3.

Transparency assessment of multiple-use models

Model	Variable included	Model expression	Limitation	Financial support	Conflict of interest	Validation
LLP, Liverpool Lung Project; PLCO, the Prostate, Lung, Colorectal and Ovarian; Y, reported; N, no reported.
Bach	Y	N	It does not distinguish among the risks of different histologic types of lung cancer, and it is relevant only to one subset (albeit a large subset) of at-risk individuals — those aged 50 years or older who have a smoking history.	Research institution; National project fund	N	Internal validation/ Cross-validation
Spitz (2007)	Y	N	The models may not be sufficiently discriminatory to allow accurate risk assessment at the individual level. They are needed to be validated in independent populations.	Research institution; National project fund	N	External validation
Spitz (2008)	Y	N	Without an independent validation.	Research institution; National project fund	Y	Cross- validation
LLP	Y	Y	More work is needed to test the applicability of the model in diverse populations, including those from diverse geographic regions.	Research institution; Foundation	N	Cross- validation
LLPi	Y	Y	More work is needed to test the applicability of the model in diverse populations, including those from diverse geographic regions.	Region project fund; Foundation	Y	Internal validation
PLCO (2009)	Y	N	The study model was developed in asymptomatic individuals. It is unclear whether its performance will be substantially different in symptomatic individuals presenting to clinicians.	National project fund	N	Internal validation
PLCO (2011)	Y	N	The models may not be generalizable to other populations. Data on exposure to radon, asbestos, second-hand smoke, occupational carcinogens, and history of adult pneumonia were not available for analysis.	National project fund	N	Internal validation/ External validation
PLCOM2012	Y	N	Excluded persons who had never smoked.	Research institution	N	External validation
Etzel	Y	N	The study was hospital-based and the controls were drawn only from the metropolitan area of Houston, Texas; therefore, the results may vary in other geographic locations; the sample size of the study was small.	National project fund	Y	Internal validation/ External validation
Pittsburgh	Y	N	The model is derived in preselected high-risk populations and not necessarily applicable to the general population of smokers, and it was derived and tested in the United States and applicability to other populations will need to be tested.	Research institution; National project fund	N	External validation
Hoggart	Y	N	Measures of carcinogens are limited to occupational exposures.	European Union project fund	Y	External validation