Cost-effectiveness of a lung health intervention in US smokers

A study (Step2quit, Parkes et al. BMJ 2008) of current smokers randomized to assessment and communication of “lung age” vs no assessment found 13.6% of intervention vs 6.4% of controls smoke-free at 1 year. Our objective was to expand on Step2quit using a model to estimate the impact of a lung health intervention (LHI) consisting of spirometry and lung age assessment on lifetime effects of COPD diagnosis, progression, costs, and cost per quality-adjusted life-year (QALY) gained vs usual care (UC). The model was estimated from US population surveys and published studies. Target population was US smokers aged ≥35 years, stratified by COPD severity (GOLD stage) and diagnosis receiving LHI vs UC at a routine office visit. Post-visit COPD diagnosis and smoking cessation differ by receipt of LHI. Depending on GOLD stage, diagnosed patients may receive SABA, anticholinergics (AC), LABA+ICS, or AC+SABA. Costs and outcomes were modeled with Markov health states defined by smoking status, GOLD Stage and diagnosis. Transition to more severe GOLD stage depends on treatment received and smoking status. Lifetime costs (in $2009) and outcomes were discounted at 3%/year. Results show that LHI leads to more lifetime diagnosis (72% LHI vs 51% UC) and less progression to severe/very severe COPD (10.1% LHI vs 12.4% UC). Lifetime per-person COPD costs are $52,789 for LHI vs $51,182 for UC, with higher LHI costs of intervention ($57) and treatment ($3,731) partially offset by lower COPD management costs (-$2,181). LHI provides additional QALYS at $10,064/QALY gained. Using conventional willingness-to-pay threshold values, LHI is a cost-effective intervention in COPD.