Program Schedule

Correlation Between Methods to Calculate Denominators for Dialysis Event Surveillance Using Electronic Health Record Data, Tennessee, 2012

Session: Poster Abstract Session: HAI Surveillance and Public Reporting
Friday, October 10, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
Background: To reduce the burden of manual denominator data collection, the National Healthcare Safety Network (NHSN) uses number of patients dialyzed at a clinic during the first two working days of a reporting month as a proxy measure for the total number of patient-days at-risk during that month. Some stakeholders have expressed concerns that these methods may not reflect patient volume as well as proxies based on other time intervals during a reporting month. We compared various denominator measures using electronically obtained denominator data from 13 outpatient dialysis clinics belonging to the same organization.

Methods: All 13 clinics used a uniform electronic health record (EHR) system.  From the EHR, we captured all patient dialysis sessions at each clinic between January and October 2012 to calculate: the monthly total denominator (i.e., total number of patients dialyzed at the clinic during all days of the month), and three denominator proxies (i.e., using the first two, last two, and two randomly selected consecutive working days of the month). Linear correlation between the NHSN proxy method and the other denominator measures was evaluated.

Results: During the study period, the EHR included 94,953 patient-months of denominator data from 13 clinics (range: 2,272 – 10,108 per facility). A strong correlation was observed between monthly total denominator and NHSN denominator proxy (Pearson Correlation Coefficient [PCC]: 0.988, p<0.0001), and between the NHSN denominator proxy and the other proxy methods (PCC: 0.988–0.991).  Correlation between NHSN and total denominator with PCC> 0.3 was found in 11 of the 13 clinics. Denominators stratified by vascular access types (i.e., central line, arteriovenous fistula and arteriovenous graft) also showed strong correlation between the denominator measures.

Conclusion: Analysis of EHR-generated denominator data suggests use of the NHSN denominator based on 2 consecutive working days at the start of the month was a satisfactory proxy for the total monthly denominator in most of these dialysis clinics.

Duc Nguyen, MD1, Vlad Ladik2, Ruth Belflower, RN, MPH3, Meredith Kanago, MSPH4, Marion a. Kainer, MBBS, MPH4, Nicola Thompson1, Chris Lovell2, Priti Patel1 and Matthew Wise, PhD3, (1)Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, GA, (2)Dialysis Clinic, Inc., Nashville, TN, (3)Centers for Disease Control and Prevention, Atlanta, GA, (4)Tennessee Department of Health, Nashville, TN


D. Nguyen, None

V. Ladik, None

R. Belflower, None

M. Kanago, None

M. A. Kainer, None

N. Thompson, None

C. Lovell, None

P. Patel, None

M. Wise, None

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