Table 1.

Use of existing data sources for safety studies in subgroups of ESRD patients

Dialysis PopulationPrimary Sources of Data and Limitations (55)Comorbidity Data QualityOutcome Data QualityComments
Incident<65 yrMedicare eligibility begins at day 90; majority not covered by Medicare at initiationDepends on private insurance database and link to LDOAccuracy and completeness limited by potential changes in insurance coverage with onset of ESRDLikely younger, healthier population; some databases with long time lag
Privately insured patients retain private insurance as primary payer for 30 mo before Medicare eligibilityCMS Form 2728 universally collected but limitations on variables included/accuracyLDO, EGHP, and DOPPS data available for assessing hospitalization and death
Only 26.1% of patients 45–64 yr and 13.2% of patients 20–44 yr have Medicare coverage at baselineInformation on cause of death may be limited
Ascertainment of outcomes or baseline comorbidities may require EGHP, DOPPS, or LDO data
Incident>65 yr79.9% of patients 65–89 yr and 82.2% of patients ≥90 yr have Medicare as primary payerMedicare/USRDSSome outcomes may need validationTime lag anticipated to be shorter in near future
Excellent for patients≥65 yr with preceding claims
CMS Form 2728 universally collected but with limitations on variables included/accuracy
May need access/link to private insurance or LDO for patients 65–66 yr
Prevalent83% have Medicare primary payerMedicareSome outcomes may need validationTime lag anticipated to be shorter in near future
May exclude healthier, younger, privately insured patients; could supplement with EGHP, DOPPS, or LDO dataExcellent (sensitive) for patients≥65 yr with preceding claims
CMS Form 2728 universally collected but with limitations on variables included/accuracy
  • Database sources are MarketScan and inVentiv Health Clinical (formerly Ingenix i3) databases. All deaths are recorded with CMS Form 2746. LDO, large dialysis organization; CMS, Center for Medicaid and Medicare Services; EGHP, Employer Group Health Plan; DOPPS, Dialysis Outcomes, Practice and Patterns Survey; USRDS, US Renal Data System.