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Welch Center Resources: Study Databases



Sample Size
and Description

Activating Consumers to Exercise in Community Psychiatry through Peer SupportRandomized Controlled TrialExercise intervention with and without peer support for 100 persons with severe mental illness. Includes submaximal treadmill test data, accelerometry, DEXA scans, blood pressure, weight, waist circumference and questionnaire information.

Assessing Patient Outcomes
in Pediatric ESRD

Retrospective cohort 100 incident pediatric ESRD patients, ages 12-19, from the U.S. Renal Data System Database followed for 5 years to assess how clinical and nonclinical factors affect survival and hospitalizations.

Functional Outcomes in Pediatric ESRD

Cross-sectional and
longitudinal cohort
180 pediatric patients with renal insufficiency followed to assess functional outcome over time as they progress from renal insufficiency to ESRD to transplant.

Impact of Pediatric Specialty Care on Treatment Decisions for Children with Kidney Disease

Cross-sectionalRandomized case vignettes from 600 adult and pediatric nephrologists, assessing factors affecting treatment decisions in ESRD.

Adolescent Hemodialysis Study

Cross-sectional and
longitudinal cohort
Cross-sectional clinical performance measures on 460 adolescents on hemodialysis, ages 12-19, linked to survival and hospitalization data from the U.S. Renal Data System.
Chronic Kidney Disease Epidemi-ology Collaboration (CKD-EPI)Cross-sectionalPooling project of 10,000 individuals with measured GFR in research and clinical populations aimed at improving estimation of kidney function. A subset of ~3,000 individuals have Cystatin C measures.
CKD-EPI Pooling ProjectCross-sectional

Pool data on 5,500 research subjects and patients with measured GFR, standardized serum creatinine, and clinical characteristics. For a subset stored specimen are available and used for assaying new markers of kidney function.

Choices in Healthy Outcomes in Caring for ESRD

Longitudinal cohortMulti-center prospective longitudinal cohort study of 928 incident dialysis patients comparing outcomes for hemodialysis and peritoneal dialysis.

EQUAL study

Longitudinal cohortFollow-up to the CHOICE cohort, which focuses on process of care and quality of care for 928 incident dialysis patients in 80 centers across the country.
Kidney Disease in Children (CKiD)Prospective Cohort StudyProspective cohort of 540 children aged 1-16 yrs. with mild to moderate CKD in the U.S. and Canada to be followed for 5 years to assess risk factors for kidney disease progression, and the effect of progression on cardiovascular disease risk factors, cognition, behavior, growth.
Fatty Liver Disease and Hepatic Energy Homeostasis in Look AHEADProspective cohort within a randomized control trialA study to examine the prevalence and correlates of non-alcoholic fatty liver disease) in a high-risk population of 300 people with type 2 diabetes and obesity.
African-American Study of Kidney Disease (AASK)Randomized control trialRandomized controlled trial for 1,092 hypertensive African-American adults to determine if treatment for hypertension would prevent the progression of kidney disease.
AASK CohortProspective cohortPredictors of direct progression in 730 patients remaining from the AASK.
Chronic Renal Insufficiency Cohort Prospective cohortPredictors of progression of renal disease in 2,000 CRI adults.
Family Investigation of Nephropathy and Diabetes (FIND)Cross-sectionalThis is a case-control study of 1,000 African-Americans with ESRD and their African-American spouse/partner controls without ESRD. Interviews conducted to assess comorbidities and health behaviors. Stored specimens include DNA, serum, whole blood in everyone and urine in the controls.
ECHO: Enhancing Communication and HIV OutcomesRandomized Controlled Trial240 patients with HIV and 24 HIV providers. Pilot study to test the efficacy of an intervention to improve communication related to medication adherence among patients with HIV.
PREMIERRandomized control trialEffects of a comprehensive lifestyle intervention on blood pressure in 400 participants.
MACRONUTRIENTRandomized control trialEffects of macro-nutrients on blood pressure (feeding study; 200 participants).
DASHRandomized control trialFeeding study of 456 participants that tested the effects of three dietary patterns on blood pressure.
DASH-SodiumRandomized control trialEffect of the DASH diet and sodium intake on blood pressure (feeding study; 412 participants).
OMNI HeartRandomized control trialA randomized, three period, crossover feeding study (164 persons)  to compare the effects on CVD risk factors of three diets: 1) a carbohydrate-rich diet, 2) a diet rich in protein, and 3) a diet rich in unsaturated fat.
EURAMICCase controlLarge (2,000) international case-control study of antioxidants and risk of MI and breast cancer
CLUE IIProspective cohortSpecimen bank (30,000) of serum, red blood cells, buffy coat and toe nails, plus lifestyle information to perform epidemiologic study of cancer and cardiovascular disease.
Atherosclerotic Risk in Communities StudyProspective cohortProspective observational cohort of 6,245 individuals in four U.S. communities with detailed information on cardiovascular disease risk factors.
Atherosclerosis Risk in Communities (ARIC) Community SurveillanceSurveillance of Coronary Heart Disease~400,000 community members;  > 80,000 chart abstractions. Systematic abstraction of coronary heart disease and related ICD-9 codes with known sampling fractions to represent four US communities (Washington County, MD, Suburban Minneapolis, MN, Forsyth County, NC, Jackson, MS). Includes coded ECGs and death follow-up and committee review of events. Starting 2004 includes congestive heart failure reviews.
Atherosclerosis Risk in Communities (ARIC) MRI StudyCross-sectionalCarotid MRI with gadolinium in 1,200 individuals with thick carotid arteries and 800 individuals drawn randomly from the rest of the ARIC cohort. Interview including dietary assessment and CESD, clinic examination, extensive laboratory assessment and stored specimen for ancillary studies.
Precursor’s StudyProspective cohortProspective observational cohort of 1,152 medical students from classes 1948-1964.

Commonwealth Fund 2001 Healthcare Quality Survey

Cross-sectionalSurvey of healthcare quality in 7,000 U.S. household-based adults. Ethnic minorities were oversampled.
Diabetes Prevention Program and Outcomes Study (DPPOS)Randomized Controlled Trial and Follow-up Study The primary objective of the DPPOS is to evaluate the long-term effects of active DPP interventions on: 1) continued prevention or delay of diabetes, 2) composite diabetes-related microangiopathic and neuropathic outcome and 3) composite cardiovascular disease outcome.
Action for Health in Diabetes (Look AHEAD)Randomized Controlled Trial318 patients at JHU, 5145 nationwide. The primary objective of Look AHEAD is to examine, in overweight volunteers with type 2 diabetes, the long-term cardiovascular and mortality effects of an intensive lifestyle intervention designed to achieve and maintain weight loss.
Quality for Improvement in Depression StudyRandomized control trialRandomized controlled trial of 1,200 adults with major depression to test methods to improve treatment of depression in primary care office settings.
Childhood Development After Cochlear ImplantationProspective Cohort188 children with CI, 97 children with normal hearing. Cohort study to evaluate the predictive value of clinical variables as they relate to developmental outcomes, including oral language acquisition, speech recognition, psycho-social development and quality of life.

Project Sugar 2 

Randomized control trialTrial of nurse-community health worker intervention (550 patients) to improve care of urban African Americans with type II diabetes mellitus
Preventable Mortality in Maryland Medicaid Recipients with Severe Mental IllnessRetrospective CohortStudy of 26,000 Maryland Medicaid recipients with and without severe mental illness to examine factors related to mortality including quality of care for schizophrenia, bipolar disorder and depression using Medicaid administrative data. Includes patient safety chart review of several hundred hospital charts to determine factors related to adverse event in medical and surgical hospitalizations for persons with mental illness.
Patient-Physician Partnership to Improve Hypertension AdherenceRandomized control trialRandomized controlled trial with 2x2 factorial design to improve hypertension care by both activating patients and improving physicians’ communication skills; 50 physicians, 500 patients.
BRIDGE StudyRandomized control trialRandomized controlled trial to improve care for African Americans with depression. Includes a physician intervention and a patient intervention; 30 primary care physicians, 250 patients.
Respect, Trust, and Pain Management Quality in Patients with Severe Sickle Cell DiseaseCohort StudyAssessment of interpersonal and pain management experiences of 100 patients with SCD over one year of follow-up.
Weight Loss MaintenanceRandomized controlled trialLong-term behavioral intervention trial with 1,032 subjects that tested the effects of three different strategies to maintain weight loss.
National Ambulatory Care Survey (NAMCS)Ongoing, cross-sectionalInformation on office-based medical care including diagnoses, treatments and procedures; 10,000 per year
National Health and Nutrition Examination Surveys (NHANES)Cross-sectional, some with cohortDetailed health information from representative sample of US citizens, including laboratory measures; study size varies.

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