The potential for bias in reporting of industry-sponsored clinical trials

Concerns about potentially misleading reporting of pharmaceutical industry research have surfaced many times. The potential for duality (and thereby conflict) of interest is only too clear when you consider the sums of money required for the discovery, development and commercialization of new medicines. As the ability of major, mid-size and small pharmaceutical companies to innovate has waned, as evidenced by the seemingly relentless decline in the numbers of new medicines approved by Food and Drug Administration and European Medicines Agency year-on-year, not only has the cost per new approved medicine risen: so too has the public and media concern about the extent to which the pharmaceutical industry is open and honest about the efficacy, safety and quality of the drugs we manufacture and sell. In 2005 an Editorial in Journal of the American Medical Association made clear that, so great was their concern about misleading reporting of industry-sponsored studies, henceforth no article would be published that was not also guaranteed by independent statistical analysis. We examine the precursors to this Editorial, as well as its immediate and lasting effects for statisticians, for the manner in which statistical analysis is carried out, and for the industry more generally.

A practical comparison of blinded methods for sample size reviews in survival data clinical trials.

This paper presents practical approaches to the problem of sample size re-estimation in the case of clinical trials with survival data when proportional hazards can be assumed. When data are readily available at the time of the review, on a full range of survival experiences across the recruited patients, it is shown that, as expected, performing a blinded re-estimation procedure is straightforward and can help to maintain the trial's pre-specified error rates. Two alternative methods for dealing with the situation where limited survival experiences are available at the time of the sample size review are then presented and compared. In this instance, extrapolation is required in order to undertake the sample size re-estimation. Worked examples, together with results from a simulation study are described. It is concluded that, as in the standard case, use of either extrapolation approach successfully protects the trial error rates. Copyright © 2012 John Wiley & Sons, Ltd.

Conditionally unbiased estimation in phase II/III clinical trials with early stopping for futility

Seamless phase II/III clinical trials combine traditional phases II and III into a single trial that is conducted in two stages, with stage 1 used to answer phase II objectives such as treatment selection and stage 2 used for the confirmatory analysis, which is a phase III objective. Although seamless phase II/III clinical trials are efficient because the confirmatory analysis includes phase II data from stage 1, inference can pose statistical challenges. In this paper, we consider point estimation following seamless phase II/III clinical trials in which stage 1 is used to select the most effective experimental treatment and to decide if, compared with a control, the trial should stop at stage 1 for futility. If the trial is not stopped, then the phase III confirmatory part of the trial involves evaluation of the selected most effective experimental treatment and the control. We have developed two new estimators for the treatment difference between these two treatments with the aim of reducing bias conditional on the treatment selection made and on the fact that the trial continues to stage 2. We have demonstrated the properties of these estimators using simulations

A comparison of methods for constructing confidence intervals after phase II/III clinical trials

Recently, in order to accelerate drug development, trials that use adaptive seamless designs such as phase II/III clinical trials have been proposed. Phase II/III clinical trials combine traditional phases II and III into a single trial that is conducted in two stages. Using stage 1 data, an interim analysis is performed to answer phase II objectives and after collection of stage 2 data, a final confirmatory analysis is performed to answer phase III objectives. In this paper we consider phase II/III clinical trials in which, at stage 1, several experimental treatments are compared to a control and the apparently most effective experimental treatment is selected to continue to stage 2. Although these trials are attractive because the confirmatory analysis includes phase II data from stage 1, the inference methods used for trials that compare a single experimental treatment to a control and do not have an interim analysis are no longer appropriate. Several methods for analysing phase II/III clinical trials have been developed. These methods are recent and so there is little literature on extensive comparisons of their characteristics. In this paper we review and compare the various methods available for constructing confidence intervals after phase II/III clinical trials.

A comparison of methods for treatment selection in seamless phase II/III clinical trials incorporating information on short-term endpoints

In an adaptive seamless phase II/III clinical trial interim analysis, data are used for treatment selection, enabling resources to be focused on comparison of more effective treatment(s) with a control. In this paper, we compare two methods recently proposed to enable use of short-term endpoint data for decision-making at the interim analysis. The comparison focuses on the power and the probability of correctly identifying the most promising treatment. We show that the choice of method depends on how well short-term data predict the best treatment, which may be measured by the correlation between treatment effects on short- and long-term endpoints.

Casein-derived lactotripeptides reduce systolic and diastolic blood pressure in a meta-analysis of randomised clinical trials

There is an urgent need to treat individuals with high blood pressure (BP) with effective dietary strategies. Previous studies suggest a small, but significant decrease in BP after lactotripeptides (LTP) ingestion, although the data are inconsistent. The study aim was to perform a comprehensive meta-analysis of data from all relevant randomised controlled trials (RCT). Medline, Cochrane library, EMBASE and Web of Science were searched until May 2014. Eligibility criteria were RCT that examined the effects of LTP on BP in adults, with systolic BP (SBP) and diastolic BP (DBP) as outcome measures. Thirty RCT met the inclusion criteria, which resulted in 33 sets of data. The pooled treatment effect for SBP was −2.95 mmHg (95% CI: −4.17, −1.73; p < 0.001), and for DBP was −1.51 mmHg (95% CI: −2.21, −0.80; p < 0.001). Sub-group analyses revealed that reduction of BP in Japanese studies was significantly greater, compared with European studies (p = 0.002 for SBP and p < 0.001 for DBP). The 24-h ambulatory BP (AMBP) response to LTP supplementation was statistically non-significant (p = 0.101 for SBP and p = 0.166 for DBP). Both publication bias and “small-study effect” were identified, which shifted the treatment effect towards less significant SBP and non-significant DBP reduction after LTP consumption. LTP may be effective in BP reduction, especially in Japanese individuals; however sub-group, meta-regression analyses and statistically significant publication biases suggest inconsistencies.

An Agent-Based Approach to Real-Time Patient Identification for Clinical Trials

Patient recruitment for clinical trials is expensive and has been a significant challenge, with many trials not achieving their recruitment goals. One method that shows promise for improving recruitment is the use of interactive prompts that inform practitioners of patient eligibility for clinical trials during consultation. This paper presents the ePCRN-IDEA recruitment system, which utilises an agent-based infrastructure to enable real-time recruitment of patients. In essence, whenever patients enter a clinic, the system compares their details against eligibility criteria, which define the requirements of active clinical trials. If a patient is found to be eligible, a prompt is raised to notify the user. In this way, it becomes possible for recruitment to take place quickly in a cost effective manner, whilst maintaining patient trust through the involvement of their own health care practitioner.

Clinical trials in Asia Pacific

The article provides information on biotechnology in Asia. According to research, Asian Pacific biotechnology is known for its competent staff, world class technologies, efficient utilities, and abundance of reasonably priced raw materials. Other attributes of the Asia Pacific region that makes it a sought-after location in conducting clinical studies are also discussed. Meanwhile, the role of Contract Research Organization (CRO) in clinical studies in the Asia Pacific region is also presented.

Quality of reporting of randomized clinical trials in abstracts of the 2005 annual meeting of the American College of Rheumatology.

Objective: To determine the quality of abstracts reporting randomized clinical trials (RCT) at the 2005 Annual Scientific Meeting of the American College of Rheumatology.

Methods: All 2005 abstracts including late-breaking abstracts were assessed. An abstract was deemed to be reporting an RCT if it indicated that participants were randomized in the title or body of the abstract. RCT were excluded if they included only pharmacokinetic data. The CONSORT checklist was applied and relevant data extracted. We defined manufacturer support as acknowledgment of industry support or industry employee as co-author.

Results: Of 2146 abstracts, 143 (6.7%) reported RCT. Of these, 78.3% were drug trials, and 63.6% indicated manufacturer support. Only 30.8% of abstracts used "randomized" in the title, 44.1% did not explicitly state whether blinding was undertaken, and only 7.0% clearly stated who was blinded. Thirty percent of studies did not give an explicit definition of eligibility criteria of participants. While 84.6% explicitly described the experimental intervention, only 37.1% explicitly described the comparator intervention. Only 21% explicitly stated that an intention to treat analysis was performed. Baseline demographic and clinical characteristics were reported in 48.3%. While most abstracts reported summary results for each treatment group, only 35.7% reported effect size with its precision.

Conclusion: The quality of reporting is suboptimal in many RCT abstracts. Abstracts reporting RCT would benefit from a structured approach that ensures more detailed reporting of eligibility criteria, active and comparator interventions, flow of participants, and adequate summary and precision of results.

Do we need to flick the switch? The need for a broader conceptualization of iatrogenic course aggravation in clinical trials of bipolar disorder?

The term ‘switching’ is often used in bipolar disorder when describing polarity changes in bipolar disorder, but this term is ambiguous and imprecise, and is sometimes used interchangeably with the term ‘cycling’. Furthermore, polarity changes in bipolar disorder can be understood in different ways, because their clinical manifestations range from the emergence of subthreshold symptoms to a full episode of the opposite pole. Besides the need to tighten the meaning of the term ‘switching’, this paper also argues that switching does not adequately describe the complex phenomena that occur with course aggravation of bipolar disorder, such as alteration in episode frequency or amplitude. A more-fine grained approach to course aggravation in bipolar disorder is proposed, which incorporates trans-polar switching, index polarity aggravation, as well as alterations in episodic amplitude, episodic duration, and interepisode length. This approach has the potential to capture a broader, more fine-grained and clinically relevant picture of the process of aggravation of the bipolar cycle.

Quality of life in restless legs syndrome: A systematic review of clinical trials and a critical review of instruments

Restless legs syndrome (RLS) is a neurological movement disorder characterized by sensory symptoms and motor disturbances. While the underlying cause remains unknown, it is suggested that 20–25% of people with RLS are affected seriously enough to require pharmacological treatment. Dopamine agonists (DAs) are the most common treatment and act by increasing the low levels of dopamine to which RLS is often attributed. A growing literature highlights the debilitating and distressing nature of this condition from the patient's perspective. While sleep problems are most commonly reported, the impact of RLS on quality of life (QOL) is wide ranging, affecting relationships with partners, sex life, family life, social life, leisure activities, friendships, everyday activities, concentration, travel, career/work, sleep, and health.

We conducted a systematic review of clinical trials in which DAs have been evaluated in terms of RLS-specific QOL, i.e. their impact on the QOL of people with RLS, and critically reviewed the development history and measurement properties of RLS-specific QOL instruments.

A systematic search using terms synonymous with RLS, DAs and QOL was conducted using Scopus software, which includes MEDLINE, PsycINFO, EMBASE, and CINAHL. Our search covered publications from 2000 (prior to which RLS-specific QOL measures did not exist) to August 2009. Trials were included in our review if they evaluated DAs for the treatment of adults with RLS and reported evaluation using an RLS-specific QOL measure. We also ran citation searches to identify papers reporting the development history and measurement properties of the identified RLS-specific QOL instruments.

Three measures of RLS-specific QOL have been developed in recent years and are reviewed here: the Restless Legs Syndrome Quality of Life (RLSQOL) questionnaire, the Restless Legs Syndrome Quality of Life Instrument (RLS-QLI), and the Quality of Life Restless Legs Syndrome (QOL-RLS) measure. Critical review indicates that each has limitations (particularly in terms of published developmental history and content validity). Eleven trials of DAs were identified that included assessment of RLS-specific QOL (nine using the RLSQOL and two using the QOL-RLS). In all studies, significant improvements in RLS-specific QOL were observed, although these were mostly short term (12 weeks) and large placebo effects were also noted.

In people with RLS, the use of DAs has been shown to improve RLS-specific QOL. Longer-term, large-scale studies may be needed to confirm these findings and demonstrate statistically significant improvements in RLS-specific QOL at lower doses. Further development of the RLS-specific QOL measures is needed to ensure that the full impact of RLS (and the full benefit of new treatments) on aspects of life identified as important to individuals is captured in future studies.