SINFA!

Prior to Data Collection. The most effective way to work with a statistical consultant is to include him from the very beginning of the project. A statistician who is also knowledgeable in your area of research can be of great value in helping to refine and focus the research effort into an efficient, successful project.

 

An important advantage of consulting a statistician before a study begins is that she can verify that the planned procedures and size of the study will be adequate to address its goals. She can give advice on blinding/masking and randomization, the number and combination of experimental interventions, the timing of measurements or visits, and other important design issues, such as whether it would be better to collect information on a larger sample or on the same sample more times.

 

A statistician can also suggest ways to maximize the efficient use of the available resources.  It may seem that using a particular design is sensible, but in fact, the statistician may know a more efficient design. Also, a statistician routinely looks for threats to validity that might ruin a project.

 

The statistician can also contribute relevant expertise in decisions about data management from the earliest stages. Decisions about how to code measures, and what to computerize, directly affect the ease, even the feasibility, of subsequent analyses. 

 

If the statistician is consulted before the data management system is established, the items below should be discussed. If the database already exists, the statistician will need to know how all of these aspects of data management were carried out, often in detail.

Judicious use of a statistical consultant in the early stages of a project can save much time, effort, and aggravation in the later stages. "It is always easier to steer a ship than to raise it off the ocean floor."

 

After Data Have Been Collected. Although it is best to involve a statistician in the design of a study, a statistical consultant may be brought into a project after the data have been collected.

 

A statistical consultant can help to select and implement data analysis methods that are appropriate and effective for the types of data produced by your study. In order to do this, the statistician needs to have a complete, detailed description of the study design and conduct, as well as a clear exposition of the questions to be addressed.

 

A statistician should know (or may be able to develop) statistically valid ways to obtain answers to your questions. Also, she will examine your data for threats to validity, ranging from missing data to questionable outliers to confounders.

 

If the study procedures did not provide data that could answer the research question, the statistician will not be able to remedy this with statistical methods; however, she may be able to point out what information can be extracted from the data.

 

Once the data are analyzed, the results must be interpreted and conveyed to an audience, such as a regulatory agency, management, a research journal, or a media outlet. A statistician can be valuable at this stage, too, by checking that your conclusions fit the analysis results, by suggesting the best ways to describe and display the data, and by assuring that you have not made erroneous or incomplete statements about the findings.  A statistician who is first consulted at this stage may want to re-analyze the data using methods she considers more appropriate than those already tried.