The Study Design and Biostatistics (SDAB) Core works closely with existing resources to provide targeted study design and biostatistics support to ITMAT/CTSA investigators. The Core serves as a direct provider of services, including protocol review, study design, proposal development, and performance of simple to potentially substantial complex analyses. SDAB integrates the support available with the HUP and CHOP Clinical and Translational Research Centers (CTRCs), the expertise and resources of faculty in the Center for Clinical Epidemiology and Biostatistics / Department of Biostatistics and Epidemiology (CCEB/DBE), the Biostatistics Analysis Center (BAC), and the Biostatistics and Data Management Core (BDMC) at CHOP.
"The primary goal of the statistical data analysis is to perform the analyses pertaining to the research questions of interest to the investigator, which are best presented as the specific aims of the study. Methods employed range from the most basic descriptive statistics to state-of-the-art statistical methods that may involve multi-stage modeling, resampling methods for estimation and statistical tests, and, in some cases, development of new methods. More information on the latter item may be found under the Biostatistics and Epidemiology Program (BEMP).
In many cases, when they have sufficient training to do so and access to appropriate software, investigators perform analyses themselves with guidance from SDAB members. This type of support is especially important to investigators on training grants. Alternatively, a member of the BAC/DBMC, supported by the CTSA, is available to conduct limited analyses, with funding arrangements made for more extensive needs. This component of the SDAB is crucial to the success of the core, both for investigators with limited expertise and/or resources, and for the application of more complicated methodology. Manuscript support is included as part of data analysis and includes composition of methods sections, production and/or review of tables and other statistical results presented, as well as interpretation of results and contribution to discussion sections of manuscripts as appropriate."
"The SDAB Core supports the investigators in making database and data management decisions and complying with regulatory issues relating to confidentiality and security of data. In this capacity, core members work directly with the ITMAT Center for Biomedical Informatics in Translation (BIIT) Appropriate data capture is crucial to the validity of not only to the overall integrity of a study, but also to statistical analysis. For example, many methods for longitudinal data analysis require repeated measurements on subjects to be in rows, rather than columns. Consultation on this type of issue at the design stage of a study can considerably reduce work required to transform datasets at the analysis stage. Core members consult with the entity that will manage the data and define clearly the statistical needs in order to later support the analysis of the data.
With the availability of REDCap, investigators are encouraged to use it or similar systems for analysis, rather than simple spreadsheets. Dr. Cucchiara serves as a consultant for investigators intending to use that resource. More complicated studies, or trials subject to a strong regulatory component, may require the use of Oracle Clinical. BAC members in the SDAB Core have extensive experience coordinating data management and analysis of data from Oracle Clinical in collaboration with BIIT, and will continue in the next period. These tasks include the overall data structure, data formats, creation of derived variables, and identification of potential data entry errors or outliers. Analysts may also be involved in the creation of validation rules at the database level, determining what types of checks and cross-form checks are needed in real time. These tasks outline an important collaboration with the BIIT, who also provide consultations in turn."
"Assistance in planning studies entails helping to define the study question and then moving from the scientific question to an appropriate study design. Design issues include study endpoints, the type of design, and feasibility in terms of sample size requirements, implementation issues, and cost. Core members help investigators focus and refine study hypotheses. For example, if a proposed study design is not feasible in terms of costs, an experienced biostatistician and/or epidemiologist can help refocus the question or change the design, such as reducing the number of endpoints or measurements, while maintaining the goal of getting answers to relevant scientific hypotheses.
The study design assistance of the SDAB Core is also integrated with the Research Ethics Program Core (REP). For example, it is common for ethical considerations to be involved in the choice of study designs; a purely "optimal" study design in terms of statistical science may not be feasible due to ethical considerations regarding particular populations, such as pediatric studies, appropriateness of randomization, choices of control groups, or timing of informed consent. Members of the REC are available for the study design process, to provide expertise when the areas overlap."