Study Design
Social & Scientific Systems works closely with our clients to develop implementation plans to achieve study objectives in the most efficient and cost-effective manner. We routinely assist investigators with protocol design, including sampling frame recommendations, data collection methodology, and content design for forms. We also provide assistance with Institutional Review Board (IRB) and Office of Management and Budget (OMB) submissions. The developmental period frequently includes feasibility and pilot studies to test factors such as recruitment, study materials, data quality, and response rates. Feasibility studies may include power calculations to ensure an appropriate study model. In some cases, focus groups and advisory panels are used, particularly for the design of recruitment and data elements.
We have conducted studies using a variety of epidemiologic methods, including the following:
- Validation studies seek to confirm reports of disease or health outcome using followup questionnaires, physician surveys, medical record reviews, specimen collection, or clinical measurements. See Uterine Fibroids: Risk Factors for Uterine Leiomyomas or Autoimmune Disease Confirmation.
- Case-control, case-cohort, and nested case-control studies involve the recruitment of both affected and unaffected participants for a particular health outcome to look back in time and compare characteristics and risk factors that may differ between those who have the disease and those who do not. See ALS: Role of Environmental Neurotoxins in the Etiology of Amyotrophic Lateral Sclerosis or Pregnancy, Heredity, and Environment.
- Longitudinal studies follow a group of unaffected participants over time to compare disease incidence in those who are and are not exposed to potential risk factors. See the Sister Study: Genetic and Environmental Risk Factors for Breast Cancer or Agricultural Health Substudies.
- Feasibility studies seek to test key research factors, such as verifying the availability of populations and the ability to recruit participants; assuring that the protocol is fitting for the population; assessing whether the data design will produce acceptable response rates and data quality; and for clinical studies, determining whether the incidence of disease or exposure is adequately predicted. See SEAD: The Study of Estrogen and Development.
- Studies to test clinical examinations and specimen collection protocols are conducted to assess laboratory tests, examine how clinical methodologies may affect results, or compare a biological indicator in participants with or without an exposure, such as by levels of smoking, type of diet, or use of chemicals. SeeWorkers Health: Effects of Chronic Occupational Exposures to Pesticides.
- In-home studies are used to conduct extensive in-person interviews, obtain biologic measurements and specimens, and collect environmental specimens. See Agricultural Health, Farming, and Movement or Parkinson's Disease.
- Gene-environment studies examine the interaction of genes and the environment as it affects risks for disease outcome or protection. The above referenced studies typically include questionnaires to assess health and exposures histories as well as the collection of biologic specimens (such as blood, urine, tumor tissue, nail and hair clippings) and environmental sampling (such as dust, air, or allergens).