Who is in this study, anyway? Guidelines for a useful Table 1

Area of Science:

• Epidemiology
• Biostatistics
• Medical Research Methodology

Background:

• Table 1 is crucial for presenting study sample characteristics in research papers.
• Effective Table 1 design can reveal potential threats to internal and external validity.
• Limited guidance exists for designing Table 1, especially for complex studies.

Purpose of the Study:

• To summarize and extend existing literature on reporting descriptive statistics in Table 1.
• To develop reporting recommendations for Table 1 based on study design.
• To enhance transparency regarding potential threats to study validity.

Main Methods:

• Synthesized existing guidelines and literature.
• Developed reporting recommendations for Table 1.
• Focused on study design and validity.

Main Results:

• Described a basic structure for Table 1 with modifications for columns, rows, and cells.
• Highlighted variations for analytic complexities like missing data, sample weights, clustered data, and interaction.
• Discussed tradeoffs between comprehensiveness and reader-friendliness.

Conclusions:

• The developed recommendations aim to guide authors in designing Table 1.
• Attention to reader perspective is key for effective Table 1 layout.
• Improved Table 1 design enhances the assessment of study validity.