Introduction

This original chapter breaks down the basic components of a journal article. Common statistical methods are introduced and different types of scientific studies are defined. Insight is provided on how to critically analyze scientific literature.

I. Components of a Standard Article

1. 
   

   Introduction

   
   
   
   
   1. 
      

      Sets the groundwork for the manuscript.

      
      
   2. 
      

      Provides background information detailing why the research question is being asked:

      
      
      
      
      1. 
         

         Typically acknowledges gaps in knowledge.

         
         
      2. 
         

         Reinforces the clinical relevance of the topic.

      
      
   3. 
      

      Clearly defines the research question(s).

   
   
2. 
   

   Methods

   
   
   
   
   1. 
      

      Should be sufficiently complete to allow the reader to duplicate the study, if desired.

      
      
   2. 
      

      Description of the inclusion/exclusion criteria, intervention (i.e., study arms), how data was gathered and analyzed, and ethical approval (if applicable).

   
   
3. 
   

   Results

   
   
   
   
   1. 
      

      Succinct and clear presentation of study findings. A well-written results section is organized and follows a logical progression. When applicable, data presentation should mimic the order in which research questions are posed in the last paragraph of the introduction.

      
      
   2. 
      

      Figures/tables should always be referenced in the text of the manuscript.

      
      
   3. 
      

      Interpretation of study findings should not be included in this section.

   
   
4. 
   

   Discussion

   
   
   
   
   1. 
      

      Perhaps the least relevant part of the manuscript for the knowledgeable reader.

      
      
   2. 
      

      Perhaps the most important part of the manuscript for the reader with minimal knowledge.

      
      
   3. 
      

      Recognize that author opinions are often expressed in this section (these may be incorrect).

      
      
   4. 
      

      Pay close attention to a description of study weaknesses.

      
      
      
      
      1. 
         

         Study limitations should be appropriately identified.

         
         
      2. 
         

         The impact of limitations and weaknesses should be explained.

      
      
   5. 
      

      Allows study results to be placed into context of the recent literature.

      
      
   6. 
      

      Directions of future investigations outlined.

   
   
5. 
   

   Abstract

   
   
   
   
   1. 
      

      Should provide concise summary of study.

      
      
   2. 
      

      Often the only part of the article that is read by the public.

      
      
   3. 
      

      If findings are interesting, care is required to verify if the abstract and the body of the manuscript are consistent with each other.

      
      
   4. 
      

      Do the authors draw conclusions based upon their data? (Answer: not always).

   
   
6. 
   

   Title

   
   
   
   
   1. 
      

      Should grab attention without being flashy.

      
      
   2. 
      

      Is the title an accurate portrayal of the study report? (Answer: not always).

II. Types of Studies

1. 
   

   Experimental (▶ Fig. 5.1 )

   

   
   
   
   
   1. 
      

      Prospective, randomized controlled trial:

      
      
      
      
      1. 
         

         One or more interventions with a “control” group.

         
         
      2. 
         

         Patient enters study at beginning of treatment via a randomization process and data is gathered moving forward.

         
         
      3. 
         

         Defined end points.

         
         
         
         
         • 
           

           i. Primary outcome: Did the intervention change the rate of occurrence of this outcome? For example, did infection of an open fracture requiring surgical intervention occur more or less frequently with the intervention than in the control group? These are usually discrete (yes/no, defined time points, quantifiable).

           
           
         • 
           

           ii. Secondary outcomes: Did the intervention change rates of occurrence for one or more other outcomes? For example, did patients with open fractures in the intervention group report improved or poorer outcomes than in the control group? These should be as discrete as possible but could be qualitative.

      
      
   2. 
      

      Prospective cohort comparison study (nonrandomized controlled trial):

      
      
      
      
      1. 
         

         Gathers data moving forward for similar patients provided two or more differing treatments determined by other factors besides randomization.

         
         
      2. 
         

         Less controlled studies at risk of selection bias (e.g., surgeon preference, patient desires, etc.).

   
   
2. 
   

   Observational

   
   
   
   
   1. 
      

      Descriptive:

      
      
      
      
      1. 
         

         Retrospective case series:

         
         
         
         
         • 
           

           i. Report of a group of patients with a similar condition and/or treatment without any comparison group.

           
           
         • 
           

           ii. Often represents a report of a single individual’s or institution’s experience.

           
           
         • 
           

           iii. May be beneficial if reporting a group of patients with bad outcomes, in that it can help guide physicians away from dangerous interventions (e.g., Kirschner wire fixation of femur fractures results in 100% nonunion rates and 95% infection rates).

           
           
         • 
           

           iv. Limited value if reporting a group of patients with good outcomes, in that it does not provide evidence that the intervention is better or worse than other commonly accepted interventions.

      
      
   2. 
      

      Analytical:

      
      
      
      
      1. 
         

         Prospective cohort study:

         
         
         
         
         • 
           

           i. Gathers data moving forward on a novel treatment without a different intervention group.

           
           
         • 
           

           ii. Patients are identified based on exposure (e.g., femur fracture) and followed over time to determine who develops a particular outcome of interest (e.g., infection, nonunion).

           
           
         • 
           

           iii. Prospective cohort study with historical controls. Data collected are analyzed and compared to data already in existence at a given institution or to historical reports in the literature.

         
         
      2. 
         

         Retrospective cohort comparison studies:

         
         
         
         
         • 
           

           i. Data is already in existence at the time of study development.

           
           
         • 
           

           ii. Normally entail medical record review (and radiographic review if applicable).

           
           
         • 
           

           iii. Two or more different treatments are then compared based upon data already in existence with respect to the development of an outcome(s) of interest.

           
           
         • 
           

           iv. Disadvantage—if data points do not exist, then a potentially important question may not be answered.

         
         
      3. 
         

         Case-control study:

         
         
         
         
         • 
           

           i. Retrospective study that determines if an exposure is associated with an outcome.

           
           
         • 
           

           ii. Patients with a specific outcome or disease such as arthritis (“the cases”) are compared to patients without arthritis (“the control”) and the incidence of potential risk factor(s), such as obesity, are explored in both groups.

           
           
         • 
           

           iii. Better for rare outcomes as smaller numbers are necessary.

         
         
      4. 
         

         Cross-sectional study.