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Research Proposal • Data collection – Components of the study • Baseline – what, where, when and how • Follow-up – what, where, when and how • Questionnaire, interview, venipuncture, physical measurements, medical record review – Develop a figure that depicts data collection for each participant.
Research Proposal Enrollment (n=50) Bariatric Patients Pre-surgery Full Exam GCRC Surgery Liver Biopsy OR 4 -week Post-OP Full Exam GCRC 3, 6, 9 -month Post-OP Brief Exam GCRC Figure 3. Study Components Enroll 600 women Prenatal Examination GCRC Medical Record Abstraction Delivery Cord Blood 6 -week Examination GCRC Mother and Child Components 1 -year Examination GCRC Mother and Child Components Telephone Interview 2 week 3 month 6 month 9 month Figure 5. 1. Components of the proposed study 12 -month Post-OP Full Exam GCRC
Research Proposal • Data collection – Main Exposure and Outcome Variables • Details on what will be collected for these variables • Questionnaires – – Developed for this study? Has it been validated in race/ethnic, age, gender? What language will be used? » If you are studying acculturation how will it impact your study if questionnaires are only available in English – Scale or a score, need to provide information on the range of values, how it is scored and interpreted, what type of variable is the output (continuous, discrete, ordinal, nominal)
Research Proposal • Data collection – Main Exposure and Outcome Variables • Details on what will be collected for these variables • Laboratory assays – Variation – How standardized are the measurements. » Are there different analytical techniques? » Does it matter which one you use? – Batch variation – is this a problem – Biologic variation – is this a problem – Upper and lower bounds – Reliability coefficient, same person different days, same sample different times – Where will the assays be completed. Will samples be stored and measured all at once or will they be sent as acquired.
Research Proposal • Data collection – Main Exposure and Outcome Variables • Details on what will be collected for these variables • Standardized measurements – Blood pressure, ultrasound, MRI – Need a standardized protocol for how you will measure it » Clinical protocol is not good enough » Good starting spot – Need a standardized protocol for how you will read it » Clinical protocol is not good enough » May need repeatability studies for scanning/reading » Blinded
Research Proposal • Data collection – What is the final information that will be obtained » DXA – percent body fat » MRI – visceral adiposity, amount of fat in kg » Carotid ultrasound – intima media thickness » The focus of your study – may be a lot of information available but what is central to your study.
Research Proposal • Data collection – Main Exposure and Outcome Variables • Details on what will be collected for these variables • Case definitions – Define exposure, outcome or study population – Clinical definition – not ideal » Standard criteria » What information are needed to make the diagnosis » How will you get that information: Abstract medical record or measure required variables to obtain all required information » Develop algorithm to define disease - missing data
Research Proposal • Data collection – Confounders -- covariates • Identify potential confounders – Comorbidities – Age, sex, race, SES • Observational study – these can make or break • Less information on measurement of these variables
Research Proposal • Data analysis – For each hypothesis write out your exposure and outcome. – Indicate variable to be used in analysis for both the exposure and outcome. • Continuous, categorical, nominal or ordinal – Power calculation for that hypothesis
Research Proposal • Theoretical model – Exposure Outcome – Covariates – where do they enter in
Research Proposal Microbiome Incretin/Satiety Hepatocyte Metabolism Diet/ Physical Activity Obesity ↕ Visceral Adiposity Insulin Resistance ↕ Impaired Insulin Secretion Diabetes Hepatic Steatosis Figure 4. Aim 1 Conceptual Framework; Proposed etiology of diabetes and hepatic steatosis in morbidly obese patients prior to gastric bypass surgery.
Research Proposal • Problems, Pitfalls and limitations – Keep a running list of problems with your study