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At least 127 records · Page 7Linked to original sources
PubMed2000

Evaluating the financial impact of clinical trials in oncology: results from a pilot study from the Association of American Cancer Institutes/Northwestern University clinical trials costs and charges project.

PURPOSE: Medical care for clinical trials is often not reimbursed by insurers, primarily because of concern that medical care as part of clinical trials is expensive and not part of standard medical practice. In June 2000, President Clinton ordered Medicare to reimburse for medical care expenses incurred as part of cancer clinical trials, although many private insurers are concerned about the expense of this effort. To inform this policy debate, the costs and charges of care for patients on clinical trials are being evaluated. In this Association of American Cancer Institutes (AACI) Clinical Trials Costs and Charges pilot study, we describe the results and operational considerations of one of the first completed multisite economic analyses of clinical trials. METHODS: Our pilot effort included assessment of total direct medical charges for 6 months of care for 35 case patients who received care on phase II clinical trials and for 35 matched controls (based on age, sex, disease, stage, and treatment period) at five AACI member cancer centers. Charge data were obtained for hospital and ancillary services from automated claims files at individual study institutions. The analyses were based on the perspective of a third-party payer. RESULTS: The mean age of the phase II clinical trial patients was 58.3 years versus 57.3 years for control patients. The study population included persons with cancer of the breast (n = 24), lung (n = 18), colon (n = 16), prostate (n = 4), and lymphoma (n = 8). The ratio of male-to-female patients was 3:4, with greater than 75% of patients having stage III to IV disease. Total mean charges for treatment from the time of study enrollment through 6 months were similar: $57,542 for clinical trial patients and $63,721 for control patients (1998 US$; P =.4) CONCLUSION: Multisite economic analyses of oncology clinical trials are in progress. Strategies that are not likely to overburden data managers and clinicians are possible to devise. However, these studies require careful planning and coordination among cancer center directors, finance department personnel, economists, and health services researchers.

Aged↗
PubMed2001

The process of clinical trials: a model for successful clinical trial participation.

PURPOSE/OBJECTIVES: To present barriers and strategies related to successful clinical trial participation and integrate them into a model for successful trial participation. DATA SOURCES: The proposed model was developed based on a literature review related to clinical trial participation, review of empirical studies related to clinical trials, and experiences with subject participation. DATA SYNTHESIS: Successful clinical trial participation depends on study design, participant factors, issues related to ethnic diversity, the informed consent process, and physician factors. CONCLUSIONS: Clinical trial participation is critical for all disciplines. However, nurses either are researchers or co-investigators with physicians on clinical trials, and it is critical for them to understand specific barriers and success strategies for patient participation. Future studies need to be conducted related to participation in nursing clinical trial research. These study results will facilitate successful nursing clinical trials. IMPLICATIONS FOR NURSING PRACTICE: This model can be used in implementation of clinical trials across disciplines prior to and during enrollment of patients into studies.

Clinical Trials as Topic↗
PubMed1986

Ethics and errors of clinical trials and the role and place of different types of trial.

Controlled clinical trials, usually carried out in a multicentre, randomized manner, have become fashionable and popular because they contribute to the general acceptance of the results, particularly when the difference between the treatment arms is small. The present book and the present introduction attempt to discuss when and how this form of trial is appropriate. It is recognized that the discussion may be one-sided in the sense that the undoubted and well-known merits of controlled clinical trials are not reiterated. The focus of the present discussion is on the scientific, practical and ethical problems inherent in such trials and on possibilities for improving their design. In the future clinical trials should be used with more restraint than hitherto. Phase I trials should replace inter-patient by intra-patient dose escalation in order to give each patient a chance to benefit from the treatment. Since such trials frequently cause discomfort, they should be limited to one centre at a time. The number of patients subjected to phase II trials can be appreciably reduced if reasonable statistical measures are taken, as proposed here, to optimize and minimize the trial. Phase III trials must improve the relevance of the questions asked, reporting of errors, patient information and statistical interpretation. They must be based on promising phase II studies with historical controls so that their efficacy is increased.

Antineoplastic Agents↗
PubMed1995

A trial bank model for the publication of clinical trials.

Clinical trials constitute one of the main sources of medical knowledge, yet trial reports are difficult to find, read, and apply to clinical care. Reasons for these difficulties include the lack of a common, standardized, structure for trial reports; the restricted length of reports; and limited computer support for use of the literature. We propose a new model of reporting clinical trials, in which trials are published as both prose commentary and as data in electronic "trial banks." The prose will allow authors to discuss their trials in writing; the electronic database will allow readers easy access to well-defined data about the trials. We are developing a formal conceptual model of the clinical trials domain for integrating the use of multiple trial banks. We will then focus on validating this conceptual model with clinical literature users.

Abstracting and Indexing↗
PubMed2004

Implementing the UK Medical Research Council (MRC) RT01 trial (ISRCTN 47772397): methods and practicalities of a randomised controlled trial of conformal radiotherapy in men with localised prostate cancer.

BACKGROUND AND PURPOSE: Radiotherapy is the most frequently used treatment for men with localised prostate cancer. Conformal radiotherapy (CFRT) is a relatively new development. MRC RT01 was set-up to explore optimum CFRT dose. PATIENTS AND METHODS: RT01 was an international multi-centre randomised controlled trial for men with T1b-T3a, N0, M0 prostate cancer that evolved from a single-centre pilot trial of similar design. All men received at least 3 months of pre-radiotherapy hormone treatment, before randomisation to standard (64 Gy) or high dose (74 Gy) radical CFRT. Accrual was completed in December 2001 with 843 men randomised from 25 centres in less than 4 years. RT01 has been a catalyst for implementing CFRT across UK. In addition to the Trial Management Group, independent Data Monitoring and Ethics Committee and independent Trial Steering Committee, a Quality of Life and Health Economics (QL/HE) group, a radiotherapy Quality Assurance (QA) Group and a Radiography Trial Implementation Group were set up. The QL/HE group ensured implementation, compliance, analysis and interpretation of the QL and HE data in the trial. The inauguration of QA and Radiography groups facilitated inter-centre collaboration. The QA Group ensured procedures were in place before and during trial participation, and monitored quality and consistency with systems including a physics questionnaire, a clinical examples exercise, a standard operating procedure document, designing and building a phantom, and convening a complications modelling subgroup. The Radiography group agreed and implemented technique improvements. RESULTS: More centres participated than initially predicted, enabling recruitment better than scheduled. The trial expedited the implementation of CFRT in many UK radiotherapy centres. Additionally, the QA and Radiography groups helped ensure smooth initiation and established consistency in planning, dosimetry and delivery of prostate CFRT services at participating UK centres. Considerable data has been collected; a series of papers will be produced, although mature clinical trial results are not anticipated until 2006-2008.

Humans↗
PubMed2002

Informing breast cancer patients about clinical trials: a randomized clinical trial of an educational booklet.

BACKGROUND: To evaluate the impact of an educational booklet on women's knowledge of and willingness to participate in a randomized clinical trial of treatment for breast cancer. MATERIALS AND METHODS: Women undergoing surgery for newly diagnosed early stage breast cancer were randomized to receive, or not, an information booklet explaining the need for and manner in which randomized trials are conducted. RESULTS: Eighty-three women with newly diagnosed early stage breast cancer completed a questionnaire assessing attitudes to random clinical trials (RCTs) and were randomized to receive usual information treatment options provided from their oncologist, or the educational booklet in addition to usual information from their oncologist (42 usual information, 41 booklet). Fewer women who received the clinical trials booklet (40% versus 47%) would consider participating in the hypothetical clinical trial (P = 0.6). Mean knowledge scores increased for both groups; moreover, women who did not receive the booklet showed similar improvements to women who received the booklet [mean difference 0.09, 95% confidence interval (CI) -0.66 to 0.83]. In a multivariate analysis women who would consider participating in the clinical trial were more anxious [odds ratio (OR) 5.9, P = 0.02] had involved lymph nodes (OR 5.8, P = 0.02) and were less influenced by negative aspects of clinical trials (OR 7.7, P = 0.0001). After adjustment for these variables women who received the educational booklet were significantly less likely to consider trial participation (OR 0.22, P = 0.05). CONCLUSIONS: Educating women about clinical trials in this manner appears ineffective in improving recruitment to RCTs. Women appear to be more influenced by their perception of risk than understanding. This finding has ethical implications for communication of information about RCTs.

Attitude to Health↗
PubMed2003

Advantage of single-trial models for response to selection in wheat breeding multi-environment trials.

An investigation was conducted to evaluate the impact of experimental designs and spatial analyses (single-trial models) of the response to selection for grain yield in the northern grains region of Australia (Queensland and northern New South Wales). Two sets of multi-environment experiments were considered. One set, based on 33 trials conducted from 1994 to 1996, was used to represent the testing system of the wheat breeding program and is referred to as the multi-environment trial (MET). The second set, based on 47 trials conducted from 1986 to 1993, sampled a more diverse set of years and management regimes and was used to represent the target population of environments (TPE). There were 18 genotypes in common between the MET and TPE sets of trials. From indirect selection theory, the phenotypic correlation coefficient between the MET and TPE single-trial adjusted genotype means [ r(p(MT))] was used to determine the effect of the single-trial model on the expected indirect response to selection for grain yield in the TPE based on selection in the MET. Five single-trial models were considered: randomised complete block (RCB), incomplete block (IB), spatial analysis (SS), spatial analysis with a measurement error (SSM) and a combination of spatial analysis and experimental design information to identify the preferred (PF) model. Bootstrap-resampling methodology was used to construct multiple MET data sets, ranging in size from 2 to 20 environments per MET sample. The size and environmental composition of the MET and the single-trial model influenced the r(p(MT)). On average, the PF model resulted in a higher r(p(MT)) than the IB, SS and SSM models, which were in turn superior to the RCB model for MET sizes based on fewer than ten environments. For METs based on ten or more environments, the r(p(MT)) was similar for all single-trial models.

Agriculture↗
PubMed2005

Task-switching with antisaccades versus no-go trials: a comparison of inter-trial effects.

Antisaccades involve the suppression of a pre-potent prosaccade and a vector inversion to generate the novel ocular motor response of looking away from the target. Antisaccades have also been found to prolong the latencies of saccades in upcoming trials, an effect that we attribute to a form of immediate plasticity in the ocular motor system. Our goal was to determine whether the inter-trial effects of antisaccades were similar to that of no-go trials, where subjects must suppress making a saccade when the target appears without substituting a novel ocular motor response. We tested 12 subjects with two different blocks of saccadic trials. In one, prosaccades randomly alternated with antisaccades. In the other, prosaccades alternated with no-go trials. We analyzed the error rates and latencies of prosaccades that followed antisaccades versus no-go trials, compared to repeated prosaccades, to determine if inter-trial effects were present for both types of responses that required prosaccade suppression. No-go responses increased the error rates of prosaccades in the following trial less than antisaccades did. However, no-go trials had the same effect on the latencies of upcoming prosaccades as antisaccades. The inhibitory effect that prolongs the latencies of prosaccades after antisaccades likely stems from the need to inhibit a prosaccade, a function that is also required in no-go trials. The greater impairment of prosaccade accuracy after an antisaccade may reflect either additional control mechanisms involved in vector inversion or a different form of inhibitory control that operates during antisaccades and not during no-go responses.

Adult↗
PubMed2006

Trial by trial effects in the antisaccade task.

The antisaccade task requires participants to inhibit the reflexive tendency to look at a sudden onset target and instead direct their gaze to the opposite hemifield. As such it provides a convenient tool with which to investigate the cognitive and neural systems that support goal-directed behaviour. Recent models of cognitive control suggest that antisaccade performance on a single trial should vary as a function of the outcome (correct antisaccade or erroneous prosaccade) of the previous trial. In addition, repetition priming effects suggest that the spatial location of the target on the previous trial may also influence current trial performance. Thus an analysis of contingency effects in antisaccade performance may provide new insights into the factors that influence the monitoring and modulation of the antisaccade task and other ongoing behaviours. Using a multilevel modelling analysis we explored previous trial effects on current trial performance in a large antisaccade dataset. We found (1) repetition priming effects following correct antisaccades; (2) contrary to models of cognitive control antisaccade error rates were increased on trials following an error, suggesting that failures to adequately maintain the task goal can persist across more than one trial; and (3) current trial latencies varied according to the previous trial outcome (correct antisaccade, slowly corrected error or rapidly corrected error). These results are discussed in terms of current models of antisaccade performance and cognitive control and further demonstrate the utility of multilevel modelling for analysing antisaccade data.

Adult↗
PubMed2006

The influence of trial-to-trial recalibration on sequential effects in cross-modality matching.

Sequential effects are examined in a cross-modality matching experiment where observers adjusted the loudness of a tone in response to presented lengths of a metal tape. In one condition, the initial level of the tone to be adjusted was the same as the final adjusted level of the previous trial, whereas in another condition, the tone to be adjusted was reset to a different level before each trial. A fit of the DeCarlo-Cross dynamic model shows that the primary effect of the manipulation was on a judgmental factor, with little or no effect on a perceptual factor. We suggest that starting a trial with the tone at the final adjusted level of the previous trial induced the observer to rely more heavily on the loudness-length pair of the previous trial as a frame of reference for relative judgment; we call this reliance trial-to-trial recalibration. In contrast, when the tone is set to a level independent of its value on the previous trial, there is virtually no effect of one trial on the next trial's performance, a result consistent with the observer maintaining a stable frame of reference. We argue that sequential effects are not unavoidable and that the technique described here adds to a growing list of methods for reducing or eliminating them.

Association↗
PubMed2006

Trial-by-trial estimation of amplitude and latency variability in neuronal spike trains.

The rate function underlying single-trial spike trains can vary from trial to trial. We propose to estimate the amplitude and latency variability in single-trial neuronal spike trains on a trial-by-trial basis. The firing rate over a trial is modeled by a family of rate profiles with trial-invariant waveform and trial-dependent amplitude scaling factors and latency shifts. Using a Bayesian inference framework we derive an iterative fixed-point algorithm from which the single-trial amplitude scaling factors and latency shifts are estimated. We test the performance of the algorithm on simulated data and then apply it to actual neuronal recordings from the sensorimotor cortex of the monkey.

Action Potentials↗
PubMed2000

Consistency behind trial-to-trial variation in intrinsic optical responses to single-whisker movement in the rat D1-barrel cortex.

We examined consistent characteristics behind the trial-to-trial variati on in intrinsic optical imaging of single barrel cortical responses to D 1-whisker movement in 2-5-week postnatal (2-5 W) and adul t (>9-weeks) Wistar rats, and we identified the effective are a of the neural response. The extent/size, configuration and orientation of the intrinsic optical response area varied from trial-to-trial with the same whisker stimulation. We argue that the trial-to-trial variation was due to cortical blood circulation related to the barrel neural activity. Subsequently, interpolating a family of the traces of the optical response area imaged with repeated stimulation for each animal, we extracted a centered circular area from the trial-to-trial response for each animal. Although the trial-to-trial variation decreased gradually with age, the spatial extent of the interpolated response area was consistently about 660 microm in diameter, in agreement with that measured morphologically and/or histochemically. A possible interpretation is that the optically defined area appears to image the actual effective single-barrel response area, as a first approximation. Furthermore, the constancy of the extracted area independent of age suggests that the barrel cortex is, in fact, virtually mature by 2 weeks of age. The extracted area was also nearly independent of the frequency (>/=5 Hz) of whisker movement.

Animals↗
PubMed2004

Bad reporting does not mean bad methods for randomised trials: observational study of randomised controlled trials performed by the Radiation Therapy Oncology Group.

OBJECTIVE: To determine whether poor reporting of methods in randomised controlled trials reflects on poor methods. DESIGN: Observational study. SETTING: Reports of randomised controlled trials conducted by the Radiation Therapy Oncology Group since its establishment in 1968. PARTICIPANTS: The Radiation Therapy Oncology Group. Outcome measures Content of reports compared with the design features described in the protocols for all randomised controlled trials. RESULTS: The methodological quality of 56 randomised controlled trials was better than reported. Adequate allocation concealment was achieved in all trials but reported in only 42% of papers. An intention to treat analysis was done in 83% of trials but reported in only 69% of papers. The sample size calculation was performed in 76% of the studies, but reported in only 16% of papers. End points were clearly defined and alpha and beta errors were prespecified in 76% and 74% of the trials, respectively, but only reported in 10% of the papers. The one exception was the description of drop outs, where the frequency of reporting was similar to that contained in the original statistical files of the Radiation Therapy Oncology Group. CONCLUSIONS: The reporting of methodological aspects of randomised controlled trials does not necessarily reflect the conduct of the trial. Reviewing research protocols and contacting trialists for more information may improve quality assessment.

Clinical Trials, Phase III as Topic↗
PubMedDate not supplied

The impact of the Trial Coordinator in the Diabetes Control and Complications Trial (DCCT). The DCCT Research Group.

The Diabetes Control and Complications Trial (DCCT) is a multicenter, randomized clinical trial studying the effects of two different diabetes regimens on the development and progression of early vascular complications in persons with insulin-dependent diabetes mellitus (IDDM). All of the centers have a Trial Coordinator. We administered a self-report questionnaire to each center to document the different activities for which the Trial Coordinator assumed responsibility in successfully orchestrating the trial. All Trial Coordinators were responsible primarily for recruitment, screening, medical management, education and training, and adherence and administration. Although documentation indicated that the Trial Coordinator was responsible for all of the above activities, the original applications reflected that very few of the Principal Investigators anticipated such a wide variety of duties. A Trial Coordinator was named in only 13 of the 21 applications and of these, only 6 actually assumed the position. This study points out the need to develop a means to define characteristics, background, and training appropriate for candidates for a Trial Coordinator position in future studies.

Allied Health Personnel↗
PubMed2001

Sample size calculations for intervention trials in primary care randomizing by primary care group: an empirical illustration from one proposed intervention trial.

Because of the central role of the general practice in the delivery of British primary care, intervention trials in primary care often use the practice as the unit of randomization. The creation of primary care groups (PCGs) in April 1999 changed the organization of primary care and the commissioning of secondary care services. PCGs will directly affect the organization and delivery of primary, secondary and social care services. The PCG therefore becomes an appropriate target for organizational and educational interventions. Trials testing these interventions should involve randomization by PCG. This paper discusses the sample size required for a trial in primary care assessing the effect of a falls prevention programme among older people. In this trial PCGs will be randomized. The sample size calculations involve estimating intra-PCG correlation in primary outcome: fractured femur rate for those 65 years and over. No data on fractured femur rate were available at PCG level. PCGs are, however, similar in size and often coterminous with local authorities. Therefore, intra-PCG correlation in fractured femur rate was estimated from the intra-local authority correlation calculated from routine data. Three alternative trial designs are considered. In the first design, PCGs are selected for inclusion in the trial from the total population of England (eight regions). In the second design, PCGs are selected from two regions only. The third design is similar to the second except that PCGs are stratified by region and baseline value of fracture rate. Intracluster correlation is estimated for each of these designs using two methods: an approximation which assumes cluster sizes are equal and an alternative method which takes account of the fact that cluster sizes vary. Estimates of sample size required vary between 26 and 7 PCGs in each intervention group, depending on the trial design and the method used to calculate sample size. Not unexpectedly, stratification by baseline value of the outcome variable decreases the sample size required. In our analyses, geographic restriction of the population to be sampled reduces between-cluster variability in the primary outcome. This leads to an increase in precision. When allowance for variable cluster size is made, the increase in precision is not as great as would be expected with equal cluster sizes. This paper highlights the usefulness of routine data in work of this kind, and establishes one of the essential prerequisites for our proposed trial and other trials using primary outcomes with similar between-PCG variation: a feasible sample size.

Accidental Falls↗
PubMed1999

Are randomized control trial outcomes influenced by the inclusion of a placebo group?: a systematic review of nonsteroidal antiinflammatory drug trials for arthritis treatment.

Placebo groups are often included in randomized control trials evaluating drug therapy, yet we know little about the placebo effect. The purpose of our study was to evaluate how the presence of a placebo group in a randomized control trial (RCT) influences the patients' ratings of the efficacy of an active drug therapy and their reporting of its adverse effects. We identified studies published between 1966 and 1994 using MEDLINE. Randomized control trials evaluating acetylsalicylic acid, diclofenac, or indomethacin for the treatment of osteo or rheumatoid arthritis were included in our sample. Two investigators independently extracted data. Fifty-eight treatment arms met our inclusion criteria and were available for analysis. Twenty-five treatment arms evaluated a nonsteroidal antiinflammatory drug (NSAID) in placebo control trials and 33 in comparative trials. Using a logistic regression model to adjust for the differences between the evaluated drugs and between the types of arthritis, we found that patients receiving an NSAID in a placebo control trial were more likely to withdraw due to inefficacy (OR=1.3; 95% CI, 1.0 to 1.6; P=0.04). Using a similar model, withdrawals due to adverse effects were found to be more common when the NSAID was given in trials that did not include a placebo group (OR=1.5; 95% CI, 1.1 to 1.9; P=0.002) as were reports of cutaneous (OR=4.2; 95% CI, 1.7 to 9.9), gastrointestinal (OR=1.6; 95% CI, 1.3 to 2.0), and other types (OR=5.3; 95% CI, 3.8 to 7.4) of adverse effects. Although reports of central nervous system adverse effects were more frequent in the comparative trials, this difference was not significant. Including a placebo group in a RCT changes how patients rate the efficacy and adverse effects of their therapy. Our results highlight the need to consider the placebo effect in the design and analyses of clinical trials.

Aged↗
PubMed1997

Quality of life assessment in clinical trials--guidelines and a checklist for protocol writers: the U.K. Medical Research Council experience. MRC Cancer Trials Office.

Many clinical trials groups now routinely consider including Quality of Life (QoL) assessment in trials. Indeed, several have policies stating that QoL should be considered as a potential endpoint in all new trials and that if it is not to be evaluated the applicants should justify not doing so. However, inclusion of QoL in clinical trials presents a number of difficult organisational issues, and serious problems in compliance have frequently been reported. Thus, in multicentre clinical trials many of the expected QoL questionnaires fail to be successfully completed and returned, although a few groups have claimed high success rates. However, it is well recognised that if questionnaires are missing, there may be bias in the interpretation of trial results, and the estimates of treatment differences and the overall level of QoL may be inaccurate and misleading. Hence it is important to seek methods of improving compliance, at the level of both the participating institution and the patient. We describe a number of methods for addressing these issues, which we suggest should be considered by all those writing clinical trial protocols involving QoL assessment. These are based upon over a decade of experience with assessing QoL in Medical Research Council (MRC) cancer clinical trials. In particular, we provide a checklist for points that should be covered in protocols. Examples are given from a range of current MRC Cancer Trials Office protocols, which it is proposed might act as templates when writing new protocols.

Clinical Protocols↗
PubMed2004

Commentary: the 1944 patulin trial: the first properly controlled multicentre trial conducted under the aegis of the British Medical Research Council.

The 1948 report of the British Medical Research Council's randomized trial of streptomycin for pulmonary tuberculosis is widely regarded as marking the beginning of the modern history of controlled clinical trials. Four years earlier, however, a methodologically sophisticated multicentre trial conducted under the aegis of the Medical Research Council was reported, which assessed the effects of the antibiotic patulin on the course of common colds. Philip D'Arcy Hart and Joan Faulkner (later Joan Doll) were the secretary and assistant secretary, respectively, to the committee overseeing the trial, and they clearly recognized the importance of preventing foreknowledge of allocations from those admitting patients to the study. To do this and to 'muddle people up', they and Ruth D'Arcy Hart devised a scheme involving the use of two patulin groups and two placebo groups, allocating patients to one of these four groups using strict rotation. Philip D'Arcy Hart believes that this study has been overshadowed by the celebrated streptomycin trial (for which he was also secretary to the oversight committee) because no beneficial effect of patulin was detected, and because the report of the streptomycin trial referred to the use of random sampling numbers to generate the allocation schedule. This article makes clear why we agree with Philip D'Arcy Hart that the 1944 patulin trial deserves wider recognition as the first well controlled, multicentre clinical trial to have been conducted under the aegis of the British Medical Research Council. This status is reflected in the International Journal of Epidemiology's reproduction of the full text of the trial report in this issue of the journal.

Common Cold↗