Study design: what's in a name?

The name of the study should properly reflect the actual conduct and analysis of the study. This short paper provides guidance on how to properly name the study design. The first distinction is between a trial (intervention given to patients to study its effect) and an observational study. For observational studies, it should further be decided whether it is cross-sectional or whether follow-up time is taken into account (cohort or case-control study). The distinction prospective-retrospective has two disadvantages: prospective is often seen as marker of higher quality, which is not necessarily true; there is no unifying definition that makes a proper distinction between retrospective and prospective possible.

Characteristics of registered clinical trials assessing treatments for COVID-19: a cross-sectional analysis

OBJECTIVES

The coronavirus disease 2019 (COVID-19) pandemic has prompted many initiatives to identify safe and efficacious treatments, yet little is known regarding where early efforts have focused. We aimed to characterise registered clinical trials assessing drugs or plasma treatments for COVID-19.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional analysis of clinical trials for the treatment of COVID-19 that were registered in the USA or in countries contributing to the WHO's International Clinical Trials Registry Platform. Relevant trial entries of drugs or plasma were downloaded on 26 March 2020, deduplicated, verified with reviews of major medical journals and WHO websites and independently analysed by two reviewers.

MAIN OUTCOMES

Trial intervention, sponsorship, critical design elements and specified outcomes RESULTS: Overall, 201 clinical trials were registered for testing the therapeutic benefits of 92 drugs or plasma, including 64 in monotherapy and 28 different combinations. Only eight (8.7%) products or combinations involved new molecular entities. The other test therapies had a wide range of prior medical uses, including as antivirals, antimalarials, immunosuppressants and oncology treatments. In 152 trials (75.7%), patients were randomised to treatment or comparator, including 55 trials with some form of blinding and 97 open-label studies. The 49 (24.4%) of trials without a randomised design included 29 single armed studies and 20 trials with some comparison group. Most trial designs featured multiple endpoints. Clinical endpoints were identified in 134 (66.7%) of trials and included COVID-19 symptoms, death, recovery, required intensive care and hospital discharge. Clinical scales were being used in 33 (16.4%) trials, most often measures of oxygenation and critical illness. Surrogate endpoints or biomarkers were studied in 88 (42.3%) of trials, primarily assays of viral load. Although the trials were initiated in more than 17 countries or regions, 100 (49.8%) were registered in China and 78 (37.8%) in the USA. Registered trials increased rapidly, with the number of registered trials doubling from 1 March to 26 March 2020.

CONCLUSIONS

While accelerating morbidity and mortality from the COVID-19 pandemic has been paralleled by early and rapid clinical investigation, many trials lack features to optimise their scientific value. Global coordination and increased funding of high-quality research may help to maximise scientific progress in rapidly discovering safe and effective treatments.

Reporting of randomized factorial trials was frequently inadequate

OBJECTIVES

Factorial designs can allow efficient evaluation of multiple treatments within a single trial. We evaluated the design, analysis, and reporting in a sample of factorial trials.

STUDY DESIGN AND SETTING

Review of 2 × 2 factorial trials evaluating health-related interventions and outcomes in humans. Using Medline, we identified articles published between January 2015 and March 2018. We randomly selected 100 articles for inclusion.

RESULTS

Most trials (78%) did not provide a rationale for using a factorial design. Only 63 trials (63%) assessed the interaction for the primary outcome, and 39/63 (62%) made a further assessment for at least one secondary outcome. 12/63 trials (19%) identified a significant interaction for the primary outcome and 16/39 trials (41%) for at least one secondary outcome. Inappropriate methods of analysis to protect against potential negative effects from interactions were common, with 18 trials (18%) choosing the analysis method based on a preliminary test for interaction, and 13% (n = 10/75) of those conducting a factorial analysis including an interaction term in the model.

CONCLUSION

Reporting of factorial trials was often suboptimal, and assessment of interactions was poor. Investigators often used inappropriate methods of analysis to try to protect against adverse effects of interactions.

Analysis of registered cancer clinical trials in Latin America and the Caribbean, 2007-2013

Objective To characterize cancer clinical trials in Latin America and the Caribbean (LAC), with a focus on registration and enrollment trends. Methods Data were collected from 1 285 active cancer clinical trials registered up until 31 May 2014 in the World Health Organization's International Clinical Trial Registry Platform (ICTRP). The trials were categorized by six characteristics of the continuum of cancer control and care: 1) control and planning, 2) prevention, 3) detection and screening, 4) diagnosis, 5) treatment, and 6) survivorship and palliative care. The search strategy protocol included the use of optimized keywords combined with the names of the 43 countries selected for a descriptive analysis. Results A total of 973 registered and 972 enrolled cancer clinical trials between January 2007 and December 2013 were identified. Trends of growth were observed for both registration and enrollment of cancer treatment clinical trials; for other types of cancer clinical trials, trends for registration and enrollment varied in direction. Conclusions Growth trends in the registration of cancer treatment clinical trials indicate incremental adherence to cancer research reporting and improvements in cancer research transparency. The higher proportion of cancer treatment trials versus other types of cancer clinical trials indicates an imbalance in cancer research in the LAC region and suggests the need for more funding and incentives for other areas of research in order to achieve a more comprehensive approach to gaining knowledge on cancer issues.

Indirect Comparisons and Network Meta-Analyses

BACKGROUND

Systematic reviews provide a structured summary of the results of trials that have been carried out on any particular subject. If the data from multiple trials are sufficiently homogenous, a meta-analysis can be performed to calculate pooled effect estimates. Traditional meta-analysis involves groups of trials that compare the same two interventions directly (head to head). Lately, however, indirect comparisons and network metaanalyses have become increasingly common.

METHODS

Various methods of indirect comparison and network meta-analysis are presented and discussed on the basis of a selective review of the literature. The main assumptions and requirements of these methods are described, and a checklist is provided as an aid to the evaluation of published indirect comparisons and network meta-analyses.

RESULTS

When no head-to-head trials of two interventions are available, indirect comparisons and network metaanalyses enable the estimation of effects as well as the simultaneous analysis of networks involving more than two interventions. Network meta-analyses and indirect comparisons can only be useful if the trial or patient characteristics are similar and the observed effects are sufficiently homogeneous. Moreover, there should be no major discrepancy between the direct and indirect evidence. If trials are available that compare each of two treatments against a third one, but not against each other, then the third intervention can be used as a common comparator to enable a comparison of the other two.

CONCLUSION

Indirect comparisons and network metaanalyses are an important further development of traditional meta-analysis. Clear and detailed documentation is needed so that findings obtained by these new methods can be reliably judged.

Clinical Outcome Assessments: Conceptual Foundation-Report of the ISPOR Clinical Outcomes Assessment - Emerging Good Practices for Outcomes Research Task Force

An outcome assessment, the patient assessment used in an endpoint, is the measuring instrument that provides a rating or score (categorical or continuous) that is intended to represent some aspect of the patient's health status. Outcome assessments are used to define efficacy endpoints when developing a therapy for a disease or condition. Most efficacy endpoints are based on specified clinical assessments of patients. When clinical assessments are used as clinical trial outcomes, they are called clinical outcome assessments (COAs). COAs include any assessment that may be influenced by human choices, judgment, or motivation. COAs must be well-defined and possess adequate measurement properties to demonstrate (directly or indirectly) the benefits of a treatment. In contrast, a biomarker assessment is one that is subject to little, if any, patient motivational or rater judgmental influence. This is the first of two reports by the ISPOR Clinical Outcomes Assessment - Emerging Good Practices for Outcomes Research Task Force. This report provides foundational definitions important for an understanding of COA measurement principles. The foundation provided in this report includes what it means to demonstrate a beneficial effect, how assessments of patients relate to the objective of showing a treatment's benefit, and how these assessments are used in clinical trial endpoints. In addition, this report describes intrinsic attributes of patient assessments and clinical trial factors that can affect the properties of the measurements. These factors should be considered when developing or refining assessments. These considerations will aid investigators designing trials in their choice of using an existing assessment or developing a new outcome assessment. Although the focus of this report is on the development of a new COA to define endpoints in a clinical trial, these principles may be applied more generally. A critical element in appraising or developing a COA is to describe the treatment's intended benefit as an effect on a clearly identified aspect of how a patient feels or functions. This aspect must have importance to the patient and be part of the patient's typical life. This meaningful health aspect can be measured directly or measured indirectly when it is impractical to evaluate it directly or when it is difficult to measure. For indirect measurement, a concept of interest (COI) can be identified. The COI must be related to how a patient feels or functions. Procedures are then developed to measure the COI. The relationship of these measurements with how a patient feels or functions in the intended setting and manner of use of the COA (the context of use) could then be defined. A COA has identifiable attributes or characteristics that affect the measurement properties of the COA when used in endpoints. One of these features is whether judgment can influence the measurement, and if so, whose judgment. This attribute defines four categories of COAs: patient reported outcomes, clinician reported outcomes, observer reported outcomes, and performance outcomes. A full description as well as explanation of other important COA features is included in this report. The information in this report should aid in the development, refinement, and standardization of COAs, and, ultimately, improve their measurement properties.

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.

Automatic information timeliness assessment of diabetes web sites by evidence based medicine

Studies on health domain have shown that health websites provide imperfect information and give recommendations which are not up to date with the recent literature even when their last modified dates are quite recent. In this paper, we propose a framework which assesses the timeliness of the content of health websites automatically by evidence based medicine. Our aim is to assess the accordance of website contents with the current literature and information timeliness disregarding the update time stated on the websites. The proposed method is based on automatic term recognition, relevance feedback and information retrieval techniques in order to generate time-aware structured queries. We tested the framework on diabetes health web sites which were archived between 2006 and 2013 by Archive-it using American Diabetes Association's (ADA) guidelines. The results showed that the proposed framework achieves 65% and 77% accuracy in detecting the timeliness of the web content according to years and pre-determined time intervals respectively. Information seekers and web site owners may benefit from the proposed framework in finding relevant and up-to-date diabetes web sites.

Effective intervention or child's play? A review of video games for diabetes education

BACKGROUND

The purpose of this study is (1) to identify diabetes education video games and pilot studies in the literature, (2) to review themes in diabetes video game design and evaluation, and (3) to evaluate the potential role of educational video games in diabetes self-management education.

METHODS

Studies were systematically identified for inclusion from Medline, Web of Science, CINAHL, EMBASE, Psychinfo, IEEE Xplore, and ACM Digital Library. Features of each video game intervention were reviewed and coded based on an existing taxonomy of diabetes interventions framework.

RESULTS

Nine studies featuring 11 video games for diabetes care were identified. Video games for diabetes have typically targeted children with type 1 diabetes mellitus and used situation problem-solving methods to teach diet, exercise, self-monitored blood glucose, and medication adherence. Evaluations have shown positive outcomes in knowledge, disease management adherence, and clinical outcomes.

CONCLUSIONS

Video games for diabetes education show potential as effective educational interventions. Yet we found that improvements are needed in expanding the target audience, tailoring the intervention, and using theoretical frameworks. In the future, the reach and effectiveness of educational video games for diabetes education could be improved by expanding the target audience beyond juvenile type 1 diabetes mellitus, the use of tailoring, and increased use of theoretical frameworks.

Translating stem cell research: challenges at the research frontier

This paper will address the translation of basic stem cell research into clinical research. While "stem cell" trials are sometimes used to describe established practices of bone marrow transplantation or transplantation of primary cells derived from bone marrow, for the purposes of this paper, I am primarily focusing on stem cell trials which are far less established, including use of hESC derived stem cells. The central ethical challenges in stem cell clinical trials arise in frontier research, not in standard, well-established areas of research.

Development and evaluation of a study design typology for human research

A systematic classification of study designs would be useful for researchers, systematic reviewers, readers, and research administrators, among others. As part of the Human Studies Database Project, we developed the Study Design Typology to standardize the classification of study designs in human research. We then performed a multiple observer masked evaluation of active research protocols in four institutions according to a standardized protocol. Thirty-five protocols were classified by three reviewers each into one of nine high-level study designs for interventional and observational research (e.g., N-of-1, Parallel Group, Case Crossover). Rater classification agreement was moderately high for the 35 protocols (Fleiss' kappa = 0.442) and higher still for the 23 quantitative studies (Fleiss' kappa = 0.463). We conclude that our typology shows initial promise for reliably distinguishing study design types for quantitative human research.

Natural language processing of clinical trial announcements: exploratory-study of building an automated screening application

Clinical trials are important for the advancement of medical research. Despite of the benefits clinical trial enrollment is low. We study the feasibility of using NLP to assist with automatic eligibility screening by extracting medical diagnoses from the inclusion and exclusion criteria of cancer clinical trial announcements posted on the internet. We compare the performances of the system versus an oncologist.

An ontology-based architecture for integration of clinical trials management applications

Management of complex clinical trials involves coordinated-use of a myriad of software applications by trial personnel. The applications typically use distinct knowledge representations and generate enormous amount of information during the course of a trial. It becomes vital that the applications exchange trial semantics in order for efficient management of the trials and subsequent analysis of clinical trial data. Existing model-based frameworks do not address the requirements of semantic integration of heterogeneous applications. We have built an ontology-based architecture to support interoperation of clinical trial software applications. Central to our approach is a suite of clinical trial ontologies, which we call Epoch, that define the vocabulary and semantics necessary to represent information on clinical trials. We are continuing to demonstrate and validate our approach with different clinical trials management applications and with growing number of clinical trials.

Nouvelle législation portant sur les soins courants: rappel des difficultés passées

OBJECTIVE

The regulatory framework of clinical research in France was recently modified substantially, in part to transpose into French law directive 2001/20/EC of the European Parliament and Council, which concerns only drug trials. The revision also covered research on "human beings" (Public Health L. 2004-806, 2006-450), on biological samples (revision of bioethics, L. 2004-800) and on data (the so-called CNIL act, L. 2004-801). The value of this set of texts (statutes, decrees, and regulations) is that it diversifies and clarifies the different forms of clinical research.

METHODS

This article describes the painful progression of important public health studies, most often with "academic" sponsors.

RESULTS

The 5 studies described here managed to overcome a variety of obstacles posed by the pre-2004 regulations.

COMMENTS

To understand the new provisions, it is useful to recall the difficulties, imprecision and inaptness of the earlier regulations.

Methodology of superiority vs. equivalence trials and non-inferiority trials

The randomized clinical trial (RCT) is generally accepted as the best method of comparing effects of therapies. Most often the aim of an RCT is to show that a new therapy is superior to an established therapy or placebo, i.e. they are planned and performed as superiority trials. Sometimes the aim of an RCT is just to show that a new therapy is not superior but equivalent to or not inferior to an established therapy, i.e. they are planned and performed as equivalence trials or non-inferiority trials. Since the types of trials have different aims, they differ significantly in various methodological aspects. The awareness of the methodological differences is generally quite limited. This paper reviews the methodology of these types of trials with special reference to differences in respect to planning, performance, analysis and reporting of the trial. In this context the relevant basal statistical concepts are reviewed. Some of the important points are illustrated by examples.

The research misconception

Recently, several researchers and philosophers argued that clinical research trials are not therapy. Their position is based on foundational research ethics documents, such as the Belmont Report, on conceptual analysis, and on the general way clinical trials are conducted. After examining and rejecting these arguments, we claim that good research is consistent with good therapy; that often trials are good therapy; and that a blanket attack on clinical trials as non-therapeutic creates a research misconception. This misconception is potentially harmful because it could weaken trial recruitment, could adversely affect funding for trials, and could overturn needed moral safeguards on therapeutic trials. Our more careful and accurate analysis of the nature of clinical trials can avoid such problems.

[Defining trials of medicinal products according to the revised Dutch Medical Research in Human Subjects Act (WMO)]

The revised Dutch Medical Research in Human Subjects Act (WMO), which implements the European directive regarding 'good clinical practice in the conduct of clinical trials on medicinal products for human use' (2001/20/EC), became effective on March 1, 2006. The revision places additional requirements on trials of medicinal products. Whether a trial should be regarded as a trial of a medicinal product is therefore an important question. The law does not provide adequate guidance for the classification of trials in which biological samples are collected, e.g. for genomic, proteomic or pharmacokinetic studies, while a medicinal product is given for a registered indication. Classifying these types of trials as trials of medicinal products does not enhance the safety of the participants. Therefore, these studies should not be considered as trials of medicinal products to avoid the increased administrative burden required by the revised WMO.

Outcome of paediatric convulsive status epilepticus: a systematic review

We did a systematic review on the outcome of paediatric convulsive status epilepticus (CSE) and investigated the role of biological and non-biological variables in reported outcomes. The methodological quality of the 63 studies that met our inclusion criteria was assessed. Study design, type of study, and length of follow-up influenced the outcome. The studies with highest methodological quality are associated with better outcome: short-term mortality between 2.7% and 5.2% and morbidity other than epilepsy less than 15%. The incidence of subsequent epilepsy is not increased after cryptogenic CSE. Causal factor is the main determinant of outcome and the effect of age or duration is difficult to separate from the underlying cause. The risk of sequelae in unprovoked and febrile CSE is low. There is some evidence that CSE, especially febrile CSE, might cause hippocampal injury, although its role in the development of mesial temporal sclerosis is unknown.

Reducing disparities in the burden of cancer: the role of patient navigators

Many racial and ethnic minority patients with cancer face barriers related to access to health care and information. Patient navigators, say the authors, could help to overcome these barriers.

Coverage of clinical trials tasks in existing ontologies

Clinical research trials involve multiple, often simultaneous processes and corresponding data that collectively involve a diverse group of stakeholders. As efforts are ongoing to enable computable clinical trials and harmonize clinical research data, an ontology targeting the domain of clinical research is essential. As part of a larger project to develop a Clinical Trials scheduling and tracking application, the domain coverage of the UMLS and two component ontologies- SNOMED CT, and the NCI Thesaurus-was evaluated in the context of common clinical trial tasks and events. In total, 102 unique activities were abstracted from 20 protocols, representing a variety of domains, and manually mapped to the target ontologies. Coverage ranged from 84% for UMLS to 32% for the NCI Thesaurus.

Consensus-based construction of a taxonomy of clinical trial tasks

The use of conceptual knowledge collections, such as taxonomies, is prevalent throughout the biomedical domain. Tools and methods to enable the computational representation of such knowledge collections are well established. However, methods for the design and construction of knowledge collections are varied and often rely on the judgments of a single, or small group of, specially trained knowledge engineers. This poster will report on a novel multi-expert consensus-based approach to the development of taxonomies that has been applied to the development of a taxonomy of clinical trial tasks and events.

Pharmacogenetics-based therapeutic recommendations--ready for clinical practice?

Although considerable progress has been made in basic pharmacogenetic research, less has been demonstrated in the application of pharmacogenetics (PGx)-based diagnostics to drug development and in clinical practice. There are drugs that are currently used in the clinic for which individualized therapy could be beneficial based on PGx data. However, specific, actionable recommendations on how to implement individualized therapy--particularly with respect to dosage--still have to be developed. Moreover, to apply PGx efficiently in clinical drug development, and later in drug therapy, study designs and the generation and handling of PGx data need to become more standardized. Here, we argue for the development of concise guidelines for implementation of PGx analyses in drug development and therapy.

The ultimate model organism: progress in experimental medicine

Experimental medicine is the use of innovative measurements, models and designs in studying human subjects for establishing proof of mechanism and concept of new drugs, for exploring the potential for market differentiation for successful drug candidates, and for efficiently terminating the development of unsuccessful ones. Humans are the ultimate 'model' because of the uncertain validity and efficacy of novel targets and drug candidates that emerge from genomics, combinatorial chemistry and high-throughput screening and the use of poorly predictive preclinical models. The in-depth investigation of the effects of drugs and the nature of disease progression is becoming ever more feasible because of advances in clinical biomarkers.

When is a clinical study non-commercial?

A non-commercial study is a research project not aiming at the protection of a commercial institution's interests. The classification of a clinical study as non-commercial or commercial makes sense and is important especially for clinical research teams, ethics committees and hospital owners because of relevant differences in the image and cost fields. The support of non-commercial studies by commercial institutions like pharmaceutical companies is permissible, unless it is tied to conditions impairing impartiality in respect of design, publication of study results or ownership of the assessed data. Specific relationships between the investigator and a company of the health industry potentially profiting from the study results (e.g. major share holdings or financial dependences) favour the classification of a study as commercial. The reliable classification of a study as non-commercial is only possible if all aids and grants, all conflicts of interest and special agreements are disclosed.

Macro trends in pharmaceutical innovation

Critics decry the lack of 'truly innovative' new medicines and question the role of the pharmaceutical industry in creating the few that are developed. Is this an accurate portrayal of the state of pharmaceutical innovation? Does major pharma still innovate? If so, how? Must the industry innovate to survive? These and related issues are discussed.

Clinical trials in cancer. Part I. Biomedical, complementary, and alternative medicine: finding active trials and results of closed trials

Most cancer CAM clinical trials are treatment or supportive care trials in phase I, II, or III status. A recent search showed that, at present, a very limited number of retrievable pharmaceutical- or industry-sponsored cancer CAM clinical trials is listed in publicly accessible databases. Two databases, Center Watch and Trial Check, focus on industry, healthcare providers, and patient advocate groups and have fees or limited access. As more clinical trials are imported from NLM's Clinical Trials.gov to NCI's PDQ database, more cancer CAM trials will be accessible and free to the public. Published results from clinical trials are available in multiple locations and retrievable with advanced searching but remain of limited access to most of the public because of academic or hospital library subscription services. All cancer clinical trial results are not likely to be housed in one location (either via database or in print); thus, cancer CAM clinical trial results likely will not be either. Because PDQ currently is the central location for cancer CAM clinical trial listings in the United States, the database should be expanded to include published results that are retrievable by healthcare professionals and the lay public free of charge. In clinical and research roles, oncology nurses are compelled to keep abreast of advances in cancer care, especially in the realm of cancer clinical trials. Keeping abreast of results of cancer CAM clinical trials is vital for oncology nurses in patient education, advocacy, and advancement of evidence-based practice.

Identification and assessment of ongoing trials in health technology assessment reviews

OBJECTIVES

To assess the importance of ongoing trials in health technology assessment reviews (HTARs) for the National Institute for Clinical Excellence and to provide practical recommendations for identifying ongoing trials and assessing their possible impact.

DATA SOURCES

Electronic databases.

REVIEW METHODS

Ongoing trials (or trials in progress) were defined as any trials that have started but where the results are not yet available or only interim results are available for HTARs. This methodological review included: (1) an assessment of ongoing trials in HTARs completed by the end of August 2002, (2) a survey and assessment of trial registers and other sources of ongoing trials and (3) a summary and assessment of available methods for assessing the possible impacts of ongoing trials.

RESULTS

The identification of ongoing trials is a common phenomenon in reviews of health technology assessment. Twenty-three of the 32 HTARs identified one or more ongoing trials and in eight of these the information on identified ongoing trials was not considered in the evidence synthesis and research recommendations. All but one HTAR that considered the potential impact of ongoing trials adopted a narrative approach. Trial registers and grey literature are important sources of information on ongoing trials. All 32 HTARs explicitly or implicitly searched for unpublished studies, and/or ongoing trials and/or grey literature and trial registers. The assessment of six commonly used trial registers suggested that most registers provided sufficient information for reviewers to decide the relevance of identified ongoing trials. However, it is sometimes extremely difficult to know whether ongoing trials identified from different sources (registers) are the same trials or belong to the same multicentre trials. The ISRCTN (the International Standard Randomised Controlled Trial Number) is the most reliable system but it has not been widely adopted. The qualitative assessment of ongoing trials compared major features of completed and ongoing trials, providing information about the possible impact of ongoing trials in terms of relevance, validity, reliability and generalisability. Quantitative methods to assess the impact of ongoing trials include cumulative meta-analysis related methods, fail-safe N, Bayesian data monitoring, and Bayesian interim predictions. The most useful method may be the Bayesian predictive probability, which estimates predictive probabilities for any possible values of treatment effect. A case study indicated that the appropriate use of quantitative methods would strengthen findings from narrative assessment of possible impact of ongoing trials.

CONCLUSIONS

Identification of ongoing trials is common in HTARs. Searching for ongoing trials in effectiveness reviews should be more thorough and explicit. Conversely, primary researchers, in particular those working with in multicentre trials, should label ongoing trials more clearly, preferably by ISRCTN. Qualitative assessment of identified ongoing trials is crucial and informative. Available quantitative methods could be used to strengthen findings from narrative assessment, although further research and more empirical examples are required. Information from ongoing trials may contribute to syntheses of results, conclusions and recommendations for future research. Future research is suggested into the identification and assessment of ongoing trials in other systematic reviews of effectiveness of health care interventions; existing and new methods for incorporating information on ongoing trials; comparing estimated impacts with the actual results of ongoing trials; and to incorporate findings from the assessment of ongoing trials into decision models.

Coding for clinical trials

Although CMS reimburses for routine care associated with clinical trials, it is essential that the correct diagnosis code, modifier, and, where necessary, HCPCS Level II procedure code be assigned to accurately report these qualifying trial services. Remember that not all insurance payors will provide reimbursement for services rendered as part of a clinical trial, and individual payor policies should be obtained and followed for these services.

The classic caries clinical trial: constraints and opportunities

The history of clinical trials would include events in 1747 on board the Salisbury, a British Navy vessel at sea with 12 seamen critically ill with scurvy. Involving these 12 sailors in a study, an officer on board by the name of Lind evaluated six potential treatments for scurvy, and rapidly reached the conclusion that daily consumption of citrus fruits returned the men fit for duty in approximately six days (Bull, 1959). The concept of experimental randomization was first developed by Sir R.A. Fisher (1925, 1926), and the method was introduced to medical research via a study of tuberculosis treatment by Amberson and co-workers (1931), who randomized 24 TB patients into two groups, one to receive the experimental therapy, the other serving as the control. Amberson et al. also incorporated the concept of blinding into their study. Sir Austin Bradford Hill codified and built on the principles of scientific experimentation developed by Fisher, and introduced the use of random numbers in the allocation of patients in the British Medical Research Council (1948) study of the effect of streptomycin in the treatment of tuberculosis (Daniels and Hill, 1952; Hill, 1952). The first applications of clinical trial methodology for testing interventions on dental, oral, and maxillofacial diseases and conditions are more difficult to determine. For dental caries prevention, however, Chilton and Fertig (1958) and Slack and Martin (1964) were certainly among the early caries clinical trial pioneers. As clinical trials have come into the mainstream of clinical research in medicine and dentistry, a great deal of developmental work has focused on their methodological enhancement. The most successful of these efforts have come from fruitful, ongoing collaborations among clinician investigators, biostatisticians, data management specialists, biomedical ethicists, and others with an academic interest in clinical trial design and utilization. During the past 25 years, the emergence of systematic reviews and the evidence-based medicine (EBM) movement have also contributed significantly to the increasing reliance on randomized clinical trial outcomes for the advancement of better clinical practice (Richards et al., 1997; Straus and Sackett, 1998; www.cochrane.org/cochrane/ccbroch.htm#BDL, 2002).

Novel designs for multi-arm clinical trials with survival outcomes with an application in ovarian cancer

With the increasing pace of drug development, it is not unusual for several promising treatment regimens to be ready simultaneously for testing in a randomized phase III setting. Various limiting factors, including the time needed to transfer research results to clinical practice and a narrow 'window of opportunity', may make it unfeasible to perform trials to test such regimens sequentially against a control treatment in a traditional two-arm parallel group design. We present an approach to trial design based on eliminating inferior contenders at an early stage, allowing through to a second stage only treatments that show a predefined degree of advantage against a control treatment. The first stage of testing utilizes a marker known to be a valid intermediate outcome measure or surrogate for the definitive outcome. The experimental arms are compared pairwise with control according to this intermediate outcome measure. Arms that survive the comparison enter a second stage of patient accrual culminating in comparisons against control on the outcome measure of primary interest. We show how the design may be realized in practice by considering hypothetically distinct trials at stages 1 and 2, each with their own operating characteristics. The overall operating characteristics are computed from the stage 1 and 2 size and power and the correlation between the treatment effects on the intermediate and primary outcome measures according to a bivariate Normal approximation. The correlation is estimated by bootstrapping individual patient data from previous trials. We illustrate the general approach in a design of a real trial of four new chemotherapy regimens for advanced ovarian cancer. The intermediate outcome measure is progression-free survival. An international randomized controlled trial using the new design is already under way.

Clinical development of therapeutic recombinant proteins

Only a small subset of the therapeutics that enter clinical studies will prove to be safe and effective in humans and gain approval for marketing. The success of the products and, by inference, the sponsoring companies can be measured by tracking advancement through the clinical phase and review transitions to marketing approval. To determine phase transition probabilities and approval success rates for recombinant protein (rDNA) therapeutics, the Tufts Center for the Study of Drug Development collected data for 271 rDNA therapeutics that entered clinical study between 1980 and 2002. The data were stratified into eight therapeutic categories. Approval success rates were calculated for rDNA therapeutics with two possible fates: (i) approval in any country and (ii) U.S. approval only. Global approval success rates ranged from 23% to 63%, and U.S. approval success rates ranged from 17% to 58%. Trends in clinical phase lengths over five time periods and an overview of the rDNA therapeutics currently under Food and Drug Administration review are discussed.

Assessment of analysis by gender in the Cochrane reviews as related to treatment of cardiovascular disease

BACKGROUND

Cardiovascular disease (CVD) is the leading killer of women in the United States, yet medical care is often based on evidence from clinical trials performed predominantly with men. Numerous studies show that CVD risk factors, clinical presentation, treatment, and treatment outcomes can vary between men and women.

METHODS

The Cochrane Library maintains a large database of critically appraised evidence including meta-analyses of clinical trials, called Systematic Reviews. There were 30 Systematic Reviews pertaining to the treatment of CVD published collectively by the Cochrane Heart Group, Hypertension Group, and Peripheral Vascular Diseases Groups at the time of our study. We examined these 30 Systematic Reviews and the great majority of the clinical trials used for their meta-analyses for inclusion of women and gender-based data analyses. Women comprised only 27% of the pooled population of 258 clinical trials.

RESULTS

Of those trials that included both men and women (n = 196), only 33% examined outcomes by gender. In trials that performed a gender-based analysis, 20% reported significant (p < 0.05) differences in cardiovascular-related outcomes by gender.

CONCLUSIONS

We conclude that (1) there are not enough large-scale clinical trials or meta-analyses concerning CVD in women to determine if their medical treatment should differ from that of men, (2) all clinical trials relating to CVD treatment should have significantly more female participants, and gender-based analyses should be performed, as currently recommended for National Institutes of Health (NIH)-sponsored research by the NIH Revitalization Act of 1993, and (3) the Cochrane Library would be a more useful tool for the evidence-based healthcare of women if the Systematic Reviews used all available gender-specific information in their analyses.