Instruments for self-monitoring of blood glucose: comparisons of testing quality achieved by patients and a technician.
BACKGROUND
Instruments for self-monitoring of blood glucose (SMBG) are increasingly used by patients with diabetes. The analytical quality of meters in routine use is poorly characterized.


METHODS
We compared SMBG performance achieved by patients and by a medical laboratory technician. Imprecision was calculated from duplicate measurements, and deviation as the difference between the first measurement and the mean of duplicate laboratory-method results (calibrated with NIST material). Analytical quality for five groups of SMBG instruments was compared with quality specifications for BG measurements. All participants completed a questionnaire assessing both SMBG training and use of the meters.


RESULTS
We recruited 159 SMBG users from a hospital outpatient clinic and 263 others from 65 randomly selected general practices (total of 422). Most (two thirds) used insulin. CVs for the five meter types were 7%, 11%, 18%, 18%, and 20% in the hands of patients and 2.5-5.9% for the technician. For three of five meter types, patients' BG measurements had larger deviations from the laboratory results than did the technician's results. The technician's performance could not predict the patients'. No instrument when used by patients (but two operated by the technician) met published quality specifications. The analytical quality of patients' results was not related to whether they had chosen the instruments on advice from healthcare personnel (one-third of patients), were only self-educated in SMBG (50%), or performed SMBG fewer than seven times/week (62%).


CONCLUSIONS
The analytical quality of SMBG among patients was poorer than, and could not be predicted from, the performance of the meters in the hands of a technician. We suggest that new instruments be tested in the hands of patients who are trained on meter use in a routine way.
Skeie
Svein
S
NOKLUS, Norwegian Center for Quality Improvement of Primary Care Laboratories, Division of General Practice, Department of Public Health and Primary Care, Ulriksdal 8c, University of Bergen, N-5009 Bergen, Norway. svskeie@online.no
Thue
Geir
G
Nerhus
Kari
K
Sandberg
Sverre
S
D000328:Adult; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation*; D003920:Diabetes Mellitus / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D017056:Medical Laboratory Personnel; D008875:Middle Aged; D010361:Patients; D011786:Quality Control; D011795:Surveys and Questionnaires