Cost comparison of asthma treatments in 12-week study: caution about matching and short observational follow-up

In the absence of randomisation, observational studies must take extra care to create treatment groups that are comparable in terms of key characteristics. Various matching methods exist which can create sound comparisons, minimising confounding where possible. A recent observational study by Dal Negro et al. carried out a cost analysis comparing two asthma medications. They report strong conclusions which favour one treatment over the other, however they include little discussion on the limitations of their study. The purpose of this letter is to comment on the weaknesses of the study design, including the level of matching used, and to urge readers to consider these issues alongside the interpretation of results.

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Study design: what’s in a name?

Acta Endocrinologica ◽

10.1530/eje-20-0873 ◽

2020 ◽

Vol 183 (6) ◽

pp. E11-E13

Author(s):

Olaf M Dekkers ◽

Rolf H H Groenwold

Keyword(s):

Observational Study ◽

Study Design ◽

Observational Studies ◽

Case Control Study ◽

Case Control ◽

Short Paper ◽

Cross Sectional ◽

Trial Intervention ◽

Control Study

The name of the study should properly reflect the actual conduct and analysis of the study. This short paper provides guidance on how to properly name the study design. The first distinction is between a trial (intervention given to patients to study its effect) and an observational study. For observational studies, it should further be decided whether it is cross-sectional or whether follow-up time is taken into account (cohort or case–control study). The distinction prospective-retrospective has two disadvantages: prospective is often seen as marker of higher quality, which is not necessarily true; there is no unifying definition that makes a proper distinction between retrospective and prospective possible.

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Importance of the Pneumococcus in Community-acquired Pneumonia in Tender-age Infants on the Background of Vaccination

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2021.6810 ◽

2021 ◽

Vol 9 (B) ◽

pp. 1525-1528

Author(s):

Aliya A. Zhanpeissova ◽

B. T. Tukbekova ◽

S. B. Akhmetova ◽

B. Dyusseno Sandugash ◽

K. Zh. Alimshaikhina ◽

...

Keyword(s):

Confidence Intervals ◽

Study Design ◽

Scientific Practice ◽

Statistical Significance ◽

Statistical Processing ◽

Community Acquired Pneumonia ◽

The Other ◽

Test Parameter ◽

Bug Fixes

«IMPORTANCE OF THE PNEUMOCOCCUS IN COMMUNITY-ACQUIRED PNEUMONIA IN TENDER-AGE INFANTS ON THE BACKGROUND OF VACCINATION» The authors of the manuscript provide data demonstrating that una pneumonia against the background of vaccination is accompanied by a change in the etiological structure. The article is a new idea and overall it is well written and structured. However, simple study design, lack of patient baseline and follow-up data limit the conclusion of withdrawal. I invite the authors to solve the following questions: 1) There are many spelling, grammatical and punctuation errors. Authors should correct mistakes and rewrite the article in a clear and understandable style. I have visited the authors with the help of a language expert on rewriting. 2) The main problem of the manuscript is poor statistical processing and statistical reporting. The authors stated: “All data were expressed as confidence intervals. Thus, it is unclear whether the etiological structure was normally distributed. Moreover, following normal scientific practice, authors should indicate specific statistical significance values when comparing each test parameter. 3) The cited literature is relevant to the research and meets the requirements of the journal. But mentions of 9/19 were published over 10 years ago. I recommend reading current research on this topic. In conclusion, the work makes a good impression. On the other hand, it can be published after significant changes with reference to the comments mentioned above, including bug fixes and rewriting of the article in a clear and easily understandable style.

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Design and Analysis of Observational Studies

International Journal of Infertility & Fetal Medicine ◽

10.5005/jp-journals-10016-1079 ◽

2014 ◽

Vol 5 (2) ◽

pp. 33-39 ◽

Cited By ~ 1

Author(s):

KP Suresh ◽

MR Gajendragad ◽

H Rahman

Keyword(s):

Observational Study ◽

Study Design ◽

Observational Studies ◽

Research Question ◽

Validity And Reliability ◽

Current Review ◽

Valid Result ◽

Methods And Techniques ◽

H Design

ABSTRACT Appropriate study design forms the basis of any successful organized research. Irrespective of the underlying rationale of the research question, inappropriate design of an experiment or execution of a study may not give a valid result. As defined, the research should have the following characteristics: it should be undertaken within the framework of a set of philosophies, should have an unbiased objective and a design comprising of methods and techniques that have been tested for their validity and reliability. These principles of research clearly emphasize the need for an appropriate study design. The current review focuses on the planning and analysis of an observational study to obtain significant and accurate findings. How to cite this article Suresh KP, Gajendragad MR, Rahman H. Design and Analysis of Observational Studies. Int J Infertil Fetal Med 2014;5(2):33-39.

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EFFECTIVENESS AND SAFETY OF INTRA-ARTICULAR HYALURONIC ACID IN ATHLETES WITH ARTICULAR LESIONS: A MULTICENTER, PROSPECTIVE OBSERVATIONAL STUDY

World Science ◽

10.31435/rsglobal_ws/30112021/7702 ◽

2021 ◽

Author(s):

Jordi Puigdellívol Grifell ◽

Juan Pérez Estévez ◽

Enrique Herrera Otto ◽

Jordi Marcos ◽

Mindaugas Gudelis

Keyword(s):

Hyaluronic Acid ◽

Observational Study ◽

Group Differences ◽

Treatment Groups ◽

Injection Group ◽

Study Results ◽

Patient Reported ◽

Promising Treatment ◽

Multicenter Prospective Observational Study

Objective: To evaluate the effectiveness and safety of a novel intra-articular formulation of hyaluronic acid (HA) to treat athletes with articular lesions. Methods: Multicenter, prospective, interventional, observational study analyzing the clinical evolution of athletes who received 2 or 3 intra-articular injections of HA. The study was scheduled in Visit 1 (week 0), Visit 2 (week 1), Visit 3 (week 2), Visit 4 (week 3), and Visit 5 (end of follow up, week 24). The change in Visual Analog Scale (VAS) of pain and in Knee Injury and Osteoarthritis Outcome Score (KOOS) and the rate of return to physical activity were evaluated upon treatment initiation for up to 24 weeks. The incidence of adverse events was recorded throughout the study. Results: Sixty patients were recruited: 28 (46.7%) in the 2-injection group and 32 (53.3%) in the 3-injection group. Mean VAS gradually decreased across the visits, with statistically significant reductions in both groups from Visit 2 to Visit 3 and to Visit 5 (P < 0.0001). Inter-group differences in the change in VAS from Visit 2 to Visit 5 were statistically comparable (P = 0.8271). At Visit 5, the KOOS of all subscales statistically improved in both treatment groups. At the end of follow-up (Visit 5), 75.9% of patients returned to sport in the overall population. Only one patient reported an adverse event. Conclusion: This novel formulation of HA is effective and safe for at least 24 weeks, resulting in a promising treatment option for athletes with articular lesions.

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Renin-angiotensin system inhibitors and severity of SARS-CoV-2 infection: a meta-analysis

10.21203/rs.3.rs-29483/v1 ◽

2020 ◽

Author(s):

Teodoro J. Oscanoa ◽

Xavier Vidal ◽

Alfonso Carvajal ◽

Roman Romero-Ortuno

Keyword(s):

Study Design ◽

Observational Studies ◽

Data Extraction ◽

Meta Analysis ◽

Severe Disease ◽

Renin Angiotensin System ◽

Angiotensin Ii Receptor ◽

Converting Enzyme Inhibitors ◽

Mortality Effect

Abstract Introduction The mechanism of entry of SARS-CoV-2 into the human host cell is through the ACE2 receptor. During the pandemic, a hypothesis has been proposed that Angiotensin-converting enzyme inhibitors (ACEi) and Angiotensin II receptor blockers (ARBs) could be risk factors for the development of severe SARS-CoV-2 infection. Objective To conduct a meta-analysis of the association between ACEi or ARB use and SARS-CoV-2 infection severity or mortality.Data Sources We searched PubMed, EMBASE, Google scholar and the Cochrane Database of Systematic Reviews for observational studies published between December 2019 and April 24, 2020Study Selection: Studies were included if they contained data on ACEi or ARB use and SARS-CoV-2 infection severity or mortality. Effect statistics were pooled using random-effects models. The quality of included studies was assessed with the Newcastle–Ottawa Scale (NOS). Data ExtractionData on study design, study location, year of publication, study design, number of participants, sex, age at baseline, outcome definition, exposure definition, follow-up, effect estimates and 95% Cis.Results Thirteen observational studies were identified for inclusion, combining to a total sample of 14364 participants. Mean age was 59.2 (SD 7.3) years and 53.5% were men. Mean follow-up was 28.3 (14.2) days. The mean NOS score of included studies was 7.8 (range: 7-9). Results suggested that ACEi or ARB use did not increase the risk of severe disease or mortality from SARS-CoV-2 infection (OR=0.72, 95% CI 0.47-1.11, p= 0.138).ConclusionsAt present, the limited evidence available does not support the hypothesis of increased SARS-CoV-2 risk with ACEi or ARB drugs. However, more evidence needs to accumulate before this controversy can be resolved.

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Risk of bias in observational studies using routinely collected data of comparative effectiveness research: a meta-research study

BMC Medicine ◽

10.1186/s12916-021-02151-w ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Van Thu Nguyen ◽

Mishelle Engleton ◽

Mauricia Davison ◽

Philippe Ravaud ◽

Raphael Porcher ◽

...

Keyword(s):

Selection Bias ◽

Study Design ◽

Comparative Effectiveness ◽

Observational Studies ◽

Research Study ◽

Effectiveness Research ◽

Essential Information ◽

Routinely Collected Data ◽

Immortal Time Bias

Abstract Background To assess the completeness of reporting, research transparency practices, and risk of selection and immortal bias in observational studies using routinely collected data for comparative effectiveness research. Method We performed a meta-research study by searching PubMed for comparative effectiveness observational studies evaluating therapeutic interventions using routinely collected data published in high impact factor journals from 01/06/2018 to 30/06/2020. We assessed the reporting of the study design (i.e., eligibility, treatment assignment, and the start of follow-up). The risk of selection bias and immortal time bias was determined by assessing if the time of eligibility, the treatment assignment, and the start of follow-up were synchronized to mimic the randomization following the target trial emulation framework. Result Seventy-seven articles were identified. Most studies evaluated pharmacological treatments (69%) with a median sample size of 24,000 individuals. In total, 20% of articles inadequately reported essential information of the study design. One-third of the articles (n = 25, 33%) raised some concerns because of unclear reporting (n = 6, 8%) or were at high risk of selection bias and/or immortal time bias (n = 19, 25%). Only five articles (25%) described a solution to mitigate these biases. Six articles (31%) discussed these biases in the limitations section. Conclusion Reporting of essential information of study design in observational studies remained suboptimal. Selection bias and immortal time bias were common methodological issues that researchers and physicians should be aware of when interpreting the results of observational studies using routinely collected data.

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Observational Study Design in Veterinary Pathology, Part 1: Study Design

Veterinary Pathology ◽

10.1177/0300985818785705 ◽

2018 ◽

Vol 55 (5) ◽

pp. 607-621 ◽

Cited By ~ 4

Author(s):

Jeff L. Caswell ◽

Laura L. Bassel ◽

Jamie L. Rothenburger ◽

Andrea Gröne ◽

Jan M. Sargeant ◽

...

Keyword(s):

Observational Study ◽

Study Design ◽

Observational Studies ◽

Daily Practice ◽

Temporal Relationships ◽

Different Types ◽

Observational Study Design ◽

Veterinary Pathology ◽

Incident Cases ◽

Selection Of

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.

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The Value of Phenobarbital in the Child Who Has Had a Single Febrile Seizure: A Controlled Prospective Study

PEDIATRICS ◽

10.1542/peds.59.3.378 ◽

1977 ◽

Vol 59 (3) ◽

pp. 378-385 ◽

Cited By ~ 1

Author(s):

Sheldon M. Wolf ◽

Andrew Carr ◽

David C. Davis ◽

Sherwood Davidson ◽

Earle P. Dale ◽

...

Keyword(s):

Recurrence Rate ◽

Febrile Seizure ◽

Febrile Convulsion ◽

Febrile Seizures ◽

The Other ◽

Treatment Groups ◽

Parental Resistance ◽

Significant Difference ◽

The Mean

A group of 355 children who were seen after a first febrile convulsion at the Kaiser Foundation Hospitals in Southern California from 1970 to 1975 were randomly assigned to three treatment groups—daily phenobarbital, "intermittent" phenobarbital given at the onset of fever, and no phenobarbital. We found that 42% had a relative with a febrile seizure and 16% a relative with an afebrile convulsion. 13% had seizures which were either lateralized or longer than ten minutes. Parents were unaware of the fever prior to the seizure in about 30% of the cases. In 81% the preseizure duration of fever was less than 24 hours. The mean follow-up was 28 months, with a range of 6 to 70 months. There was no significant difference in the recurrence rate between children receiving "intermittent" as compared with no phenobarbital. The recurrence rate in children receiving daily phenobarbital was significantly decreased compared to either of the other two groups. Severe recurrent febrile seizures occurred in no children on daily phenobarbital and in 4.4% of the children receiving either intermittent or no phenobarbital. Parental resistance, compliance, and reversible hyperactivity were the main problems encountered with the continuous phenobarbital regimen.

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Case Study on Post-Discharge Persistence or Reappearance of Respiratory Symptoms in COVID-19 Hypoxia Patients

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2021/v33i37a31976 ◽

2021 ◽

pp. 31-39

Author(s):

Jayshree Kharche ◽

Deepak S. Khismatrao ◽

Reshma Patil ◽

Rajkumar Nikalje

Keyword(s):

Natural History ◽

Observational Study ◽

Study Design ◽

Respiratory Symptoms ◽

Oxygen Therapy ◽

Post Discharge ◽

Respiratory Problems ◽

History Of

Introduction: News published about persistence or reappearance of symptoms in Covid 19 is worrisome. However, only one study from Italy is observed in this reference. Aim: the current study is conducted to study persistence or reappearance of especially respiratory symptoms amongst COVID 19 hypoxia patients. Study Design: Post-discharge follow-up, observational study with the telephonic interview of Covid 19 hypoxia patients from a dedicated Covid 19 hospital in India. Methods: Sixty-two patients were interviewed 1 – 3 months post-discharge to elicit history on persistence or reappearance of respiratory symptoms. Results: out of the results many patients doesnot show any symptoms compared to female, male are more prone to respiratory problems. Thus, the oxygen therapy showed proof that males are more prone to illness and depict the symptoms compared to females. Conclusion: A large multi-centric year-long study is recommended to further conclude on the natural history of the disease.

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Atmospheric Pressure Change Measurement: An Observational Study

10.21203/rs.3.rs-1161314/v1 ◽

2021 ◽

Author(s):

Kuat Oshakbayev ◽

Gulnara Bedelbayeva ◽

Khalit Mustafin ◽

Abdul Sabir ◽

Attila Tordai

Keyword(s):

Observational Study ◽

Study Design ◽

Atmospheric Pressure ◽

Pressure Change ◽

Indirect Measurement ◽

Liquid Volume ◽

Change Measurement ◽

Air Volume

Abstract Introduction: The aim of the study was to show an atmospheric pressure change by indirect measurement in hermetically closed vessels during four years of follow-up.Methods: Study design: an observational study. In hermetically sealed elastic bottles with different liquids were measured differences in liquid and air volumes from baseline to final follow-up period. The physical law of flotation was used to measure liquid and air volume above liquid in bottles. To measure liquid and air (above liquid) volumes in each bottle was used the physical law of buoyancy. The follow-up period was four years.Results: The volumes of liquid and air in all bottles were decreased after the follow-up period to 14.38±2.40 and 36.25±3.37 ml, respectively. Air volume in comparison to liquid volume decreased more than two times significantly (P=0.0007) after the follow-up period.Conclusions: Thus, atmospheric pressure increased during the last 4-year follow-up period. Further investigations are needed.

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