Trial Outcomes & Findings for Low vs. Standard Dose CT for Appendicitis Trial (NCT NCT01925014)

NCT ID: NCT01925014

Last Updated: 2019-01-31

Results Overview

Negative appendectomy rate was defined as the percentage of negative (unnecessary) appendectomies among all non-incidental appendectomies. As a secondary analysis, negative appendectomy rate in an alternative definition was calculated by excluding cases with appendiceal neoplasms without superimposed appendicitis, as appendectomy would be clinically necessary in such patients. Any surgery performed for the treatment of presumed appendicitis was counted as non-incidental appendectomy, even though the surgical procedures were more extensive than simple appendectomy (e.g., ileocectomy).

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 3074 participants
• Primary outcome timeframe: 1 week after surgery
• Results posted on: 2019-01-31

Participant Flow

From 20 Korean teaching hospitals with predominantly limited experience in low-dose CT

Participant milestones

Measure	Low-dose CT 2 millisievert	Standard-dose CT 8 millisievert or lower
Overall Study STARTED	1535	1539
Overall Study COMPLETED	1526	1520
Overall Study NOT COMPLETED	9	19

Reasons for withdrawal

Measure	Low-dose CT 2 millisievert	Standard-dose CT 8 millisievert or lower
Overall Study Inappropriate enrollment	4	6
Overall Study Withdrawal by Subject	5	13

Baseline Characteristics

Missing data due to withdrawal and inappropriate enrollment.

Baseline characteristics by cohort

Measure	Low-dose CT n=1535 Participants 2 millisievert	Standard-dose CT n=1539 Participants 8 millisievert or lower	Total n=3074 Participants Total of all reporting groups
Age, Continuous	28 years n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	28 years n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	28 years n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Sex: Female, Male Female	838 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	834 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1672 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Sex: Female, Male Male	688 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	686 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1374 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Race/Ethnicity, Customized Ethnicity · Korean	1520 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	1504 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	3024 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Race/Ethnicity, Customized Ethnicity · Non-Korean	6 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	16 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	22 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Body mass index (kg/m²)	21.9 kg/m² n=1513 Participants • Missing data due to withdrawal and inappropriate enrollment.	22.1 kg/m² n=1505 Participants • Missing data due to withdrawal and inappropriate enrollment.	22.0 kg/m² n=3018 Participants • Missing data due to withdrawal and inappropriate enrollment.
Body mass index (kg/m²) < 18.5 (underweight)	151 Participants n=1513 Participants • Missing data due to withdrawal and inappropriate enrollment.	147 Participants n=1505 Participants • Missing data due to withdrawal and inappropriate enrollment.	298 Participants n=3018 Participants • Missing data due to withdrawal and inappropriate enrollment.
Body mass index (kg/m²) 18.5-24.9 (normal)	1044 Participants n=1513 Participants • Missing data due to withdrawal and inappropriate enrollment.	1005 Participants n=1505 Participants • Missing data due to withdrawal and inappropriate enrollment.	2049 Participants n=3018 Participants • Missing data due to withdrawal and inappropriate enrollment.
Body mass index (kg/m²) 25.0-29.9 (overweight)	268 Participants n=1513 Participants • Missing data due to withdrawal and inappropriate enrollment.	292 Participants n=1505 Participants • Missing data due to withdrawal and inappropriate enrollment.	560 Participants n=3018 Participants • Missing data due to withdrawal and inappropriate enrollment.
Body mass index (kg/m²) ≥ 30.0 (obese)	50 Participants n=1513 Participants • Missing data due to withdrawal and inappropriate enrollment.	61 Participants n=1505 Participants • Missing data due to withdrawal and inappropriate enrollment.	111 Participants n=3018 Participants • Missing data due to withdrawal and inappropriate enrollment.
Effective diameter (cm)	22.8 cm n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	22.8 cm n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	22.8 cm n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Effective diameter (cm) < 20.0	227 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	242 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	469 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Effective diameter (cm) 20.0-24.9	891 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	847 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1738 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Effective diameter (cm) 25.0-29.9	362 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	386 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	748 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Effective diameter (cm) ≥ 30.0	46 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	45 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	91 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Chief complaint Abdominal pain	1439 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	1439 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	2878 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Chief complaint Nausea/vomiting	37 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	35 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	72 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Chief complaint Fever	28 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	24 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	52 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Chief complaint Others	22 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	22 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	44 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Duration of symptoms ≤ 12 hr	606 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	621 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1227 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Duration of symptoms 13-24 hr	402 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	430 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	832 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Duration of symptoms 2-3 days	381 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	354 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	735 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Duration of symptoms ≥ 4 days	137 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	115 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	252 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Location of abdominal pain Right lower quadrant	1344 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	1340 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	2684 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Location of abdominal pain Suprapubic	228 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	204 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	432 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Location of abdominal pain Right flank	209 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	190 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	399 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Location of abdominal pain Periumbilical	172 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	173 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	345 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Location of abdominal pain Epigastric	156 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	118 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	274 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Location of abdominal pain Other area(s)	177 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	136 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	313 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Location of abdominal pain No pain	22 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	32 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	54 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Migration of pain Yes	466 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	452 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	918 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Migration of pain No	1060 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	1068 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	2128 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Abdominal tenderness Right lower quadrant	1305 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	1303 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	2608 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Abdominal tenderness Epigastric	147 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	151 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	298 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Abdominal tenderness Left lower quadrant	124 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	97 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	221 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Abdominal tenderness Suprapubic	112 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	115 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	227 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Abdominal tenderness Periumbilical	104 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	129 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	233 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Abdominal tenderness Other area(s)	106 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	89 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	195 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Abdominal tenderness No tenderness	142 Participants n=1526 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	139 Participants n=1520 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.	281 Participants n=3046 Participants • Patients may fall into more than one category. Missing data due to withdrawal and inappropriate enrollment.
Rebound tenderness Yes	634 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	570 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1204 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Rebound tenderness No	892 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	950 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1842 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Body temperature	36.8 ℃ n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	36.8 ℃ n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	36.8 ℃ n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
White blood cell (10³/mm³)	10.6 10³ cells/mm³ n=1519 Participants • Missing data due to withdrawal and inappropriate enrollment.	10.6 10³ cells/mm³ n=1513 Participants • Missing data due to withdrawal and inappropriate enrollment.	10.6 10³ cells/mm³ n=3032 Participants • Missing data due to withdrawal and inappropriate enrollment.
Segmented neutrophil (%)	75 percentage of neutrophils n=1519 Participants • Missing data due to withdrawal and inappropriate enrollment.	75 percentage of neutrophils n=1512 Participants • Missing data due to withdrawal and inappropriate enrollment.	75 percentage of neutrophils n=3031 Participants • Missing data due to withdrawal and inappropriate enrollment.
C-reactive protein (mg/dL)	0.8 mg/dL n=1505 Participants • Missing data due to withdrawal and inappropriate enrollment.	0.7 mg/dL n=1504 Participants • Missing data due to withdrawal and inappropriate enrollment.	0.7 mg/dL n=3009 Participants • Missing data due to withdrawal and inappropriate enrollment.
Alvarado score Low risk (0-4)	564 Participants n=1519 Participants • Missing data due to withdrawal and inappropriate enrollment.	588 Participants n=1512 Participants • Missing data due to withdrawal and inappropriate enrollment.	1152 Participants n=3031 Participants • Missing data due to withdrawal and inappropriate enrollment.
Alvarado score Indeterminate risk (5-8)	864 Participants n=1519 Participants • Missing data due to withdrawal and inappropriate enrollment.	836 Participants n=1512 Participants • Missing data due to withdrawal and inappropriate enrollment.	1700 Participants n=3031 Participants • Missing data due to withdrawal and inappropriate enrollment.
Alvarado score High risk (9-10)	91 Participants n=1519 Participants • Missing data due to withdrawal and inappropriate enrollment.	88 Participants n=1512 Participants • Missing data due to withdrawal and inappropriate enrollment.	179 Participants n=3031 Participants • Missing data due to withdrawal and inappropriate enrollment.
Appendicitis inflammatory response score Low risk (0-4)	841 Participants n=1504 Participants • Missing data due to withdrawal and inappropriate enrollment.	846 Participants n=1503 Participants • Missing data due to withdrawal and inappropriate enrollment.	1687 Participants n=3007 Participants • Missing data due to withdrawal and inappropriate enrollment.
Appendicitis inflammatory response score Indeterminate risk (5-8)	643 Participants n=1504 Participants • Missing data due to withdrawal and inappropriate enrollment.	624 Participants n=1503 Participants • Missing data due to withdrawal and inappropriate enrollment.	1267 Participants n=3007 Participants • Missing data due to withdrawal and inappropriate enrollment.
Appendicitis inflammatory response score High risk (9-12)	20 Participants n=1504 Participants • Missing data due to withdrawal and inappropriate enrollment.	33 Participants n=1503 Participants • Missing data due to withdrawal and inappropriate enrollment.	53 Participants n=3007 Participants • Missing data due to withdrawal and inappropriate enrollment.
Time of CT examination Working hours	655 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	651 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1306 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Time of CT examination After hours	871 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	869 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1740 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
CT machine 16-channel	301 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	300 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	601 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
CT machine 64-channel	385 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	381 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	766 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
CT machine 128-channel	568 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	567 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1135 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
CT machine 256-channel	272 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	272 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	544 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Target effective dose (low-dose CT vs. standard-dose CT) 2 mSv vs. 3 mSv	25 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	23 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	48 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Target effective dose (low-dose CT vs. standard-dose CT) 2 mSv vs. 5 mSv	34 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	34 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	68 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Target effective dose (low-dose CT vs. standard-dose CT) 2 mSv vs. 6 mSv	398 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	396 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	794 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Target effective dose (low-dose CT vs. standard-dose CT) 2 mSv vs. 7 mSv	527 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	523 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1050 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Target effective dose (low-dose CT vs. standard-dose CT) 2 mSv vs. 8 mSv	542 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	544 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1086 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Dose-length product (mGy·cm)	132 mGy·cm n=1525 Participants • Missing data due to withdrawal and inappropriate enrollment.	486 mGy·cm n=1518 Participants • Missing data due to withdrawal and inappropriate enrollment.	274 mGy·cm n=3043 Participants • Missing data due to withdrawal and inappropriate enrollment.
Volume CT dose index (mGy)	2.6 mGy n=1525 Participants • Missing data due to withdrawal and inappropriate enrollment.	9.4 mGy n=1518 Participants • Missing data due to withdrawal and inappropriate enrollment.	5.2 mGy n=3043 Participants • Missing data due to withdrawal and inappropriate enrollment.
Size-specific dose estimate (mGy)	4.1 mGy n=1525 Participants • Missing data due to withdrawal and inappropriate enrollment.	14.4 mGy n=1518 Participants • Missing data due to withdrawal and inappropriate enrollment.	9.1 mGy n=3043 Participants • Missing data due to withdrawal and inappropriate enrollment.
Iterative reconstruction Used	593 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	158 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	751 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Iterative reconstruction Not used	933 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	1362 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	2295 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Radiologist who made initial CT report Attending radiologist	886 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	863 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1749 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Radiologist who made initial CT report On-call radiologist or trainees	640 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	657 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1297 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Site characteristics: low-dose CT experience in the previous trial Yes	159 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	159 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	318 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Site characteristics: low-dose CT experience in the previous trial No	1367 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	1361 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	2728 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Site characteristics: number of beds < 650	363 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	360 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	723 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Site characteristics: number of beds 650-949	541 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	535 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1076 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Site characteristics: number of beds ≥ 950	622 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	625 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1247 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Site characteristics: annual number of appendectomies < 150	59 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	58 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	117 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Site characteristics: annual number of appendectomies 150-299	329 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	323 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	652 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Site characteristics: annual number of appendectomies 300-449	518 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	516 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1034 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.
Site characteristics: annual number of appendectomies ≥ 450	620 Participants n=1526 Participants • Missing data due to withdrawal and inappropriate enrollment.	623 Participants n=1520 Participants • Missing data due to withdrawal and inappropriate enrollment.	1243 Participants n=3046 Participants • Missing data due to withdrawal and inappropriate enrollment.

PRIMARY outcome

Timeframe: 1 week after surgery

Population: Patients who underwent appendectomy. Intention-to-treat.

Negative appendectomy rate was defined as the percentage of negative (unnecessary) appendectomies among all non-incidental appendectomies. As a secondary analysis, negative appendectomy rate in an alternative definition was calculated by excluding cases with appendiceal neoplasms without superimposed appendicitis, as appendectomy would be clinically necessary in such patients. Any surgery performed for the treatment of presumed appendicitis was counted as non-incidental appendectomy, even though the surgical procedures were more extensive than simple appendectomy (e.g., ileocectomy).

Outcome measures

Measure	Low-dose CT n=559 Participants 2 millisievert	Standard-dose CT n=601 Participants 8 millisievert or lower
Negative Appendectomy Rate Negative appendectomy (NA) rate	22 Participants	16 Participants
Negative Appendectomy Rate Not counting appendiceal neoplasm(s) as NA	21 Participants	16 Participants

SECONDARY outcome

Timeframe: 1 week after surgery

Population: Patients confirmed as having appendicitis. Intention-to-treat.

The percentage of perforated appendicitis among confirmed appendicitis cases.

Outcome measures

Measure	Low-dose CT n=524 Participants 2 millisievert	Standard-dose CT n=564 Participants 8 millisievert or lower
Appendiceal Perforation Rate	182 Participants	176 Participants

SECONDARY outcome

Timeframe: 3 months after CT

Population: Intention-to-treat.

Appendectomy rate. The percentage of appendectomies among all randomized cases.

Outcome measures

Measure	Low-dose CT n=1535 Participants 2 millisievert	Standard-dose CT n=1539 Participants 8 millisievert or lower
Number of Appendectomies	559 Participants	601 Participants

SECONDARY outcome

Timeframe: 1 week after surgery

Population: Intention-to-treat.

The percentage of negative appendectomies among all randomized cases. In January, 2016, when more than 2000 patients were enrolled, the data and safety monitoring board noted a between-group imbalance in the number of appendectomies. Because of the concern that such an imbalance might potentially jeopardize the comparability for the prespecified endpoints, the study protocol was amended to adopt the following additional secondary endpoints, which were assessed among all randomly assigned patients: the number of appendectomies, number of negative appendectomies, prevalence of perforated appendicitis, and prevalence of non-perforated appendicitis.

Outcome measures

Measure	Low-dose CT n=1535 Participants 2 millisievert	Standard-dose CT n=1539 Participants 8 millisievert or lower
Number of Negative Appendectomies	22 Participants	16 Participants

SECONDARY outcome

Timeframe: 1 week after surgery

Population: Intention-to-treat.

The percentage (i.e., prevalence) of perforated appendicitis among all randomized cases. In January, 2016, when more than 2000 patients were enrolled, the data and safety monitoring board noted a between-group imbalance in the number of appendectomies. Because of the concern that such an imbalance might potentially jeopardize the comparability for the prespecified endpoints, the study protocol was amended to adopt the following additional secondary endpoints, which were assessed among all randomly assigned patients: the number of appendectomies, number of negative appendectomies, prevalence of perforated appendicitis, and prevalence of non-perforated appendicitis.

Outcome measures

Measure	Low-dose CT n=1535 Participants 2 millisievert	Standard-dose CT n=1539 Participants 8 millisievert or lower
Prevalence of Perforated Appendicitis	182 Participants	176 Participants

SECONDARY outcome

Timeframe: 1 week after surgery

Population: Intention-to-treat.

The percentage (i.e., prevalence) of non-perforated appendicitis among all randomized cases. In January, 2016, when more than 2000 patients were enrolled, the data and safety monitoring board noted a between-group imbalance in the number of appendectomies. Because of the concern that such an imbalance might potentially jeopardize the comparability for the prespecified endpoints, the study protocol was amended to adopt the following additional secondary endpoints, which were assessed among all randomly assigned patients: the number of appendectomies, number of negative appendectomies, prevalence of perforated appendicitis, and prevalence of non-perforated appendicitis.

Outcome measures

Measure	Low-dose CT n=1535 Participants 2 millisievert	Standard-dose CT n=1539 Participants 8 millisievert or lower
Prevalence of Non-perforated Appendicitis	342 Participants	388 Participants

SECONDARY outcome

Timeframe: 1 week after CT

Population: Intention-to-treat.

The proportion of patients requiring additional imaging test(s) in order to diagnose or rule out appendicitis.

Outcome measures

Measure	Low-dose CT n=1535 Participants 2 millisievert	Standard-dose CT n=1539 Participants 8 millisievert or lower
Need for Additional Imaging Test(s)	39 Participants	41 Participants

SECONDARY outcome

Timeframe: 3 months after CT

Population: Intention-to-treat.

• The interval from CT acquisition to appendectomy in patients undergoing appendectomy. Interval appendectomies following percutaneous abscess drainage and/or medical treatment were not included in this analysis.
• The interval from CT acquisition to hospital discharge in patients not undergoing surgery.

Outcome measures

Measure	Low-dose CT n=1535 Participants 2 millisievert	Standard-dose CT n=1539 Participants 8 millisievert or lower
Delay in Patient Disposition Interval between CT and appendectomy	5.3 Hours Interval 3.1 to 9.7	5.4 Hours Interval 3.4 to 10.6
Delay in Patient Disposition Interval between CT and discharge without surgery	1.7 Hours Interval 0.9 to 3.9	1.6 Hours Interval 0.9 to 4.1

SECONDARY outcome

Timeframe: 3 months after CT

Population: Patients who underwent appendectomy. Intention-to-treat. Interval appendectomies following percutaneous abscess drainage and/or medical treatment were not included in this analysis.

The interval from CT acquisition to hospital discharge after appendectomy.

Outcome measures

Measure	Low-dose CT n=538 Participants 2 millisievert	Standard-dose CT n=590 Participants 8 millisievert or lower
Length of Hospital Stay Associated With Appendectomy	3.0 Days Interval 2.4 to 4.0	2.9 Days Interval 2.2 to 3.9

SECONDARY outcome

Timeframe: 3 months after CT

Population: Patients with incomplete reference standards were not included in these analyses. Intention-to-treat.

• Area under the receiver-operating-characteristic curve (AUC).

Outcome measures

Measure	Low-dose CT n=1459 Participants 2 millisievert	Standard-dose CT n=1429 Participants 8 millisievert or lower
Diagnostic Performance of CT Reports - AUC	0.983 AUC	0.986 AUC

SECONDARY outcome

Timeframe: 3 months after CT

Population: Patients with incomplete reference standards were not included in these analyses. Intention-to-treat.

• Diagnostic sensitivity and specificity: the 5-grade likelihood scores for appendicitis were collapsed into binary responses with a decision threshold of a score ≥ 3 as positive for the diagnosis.
• Sensitivity is a proportion of the positive test among the patient confirmed as having appendicitis.
• Specificity is a proportion of the negative test among the patient confirmed as not having appendicitis.

Outcome measures

Measure	Low-dose CT n=1459 Participants 2 millisievert	Standard-dose CT n=1429 Participants 8 millisievert or lower
Diagnostic Performance of CT Reports - Sensitivity and Specificity Sensitivity (%)	97.1 percentage	98.0 percentage
Diagnostic Performance of CT Reports - Sensitivity and Specificity Specificity (%)	95.8 percentage	94.0 percentage

SECONDARY outcome

Timeframe: 3 months after CT

Population: Patients with incomplete reference standards were not included in these analyses. Intention-to-treat.

• Likelihood score for appendicitis in patients confirmed as having appendicitis.
• Likelihood score for appendicitis in patients confirmed as not having appendicitis.

Grade 1 denotes appendicitis definitely absent; grade 2, appendicitis probably absent; grade 3, indeterminate for the presence of appendicitis; grade 4, appendicitis probably present; and grade 5, appendicitis definitely present.

Outcome measures

Measure	Low-dose CT n=1459 Participants 2 millisievert	Standard-dose CT n=1429 Participants 8 millisievert or lower
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as not having appendicitis · Grade 2	154 Participants	103 Participants
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as not having appendicitis · Grade 3	16 Participants	34 Participants
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as not having appendicitis · Grade 4	14 Participants	10 Participants
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as having appendicitis · Grade 1	6 Participants	6 Participants
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as having appendicitis · Grade 2	9 Participants	5 Participants
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as having appendicitis · Grade 3	18 Participants	19 Participants
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as having appendicitis · Grade 4	91 Participants	68 Participants
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as having appendicitis · Grade 5	400 Participants	466 Participants
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as not having appendicitis · Grade 1	742 Participants	710 Participants
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis Patients confirmed as not having appendicitis · Grade 5	9 Participants	8 Participants

SECONDARY outcome

Timeframe: 3 months after CT

Population: Patients with incomplete reference standards were not included in these analyses. Intention-to-treat.

The frequency of indeterminate CT interpretation (grade 3). Grade 1 denotes appendicitis definitely absent; grade 2, appendicitis probably absent; grade 3, indeterminate for the presence of appendicitis; grade 4, appendicitis probably present; and grade 5, appendicitis definitely present.

Outcome measures

Measure	Low-dose CT n=1459 Participants 2 millisievert	Standard-dose CT n=1429 Participants 8 millisievert or lower
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Indeterminate Interpretation (Grade 3)	34 Participants	53 Participants

SECONDARY outcome

Timeframe: 3 months after CT

Population: Patients confirmed as not having appendicitis. Intention-to-treat.

The frequency of normal appendix visualization at CT. Grade 0 denotes appendix not identified; grade 1, unsure or partly visualized; and grade 2, clearly and entirely visualized.

Outcome measures

Measure	Low-dose CT n=935 Participants 2 millisievert	Standard-dose CT n=865 Participants 8 millisievert or lower
Diagnostic Confidence in Ruling Out Appendicitis: Normal Appendix Visualization Grade 0	36 Participants	14 Participants
Diagnostic Confidence in Ruling Out Appendicitis: Normal Appendix Visualization Grade 1	137 Participants	64 Participants
Diagnostic Confidence in Ruling Out Appendicitis: Normal Appendix Visualization Grade 2	762 Participants	787 Participants

SECONDARY outcome

Timeframe: 3 months after CT

Population: Patients confirmed to have appendicitis. Intention-to-treat.

• Diagnostic sensitivity: the number of correct detections of the perforation divided by the number of cases of perforated appendicitis.
• Diagnostic specificity: the number of correct ruling out the perforation divided by the number of cases of appendicitis without perforation.

Outcome measures

Measure	Low-dose CT n=524 Participants 2 millisievert	Standard-dose CT n=564 Participants 8 millisievert or lower
Diagnosis of Appendiceal Perforation at CT Sensitivity (%)	43 Percentage	43 Percentage
Diagnosis of Appendiceal Perforation at CT Specificity (%)	89 Percentage	91 Percentage

Adverse Events

Low-dose CT

Serious events: 43 serious events

Other events: 0 other events

Deaths: 0 deaths

Standard-dose CT

Serious events: 40 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Measure	Low-dose CT n=1535 participants at risk 2 millisievert	Standard-dose CT n=1539 participants at risk 8 millisievert or lower
Blood and lymphatic system disorders Disseminated intravascular coagulation	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Blood and lymphatic system disorders Leukocytosis	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Gastrointestinal disorders Abdominal pain	0.39% 6/1535 • Number of events 6 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.52% 8/1539 • Number of events 8 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Gastrointestinal disorders Diarrhea	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Gastrointestinal disorders Enterocolitis	0.26% 4/1535 • Number of events 4 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Gastrointestinal disorders Gastritis	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.13% 2/1539 • Number of events 2 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Gastrointestinal disorders Gastrointestinal disorders-other, specify	0.13% 2/1535 • Number of events 2 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Gastrointestinal disorders Ileus	0.20% 3/1535 • Number of events 3 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.13% 2/1539 • Number of events 2 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Gastrointestinal disorders Vomiting	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
General disorders Fever	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Hepatobiliary disorders Cholecystitis	0.20% 3/1535 • Number of events 3 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.13% 2/1539 • Number of events 2 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Hepatobiliary disorders Hepatic failure	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Immune system disorders Anaphylaxis	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Infections and infestations Joint infection	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Infections and infestations Kidney infection	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.13% 2/1539 • Number of events 2 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Infections and infestations Laryngitis	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Infections and infestations Pelvic infection	0.26% 4/1535 • Number of events 4 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.58% 9/1539 • Number of events 9 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Infections and infestations Skin infection	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Infections and infestations Urinary tract infection	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Infections and infestations Wound infection	0.26% 4/1535 • Number of events 4 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.13% 2/1539 • Number of events 2 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Injury, poisoning and procedural complications Fracture	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Injury, poisoning and procedural complications Large intestinal anastomotic leak	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Musculoskeletal and connective tissue disorders Arthritis	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Musculoskeletal and connective tissue disorders Back pain	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Musculoskeletal and connective tissue disorders Neck pain	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.13% 2/1539 • Number of events 2 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Nervous system disorders Hydrocephalus	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Nervous system disorders Intracranial hemorrhage	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Nervous system disorders Ischemia cerebrovascular	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Nervous system disorders Neuralgia	0.00% 0/1535 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.06% 1/1539 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Psychiatric disorders Psychosis	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Renal and urinary disorders Urinary tract obstruction	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Reproductive system and breast disorders Pelvic pain	0.13% 2/1535 • Number of events 2 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Respiratory, thoracic and mediastinal disorders Pleural effusion	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.00% 0/1539 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.
Surgical and medical procedures Surgical and medical procedures- other, specify	0.07% 1/1535 • Number of events 1 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.	0.13% 2/1539 • Number of events 2 • 3 months Detailed in Ahn S, LOCAT Group. Trials 2014:15:28.

Other adverse events

Adverse event data not reported

Additional Information

Kyoung Ho Lee

The LOCAT Group

Phone: 82317877607

Email: kholeemail@gmail.com

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place