Cost-effectiveness of a low-dose computed tomography screening programme for lung cancer in New Zealand

The cost-effectiveness of low-dose computed tomography (LDCT) screening for lung cancer is uncertain. This study estimated the health gains, costs (net health system, and including 'unrelated') and cost-effectiveness of biennial LDCT screening among 55-74 years olds with a smoking history of at least 30 pack years, and (if a former smoker) having quit within last 15 years, in New Zealand.

We used a macrosimulation stage shift model with New Zealand-specific lung cancer incidence rates and intervention parameters from the National Lung Screening Trial, a health system perspective, and a lifetime horizon for quality-adjusted life-years (QALYs) and costs discounted at 3% per annum. We also examined heterogeneity by gender, ethnicity (Māori (indigenous population) versus non-Māori), age and smoking status.

We estimated 0.067 QALYs gained (95 % uncertainty interval (UI) 0.044 to 0.095) per eligible participant, at a cost of US$2843 ($2067-3797; 2011 $US). The overall incremental cost effectiveness ratio (ICER) was US$44,000 per QALY gained (95 % UI US$27,000 to US$70,000). The ICER was substantially lower for Māori, at US$26,000 per QALY gained (95 % UI US$17,000 to US$39,000). The cost-effectiveness varied by socio-demographics, from US$21,000 for 70-74 year old Māori females to US$60,000 for 55-59 year old non-Māori males. The two scenarios that lowered the ICER the most were halving the screening costs (ICER = US$33,000 per QALY), and improving the sensitivity (from 93.8% to 98%) and specificity (from 73.4% to 95%) of the screening test (ICER = US$23,000 per QALY). Based on a threshold of GDP per capita per QALY gained (i.e. US$30,000), LDCT screening for lung cancer is unlikely to be cost-effective in New Zealand for the proposed target population under our modelling assumptions. However, it is likely to be cost-effective for Māori, a population group which carries a disproportionately high disease burden from lung cancer.