Who is at risk of lung nodules on low-dose CT in a Western country? A population-based

Background This population-based study aimed to identify the risk factors for lung nodules in a Western general population.
Methods We quantified the presence or absence of lung nodules among 12,055 participants of the Dutch population-based ImaLife study (≥45 years) who underwent low-dose chest computed tomography. Outcomes included the presence of 1) at least one solid lung nodule (volume ≥ 30 mm3) and 2) a clinically relevant lung nodule (volume ≥ 100 mm3). Fully adjusted multivariable logistic regression models were applied overall and stratified by smoking status to identify independent risk factors for nodules presence.
Results Of the participants (44.1% men; median age 60 years; 39.9% never smokers), we found lung nodules in 41.8% and clinically relevant nodules in 11.4%; the corresponding figures among never smokers were 38.8% and 9.5%. Factors independently associated with increased odds of having any lung nodule included male-sex, older-age, low-educational level, former smoking, asbestos exposure, and chronic obstructive pulmonary disease. Among never smokers, a family history of lung cancer increased the odds of both lung nodules and clinically relevant nodules. Among former and current smokers, low educational level was positively associated with lung nodules, whereas being overweight was negatively associated. Among current smokers, asbestos exposure and low physical activity were associated with clinically relevant nodules.
Conclusions The study provides a large-scale evaluation of lung nodules and associated risk factors in a Western general population: lung nodules and clinically relevant nodules were prevalent, and never smokers with a family history of lung cancer were a non-negligible group.