title: Fainting and hemolysis during blood sampling in youngsters: prevalence study.
abstract: OBJECTIVE
  To assess the incidence of fainting and hemolysis in taking blood samples from adolescents in a school setting.
  
  
  METHODS
  A cross-sectional school-based survey. All blood samples and data were collected during September and October 2005.
  
  
  METHODS
  A community sample of 869 youngsters attending third grade secondary education in 14 secondary schools in the Flemish province of Antwerp, Belgium (mean age: 17.3 years, +/-1.2 years).
  
  
  METHODS
  Fasting blood samples were obtained on-site for measurement of levels of glucose, high density lipoprotein cholesterol and triglycerides. The incidence of fainting and hemolysis was assessed.
  
  
  RESULTS
  In 60% of the total sample a blood sample was taken, 15% refused. In the remaining 25%, taking a blood sample was not possible due to problems in drawing blood from the vein (4%) or not fasting (21%). The incidence of fainting was 2.5%. Hemolysis occurred in 2.4% of the blood samples.
  
  
  CONCLUSIONS
  When taking blood samples in this age group, there seems to be a great willingness to participate. Precaution should be taken though when taking blood samples in youngsters. In this study, about 1 in 40 students fainted. When blood samples are taken on-site and transported to a laboratory, an incidence of hemolysis of 2.4% should be taken into account.
authors.affiliation: University College of Antwerp, Department of Health Sciences-Nursing and Physiotherapy, Antwerp, Belgium. d.vissers@ha.be
authors.forename: Dirk
authors.initials: D
authors.lastname: Vissers
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Matthyssen
authors.forename: Steven
authors.initials: S
authors.lastname: Truijen
authors.forename: Sabrina
authors.initials: S
authors.lastname: Blommaert
authors.forename: Katrijn
authors.initials: K
authors.lastname: Van De Velde
authors.forename: Luc
authors.initials: L
authors.lastname: Van Gaal
mesh_terms: D000293:Adolescent; D001530:Belgium / Q000453:epidemiology; D015992:Body Mass Index; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D005215:Fasting; D005260:Female; D006301:Health Services Needs and Demand; D006306:Health Surveys; D006461:Hemolysis; D006801:Humans; D015994:Incidence; D008019:Life Style; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D015403:Nursing Evaluation Research; D009765:Obesity / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D010353:Patient Education as Topic; D018962:Phlebotomy / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D011159:Population Surveillance; D012307:Risk Factors; D013575:Syncope / Q000453:epidemiology* / Q000209:etiology* / Q000517:prevention & control