title: Point-of-care blood glucose measurement errors overestimate hypoglycaemia rates in critically ill patients.
abstract: BACKGROUND
  Hypoglycaemia is associated with morbidity and mortality in critically ill patients, and many hospitals have programmes to minimize hypoglycaemia rates. Recent studies have established the hypoglycaemic patient-day as a key metric and have published benchmark inpatient hypoglycaemia rates on the basis of point-of-care blood glucose data even though these values are prone to measurement errors.
  
  
  METHODS
  A retrospective, cohort study including all patients admitted to Harborview Medical Center Intensive Care Units (ICUs) during 2010 and 2011 was conducted to evaluate a quality improvement programme to reduce inappropriate documentation of point-of-care blood glucose measurement errors. Laboratory Medicine point-of-care blood glucose data and patient charts were reviewed to evaluate all episodes of hypoglycaemia.
  
  
  RESULTS
  A quality improvement intervention decreased measurement errors from 31% of hypoglycaemic (<70 mg/dL) patient-days in 2010 to 14% in 2011 (p < 0.001) and decreased the observed hypoglycaemia rate from 4.3% of ICU patient-days to 3.4% (p < 0.001). Hypoglycaemic events were frequently recurrent or prolonged (~40%), and these events are not identified by the hypoglycaemic patient-day metric, which also may be confounded by a large number of very low risk or minimally monitored patient-days.
  
  
  CONCLUSIONS
  Documentation of point-of-care blood glucose measurement errors likely overestimates ICU hypoglycaemia rates and can be reduced by a quality improvement effort. The currently used hypoglycaemic patient-day metric does not evaluate recurrent or prolonged events that may be more likely to cause patient harm. The monitored patient-day as currently defined may not be the optimal denominator to determine inpatient hypoglycaemic risk.
authors.affiliation: Department of Medicine, Division of Metabolism, Endocrinology and Nutrition, Diabetes and Obesity Center of Excellence, University of Washington, Seattle, WA, USA.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Nya-Ngatchou
authors.forename: Dawn
authors.initials: D
authors.lastname: Corl
authors.forename: Susan
authors.initials: S
authors.lastname: Onstad
authors.forename: Tom
authors.initials: T
authors.lastname: Yin
authors.forename: Tracy
authors.initials: T
authors.lastname: Tylee
authors.forename: Louise
authors.initials: L
authors.lastname: Suhr
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Thompson
authors.forename: Brent E
authors.initials: BE
authors.lastname: Wisse
mesh_terms: D000046:Academic Medical Centers; D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D015331:Cohort Studies; D003422:Critical Care; D003951:Diagnostic Errors / Q000517:prevention & control*; D016903:Drug Monitoring; D057286:Electronic Health Records; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000009:adverse effects; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000009:adverse effects; D007362:Intensive Care Units; D019095:Point-of-Care Systems; D015397:Program Evaluation; D058996:Quality Improvement; D012008:Recurrence; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012306:Risk; D014861:Washington / Q000453:epidemiology
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin
keywords: critical illness; diabetes; glycaemic control; insulin; quality improvement