title: Adverse events recorded in English primary care: observational study using the General Practice Research Database.
abstract: BACKGROUND
  More accurate and recent estimates of adverse events in primary care are necessary to assign resources for improvement of patient safety, while predictors must be identified to ameliorate patient risk.
  
  
  OBJECTIVE
  To determine the incidence of recorded iatrogenic harm in general practice and identify risk factors for these adverse events.
  
  
  METHODS
  Cross-sectional sample of 74,763 patients at 457 English general practices between 1 January 1999 and 31 December 2008, obtained from the General Practice Research Database.
  
  
  METHODS
  Patient age at study entry, sex, ethnicity, deprivation, practice region, duration registered at practice, continuity of care, comorbidities, and health service use were extracted from the data. Adverse events were defined by Read Codes for complications of care (Chapters S, T, and U). Crude and adjusted analyses were performed by Poisson regression, using generalised estimating equations.
  
  
  RESULTS
  The incidence was 6.0 adverse events per 1000 person-years (95% confidence interval [CI] = 5.74 to 6.27), equivalent to eight adverse events per 10,000 consultations (n = 2,540,877). After adjustment, patients aged 65-84 years (risk ratio [RR] = 5.62, 95% CI = 4.58 to 6.91; P<0.001), with the most consultations (RR = 2.14, 95% CI = 1.60 to 2.86; P<0.001), five or more emergency admissions (RR = 2.08, 95% CI = 1.66 to 2.60; P<0.001), or the most diseases according to expanded diagnosis clusters (RR = 8.46, 95% CI = 5.68 to 12.6; P<0.001) were at greater risk of adverse events. Patients registered at their practice for the longest periods of time were less at risk of an adverse event (RR = 0.40, 95% CI = 0.35 to 0.47; P<0.001).
  
  
  CONCLUSIONS
  The low incidence of recorded adverse events is comparable with other studies. Temporal sequencing of risk factors and case ascertainment would benefit from data triangulation. Future studies may explore whether first adverse events predict future incidents.
authors: Dr Foster Unit at Imperial, Department of Primary Care and Public Health, Imperial College London, London. c.tsang@imperial.ac.uk
authors: Carmen
authors: C
authors: Tsang
authors: Alex
authors: A
authors: Bottle
authors: Azeem
authors: A
authors: Majeed
authors: Paul
authors: P
authors: Aylin
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004739:England / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D058006:General Practice / Q000706:statistics & numerical data*; D006801:Humans; D007049:Iatrogenic Disease / Q000453:epidemiology*; D007223:Infant; D008297:Male; D019300:Medical Errors / Q000706:statistics & numerical data*; D008875:Middle Aged; D017678:Sex Distribution; D055815:Young Adult
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