Study Measures
The CARRS Cohort core annual survey is administered by trained interviewers in face-to-face visits at the participants’ home using a tablet-based application. Questionnaires and assessments are conducted to capture repeated measures of cardiometabolic disease risk factors, health behaviors, and sociodemographic factors, as shown in the measures table below.
The CARRS Cohort is also linked to multi-level exposome assessments, including measures of air pollution, neighborhood food and built environment. Ancillary studies have piloted genetic, epigenetic, and metabolomic profiling, and collection of social network data. One randomly selected eligible man and one randomly selected eligible woman were sampled from each household, enabling studies of within-household factors and social influences.
In line with the strategic vision for the CARRS Cohort, data collection has been expanded to incorporate more granular exposure and outcome assessment modalities in the Precision Cardiovascular Disease Phenotyping and Pathophysiological Pathways in the CARRS Cohort (Precision-CARRS) initiative. Precision-CARRS will revolutionize the cardiovascular disease (CVD) prevention and care paradigm from imprecise prediction with focus on late stage disease to personalized and precise prediction with improved understanding of early-stage disease to maintain cardiovascular health. Some of the key measures are shown below.
CARRS COHORT STUDY MEASURES
| Domain | Variables | Measurement |
|---|---|---|
| Questionnaires and Wearables | ||
| Socio-demographic | Contact information, age, sex, income, education, occupation, social caste, place of birth, marital status, household size | Questionnaire |
| Health Behaviors | Dietary habits, physical activity, alcohol use, tobacco use, sleep duration and quality, COVID-19 | Modified food frequency questionnaire (FFQ), international physical activity questionnaire (IPAQ), sleep habits questionnaire, and other locally validated instruments |
| Family History | Family history of hypertension, diabetes mellitus, dyslipidemia,heart disease,stroke | Self-report |
| Physician Diagnosis of Disease | Previously diagnosed hypertension, diabetes mellitus, dyslipidemia, heart disease, stroke, chronic pulmonary disease (COPD) | Self-report / medical records |
| Medication Use | Cholesterol, glucose, lipid, and blood pressure-lowering medication | Self-report |
| Psychosocial | Depression, health-related quality of life (QoL) | Patient health questionnaire (PHQ-9) and EuroQol (EQ-5D) questionnaire |
| Environmental | ||
| Ambient Air Pollution | Daily average PM2.5 at 1kmx1km spatial resolution | B-attenuation monitors, gravimetric samplers |
| Built Environment | Vegetation index, road networks, gridwise built-up area %, intersections, light intensity, locations of pollution sources | Satellite observations and land use maps |
| Cardiometabolic Risk Factors and Outcomes | ||
| Anthropometry | Weight, height, waist and hip circumference | Tanita BC-418, Seca-213 stadiometer, tape measure |
| Blood Pressure | Systolic and diastolic blood pressure | Automated Omron HEM-7080 |
| Glucose and Insulin | Fasting, 30-min, 2-hour blood glucose; glycated hemoglobin A1c (HbA1c); fasting, 30-min, 2-hr insulin; C-peptide | Hexokinase, HPLC electrochemiluminescence immunoassay |
| Lipid Markers | Total cholesterol, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol; triglycerides | Direct method, Friedewald equation, Martin/Hopkins equation if triglyceride >400 mg/dl, enzymatic method |
| Renal Function | Serum and urine creatinine, albumin:creatinine ratio, cystatin C | Jaffe kinetic, spot urine, immunoturbidimetry |
| Cardiovascular Events | Heart failure, myocardial infarction, stroke, angina revascularization, peripheral artery disease | Symptoms, history, electrocardiogram (EKG), medical records | Mortality | Verbal autopsy |
PRECISION-CARRS STUDY MEASURES
Echocardiography is not currently available in the CARRS Cohort but will be added in future followups.
| Domain | Variables | Measurement | †Real-time health behaviors | Total steps, sleep duration | Actiwatch |
|---|---|---|
| †Ecological momentary assessment | Periodic daily stress appraisals | Smartphone application |
| Hepatic steatosis | Hepatic fat deposition | CT Scan |
| Inflammation thrombogenesis | High sensitivity C-reactive protein (hs-CRP), soluble urokinase plasminogen activator receptor (suPAR) | Abbott Labs |
| Myocardial infarction | High sensitivity troponin-I | Abbott Labs |
| Myocardial stress | B-type natriuretic peptide | Abbott Labs |
| †Genomics | Genotypes | GWAS Array |
| †Epigenomics | DNA methylation | EPIC beadchip |
| †Metabolomics | Circulating metabolites | Liquid chromatography, mass spectrometry |
| Arterial stiffness | Pulse wave velocity, augmentation index | SphygmoCor, AtCor |
| Arterial thickness | Carotid intima media thickness (CIMT) | Ultrasound | Atherosclerosis | Carotid plaque, coronory calcium (CAC) | Ultrasound, multidetector computed tomography (MDCT) | Ventricular function | Systolic/diastolic function | Echocardiogram | Advanced lipids | Apolipoproteins A1 and B; lipoprotein a (Lpa); homocysteine | Abbott labs | Adipokines | Leptin, adiponectin | Elisa assay |
† Subsamples only