OBJECTIVES: Our first study objective is to assess the range of lung cancer screening intervals compared within cost-effectiveness analyses (CEAs) of low-dose computed tomography (LDCT) and to examine the implications for the strategies identified as optimally cost-effective; the second objective was to examine if and how risk subgroup specific policies were considered.

METHODS: PubMed, Embase and Web of Science were searched for model-based CEAs of LDCT lung screening. The retrieved studies were assessed to examine if the analyses considered sufficient strategy variation to permit incremental estimation of cost-effectiveness ratios. Regarding risk selection, we examined if analyses considered alternative risk strata in separate analyses or as alternative risk-based eligibility criteria for screening.

RESULTS: The search identified 33 eligible CEAs, 23 of which only considered one screening frequency. Of the 10 considering multiple screening intervals, only 4 analyses included intervals longer than 2 years. Within the 10 studies considering multiple intervals, the optimal policy choice would differ in 5 if biennial intervals or longer had not been considered. Nineteen studies conducted risk subgroup analyses, 12 of which assumed subgroup-specific policies were possible and 7 which assumed a common screening policy applies to all those screened.

CONCLUSIONS: The comparison of multiple strategies is recognised as good practice in CEA when seeking optimal policies. Studies that do include multiple intervals indicate that screening intervals longer than one year can be relevant. The omission of intervals of two years or longer from CEAs of LDCT screening could lead to the adoption of sub-optimal policies. There also is scope for greater consideration to risk-stratified policies which tailor screening intensity to estimated disease risk. Policy makers should take care interpreting current evidence before implementing lung screening.