The continuing unethical use of placebo controls

Systematic evaluation of non-inferiority and equivalence randomized trials of anti-infective drugs

The non-inferiority (NI) and equivalence (EQ) design is used widely in the clinical trials of anti-infective drugs, but still many arguments for, and against, conducting active control NI/EQ trials rather than simple placebo controlled trials. We searched Pubmed database and conducted a systematic literature review (1992-2011) to assess the methodological aspects of NI and EQ randomized trials of anti-infective drugs. A total of 335 publications with 337 trials were included. Of them, 235 trials reported a pre-specified margin of 10-15%. A proportion (e.g., cure, successful, failure) was used as the primary outcome in 316 trials (93.8%). Test treatments were non-inferior or equivalent to the control treatment in 325 trials (93.4%). The historical evidence for the effect of the control drug was specified in 38 trials (11.3%). For the literature of NI/EQ trials in anti-infective treatment, aspects that need improvement include the description of study participation, trial implementation, historical evidence and endpoint for the efficacy of control, inclusion of flow diagrams and figures that present margins and confidence intervals according to CONSORT criteria.

Suicide-related events in young people following prescription of SSRIs and other antidepressants: a self-controlled case series analysis

OBJECTIVES

We aimed to examine the temporal association between selective serotonin reuptake inhibitors (SSRI) and tricyclic antidepressant (TCA) prescriptions and suicide-related events in children and adolescents.

DESIGN

Self-controlled case series.

SETTING

Electronic health records were used from 479 general practices in The Health Improvement Network (THIN) UK primary care database from 1995 to 2009.

PARTICIPANTS

81 young people aged 10-18 years with a record of completed suicide, 1496 who attempted suicide, 1178 with suicidal ideation and 2361 with intentional self-harm.

MAIN OUTCOME MEASURES

Incidence Rate Ratios (IRRs) for completed and attempted suicide, suicidal ideation and intentional self-harm.

RESULTS

For non-fatal suicide-related behaviour, IRRs were similar for the time the person was prescribed either SSRIs or TCAs: IRRs increased during pre-exposure, peaked on prescription day, were stable up to the fourth prescription-week, and decreased after the prescriptions were stopped. For both types of antidepressants, IRRs were lower or similar to pre-exposure levels during the period of prescription. For SSRIs, there was an increase in the IRR for completed suicide on the day of prescription (N=5; IRR=42.5, 95% CI 4.5 to 403.4), and during the fourth week of SSRI prescription (N=2; IRR=11.3, 95% CI 1.1 to 115.6).

CONCLUSIONS

We found that a very small number of young people were prescribed antidepressants and that there was an absence of a sustained increase in rates of suicide-related events in this group. There were no systematic differences between the association of TCAs and SSRIs and the incidence risk ratios for attempted suicide, suicidal ideation or intentional self-harm and, apart from the day of prescription, rates did not exceed pre-exposure levels. The pattern of IRR for suicide for SSRIs was similar to that found in non-fatal suicide-related events. Our results warrant a re-evaluation of the current prescription of SSRIs in young people. We recommend the creation of a pragmatic registry for active pharmacovigilance.

Systematic review of available evidence on 11 high-priced inpatient orphan drugs

Background

Attention for Evidence Based Medicine (EBM) is growing, but evidence for orphan drugs is argued to be limited and inferior. This study systematically reviews the available evidence on clinical effectiveness, cost-effectiveness and budget impact for orphan drugs.

Methods

A systematic review was performed in PubMed, Embase, NHS EED and HTA databases for 11 inpatient orphan drugs listed on the Dutch policy rule on orphan drugs. For included studies, we determined the type of study and various study characteristics.

Results

A total of 338 studies met all inclusion criteria. Almost all studies (96%) focused on clinical effectiveness of the drug. Of these studies, most studies were case studies (41%) or observational studies (39%). However, for all orphan diseases at least one experimental or quasi-experimental study was found, and a randomized clinical trial was available for 60% of the orphan drugs. Eight studies described the cost-effectiveness of an orphan drug; an equal number described an orphan drug’s budget impact.

Conclusions

Despite the often heard claim that RCTs are not feasible for orphan drugs, we found that an RCT was available in 60% of orphan drugs investigated. Cost-effectiveness and budget impact analyses for orphan drugs are seldom published.

Bayesian approach to the design and analysis of non-inferiority trials for anti-infective products

In the absence of placebo-controlled trials, determining the non-inferiority (NI) margin for comparing an experimental treatment with an active comparator is based on carefully selected well-controlled historical clinical trials. With this approach, information on the effect of the active comparator from other sources including observational studies and early phase trials is usually ignored because of the need to maintain active comparator effect across trials. This may lead to conservative estimates of the margin that translate into larger sample-size requirements for the design and subsequent frequentist analysis, longer trial durations, and higher drug development costs. In this article, we provide methodological approaches to determine NI margins that can utilize all relevant historical data through a novel power adjusted Bayesian meta-analysis, with Dirichlet process priors, that puts ordered weights on the amount of information a set of data contributes. We also provide a Bayesian decision rule for the non-inferiority analysis that is based on a broader use of available prior information and a sample-size determination that is based on this Bayesian decision rule. Finally, the methodology is illustrated through several examples.

Diagnosis and management of Alzheimer's disease: past, present and future ethical issues

There is great interest in the ethical issues associated with Alzheimer's disease (AD) and related dementias given the prevalence of AD and the evolving neuroscience landscape in matters of diagnoses and therapeutics. Much of the ethics discussion arises in the tension between the principle of not doing harm (principle of non-maleficence) in this vulnerable population and the development of effective treatments (principle of beneficence). Autonomy and capacity issues are also numerous, wide-ranging, and concern (1) day to day affairs such as driving safely and spending money wisely, (2) life-time events such as designating a legal representative in case of incapacity, making a will, (3) consenting to treatment and diagnostic procedures, (4) participating in research. The latter issue is particularly thorny and illustrates well the complexity of tackling concerns related to capacity. The impetus to protect AD patients has partly led to ethics regulation and policies making research on inapt patients more difficult because of stringent requirements for signed informed consent or for showing the value of the research to this specific patient population. New issues are arising that relate to earlier diagnosis using biomarkers and (possibly soon) the use of drugs that modify disease progression. We here summarize and discuss the different ethical issues associated with AD from a historical perspective, with emphasis on diagnostic and treatments issues.

Creation and implementation of a historical controls database from randomized clinical trials

BACKGROUND

Ethical concerns about randomly assigning patients to suboptimal or placebo arms and the paucity of willing participants for randomization into control and experimental groups have renewed focus on the use of historical controls in clinical trials. Although databases of historical controls have been advocated, no published reports have described the technical and informatics issues involved in their creation.

OBJECTIVE

To create a historical controls database by leveraging internal clinical trial data at Pfizer, focusing on patients who received only placebo in randomized controlled trials.

METHODS

We transformed disparate clinical data sources by indexing, developing, and integrating clinical data within internal databases and archives. We focused primarily on trials mapped into a consistent standard and trials in the pain therapeutic area as a pilot.

RESULTS

Of the more than 20,000 internal Pfizer clinical trials, 2404 completed placebo controlled studies with a parallel design were identified. Due to challenges with informed consent and data standards used in older clinical trials, studies completed before 2000 were excluded, yielding 1134 studies from which placebo subjects and associated clinical data were extracted.

CONCLUSIONS

It is technically feasible to pool portions of placebo populations through a stratification and segmentation approach for a historical placebo group database. A sufficiently large placebo controls database would enable previous distribution calculations on representative populations to supplement, not eliminate, the placebo arm of future clinical trials. Creation of an industry-wide placebo controls database, utilizing a universal standard, beyond the borders of Pfizer would add significant efficiencies to the clinical trial and drug development process.

Compellingness: assessing the practical relevance of clinical research results

While the critical appraisal of clinical research has generally focused on aspects of study design and statistical analysis, other features of clinical studies appear to be more important to clinicians for assessing the value of a particular study in the care of particular patients. These features relate to the quality of the knowledge derived from the research, the value of the results to the care of individual patients, and the responsibility of clinicians to be stewards of limited resources. Twelve features of clinical research studies that affect how compelling individual clinicians find the results are proposed and examined here. By better understanding what makes clinical research compelling enough to alter or reinforce clinical practice, clinical researchers can design future studies to better serve the needs of clinicians and patients.

Mesalazine granules 1.5 g once-daily maintain remission in patients with ulcerative colitis who switch from other 5-ASA formulations: a pooled analysis from two randomised controlled trials

BACKGROUND

Mesalazine (mesalamine) granules (MG) were shown to be effective for the maintenance of remission of ulcerative colitis (UC) in two double-blind placebo-controlled trials.

AIM

To evaluate the efficacy of once-daily MG for maintenance of remission in patients with UC who switched from other 5-aminosalicylic acid (5-ASA) formulations.

METHODS

Data from two independent multicenter, randomised, double-blind, placebo-controlled, 6-month trials evaluating patients with UC in remission were combined for analysis of a subpopulation of patients who switched from other 5-ASA formulations to MG 1.5 g or placebo upon randomisation. The primary endpoint was the percentage of patients who remained relapse-free at Month 6 or end of treatment. Relapse was defined as a Sutherland Disease Activity Index (SDAI) rectal bleeding score ≥1 and mucosal appearance score ≥2, a UC flare or medication used to treat a UC flare.

RESULTS

Of the 487 patients who received 5-ASA maintenance therapy at enrolment, 322 were in the MG group and 165 were in the placebo group. The percentage of patients who remained relapse-free (based on Sutherland Disease Activity Index scores) after 6 months was significantly higher with MG than placebo (78.3% vs. 58.8%, P < 0.001). Rectal bleeding, stool frequency and the physician's rating of disease activity remained unchanged after 6 months in a higher percentage of patients using MG compared with those on placebo (P < 0.004 for each endpoint).

CONCLUSION

Mesalazine granules 1.5 g once-daily is effective for maintenance of remission in UC patients who switch from other 5-ASA formulations. ClinicalTrials.gov identifiers NCT00744016, NCT00767728.

Bayesian approach to non-inferiority trials for normal means

Regulatory framework recommends that novel statistical methodology for analyzing trial results parallels the frequentist strategy, e.g. the new method must protect type-I error and arrive at a similar conclusion. Keeping these in mind, we construct a Bayesian approach for non-inferiority trials with normal response. A non-informative prior is assumed for the mean response of the experimental treatment and Jeffrey's prior for its corresponding variance when it is unknown. The posteriors of the mean response and variance of the treatment in historical trials are then assumed as priors for its corresponding parameters in the current trial, where that treatment serves as the active control. From these priors, a Bayesian decision criterion is derived to determine whether the experimental treatment is non-inferior to the active control. This criterion is evaluated and compared with the frequentist method using simulation studies. Results show that both Bayesian and frequentist approaches perform alike, but the Bayesian approach has a higher power when the variances are unknown. Both methods also arrive at the same conclusion of non-inferiority when applied on two real datasets. A major advantage of the proposed Bayesian approach lies in its ability to provide posterior probabilities for varying effect sizes of the experimental treatment over the active control.

Pediatric oncology research in low income countries: ethical concepts and challenges

Uneven strides in research and care have led to discrepancies in childhood cancer outcomes between high and low income countries (LICs). Collaborative research may help improve outcomes in LICs by generating knowledge for local scientific communities, augmenting knowledge translation, and fostering context-specific evaluation of treatment protocols. However, the risks of such research have received little attention. This paper investigates the relationship between pediatric oncology research in LICs and four core issues in the ethics literature: standard of care, trial benefits, ethics review, and informed consent. Our aims are to highlight the importance of this field and the need for further inquiry.

Ethical issues of placebo-controlled studies in depression and a randomized withdrawal trial in Japan: case study in the ethics of mental health research

The use of placebo controls in psychiatric research is controversial. In this article, we focus on a troubling Japanese case of a randomized withdrawal trial of the antidepressant sertraline and analyze the ethical issues underlying it. First, we consider whether a placebo-controlled withdrawal trial should, in general, be considered more ethical than a standard placebo-controlled trial. We argue that the use of a placebo arm in this trial is ethically permissible but that there is no good reason to use a withdrawal trial design. Second, we discuss whether our moral evaluation of the use of placebo in this case should change when the special Japanese regulatory environment is taken into account. We argue that it should not and conclude that the use of withdrawal design in this case is ethically unacceptable.

Is randomization to placebo safe? Risk in placebo-controlled angina trials: angina risk meta-analysis

OBJECTIVE

It was the aim of this study to document the risks of symptomatic patients with angina in placebo-controlled, anti-anginal drug development trials in which symptom-limited exercise testing was used as the primary endpoint.

PATIENTS AND METHODS

The original case report forms submitted to the United States Food and Drug Administration in support of approval of new or supplemental new drug applications between 1973 and 2001 were identified and subjected to a by-patient meta-analysis, utilizing both a maximum likelihood analysis and classical Mantel-Haenszel methods.

RESULTS

There were 63 placebo-controlled, clinical trials that randomized 10,865 patients, with 1,047 patient-years of observation time. The trials involved 21 different chemical entities from 4 different drug classes. The relative risk (RR) for withdrawal (placebo compared to drug-treated patients) was not increased [RR = 0.92, 95% confidence interval (CI) 0.78-1.08; p = 0.28]. Of interest, a RR of 0.54 (95% CI 0.26-1.04; p < 0.068) for irreversible harm (a combination of cerebrovascular accidents, myocardial infarction and death) and a RR of 0.89 (95% CI 0.61-1.30; p = 0.56) for serious cardiovascular events (myocardial infarction, congestive heart failure, cerebrovascular accidents) both non-statistically significantly favored being randomized to placebo.

CONCLUSIONS

For the development of current or future drugs for the treatment of angina, there is no obvious contraindication to the use of placebo controls and exercise tolerance testing.

Programmes for parents with a mental illness

Parents with a mental illness experience the same parenting stressors that other parents do, and at the same time need to manage their mental illness. However, few programmes are designed for parents who have a mental illness, with older children (as opposed to interventions for mothers with infants). This study identified the common components across six programmes developed for parents with a mental illness who have older children. Australian clinicians, responsible for six parenting programmes for those with a mental illness, participated in individual, semi-structured interviews, during 2008. Programme manuals and evaluation reports were also sourced. Analyses involved thematic analysis, inter-rater reliability and respondent validation. Data were organized in three main areas: (1) programme description (format, goals, length and participants' inclusion criteria); (2) theoretical framework (including clinicians' beliefs and evidence underpinning programmes); and (3) evaluation designs and methodologies. It was found that clinicians facilitated education and support via a peer intervention model for parents with various mental illness diagnoses, responsive to the needs of parents and in a time flexible manner. At the same time, clinicians found it difficult to articulate the theoretical framework of their programmes and employed mostly simplistic evaluation strategies.

Drug efficacy by direct and adjusted indirect comparison to placebo: An illustration by Mycobacterium avium complex prophylaxis in HIV

Background

Our goal was to illustrate a method for making indirect treatment comparisons in the absence of head-to-head trials, by portraying the derivation of published efficacies for prophylaxis regimens of HIV-related opportunistic infections.

Results

We identified published results of randomized controlled trials from the United States in which HIV-infected patients received rifabutin, azithromycin, clarithromycin, or placebo for prophylaxis against Mycobacterium avium complex (MAC). We extracted the number of subjects, follow-up time, primary MAC events, mean CD4 count, and proportion of subjects on mono or dual antiretroviral therapy (ART) from each study. We derived the efficacy of each drug using adjusted indirect comparisons and, when possible, by direct comparisons. Five articles satisfied our inclusion criteria. Using direct comparison, we estimated the efficacies of rifabutin, clarithromycin, and azithromycin compared to placebo to be 53% (95% CI, 48-61%), 66% (95% CI, 61-74%), and 66% (95% CI, 60-81%), respectively. Using adjusted indirect calculations, the efficacy of rifabutin compared to placebo ranged from 41% to 44%. The adjusted indirect efficacies of clarithromycin and azithromycin were estimated to be 73% and 72%, respectively.

Conclusions

Accurate estimates of specific drug dosages as compared to placebo are important for policy and implementation research. This study illustrates a simple method of adjusting for differences in study populations by using indirect comparisons in the absence of head-to-head HIV clinical trials.

Placebo response in clinical trials with schizophrenia patients

PURPOSE OF REVIEW

The magnitude of placebo response is an important factor in the outcome of clinical trials, in that excessive placebo response can obscure true drug-placebo differences. There is ample evidence of the impact of elevated placebo response in trials of major depression, but less intensive research has been done in the area of schizophrenia. We present a current review of placebo response in clinical trials of schizophrenia.

RECENT FINDINGS

The existing evidence suggests that placebo response in schizophrenia trials may be similar in magnitude, quality, and impact to that observed in depression trials, and has similarly increased over the past several years. We discuss factors influencing excessive placebo response during the conduct of clinical trials and how they may be managed to help minimize placebo response.

SUMMARY

There does not appear to be any single major factor contributing to the high levels of placebo response in schizophrenia clinical trials; therefore, a multipronged approach to minimizing excessive placebo response or its impact is recommended.

Use of invasive placebos in research on local anaesthetic interventions

Placebos play a vital role in clinical research, but their invasive use in the context of local anaesthetic blocks is controversial. We assessed whether recently published randomised controlled trials of local anaesthetic blocks risked harming control group patients in contravention of the Declaration of Helsinki. We developed the 'SHAM' (Serious Harm and Morbidity) scale to assess risk: grade 0 = no risk (no intervention); grade 1 = minimal risk (for example, skin allergy to dressing); grade 2 = minor risk (for example, subcutaneous haematoma, infection); grade 3 = moderate risk (with or without placebo injection) (for example, neuropraxia); and grade 4 = major risk (such as blindness, pneumothorax, or liver laceration). Placebo interventions of the 59 included trials were given a SHAM grade. Nine hundred and nineteen patients in 31 studies, including six studies with 183 children, received an invasive placebo assessed as SHAM grade ≥ 3. A high level of agreement (78%, κ = 0.80, p < 0.001) for SHAM grades 0-4 increased to 100% following discussion between assessors. More than half of the randomised controlled study designs subjected patients in control groups to risks of serious or irreversible harm. A debate on whether it is justifiable to expose control group patients to risks of serious harm is overdue.

The placebo mystique: Implications for clinical trial methodology

AIM

The World Medical Association Declaration of Helsinki states that the use of a placebo in a clinical trial can only be justified ethically when no proven active treatment is available as a comparison. Despite this, placebos remain a popular choice as controls in clinical trials. Recent literature reviews have suggested that reliance on placebos may, in part, be because of methodological misconceptions about the need for placebos to control for the 'placebo effect'. This study aimed to assess doctors' understanding of the requirements for placebo use in clinical trials.

METHODS

Two hundred doctors working in tertiary hospitals in Melbourne, Australia were surveyed in regards to their understanding of the role of the placebo and placebo effects in clinical trials. There was a 72% response rate. Doctors were specifically asked if a placebo was required in a randomised clinical trial, in preference to another form of control, to control for the 'placebo effect'.

RESULTS

The majority of respondents (62%) incorrectly believed that placebos are essential to control for the 'placebo effect' in a randomised clinical trial.

CONCLUSIONS

Misconceptions about the methodological requirement for placebos in randomised controlled trials may influence researcher decisions to use placebo controls in unethical situations.

Long-term (5 year) safety of bronchial thermoplasty: Asthma Intervention Research (AIR) trial

BACKGROUND

Bronchial thermoplasty (BT) is a bronchoscopic procedure that improves asthma control by reducing excess airway smooth muscle. Treated patients have been followed out to 5 years to evaluate long-term safety of this procedure.

METHODS

Patients enrolled in the Asthma Intervention Research Trial were on inhaled corticosteroids ≥200 μg beclomethasone or equivalent + long-acting-beta2-agonists and demonstrated worsening of asthma on long-acting-β2-agonist withdrawal. Following initial evaluation at 1 year, subjects were invited to participate in a 4 year safety study. Adverse events (AEs) and spirometry data were used to assess long-term safety out to 5 years post-BT.

RESULTS

45 of 52 treated and 24 of 49 control group subjects participated in long-term follow-up of 5 years and 3 years respectively. The rate of respiratory adverse events (AEs/subject) was stable in years 2 to 5 following BT (1.2, 1.3, 1.2, and 1.1, respectively,). There was no increase in hospitalizations or emergency room visits for respiratory symptoms in Years 2, 3, 4, and 5 compared to Year 1. The FVC and FEV1 values showed no deterioration over the 5 year period in the BT group. Similar results were obtained for the Control group.

CONCLUSIONS

The absence of clinical complications (based on AE reporting) and the maintenance of stable lung function (no deterioration of FVC and FEV1) over a 5-year period post-BT in this group of patients with moderate to severe asthma support the long-term safety of the procedure out to 5 years.

Research ethics I: Responsible conduct of research (RCR)--historical and contemporary issues pertaining to human and animal experimentation

PURPOSE

In this series of articles--Research Ethics I, Research Ethics II, and Research Ethics III--the authors provide a comprehensive review of the 9 core domains for the responsible conduct of research (RCR) as articulated by the Office of Research Integrity. In Research Ethics I, they present a historical overview of the evolution of RCR in the United States then examine the evolution of human and animal experimentation from the birth of scientific medicine through World War II to the present day.

METHOD

They relied on authoritative documents, both historical and contemporary, insightful commentary, and empirical research in order to identify current issues and controversies of potential interest to both faculty and students.

CONCLUSIONS

The authors have written this article from a historical perspective because they think all readers interested in RCR should appreciate how the history of science and all the good--and harm--it has produced can inform how researchers practice responsible research in the 21st century and beyond.

Research ethics II: Mentoring, collaboration, peer review, and data management and ownership

PURPOSE

In this series of articles--Research Ethics I, Research Ethics II, and Research Ethics III--the authors provide a comprehensive review of the 9 core domains for the responsible conduct of research (RCR) as articulated by the Office of Research Integrity. In Research Ethics II, the authors review the RCR domains of mentoring, collaboration, peer review, and data management and ownership.

METHOD

They relied on authoritative documents, both historical and contemporary, insightful commentary, and empirical research in order to identify current issues and controversies of potential interest to both faculty and students.

CONCLUSIONS

The authors close by urging readers to stay abreast of the manifold ethics issues facing today's community of scientists, policymakers, and research institutions, and to adhere to best practices as they evolve.

Ensayo clinico para la enfermeria basada en evidencia: un desafio alcanzable

El ensayo clínico aleatorio constituye el diseño de investigación más riguroso para estudios de intervenciones. En este tipo de estudios, el investigador está interesado en determinar si existe una relación causa-efecto entre un tratamiento y el resultado. Para ello debe comparar grupos de individuos que han sido asignados a recibir diferente nivel de exposición a la intervención, y así determinar si existe el efecto. Hoy en día, se reconoce como uno de los mejores estándares de evidencia para aplicar en la Enfermería Basada en Evidencia. En este contexto, este artículo plantea las principales características de los ensayos clínicos aleatorios, su aplicación, las consideraciones requeridas en su implementación así como sus limitaciones. Con esto se espera estimular su uso para las intervenciones de enfermería en que pueda ser aplicado, hecho relevante ya que desde una perspectiva empírica aportan las mejores pruebas para la Enfermería Basada en Evidencias.

Evaluating equivalence and noninferiority trials

PURPOSE

The conceptual issues related to the design of equivalence and non-inferiority trials and considerations for interpreting the findings of such trials are described.

SUMMARY

Comparative effectiveness research (CER) has recently gained importance in the evaluation of different treatment alternatives. Large, prospective, randomized controlled trials (RCTs) conducted with patient populations under routine practice conditions can yield high-quality CER results. A Phase III RCT, usually conducted for establishing superiority of one treatment over another, is called a superiority trial, and the statistical test associated with it is known as a superiority test. In a pragmatic equivalence trial, a researcher aims to test if two treatments are identical (within a specified range) with respect to some predefined clinical criteria. Pragmatic noninferiority trials aim to show if a test therapy is no worse than a standard therapy with respect to achieving the primary treatment outcome. A nonsignificant result obtained from a superiority test does not indicate that the two treatment options are similar. In other words, the lack of evidence of superiority does not guarantee a lack of difference in the performance shown by the therapies. A researcher can only demonstrate identical effects of two treatments in an equivalence trial. In a noninferiority trial, the test therapy is preferred when there is evidence about its benefits over the standard treatment in terms of secondary outcomes such as cost, adherence, and adverse effects.

CONCLUSION

Equivalence and noninferiority trials are designed differently from superiority trials. The overall quality of equivalence and noninferiority studies depends on study design and the manner in which the results are reported.

Placebo-controlled trials in pediatric urology: a cautionary view from an ethical perspective

The ethical dispute regarding placebo-controlled trials is discussed in this review. Important issues, such as clinical equipoise, fiduciary obligation and middle ground theory, are examined in the context of pediatric urology clinical research. After reviewing the literature, the authors summarize specific indications for placebo-controlled trials in pediatric urology, and emphasize that physicians have ethical and moral obligations to patients, in the sense that one should carefully plan and conduct such trials in order to gain clinically important information without exposing children to undue risks.

A covariate-adjustment regression model approach to noninferiority margin definition

To maintain the interpretability of the effect of experimental treatment (EXP) obtained from a noninferiority trial, current statistical approaches often require the constancy assumption. This assumption typically requires that the control treatment effect in the population of the active control trial is the same as its effect presented in the population of the historical trial. To prevent constancy assumption violation, clinical trial sponsors were recommended to make sure that the design of the active control trial is as close to the design of the historical trial as possible. However, these rigorous requirements are rarely fulfilled in practice. The inevitable discrepancies between the historical trial and the active control trial have led to debates on many controversial issues. Without support from a well-developed quantitative method to determine the impact of the discrepancies on the constancy assumption violation, a correct judgment seems difficult. In this paper, we present a covariate-adjustment generalized linear regression model approach to achieve two goals: (1) to quantify the impact of population difference between the historical trial and the active control trial on the degree of constancy assumption violation and (2) to redefine the active control treatment effect in the active control trial population if the quantification suggests an unacceptable violation. Through achieving goal (1), we examine whether or not a population difference leads to an unacceptable violation. Through achieving goal (2), we redefine the noninferiority margin if the violation is unacceptable. This approach allows us to correctly determine the effect of EXP in the noninferiority trial population when constancy assumption is violated due to the population difference. We illustrate the covariate-adjustment approach through a case study.

Efficacy and safety of Ayurvedic medicines: Recommending equivalence trial design and proposing safety index

Ayurvedic drugs have begun to be evaluated in controlled clinical trials. The trials, often placebo controlled, are usually designed to demonstrate superiority. Though the results have been usually reported as encouraging, statistical significance has been elusive. In this melee to show efficacy, several positive results related to safety and other purported advantages with Ayurvedic drugs, including improved quality of life, easy drug availability and less cost, get drowned. Though safety is the prime concern, efficacy ultimately matters in trials. Excellent safety profile offset modest efficacy, especially for long-term management of chronic difficult to treat disorders. There is a trade-off between efficacy and safety but we have no means to put them together in a mathematical evaluation to judge the overall performance of a drug. However, we need more suitable modern science methods/techniques to unravel the true therapeutic role of Ayurvedic drugs. We propose "equivalence trials" using modern medicine benchmark as a comparator and a "safety/tolerability index" on this perspective. We believe that several Ayurvedic drugs are capable of demonstrating equal efficacy but superior safety. Our concept may also be applicable for pragmatic trials that are more suitable for Ayurvedic therapy.

A systematic review of oxymorphone in the management of chronic pain

Opioids are recommended for control of moderate-to-severe, chronic, malignant, and nonmalignant pain. A controlled-release formulation of the opioid oxymorphone has recently been launched. The aim of this review was to assess the effectiveness of oxymorphone as an analgesic in chronic pain. A systematic search for published studies of oral oxymorphone in the management of chronic pain was conducted. The studies were evaluated for their internal validity according to standard criteria. They were also evaluated for their external validity and research ethic aspects. A meta-analysis was performed to examine the effect of oxymorphone compared with placebo. Nine studies were evaluated; three were excluded because of low quality. Six controlled studies (duration 2-12 weeks) included a total of 1489 subjects suffering from chronic low back pain, chronic pain from osteoarthritis, and chronic cancer pain. Three of the studies were of high quality and three of medium quality. External validity was assessed to be high, medium, and low (in one, three, and two studies, respectively). The meta-analysis suggests that daily doses of 40-100mg are superior to placebo; however, the estimate (reduction of pain intensity compared with placebo) of the treatment effect is imprecise (95% confidence interval -17.08, -8.69). Limited evidence suggests that oxymorphone is effective for pain control in patients with cancer. No significant differences between oxymorphone and oxycodone at equipotent doses were found. In conclusion, oxymorphone is superior to placebo. There is no evidence that the efficacy of oxymorphone differs from other opioids.

Principle standards and problems regarding proof of efficacy in clinical psychopharmacology

Proof of efficacy of a psychotropic medicinal product is the key point of clinical psychopharmacology. This especially concerns the licensing of a new compound, but apart from this special case, lots of efficacy questions need to be answered in clinical psychopharmacology, such as, e.g. the question of the efficacy of a combination therapy. The methodology of the scientific proof of efficacy has already had a long tradition and has been developed further in the recent past under different aspects. Especially the double-blind randomised parallel group comparison has been developed as a design of highest methodological standard. However, often designs have their place and justification under certain conditions and in relation to certain questions. Although in the recent past, with the over-emphasis of so-called effectiveness studies, the inherent methodological limitations of these studies have not been addressed properly (Möller in Eur Arch Psychiatry Clin Neurosci 258:257-270, 2008), which in consequence devaluated the scientific merits of the classical double-blind randomised control group study designs in the view of those colleagues, who are not that experienced in study design issues. Therefore, it seems to be timely and necessary to review the principle standards and problems concerning the proof of efficacy in clinical psychopharmacology.

Would the elderly be better off if they were given more placebos?

Placebos are useful in the medical care of the elderly, although the exact definition of a "placebo" or "placebo effect" is difficult to define precisely. They have an important role as control treatments in research trials, but a non-specific "placebo effect" may also be beneficial part of many physician-patient interactions. Physicians also give them deliberately according to several studies worldwide to satisfy patient demands or because they believe in a "placebo effect" among other reasons. A significant placebo effect has been observed among older patients in clinical trials of antidepressants (12-15%), and in treatments of Parkinson's disease (16%). Placebos activate serotonergic pathways in the brain used by antidepressants. In Parkinson's disease, the administration of a placebo stimulates dopamine release in the dorsal (resulting in motor effects) and ventral striatum (which influences expectation of reward). Much of our understanding of the placebo effect comes from studies of placebo analgesia which is influenced by conditioning, expectation, meaning and context of the treatment for the patient, and patient-physician interaction. It is anatomically medicated by brain opioid pathways. Response to "sham" acupuncture in osteoarthritis may be an example of its use in the elderly. Placebos have often been considered a deception and thus unethical. On the other hand, some physicians and ethicists have suggested conditions for appropriate uses for placebos. A placebo might offer the theoretical advantage of an inexpensive treatment that would not cause adverse drug reactions or interactions with other medications, potentially avoiding complications of polypharmacy.

The clinical investigator-subject relationship: a contextual approach

BACKGROUND

The nature of the relationship between a clinical investigator and a research subject has generated considerable debate because the investigator occupies two distinct roles: clinician and scientist. As a clinician, the investigator has duties to provide the patient with optimal care and undivided loyalty. As a scientist, the investigator has duties to follow the rules, procedures and methods described in the protocol.

RESULTS AND CONCLUSION

In this article, I present a contextual approach to the investigator-subject relationship. The extent of the investigator's duty to provide the patient/subject with clinical care can vary from one situation to the next, as a function of several factors, including: the research design, benefits and risks of the research; the subject's reasonable expectations, motivations, and vulnerabilities; the investigator's ability to benefit the subject; and the investigator's prior relationship with the subject. These and other factors need to be considered when determining the clinical investigator's obligations to provide clinical care to human research subjects. In some research contexts, the investigator has extensive clinical obligations to the patient/subject; in others, the investigator has minimal ones.

Comparison of the effects of treatment of peri-implant infection in animal and human studies: systematic review and meta-analysis

OBJECTIVE

The main objective of this systematic review is to compare the effects of treatment of peri-implant infection between animal and human studies.

MATERIAL AND METHODS

A literature search was conducted using the Medline, Cochrane Central Register of Controlled Trials, and Latin American and Caribbean Health Sciences Literature databases up to and including May 2008. In addition, bibliographies of systematic reviews on peri-implant diseases were searched manually. Non-surgical and surgical treatments of peri-implantitis/mucositis in animal models or human studies were compared. Meta-analysis was conducted to investigate the difference between the reported treatment effects in animal and human studies. Changes in probing pocket depth (PPD) and probing attachment level (PAL) from baseline measurements were used as measures of outcome. Single-level and multilevel meta-regression analysis was performed by taking into account the different follow-up times of the studies included.

RESULTS

The single-level and multilevel random-effects meta-analysis showed that the difference in PPD reduction [0.31 mm, 95% confidence interval (CI): -0.27, 0.88] and in PAL gain (0.21 mm, 95% CI: -0.47, 0.88) between animal and human studies was not statistically significant. The random-effects meta-regression suggested that studies with longer follow-up times revealed greater PPD reduction (0.25 mm per month, 95% CI: 0.14, 0.35). However, when the different follow-up times were taken into account, these differences became greater. Substantial heterogeneity between studies was found in the meta-analyses (I(2)=97.6% for animal studies and 99.9% for human studies).

CONCLUSION

There was great heterogeneity between human and animal studies in terms of study designs and treatment procedures. Therefore, the results from this meta-analysis should be interpreted with caution. Heterogeneity between studies and its causes merit further investigations.

Why do individuals agree to enrol in clinical trials? A qualitative study of health research participation in Blantyre, Malawi

Current literature suggests that therapeutic misconception a belief by participants in a clinical trial that they are in fact simply being given clinical care is common, especially among illiterate populations in developing countries. Therapeutic misconception reects problems in informed consent, as people agree to participate in clinical trials without being aware that the trial procedures and test products may not in fact benet them. In this study of Malawian adults who had participated in research projects of various kinds during the preceding years, we found that the majority participated in research for the sake of obtaining better quality treatment made available through the clinical trials as ancillary care. Their consent to participate was not due to a belief that the actual procedures of the trial would directly benet their health. Respondents indicated that, government hospitals being crowded and commonly lacking drugs, they agreed to take part in research projects in the hope of obtaining access to ancillary care provided by clinical trials. We conclude that in this environment, possibly owing to inadequacy of routine health services, people make rational decisions to participate in research. We question whether the term therapeutic misconception accurately describes participants motivation under conditions of limited resources. We also discuss the relevance of these ndings for understanding undue inducement in clinical trials.

Ethical and Scientific Perspectives of Placebo-controlled Trials in Schizophrenia

Clinical trials for development of new medications are essential in all fields of medicine. The requirement for a placebo arm in pharmaceutical trials presents ethical and clinical dilemmas that are especially complicated with regard to mentally ill persons whose free choice and ability to provide informed consent may be questionable. On the other hand, we do not believe that this predicament justifies unconditional rejection of placebo use in psychiatry, when the investigational drug may ultimately provide substantial benefit for some patients. At the same time it is the psychiatrist's responsibility to insure that investigators are adequately trained to conduct clinical trials and that stringent regulatory committees supervise the scientific, clinical and ethical aspects of the trials.

KEYWORDS

Placebo-control; Schizophrenia; Medical ethics; Clinical trials.

A most stubborn bias: no adjustment method fully resolves confounding by indication in observational studies

OBJECTIVE

To evaluate the effectiveness of methods that control for confounding by indication, we compared breast cancer recurrence rates among women receiving adjuvant chemotherapy with those who did not.

STUDY DESIGN AND SETTING

In a medical record review-based study of breast cancer treatment in older women (n=1798) diagnosed between 1990 and 1994, our crude analysis suggested that adjuvant chemotherapy was positively associated with recurrence (hazard ratio [HR]=2.6; 95% confidence interval [CI]=1.9, 3.5). We expected a protective effect, so postulated that the crude association was confounded by indications for chemotherapy. We attempted to adjust for this confounding by restriction, multivariable regression, propensity scores (PSs), and instrumental variable (IV) methods.

RESULTS

After restricting to women at high risk for recurrence (n=946), chemotherapy was not associated with recurrence (HR=1.1; 95% CI=0.7, 1.6) using multivariable regression. PS adjustment yielded similar results (HR=1.3; 95% CI=0.8, 2.0). The IV-like method yielded a protective estimate (HR=0.9; 95% CI=0.2, 4.3); however, imbalances of measured factors across levels of the IV suggested residual confounding.

CONCLUSION

Conventional methods do not control for unmeasured factors, which often remain important when addressing confounding by indication. PS and IV analysis methods can be useful under specific situations, but neither method adequately controlled confounding by indication in this study.

Increased physical activity in abdominally obese women through support for changed commuting habits: a randomized clinical trial

BACKGROUND

Abdominally obese women can reduce their health risk through regular physical activity. There is, however, little evidence on the effectiveness of interventions that promote physical activity long-term, such as cycling and walking to and from work.

METHODS

This intervention focused on physically active commuting (cycling and walking) in middle-aged (30-60 years), abdominally obese (waist circumference > or = 88 cm) women (n=120), recruited by newspaper advertisement. The intervention group was a moderate-intensity programme with physician meetings, physical activity prescriptions, group counselling and bicycles. The control group was a low-intensity group support programme with pedometers. We used a randomized, controlled, 2-armed design with 18 months duration and intention-to-treat analysis (data collection 2005-2006). Treatment success was defined as bicycling > or = 2 km/d (primary) or walking 10,000 steps per day (secondary).

RESULTS

At baseline, mean (s.d.) age was 48.2 years (7.4), waist circumference 103.8 cm (7.8), walking 8471 steps per day (2646), bicycling 0 km per day. Attrition at 18 months was 10% for the intervention group and 25% in the control group (P=0.03). The intervention group was more likely to achieve treatment success for cycling than controls: 38.7 vs 8.9% (odds ratio (OR)=7.8 (95% confidence interval=4.0 to 15.0, P<0.001)), but with no difference for compliance with the walking recommendation: 45.7 vs 39.3% (OR=1.2 (95% CI=0.7 to 2.0, P=0.50)). Commuting by car and public transport were reduced by 34% (P<0.01) and 37% (P<0.001), respectively, with no differences between groups. Both groups attained similar waist reductions (-2.1 and -2.6 cm, P=0.72).

CONCLUSIONS

Abdominally obese women can increase PA long-term through moderate-intensity behavioural support aimed at changing commuting habits.

Review of the efficacy of placebo in comparative clinical trials between typical and atypical antipsychotics

OBJECTIVE: To review the efficacy of placebo in comparison with atypical and typical antipsychotics for the treatment of schizophrenia and schizoaffective disorder and to evaluate the pertinence of using placebo in clinical trials with antipsychotics. METHOD: Trials in which the atypical antipsychotics were compared with typical antipsychotics and placebo were included. A search was conducted using the terms "amisulpride", "aripiprazole", "clozapine", "olanzapine", "quetiapine", "risperidone", "sertindole", "ziprasidone" and "zotepine". Main efficacy parameters were calculated using the proportion of "events" (defined as a deterioration or lack of improvement by at least 20% in Positive and Negative Syndrome Scale or Brief Psychiatric Rating Scale) and the pooled relative risk with random effects, with their respective 95% confidence intervals. We also calculated the necessary sample sizes in studies in which the study drug is compared to a typical antipsychotic or placebo. RESULTS: The pooled efficacy rates observed were 40.8%, 34.9% and 21.3% for the atypical antipsychotics, typical antipsychotics and placebo, respectively. One hundred and sixty six patients would have to be included when a new drug is compared with placebo if calculation is based on a difference of 20% found between the atypical antipsychotic and placebo and 2,054 if the difference sought were that found between the atypical antipsychotic and the typical antipsychotic, i.e. 6%. The estimated therapeutic failures would be 115 of the 166 patients when the study drug is compared with placebo, and 1,274 failures in the 2,054 patients when the study drug is compared to the typical antipsychotic. CONCLUSIONS: Placebo controlled studies may reduce the number of individuals exposed to the harmful effects of ineffective drugs.

Ethical concerns about non-active conditions in smoking cessation trials and methods to decrease such concerns

Many have questioned whether it is ethical to assign participants in a research trial to a non-active control condition (e.g., a placebo or attention-only control) when (a) the disorder under study is serious, (b) validated treatment is available, and (c) harm may occur if treatment is not given. This ethical concern may apply to studies of controlled trials of treatments for drug dependence. The current paper examines this concern for trials of nicotine dependence because there are multiple validated treatments available. The major harm from assignment to a non-active condition in such a trial could occur if failure to quit discourages smokers from trying to quit again. Whether this harm actually occurs is unclear. Potential harms from non-active conditions may be mitigated by (a) provision of more explicit information in the consent process, (b) inclusion of only those who have failed optimal treatment, (c) provision of validated treatment via a different modality, (d) tests of the new treatment as an add-on to standard treatment, (e) use of dose-response design, (f) use of unequal randomization designs, (g) use of stopping rules, (h) provision of optimal therapy to those who fail during the study, or (i) comparison of the experimental treatment vs. standard treatment. Empirical research to inform ethical analysis of non-active conditions in drug abuse research is suggested.

Inhaled drugs to reduce exacerbations in patients with chronic obstructive pulmonary disease: a network meta-analysis

BACKGROUND

Most patients with chronic obstructive pulmonary disease (COPD) receive inhaled long-acting bronchodilators and inhaled corticosteroids. Conventional meta-analyses established that these drugs reduce COPD exacerbations when separately compared with placebo. However, there are relatively few head-to-head comparisons and conventional meta-analyses focus on single comparisons rather than on a simultaneous analysis of competing drug regimens that would allow rank ordering of their effectiveness. Therefore we assessed, using a network meta-analytic technique, the relative effectiveness of the common inhaled drug regimes used to reduce exacerbations in patients with COPD.

METHODS

We conducted a systematic review and searched existing systematic reviews and electronic databases for randomized trials of >/= 4 weeks' duration that assessed the effectiveness of inhaled drug regimes on exacerbations in patients with stable COPD. We extracted participants and intervention characteristics from included trials and assessed their methodological quality. For each treatment group we registered the proportion of patients with >/= 1 exacerbation during follow-up. We used treatment-arm based logistic regression analysis to estimate the absolute and relative effects of inhaled drug treatments while preserving randomization within trials.

RESULTS

We identified 35 trials enrolling 26,786 patients with COPD of whom 27% had >/= 1 exacerbation. All regimes reduced exacerbations statistically significantly compared with placebo (odds ratios ranging from 0.71 (95% confidence interval [CI] 0.64 to 0.80) for long-acting anticholinergics to 0.78 (95% CI 0.70 to 0.86) for inhaled corticosteroids). Compared with long-acting bronchodilators alone, combined treatment was not more effective (comparison with long-acting beta-agonists: odds ratio 0.93 [95% CI 0.84 to 1.04] and comparison with long-acting anticholinergics: odds ratio 1.02 [95% CI 0.90 to 1.16], respectively). If FEV1 was </= 40% predicted, long-acting anticholinergics, inhaled corticosteroids, and combination treatment reduced exacerbations significantly compared with long-acting beta-agonists alone, but not if FEV1 was > 40% predicted. This effect modification was significant for inhaled corticosteroids (P = 0.02 for interaction) and combination treatment (P = 0.01) but not for long-acting anticholinergics (P = 0.46). A limitation of this analysis is its exclusive focus on exacerbations and lack of FEV1 data for individual patients.

CONCLUSION

We found no evidence that one single inhaled drug regimen is more effective than another in reducing exacerbations. Inhaled corticosteroids when added to long-acting beta-agonists reduce exacerbations only in patients with COPD with FEV1 </= 40%.

Do patients with alcohol dependence respond to placebo? Results from the COMBINE Study

OBJECTIVE

The purpose of this study was to examine the nature of the effect of placebo medication plus accompanying medical management in the treatment of alcohol dependence.

METHOD

The National Institute on Alcohol Abuse and Alcoholism COMBINE (Combining Medications and Behavioral Interventions) study, a randomized controlled double-blind trial of 1,383 alcohol-dependent patients, compared combinations of medications (acamprosate [Campral] and naltrexone [ReVia]) and behavioral therapy (medical management and specialist-delivered behavioral therapy) for alcohol dependence. This report focuses on a subset of that study population (n = 466) receiving (1) specialized behavioral therapy alone (without pills), (2) specialized behavioral therapy + placebo medication + medical management, or (3) placebo + medical management.

RESULTS

During 16 weeks of treatment, participants receiving behavioral therapy alone had a lower percentage of days abstinent (66.6%) than did the participants receiving placebo and medical management (73.1%) or those receiving specialized behavioral therapy + placebo + medical management (79.4%). The group receiving behavioral therapy alone relapsed to heavy drinking more often (79.0%) than those receiving behavioral therapy + placebo + medical management (71.2%). This report focuses on potential explanations for this finding. The two groups of participants receiving placebo + medical management were more likely to attend Alcoholics Anonymous meetings during treatment (32.7% and 32.0% vs 20.4%) and were less likely to withdraw from treatment (14.1% and 22.9% vs 29.3%).

CONCLUSIONS

There appeared to be a significant "placebo effect" in the COMBINE Study, consisting of pill taking and seeing a health care professional. Contributing factors to the placebo response may have included pill taking itself, the benefits of meeting with a medical professional, repeated advice to attend Alcoholics Anonymous, and optimism about a medication effect.