Table 2.

Cohort Studies of LDCT Identified in the Search of the Literature

Study	Number of Participants		LDCT		Was a Diagnostic Protocol in Place?	Study Duration		Number of Screens			Participant Characteristics
	Enrolled in Study	% Screened at Baseline	Collimation (mm)	Nodule Size (mm) Warranting Work up (↑ Imaging / Diagnostic Tests)		Years of Accrual	Planned Years of Follow-up from Baseline	Planned	Completed (at last report)	Conducted Annually?	Male	Age Range (or Lower Limit)	Smoking History Eligibility (current or former)
													Pack Yearsa	Years since quit
Veronesi 2008 25, 67	5,201 b	- b	2.5	> 5 / > 8 l	Yes	2004–05	-	5	2	Yes	66%	≥ 50	≥ 20	<10
Wilson 2008 26	3,755	97%	2.5	Any / ≥ 10 g	No	2002–06	3	2	2	Yes	51%	50–79	≥ 12.5 n	<10
Menezes 2010 27	3,352 b	- b	1–1.25	≥ 5 / ≥ 15	Yes	2003–07	-	6	6	Yes	46%	50–80	≥ 10	-
Sobue 2002 28	1,682	96%	10	Any	Yes o	1993–98	-	~10 f	~10	No h	88%	40–79	≥ 20	-
Swenson 2005 29, 68,69	1,520	100%	5	Any / > 8 c	Yes	1999	5	5	5	Yes	52%	50–85	≥ 20	<10
Pastorino 2003 30	1,035	100%	10	> 5	Yes	2000–01	-	5	2	Yes	71%	50–84	≥ 20	-
Henschke 2001 31, 70	1,000	-	10	Any / ≥ 6 i	Yes j	1993–98	10 m	3	3	Yes	54%	≥ 60	≥ 10	-
Bastarrika 2005 32	911 b	- b	8 d	≥ 5 / ≥ 10 l	Yes	-	-	2	2	Yes	74%	≥ 40	≥ 10	-
Diederich 2004 33, 71, 72	817	100%	5	Any / > 10 e	Yes	1995–99	6 f	6	6	Yes	72%	40–78	≥ 20	-
Novello 2005 34	520	99%	8.8	≥ 5 / > 11	Yes	2001	-	5	3	Yes	73%	54–79	≥ 20	< 10
Callol 2007 35	482	97%	10	≥ 5 / >10	Yes	2001–04	-	2	2	No k	65%	50–73	> 10	< 0.5
MacRedmond 2006 36, 73	449	100%	10	Any / ≥ 10	Yes	-	2	2	2	Yes	50%	50–74	≥ 10	-
Picozzi 2005 37	60	100%	10 p	Any / ≥ 10 e	Yes	2000–01	3	3	3	Yes	78%	57–78	≥ 20	-

Note: - = Not Reported, The column heading Nodule Size (mm) Warranting Work-up indicates first the largest size nodule warranting additional imaging, and second the largest size nodule warranting diagnostic testing

^aPack-years, defined as number of cigarettes packs smoked per day multiplied by the number of years smoked.

^bThe total number of participants enrolled was not reported, only the total number scanned at baseline, thus compliance with screening at baseline cannot be determined

^cThe following change to the protocol was reported: nodules < 4mm were initially followed with repeat CT at 6 months, but was then changed to 12 months (repeat screening)

^d297 participants were studied with a single slice helical scanner at a collimation of 8 mm and to precisely characterize any pulmonary nodule then same day high resolution CT. For the remaining 614 patients, a four-row multi-slice helical CT scanner was used – collimation = 1.25 mm.

^eNodules < 10 mm underwent repeat screening while nodules ≥ 10 were referred for biopsy

^fScreening was discontinued after at least one normal annual repeat scan in participants < 55 years old

^gThe following change to the protocol was reported: All patients with non-calcified nodules at baseline were referred to additional imaging, at repeat screening only nodules ≥ 4 mm were referred.

^hBi-annual

ⁱNodules ≤ 5 mm = follow-up with high dose CT, nodules 6–10 mm assessment of the possibility for biopsy, ≥ 11 mm = referred to pulmonary physician for biopsy

^jThe workup protocol was not rigid and could be adjusted.

^kSemi-annual.

^lDiagnostic work-up was a referral to PET scan.

^mPlanned follow-up of those with malignant disease.

ⁿAt least one-half pack per day for at least 25 years.

^oReferred to thin slice CT

^pIn the last round of screening 14 participants were scanned according to a different protocol including collimation = 3 mm.