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BMC Medical Research Methodology Dec 2019All clinical research benefits from transparency and validity. Transparency and validity of studies may increase by prospective registration of protocols and by...
BACKGROUND
All clinical research benefits from transparency and validity. Transparency and validity of studies may increase by prospective registration of protocols and by publication of statistical analysis plans (SAPs) before data have been accessed to discern data-driven analyses from pre-planned analyses.
MAIN MESSAGE
Like clinical trials, recommendations for SAPs for observational studies increase the transparency and validity of findings. We appraised the applicability of recently developed guidelines for the content of SAPs for clinical trials to SAPs for observational studies. Of the 32 items recommended for a SAP for a clinical trial, 30 items (94%) were identically applicable to a SAP for our observational study. Power estimations and adjustments for multiplicity are equally important in observational studies and clinical trials as both types of studies usually address multiple hypotheses. Only two clinical trial items (6%) regarding issues of randomisation and definition of adherence to the intervention did not seem applicable to observational studies. We suggest to include one new item specifically applicable to observational studies to be addressed in a SAP, describing how adjustment for possible confounders will be handled in the analyses.
CONCLUSION
With only few amendments, the guidelines for SAP of a clinical trial can be applied to a SAP for an observational study. We suggest SAPs should be equally required for observational studies and clinical trials to increase their transparency and validity.
Topics: Data Interpretation, Statistical; Humans; Observational Studies as Topic; Reproducibility of Results; Research Design
PubMed: 31818263
DOI: 10.1186/s12874-019-0879-5 -
Tumori Dec 2023Observational trials are crucial to assess the generalizability in the real world of evidence deriving from registration studies. Despite the unquestionable importance...
Observational trials are crucial to assess the generalizability in the real world of evidence deriving from registration studies. Despite the unquestionable importance of this type of studies, Italian researchers have had to face many obstacles over the years, mainly due to ambiguous definitions and to a complex but at the same time incomplete legislation. The regulatory adjustments to the European Regulation 536/2014 have further complicated the operating and operational framework, making observational research a real "Cinderella" of the Italian system.
Topics: Italy; Observational Studies as Topic
PubMed: 37029687
DOI: 10.1177/03008916231166469 -
Medwave Sep 2019Observational studies evaluate variables of interest in a sample or a population, without intervening in them. They can be descriptive if they focus on the description... (Review)
Review
Observational studies evaluate variables of interest in a sample or a population, without intervening in them. They can be descriptive if they focus on the description of variables, or analytical when comparison between groups is made to establish associations through statistical inference. Cross-sectional studies and ecologicalalso called correlationalstudies are two observational methodological designs. Cross-sectional studies collect the data of the exposure variable and the outcome at the same time, to describe characteristics of the sample or to study associations. Ecological studies describe and analyze correlations among different variables, and the unit of analysis is aggregated data from multiple individuals. In both types of studies, associations of interest for biomedical research can be established, but no causal relationships should be inferred. This is the second of a methodological series of articles on general concepts in biostatistics and clinical epidemiology developed by the Chair of Scientific Research Methodology at the School of Medicine, University of Valparaíso, Chile. In this review, we address general theoretical concepts about cross-sectional and ecological studies, including applications, measures of association, advantages, disadvantages, and reporting guidelines. Finally, we discuss some concepts about observational designs relevant to undergraduate and graduate students of health sciences.
Topics: Biomedical Research; Biostatistics; Cross-Sectional Studies; Humans; Observational Studies as Topic; Research Design
PubMed: 31596838
DOI: 10.5867/medwave.2019.08.7698 -
American Journal of Epidemiology May 2019Much of the intellectual tradition of modern epidemiology stems from efforts to understand and combat chronic diseases persisting through the 20th century epidemiologic... (Review)
Review
Much of the intellectual tradition of modern epidemiology stems from efforts to understand and combat chronic diseases persisting through the 20th century epidemiologic transition of countries such as the United States and United Kingdom. After decades of relative obscurity, infectious disease epidemiology has undergone an intellectual rebirth in recent years amid increasing recognition of the threat posed by both new and familiar pathogens. Here, we review the emerging coalescence of infectious disease epidemiology around a core set of study designs and statistical methods bearing little resemblance to the chronic disease epidemiology toolkit. We offer our outlook on challenges and opportunities facing the field, including the integration of novel molecular and digital information sources into disease surveillance, the assimilation of such data into models of pathogen spread, and the increasing contribution of models to public health practice. We next consider emerging paradigms in causal inference for infectious diseases, ranging from approaches to evaluating vaccines and antimicrobial therapies to the task of ascribing clinical syndromes to etiologic microorganisms, an age-old problem transformed by our increasing ability to characterize human-associated microbiota. These areas represent an increasingly important component of epidemiology training programs for future generations of researchers and practitioners.
Topics: Anti-Infective Agents; Causality; Communicable Disease Control; Communicable Diseases; Data Interpretation, Statistical; Disaster Planning; Epidemiologic Methods; Humans; Observational Studies as Topic; Population Surveillance; Public Health Practice; United Kingdom; United States; Vaccines
PubMed: 30877295
DOI: 10.1093/aje/kwy264 -
International Journal of Radiation... Sep 2014The radiation oncology community has witnessed growing interest in observational research conducted using large-scale data sources such as registries and claims-based... (Review)
Review
The radiation oncology community has witnessed growing interest in observational research conducted using large-scale data sources such as registries and claims-based data sets. With the growing emphasis on observational analyses in health care, the radiation oncology community must possess a sophisticated understanding of the methodological considerations of such studies in order to evaluate evidence appropriately to guide practice and policy. Because observational research has unique features that distinguish it from clinical trials and other forms of traditional radiation oncology research, the International Journal of Radiation Oncology, Biology, Physics assembled a panel of experts in health services research to provide a concise and well-referenced review, intended to be informative for the lay reader, as well as for scholars who wish to embark on such research without prior experience. This review begins by discussing the types of research questions relevant to radiation oncology that large-scale databases may help illuminate. It then describes major potential data sources for such endeavors, including information regarding access and insights regarding the strengths and limitations of each. Finally, it provides guidance regarding the analytical challenges that observational studies must confront, along with discussion of the techniques that have been developed to help minimize the impact of certain common analytical issues in observational analysis. Features characterizing a well-designed observational study include clearly defined research questions, careful selection of an appropriate data source, consultation with investigators with relevant methodological expertise, inclusion of sensitivity analyses, caution not to overinterpret small but significant differences, and recognition of limitations when trying to evaluate causality. This review concludes that carefully designed and executed studies using observational data that possess these qualities hold substantial promise for advancing our understanding of many unanswered questions of importance to the field of radiation oncology.
Topics: Checklist; Comparative Effectiveness Research; Databases, Factual; Diffusion of Innovation; Health Care Costs; Health Services Research; Health Surveys; Insurance Claim Review; Medicare; Neoplasms; Nomograms; Observational Studies as Topic; Professional Practice; Propensity Score; Publication Bias; Radiation Oncology; Rare Diseases; Registries; Research Design; SEER Program; United States
PubMed: 25195986
DOI: 10.1016/j.ijrobp.2014.05.013 -
Journal of the American Pharmacists... 2023Inpatient hypoglycemia is associated with increased morbidity and mortality. After a hypoglycemic event, the likelihood of additional episodes increases. The Joint... (Observational Study)
Observational Study
BACKGROUND
Inpatient hypoglycemia is associated with increased morbidity and mortality. After a hypoglycemic event, the likelihood of additional episodes increases. The Joint Commission recommends evaluating all episodes of hypoglycemia for root-cause analysis. Studies have shown that pharmacists' involvement with glycemic control protocols can prevent hypoglycemia.
OBJECTIVES
This study aimed to assess whether the implementation of pharmacists' real-time assessment of hypoglycemic events using an electronic alert messaging system contributes to the reduction of the number of recurrent hypoglycemia during hospitalization.
PRACTICE DESCRIPTION
A community hospital that provides a wide range of health care services. The pharmacy department provides fully decentralized clinical services and team-based specialist services.
PRACTICE INNOVATION
The pharmacist-led hypoglycemia stewardship initiative included a comprehensive review of hypoglycemic alerts received via an automated message. The alerts generated in the electronic health record (EHR) every time a patient's blood glucose resulted in less than 70 mg/dL if there was a documented administration of a hypoglycemic agent 48 hours before the hypoglycemia event. Once the alert was received by the pharmacists via an EHR in-basket, a real-time review was conducted to identify the potential causes of the event and opportunities for therapy modification.
EVALUATION METHODS
A single-center retrospective observational study including a pre- and post-implementation phase from January 1 to June 3, 2020, and January 1 to June 30, 2021, respectively. Continuous data were analyzed using paired and equal variance t test. Noncontinuous data were analyzed using Fisher exact and chi-square test. Descriptive statistics were used to describe distribution and frequency of data.
RESULTS
There was a 5.1% absolute reduction in recurrent hypoglycemic events (P < 0.001) and a 0.6% reduction of severe hypoglycemic days (P = 0.269) in the postimplementation group. The average time to pharmacist intervention was 4 (± 3.5) hours with a 92% acceptance rate.
CONCLUSION
This study demonstrated the utility of pharmacist-led hypoglycemia reviews in the reduction of recurrent hypoglycemic events in the inpatient setting.
Topics: Humans; Blood Glucose; Hypoglycemia; Hypoglycemic Agents; Observational Studies as Topic; Pharmaceutical Services; Pharmacists; Pharmacy; Retrospective Studies
PubMed: 37696492
DOI: 10.1016/j.japh.2023.09.002 -
BMJ Open Aug 2023This study's overarching goal is to examine the relationship between brain circuits and suicidal thoughts and behaviours (STBs) in a transdiagnostic sample of US... (Observational Study)
Observational Study
INTRODUCTION
This study's overarching goal is to examine the relationship between brain circuits and suicidal thoughts and behaviours (STBs) in a transdiagnostic sample of US military veterans. Because STBs have been linked with maladaptive decision-making and disorders linked to impulsivity, this investigation focuses on valence and inhibitory control circuits.
METHODS AND ANALYSIS
In this prospective, observational study, we will collect functional MRI (fMRI), cognitive and clinical data from 136 veterans (target sample size) recruited from the Providence VA Health System (PVAHS): 68 with STBs and 68 matched controls. Behavioural data will be collected using standardised measures of STBs, psychiatric symptoms, cognition, functioning and medical history. Neuroimaging data will include structural, task and resting fMRI. We will conduct follow-up interviews and assessments at 6, 12 and 24 months post-enrolment. Primary analyses will compare data from veterans with and without STBs and will also evaluate whether activation and connectivity within circuits of valence and inhibition covary with historical and prospective patterns of suicidal ideation and behaviour.
ETHICS AND DISSEMINATION
The PVAHS Institutional Review Board approved this study (2018-051). Written informed consent will be obtained from all participants. Findings from this study will be published in peer-reviewed journals and presented at local, regional, national and international conferences.Nauder Namaky, Ph.D.* [email protected].
Topics: Humans; Impulsive Behavior; Neuroimaging; Observational Studies as Topic; Prospective Studies; Suicidal Ideation; Veterans
PubMed: 37586858
DOI: 10.1136/bmjopen-2022-070654 -
Statistical Methods in Medical Research Apr 2015Post-licensure medical product safety surveillance is important for detecting adverse events potentially not identified pre-licensure. Historically, post-licensure... (Review)
Review
Post-licensure medical product safety surveillance is important for detecting adverse events potentially not identified pre-licensure. Historically, post-licensure safety monitoring has been accomplished using passive reporting systems and by conducting formal Phase IV randomized trials or large epidemiological studies, also known as safety surveillance or pharmacovigilance studies. However, crucial gaps in the safety evidence base provided by these approaches have led to high profile product withdrawals and growing public concern about unknown health risks associated with licensed products. To address the limitations of existing surveillance systems and to facilitate more accurate and rapid detection of safety problems, new systems involving active surveillance of large, population-based cohorts using observational health care databases are being developed. In this article, we review common statistical methods that have been employed previously for post-licensure safety monitoring, including data mining and sequential hypothesis testing, and assess which methods may be promising for potential use within this newly proposed prospective observational cohort monitoring framework. We discuss gaps in existing approaches and identify areas where methodological development is needed to improve the success of safety surveillance efforts in this setting.
Topics: Biostatistics; Clinical Trials, Phase IV as Topic; Cohort Studies; Data Mining; Databases, Factual; Device Approval; Equipment Safety; Humans; Observational Studies as Topic; Product Surveillance, Postmarketing; Prospective Studies
PubMed: 22138688
DOI: 10.1177/0962280211413452 -
Multiple Sclerosis (Houndmills,... Nov 2016Randomised clinical trials are the primary source of evidence, guiding the use of disease-modifying drugs in multiple sclerosis. However, the spectrum of questions that... (Review)
Review
Randomised clinical trials are the primary source of evidence, guiding the use of disease-modifying drugs in multiple sclerosis. However, the spectrum of questions that can be answered in the trial setting is relatively narrow. 'Real-world' observational data analysis has always been the major source of evidence for epidemiology, aetiology, outcomes and prognostics, but is now also increasingly used to study treatment effectiveness. While analyses of observational cohorts typically offer superior power, generalisability and duration of follow-up relative to prospective randomised trials, they are also subject to multiple biases. It is the role of researchers to mitigate bias and to ensure the results of observational studies are robust and valid. In this review of observational data research, we provide an overview of the inherent biases, the available mitigation strategies, and the state and direction of contemporary treatment outcomes research. The review will help clinicians critically appraise published results of observational studies.
Topics: Humans; Multiple Sclerosis; Observational Studies as Topic; Outcome Assessment, Health Care
PubMed: 27270498
DOI: 10.1177/1352458516653667 -
The Journal of Trauma and Acute Care... Dec 2021While the concept of a "target trial"-optimizing the quality of observational studies by attempting to emulate the ideal world conditions of a randomized controlled... (Review)
Review
BACKGROUND
While the concept of a "target trial"-optimizing the quality of observational studies by attempting to emulate the ideal world conditions of a randomized controlled trial-was first expounded over a decade ago, the take up of this concept in the design and analysis of trials in trauma is lacking. The target trial approach avoids common errors in observational research to increase its scientific validity as well as potentially enable causal questions to be answered without the expense and intricacies of a randomized controlled trial. This review article briefly introduces the reader to the concepts and utility of a "target trial" approach before providing demonstrations of its application in the subject area of chest trauma.
METHODS
Four articles published in the last 5 years-two case control and two cohort studies-are chosen and considered in terms of their causal question; study population; inclusion and exclusion criteria; designation of time 0; clarity of the follow-up period; study outcomes; methods to minimize confounding; results; overall issues regarding study time; and the presence of avoidable errors such as introduction of immortal time bias or information bias.
RESULTS
Two of the studies had an unclear causal question; none of the studies designated a time 0; the follow-up period was unclear for all but one of the studies; and one study had a serious issue with information bias resulting from differential misclassification.
CONCLUSION
Failure to emulate a "target trial" framework may lead to serious methodologic issues in observational research. Expansion of the awareness of this approach in trauma literature will improve the quality of our observational research and potentially translate into significant benefits for our patients.
Topics: Bias; Humans; Observational Studies as Topic; Quality Improvement; Randomized Controlled Trials as Topic; Research Design; Thoracic Injuries
PubMed: 34369436
DOI: 10.1097/TA.0000000000003375