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Kidney Week

Abstract: TH-OR096

Short-Term Gaps in Insurance Lead to Long-Term Disparities in Peritoneal Dialysis Use

Session Information

  • Home Dialysis
    November 07, 2019 | Location: 143, Walter E. Washington Convention Center
    Abstract Time: 06:06 PM - 06:18 PM

Category: Dialysis

  • 703 Dialysis: Peritoneal Dialysis


  • Lin, Eugene, Keck School of Medicine of USC, Los Angeles, California, United States
  • Chertow, Glenn Matthew, Stanford University School of Medicine, Palo Alto, California, United States
  • Bhattacharya, Jay, Stanford University, Stanford, California, United States
  • Lakdawalla, Darius, University of Southern California, Los Angeles, California, United States

Peritoneal dialysis (PD) offers improved quality of life over hemodialysis without compromising health outcomes. Uninsured patients do not become Medicare eligible until the first day of the fourth month of treatment. Using a quasi-experimental method, we studied whether short-term gaps in insurance were associated with long-term disparities in PD use.


Because Medicare eligibility starts on the first day of the fourth month of dialysis, patients starting dialysis at the end of the month have a shorter Medicare waiting period than patients starting dialysis at the beginning of the month. After identifying uninsured adults starting dialysis between 1/1/2006 and 12/31/2014 in the United States from a national registry, we studied whether starting dialysis at the end of the month was associated with higher PD use at day 360 than starting at the beginning of the month. Using two-stage least squares regression, we investigated whether gaps in insurance were associated with long-term disparities in PD use.


The distribution of dialysis start day was distributed randomly (one-sample Kolmogorov-Smirnov, p>0.05). Patients starting dialysis in the first half of the month had a 10.7% (95% CI: 10.2-11.1%) probability of using PD at 360 days, while those starting in the last half of the month had an 11.8% (95% CI: 11.3-12.1%) probability (difference: 1.1% [0.5-1.7%]). Patients starting dialysis on the 31st had a 2.3% (95% CI: 1.1-3.5%) higher probability of PD use at day 360 than those starting on the 1st. Our second-stage regression showed that every 10 day gap without insurance was associated with a 1.0% (95% CI: 0.5-1.5%) absolute decrease in PD use at day 360. We projected that eliminating the Medicare waiting period entirely could increase the probability of long-term PD use in patients without insurance, from 11.2% to 19.8% (95% CI: 16.3, 23.3%).


Patients starting dialysis later in the month have shorter Medicare waiting periods and are more likely to use PD long-term. We exploited this difference to show that that longer periods of time without insurance lead to persistent decreases in PD use. Extending Medicare coverage to the first three months of dialysis or earlier could substantially improve PD penetration.


  • NIDDK Support