Chronic Renal Insufficiency Cohort Study (CRIC)

General Description

The Chronic Renal Insufficiency Cohort (CRIC) Study is an observational study that examined risk factors for progression of chronic renal insufficiency (CRI) and cardiovascular disease (CVD) among CRI patients. The study enrolled adults aged 21 to 74 years with a broad spectrum of renal disease severity, half of whom were diagnosed with diabetes mellitus. Subjects underwent extensive clinical evaluation at baseline and at annual clinic visits and via telephone at 6 month intervals. Data on quality of life, dietary assessment, physical activity, health behaviors, depression, cognitive function, health care resource utilization, as well as blood and urine specimens were collected. Measures of kidney function and occurrence of new and worsening CVD are the primary outcomes, among others.

Data from the recruitment and follow-up phases through Phase 3. Additionally, the data package includes variables related to APOL1, Echocardiogram, Electrocardiogram, and censored composite and individual outcomes. The data package includes data through 2021.

Retinal images for CRIC participants are not included in the package, but are available upon request.

Objectives

The primary objectives of the CRIC Study were to examine risk factors for progression of CKD and CVD among patients with established CKD. Additionally, the study aimed to develop predictive models to identify high-risk subgroups, informing future treatment trials, and examine the effect of ongoing clinical management on outcomes.

Outcome Measure

The primary renal outcome measure was reduction in estimated GFR. Renal events were defined as the need for renal replacement therapy (ESRD), an estimated halving of GFR, and/or a 25 ml/min per 1.73 m2 decline in GFR from baseline.

Evaluation of subclinical CVD was also used as a study outcome measure. Additionally, clinical cardiovascular outcomes (including acute myocardial infarction, heart failure, arrhythmias, stroke, and peripheral arterial disease [PAD]) were ascertained.

Criteria

The study enrolled participants with CKD aged 21 to 74 years. About one-half of the study participants were diagnosed with diabetes mellitus. Age-related entry criteria for GFR were established to limit the proportion of older individuals recruited with age-related diminutions of GFR, but otherwise nonprogressive CRI. The estimated GFR to define eligibility was based on the simplified MDRD estimating equation.
Patients diagnosed with polycystic kidney disease or on active immunosuppression for glomerulonephritis were excluded from the study.

Outcome

Major outcomes include loss of kidney function (estimated GFR, measured GFR in a subset of study participants, occurrence of end-stage renal disease-ESRD) and occurrence of cardiovascular disease (CVD). See http://www.cristudy.org/Chronic-Kidney-Disease/Chronic-Renal-Insufficiency-Cohort-Study/ for additional information.