Medical Research Studies Research Articles

Sample size determination for multilevel hierarchical designs using generalized linear mixed models.

A unified statistical methodology of sample size determination is developed for hierarchical designs that are frequently used in many areas, particularly in medical and health research studies. The solid foundation of the proposed methodology opens a new horizon for power analysis in presence of various conditions. Important features such as joint significance testing, unequal allocations of clusters across intervention groups, and differential attrition rates over follow up time points are integrated to address some useful questions that investigators often encounter while conducting such studies. Proposed methodology is shown to perform well in terms of maintaining type I error rates and achieving the target power under various conditions. Proposed method is also shown to be robust with respect to violation of distributional assumptions of random-effects.

Complex CatSper-dependent and independent [Ca2+]i signalling in human spermatozoa induced by follicular fluid.

STUDY QUESTIONDoes progesterone in human follicular fluid (hFF) activate CatSper and do other components of hFF modulate this effect and/or contribute separately to hFF-induced Ca2+ signaling?SUMMARY ANSWERhFF potently stimulates CatSper and increases [Ca2+]i, primarily due to high concentrations of progesterone, however, other components of hFF also contribute to [Ca2+]i signaling, including modulation of CatSper channel activity and inhibition of [Ca2+]i oscillations.WHAT IS KNOWN ALREADYCatSper, the principal Ca2+ channel in spermatozoa, is progesterone-sensitive and essential for fertility. Both hFF and progesterone, which is present in hFF, influence sperm function and increase their [Ca2+]i.STUDY DESIGN, SIZE, DURATIONThis basic medical research study used semen samples from >40 donors and hFF from >50 patients who were undergoing surgical oocyte retrieval for IVF/ICSI.PARTICIPANTS/MATERIALS, SETTING, METHODSSemen donors and patients were recruited in accordance with local ethics approval (13/ES/0091) from the East of Scotland Research Ethics Service REC1. Activities of CatSper and KSper were assessed by patch clamp electrophysiology. Sperm [Ca2+]i responses were examined in sperm populations and single cells. Computer-assisted sperm analysis (CASA) parameters and penetration into viscous media were used to assess functional effects.MAIN RESULTS AND THE ROLE OF CHANCEhFF and progesterone significantly potentiated CatSper currents. Under quasi-physiological conditions, hFF (up to 50%) failed to alter membrane K+ conductance or current reversal potential. hFF and progesterone (at an equivalent concentration) stimulated similar biphasic [Ca2+]i signals both in sperm populations and single cells. At a high hFF concentration (10%), the sustained (plateau) component of the [Ca2+]i signal was consistently greater than that induced by progesterone alone. In single cell recordings, 1% hFF-induced [Ca2+]i oscillations similarly to progesterone but with 10% hFF generation of [Ca2+]i oscillations was suppressed. After treatment to ‘strip’ lipid-derived mediators, hFF failed to significantly stimulate CatSper currents but induced small [Ca2+]i responses that were greater than those induced by the equivalent concentration of progesterone after stripping. Similar [Ca2+]i responses were observed when sperm pretreated with 3 μM progesterone (to desensitize progesterone responses) were stimulated with hFF or stripped hFF. hFF stimulated viscous media penetration and was more effective than the equivalent does of progesterone.LARGE SCALE DATAN/A.LIMITATIONS, REASONS FOR CAUTIONThis was an in vitro study. Caution must be taken when extrapolating these results in vivo.WIDER IMPLICATIONS OF THE FINDINGSThis study directly demonstrates that hFF activates CatSper and establishes that the biologically important effects of hFF reflect, at least in part, action on this channel, primarily via progesterone. However, these experiments also demonstrate that other components of hFF both contribute to the [Ca2+]i signal and modulate the activation of CatSper. Simple in vitro experiments performed out of the context of the complex in vivo environment need to be interpreted with caution.STUDY FUNDING/COMPETING INTEREST(S)Funding was provided by MRC (MR/K013343/1, MR/012492/1) (S.G.B., S.J.P., C.L.R.B.) and University of Abertay (sabbatical for S.G.B.). Additional funding was provided by TENOVUS SCOTLAND (S.M.D.S.), Chief Scientist Office/NHS Research Scotland (S.M.D.S). C.L.R.B. is EIC of MHR and Chair of the WHO ESG on Diagnosis of Male infertility. The remaining authors have no conlicts of interest.

Preclinical AD and Biomarker; from J-ADNI to AMED Preclinical Study

Alzheimer's disease (AD) is most prevalent cause of dementia and no cure has been discovered. Although the framework of AD clinical trials is being established utilizing results of large-scale observational studies such as the AD Neuroimaging Initiative (ADNI) and the Japanese-ADNI (J-ADNI), the development of disease-modifying therapy for Alzheimer's disease (AD) has not yet been achieved. Preclinical AD was recently defined as a new disease stage in which AD is asymptomatic but biomarkers suggest the presence of amyloid pathology. Preclinical AD has been focused as promising therapeutic time window and establishment of reliable biomarkers for preclinical AD is an urgent task. The Japanese Agency for Medical Research and Development (AMED) preclinical study is a nationwide multicenter observational study carried out by public research funding from AMED as a successor to the J-ADNI study. The goal of this study is to establish a biomarker that can quantitatively evaluate the disease progression of preclinical AD and mild cognitive impairment (MCI) or predict the progression to MCI and dementia in the future. To achieve this goal, the following assessments will be conducted over time for three years: clinical evaluations; cognitive tests; genetic testing; body fluid biomarker tests; and imaging biomarker studies such as MRI, FDG-PET, and amyloid PET. The obtained data will eventually be released to the public database.

Statistical controversies in clinical research: overlap and errors in the meta-analyses of microRNA genetic association studies in cancers

Various errors in the design, conduct, and analysis of medical and public health research studies can produce false results and waste valuable resources. While systematic reviews and meta-analyses are arguably considered the most dependable source of evidence-based medicine, increasing numbers of studies are indicating that, on the contrary to the public's belief, many of these investigations are redundant, erroneous, and even biased. Ninety-four meta-analyses on microRNA polymorphism and risk of cancer were extracted from Pubmed database on August 2016. Two investigators independently extracted data (i.e. number of studies, ethnicity, number of cases/controls, bias, etc.) from each meta-analysis. PROSPERO registration status and reference status were also recorded. Among the 217 microRNA gene-variant cancer associations reported by 94 published meta-analyses, 37% had overlapping results and were extracted from the exact identical case-control studies. However, not one meta-analysis was registered into PROSPERO. Thirty-one percent of the overlapping associations referenced a previous meta-analysis investigating the same association; although only 36% of these overlapping associations referenced earlier meta-analysis that had the same overlapping results. Seventy-four percent of these references were limited to mere citations. Twenty-six percent of the overlapping associations from 16 meta-analyses showed discordant results, and of these, 87% of the genotype comparisons were found significant, contrary to the initial reports of being non-significant. However, no association was noteworthy in regards to false positive rate probability calculations at a given prior probability of 0.001 and 0.000001 and statistical power to detect an odds ratio (OR) of 1.1 and 1.5. Genetic association meta-analyses were by far more redundant, erroneous, and lacking references than initially expected. Careful search of similar studies, attention to small details, and inclination to reference previous works are needed. This paper proposes potential solutions for these problems in hopes of standardizing research efforts and in improving the quality of medical research.

Giving voice to African thought in medical research ethics.

In this article, I consider the virtual absence of an African voice and perspective in global discourses of medical research ethics against the backdrop of the high burden of diseases and epidemics on the continent and the fact that the continent is actually the scene of numerous and sundry medical research studies. I consider some reasons for this state of affairs as well as how the situation might be redressed. Using examples from the HIV/AIDS and Ebola epidemics, I attempt to show that the marginalization of Africa in medical research and medical research ethics is deliberate rather than accidental. It is causally related, in general terms, to a Eurocentric hegemony derived from colonialism and colonial indoctrination cum proselytization. I end by proposing seven theses for the critical reflection and appraisal of the reader.

A High Power, Frequency Tunable Colloidal Quantum Dot (CdSe/ZnS) Laser.

Tunable lasers are essential for medical, engineering and basic science research studies. Most conventional solid-state lasers are capable of producing a few million laser shots, but limited to specific wavelengths, which are bulky and very expensive. Dye lasers are continuously tunable, but exhibit very poor chemical stability. As new tunable, efficient lasers are always in demand, one such laser is designed with various sized CdSe/ZnS quantum dots. They were used as a colloid in tetrahydrofuran to produce a fluorescent broadband emission from 520 nm to 630 nm. The second (532 nm) and/or third harmonic (355 nm) of the Nd:YAG laser (10 ns, 10 Hz) were used together as the pump source. In this study, different sized quantum dots were independently optically pumped to produce amplified spontaneous emission (ASE) with 4 nm to 7 nm of full width at half-maximum (FWHM), when the pump power and focusing were carefully optimized. The beam was directional with a 7 mrad divergence. Subsequently, these quantum dots were combined together, and the solution was placed in a resonator cavity to obtain a laser with a spectral width of 1 nm and tunable from 510 to 630 nm, with a conversion efficiency of about 0.1%.

Indirect evidence of reporting biases was found in a survey of medical research studies

ObjectivesTo explore indirect evidence of reporting biases by examining the distribution of P-values reported in published medical articles and to compare P-values distributions across different contexts. Study Design and SettingWe selected a random sample (N = 1,500) of articles published in PubMed in March 2014. We extracted information on study type, design, medical discipline, and P-values for the first reported outcome and primary outcome (if specified) from each article. We plotted the P-values transformed to the z-score scale and used caliper tests to investigate threshold effects. ResultsOut of the 1,500 randomly selected records, 758 (50.5%) were included. We retrieved or calculated 758 P-values for first reported outcomes and 389 for primary outcomes (specified in only 51% of included studies). The first reported and the primary outcome differed in 28% (110/389) of the included studies. The distributions of P-values for first reported outcomes and primary outcomes showed a notable discontinuity at the common thresholds of statistical significance (P-value = 0.05 and P-value = 0.01). We also found marked discontinuities in the distributions of z-scores across various medical disciplines, study designs, and types. ConclusionReporting biases are still common in medical research. We discuss their implications, strategies to detect them, and recommended practices to avoid them.

The Use of Social Media in Recruitment for Medical Research Studies: A Scoping Review

BackgroundRecruiting an adequate number of participants into medical research studies is challenging for many researchers. Over the past 10 years, the use of social media websites has increased in the general population. Consequently, social media websites are a new, powerful method for recruiting participants into such studies.ObjectiveThe objective was to answer the following questions: (1) Is the use of social media more effective at research participant recruitment than traditional methods? (2) Does social media recruit a sample of research participants comparable to that recruited via other methods? (3) Is social media more cost-effective at research participant recruitment than traditional methods?MethodsUsing the MEDLINE, PsycINFO, and EMBASE databases, all medical research studies that used social media and at least one other method for recruitment were identified. These studies were then categorized as either interventional studies or observational studies. For each study, the effectiveness of recruitment, demographic characteristics of the participants, and cost-effectiveness of recruitment using social media were evaluated and compared with that of the other methods used. The social media sites used in recruitment were identified, and if a study stated that the target population was “difficult to reach” as identified by the authors of the study, this was noted.ResultsOut of 30 studies, 12 found social media to be the most effective recruitment method, 15 did not, and 3 found social media to be equally effective as another recruitment method. Of the 12 studies that found social media to be the best recruitment method, 8 were observational studies while 4 were interventional studies. Of the 15 studies that did not find social media to be the best recruitment method, 7 were interventional studies while 8 were observational studies. In total, 8 studies stated that the target population was “hard-to-reach,” and 6 of these studies found social media to be the most effective recruitment method. Out of 14 studies that reported demographic data for participants, 2 studies found that social media recruited a sample comparable to that recruited via traditional methods and 12 did not. Out of 13 studies that reported cost-effectiveness, 5 studies found social media to be the most cost-effective recruitment method, 7 did not, and 1 study found social media equally cost-effective as compared with other methods.ConclusionsOnly 12 studies out of 30 found social media to be the most effective recruitment method. There is evidence that social media can be the best recruitment method for hard-to-reach populations and observational studies. With only 30 studies having compared recruitment through social media with other methods, more studies need to be done that report the effectiveness of recruitment for each strategy, demographics of participants recruited, and cost-effectiveness of each method.

Missing the "Target": Preventing the Unjust Inclusion of Vulnerable Children for Medical Research Studies.

The central purpose of medical research on children is to generate new knowledge that can improve children’s health, subject to ethical standards that promote justice. Incorporated in U.S. law, international law, and European Union law, the Justice Principle prohibits targeting in medical research, which is the selection of research subjects because of their manipulability and compromised position, rather than for reasons directly related to the problem being studied. Unfortunately, medical research studies involving children have too often violated the Justice Principle, by targeting children in a compromised position due to their health status and vulnerable to manipulability because of their race and class. For example, a U.S. physician implanted pacemakers in fifty-five healthy African-American children resulting in disability, while a drug company tested an unapproved antibiotic in Nigerian children suffering from meningitis causing the death of eleven children, although there was a proven therapy available to the children. To prevent the targeting of these children, I recommend the development of a Vulnerability and Equity Impact Assessment tool (VEIA) similar to the Health Equity Impact Assessment tool to determine whether it is just to select children from particular groups as research subjects. Specifically, the VEIA will measure the societal burdens borne by children as a result of their race, class, and/or health status that compromises their position and makes them vulnerable to manipulability, the potential risks of the research such as physical and psychological harm, and the prospective benefits from the research such as guaranteed access to the therapy if it works. The research study using children from particular groups should not be approved for funding and/or the drug should not be approved for use, unless based on the VEIA, the researcher shows that the benefits to children from these particular groups outweigh the burdens and the risks.

Feasibility of reusing time-matched controls in an overlapping cohort.

The methods developed for secondary analysis of nested case-control data have been illustrated only in simplified settings in a common cohort and have not found their way into biostatistical practice. This paper demonstrates the feasibility of reusing prior nested case-control data in a realistic setting where a new outcome is available in an overlapping cohort where no new controls were gathered and where all data have been anonymised. Using basic information about the background cohort and sampling criteria, the new cases and prior data are "aligned" to identify the common underlying study base. With this study base, a Kaplan-Meier table of the prior outcome extracts the risk sets required to calculate the weights to assign to the controls to remove the sampling bias. A weighted Cox regression, implemented in standard statistical software, provides unbiased hazard ratios. Using the method to compare cases of contralateral breast cancer to available controls from a prior study of metastases, we identified a multifocal tumor as a risk factor that has not been reported previously. We examine the sensitivity of the method to an imperfect weighting scheme and discuss its merits and pitfalls to provide guidance for its use in medical research studies.

Developing Tacit Knowledge of Complex Systems: The Value of Early Empirical Inquiry in Healthcare Design

Every year, more than 200,000 patients in Canada acquire an infection while receiving healthcare and more than 8,000 die as a result (Public Health Agency of Canada, 2013). Infections can arise from the entry and multiplication of a microorganism in a person’s tissue (Public Health Ontario, 2012a, 2012b). As healthcare workers perform tasks, they circulate among patients, objects, and surfaces, thereby creating opportunities for transmitting microorganisms and possibly contributing to the spread of hospital-acquired infections. Newborns hospitalized in neonatal intensive care units are particularly vulnerable because of inherent risk factors such as low birth weight, underlying illness, undeveloped immune systems, and greater skin permeability. Other risk factors include poor staff-topatient ratios, crowded environments, and exposure to invasive devices (Public Health Ontario, 2012a, 2012b). Infection prevention and control has been the subject of much study in medical and epidemiological research and a variety of best practice guidelines have been developed to support healthcare workers and related stakeholders. Yet, despite the availability of information, managing healthcare-associated infections remains a challenge because the relevant explicit knowledge is not being adequately developed and mobilized as tacit knowledge for use the front lines. Some researchers have called for a human factors perspective to help address challenges in designing for infection prevention and control, but relatively few studies have been conducted to date. Researchers also suggest that empirical inquiry is needed to better inform the design process, and particularly the design of complex systems where attention to detailed processes and interactions can support the success of an intervention. A human factors approach can help designers develop a deeper understanding of work processes, technology considerations, as well as physiological, psychological, cultural, and organizational factors. The need is particularly pressing in low-resource healthcare environments where funds, time, and human resources may be scarce and strategic design decisions based on evidence are needed to support meaningful and effective changes. With this in mind, a human factors study was conducted in an existing neonatal intensive care unit to identify the influence of product and environment design on infection prevention and control and to inform recommendations for improvement. In this case study, we illustrate how the application of an empirical, methodical approach can help design professionals and stakeholders develop tacit knowledge of complex systems – knowledge that can be used to better inform design priorities, the design process, decision making, and the allocation of resources to help maximize improvements. “ ” To know that you do not know is the best. To think you know when you do not is a disease. Recognizing this disease as a disease is to be free of it.

Coronary Artery Calcification.

Coronary artery calcification (CAC) is an established marker of subclinical atherosclerosis and an independent predictor of future coronary heart disease in the asymptomatic primary prevention population, particularly in the intermediate risk cohort. CAC also helps in reclassifying those patients and their risk of cardiovascular events into higher or lower risk categories. MESA (Multi-Ethnic Study of Atherosclerosis) is a National Heart, Lung, and Blood Institute-sponsored population-based medical research study involving 6,814 men and women from 6 U.S. communities without a medical history of clinical cardiovascular disease. The evidence from this population cohort revealed that CAC scoring was independently predictive and highly effective at risk stratification of major adverse cardiac events. This review provides available data based on MESA. We focus on the utility of CAC for cardiovascular disease risk stratification of individuals, and we describe its diagnostic value in identifying patients at risk.

A Bayesian multivariate joint frailty model for disease recurrences and survival.

Motivated by a study for soft tissue sarcoma, this article considers the analysis of diseases recurrence and survival. A multivariate frailty hazard model is established for joint modeling of three correlated time-to-event outcomes: local disease recurrence, distant disease recurrence (metastasis), and death. The goals are to find out (i) the effects of treatments on local and distant disease recurrences, and death, (ii) the effects of local and distant disease recurrences on death, and (iii) the correlation between local and distant recurrences. By our approach, all these three important questions, which are commonly asked in similar medical research studies, can be answered by a single model. We put the proposed joint frailty model in a Bayesian framework and use a hybrid Monte Carlo algorithm for the computation of posterior distributions. This hybrid algorithm relies on the evaluation of the gradient of target log density and a guided walk progress, and it combines these two strategies to suppress random walk behavior. A further distinction is that the hybrid algorithm can update all the components of a multivariate state vector simultaneously. Simulation studies are conducted to assess the proposed joint frailty model and the computation algorithm. The motivating soft tissue sarcoma data set is analyzed for illustration purpose. Copyright © 2016 John Wiley & Sons, Ltd.

An Interim LAeq8 Criterion for Impulse Noise Injury.

We present a method to account for the effects of the hearing protection devices (HPDs) for use with the 8 hours equivalent A-weighted energy (LAeq8) criterion. The method involves the calculation of the LAeq8 equivalent unprotected free-field dose (LAeq8EUFF), which is obtained by using the insertion loss (IL) data of the HPD together with free-field pressure measurements. The method was validated against the historical the U.S. Army Medical Research and Materiel Command walk-up study data with volunteers exposed to simulated large weapon noise wearing a range of HPDs. The IL data were obtained using standard acoustical test fixtures fitted with the matching HPDs in replicated field tests and using shock tubes at conditions comparable to the actual exposure intensities. Logistic regression calculations were performed to correlate the LAeq8EUFF values against the walk-up study outcomes to determine the L(95,95) threshold for the protection of 95% of the population with 95% of the time. Data comparison shows that L(95,95) is 89 dBA, which is slightly higher than the 85 dBA criterion but falls in the 80 to 90 dBA range as used by various NATO nations. Therefore, considering the limitation of the walk-up dataset, it is conservative to adopt the 85 dBA threshold for general application.

Another Dream of Common Language

Abstract Sandy Stone's “Posttranssexual Manifesto” is often regarded as the principal point of departure for transgender studies. In this 1995 interview, portions of which first appeared in Wired magazine, Stone discusses her various careers in telecommunications, medical research, recording engineering, consumer electronics, and cultural studies of media and performance. The interview has been edited to highlight Stone's persistent attention to questions of language and communication, and the relationship of these concerns to feminist and transgender theorizing.

Recommended guideline for designing and interpreting of Ramadan fasting studies in medical research

Ramadan fasting is specific intermittent fasting comprising significant changes in routine lifestyle pattern and may affect body homeostasis and metabolism. In spite of several studies conducted on the effects of Ramadan fasting on various aspects of health and disease, because of heterogeneity in methodology and procedures (sometimes inevitable), a comprehensive concluding for reliable results as in most conditions is impossible. Based on basic studies and those have been conducted in this field, this paper suggests a checklist contains, as far as possible, important factors to be considered in designing, interpreting and comparing the results of Ramadan fasting studies. Accordingly, circadian rhythm, season/latitude sensitivity, serum osmolarity and, lifestyle changes (including dietary intakes, physical activity, sleep quality and duration, smoking and, etc.) may be of great importance. Also, a close definition of the number of fasting days and it consecutively or alternatively must be presented with reference to sex. Appropriate time points for blood/urine sampling would be varied case by case.

Stem Cell Banking-Awareness and Acceptance by Expecting Mothers in Mumbai Region

<p>Stem cell technology is the breakthrough in Medical science. It seems to be the solution for all the human diseases and has the potential to change the way we live. Fatal diseases will cease to be fatal anymore with this innovation in medical science. Considering its promising endowment many countries have adopted Stem Cell Banking and Medical research and curative studies are growing in this area. This paper explores the pregnant women’s awareness and acceptance of cord blood stem cells in Mumbai region. It is an empirical study to understand the association between the ‘Awareness and Acceptance of Stem Cell Banking’ and the demographic profile of the expecting mothers, the effect of the environmental factors such as Gynecologist initiative, promotional activities of Stem Cell Banks, cost associated with storage, and attitude towards preventive health care.</p><p>Methodology adopted-Questionnaire was administered among the expecting mothers in Mumbai region and Bi-variate statistical analysis, cross tabulation, chi-square data analysis tool were adopted to understand the association among the variables defined.</p>The authors have done a substantial literature review of recent news articles and papers publications to understand the stem cell technology and its benefits. This paper highlights future scope of research that can be carried out in this area with reference to practical application so that our Government can reap the benefits of this innovation in medical science for the citizens of our country.

In vitro evidence for efficacy in food intolerance for the multispecies probiotic formulation Ecologic® Tolerance (Syngut™).

The beneficial effects of probiotics are currently the subject of extensive studies in health and medical research. The aim of this research was to specifically design a new probiotic formulation for supplementation in people suffering from food intolerance. The selection of strains was focussed on the capacity to influence mechanisms of action that are important in development of food intolerance with the following parameters measure: in vitro capacity to produce β-galactosidase, in vitro strengthening of the epithelial barrier, in vitro stimulation of cytokines produced by regulatory T cells, in addition to assessing fundamental quality criteria (stability, gastrointestinal (GI)-survival, multispecies concept, allergen-free). Ecologic®Tolerance/Syngut™ was subsequently developed consisting of a multispecies concept using 4 different probiotic strains (Bifidobacterium lactis W51, Lactobacillus acidophilus W22, Lactobacillus plantarum W21 and Lactococcus lactis W19). Each of these strains demonstrated ability to survive the GI-tract and strain specific effects in producing β-galactosidase, strengthening the gut barrier function after immunological-induced stress and inhibiting Th2 cytokines (IL-4, IL-5 and IL-13 (≥50%), in addition to stimulating interleukin-10 levels; thus, providing in vitro evidence for the efficacy of the selected strains to provide beneficial effects in patients suffering from food intolerance.

Trend-constrained corrected score for proportional hazards model with covariate measurement error.

In many medical research studies, survival time is typically the primary outcome of interest. The Cox proportional hazards model is the most popular method to investigate the relationship between covariates and possibly right-censored survival time. However, in many clinical trials, the true covariates may not always be accurately measured due to natural biological fluctuation or instrument error. It is well know that for regression analysis in general, naively using mismeasured covariates in conventional inference procedures may incur substantial estimation bias. In the presence of covariate measurement error, several functional modeling methods have been proposed under the situation where the distribution of the measurement error is known. Among them are parametric corrected score and conditional score. Although both methods are consistent, each suffers from severe problem of multiple roots or absence of appropriate root when the measurement error is substantial. The problem persists even when the sample size is practically large. We conduct a detailed investigation on the pathological behaviors of parametric corrected score and propose an approach of incorporating additional estimating functions to remedy these pathological behaviors. The estimation and inference are then accomplished by means of quadratic inference function. Extensive simulation studies are conducted to evaluate the performance of proposed method.

Knowledge and attitudes regarding medical research studies among patients with breast cancer and gynecological diseases.

BackgroundMedical research studies are becoming increasingly important for optimizing the prevention, diagnosis and treatment of illnesses. Participation in research studies can have many benefits for patients. In randomized and controlled clinical studies, they can receive the best possible medical care currently available. However, only a small proportion of patients nowadays are treated within the framework of medical research. The primary endpoint of this study was to discover what level of knowledge patients have about clinical studies and how they currently perceive them, in order to identify ways of optimizing the information provided about studies from the patients’ point of view.MethodsThe study included 2546 patients (breast cancer 21.6 %, gynecological cancer 8.3 %, obstetrics 32.7 %, endometriosis 7.8 %, fertility treatment 3.2 %, other benign gynecological illnesses 19.2 %, no information for 7.2 %) in the outpatient clinic (45.2 %) and in the in-patient sector (54.8 %) at the Department of Gynecology at Erlangen University Hospital and associated centers. In the single-center study, conducted between January 2011 and January 2012, the patients were asked about their level of knowledge regarding the background to medical research studies and the ways in which they are carried out and used. The patients were also asked how they perceived medical studies and how they thought study conditions might be optimized. The three-page questionnaire was included in the feedback sheet received by patients as part of the hospital’s quality management system.ResultsAs a whole, the group only had moderate knowledge about clinical studies. A majority of the respondents considered that studies were valuable (91.6 %), but only a few were also willing to take part in them (58.4 %). Knowledge and willingness to participate strongly depended on age (P < 0.001), educational level (P < 0.001) and patient group (P < 0.001). Most patients would prefer to decide about participating in studies through a discussion with their outpatient physicians.ConclusionsThe information that patients have about clinical studies affects whether they participate in them. It is therefore extremely important for patients to be well informed, for their anxieties about participation to be relieved, and for the benefits of participation to be explained to them.