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

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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Observational Study Design in Veterinary Pathology, Part 2: Methodology

Veterinary Pathology ◽

10.1177/0300985818798121 ◽

2018 ◽

Vol 55 (6) ◽

pp. 774-785 ◽

Cited By ~ 3

Author(s):

Jeff L. Caswell ◽

Laura L. Bassel ◽

Jamie L. Rothenburger ◽

Andrea Gröne ◽

Jan M. Sargeant ◽

...

Keyword(s):

Observational Study ◽

Observational Studies ◽

Study Groups ◽

Primary Sources ◽

Specificity And Sensitivity ◽

Large Numbers ◽

Observational Study Design ◽

Veterinary Pathology ◽

Study Population ◽

Quantitative Analyses

Observational studies are a basis for much of our knowledge of veterinary pathology, yet considerations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offered advice on planning and carrying out an observational study. Part 2 of the series focuses on methodology. Our general recommendations are to consider using already-validated methods, published guidelines, data from primary sources, and quantitative analyses. We discuss 3 common methods in pathology research—histopathologic scoring, immunohistochemistry, and polymerase chain reaction—to illustrate principles of method validation. Some aspects of quality control include use of clear objective grading criteria, validation of key reagents, assessing sample quality, determining specificity and sensitivity, use of technical and biologic negative and positive controls, blinding of investigators, approaches to minimizing operator-dependent variation, measuring technical variation, and consistency in analysis of the different study groups. We close by discussing approaches to increasing the rigor of observational studies by corroborating results with complementary methods, using sufficiently large numbers of study subjects, consideration of the data in light of similar published studies, replicating the results in a second study population, and critical analysis of the study findings.

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Case-Control Studies – An Efficient Observational Study Design

Nephron Clinical Practice ◽

10.1159/000242442 ◽

2010 ◽

Vol 114 (1) ◽

pp. c1-c4 ◽

Cited By ~ 6

Author(s):

Karlijn J. van Stralen ◽

Friedo W. Dekker ◽

Carmine Zoccali ◽

Kitty J. Jager

Keyword(s):

Observational Study ◽

Study Design ◽

Case Control ◽

Case Control Studies ◽

Observational Study Design

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Medication safety research by observational study design

International Journal of Clinical Pharmacy ◽

10.1007/s11096-016-0285-6 ◽

2016 ◽

Cited By ~ 1

Author(s):

Kim S. J. Lao ◽

Celine S. L. Chui ◽

Kenneth K. C. Man ◽

Wallis C. Y. Lau ◽

Esther W. Chan ◽

...

Keyword(s):

Observational Study ◽

Study Design ◽

Medication Safety ◽

Safety Research ◽

Observational Study Design

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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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Effect of Laryngeal Mask Air Way Insertion versus Endotracheal Intubation over Hemodynamic Responses in Pediatrics Patient Who Underwent Ophthalmic Surgery at Menelik II Hospital, Addis Ababa: A Prospective Observational Study Design

Anesthesiology Research and Practice ◽

10.1155/2020/7021641 ◽

2020 ◽

Vol 2020 ◽

pp. 1-6

Author(s):

Mohammed Suleiman Obsa ◽

Azeb Lencha Sholla ◽

Betelhem Girma Baraki ◽

Getahun Dendir Welde ◽

Temesgen Bati Gelgelu ◽

...

Keyword(s):

Blood Pressure ◽

Observational Study ◽

Study Design ◽

Prospective Observational Study ◽

Pressor Response ◽

Laryngeal Mask ◽

Observational Study Design ◽

Baseline Values ◽

The Mean ◽

Mean Differences

Background. The airway of an anesthetized child is usually maintained with an endotracheal tube or laryngeal mask airway. However, both are related with some level of pressor response which may be risky in several groups of patient. Methods. An institutional-based prospective observational study design was employed. A systematic random sampling technique was used to select study participants. Data were entered into Epi info version 7 and transported to SPSS version 20 for analysis. Normality of the data was checked using Shapiro–Wilk tests. An independent t test was used to determine the mean differences between the two groups while the paired sample t test was used to determine the mean differences within the groups. A p value of less than 0.05 was used as a cut-off point for the presence of association. Results. The changes in systolic and diastolic blood pressure were returned to baseline values at five and three minutes in both groups, respectively. However, the changes in the heart rate and mean arterial pressure returned to baseline values in five minutes in the ETT group and three minutes in the LMA group. At baseline, the difference in systolic blood pressure between the two groups was not statistically significant (p=0.328). Conclusions. A significant hemodynamic pressor response was observed after the insertion of both LMA and ETT groups. However, the LMA group has less hemodynamic change as compared to the ETT group. Therefore, the practice of LMA insertion was strongly recommended.

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