Study Design Considerations Mia Papas, Marci Drees, Claudine Jurkovitz University of Delaware Christiana Care Health System January 7, Outline Role of an epidemiologist Hierarchy of research study designs Considerations for any type of study design: Choosing study population Sample size & sampling plan Study implementation and quality control Designing questionnaires, interviews & surveys 2 "Every path to a new understanding begins in confusion." Mason Cooley Why do we do research? CCHS What is Research? inquire into systematic investigation purposeful The Research Process The steps of any population health research project are: Definition of Epidemiology Distribution and Determinants of Health and Disease in Human Populations Study of. To enable. Prevention and Control of Health Problems Last JM: A Dictionary of Epidemiology, 4 th ed. New York, Oxford University Press, 2000. The Research Process The steps of any population health research project are: Epidemiology and the Research Process The steps of any population health research project are: Epidemiologist 12 Research is like the house.. 13 Research is like the house.. Epidemiology provides the foundation Science and Art: Causal Associations Statistical methods cannot establish proof of a causal relationship in an association. The causal significance of an association is a matter of judgment which goes beyond any statement of statistical probability Surgeon Generals Report, 1964 The Epidemiologic Lens Adapted from S Cole, 2002 (unpublished) and M Maclure, Causal Effect Confounding Selection Observed Effect ^ Information * * Errors in measurement and missing data ^ Includes the play of chance Epidemiologic Method Descriptive Data Hypotheses Test Hypotheses Develop Interventions Test Interventions Intervene Surveillance Analytic Studies Surveillance Evaluation Studies 18 The Tao of Epidemiology As an epidemiologist I know many non-epidemiologist colleagues think that all we do is count things. We do count things, it's true (although we also do things that don't depend on counting), but the trick is not in counting them but in: figuring out who and what to count, where to find the things to count once you figured what to count, when to count them, how to count them, how to organize what you've counted in a way to reveal the patterns you are interested in, and finally trying to figure out what the counts mean. Revere, July 28 th, 2009; Effect Measure Blog 20 Components of the Research Process 1.Choosing study population 1.Sample size & sampling plan 1.Study implementation and quality control 1.Designing questionnaires, interviews & surveys 21 1. LARC (White) Objectives: Assess parental preferences about LARC Measurements: Surveys. Target n=100 Study population: Delaware parents? 22 Components of the Research Process 1.Choosing study population 1.Sample size & sampling plan 1.Study implementation and quality control 1.Designing questionnaires, interviews & surveys 23 2. Baseline health (Ellis) Objectives: Assess baseline health in North Charleston before new terminal operations Measurements: Validated surveys. Target n=42 in each of 7 neighborhoods. Study population: North Charleston 24 Components of the Research Process 1.Choosing study population 1.Sample size & sampling plan 1.Study implementation and quality control 1.Designing questionnaires, interviews & surveys 25 3. Inclusion in fitness programs (Obrusnikova) Objectives: Assess effectiveness of SLP in young adults with intellectual disabilities (ID), with and without video. Measurements: Successfully completing video recorded exercises. Target n=6. Study population: Young adults with ID 26 Components of the Research Process 1.Choosing study population 1.Sample size & sampling plan 1.Study implementation and quality control 1.Designing questionnaires, interviews & surveys 27 4. Healthy food (Karpyn) Objectives: Evaluate effects of healthy food offerings at zoo concessions; impact of Tastimals character Measurements: profits. Customer surveys (n=200). Study population: Zoo attendees. 28 Components of the Research Process 1.Choosing study population 1.Sample size & sampling plan 1.Study implementation and quality control 1.Designing questionnaires, interviews & surveys 29 5. Palliative care (ODonnell) Objectives: Assess unmet palliative care needs of homebound patients Measurements: Survey. Target n=? Study population: VNA patients? Not clear how stratified by disease. 30 Components of the Research Process 1.Choosing study population 1.Sample size & sampling plan 1.Study implementation and quality control 1.Designing questionnaires, interviews & surveys 31 Questions? 32