Over approximately 10 years, incidence of ESRD was 0.5, 8.3, 12.1, and 34.5 per 1,000 person-years for American Indian participants with no CKD, CKD stage 1, stage 2, and stages 3-5, respectively.
In the same time period, incidence was 0.7, 4.1, and 53.9 per 1,000 person-years, for those no albuminuria, microalbuminuria, and macroalbuminuria at baseline, respectively.
Chart Explanation: Crude incidence of end-stage renal disease was high in this cohort. By the third exam, the rate was 0.5 per 1,000 person-years for those with no evidence of CKD at baseline, compared to 8.3, 12.1, and 34.5 per 1,000 person-years for those with CKD stage 1, stage 2, and stages 3-5, respectively. For those without albuminuria, the rate was 0.7 per 1,000 person-years, versus 4.1 and 53.9 for those with micro- and macroalbuminuria, respectively.
The Strong Heart Study consisted of several components and three study exams (baseline, 1989-1992; second exam, 1993-1995; and third exam, 1998-1999), followed by morbidity and mortality surveillance of 4,500 tribal participants. Strong Heart enrolled men and women aged 45-74 at baseline from 13 American Indian tribes/communities in Arizona, Oklahoma, and the Dakotas. A total of 3,705 Strong Heart participants had both baseline information on both kidney function (eGFR) and albuminuria (albumin:creatinine ratio) and information on treated ESRD status at the third exam, ascertained by self-report.
|Description of Measure||Incidence of ESRD|
|Data Source||Strong Heart Study|
|Type of Data Source||Private|
|Health Care System Data||No|
|Regional or National?||National|
|Demographic Group||American Indians aged 45-74 from 13 tribes/communities |
|Numerator||Number of participants initiating treatment for ESRD by third exam|
|Denominator||All participants free of ESRD at baseline exam who survived to third exam|
|Definition of CKD||No CKD, eGFR >90 ml/min/1.73 m2 & albumin:creatinine ratio <30 mg/g|
Stage 1, eGFR >90 ml/min/1.73 m2 & albumin:creatinine ratio >30 mg/g
Stage 2, eGFR 60-89 ml/min/1.73 m2 & albumin:creatinine ratio >30 mg/g
Stages 3-5, eGFR <60 ml/min/1.73 m2
|Glomerular filtration rate||Calculated by MDRD-4 Study equation|
|Proteinuria||Spot urine albumin:creatinine ratio|
|Primary Data Source Indicator||Rate of initiating ESRD treatment, by self-report|
|Primary Indicator Method of Measurement||Questionnaire|
|Frequency of Measurement (Primary)||Once (cross-sectional at third exam)|
|U.S. Region Covered by Primary Variable||Arizona, Oklahoma, and the Dakotas|
|Period Currently Available||1989–1999|
|Pending Data||Possible continued passive follow-up only|
|Additional Data Items of Interest||Age, gender, diabetes, hypertension|
|Limitations of Indicator||Loss to follow-up may introduce bias into the measurement of incident ESRD|
|Analytical Considerations||Analysis performed by SHS investigators; denominators for each study exam and indicator must be defined properly|