title: Frequency of blood glucose testing in well educated patients with diabetes mellitus type 1: how often is enough?
abstract: OBJECTIVE
  Self-monitored blood glucose (SMBG) and knowledge of insulin requirements are pivotal for good metabolic control in patients with diabetes mellitus type 1. However, the SMBG-frequency needed for optimal glycaemic control especially in well educated patients is unclear.
  
  
  METHODS
  In patients with type 1 diabetes treated with flexible intensified insulin therapy, we evaluated HbA1c values and the directly preceding computerised SMBG-frequencies over a 12 months period. To estimate the association between HbA1c and SMBG-frequency, we fitted a piecewise linear spline model with a change in slope at 4 SMBGs per day which is the recommended minimal SMBG-frequency at our institution.
  
  
  RESULTS
  A total of 150 patients were available for analysis, with a median baseline HbA1c of 7.1% (interquartile range 6.6, 7.8). In the multivariable analysis (adjusted for gender and psychological problems), each additional SMBG measurement was associated with an estimated difference in HbA1c of -0.19% (95% confidence interval (CI) -0.42, 0.05) for ≤4 SMBGs per day and of -0.02% (95% CI -0.10, 0.06) for >4 SMBGs per day.
  
  
  CONCLUSIONS
  Good diabetes control can be achieved in routine diabetes care with flexible intensified insulin therapy based on continuing patients' education and with a minimum of 4 SMBGs per day.
authors.affiliation: Division of Endocrinology Diabetes and Metabolism, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland.
authors.forename: Anna Elisabeth
authors.initials: AE
authors.lastname: Minder
authors.affiliation: Division of Endocrinology Diabetes and Metabolism, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland.
authors.forename: Dominique
authors.initials: D
authors.lastname: Albrecht
authors.affiliation: Basel Institute for Clinical Epidemiology and Biostatistics, University Hospital Basel, Hebelstrasse 10, 4031 Basel, Switzerland; Clinical Trial Unit, University Hospital Basel, Schanzenstrasse 55, 4031 Basel, Switzerland.
authors.forename: Juliane
authors.initials: J
authors.lastname: Schäfer
authors.affiliation: Division of Endocrinology Diabetes and Metabolism, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland. Electronic address: Henryk.zulewski@unibas.ch.
authors.forename: Henryk
authors.initials: H
authors.lastname: Zulewski
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001786:Blood Glucose / Q000378:metabolism*; D015190:Blood Glucose Self-Monitoring / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data*; D010353:Patient Education as Topic; D011379:Prognosis; D012189:Retrospective Studies; D012648:Self Care / Q000523:psychology*
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human