Randomised study of n of 1 trials versus standard practice

N-of-1 trials to facilitate evidence-based deprescribing: Rationale and case study

Deprescribing has emerged as an important aspect of patient-centred medication management but is vastly underutilized in clinical practice. The current narrative review will describe an innovative patient-centred approach to deprescribing-N-of-1 trials. N-of-1 trials involve multiple-period crossover design experiments conducted within individual patients. They enable patients to compare the effects of two or more treatments or, in the case of deprescribing N-of-1 trials, continuation with a current treatment versus no treatment or placebo. N-of-1 trials are distinct from traditional between-patient studies such as parallel-group or crossover designs which provide an average effect across a group of patients and obscure differences between individuals. By generating data on the effect of an intervention for the individual rather than the population, N-of-1 trials can promote therapeutic precision. N-of-1 trials are a particularly appealing strategy to inform deprescribing because they can generate individual-level evidence for deprescribing when evidence is uncertain, and can thus allay patient and physician concerns about discontinuing medications. To illustrate the use of deprescribing N-of-1 trials, we share a case example of an ongoing series of N-of-1 trials that compare maintenance versus deprescribing of beta-blockers in patients with heart failure with preserved ejection fraction. By providing quantifiable data on patient-reported outcomes, promoting personalized pharmacotherapy, and facilitating shared decision making, N-of-1 trials represent a potentially transformative strategy to address polypharmacy.

Conduct and Implementation of Personalized Trials in Research and Practice

The mainstay of evidence development in medicine is the parallel-group randomized controlled trial (RCT), which generates estimates of treatment efficacy or effectiveness for the average person in the trial. In contrast, personalized trials (sometimes referred to as 'single-person trials' or 'N-of-1 trials') assess the comparative effectiveness of two or more treatments in a single individual. These single-subject, randomized crossover trials have been used in a scattershot fashion in medicine for over 40 years but have not been widely adopted. An important barrier is the paucity of strong evidence that personalized trials improve outcomes. However, the principal impediment may have less to do with proof of efficacy than with practical aspects of design and implementation. These include decisions about treatment regimen flexibility, blinding, and washout periods as well as organizational, clinician, and patient-level challenges. After reviewing the essential elements of personalized trials, this article addresses these speed bumps and fundamentally asks, 'Why have personalized trials not been more widely adopted, and how can they be made more readily deployable and useful?' The article concludes by suggesting ways in which emerging technologies and approaches promise to overcome existing barriers and open promising vistas for the next generation of personalized-trial researchers and practitioners.

A scoping review of randomized trials assessing the impact of n-of-1 trials on clinical outcomes

BACKGROUND

The single patient (n-of-1) trial can be used to resolve therapeutic uncertainty for the individual patient. Treatment alternatives are systematically tested against each other, generating patient-specific data used to inform an individualized treatment plan. We hypothesize that clinical decisions informed by n-of-1 trials improve patient outcomes compared to usual care. Our objective was to provide an overview of the clinical trial evidence on the effect of n-of-1 trials on clinical outcomes.

METHODS

A systematic search of medical databases, trial registries, and gray literature was performed to identify trials assessing clinical outcomes in a group of patients undergoing an n-of-1 trial compared to those receiving usual care for any clinical condition. We abstracted elements related to study design and results and assessed risk of bias for both the overall randomized trials and the n-of-1 trials. The review was registered on PROSPERO. (CRD: 42020166490).

FINDINGS

Twelve randomized trials of the n-of-1 approach were identified in conditions spanning chronic pain, osteoarthritis, chronic irreversible airflow limitation, attention-deficit hyperactivity disorder, hyperlipidemia, atrial fibrillation, statin intolerance, and hypertension. One trial showed a statistically significant benefit in the primary outcome. Only one reached the pre-specified sample size target. Secondary outcomes showed modest benefits, including decreasing medication use, fewer atrial fibrillation episodes, and improved patient satisfaction.

INTERPRETATION

Very few trials have been undertaken to assess the effectiveness of n-of-1 trials in improving clinical outcomes, and most trials were underpowered for the primary outcome. Barriers to enrollment and retention in these trials should be explored, as well-powered randomized trials are needed to clarify the clinical impact of n-of-1 trials and assess their utility in clinical practice.

Individualized therapy trials: navigating patient care, research goals and ethics

'Individualized therapy' trials (sometimes called n-of-1 trials) use patients as their own controls to evaluate treatments. Here we divide such trials into three categories: multi-crossover trials aimed at individual patient management, multi-crossover trial series and pre-post trials. These trials all customize interventions for patients; however, the latter two categories also aim to inform medical practice and thus embody tensions between the goals of care and research that are typical of other types of clinical trials. In this Perspective, we discuss four domains where such tensions play out-clinical equipoise, informed consent, reporting and funding, and we provide recommendations for addressing each.

Single-Subject Research in Psychiatry: Facts and Fictions

Scientific evidence in the field of psychiatry is mainly derived from group-based ("nomothetic") studies that yield group-aggregated results, while often the need is to answer questions that apply to individuals. Particularly in the presence of great inter-individual differences and temporal complexities, information at the individual-person level may be valuable for personalized treatment decisions, individual predictions and diagnostics. The single-subject study design can be used to make inferences about individual persons. Yet, the single-subject study is not often used in the field of psychiatry. We believe that this is because of a lack of awareness of its value rather than a lack of usefulness or feasibility. In the present paper, we aimed to resolve some common misconceptions and beliefs about single-subject studies by discussing some commonly heard "facts and fictions." We also discuss some situations in which the single-subject study is more or less appropriate, and the potential of combining single-subject and group-based study designs into one study. While not intending to plea for single-subject studies at the expense of group-based studies, we hope to increase awareness of the value of single-subject research by informing the reader about several aspects of this design, resolving misunderstanding, and providing references for further reading.

Making the switch: From case studies to N-of-1 trials

Case studies can generate hypothesis based on unique clinical patient encounters and provide guidance among populations with limited numbers of patients. However, case studies are not blinded and are susceptible to a variety of factors that can influence study outcomes. One potential solution to minimize this bias is to use an N-of-1 trial. N-of-1 trials are a double-blinded randomized crossover trial within a limited number of patients, often as small as a single patient. These trials borrow many concepts from randomized controlled trials (RCTs), which in turn increases the validity of findings compared with a case report. Situations best suited for an N-of-1 trial include chronic disease states and therapies with quick onset and offset, such as in patients with seizures. There are many opportunities to use N-of-1 trials among patients with epilepsy, and providers are encouraged to explore and employ these methods. The purpose of this article was to describe N-of-1 trials along with considerations for conducting, publishing, and evaluating N-of-1 trials.

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The use of N-of-1 trials can minimize bias found in traditional case studies.

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N-of-1 trials are a double-blinded randomized crossover trial within a single patient.

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There are methods and reporting standards to guide the development and interpretation of N-of-1 trials.

Demonstrating Heterogeneity of Treatment Effects Among Patients: An Overlooked but Important Step Toward Precision Medicine

Although heterogeneity in the observed outcomes in clinical trials is often assumed to reflect a true heterogeneous response, it could actually be due to random variability. This retrospective analysis of four randomized, double-blind, placebo-controlled multiperiod (i.e., episode) crossover trials of fentanyl for breakthrough cancer pain illustrates the use of multiperiod crossover trials to examine heterogeneity of treatment response. A mixed-effects model, including fixed effects for treatment and episode and random effects for patient and treatment-by-patient interaction, was used to assess the heterogeneity in patients' responses to treatment during each episode. A significant treatment-by-patient interaction was found for three of four trials (P < 0.05), suggesting heterogeneity of the effect of fentanyl among different patients in each trial. Similar analyses in other therapeutic areas could identify conditions and therapies that should be investigated further for predictors of treatment response in efforts to maximize the efficiency of developing precision medicine strategies.

Research methods in complementary and alternative medicine: an integrative review

The scientific literature presents a modest amount of evidence in the use of complementary and alternative medicine (CAM). On the other hand, in practice, relevant results are common. The debates among CAM practitioners about the quality and execution of scientific research are important. Therefore, the aim of this review is to gather, synthesize and describe the differentiated methodological models that encompass the complexity of therapeutic interventions. The process of bringing evidence-based medicine into clinical practice in CAM is essential for the growth and strengthening of complementary medicines worldwide.

N-of-1 trials for assessing the effects of deprescribing medications on short-term clinical outcomes in older adults: a systematic review

OBJECTIVES

The objective of this study was to determine the applicability of utilizing the N-of-1 method for deprescribing trials in older adults.

STUDY DESIGN AND SETTING

Systematic review of any human studies conducted in older adults (≥50 years), deprescribing any long-term treatment over less than a year using the N-of-1 trial method was performed. Two authors independently reviewed all articles for eligibility and extracted data. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Quality assessment of trials was carried out using the Physiotherapy Evidence Database scale.

RESULTS

Six studies were identified and extracted. Trials investigated the efficacy of pharmacological and non-pharmacological therapies for treating diseases. Four trials demonstrated non-significant benefits of treatment, with a significant number of patients discontinuing their medications in two trials where follow-up data was collected (N = 8/18, 9/14 [44.4--64.3%]). In two studies, where treatment was beneficial, all participants were found to be maintaining regimen at follow-up.

CONCLUSION

The N-of-1 trial methodology can be used to generate patient-specific evidence of medication and inform prescribing decisions. Future studies are required to assess the feasibility of using the N-of-1 method to determine the effects of deprescribing medications on short-term outcomes.

N of 1 trials and the optimal individualisation of drug treatments: a systematic review protocol

BACKGROUND

Guidelines and evidence-based drug treatment recommendations are usually based on the results of clinical trials, which have limited generalisability in routine clinical settings due to their restrictive eligibility criteria. These trials are also conducted in ideal and rigorously controlled settings. N of 1 trials, which are single patient multiple crossover studies, offer a means of increasing the evidence base and individualising care for individuals in clinical practice. This systematic review of the N of 1 drug treatment trial aims to investigate its usefulness for achieving optimal individualised patient care.

METHODS

The following databases will be searched for relevant articles: MEDLINE, EMBASE, PsycINFO (all via Ovid), AMED, CINAHAL (via EBSCO), The Cochrane Library (including CENTRAL, NHS EED, and DARE), and Web of Science (Thomson Reuters). Supplementary searches will include ongoing trial databases and organisational websites. All N of 1 trials in which patients have been treated with a drug will be considered. Outcomes will include information on the clinical usefulness of N of 1 trials-i.e. achievement of optimal individualised care, health-care utilisation of patients, frequently used practices, experiences of clinical care or participation in N of 1 trials, adherence to treatment plan, and unwanted effects of the treatment. Screening of included papers will be undertaken independently by two reviewers, while data extraction and the quality of reporting will be conducted by one reviewer and checked by another. Both quantitative and qualitative summaries will be reported using appropriate methods.

DISCUSSION

This review will provide new insights into the clinical utility of N of 1 drug trials in helping participants find the most acceptable treatment as defined by patients and clinicians based on the selected outcome measures and the perspectives of participants involved in such trials. Findings from this review will inform the development of a stakeholder workshop and guidance to help physicians find the optimum therapy for their patients and will help guide future research on N of 1 trials.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016032452.

Outcomes for patients with the same disease treated inside and outside of randomized trials: a systematic review and meta-analysis

BACKGROUND

It is unclear whether participation in a randomized controlled trial (RCT), irrespective of assigned treatment, is harmful or beneficial to participants. We compared outcomes for patients with the same diagnoses who did ("insiders") and did not ("outsiders") enter RCTs, without regard to the specific therapies received for their respective diagnoses.

METHODS

By searching the MEDLINE (1966-2010), Embase (1980-2010), CENTRAL (1960-2010) and PsycINFO (1880-2010) databases, we identified 147 studies that reported the health outcomes of "insiders" and a group of parallel or consecutive "outsiders" within the same time period. We prepared a narrative review and, as appropriate, meta-analyses of patients' outcomes.

RESULTS

We found no clinically or statistically significant differences in outcomes between "insiders" and "outsiders" in the 23 studies in which the experimental intervention was ineffective (standard mean difference in continuous outcomes -0.03, 95% confidence interval [CI] -0.1 to 0.04) or in the 7 studies in which the experimental intervention was effective and was received by both "insiders" and "outsiders" (mean difference 0.04, 95% CI -0.04 to 0.13). However, in 9 studies in which an effective intervention was received only by "insiders," the "outsiders" experienced significantly worse health outcomes (mean difference -0.36, 95% CI -0.61 to -0.12).

INTERPRETATION

We found no evidence to support clinically important overall harm or benefit arising from participation in RCTs. This conclusion refutes earlier claims that trial participants are at increased risk of harm.

A new generation of pragmatic trials of psychosocial interventions is needed

This Editorial addresses the crucial issue of which research methodology is most suited for capturing the complexity of psychosocial interventions conducted in 'real world' mental health settings. It first examines conventional randomized controlled trial (RCT) methodology and critically appraises its strengths and weaknesses. It then considers the specificity of mental health care treatments and defines the term 'complex' intervention and its implications for RCT design. The salient features of pragmatic RCTs aimed at generating evidence of psychosocial intervention effectiveness are then described. Subsequently, the conceptualization of pragmatic RCTs, and of their further developments - which we propose to call 'new generation' pragmatic trials - in the broader routine mental health service context, is explored. Helpful tools for planning pragmatic RCTs, such as the CONSORT extension for pragmatic trials, and the PRECIS tool are also examined. We then discuss some practical challenges that are involved in the design and implementation of pragmatic trials based on our own experience in conducting the GET UP PIANO Trial. Lastly, we speculate on the ways in which current ideas on the purpose, scope and ethics of mental health care research may determine further challenges for clinical research and evidence-based practice.

Overcoming implementation challenges of personalized cancer therapy

Personalized cancer therapy is based on the precept that detailed molecular characterization of the patient's tumour and its microenvironment will enable tailored therapies to improve outcomes and decrease toxicity. The goal of personalized therapy is to target aberrations that drive tumour growth and survival, by administering the right drug combination for the right person. This is becoming increasingly achievable with advances in high-throughput technologies to characterize tumours and the expanding repertoire of molecularly targeted therapies. However, there are numerous challenges that need to be surpassed before delivering on the promise of personalized cancer therapy. These include tumour heterogeneity and molecular evolution, costs and potential morbidity of biopsies, lack of effective drugs against most genomic aberrations, technical limitations of molecular tests, and reimbursement and regulatory hurdles. Critically, the 'hype' surrounding personalized cancer therapy must be tempered with realistic expectations, which, today, encompass increased survival times for only a portion of patients.

N-of-1 trials in the medical literature: a systematic review

BACKGROUND

N-of-1 trials (multiple crossover studies conducted in single individuals) may be ideal for determining individual treatment effects and as a tool to estimate heterogeneity of treatment effects (HTE) in a population. However, comprehensive data on n-of-1 trial methodology and analysis is lacking. We performed this study to describe n-of-1 trial characteristics, examine treatment changes resulting from n-of-1 trial participation, and to determine if trial reporting is adequate for estimating HTE.

METHODS

We undertook a systematic review of n-of-1 trials published between 1985 and December 2010. Included trials were those having individual treatment episodes as the unit of randomization and reporting individual-specific treatment effects. We abstracted trial characteristics, treatment change information, and analytic methods.

RESULTS

We included 108 trials reporting on 2154 participants. Approximately half (49%) of the trials used a statistical cutoff to determine a superior treatment, whereas the remainder used a graphical comparison (25%) or a clinical significance cutoff (20%). Sixty-seven trials, reporting on 488 people, provided treatment change information: 54% of participants had subsequent treatment decisions consistent with the results of the trial, 8% had decisions inconsistent with trial results, and 38% had ambiguous results. Less than half of the trials (45%) reported adequate information to facilitate the calculation of HTE.

CONCLUSION

N-of-1 trials are a useful tool for enhancing therapeutic precision in a range of conditions and should be conducted more often. To facilitate future meta-analysis, and the estimation of HTE, researchers reporting n-of-1 trial results should clearly describe individual data.

The n-of-1 clinical trial: the ultimate strategy for individualizing medicine?

N-of-1 or single subject clinical trials consider an individual patient as the sole unit of observation in a study investigating the efficacy or side-effect profiles of different interventions. The ultimate goal of an n-of-1 trial is to determine the optimal or best intervention for an individual patient using objective data-driven criteria. Such trials can leverage study design and statistical techniques associated with standard population-based clinical trials, including randomization, washout and crossover periods, as well as placebo controls. Despite their obvious appeal and wide use in educational settings, n-of-1 trials have been used sparingly in medical and general clinical settings. We briefly review the history, motivation and design of n-of-1 trials and emphasize the great utility of modern wireless medical monitoring devices in their execution. We ultimately argue that n-of-1 trials demand serious attention among the health research and clinical care communities given the contemporary focus on individualized medicine.

Selecting a change and evaluating its impact on the performance of a complex adaptive health care delivery system

Complexity science suggests that our current health care delivery system acts as a complex adaptive system (CAS). Such systems represent a dynamic and flexible network of individuals who can coevolve with their ever changing environment. The CAS performance fluctuates and its members' interactions continuously change over time in response to the stress generated by its surrounding environment. This paper will review the challenges of intervening and introducing a planned change into a complex adaptive health care delivery system. We explore the role of the "reflective adaptive process" in developing delivery interventions and suggest different evaluation methodologies to study the impact of such interventions on the performance of the entire system. We finally describe the implementation of a new program, the Aging Brain Care Medical Home as a case study of our proposed evaluation process.

Outcomes of patients who participate in randomized controlled trials compared to similar patients receiving similar interventions who do not participate

BACKGROUND

Some people believe that patients who take part in randomised controlled trials (RCTs) face risks that they would not face if they opted for non-trial treatment. Others think that trial participation is beneficial and the best way to ensure access to the most up-to-date physicians and treatments. This is an updated version of the original Cochrane review published in Issue 1, 2005.

OBJECTIVES

To assess the effects of patient participation in RCTs ('trial effects') independent both of the effects of the clinical treatments being compared ('treatment effects') and any differences between patients who participated in RCTs and those who did not. We aimed to compare similar patients receiving similar treatment inside and outside of RCTs.

SEARCH STRATEGY

In March 2007, we searched The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, The Cochrane Methodology Register, SciSearch and PsycINFO for potentially relevant studies. Our search yielded 7586 new references. In addition, we reviewed the reference lists of relevant articles.

SELECTION CRITERIA

Randomized studies and cohort studies with data on clinical outcomes of RCT participants and similar patients who received similar treatment outside of RCTs.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies for inclusion, assessed study quality and extracted data.

MAIN RESULTS

We identified 30 new non-randomized cohort studies (45 comparisons): no new RCTs were found. This update now includes five RCTs (yielding 6 comparisons) and 80 non-randomized cohort studies (130 comparisons), with 86,640 patients treated in RCTs and 57,205 patients treated outside RCTs. In the randomised studies, patients were invited to participate in an RCT or not; these comparisons provided limited information because of small sample sizes (a total of 412 patients) and the nature of the questions they addressed. When the results of RCTs and non-randomized cohorts that reported dichotomous outcomes were combined, there were 98 comparisons; there was also heterogeneity (P < 0.00001, I(2) = 42.2%) between studies. No statistical significant differences were found for 85 of the 98 comparisons. Eight comparisons reported statistically significant better outcomes for patients treated within RCTs, and five comparisons reported statistically significant worse outcomes for patients treated within RCTs. There was significant heterogeneity (P < 0.00001, I(2) = 58.2%) among the 38 continuous outcome comparisons. No statistically significant differences were found for 30 of the 38 comparisons. Three comparisons reported statistically significant better outcomes for patients treated within RCTs, and five comparisons reported statistically significant worse outcomes for patients treated within RCTs.

AUTHORS' CONCLUSIONS

This review indicates that participation in RCTs is associated with similar outcomes to receiving the same treatment outside RCTs. These results challenge the assertion that the results of RCTs are not applicable to usual practice.

Outcomes of patients who participate in randomised controlled trials compared to similar patients receiving similar interventions who do not participate

BACKGROUND

Some people believe that patients who take part in randomised controlled trials (RCTs) face risks that they would not face if they opted for non-trial treatment. Others think that trial participation is beneficial and the best way to ensure access to the most up to date physicians and treatments.

OBJECTIVES

To assess the effects of patient participation in RCTs ('trial effects') independent both of the effects of the clinical treatments being compared ('treatment effects') and any differences between patients who participated in RCTs and those who did not.

SEARCH STRATEGY

In May 2001, we searched The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, The Cochrane Methodology Register, SciSearch and PsycINFO for potentially relevant studies. Our search yielded over 10,000 references. In addition, we reviewed the reference lists of relevant articles and wrote to over 250 investigators to try to obtain further information.

SELECTION CRITERIA

Randomised studies and cohort studies with data on clinical outcomes of RCT participants and similar patients who received similar treatment outside of RCTs.

DATA COLLECTION AND ANALYSIS

At least two reviewers independently assessed studies for inclusion, assessed study quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

We included five randomised studies (yielding 6 comparisons) and 50 non-randomised cohort studies (85 comparisons), with 31,140 patients treated in RCTs and 20,380 patients treated outside RCTs. In the randomised studies, patients were invited to participate in an RCT or not; these comparisons provided limited information because of small sample sizes (a total of 412 patients) and the nature of the questions they addressed. There was statistically significant heterogeneity (P < 0.002, I(2) = 36.2%) among the 73 dichotomous outcome comparisons; none of the potential explanatory factors we investigated helped to explain this heterogeneity. No statistically significant differences were found for 63 of the 73 comparisons. Eight comparisons reported statistically significant better outcomes for patients treated within RCTs, and two comparisons reported statistically significant worse outcomes for patients treated within RCTs. There were no statistically significant differences in heterogeneity (P = 0.53, I(2) = 0%) or in outcomes (SMD 0.01, 95% CI -0.10 to 0.12) of patients treated within and outside RCTs in the 18 comparisons which had used continuous outcomes.

AUTHORS' CONCLUSIONS

This review indicates that participation in RCTs is not associated with greater risks than receiving the same treatment outside RCTs. These results challenge the assertion that the results of RCTs are not applicable to usual practice.

Evidence-based practice in clinical psychology: What it is, why it matters; what you need to know

The history and meaning of evidence-based practice (EBP) in the health disciplines was described to the Council of University Directors of Clinical Psychology (CUDCP) training programs. Evidence-based practice designates a process of clinical decision-making that integrates research evidence, clinical expertise, and patient preferences and characteristics. Evidence-based practice is a transdisciplinary, idiographic approach that promotes lifelong learning. Empirically supported treatments (ESTs) are an important component of EBP, but EBP cannot be reduced to ESTs. Psychologists need additional skills to act as creators, synthesizers, and consumers of research evidence, who act within their scope of clinical expertise and engage patients in shared decision-making. Training needs are identified in the areas of clinical trial methodology and reporting, systematic reviews, search strategies, measuring patient preferences, and acquisition of clinical skills to perform ESTs.

An n-of-1 trial service in clinical practice: testing the effectiveness of stimulants for attention-deficit/hyperactivity disorder

OBJECTIVE

We sought to describe the clinical use of n-of-1 trials for attention-deficit/hyperactivity disorder in publicly and privately funded family and specialized pediatric practice in Australia.

METHODS

We used a within-patient randomized, double-blind, crossover comparison of stimulant (dexamphetamine or methylphenidate) versus placebo or alternative stimulant using 3 pairs of treatment periods. Trials were conducted from a central location using mail and telephone communication, with local supervision by the patients' clinicians.

PATIENTS

Our study population included children with clinically diagnosed attention-deficit/hyperactivity disorder who were aged 5 to 16 years and previously stabilized on an optimal dose of stimulant. They were selected because treatment effectiveness was uncertain.

MAIN OUTCOME MEASURES

Our measures included number of patients recruited, number of doctors who used the service, geographic spread, completion rates, response rate, and post-n-of-1 trial decisions.

RESULTS

Forty-five doctors across Australia requested 108 n-of-1 trials, of which 86 were completed. In 69 drug-versus-placebo comparisons, 29 children responded better to stimulant than placebo. Immediately posttrial, 19 of 25 drug-versus-placebo responders stayed on the same stimulant, and 13 of 24 nonresponders ceased or switched stimulants. In 40 of 63 for which data were available, posttrial management was consistent with the trial results. For all types of n-of-1 trials, management changed for 28 of 64 children for whom information was available.

DISCUSSION

Attention-deficit/hyperactivity disorder n-of-1 trials can be implemented successfully by mail and telephone communication. This type of trial can be valuable in clarifying treatment effect when it is uncertain, and in this series, they had a noticeable impact on short-term management.

N-of-1 trials: innovative methods to evaluate complementary and alternative medicines in pediatric cancer

N-of-1 randomized controlled trials (RCTs) are randomized trials conducted within individuals and may be an attractive methodology for conducting studies of complementary and alternative medicine (CAM) in pediatric oncology. These trials may be used to determine the efficacy of an intervention in an individual, or multiple N-of-1 RCTs may be combined to estimate a population effect. There are many potential advantages to the use of N-of-1 RCTs with CAM in pediatric cancer. These advantages include the ability to determine whether CAM is effective in a specific child. In addition, the N-of-1 RCT allows parents and children to voice preferences about treatment options and allows them to directly participate in balancing adverse events and therapeutic benefits. Also, in estimation of population effects, combining multiple N-of-1 RCTs tends to require smaller sample sizes than do traditional parallel-group designs. However, there also may be several challenges to the conduct of such a trial. The use of N-of-1 RCTs may be very beneficial in evaluating CAM therapies in pediatric cancer. However, careful consideration of the advantages and disadvantages of such a design should be undertaken prior to initiating an N-of-1 RCT.

Systematic review to determine whether participation in a trial influences outcome

OBJECTIVE

To systematically compare the outcomes of participants in randomised controlled trials (RCTs) with those in comparable non-participants who received the same or similar treatment.

DATA SOURCES

Bibliographic databases, reference lists from eligible articles, medical journals, and study authors.

REVIEW METHODS

RCTs and cohort studies that evaluated the clinical outcomes of participants in RCTs and comparable non-participants who received the same or similar treatment.

RESULTS

Five RCTs (six comparisons) and 50 cohort studies (85 comparisons) provided data on 31,140 patients treated in RCTs and 20,380 comparable patients treated outside RCTs. In the five RCTs, in which patients were given the option of participating or not, the comparisons provided limited information because of small sample sizes (a total of 412 patients) and the nature of the questions considered. 73 dichotomous outcomes were compared, of which 59 reported no statistically significant differences. For patients treated within RCTs, 10 comparisons reported significantly better outcomes and four reported significantly worse outcomes. Significantly heterogeneity was found (I2 = 89%) among the comparisons of 73 dichotomous outcomes; none of our a priori explanatory factors helped explain this heterogeneity. The 18 comparisons of continuous outcomes showed no significant differences in heterogeneity (I2 = 0%). The overall pooled estimate for continuous outcomes of the effect of participating in an RCT was not significant (standardised mean difference 0.01, 95% confidence interval -0.10 to 0.12).

CONCLUSION

No strong evidence was found of a harmful or beneficial effect of participating in RCTs compared with receiving the same or similar treatment outside such trials.

n-of-1 randomized controlled trials: an opportunity for complementary and alternative medicine evaluation

Complementary and alternative medicine (CAM) practice has traditionally relied on expert opinion and case examples to evaluate the outcome of a particular therapeutic treatment. Such trials are subject to bias, leading to the formation of erroneous conclusions about the effectiveness of most treatments. This paper reviews the feasibility of n-of-1 trials to better evaluate the clinical and statistical significance of CAM therapies. In particular: (1) problems arising from the use of standard therapeutic trials; (2) the n-of-1 trial and data analysis; (3) clinical use and advantages of the n-of-1 trial in conventional medicine; (4) potential clinical uses of the n-of-1 trial in CAM; (5) preliminary guidelines for the use of the n-of-1 trial in CAM; (6) constraints on the use of the n-of-1 trial in CAM; and (7) ethical issues in the conduct of the n-of-1 trial.

Assessment of progression of COPD: report of a workshop held in Leuven, 11-12 March 2004

Recently performed long term trials have enhanced the insight into the assessment of progression of COPD. The present review focuses on the initial assessment of COPD in general practice and the assessment of disease progression. Several variables may be used to assess this progression, all of which are associated with significant methodological problems. Finding the appropriate mix of outcome measures to capture all aspects of disease progression is a significant challenge.

Evaluating health-promoting schools in Hong Kong: development of a framework

Health-promoting schools (HPS)/healthy schools have existed internationally for about 15 years. Yet there are few comprehensive evaluation frameworks available which enable the outcomes of HPS initiatives to be assessed. This paper identifies an evaluation framework developed in Hong Kong. The framework uses a range of approaches to explore what schools actually do in their health promotion and health education initiatives. The framework, which is based on the WHO (Western Pacific Regional Office) Guidelines for HPS, is described in detail. The appropriate instruments for data collection are described and their origins identified. The evaluation plan and protocol, which underpinned the very comprehensive evaluation in Hong Kong, are explained. Finally, a case is argued for evaluation of HPS to be more in line with the educational dynamics of schools and the research literature on effective schooling, rather than focusing primarily on health-related measures.

N-of-1 trials of quinine efficacy in skeletal muscle cramps of the leg

BACKGROUND

Skeletal muscle cramps affect over a third of the ambulatory elderly population. Quinine is the established treatment, but there are safety concerns, and evidence for efficacy is conflicting. A recent meta-analysis established a small advantage for quinine, but identified the need for additional studies. N-of-1 trials compare two treatments, in a randomised, double-blind, multiple crossover study on a patient-by-patient basis. They have been used to compare treatments in osteoarthritis and may be suitable for determining the individual efficacy of quinine.

AIM

To establish efficacy and safety of quinine sulphate use for the treatment of leg-muscle cramp.

DESIGN OF STUDY

Double-blind, randomised series of n-of-1 controlled trials of quinine versus placebo for muscle cramps.

SETTING

New Zealand general practices.

METHOD

The participants were 13 general practice patients (six males; seven females; median age = 75 years) already prescribed quinine. Following a 2-week washout, each patient received three 4-week treatment blocks of quinine sulphate and matched placebo capsules with an individual, randomised crossover design. The main outcome measures were: patient diaries of cramp occurrence, duration and severity; capsule counts; and blood quinine levels in the final treatment block.

RESULTS

Ten patients completed the trial. Three patients were identified for whom quinine was clearly beneficial (P <0.05), six showed non-significant benefit and one showed no benefit. All patients elected to continue quinine post-study.

CONCLUSION

Series of n -of-1 studies differentiated patients whom quinine had statistically significant effects; those with trend towards effectiveness; those for whom quinine was probably not effective. Ideally n-of-1 trial should be performed when a patient is commenced on quinine. More cycles in n-of-1 studies of quinine may address issues of statistical power.

Customization of Pain Treatments

The aim of this paper is to acquaint pain researchers and practitioners with recent developments in the single-case experimental approach and their potential to allow for tailoring the treatment and its evaluation to the specific complaints, aptitudes, or profile of the individual patient, without violating the canons of good science and practice. After contrasting the single-case experimental approach and the case-study approach, we show the possibilities of customization in design, measurement, and test statistics. This is done by distinguishing 2 types of single-case designs--alternation designs and phase designs--and 2 types of replication strategies--simultaneous replications and sequential replications. In addition, tailor-made randomization tests are proposed for alternation, phase, and simultaneous replication designs and the combining of P values to perform a meta-analysis on designs that are sequentially replicated. With our emphasis on: 1) randomization in the design; 2) the possibilities for a statistical test (together with the determination of power and the calculation of effect sizes); 3) the importance of reliable and valid measurement; and 4) the role of replication, we demonstrate how internal validity, statistical-conclusion validity, construct validity, and external validity concerns can be dealt with within a single-case experimental approach framework. Finally, the many research examples and references to clinical work illustrate the usefulness of the approach.

Single patient (n-of-1) trials with binary treatment preference

The use of a fully parametric Bayesian method for analysing single patient trials based on the notion of treatment 'preference' is described. This Bayesian hierarchical modelling approach allows for full parameter uncertainty, use of prior information and the modelling of individual and patient sub-group structures. It provides updated probabilistic results for individual patients, and groups of patients with the same medical condition, as they are sequentially enrolled into individualized trials using the same medication alternatives. Two clinically interpretable criteria for determining a patient's response are detailed and illustrated using data from a previously published paper under two different prior information scenarios.

Using Patients As Their Own Controls for Cost Evaluation of Phase I Clinical Trials

Purpose

Little is known about the cost of phase I trials in cancer patients compared with that of standard treatments, yet the former is often assumed to be greater than the latter. Our objective was to utilize a new approach, using patients as their own controls, to compare in a pilot study the costs of care for patients on phase I trials with those incurred for standard treatment.

Patients and Methods

We retrospectively assessed the direct medical costs (DMCs) of 59 patients participating in one of two phase I trials (TRIAL) in solid tumors conducted at Memorial Hospital (MH): (1) perillyl alcohol, and (2) flavopiridol with paclitaxel. Paired-control DMCs were those accrued by the same patient while receiving standard chemotherapy regimens just before (PRE; n = 41) or after (POST; n = 29) the trial at MH, averaged per day.

Results

For the 41 PRE patients, the median and mean DMCs per day for the clinical trial versus standard treatment were (US $) $123 v $133 and $219 v $267, respectively. For the 29 POST patients, the median and mean DMCs for the clinical trial versus standard treatment were $157 v $152 and $226 v $226, respectively. Using a linear mixed model, there was no significant difference between TRIAL and standard treatment DMCs (P = .54).

Conclusion

Using patients as their own controls represents a new, efficient method for evaluating the cost of phase I trials, and it warrants further study. The results of our pilot study do not suggest that phase I trials always cost payers more than standard treatment.

What is evidence-based medicine?

Evidence-based practice requires clinical expertise, common sense, understanding of the circumstances and values of the patient, and judicious application of the best available evidence. This article discusses evidence-based medicine as an explicit and formal problem-solving strategy.

Determination of the clinical importance of study results

Formal statistical methods for analyzing clinical trial data are widely accepted by the medical community. Unfortunately, the interpretation and reporting of trial results from the perspective of clinical importance has not received similar emphasis. This imbalance promotes the historical tendency to consider clinical trial results that are statistically significant as also clinically important, and conversely, those with statistically insignificant results as being clinically unimportant. In this paper, we review the present state of knowledge in the determination of the clinical importance of study results. This work also provides a simple, systematic method for determining the clinical importance of study results. It uses the relationship between the point estimate of the treatment effect (with its associated confidence interval) and the estimate of the smallest treatment effect that would lead to a change in a patient's management. The possible benefits of this approach include enabling clinicians to more easily interpret the results of clinical trials from a clinical perspective, and promoting a more rational approach to the design of prospective clinical trials.

Review article: Single subject trials as a research instrument in gastrointestinal pharmacology

The single subject trial is a randomized controlled trial carried out in the individual patient, and the result obtained is specific to the individual patient and the drug being investigated. This type of trial offers a supplement to traditional parallel group trials, especially in patients with heterogeneous disorders, often characterized by varying treatment responses and/or high placebo response rates. Pooled results from several individual single subject trials could extend the conclusions beyond the individual patient, and help to characterize a subset of responders to a specific treatment or clarify the heterogeneity of the disease. The basic principles of the different single subject trial designs are described. Advantages and limitations are reviewed with a special focus on published trials in functional gastrointestinal disorders. The single subject trial may be a valuable supplement to traditional drug treatment trials, either used as isolated trials in individual patients to determine optimal therapy, or in groups of patients to identify those with a uniform response to treatment. However, the lack of validation and reliability studies limits the value of the single subject trials presented so far.

Toward individualized evidence-based medicine: five "N of 1" trials of methylphenidate in geriatric patients

OBJECTIVES

To investigate the efficacy of methylphenidate in depressed or apathetic geriatric patients.

DESIGN

Five "N of 1" trials (individual cross-over, double-blinded, randomized trials).

SETTING

Department of Geriatrics, University Medical Center, Nijmegen, and two nursing homes in Nijmegen, the Netherlands.

PARTICIPANTS

Patients suffered from depression due to a general medical condition (n = 2); depression resistant to antidepressive drugs (n = 1), chronic apathy due to mild and moderate severe dementia (n = 2).

INTERVENTION

Methylphenidate (5 mg bid) and placebo (both for two subsequent days) in 5 weeks of randomized treatment blocks.

MEASUREMENTS

Montgomery Asberg Depression Rating Scale (MADRS), Apathy Evaluation Scale (AES)-clinician, the AES-informant, Barthel index and a semiquantitative checklist of adverse effects.

RESULTS

Among the three depressed patients, two showed significant improvement on the MADRS (P = .089 and P = .001; alpha = 0.10), one patient's apathy showed significant improvement on AES-clinician and -informant (P = .077 and P = .086). One apathetic patient's trial was stopped because AES could not be completed. None of the patients showed significant changes in the Barthel index. No side effects developed.

CONCLUSION

"N of 1" trials are useful in evaluating efficacy of methylphenidate in depressed or apathetic geriatric patients. Single-patient trials can be a useful tool in pharmacotherapeutic decision-making in frail older subjects.

Are randomized clinical trials good for us (in the short term)? Evidence for a "trial effect"

OBJECTIVE

To assess whether there is evidence that randomized controlled trials are systematically beneficial, or harmful, for patients. In other words, is there a "trial effect"? If so, to examine whether the evidence sheds light on the likely sources of the difference in outcomes.

METHODS

Systematic review of the literature.

RESULTS

We set out in some detail potential sources of a "trial effect" and potential biases. We found only 14 research articles (covering more than 21 trials) with relevant primary data. We extracted, with difficulty, quantitative data-sets from the articles, and classified these according to likely source of any apparent trial effect. The categories used were: differences in prognosis; superior treatment in the trial; and "protocol/Hawthorne effect" (benefit from improved routine care within a trial).

ANALYSIS

The evidence available is limited in breadth (coming largely from cancer trials) and quality, as well as quantity. There is weak evidence to suggest that clinical trials have a positive effect on the outcome of participants. This does not appear to depend strongly on the trial demonstrating that an experimental treatment is superior. However, benefit to participants is less evident where scope for a "protocol/Hawthorne effect" was apparently limited (because there was no effective routine treatment or because the comparison group also received protocol care). A form of bias, arising if clinicians who tend to recruit to trials also tend to be better clinicians, could also explain these results.

CONCLUSION

While the evidence is not conclusive, it is more likely that clinical trials have a positive rather than a negative effect on the outcome of patients. In the limited data available, the effect seems to be larger in trials where an effective treatment already exists and is included in the trial protocol.

RECOMMENDATION

That carefully researched treatment protocols, and monitoring of outcomes, be used for all patients, not just those in trials.

Preliminary experiences with a single-patient trials service in general practice

OBJECTIVE

To pilot a single-patient trials (SPTs) service in general practice, designed to improve decision-making about long-term medications for chronic conditions.

DESIGN

12-week within-patient, randomised, double-blind, placebo-controlled, crossover comparison of ibuprofen with paracetamol for osteoarthritis, involving three pairs of two-week treatment periods for each participating patient.

SETTING AND PATIENTS

Patients attending an academic general practice with a clinical diagnosis of osteoarthritis, with pain of at least a month's duration severe enough to warrant consideration of long-term non-steroidal anti-inflammatory drug (NSAID) use.

MAIN OUTCOME MEASURES

Pain and stiffness; measures of overall arthritis compared with previous fortnight; preference for NSAID at the end of each two-week treatment period; use of escape analgesia; side effects; and management changes as a result of the SPTs.

RESULTS

Eight of 14 patients completed SPTs. One was a clear responder to NSAIDs, five were non-responders, and two were indefinite. Of the five who were using NSAIDs' before the SPT, two continued and three ceased using them. Clinically useful information assisted decision-making for all eight participants. Medication management changed for six.

CONCLUSIONS

Single-patient trials can be successfully implemented in general practice and might be a valuable method for GPs to identify patients who respond to medication for chronic stable conditions such as osteoarthritis, in which individual response to medication is variable.

Guidelines in pulmonary medicine: a 25-year profile

OBJECTIVE

We attempted to identify clinical practice guideline and pathway articles in the area of pulmonary medicine published in peer-reviewed journals since 1974.

DESIGN

Review.

DATA SOURCES

MEDLINE, the Cochrane Database, Best Evidence, and Abstracts of Clinical Care Guidelines from January 1974 to December 1998.

STUDY SELECTION

All articles contained relevant search terms for pulmonary topics and were included irrespective of setting (primary or specialty, inpatient or outpatient). Controlled and uncontrolled trials as well as observational studies and consensus opinion/statements were all identified. The articles were stratified by design as well as by pulmonary topic.

DATA EXTRACTION

Limited data on study type, study focus, year of publication, and results of study were abstracted.

RESULTS

Our criteria yielded 271 articles, including 115 consensus statements and expert opinion guidelines; 30 controlled studies, meta-analyses, or systematic reviews; and 126 uncontrolled trials and observational studies. Of these, 82 articles (30.3%) related to asthma, 46 articles (17.0%) related to COPD, and 36 articles (13.3%) related to pneumonia. In addition, we tracked the increasing publication of all guideline-related pulmonary articles; randomized, controlled trials (RCTs); systematic reviews; and consensus statements by year for the past 25 years.

CONCLUSION

Pulmonary guidelines are increasingly published in peer-reviewed journals, but few are tested clinically in RCTs. There is continued reliance on consensus statements and expert opinion. Pulmonary guideline publications have continued to dramatically increase in number and in importance since 1974, both on the local level and internationally.

Theophylline for irreversible chronic airflow limitation: a randomized study comparing n of 1 trials to standard practice

STUDY OBJECTIVE

To compare quality of life and exercise capacity (primary aim), and drug usage (secondary aim), between groups of patients with irreversible chronic airflow limitation (CAL) who were undergoing theophylline Theo-Dur; Key Pharmaceuticals; Kenilworth, NJ) therapy guided by n of 1 trials or standard practice.

DESIGN

Randomized study of n of 1 trials vs standard practice.

SETTING

Outpatient departments in two tertiary care centers.

PATIENTS

Sixty-eight patients with irreversible CAL who were symptomatic despite the use of inhaled bronchodilators, and who were unsure whether theophylline was helping them following open treatment, were randomized into n of 1 trials (N=34) or standard practice.

INTERVENTIONS

The n of 1 trials (single-patient, randomized, double-blind, multiple crossover comparisons of the effect on dyspnea of theophylline vs a placebo) followed published guidelines. Standard practice patients stopped taking theophylline but resumed it if their dyspnea worsened. If their dyspnea then improved, theophylline was continued. In both groups, a decision about continuing or stopping the use of theophylline was made within 3 months of randomization.

MEASUREMENTS AND RESULTS

The primary outcomes (the chronic respiratory disease questionnaire [CRQ] and 6-min walk) were measured at baseline, 6 months, and 12 months by personnel blinded to treatment group allocation. No between-group differences (n of 1 minus standard practice) were seen in within-group changes over time (1 year minus baseline) in the CRQ Physical Function score (point estimate on the difference, -2.8; 95% confidence limits [CLs], -8.2, 2.5), CRQ Emotional Function score (point estimate on the difference, 0.5; 95% CLs, -4.7, 5.7), or 6-min walk (point estimate on the difference, 8 m; 95% CLs, -26, 44 m). No differences between groups were seen in the secondary outcome of the proportion of patients taking theophylline at 6 and 12 months. In 7 of 34 n of 1 trial patients (21%), dyspnea improved during theophylline treatment compared with placebo treatment.

CONCLUSIONS

Using n of 1 trials to guide theophylline therapy in patients with irreversible CAL did not improve their quality of life or exercise capacity, or reduce drug usa e, over 1 year compared to standard practice. Under the objective conditions of an n of 1 trial, 21% of patients with CAL responded to theophylline. There remains a rationale for considering theophylline in patients with irreversible CAL who remain symptomatic despite the use of inhaled bronchodilators, but the use of n of 1 trials to guide this decision did not yield clinically important advantages over standard practice.