Purpose: To examine the usefulness of three types of benchmarking for inter
preting patient outcome data.
Design: This study was part of a multiyear, multihospital longitudinal surv
ey of 10 patient outcomes. The patient outcome used for this methodologic p
resentation was central line infections (CLI). The sample included eight ho
spitals in an integrated healthcare system, with a range in size from 144 t
o 861 beds. The unit of analysis for CLI was the number of line days, with
the CLI rate defined as the number of infections per 1,000 patient-line day
s per month.
Methods: Data on each outcome were collected at the unit level according to
standardized protocols. Results were submitted via standardized electronic
forms to a central data management center. Data for this presentation were
analyzed using a Bayesian hierarchical Poisson model. Results are presente
d for each hospital and the system as a whole.
Findings: In comparison to published benchmarks, hospital performances were
mixed with regard to CLL Five of the 8 hospitals exceeded 2.2 infections p
er 1,000 patient-line days. When benchmarks were established for each hospi
tal using 95% credible intervals, hospitals did reasonably well with only i
solated months reaching or going beyond the benchmark limits. When the enti
re system was used to establish benchmarks with the 95% credible intervals,
the hospitals that reached or exceeded the benchmark limits remained the s
ame, but some hospitals bad CLI rates more frequently in the upper 50% of t
he benchmarking limits.
Conclusions: Benchmarking of quality indicators can be accomplished in a va
riety of ways as a means to quantify patient care and identify areas needin
g attention and improvement. Hospital-specific and system-wide benchmarks p
rovide relevant feedback for improving performance at individual hospitals.