Critical Appraisal of the Scientific Literature

Outline Components of a scientific paper Types of study The Hierarchy of Evidence Common mistakes in the literature

Components of a Scientific Paper Introduction (Background) Materials/Subjects and Methods Results Discussion Conclusion

Introduction Outline of previous research related to present study Leads to aims and objectives of present study Clearly stated goals or objectives Hypothesis - Null

Ethical / Internal Review Board Approval

Materials / Subjects A detailed description of the materials used including brand names A detailed description of how the sample was selected Power calculation…

Subjects Are they representative of the target population? Were they randomly selected? Inclusion and exclusion criteria Are experimental groups matched (Age, sex etc)? Is there a control group?

Methods Should describe in great detail how the study was carried out It should enable the reader to potentially replicate the study

Results Should list as simply as possible the data that specifically addresses the original objectives or hypothesis of the study Should be concise and to the point

Statistical Analyses Selection of appropriate statistical tests according to the type of data gathered Study of interactions between various variables Analysis should be as simple as possible

Discussion Relates finding of present study to previous information in the field Author can give their own opinion on the importance or application of the results of the study

Conclusions Clear conclusions based on the results The “take-home” message of the study

Types of Studies Descriptive / Observational Cross-Experimental Sectional Longitudinal “Traditional” Review Systemic Review Meta Analysis The Cochrane Collaboration

The Hierarchy of Evidence Case Report Case series Retrospective comparative studies Prospective Comparative studies Randomized Prospective Controlled Trial Meta of Randomized Controlled Trial

Common Mistakes in the Literature Objectives not clearly stated Hypothesis (Null) not stated Introduction too long No ethical approval Sample selection not clearly defined

Common Mistakes in the Literature Methods not clearly described Use of statistical analyses to find meaningful results Results too long and not relevant Results not clinically significant Conclusions not based on results

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