Estimating causal effects from epidemiological data

In ideal randomised experiments, association is causation: association measures can be interpreted as effect measures because randomisation ensures that the exposed and the unexposed are exchangeable. On the other hand, in observational studies, association is not generally causation: association measures cannot be interpreted as effect measures because the exposed and the unexposed are not generally exchangeable. However, observational research is often the only alternative for causal inference. This article reviews a condition that permits the estimation of causal effects from observational data, and two methods -- standardisation and inverse probability weighting -- to estimate population causal effects under that condition. For simplicity, the main description is restricted to dichotomous variables and assumes that no random error attributable to sampling variability exists. The appendix provides a generalisation of inverse probability weighting.

Describing randomisation: patients' and the public's preferences compared with clinicians' practice

Explaining the concept of randomisation in simple terms to patients during the discussion of randomised clinical trials can be a difficult task for many health care professionals. We report the results of a questionnaire-based survey, using seven descriptions of randomisation taken from Corbett's study. We examined the preferences of the general public and patients towards the descriptions and compared the results with the clinicians' choice. Participants in the survey were 341 lay people without cancer, 200 patients with cancer and 200 oncologists from cancer centres throughout the UK. It was difficult to identify 'the best' way to describe the process of randomisation. The two most favoured statements for patients and members of the public included a very explicit statement that mentioned 'a computer', 'chance' and 'not the doctor's or patient's decision' and a succinct statement that played down the role of 'chance'. Clinicians chose neither of these statements as closely resembling their own practice. Patients and members of the public most disliked the statement 'a computer will perform the equivalent of tossing a coin to allocate you to one of two methods of treatment'. This analogy used by 26% of oncologists, was viewed as trivialising and upsetting in the context of determining treatment for life threatening disease.

Why do patients decline surgical trials? Findings from a qualitative interview study embedded in the Cancer Research UK BOLERO trial (Bladder cancer: Open versus Lapararoscopic or RObotic cystectomy)

BACKGROUND

Surgical trials have typically experienced recruitment difficulties when compared with other types of oncology trials. Qualitative studies have an important role to play in exploring reasons for low recruitment, although to date few such studies have been carried out that are embedded in surgical trials. The BOLERO trial (Bladder cancer: Open versus Lapararoscopic or RObotic cystectomy) is a study to determine the feasibility of randomisation to open versus laparoscopic access/robotic cystectomy in patients with bladder cancer. We describe the results of a qualitative study embedded within the clinical trial that explored why patients decline randomisation.

METHODS

Ten semi-structured interviews with patients who declined randomisation to the clinical trial, and two interviews with recruiting research nurses were conducted. Data were analysed for key themes.

RESULTS

The majority of patients declined the trial because they had preferences for a particular treatment arm, and in usual practice could choose which surgical method they would be given. In most cases the robotic option was preferred. Patients described an intuitive 'sense' that favoured the new technology and had carried out their own inquiries, including Internet research and talking with previous patients and friends and family with medical backgrounds. Medical histories and lifestyle considerations also shaped these personalised choices. Of importance too, however, were the messages patients perceived from their clinical encounters. Whilst some patients felt their surgeon favoured the robotic option, others interpreted 'indirect' cues such as the 'established' reputation of the surgeon and surgical method and comments made during clinical assessments. Many patients expressed a wish for greater direction from their surgeon when making these decisions.

CONCLUSION

For trials where the 'new technology' is available to patients, there will likely be difficulties with recruitment. Greater attention could be paid to how messages about treatment options and the trial are conveyed across the whole clinical setting. However, if it is too difficult to challenge such messages, then questions should be asked about whether genuine and convincing equipoise can be presented and perceived in such trials. This calls for consideration of whether alternative methods of generating evidence could be used when evaluating surgical techniques which are established and routinely available.

TRIAL REGISTRATION

TRIAL REGISTRATION NUMBER

ISRCTN38528926 (11 December 2008).

Are pilot trials useful for predicting randomisation and attrition rates in definitive studies: A review of publicly funded trials

BACKGROUND/AIMS

External pilot trials are recommended for testing the feasibility of main or confirmatory trials. However, there is little evidence that progress in external pilot trials actually predicts randomisation and attrition rates in the main trial. To assess the use of external pilot trials in trial design, we compared randomisation and attrition rates in publicly funded randomised controlled trials with rates in their pilots.

METHODS

Randomised controlled trials for which there was an external pilot trial were identified from reports published between 2004 and 2013 in the Health Technology Assessment Journal. Data were extracted from published papers, protocols and reports. Bland-Altman plots and descriptive statistics were used to investigate the agreement of randomisation and attrition rates between the full and external pilot trials.

RESULTS

Of 561 reports, 41 were randomised controlled trials with pilot trials and 16 met criteria for a pilot trial with sufficient data. Mean attrition and randomisation rates were 21.1% and 50.4%, respectively, in the pilot trials and 16.8% and 65.2% in the main. There was minimal bias in the pilot trial when predicting the main trial attrition and randomisation rate. However, the variation was large: the mean difference in the attrition rate between the pilot and main trial was -4.4% with limits of agreement of -37.1% to 28.2%. Limits of agreement for randomisation rates were -47.8% to 77.5%.

CONCLUSION

Results from external pilot trials to estimate randomisation and attrition rates should be used with caution as comparison of the difference in the rates between pilots and their associated full trial demonstrates high variability. We suggest using internal pilot trials wherever appropriate.

Methodology for research I

The conduct of research requires a systematic approach involving diligent planning and its execution as planned. It comprises various essential predefined components such as aims, population, conduct/technique, outcome and statistical considerations. These need to be objective, reliable and in a repeatable format. Hence, the understanding of the basic aspects of methodology is essential for any researcher. This is a narrative review and focuses on various aspects of the methodology for conduct of a clinical research. The relevant keywords were used for literature search from various databases and from bibliographies of the articles.

Informative value of Patient Reported Outcomes (PRO) in Health Technology Assessment (HTA)

Background

“Patient-Reported Outcome” (PRO) is used as an umbrella term for different concepts for measuring subjectively perceived health status e. g. as treatment effects. Their common characteristic is, that the appraisal of the health status is reported by the patient himself. In order to describe the informative value of PRO in Health Technology Assessment (HTA) first an overview of concepts, classifications and methods of measurement is given. The overview is complemented by an empirical analysis of clinical trials and HTA-reports on rheumatoid arthritis and breast cancer in order to report on type, frequency and consequences of PRO used in these documents.

Methods

For both issues systematic reviews of the literature have been performed. The search for methodological literature covers the publication period from 1990 to 2009, the search for clinical trials of rheumatoid arthritis and breast cancer covers the period 2005 to 2009. Both searches were performed in the medical databases of the German Institute of Medical Documentation and Information (DIMDI). The search for HTA-reports and methodological papers of HTA-agencies was performed in the CRD-Databases (CRD = Centre for Reviews and Dissemination) and by handsearching the websites of INAHTA member agencies (INAHTA = International Network of Agencies for Health Technology Assessment). For all issues specific inclusion and exclusion criteria were defined. The methodological quality of randomized controlled trials (RCT) was assessed by a modified version of the Cochrane Risk of Bias Tool. For the methodological part information extraction from the literature is structured by the report’s chapters, for the empirical part data extraction sheets were constructed. All information is summarized in a qualitative manner.

Results

Concerning the methodological issues the literature search retrieved 158 documents (87 documents related to definition or classification, 125 documents related to operationalisation of PRO). For the empirical analyses 225 RCT (rheumatoid arthritis: 77; breast cancer: 148) and 40 HTA-reports and method papers were found.

The analysis of the methodological literature confirms the role of PRO as an umbrella term for a variety of different concepts. The newest classification system facilitates the description of PRO measures by construct, target population and the method of measurement. Steps of operationalisation involve defining a conceptual framework, instrument development, exploration of measurement properties or, possibly, the modification of existing instruments.

Seven out of 59 RCT analysing the effects of antibody therapy for rheumatoid arthritis define PRO as the primary endpoint, 38 trials utilize composite measures (ACR, DAS) and ten trials report clinical or radiological parameters as the primary endpoint. Six out of 123 chemotherapy trials for breast cancer define PRO as the primary endpoint, while 98 trials report clinical endpoints (survival, tumour response, progression) in their primary analyses. Discrepancies in the number of trials result from inaccurate specifications of endpoints in the publications. This distribution is reflected in the HTA-reports: while almost all reports on rheumatoid arthritis refer to PRO, this is only the case in about half of the reports on breast cancer.

Conclusions

As definition and classification of PRO are concerned, coherent concepts are found in the literature. Their operationalisation and implementation must be guided by scientific principles. The type and frequency of PRO used in clinical trials largely depend on the disease analysed. The HTA-community seems to pursue the utilization of PRO proactively – in case of missing data the need for further research is stated.

Randomised P-values and nonparametric procedures in multiple testing

The validity of many multiple hypothesis testing procedures for false discovery rate (FDR) control relies on the assumption that P-value statistics are uniformly distributed under the null hypotheses. However, this assumption fails if the test statistics have discrete distributions or if the distributional model for the observables is misspecified. A stochastic process framework is introduced that, with the aid of a uniform variate, admits P-value statistics to satisfy the uniformity condition even when test statistics have discrete distributions. This allows nonparametric tests to be used to generate P-value statistics satisfying the uniformity condition. The resulting multiple testing procedures are therefore endowed with robustness properties. Simulation studies suggest that nonparametric randomised test P-values allow for these FDR methods to perform better when the model for the observables is nonparametric or misspecified.

Clinical trial design in chronic obstructive pulmonary disease: current perspectives and considerations with regard to blinding of tiotropium

Randomised, double-blind, controlled trials are considered the gold standard for evaluating a pharmacological agent, as they minimise any potential bias. However, it is not always possible to perform double-blind trials, particularly for medications delivered via specific devices, e.g. inhalers. In such cases, open-label studies can be employed instead. Methods used to minimise any potential bias introduced by open-label study design include randomisation, crossover study design, and objective measurements of primary efficacy and safety variables. Concise reviews analysing the effect of blinding procedures of comparator drugs on outcomes in respiratory trials are limited. Here, we compare data from different chronic obstructive pulmonary disease trials with once-daily indacaterol versus a blinded or non-blinded comparator. The clinical trial programme for indacaterol, a once-daily, long-acting β2-agonist, used tiotropium as a comparator either in an open-label or blinded fashion. Data from these studies showed that the effects of tiotropium were consistent for forced expiratory volume in 1 second, an objective measure, across blinded and non-blinded studies. The data were consistent with previous studies of double-blind tiotropium, suggesting that the open-label use of tiotropium did not introduce treatment bias. The effect of tiotropium on subjective measures (St George's Respiratory Questionnaire; transition dyspnoea index) varied slightly across blinded and non-blinded studies, indicating that minimal bias was introduced by using open-label tiotropium. Importantly, the studies used randomised, open-label tiotropium patients to treatment allocation, a method shown to minimise bias to a greater degree than blinding. In conclusion, it is important when reporting a clinical trial to be transparent about who was blinded and how the blinding was performed; if the design is open-label, additional efforts must be made to minimise risk of bias. If these recommendations are followed, and the data are considered in the full knowledge of any potential sources of bias, results with tiotropium suggest that data from open-label studies can provide valuable and credible evidence of the effects of therapy.

What is Scientific Research and How Can it be Done?

Scientific researches are studies that should be systematically planned before performing them. In this review, classification and description of scientific studies, planning stage randomisation and bias are explained.

Feasibility study of a randomised controlled trial to compare (deferred) androgen deprivation therapy and cryotherapy in men with localised radiation-recurrent prostate cancer

BACKGROUND

Salvage therapeutic options for biochemical failure after primary radiation-based therapy include radical prostatectomy, cryoablation, high-intensity focused ultrasound (HIFU), brachytherapy (for post-EBRT patients) and androgen deprivation therapy (ADT). ADT and salvage prostate cryoablation (SPC) are two commonly considered treatment options for RRPC. However, there is an urgent need for high-quality clinical studies to support evidence-based decisions on treatment choice. Our study aims to determine the feasibility of randomising men with RRPC for treatment with ADT and SPC.

METHODS

The randomised controlled trial (CROP) was developed, which incorporated protocols to assess parameters relating to cryotherapy procedures and provide training workshops for optimising patient recruitment. Analysis of data from the recruitment phase and patient questionnaires was performed.

RESULTS

Over a period of 18 months, 39 patients were screened for eligibility. Overall 28 patients were offered entry into the trial, but only 7 agreed to randomisation. The majority reason for declining entry into the trial was an unwillingness to be randomised into the study. 'Having the chance of getting cryotherapy' was the major reason for accepting the trial. Despite difficulty in retrieving cryotherapy temperature parameters from prior cases, 9 of 11 cryotherapy centres progressed through the Cryotherapists Qualification Process (CQP) and were approved for recruiting into the CROP study.

CONCLUSIONS

Conveying equipoise between the two study arms for a salvage therapy was challenging. The use of delayed androgen therapy may have been seen as an inferior option. Future cohort studies into available salvage options (including prostate cryotherapy) for RRPC may be more acceptable to patients than randomisation within an RCT.

Neck-specific training with a cognitive behavioural approach compared with prescribed physical activity in patients with cervical radiculopathy: a protocol of a prospective randomised clinical trial

BACKGROUND

Patients with cervical radiculopathy often have neck- and arm pain, neurological changes, activity limitations and difficulties in returning to work. Most patients are not candidates for surgery but are often treated with different conservative approaches and may be sick-listed for long periods. The purpose of the current study is to compare the effectiveness of neck-specific training versus prescribed physical activity.

METHODS/DESIGN

The current protocol is a two armed intervention randomised clinical trial comparing the outcomes of patients receiving neck specific training or prescribed physical activity. A total of 144 patients with cervical radiculopathy will be randomly allocated to either of the two interventions. The interventions will be delivered by experienced physiotherapists and last 14 weeks. The primary outcome variable is neck- and arm pain intensity measured with a Visual Analogue Scale accompanied with secondary outcome measures of impairments and subjective health measurements collected before intervention and at 3, 6, 12 and 24 months after base-line assessment.

DISCUSSION

We anticipate that the results of this study will provide evidence to support recommendations as to the effectiveness of conservative interventions for patients with cervical radiculopathy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01831271.

Placebo-controlled clinical trials: how trial documents justify the use of randomisation and placebo

BACKGROUND

Randomised clinical trials (RCTs) involve procedures such as randomisation, blinding, and placebo use, which are not part of standard medical care. Patients asked to participate in RCTs often experience difficulties in understanding the meaning of these and their justification.

METHODS

We reviewed RCT protocols, statements of the principal investigator (PI), and participant-information materials, as submitted for opinion to a research ethics committee. We evaluated how the justification for the use of placebo was described in these documents and how the participants had been informed about randomisation, placebo use, and the possible risks of receiving placebo.

RESULTS

In total, 52 RCTs were identified. Eighteen of the study protocols (35%) provided some rationale for the use of placebo. In 15 (29%) of the statements, the PI had provided justification for its use. Possible risks related to placebo use were described in nine (17%) of the statements. An explanation as to why placebo was necessary featured in only 12 (23%) of the sets of participant-information materials, and only six (12%) of the documents discussed the possible risks associated with placebo.

CONCLUSIONS

The justification of placebo control was inadequately described in the RCT study protocols, by principal or national co-ordinating investigators, and in participant-information documents. Furthermore, possible health-related risks associated with the use of placebo were poorly explained in the participant-information documents. Ethics committes and study participants need to be better informed of the rationale for the use of placebo, along with the associated risks.

Over-, under- and misuse of pain treatment in Germany

BACKGROUND

The HTA-report (Health Technology Assessment) deals with over- and undertreatment of pain therapy. Especially in Germany chronic pain is a common reason for the loss of working hours and early retirement. In addition to a reduction in quality of life for the affected persons, chronic pain is therefore also an enormous economic burden for society.

OBJECTIVES

Which diseases are in particular relevant regarding pain therapy?What is the social-medical care situation regarding pain facilities in Germany?What is the social-medical care situation in pain therapy when comparing on international level?Which effects, costs or cost-effects can be seen on the micro-, meso- and macro level with regard to pain therapy?Among which social-medical services in pain therapy is there is an over- or undertreatment with regard to the micro-, meso- and macro level?Which medical and organisational aspects that have an effect on the costs and/or cost-effectiveness have to be particularly taken into account with regard to pain treatment/chronic pain?What is the influence of the individual patient's needs (micro level) in different situations of pain (e. g. palliative situation) on the meso- and macro level?Which social-medical and ethical aspects for an adequate treatment of chronic pain on each level have to be specially taken into account?Is the consideration of these aspects appropriate to avoid over- or undertreatment?Are juridical questions included in every day care of chronic pain patients, mainly in palliative care?On which level can appropriate interventions prevent over- or undertreatment?

METHODS

A systematic literature research is done in 35 databases. In the HTA, reviews, epidemiological and clinical studies and economic evaluations are included which report about pain therapy and in particular palliative care in the years 2005 till 2010.

RESULTS

47 studies meet the inclusion criteria. An undertreatment of acupuncture, over- and misuse with regard to opiate prescription and an overuse regarding unspecific chest pain and chronic low back pain (LBP) can be observed. The results show the benefit and the cost-effectiveness of interdisciplinary as well as multi-professional approaches, multimodal pain therapy and cross-sectoral integrated medical care. Only rough values can be determined about the care situation regarding the supply of pain therapeutic and palliative medical facilities as the data are completely insufficient.

DISCUSSION

Due to the broad research question the HTA-report contains inevitably different outcomes and study designs which partially differ qualitatively very strong from each other. In the field of palliative care hospices for in-patients and palliative wards as well as hospices for out-patients are becoming more and more important. Palliative care is a basic right of all terminally ill persons.

CONCLUSION

Despite the relatively high number of studies in Germany the HTA-report shows a massive lack in health care research. Based on the studies a further expansion of out-patient pain and palliative care is recommended. Further training for all involved professional groups must be improved. An independent empirical analysis is necessary to determine over or undertreatment in pain care.

Effectiveness of programmes as part of primary prevention demonstrated on the example of cardiovascular diseases and the metabolic syndrome

Background

The HTA-report (HTA = Health Technology Assessment) deals with the primary prevention of cardiovascular diseases and diabetes mellitus type 2. In 2009 approximately 356,000 people died in Germany due to cardiovascular diseases. According to estimations about 6.3 million people are suffering from diabetes mellitus type 2. The interventions that are subsidized by the public health insurance are mainly focused on sufficient physical activities, healthy nutrition, stress management and the reduction of the consumption of addictive drugs and luxury food.

Objectives

Which lifestyle-related measures and/or programmes for primary prevention of cardiovascular diseases and of the metabolic syndrome are effective? To what extent will the health status be improved by these offers? To what extent will existing health resources and skills be strengthened by these offers? Are there any differences regarding the effectiveness among the interventions with respect to different settings or subgroups?

Which lifestyle-related interventions and/or programmes for primary prevention of cardiovascular diseases and of the metabolic syndrome are sustainable and cost-effective? Which outcome parameters are in the view of the contributors decisive for the evaluation of the effectiveness? In the view of the contributor are there different values between the outcome parameters? In the view of the payers and other actors are there different values between the outcome parameters?

Which ethical and juridical factors have to be considered? Which social and/or socio-economic parameters influence the use of the services and effectiveness?

Methods

A systematic literature research is done in 35 databases. For the period 2005 to 2010, reviews, epidemiological and clinical studies as well as economical evaluations which deal with primary prevention programmes regarding cardiovascular diseases or the metabolic syndrome are included.

Results

44 publications meet the inclusion criteria. These studies confirm the effectiveness of the primary prevention programmes. Physical activity programs seem to have a stronger effect than nutrition programmes. Psychological programmes prove as well effectiveness, if they include cognitive behaviour therapy. The identified economical studies indicate that programmes for cardiovascular prevention can be conducted cost-effectively. Interventions that focus on the general population turn out to be particularly cost-effective and sustainable.

Discussion

There is a wide range of primary preventive effective lifestyle-related interventions with high evidence. The outcomes and results are consistent with the recommendations of the two identified evidence-based guidelines regarding the recommendations on lifestyle and healthy nutrition. Furthermore, the cost-effectiveness of primary prevention services is proven. With regard to the economical studies it is however worth noting that this result is based on very few publications. The transferability has to be critically assessed as the studies mainly originate from the American health system.

Conclusion

On the whole a comprehensive setting approach with educative, somatic, psychosocial and activity therapeutic components is recommended. The sustainability of a prevention intervention must be ensured from programme to programme. Long-term studies are necessary to make valid statements regarding the sustainable effectiveness: There is an essential deficit in the current practiced evaluation of the use of primary prevention services provided by the health insurance – mainly regarding the comprehensive setting approach – regarding the evidence-based evaluation of the prescribed preventive interventions. With regard to the ethical, social and economical evaluation the research situation is deficient. The situation has to be particularly analyzed for the socially deprived and one has to respond to their specific needs for prevention.

"Losing the tombola": a case study describing the use of community consultation in designing the study protocol for a randomised controlled trial of a mental health intervention in two conflict-affected regions

BACKGROUND

Community consultation is increasingly recommended, and in some cases, required by ethical review boards for research that involves higher levels of ethical risk such as international research and research with vulnerable populations. In designing a randomised control trial of a mental health intervention using a wait list control, we consulted the community where the research would be undertaken prior to finalising the study protocol. The study sites were two conflict-affected locations: Grozny in the Chechen Republic and Kitchanga in eastern Democratic Republic of Congo.

METHODS

Group discussions with a range of community members were held in both study sites. Facilitators used a prepared set of questions to guide the discussions and to solicit feedback on the value of the research as well as on the study design. Specific questions were asked about enablers and barriers to participation in the research.

RESULTS

Six groups were held in Grozny and thirteen in Kitchanga. The majority of individuals and groups consulted supported the research, and understood the purpose. In Grozny, the main concern raised was the length of the waiting period. Barriers to both waiting and returning for follow up were identified. In Kitchanga, there was a strong reaction against the wait list control and against randomisation. The consultations provided information on unanticipated harms to the community, allowing changes to the study design to mitigate these harms and increase acceptability of the study. It also served to inform the community of the study, and through engaging with them early, helped promote legitimacy and joint responsibility.

CONCLUSION

Community consultation prior to finalising the study design for a mental health intervention trial in two humanitarian settings proved feasible. Our experience reinforces the importance of community consultation before the study design is finalised and the importance of broad consultation that includes both community leaders and the potential study participants.

Critical appraisal of published literature

With a large output of medical literature coming out every year, it is impossible for readers to read every article. Critical appraisal of scientific literature is an important skill to be mastered not only by academic medical professionals but also by those involved in clinical practice. Before incorporating changes into the management of their patients, a thorough evaluation of the current or published literature is an important step in clinical practice. It is necessary for assessing the published literature for its scientific validity and generalizability to the specific patient community and reader's work environment. Simple steps have been provided by Consolidated Standard for Reporting Trial statements, Scottish Intercollegiate Guidelines Network and several other resources which if implemented may help the reader to avoid reading flawed literature and prevent the incorporation of biased or untrustworthy information into our practice.

The effectiveness of interventions in workplace health promotion as to maintain the working capacity of health care personal

Background

The increasing proportion of elderly people with respective care requirements and within the total population stands against aging personnel and staff reduction in the field of health care where employees are exposed to high load factors. Health promotion interventions may be a possibility to improve work situations and behavior.

Methods

A systematic literature search is conducted in 32 databases limited to English and German publications since 1990. Moreover, internet-searches are performed and the reference lists of identified articles are scanned. The selection of literature was done by two reviewers independently according to inclusion and exclusion criteria. Data extraction and tables of evidence are verified by a second expert just like the assessment of risk of bias by means of the Cochrane Collaboration’s tool.

Results

We identified eleven intervention studies and two systematic reviews. There were three randomized controlled trials (RCT) and one controlled trial without randomization (CCT) on the improvement of physical health, four RCT and two CCT on the improvement of psychological health and one RCT on both. Study duration ranged from four weeks to two years and the number of participants included from 20 to 345, with a median of 56. Interventions and populations were predominantly heterogeneous. In three studies intervention for the improvement of physical health resulted in less complaints and increased strength and flexibility with statistically significant differences between groups. Regarding psychological health interventions lead to significantly decreased intake of analgesics, better stress management, coping with workload, communication skills and advanced training.

Discussion

Taking into consideration the small to very small sample sizes, other methodological flaws like a high potential of bias and poor quality of reporting the validity of the results has to be considered as limited. Due to the heterogeneity of health interventions, study populations with differing job specializations and different lengths of study durations and follow-up periods, the comparison of results would not make sense.

Conclusions

Further research is necessary with larger sample sizes, with a sufficient study duration and follow-up, with a lower risk of bias, by considering of relevant quality criteria and with better reporting in publications.

Weight loss, insulin resistance, and study design confound results in a meta-analysis of animal models of fatty liver

The classical drug development pipeline necessitates studies using animal models of human disease to gauge future efficacy in humans, however there is a low conversion rate from success in animals to humans. Non-alcoholic fatty liver disease (NAFLD) is a complex chronic disease without any established therapies and a major field of animal research. We performed a meta-analysis with meta-regression of 603 interventional rodent studies (10,364 animals) in NAFLD to assess which variables influenced treatment response. Weight loss and alleviation of insulin resistance were consistently associated with improvement in NAFLD. Multiple drug classes that do not affect weight in humans caused weight loss in animals. Other study design variables, such as age of animals and dietary composition, influenced the magnitude of treatment effect. Publication bias may have increased effect estimates by 37-79%. These findings help to explain the challenge of reproducibility and translation within the field of metabolism.

Bone graft substitutes for the treatment of traumatic fractures of the extremities

HEALTH POLITICAL AND SCIENTIFIC BACKGROUND: Bone graft substitutes are increasingly being used as supplements to standard care or as alternative to bone grafts in the treatment of traumatic fractures.

RESEARCH QUESTIONS

The efficacy and cost-effectiveness of bone graft substitutes for the treatment of traumatic fractures as well as the ethical, social and legal implications of their use are the main research questions addressed.

METHODS

A systematic literature search was conducted in electronic medical databases (MEDLINE, EMBASE etc.) in December 2009. Randomised controlled trials (RCT), where applicable also containing relevant health economic evaluations and publications addressing the ethical, social and legal aspects of using bone graft substitutes for fracture treatment were included in the analysis. After assessment of study quality the information synthesis of the medical data was performed using metaanalysis, the synthesis of the health economic data was performed descriptively.

RESULTS

14 RCT were included in the medical analysis, and two in the heath economic evaluation. No relevant publications on the ethical, social and legal implications of the bone graft substitute use were found. In the RCT on fracture treatment with bone morphogenetic protein-2 (BMP-2) versus standard care without bone grafting (RCT with an elevated high risk of bias) there was a significant difference in favour of BMP-2 for several outcome measures. The RCT of calcium phosphate (CaP) cement and bone marrow-based composite materials versus autogenous bone grafts (RCT with a high risk of bias) revealed significant differences in favour of bone graft substitutes for some outcome measures. Regarding the other bone graft substitutes, almost all comparisons demonstrated no significant difference. The use of BMP-2 in addition to standard care without bone grafting led in the study to increased treatment costs considering all patients with traumatic open fractures. However, cost savings through the additional use of BMP-2 were calculated in a patient subgroup with high-grade open fractures (Gustilo-Anderson grade IIIB). Cost-effectiveness for BMP-2 versus standard care with autologous bone grafts as well as for other bone graft substitutes in fracture treatment has not been determined yet.

DISCUSSION

Although there were some significant differences in favour of BMP-2, due to the overall poor quality of the studies the evidence can only be interpreted as suggestive for efficacy. In the case of CaP cements and bone marrow-based bone substitute materials, the evidence is only weakly suggestive for efficacy. From an overall economic perspective, the transferability of the results of the health economic evaluations to the current situation in Germany is limited.

CONCLUSIONS

The current evidence is insufficient to evaluate entirely the use of different bone graft substitutes for fracture treatment. From a medical point of view, BMP-2 is a viable alternative for treatment of open fractures of the tibia, especially in cases where bone grafting is not possible. Autologous bone grafting is preferable comparing to the use of OP-1. Possible advantages of CaP cements and composites containing bone marrow over autogenous bone grafting should be taken into account in clinical decision making. The use of the hydroxyapatite material and allograft bone chips compared to autologous bone grafts cannot be recommended. From a health economic perspective, the use of BMP-2 in addition to standard care without bone grafting is recommended as cost-saving in patients with high-grade open fractures (Gustilo-Anderson grade IIIB). Based on the current evidence no further recommendations can be made regarding the use of bone graft substitutes for the treatment of fractures. To avoid legal implications, use of bone graft substitutes outside their approved indications should be avoided.

Participant views on participating in a pragmatic randomised controlled trial: the Aboriginal and Torres Strait Islander Women's Fitness Program

INTRODUCTION

The inequity of randomising participants to control groups in randomised controlled trials (RCTs) is often considered inappropriate, especially for research trials that include vulnerable populations such as Indigenous peoples. The Aboriginal and Torres Strait Islander Women's Fitness Program conducted a trial that randomly assigned participants to 'active' and 'waitlisted' groups. This paper reports on participant views of the randomisation protocol.

METHODS

A pragmatic RCT was conducted in an urban setting to assess the effectiveness of the 12-week Aboriginal and Torres Strait Islander Women's Fitness Program on metabolic health outcomes and waist circumference. Qualitative interviews were conducted at follow-up, one of the objectives was to explore participant perspectives on the research protocol, including participant randomisation to 'Active' and 'Waitlisted' groups.

RESULTS

A total of 49 interviews were conducted (26 Active and 23 Waitlisted participants). Two key factors influenced participant views on the protocol: 1) group assignment; and 2) how well they understood the research design, including the justification for randomisation. 'Active' participants were concerned about the inequity of the randomisation process but overall supported the study protocol. Although most Waitlisted participants were disappointed about having to wait 12-months for the program, some participants derived motivation from being waitlisted, whilst others lost motivation. Well-informed participants were more likely to express both support for the randomisation process and an understanding of the research benefits than participants not attending an information session prior to registration.

CONCLUSIONS

Participants were more accepting of the research protocol if it was clearly explained to them, if they understood the randomisation process and felt the randomisation was justified in terms of the potential for the results to benefit other Aboriginal and Torres Strait Islander women. Our study suggests that the time and resources required to adequately explain the research protocol in research trials should not be undervalued.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12610000224022).

Prevention of alcohol misuse among children, youths and young adults

BACKGROUND

Despite many activities to prevent risky alcohol consumption among adolescents and young adults there is an increase of alcohol intoxications in the group of ten to twenty year old juveniles.

OBJECTIVES

This report gives an overview about the recent literature as well as the German federal prevention system regarding activities concerning behavioral and policy prevention of risky alcohol consumption among children, adolescents and young adults. Furthermore, effective components of prevention activities are identified and the efficiency and efficacy of ongoing prevention programs is evaluated.

METHODS

A systematic literature review is done in 34 databases using Bool'sche combinations of the key words alcohol, prevention, treatment, children, adolescents and young adults.

RESULTS

401 studies were found and 59 studies were selected for the health technology assessment (HTA). Most of the studies are done in USA, nine in Germany. A family strengthening program, personalized computer based intervention at schools, colleges and universities, brief motivational interventions and policy elements like increase of prices and taxes proved effective.

DISCUSSION

Among the 59 studies there are three meta-analyses, 15 reviews, 17 randomized controlled trials (RCT) and 18 cohort studies. Despite the overall high quality of the study design, many of them have methodological weaknesses (missing randomization, missing or too short follow-ups, not clearly defined measurement parameters). The transferability of US-results to the German context is problematic. Only a few prevention activities reach a sustainable reduction of frequency and/or amount of alcohol consumption.

CONCLUSION

The HTA-report shows the need to develop specific and target group focused prevention activities for the German situation. Essential for that is the definition of target goals (reduction of consumption, change of behaviour) as well as the definition and empirical validation of risky alcohol consumption. The efficacy of prevention activities should be proven before they are launched. At present activities for the reduction or prevention of risky alcohol consumption are not sufficiently evaluated in Germany concerning their sustainable efficacy.

Methodology Series Module 4: Clinical Trials

In a clinical trial, study participants are (usually) divided into two groups. One group is then given the intervention and the other group is not given the intervention (or may be given some existing standard of care). We compare the outcomes in these groups and assess the role of intervention. Some of the trial designs are (1) parallel study design, (2) cross-over design, (3) factorial design, and (4) withdrawal group design. The trials can also be classified according to the stage of the trial (Phase I, II, III, and IV) or the nature of the trial (efficacy vs. effectiveness trials, superiority vs. equivalence trials). Randomization is one of the procedures by which we allocate different interventions to the groups. It ensures that all the included participants have a specified probability of being allocated to either of the groups in the intervention study. If participants and the investigator know about the allocation of the intervention, then it is called an “open trial.” However, many of the trials are not open – they are blinded. Blinding is useful to minimize bias in clinical trials. The researcher should familiarize themselves with the CONSORT statement and the appropriate Clinical Trials Registry of India.

Too simple models may predict the island rule for the wrong reasons

Biddick & Burns (2021) proposed a null/neutral model that reproduces the island rule as a product of random drift. We agree that it is unnecessary to assume adaptive processes driving island dwarfing or gigantism, but several flaws make their approach unrealistic and thus unsuitable as a stochastic model for evolutionary size changes.

Highlights from the 2013 Science of Placebo thematic workshop

In the last 30 years, a converging series of laboratory experiments, clinical trials, and neurocognitive studies have identified several key mechanisms of placebo effects. These studies suggest not only that placebo responses may be ubiquitous across research and clinical settings, but also that they can significantly modulate symptoms across a wide spectrum of highly prevalent conditions such as acute pain, chronic pain, anxiety, depression, Parkinson’s disease, and nausea, just to name a few. In order to inform the medical community about the most recent advances in the field of placebo studies, a thematic workshop entitled “The Science of Placebo” was held at the Beth Israel Deaconesses Medical Center (BIDMC), Harvard Medical School, in Boston (MA), on the 19–20 of June 2013. The workshop, sponsored by The Robert Wood Johnson Foundation, was organised by the Program in Placebo Studies and the Therapeutic Encounter, a Harvard-wide network of researchers dedicated to the study of the placebo phenomenon hosted by the BIDMC. The event was structured as a series of four public lectures, each delivered by a leading investigator in the field of placebo studies. The four keynote speakers were Fabrizio Benedetti, professor of neurophysiology and human physiology at the University of Turin Medical School and at the National Institute of Neuroscience in Italy; Tor Wager, director of the Cognitive and Affective Control Laboratory and associate professor of psychology and neuroscience at the University of Colorado; Predrag Petrovic, psychiatrist and researcher in the Department of Clinical Neuroscience at the Karolinska Institute in Stockholm; and Ted Kaptchuk, director of the Program in Placebo Studies and associate professor of medicine at Harvard Medical School.

The Quality of Reporting Raises Questions on the Experimental Validity of Animal Studies Conducted in India and Sri Lanka: Preliminary Analysis of a Systematic Survey

The quality of animal experiments in terms of appropriate reporting is a concern, particularly with regard to their validity and the recording of the measures taken to reduce various types of bias. A systematic survey of 1371 and 236 publications from India and Sri Lanka, respectively, which were published between 1905 and 2017 and indexed in NCBI-PubMed, Cinhal, MEDLINE and Scopus, was carried out. The level of detail in the descriptions of animals used and the measures taken to reduce bias were analysed in each article. Selected parameters from the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines, such as age, weight, sex, sample size calculation, blinding and randomisation were considered. The findings revealed poor reporting standards in animal experiments carried out in India and Sri Lanka, confirming the limited impact of the ARRIVE guidelines. These findings emphasise the urgent need for improvements in the peer review process, both prior to a study being set up and in the post-study reporting phase, and for more stringent adherence to the ARRIVE guidelines in the reporting of animal experiments.