title: Prevalence of working smoke alarms in local authority inner city housing: randomised controlled trial.
abstract: OBJECTIVE
  To identify which type of smoke alarm is most likely to remain working in local authority inner city housing, and to identify an alarm tolerated in households with smokers.
  
  
  METHODS
  Randomised controlled trial.
  
  
  METHODS
  Two local authority housing estates in inner London.
  
  
  METHODS
  2145 households.
  
  
  METHODS
  Installation of one of five types of smoke alarm (ionisation sensor with a zinc battery; ionisation sensor with a zinc battery and pause button; ionisation sensor with a lithium battery and pause button; optical sensor with a lithium battery; or optical sensor with a zinc battery).
  
  
  METHODS
  Percentage of homes with any working alarm and percentage in which the alarm installed for this study was working after 15 months.
  
  
  RESULTS
  54.4% (1166/2145) of all households and 45.9% (465/1012) of households occupied by smokers had a working smoke alarm. Ionisation sensor, lithium battery, and there being a smoker in the household were independently associated with whether an alarm was working (adjusted odds ratios 2.24 (95% confidence interval 1.75 to 2.87), 2.20 (1.77 to 2.75), and 0.62 (0.52 to 0.74)). The most common reasons for non-function were missing battery (19%), missing alarm (17%), and battery disconnected (4%).
  
  
  CONCLUSIONS
  Nearly half of the alarms installed were not working when tested 15 months later. Type of alarm and power source are important determinants of whether a household had a working alarm.
authors.affiliation: Public Health Intervention Research Unit, London School of Hygiene and Tropical Medicine, London WC1B 3DP.
authors.forename: Diane
authors.initials: D
authors.lastname: Rowland
authors.forename: Carolyn
authors.initials: C
authors.lastname: DiGuiseppi
authors.forename: Ian
authors.initials: I
authors.lastname: Roberts
authors.forename: Katherine
authors.initials: K
authors.lastname: Curtis
authors.forename: Helen
authors.initials: H
authors.lastname: Roberts
authors.forename: Laura
authors.initials: L
authors.lastname: Ginnelly
authors.forename: Mark
authors.initials: M
authors.lastname: Sculpher
authors.forename: Angela
authors.initials: A
authors.lastname: Wade
mesh_terms: D011211:Electric Power Supplies; D004868:Equipment Failure; D005191:Family Characteristics; D006798:Housing / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D008131:London / Q000453:epidemiology; D015999:Multivariate Analysis; D016017:Odds Ratio; D011482:Protective Devices / Q000706:statistics & numerical data*; D014504:Urban Health