Table 2. Comparison of different types of diagnoses.

Characteristics of lesions	F	A	DX	E	Difference 1	Difference 2	Difference 3	P value 1	P value 2	P value 3
Total group
Diameter (mm)	42.27±0.46	33.69±0.57	31.92±0.51	26.84±0.48	2.36±0.33	3.48±0.30	6.14±0.36	<0.001	<0.001	<0.001
	39 [24–54]	29 [19–48]	26 [16–48]	21 [14–37]	0 [0–3]	0 [0–3]	0 [0–10]
Duration (days)	0±0	221.72±9.69	447.91±14.54	629.32±15.35	161.83±10.66	157.44±8.19	319.28±12.64	<0.001	<0.001	<0.001
	0 [0–0]	5 [1–268]	206 [13–753]	459 [160–933]	0 [0–83]	0 [0–187]	64 [0–479]
Subgroup (hidden, 1,155 radiographs)
Diameter (mm)	46.15±0.55	40.30±0.74	35.08±0.61	30.36±0.60	4.97±0.35	3.06±0.31	8.03±0.44	<0.001	<0.001	<0.001
	44 [31–56]	37 [24–53]	19 [13–32]	29 [16–41]	0 [0–0]	0 [0–3]	0 [0–13]
Duration (days)	0±0	178.67±11.49	474.45±19.61	667.84±20.84	212.57±14.86	162.29±10.66	374.86±17.31	<0.001	<0.001	<0.001
	0 [0–0]	1 [1–162]	201 [23–755]	480 [160–953]	0 [0–159]	0 [0–195]	63 [0–547]
Subgroup (open, 595 radiographs)
Diameter (mm)	34.75±0.76	24.62±0.73	26.56±0.86	20.67±0.70	1.82±0.62	4.28±0.63	2.46±0.59	0.613	<0.001	<0.001
	29 [21–48]	19 [14–27]	19 [14–29]	17 [13–22]	0 [0–0]	0 [0–2]	0 [0–6]
Duration (days)	0±0	305.29±17.27	401.62±20.39	561.92±20.96	63.35±11.22	148.04±12.34	211.38±14.93	<0.001	<0.001	<0.001
	0 [0–0]	91 [1–506]	238 [13–637]	418 [155–829]	0 [0–1]	0 [0–187]	64 [0–310]
Subgroup (pulmonologist duration <97 months, 900 radiographs)
Diameter (mm)	42.27±0.64	33.60±0.83	31.06±0.71	26.21±0.66	3.43±0.49	3.20±0.41	6.62±0.53	<0.001	<0.001	<0.001
	39 [24–54]	27 [19–48]	24 [16–45]	20 [14–34]	0 [0–5]	0 [0–3]	0 [0–11]
Duration (days)	0±0	215.79±13.46	471.74±20.73	665.21±21.89	193.18±15.89	171.36±10.84	364.54±18.65	<0.001	<0.001	<0.001
	0 [0–0]	1 [1–196]	0 [0–157]	506 [186–953]	0 [0–157]	0 [0–240]	116 [0–536]
Subgroup (pulmonologist duration ≥97 months, 850 radiographs)
Diameter (mm)	42.27±0.66	33.77±0.79	32.84±0.74	27.49±0.69	1.85±0.41	3.77±0.43	5.62±0.49	<0.001	<0.001	<0.001
	39 [24–54]	29 [19–48]	29 [16–48]	22 [14–37]	0 [0–0]	0 [0–3]	0 [0–8]
Duration (days)	0±0	227.99±13.98	422.02±20.28	590.13±21.36	128.64±14.00	142.70±12.34	271.35±16.79	<0.001	<0.001	<0.001
	0 [0–0]	13 [1–268]	188 [9–637]	431 [137–844]	0 [0–9]	0 [0–170]	1 [0–393]

Difference 1 and P value 1, A vs. DX; Difference 2 and P value 2, DX vs. E; Difference 3 and P value 3, A vs. E. Missing data were treated using the Last Observation Carried Forward (LOCF) method. Data are expressed as mean ± standard deviation or median and interquartile range; P values were calculated using the Wilcoxon rank sum test. A, earliest image with which cancer was diagnosed when the radiographs were viewed without time constraints, distractors, and side-by-side cropped images; DX, earliest image suggestive of cancer when viewing side-by-side cropped radiographs; E, earliest image suggestive of a lesion when viewing side-by-side cropped radiographs; F, image at the time of actual diagnosis. MD, medical doctor.