title: Effect on smoking quit rate of telling patients their lung age: the Step2quit randomised controlled trial.
abstract: OBJECTIVE
  To evaluate the impact of telling patients their estimated spirometric lung age as an incentive to quit smoking.
  
  
  METHODS
  Randomised controlled trial.
  
  
  METHODS
  Five general practices in Hertfordshire, England.
  
  
  METHODS
  561 current smokers aged over 35.
  
  
  METHODS
  All participants were offered spirometric assessment of lung function. Participants in intervention group received their results in terms of "lung age" (the age of the average healthy individual who would perform similar to them on spirometry). Those in the control group received a raw figure for forced expiratory volume at one second (FEV1). Both groups were advised to quit and offered referral to local NHS smoking cessation services.
  
  
  METHODS
  The primary outcome measure was verified cessation of smoking by salivary cotinine testing 12 months after recruitment. Secondary outcomes were reported changes in daily consumption of cigarettes and identification of new diagnoses of chronic obstructive lung disease.
  
  
  RESULTS
  Follow-up was 89%. Independently verified quit rates at 12 months in the intervention and control groups, respectively, were 13.6% and 6.4% (difference 7.2%, P=0.005, 95% confidence interval 2.2% to 12.1%; number needed to treat 14). People with worse spirometric lung age were no more likely to have quit than those with normal lung age in either group. Cost per successful quitter was estimated at 280 pounds sterling (366 euros, $556). A new diagnosis of obstructive lung disease was made in 17% in the intervention group and 14% in the control group; a total of 16% (89/561) of participants.
  
  
  CONCLUSIONS
  Telling smokers their lung age significantly improves the likelihood of them quitting smoking, but the mechanism by which this intervention achieves its effect is unclear.
  
  
  BACKGROUND
  National Research Register N0096173751.
authors.affiliation: The Limes Surgery, Hoddesdon, Hertfordshire EN11 8EP. Parkesko@hotmail.co.uk
authors.forename: Gary
authors.initials: G
authors.lastname: Parkes
authors.forename: Trisha
authors.initials: T
authors.lastname: Greenhalgh
authors.forename: Mark
authors.initials: M
authors.lastname: Griffin
authors.forename: Richard
authors.initials: R
authors.lastname: Dent
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008171:Lung Diseases / Q000503:physiopathology*; D008875:Middle Aged; D011379:Prognosis; D012907:Smoking / Q000503:physiopathology* / Q000523:psychology; D016540:Smoking Cessation / Q000523:psychology / Q000706:statistics & numerical data*; D013147:Spirometry; D014797:Vital Capacity / Q000502:physiology