Correlation Between Methods to Calculate Denominators for Dialysis Event Surveillance Using Electronic Health Record Data, Tennessee, 2012
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.
R. Belflower, None
M. Kanago, None
M. A. Kainer, None
N. Thompson, None
C. Lovell, None
P. Patel, None
M. Wise, None