title: Risk factors for excessive benzodiazepine use in a working age population: a nationwide 5-year survey in Norway.
abstract: OBJECTIVE
  To identify risk factors for becoming an excessive user over time.
  
  
  METHODS
  Prescription database study over five years.
  
  
  METHODS
  Norwegians between 30 and 60 years with a first dispensation of a benzodiazepine during 2006, encompassing 23 227 individuals. A Cox hazard regression model was defined, initially stratifying on gender, age, county, previous relevant drug dispensations, household income, education level, and vocational rehabilitation support.
  
  
  METHODS
  The time from the first redemption until excessive use was defined as using more than two DDDs per day on average within a three-month period.
  
  
  RESULTS
  Women's risk was lower than men's for excessive use (HR = 0.42, CI 0.35-0.51). Initial oxazepam, alprazolam, or nitrazepam/flunitrazepam use indicated higher risk compared with diazepam (HR = 1.51, CI 1.24-1.85, HR = 2.75, CI 1.54-4.91, HR = 1.67, CI 1.29-2.16). Previous antidepressants or lithium, antipsychotics or opioids, anti-alcohol and smoke cessation treatment indicated a higher risk compared with no such use (HR = 1.4, CI 1.16-1.69, HR = 1.92, CI 1.54-2.4, and HR = 2.88, CI 2-4.15). Higher education and average or high household income were associated with a low risk compared with low education and income (HR = 0.68, CI 0.57-0.81, HR = 0.58, CI 0.46-0.73, and HR = 0.37, CI 0.26-0.54). Working in the private or public sector was associated with a low risk compared with no registered work (HR = 0.53, CI 0.4-0.71 and HR = 0.57, CI 0.45-0.74).
  
  
  CONCLUSIONS
  The prevalence of excessive use over a five-year observation period was 2.34%. Risk factors were indications of psychiatric illness, first benzodiazepine choice, low income, and education. Excessive users were also characterized by a more severe disease, indicated by having prescription fulfilments by a psychiatrist and by switching benzodiazepines. Key points Guidelines state that benzodiazepines should be used for a short time and excessive use indicates drug dependency. Of all new benzodiazepine users 2.34% became excessive users, defined as consuming above two defined daily doses (DDDs) per day on average over three months, within a five-year period. Previous use of other psychotropic drugs, opioids and anti-alcohol and smoke cessation drugs, first benzodiazepine prescribed, low household income, and low education were risk factors for excessive use. Excessive users were characterized by switching benzodiazepines and having prescription fulfilments by a psychiatrist suggesting a more severe disease.
authors.affiliation: a The Norwegian Computing Center , Oslo , Norway ;
authors.forename: Ingunn
authors.initials: I
authors.lastname: Fride Tvete
authors.affiliation: b Department of General Practice , Institute of Health and Society, University of Oslo , Blindern , Oslo , Norway ;
authors.forename: Trine
authors.initials: T
authors.lastname: Bjørner
authors.affiliation: c Department of Pharmacology , Institute of Clinical Medicine, University of Oslo , Blindern Oslo , Norway.
authors.forename: Tor
authors.initials: T
authors.lastname: Skomedal
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000008:administration & dosage*; D001569:Benzodiazepines / Q000008:administration & dosage*; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D063487:Prescription Drug Misuse / Q000706:statistics & numerical data*; D015995:Prevalence; D011619:Psychotropic Drugs / Q000008:administration & dosage; D012044:Regression Analysis; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D000928:Antidepressive Agents; D011619:Psychotropic Drugs; D001569:Benzodiazepines
keywords: Benzodiazepines; Cox regression; Norway; excessive use; general practice