Interinstitutional comparison of bedside blood glucose monitoring program characteristics, accuracy performance, and quality control documentation: a College of American Pathologists Q-Probes study of bedside blood glucose monitoring performed in 226 small hospitals.

OBJECTIVES

To assess the accuracy of bedside blood glucose monitoring (BGM) in small hospitals, to assess the compliance with which hospital workers performing bedside BGM adhere to quality control (QC) procedures, and to identify those practice characteristics in small hospitals that are associated with better BGM accuracy and with better performance of BGM QC.

DESIGN

Over a 1-month period in 1996, voluntary participants in the College of American Pathologists Q-Probes laboratory quality improvement program prospectively compared glucose results of 30 split samples run on BGM instruments with those performed on laboratory glucose analyzers, collected quality control data on up to five inpatient BGM instruments, and completed questionnaires profiling BGM practice characteristics in their institutions.

SETTING AND PARTICIPANTS

Two hundred twenty-six hospitals with 200 or fewer occupied beds.

MAIN OUTCOME MEASURES

The percentages of glucose determinations performed on BGM instruments differing by more than 10%, 15%, and 20% from those split-sample results performed on laboratory glucose analyzers; the percent of BGM QC determinations required by institutions' BGM QC programs that BGM operators actually performed; and the percent of patient values reported when BGM QC was documented to be out of range and uncorrected, or reported when BGM QC was not performed at all.

RESULTS

Of 6095 split-specimen glucose results that participants simultaneously performed on BGM instruments and on laboratory glucose analyzers, 45.6% differed from each other by more than 10%, approximately 25% differed from each other by more than 15%, and almost 14% differed from each other by more than 20%. Of 216 laboratories that performed at least 30 QC events during the study period, slightly over a third completed 100% of their required QC determinations, and 10% completed, at most, 77% of their required BGM QC determinations. Of 115,973 BGM determinations that participants reported on hospitalized patients, 3.3% were reported when QC was either out of range or when there was no documentation that QC had been performed at all. Better accuracy and/or better QC performance was associated with laboratory personnel rather than nursing personnel both supervising institutions' BGM QC programs and running institutions' daily routine BGM QC; with BGM operators both routinely running three, rather than two, levels of QC analytes; with BGM operators regularly comparing BGM results with laboratory analyzer glucose results; and with institutions participating in external proficiency programs. Institutions that completed all required BGM QC tasks tended to perform better on the BGM accuracy study than did those institutions that completed, at most, 77% of their required QC.

CONCLUSIONS

We found the rates of BGM accuracy and of QC performance adequacy achieved in small hospitals to be similar to those determined in previous Q-Probes studies conducted in large institutions. A significant amount of institutional bedside testing does not meet current standards for accuracy or for quality control. Some institutions may improve their accuracy and/or QC performances by having laboratory personnel intimately involved in their institution's BGM QC program, by routinely comparing BGM results with those performed using glucose analyzers in the clinical laboratory, by routinely running three rather than two glucose QC control levels, by participating in external proficiency programs, and by strictly adhering to institutional QC protocols.