Systems mapping: a novel approach to national lung cancer screening implementation in Australia

Abstract

Background: Lung cancer screening with low-dose computed tomography has been started in some high-income countries and is being considered in others. In many settings uptake remains low. Optimal strategies to increase uptake, including for high-risk subgroups, have not been elucidated. This study used a system dynamics approach based on expert consensus to identify (I) the likely determinants of screening uptake and (II) interactions between these determinants that may affect screening uptake.

Methods: Consensus data on key factors influencing screening uptake were developed from existing literature and through two stakeholder workshops involving clinical and consumer experts. These factors were used to develop a causal loop diagram (CLD) of lung cancer screening uptake.

Results: The CLD comprised three main perspectives of importance for a lung cancer screening program: participant, primary care, and health system. Eight key drivers in the system were identified within these perspectives that will likely influence screening uptake: (I) patient stigma; (II) patient fear of having lung cancer; (III) patient health literacy; (IV) patient waiting time for a scan appointment; (V) general practitioner (GP) capacity; (VI) GP clarity on next steps after an abnormal computed tomography (CT); (VII) specialist capacity to accept referrals and undertake evaluation; and (VIII) healthcare capacity for scanning and reporting. Five key system leverage points to optimise screening uptake were also identified: (I) patient stigma influencing willingness to receive a scan; (II) GP capacity for referral to scans; (III) GP capacity to increase patients' health literacy; (IV) specialist capacity to connect patients with timely treatment; and (V) healthcare capacity to reduce scanning waiting times.

Conclusions: This novel approach to investigation of lung cancer screening implementation, based on Australian expert stakeholder consensus, provides a system-wide view of critical factors that may either limit or promote screening uptake.

Keywords: Delivery of Health Care; Lung neoplasms; mass screening; system dynamics.

Figure 1

Reinforcing (positive) and balancing (negative) feedback loops. ‘S’ = relationship between two variables change in the same direction. ‘O’ = variables change in the opposite direction (i.e., an increase in one variable causes a decrease in the connected variable).

Figure 2

Flowchart for methodological steps. CLD, causal loop diagram.

Figure 3

Causal loop diagram of lung cancer screening in Australia. LC, lung cancer; GP, general practitioner; CT, computed tomography; IT, information technology; Specialist capacity w/expertise, specialist capacity with expertise.