The effect of using NHS number as the unique identifier for patients who self-harm: AA multi-centre descriptive study

Research output: Contribution to journalArticle

  • External authors:
  • Jayne Cooper
  • Elizabeth Murphy
  • Helen Bergen
  • Deborah Casey
  • Keith Hawton
  • David Owens
  • Rachael Lilley
  • Rachael Noble


Background: Processing personal data for research purposes and the requirement of anonymity has been the subject of recent debate. We aimed to determine the proportion of individuals who present to emergency departments with non-fatal suicidal behavior where an NHS number has been successfully traced and to investigate the characteristics of patients associated with non-capture. Method: This was a descriptive study of people attending after self-harm using allocation of NHS numbers as main outcome measurement. Data from the Multicentre Monitoring of Self-Harm Project from 3 centres in England were used to identify consecutive patients (N = 3000) who were treated in six emergency departments in Oxford, Manchester and Leeds in 2004 and 2005 following self-harm. Results: NHS number was available between 55-73% of individuals across centres. Characteristics associated with non-recording of NHS number in more than one centre included those from ethnic minority groups (Oxford: chi-squared statistic = 13.6, df = 3, p = 0.004; Manchester: chi-squared statistic = 13.6, df = 3, p ≤0.001) and the homeless or living in a hostel or other institution (Oxford: chi-squared statistic = 40.9, df = 7, p =

Bibliographical metadata

Original languageEnglish
Article number16
JournalClinical Practice and Epidemiology in Mental Health
Publication statusPublished - 21 Sep 2007