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Anesthesia and Analgesia Oct 2015Case-control and cohort studies are invaluable research tools and provide the strongest feasible research designs for addressing some questions. Case-control studies... (Review)
Review
Case-control and cohort studies are invaluable research tools and provide the strongest feasible research designs for addressing some questions. Case-control studies usually involve retrospective data collection. Cohort studies can involve retrospective, ambidirectional, or prospective data collection. Observational studies are subject to errors attributable to selection bias, confounding, measurement bias, and reverse causation-in addition to errors of chance. Confounding can be statistically controlled to the extent that potential factors are known and accurately measured, but, in practice, bias and unknown confounders usually remain additional potential sources of error, often of unknown magnitude and clinical impact. Causality-the most clinically useful relation between exposure and outcome-can rarely be definitively determined from observational studies because intentional, controlled manipulations of exposures are not involved. In this article, we review several types of observational clinical research: case series, comparative case-control and cohort studies, and hybrid designs in which case-control analyses are performed on selected members of cohorts. We also discuss the analytic issues that arise when groups to be compared in an observational study, such as patients receiving different therapies, are not comparable in other respects.
Topics: Biomedical Research; Case-Control Studies; Cohort Studies; Humans; Observational Studies as Topic; Research Design; Retrospective Studies
PubMed: 26378704
DOI: 10.1213/ANE.0000000000000861 -
European Journal of Hospital Pharmacy :... Nov 2021Paediatric inpatients are a high-risk population for drug-related problems, yet there is a lack of data concerning drug-related problems and pharmaceutical interventions... (Observational Study)
Observational Study
OBJECTIVES
Paediatric inpatients are a high-risk population for drug-related problems, yet there is a lack of data concerning drug-related problems and pharmaceutical interventions in paediatric hospitals in France. The objective of this study was to describe drug-related problems, pharmaceutical interventions and the acceptance rate of physicians based on the characteristics of both medication order and pharmaceutical interventions.
METHODS
A 12-month, monocentric, observational and prospective study was conducted from 1 June 2016 to 31 May 2017 in a French university paediatric hospital. Prescription analysis was performed at the central pharmacy. The data were collected by querying the drug prescription database of the e-prescription software. Data on drugs, prescribers, drug-related problems and interventions were recorded. The primary outcome was the measurement of the number of drug-related problems in paediatric hospitalised patients (medical and surgical wards). Secondary outcomes were classification of drug-related problems and pharmaceutical interventions. Physician acceptance of pharmaceutical interventions was additionally assessed.
RESULTS
The main types of drug-related problems were supratherapeutic dosage (33.8%), improper administration (22.9%) and subtherapeutic dosage (16.8%). A total of 1742 pharmaceutical interventions were recorded. The rate of pharmaceutical interventions was 2.48 per 100 drug prescriptions. Acceptance rate of physicians was 51.7%. Some 530 different drugs were involved. The drugs most frequently involved in pharmaceutical interventions were drugs for the nervous system (31.3%) and anti-infectives (20.2%). Pharmaceutical interventions related to dose adjustment accounted for half of the interventions ahead of drug choice interventions (35.4%).
CONCLUSIONS
This study illustrates the frequency of drug-related problems in paediatric inpatients and the ability of pharmacists to identify them in their daily work. However, it also highlights the difficulty in obtaining physician acceptance (or even clear refusal) of pharmaceutical interventions with a review of the prescription at the central pharmacy.
Topics: Child; Hospitals, Pediatric; Humans; Medication Errors; Observational Studies as Topic; Pharmacists; Pharmacy Service, Hospital; Prospective Studies
PubMed: 33115799
DOI: 10.1136/ejhpharm-2020-002319 -
Nature Reviews. Rheumatology Jul 2015Over the past decade, an increasing number of observational studies have examined the effectiveness or safety of treatments for rheumatoid arthritis. Unlike randomized... (Review)
Review
Over the past decade, an increasing number of observational studies have examined the effectiveness or safety of treatments for rheumatoid arthritis. Unlike randomized controlled trials (RCTs), however, observational studies of drug effects have methodological limitations such as confounding by indication. Active-comparator designs and new-user designs can help mitigate such biases in observational studies and improve the validity of their findings by making them more closely approximate RCTs. In an active-comparator study, the drug of interest is compared with another agent commonly used for the same indication, rather than with no treatment (a 'non-user' group). This principle helps to ensure that treatment groups have similar treatment indications, attenuating both measured and unmeasured differences in patient characteristics. The new-user study includes a cohort of patients from the time of treatment initiation, enabling assessment of patients' pretreatment characteristics and capture of all events occurring during follow-up. These two principles should be considered when designing or reviewing observational studies of drug effects.
Topics: Arthritis, Rheumatoid; Bias; Confounding Factors, Epidemiologic; Humans; Observational Studies as Topic; Randomized Controlled Trials as Topic
PubMed: 25800216
DOI: 10.1038/nrrheum.2015.30 -
Infection Control and Hospital... Oct 2016Observational studies compare outcomes among subjects with and without an exposure of interest, without intervention from study investigators. Observational studies can... (Review)
Review
Observational studies compare outcomes among subjects with and without an exposure of interest, without intervention from study investigators. Observational studies can be designed as a prospective or retrospective cohort study or as a case-control study. In healthcare epidemiology, these observational studies often take advantage of existing healthcare databases, making them more cost-effective than clinical trials and allowing analyses of rare outcomes. This paper addresses the importance of selecting a well-defined study population, highlights key considerations for study design, and offers potential solutions including biostatistical tools that are applicable to observational study designs. Infect Control Hosp Epidemiol 2016;1-6.
Topics: Antimicrobial Stewardship; Bias; Cross Infection; Databases, Factual; Epidemiologic Methods; Epidemiologic Studies; Humans; Observational Studies as Topic; Research Design
PubMed: 27322190
DOI: 10.1017/ice.2016.118 -
Seminars in Radiation Oncology Oct 2019A principle goal of research in Oncology is to determine the optimal treatment for our patients. This often takes the form of comparing 2 existing therapies to one... (Review)
Review
A principle goal of research in Oncology is to determine the optimal treatment for our patients. This often takes the form of comparing 2 existing therapies to one another to determine which is superior, or to introduce a new therapy and determine if it is superior or noninferior to the existing standard of care. This type of research is termed comparative effectiveness research (CER), and the gold-standard is through the conduct of randomized trials. This is the preferred approach, and the only true methodologic approach that can assign a cause-and-effect relationship between a treatment effect and the observed outcome. An alternative approach that is gaining popularity is the use of population-based registry analysis given that it is quicker, cheaper, and easier to perform. However, there are unavoidable forms of bias and confounding that exist when using observational research to perform CER, and recent evidence suggests that population-based CER often results in erroneous results, and that statistical methods to minimize bias are ineffective to overcome the numerous limitations of these databases. In this article, the strengths and weaknesses of both randomized and observational research will be discussed.
Topics: Comparative Effectiveness Research; Data Management; Humans; Medical Oncology; Observational Studies as Topic; Research Design
PubMed: 31472729
DOI: 10.1016/j.semradonc.2019.05.011 -
Assessment Aug 2016Observational measurement plays an integral role in a variety of scientific endeavors within biology, psychology, sociology, education, medicine, and marketing. The...
Observational measurement plays an integral role in a variety of scientific endeavors within biology, psychology, sociology, education, medicine, and marketing. The current article provides an interdisciplinary primer on observational measurement; in particular, it highlights recent advances in observational methodology and the challenges that accompany such growth. First, we detail the various types of instrument that can be used to standardize measurements across observers. Second, we argue for the importance of validity in observational measurement and provide several approaches to validation based on contemporary validity theory. Third, we outline the challenges currently faced by observational researchers pertaining to measurement drift, observer reactivity, reliability analysis, and time/expense. Fourth, we describe recent advances in computer-assisted measurement, fully automated measurement, and statistical data analysis. Finally, we identify several key directions for future observational research to explore.
Topics: Automation; Computers; Forecasting; Humans; Observational Studies as Topic; Observer Variation; Reproducibility of Results; Statistics as Topic
PubMed: 26933139
DOI: 10.1177/1073191116635807 -
Annals of the New York Academy of... Feb 2018Myasthenia gravis (MG) presents many challenges for establishing treatment efficacy through clinical trials. Among these are the rarity and heterogeneity of the disease,... (Review)
Review
Myasthenia gravis (MG) presents many challenges for establishing treatment efficacy through clinical trials. Among these are the rarity and heterogeneity of the disease, spontaneous fluctuations, prolonged latency to effect for many immunosuppressive drugs, and the uncertain generalizability of results from randomized controlled trials (RCTs). Prospective observational study designs may overcome some of these limitations, but attention is required to ensure that internal validity is not compromised. Observational comparative effectiveness research (CER) utilizes data obtained during routine clinical care to evaluate the effectiveness of interventions in real-life practice conditions, thereby improving generalizability to the clinic. Compared with RCTs, observational CER studies may be less resource intensive and costly. Recent advances that have improved the feasibility of CER studies for MG are (1) the development of MG common data elements, (2) the publication of international consensus guidance for MG treatment, and (3) the development of a web-based REDCap database that can be shared and adapted to standardize data collection. This infrastructure could be used for multisite comparisons of commonly used therapies and provides longitudinal information on patient- and clinician-centered MG outcome measures. A challenge is to design studies that address the potential limitations of observational trials, such as confounding and selection and information bias.
Topics: Comparative Effectiveness Research; Humans; Immunosuppressive Agents; Myasthenia Gravis; Observational Studies as Topic; Randomized Controlled Trials as Topic; Research Design; Treatment Outcome
PubMed: 29377158
DOI: 10.1111/nyas.13582 -
Acta Paediatrica (Oslo, Norway : 1992) May 2020Neonates frequently require supplementary oxygen but may develop complications if the oxygen saturation is outside the target range. This review aimed to determine... (Review)
Review
AIM
Neonates frequently require supplementary oxygen but may develop complications if the oxygen saturation is outside the target range. This review aimed to determine whether the algorithms used in closed loop automated oxygen control systems influenced their efficacy and whether use of the systems reduced relevant, long-term neonatal complications.
METHODS
A literature search was conducted using PubMed and Google Scholar. The search terms were 'closed loop' or 'automat*', 'oxygen' and 'neonat*'.
RESULTS
Eighteen studies were identified: sixteen comparison clinical studies, an observational study and an animal study. Overall, closed loop automated oxygen control was associated with an increased percentage of time spent within the target oxygen saturation range and there were fewer manual adjustments to the inspired oxygen concentration when compared with manual oxygen control. The systems were effective in infants on non-invasive respiratory support or mechanically ventilated, but no study included term-born infants. No long-term data were available to determine if complications of oxygen toxicity were reduced.
CONCLUSION
Closed loop automated oxygen control has been shown in short term trials including preterm and low birth weight infants to improve target saturation achievement. Whether long-term outcomes will be improved with their use requires investigation.
Topics: Humans; Hyperoxia; Infant; Infant, Newborn; Infant, Premature; Observational Studies as Topic; Oxygen; Oxygen Inhalation Therapy
PubMed: 31715041
DOI: 10.1111/apa.15089 -
BMJ Open Sep 2023Very preterm infants are at risk of abnormal microbiome colonisation in the first weeks to months of life. Several important associated factors have been identified...
INTRODUCTION
Very preterm infants are at risk of abnormal microbiome colonisation in the first weeks to months of life. Several important associated factors have been identified including gestational age, mode of delivery, antibiotic exposure and feeding. Preterm infants are at risk of a number of pathologies for which the microbiome may play a central role, including necrotising enterocolitis and sepsis. The objective of this study is to determine detailed microbiome changes that occur around implementation of different management practices including empiric antibiotic use, advancement of feeds and administration of probiotics during admission to the neonatal intensive care unit.
METHODS AND ANALYSIS
A single-site, longitudinal observational study of infants born less than 32 weeks gestation, including collection of maternal samples around delivery and breastmilk and infant samples from admission through discharge from the neonatal unit.
ETHICS AND DISSEMINATION
The protocol was approved by the Clinical Research Ethics Committee of the Cork Teaching Hospitals.The findings from this study will be disseminated in peer-reviewed journals, during scientific conferences, and directly to the study participants. Sequencing data will be deposited in public databases.
TRIAL REGISTRATION NUMBER
NCT05803577.
Topics: Humans; Infant, Newborn; Anti-Bacterial Agents; Gestational Age; Infant, Premature; Infant, Very Low Birth Weight; Microbiota; Observational Studies as Topic
PubMed: 37748849
DOI: 10.1136/bmjopen-2023-075060 -
Veterinary Pathology Sep 2018Observational studies are the basis for much of our knowledge of veterinary pathology and are highly relevant to the daily practice of pathology. However,...
Observational studies are the basis for much of our knowledge of veterinary pathology and are highly relevant to the daily practice of pathology. However, recommendations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offer advice on planning and conducting an observational study with examples from the veterinary pathology literature. Investigators should recognize the importance of creativity, insight, and innovation in devising studies that solve problems and fill important gaps in knowledge. Studies should focus on specific and testable hypotheses, questions, or objectives. The methodology is developed to support these goals. We consider the merits and limitations of different types of analytic and descriptive studies, as well as of prospective vs retrospective enrollment. Investigators should define clear inclusion and exclusion criteria and select adequate numbers of study subjects, including careful selection of the most appropriate controls. Studies of causality must consider the temporal relationships between variables and the advantages of measuring incident cases rather than prevalent cases. Investigators must consider unique aspects of studies based on archived laboratory case material and take particular care to consider and mitigate the potential for selection bias and information bias. We close by discussing approaches to adding value and impact to observational studies. Part 2 of the series focuses on methodology and validation of methods.
Topics: Animals; Observational Studies as Topic; Pathology, Veterinary; Research Design
PubMed: 30071806
DOI: 10.1177/0300985818785705