title: Effect of ambient temperature on analytical performance of self-monitoring blood glucose systems.
abstract: BACKGROUND
  The analytical quality of self-monitoring of blood glucose (SMBG) can be affected by environmental conditions such as temperature. The objective of this study was to determine the influence of (1) a shift in the ambient temperature immediately before measurement and (2) taking measurements in the lower and upper part of the operating temperature range.
  
  
  METHODS
  Nine different SMBG systems on the Norwegian market were tested with heparinized venous blood (4.8 and 19.0 mmol/L). To test the shift in ambient temperature effect, the glucometer and strips were equilibrated for 1 h at 5°C or 1 h at 30°C before the meter and strips were moved to room temperature, and measurements were performed after 0, 5, 10, 15, and 30 min. To test the lower and upper temperature range, measurements were performed at 10°C and at 39°C after 1 h for temperature equilibration of the glucometer and strips. All these measurements were compared with measurements performed simultaneously on a meter and strips kept at room temperature the whole time.
  
  
  RESULTS
  Six of nine SMBG systems overestimated and/or underestimated the results by more than 5% after moving meters and strips from 5°C or 30°C to room temperature immediately before the measurements. Two systems underestimated the results at 10°C. One system overestimated and another underestimated the results by more than 5% at 39°C.
  
  
  CONCLUSIONS
  The effect on analytical performance was most pronounced after a rapid shift in the ambient temperature. Therefore patients need to wait at least 15 min for temperature equilibration of affected meters and strips before measuring blood glucose.
authors.affiliation: Norwegian Centre for Quality Improvement of Primary Care Laboratories, Section for General Practice, Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway. kari.nerhus@noklus.no
authors.forename: Kari
authors.initials: K
authors.lastname: Nerhus
authors.forename: Pål
authors.initials: P
authors.lastname: Rustad
authors.forename: Sverre
authors.initials: S
authors.lastname: Sandberg
mesh_terms: D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation*; D006801:Humans; D008422:Materials Testing; D009664:Norway; D011934:Reagent Strips / Q000737:chemistry; D015203:Reproducibility of Results; D013696:Temperature; D013997:Time Factors
chemical_list: D011934:Reagent Strips