) propose an approach, inspired by a meta-analysis, for categorizing main methodological topics, reconciling diverging methodological developments, and identifying future research directions in LCA. Their procedure involves the carrying out of a literature review on articles selected according to predefined criteria.« less
- Discussion
1
- 10.3945/an.115.008573
- May 1, 2015
- Advances in Nutrition
Reply to L Aleksandrowicz et al.
- Research Article
44
- 10.1007/s11367-014-0805-3
- Nov 4, 2014
- The International Journal of Life Cycle Assessment
Construction, as a sector of the economy, is a significant source of negative environmental impacts. The development of sustainable construction and associated initiatives are meant to reduce that impact. Buildings, for many reasons, are the complex objects of life cycle assessment (LCA) studies, which in this case can be particularly time-, data- and cost-consuming. Therefore, an attempt was made to explore the possibility of finding a methodological compromise between a full LCA and the compulsory energy certification. Six methodological variants, so called compromise solutions (CS) were identified and assessed. This article presents the results of the research project financed by the Polish Ministry of Science and Higher Education (N N309 078138) and coordinated by the Wood Technology Institute in Poznan. The proposed CS were hybrids utilising, to various degrees, the environmental life cycle assessment (LCA) and energy certification. Life cycle impact assessments were carried out using IMPACT 2002+. The achieved results showed that the simplifications included in the energy certification lead to a significant drop in environmental impacts (by 77.9 % on average) in relation to the impact calculated for the full LCA. The results closest to the full LCA were achieved by the compromise solution no. 4 (CS4), where simplification included the exclusion from the life cycle of: transport processes, construction site, demolition, final disposal of waste, and the majority of elements associated with the use of the building. CS4 analysed all inventory inputs which were assessed with regard to the entire environmental profile. The following truncation levels were achieved for CS4—10.7 % (conventional masonry building), 9.9 % (passive masonry building), 8.3 % (conventional wooden building) and 7.4 % (passive wooden building), indicating that 90 % of the impact calculated for the full LCA was retained. CS4 seems to be a rational compromise between the simplicity of the methodology and the environmental significance. With the exception of the energy usage for heating, hot water and ventilation, CS4 also proposes including, in the analysis, the production of building material and additional elements associated with the use stage, e.g. energy usage for home appliances and lighting, land occupation, water use and wastewater treatment. However, if we were to find a rational minimum, which is close to the energy certification, then a good improvement of this methodology would be to include energy usage for home appliances and lighting as well as introducing conversion indicators, based not only on the depletion of energy resources, but also factoring in global warming and respiratory effects/inorganic compounds. Moreover, it seems that the LCA methodology and, specifically, characterisation factors, are refined to such a degree and scientifically proved that it would be possible to use the knowledge with regard to LCA to establish such indicators for energy certification.
- Research Article
47
- 10.1016/j.jclepro.2018.06.006
- Jun 4, 2018
- Journal of Cleaner Production
Assessment of greenhouse gas emissions of ventilated timber wall constructions based on parametric LCA
- Research Article
32
- 10.1007/s11367-018-01579-2
- Jan 8, 2019
- The International Journal of Life Cycle Assessment
Low-carbon emissions are usually related to hydropower energy, making it an attractive option for nations with hydropower potential as it enables them to meet increasing electricity demand without relying on burning fossil fuels. In fact, the new wave of hydropower plant construction is occurring mainly in tropical areas where an additional environmental impact must be considered: biogenic greenhouse gas (GHG) emissions due to the degradation of biogenic carbon in reservoirs. Peru is planning to install up to 2000 MW in hydropower until 2021, but the input and output flows, as well as the environmental impacts that these generate, have not been explored. Hence, a set of three hydropower plants built in the past decade located in the Peruvian Andes were analyzed from a life cycle perspective. The main objective of the study is to generate detailed life cycle inventories for each of these three hydropower plants with the aim of obtaining specific information for current conditions in Peru. The life cycle assessment methodology was applied to compute the environmental impacts. Data collection was based mainly on primary data obtained directly from the hydropower companies, although biogenic emissions were modeled considering local net primary productivity conditions and other site-specific conditions. Although the calculation of GHG emissions related to hydropower plants was a priority, considering the important policy implications of decarbonizing the Peruvian electricity grid, other environmental categories, such as eutrophication or the depletion of abiotic resources, were also considered. The IPCC method was used to calculate GHG emissions, whereas a set of eight additional impact categories were computed using the ReCiPe 2016 method. Results show that GHG emissions per unit of electricity generated were in the lower range of emissions observed in the literature, in all three cases below 3 g CO2eq/kWh. Biogenic emissions represented less than 5% of the total GHG emissions despite their location in a tropical nation, due to the arid conditions of the landscape in the Andean Highlands, as well as the mild temperatures that are present in the reservoirs. In terms of stratospheric ozone depletion, a GHG with ozone depletion properties, N2O, was the main source of impact. The results are intended to be of utility for an array of applications, including relevance in decision-making in the energy sector and policy-making at a national level, considering the implications in terms of meeting the nationally determined contributions to mitigate climate change in the frame of the Treaty of Paris.
- Front Matter
36
- 10.1016/j.ijrobp.2022.04.039
- Jul 13, 2022
- International Journal of Radiation Oncology*Biology*Physics
Transitioning to Environmentally Sustainable, Climate-Smart Radiation Oncology Care
- Dissertation
- 10.18174/395219
- Jan 1, 2017
Besides economic and welfare aspects, breeding might also reduce environmental impacts, such as use of water or land, or emission of CO2, methane or ammonia Thus, environmental impacts have received increasing attention in the definition of breeding goals. Environmental impacts occur not only at the farm level, but also during the production of farm inputs (upstream processes), such as feed production, or during processing or selling of animal products (downstream processes). A method commonly used to assess the environmental impact of livestock or fish production is life cycle assessment (LCA). LCA is a standardized method that estimates the environmental impacts of a product during the entire life cycle, or in other words, throughout the production chain. LCA links the environmental impacts along the production chain to the main output of that system, i.e. also referred to as the functional unit Functional units in LCAs of food products are, for example, kg of fat-and-protein-corrected milk, kg of grain or meat produced (de Vries and de Boer, 2010) or ton of fresh fish produced Two types of environmental impacts are distinguished in a LCA: the use of natural resources (e.g. land, fossil energy, or water) required for the production of a functional unit and the corresponding emission of pollutants (e.g. ammonia, nitrate or methane) from a given production system. Use of resources or emission of pollutants can contribute to different environmental problems (referred to as impact categories), such as fossil energy use, acidification, eutrophication of or climate change (de Vries and de Boer, 2010). For example, to assess the impact of a production system on climate change, emissions of the main greenhouse gases in food production (i.e. carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)) are summed along the chain based on their equivalence factor in terms of CO2 equivalent (CO2-eq, 100-year time horizon). Because of its capacity to include environmental impacts at every step of the production system, LCA has started to be used to investigate the environmental effects of genetic improvement in livestock Similar to economic values, environmental values represent the change in environmental impacts (i.e. climate change) after genetic improvement of one trait, while keeping the other traits constant. The purpose of the bioeconomic model developed by
- Research Article
22
- 10.3389/fvets.2020.00651
- Sep 28, 2020
- Frontiers in Veterinary Science
Lamb meat production provides vital landscape-management and ecosystem services; however, ruminant farming produces a considerable share of the world's greenhouse gas emissions. To measure and compare the advantages and disadvantages of the intensification of livestock farming, an integrative analysis was conducted in this study by combining environmental impact analysis and animal welfare assessment. This approach is the first of its kind and is the innovative aspect of this paper. The methodology of Life Cycle Assessment (LCA) entails the holistic analysis of various impact categories and the associated emission quantities of products, services, and resources over their life cycle, including resource extraction and processing, production processes, transport, usage, and the end of life. The outlines of LCA are standardized in DIN EN ISO 14040/14044. To assess the environmental impacts of the production of lamb meat in northern Italy, two case studies were undertaken using the LCA software GaBi. The analysis is based on primary data from two sheep-breeding systems (semi-extensive and semi-intensive in alpine and continental bioregions, respectively) combined with inventory data from the GaBi database and data from the literature. The assessment was conducted for the functional unit of 1 kg of lamb meat and focuses on the impact categories global warming potential, acidification potential, and eutrophication potential. For an overall evaluation of the supply chain, we have also considered a parameter indicating animal welfare, in keeping with consumer concerns, employing an analysis of chronic stress as shown by cortisol accumulation. The goal is to derive models and recommendations for an efficient, more sustainable use of resources without compromising animal welfare, meat quality, and competitiveness. The aim of this study is to provide a standard for individualized sustainability analyses for European lamb production systems in the future. From the LCA perspective, the more intensive case-study farm showed a lower impact in global impact factors and a higher impact in local impact categories in comparison with the more extensively run farm that was studied. From the animal welfare perspective, lower amounts of the stress hormone cortisol were found on the extensively managed case-study farm.
- Research Article
2
- 10.1016/j.ekir.2025.10.019
- Oct 30, 2025
- Kidney International Reports
IntroductionData reporting the environmental impact of the overall chronic kidney disease (CKD) care pathway are limited.MethodsWe performed a life cycle assessment (LCA) of CKD stages 1 to 5, with a primary focus on greenhouse gas (GHG) emissions and a secondary aim of quantifying broader environmental effects. The main scope estimated annual environmental impacts in the USA and UK, both per patient and for the total CKD population, with 8 additional countries included in exploratory analyses. Model inputs (annual health care resource use; travel distance; energy mix; and heating, cooling, and lighting requirements) were country-specific, where available. Environmental impacts by stage were calculated using the ReCiPe impact assessment method.ResultsIn the USA and UK, annual per-patient GHG emissions increased with CKD stage, from 1.9 to 7.8 tonnes and 0.4 to 5.1 tonnes of carbon dioxide equivalents (CO2e), respectively, with similar trends for other environmental impacts. Total annual GHG emissions were 30.6 and 1.8 megatonnes CO2e in the USA and UK, respectively, with stage 3 contributing the greatest proportion. Hospitalization drove emissions for stages 1 to 4, for stage 5 on supportive care, and for the prevalent transplant population. For patients receiving kidney replacement therapy (KRT), choice of modality drove GHG emissions. Although only 6.7% of the US CKD population and 2.6% of the UK population received KRT, this accounted for 15.2% and 11.1% of national CKD emissions, respectively, largely from thrice-weekly in-center hemodialysis (HD).ConclusionThis research provides insights into the overall environmental burden of CKD and impact hotspots, enabling the development of targeted interventions that reduce emissions.
- Research Article
15
- 10.1186/1745-6215-14-333
- Jan 1, 2013
- Trials
BackgroundEstablished on 1 June 2005, the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) is the largest clinical trial registry in Japan, and joined the World Health Organization (WHO) registry network in October 2008. Our aim was to understand the registration trend and overall characteristics of Japan domestic, academic (non-industry-funded) clinical trials, which constitute the main body of registrations in UMIN-CTR. In addition, we aimed to investigate the accessibility of clinical trials in UMIN-CTR to people worldwide, as well as the accessibility of clinical trials conducted in Japan but registered abroad to Japanese people in the Japanese language.MethodsWe obtained the data for registrations in UMIN-CTR from the UMIN Center, and extracted Japan domestic, academic clinical trials to analyze their registration trend and overall characteristics. We also investigated how many of the trials registered in UMIN-CTR could be accessed from the International Clinical Trials Registry Platform (ICTRP). Finally, we searched ClinicalTrials.gov for all clinical trials conducted in Japan and investigated how many of them were also registered in Japanese registries. All of the above analyses included clinical trials registered from 2 June 2005 to 1 June 2010.ResultsDuring the period examined, the registration trend showed an obvious peak around September 2005 and rapid growth from April 2009. Of the registered trials, 46.4% adopted a single-arm design, 34.5% used an active control, only 10.9% were disclosed before trial commencement, and 90.0% did not publish any results. Overall, 3,063 of 3,064 clinical trials registered in UMIN-CTR could be accessed from ICTRP. Only 8.7% of all clinical trials conducted in Japan and registered in ClinicalTrials.gov were also registered in Japanese registries.ConclusionsThe International Committee of Medical Journal Editors (ICMJE) announcements about clinical trial registration and the Ethical Guidelines for Clinical Research published by the Japanese government are considered to have promoted clinical trial registration in UMIN-CTR. However, problems associated with trial design, retrospective registration, and publication of trial results need to be addressed in future. Almost all clinical trials registered in UMIN-CTR are accessible to people worldwide through ICTRP. However, many trials conducted in Japan but registered abroad cannot be accessed from Japanese registries in Japanese.