Investigator-initiated trials (IIT) are often fairly complex in their methodologies. Additionally, given the large amounts of data, the results from clinical studies can be overwhelmingly difficult to understand. Therefore, it is critical that you’re able to distill your study results in a way that’s easy to understand for your audience. One of the best strategies to summarize and communicate results is through the use of tables and figures. These elements are the first things that readers look for, and it’s also likely the last thing they’ll remember about your study. In this article, we’ll discuss some guidelines that will help you produce effective tables and figures for your studies.
Tables
Tables are a great way to summarize all of the key data from your results. While it’s always great to have a lot of data, you have to be careful and selective when choosing which information to include in your tables. Too much information can create clutter and make it difficult to interpret the results. Below we’ve outlined some key formatting tips when designing your tables:
- Use clear and descriptive titles
- Create tables that can be interpreted independently without having to read the report
- Ensure that all abbreviations used in the table are spelled out
- Include units (if applicable) within the headings instead of individual cells
- Include statistics, P-values, and uncertainties (i.e. standard deviations, confidence intervals) wherever possible
- Keep the wording simple and remove any unnecessary texts
Figures
Graphical figures have always been a powerful tool to communicate scientific results. After all, a picture can mean a thousand words, or in this case, a thousand data points. There are a lot of choices when it comes to selecting the right figure for your data set. When making your selection, consider the intended purpose you want to convey – are you trying to summarize the data, compare results between test groups, or show a relationship or trend? The choice of figures will also depend on your personal style, as well as the preference of your target audience. Below are some common types of figures typically used in clinical trials:
- Flow diagrams or flow charts are often used to show the methodologies used to collect the data. For example, a flow diagram can be used to show the different stages of a clinical study, from screening participants to randomizing them into specific test groups.
- Repeated measures plots are used to evaluate a subject’s measure over a period of time. For example, in a clinical trial evaluating two different eye drops for dry eyes, you could use a repeated measure plot to show the differences in comfort scores over several visits.
- Bar graphs are used to show a comparison between various groups. For instance, using the eye drop example from above, you could use a bar graph to show the differences in tear film quality between the test group and the control.
- Scatter plots are used to depict the relationship between two different variables. For example, you would use a scatter plot to show how increasing the concentrations of lubricants in an eye drop also improves tear film quality.
Similar to tables, figures should be designed and formatted in a clear, non-cluttered fashion. A reader should be able to interpret the figures without having to read any of the texts in the results section. Some other key elements to pay attention to are:
- ensure that the axes are properly labelled and scaled
- data points also include uncertainties (i.e. confidence interval, standard error, standard deviation).
Overall, tables are a great way to summarize a lot of data, while figures are a great way to show relationships and trends within your study. Although they take a lot of time and effort to create, the end result is well worth it. When designing tables and figures, it’s always a good idea to refer to previous publications to get a sense of what is expected. It also helps to consult other experts in your field for a second opinion. For more help in designing and analyzing your results, or any aspect or your IIT, please contact Sengi.
