title: Methodology for assessing the prevalence of angina in primary care using practice based information in northern England.
abstract: OBJECTIVE
  The study aimed to consider the value of nitrate prescriptions issued by general practices as an indicator of coronary heart disease and to compare this with the use of coronary heart disease registers.
  
  
  METHODS
  The study was a cross sectional survey. A self completed questionnaire was used by general practices to indicate an age and gender breakdown of the total practice population, the number of patients taking nitrates, and details of patients recorded on a coronary heart disease register.
  
  
  METHODS
  All 48 general practices registered with Wakefield Family Health Services Authority were sent a questionnaire.
  
  
  RESULTS
  The prevalence of angina in the sample population of 164796 was 3.1%. The prevalence of angina as assessed by coronary heart disease registers was significantly higher at 4.3%.
  
  
  CONCLUSIONS
  Using questionnaires to assess how many patients are taking nitrates and therefore have angina may provide a quick, "snapshot" view of the prevalence of angina but the methodology is not a robust epidemiological tool. It is likely to provide errors in estimates of true prevalence and risks some under estimation when compared with coronary heart disease registers.
authors.affiliation: Cancer Research Centre of Hawaii, University of Hawaii at Manoa, Honolulu 96813, USA.
authors.forename: A
authors.initials: A
authors.lastname: Bottomley
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000188:drug therapy / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D004739:England / Q000453:epidemiology; D004812:Epidemiologic Methods; D005194:Family Practice / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000627:therapeutic use; D015995:Prevalence; D012042:Registries
chemical_list: D009566:Nitrates