Trial Outcomes & Findings for Diagnosis of Acute Appendicitis: Low-dose Computed Tomography (CT) Versus Standard-dose CT (NCT NCT00913380)
NCT ID: NCT00913380
Last Updated: 2011-09-12
Results Overview
Number of participants with unnecessary appendectomies (removal of un-inflamed appendix)
COMPLETED
PHASE3
891 participants
1 week after surgery
2011-09-12
Participant Flow
Dates of the recruitment period: September 2009 to January 2011 Types of location: an emergency department in an urban tertiary hospital in Korea
None of the enrolled participants were excluded from the trial before assignment to group.
Participant milestones
| Measure |
Low-dose CT
Aimed to 2 mSv in an average patient
|
Standard-dose CT
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
CT Examination
STARTED
|
444
|
447
|
|
CT Examination
COMPLETED
|
444
|
447
|
|
CT Examination
NOT COMPLETED
|
0
|
0
|
|
Clinical Outcomes
STARTED
|
444
|
447
|
|
Clinical Outcomes
COMPLETED
|
438
|
441
|
|
Clinical Outcomes
NOT COMPLETED
|
6
|
6
|
Reasons for withdrawal
| Measure |
Low-dose CT
Aimed to 2 mSv in an average patient
|
Standard-dose CT
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Clinical Outcomes
Lost to Follow-up
|
6
|
6
|
Baseline Characteristics
Diagnosis of Acute Appendicitis: Low-dose Computed Tomography (CT) Versus Standard-dose CT
Baseline characteristics by cohort
| Measure |
Low-dose CT
n=444 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=447 Participants
Aimed to 8 mSv in an average patient
|
Total
n=891 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age Continuous
Age (year)
|
29 year
n=5 Participants
|
30 year
n=7 Participants
|
30 year
n=5 Participants
|
|
Sex: Female, Male
Female
|
276 Participants
n=5 Participants
|
263 Participants
n=7 Participants
|
539 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
168 Participants
n=5 Participants
|
184 Participants
n=7 Participants
|
352 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Korean
|
441 participants
n=5 Participants
|
445 participants
n=7 Participants
|
886 participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Non-Korean
|
3 participants
n=5 Participants
|
2 participants
n=7 Participants
|
5 participants
n=5 Participants
|
|
Body mass index
< 18.5 (underweight)
|
62 kg/m^2
n=5 Participants
|
60 kg/m^2
n=7 Participants
|
122 kg/m^2
n=5 Participants
|
|
Body mass index
18.5-24.9 (normal)
|
312 kg/m^2
n=5 Participants
|
301 kg/m^2
n=7 Participants
|
613 kg/m^2
n=5 Participants
|
|
Body mass index
≥ 25.0 (overweight to extremely obese)
|
70 kg/m^2
n=5 Participants
|
86 kg/m^2
n=7 Participants
|
156 kg/m^2
n=5 Participants
|
|
White blood cell
|
10.7 x10^3/mm^3
n=5 Participants
|
10.8 x10^3/mm^3
n=7 Participants
|
10.8 x10^3/mm^3
n=5 Participants
|
|
Segmented neutrophil
|
77.0 Percentage of peripheral Leukocytes
n=5 Participants
|
77.3 Percentage of peripheral Leukocytes
n=7 Participants
|
77.3 Percentage of peripheral Leukocytes
n=5 Participants
|
|
C-reactive protein
|
0.5 mg/dL
n=5 Participants
|
0.7 mg/dL
n=7 Participants
|
0.6 mg/dL
n=5 Participants
|
|
CT scanner
16-detector CT
|
177 participants
n=5 Participants
|
191 participants
n=7 Participants
|
368 participants
n=5 Participants
|
|
CT scanner
64-detector CT
|
154 participants
n=5 Participants
|
144 participants
n=7 Participants
|
298 participants
n=5 Participants
|
|
CT scanner
256-detector CT
|
113 participants
n=5 Participants
|
112 participants
n=7 Participants
|
225 participants
n=5 Participants
|
|
Radiologist
Abdominal radiologist
|
217 participants
n=5 Participants
|
225 participants
n=7 Participants
|
442 participants
n=5 Participants
|
|
Radiologist
Non-abdominal radiologist
|
227 participants
n=5 Participants
|
222 participants
n=7 Participants
|
449 participants
n=5 Participants
|
PRIMARY outcome
Timeframe: 1 week after surgeryPopulation: Participants who underwent non-incidental appendectomy. Intention to treat. Complete case analysis.
Number of participants with unnecessary appendectomies (removal of un-inflamed appendix)
Outcome measures
| Measure |
Low-dose CT
n=172 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=186 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Negative Appendectomy
Negative appendectomy
|
6 participants
|
6 participants
|
|
Negative Appendectomy
Not negative appendectomy
|
166 participants
|
180 participants
|
SECONDARY outcome
Timeframe: 1 week after CTPopulation: All participants included in outcome analyses. Intention to treat. Complete case analysis.
Number of participants who need additional imaging test(s) to diagnose or rule out appendicitis
Outcome measures
| Measure |
Low-dose CT
n=438 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=441 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Additional Imaging Test(s)
Additional imaging
|
14 participants
|
7 participants
|
|
Additional Imaging Test(s)
No additional imaging
|
424 participants
|
434 participants
|
SECONDARY outcome
Timeframe: 1 week after surgeryPopulation: Participants confirmed to have appendicitis. Intention to treat. Complete case analysis.
Number of participants with appendiceal perforation
Outcome measures
| Measure |
Low-dose CT
n=166 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=180 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Appendiceal Perforation
Perforation
|
44 participants
|
42 participants
|
|
Appendiceal Perforation
No perforation
|
122 participants
|
138 participants
|
SECONDARY outcome
Timeframe: 1 day after surgeryPopulation: Participants who underwent non-incidental appendectomy. Intention to treat. Complete case analysis.
Time interval between the CT acquisition and non-incidental appendectomy
Outcome measures
| Measure |
Low-dose CT
n=172 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=186 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Interval Between CT and Appendectomy
|
7.1 hr
Interval 4.3 to 11.7
|
5.6 hr
Interval 3.4 to 9.2
|
SECONDARY outcome
Timeframe: 3 months after CTPopulation: Participants who did not undergo surgery. Intention to treat. Complete case analysis.
Time interval between the CT acquisition and discharge without surgery
Outcome measures
| Measure |
Low-dose CT
n=249 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=246 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Interval Between CT and Discharge Without Surgery
|
2.5 hr
Interval 1.5 to 4.2
|
2.4 hr
Interval 1.4 to 4.4
|
SECONDARY outcome
Timeframe: 3 months after CTPopulation: Participants who underwent non-incidental appendectomy. Intention to treat. Complete case analysis.
Time interval between the CT acquisition and discharge after appendectomy
Outcome measures
| Measure |
Low-dose CT
n=172 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=186 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Interval From CT to Discharge After Appendectomy
|
3.4 day
Interval 2.7 to 4.1
|
3.2 day
Interval 2.5 to 4.1
|
SECONDARY outcome
Timeframe: 3 months after CTPopulation: Participants confirmed to have appendicitis. Intention to treat. Complete case analysis. There can be missing data if CT report was not made following predefined structured format.
Grade 1. Definitely absent. Clinical observation is recommended. Grade 2. Probably absent. Clinical observation is recommended. Grade 3. Indeterminate. Clinical observation or surgical exploration is recommended. Grade 4. Probably present. Surgical exploration is recommended. Grade 5. Definitely present. Surgical exploration is recommended. The data is used to calculate sensitivity, specificity, area under receiver-operating-curve and to measure diagnostic confidence.
Outcome measures
| Measure |
Low-dose CT
n=166 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=180 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Having Appendicitis
Grade 1
|
2 participants
|
4 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Having Appendicitis
Grade 2
|
7 participants
|
5 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Having Appendicitis
Grade 3
|
13 participants
|
11 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Having Appendicitis
Grade 4
|
53 participants
|
34 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Having Appendicitis
Grade 5
|
90 participants
|
126 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Having Appendicitis
Missing
|
1 participants
|
0 participants
|
SECONDARY outcome
Timeframe: 3 months after CTPopulation: Participants confirmed not to have appendicitis. Intention to treat. Complete case analysis. There can be missing data if CT report was not made following predefined structured format.
Grade 1. Definitely absent. Clinical observation is recommended. Grade 2. Probably absent. Clinical observation is recommended. Grade 3. Indeterminate. Clinical observation or surgical exploration is recommended. Grade 4. Probably present. Surgical exploration is recommended. Grade 5. Definitely present. Surgical exploration is recommended. The data are used to calculate sensitivity, specificity, area under receiver-operating-curve and to measure diagnostic confidence.
Outcome measures
| Measure |
Low-dose CT
n=272 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=261 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Not Having Appendicitis
Grade 2
|
65 participants
|
38 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Not Having Appendicitis
Grade 1
|
185 participants
|
206 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Not Having Appendicitis
Grade 3
|
11 participants
|
11 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Not Having Appendicitis
Grade 4
|
3 participants
|
3 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Not Having Appendicitis
Grade 5
|
4 participants
|
2 participants
|
|
Likelihood of Appendicitis in CT Report in Patients Confirmed as Not Having Appendicitis
Missing
|
4 participants
|
1 participants
|
SECONDARY outcome
Timeframe: 3 months after CTPopulation: Participants confirmed to have appendicitis. Intention to treat. Complete case analysis. There can be missing data if CT report was not made following predefined structured format.
True positive: Perforation was rated as present in CT report and confirmed as present. False positive: Perforation was rated as present in CT report and confirmed as absent. True negative: Perforation was rated as absent in CT report and confirmed as absent. False negative: Perforation was rated as absent in CT report and confirmed as present. The data are used to calculate sensitivity and specificity.
Outcome measures
| Measure |
Low-dose CT
n=166 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=180 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Diagnosis of Appendiceal Perforation in CT in Patients With Confirmed Appendicitis.
True positive
|
16 participants
|
23 participants
|
|
Diagnosis of Appendiceal Perforation in CT in Patients With Confirmed Appendicitis.
False positive
|
11 participants
|
17 participants
|
|
Diagnosis of Appendiceal Perforation in CT in Patients With Confirmed Appendicitis.
True negative
|
110 participants
|
121 participants
|
|
Diagnosis of Appendiceal Perforation in CT in Patients With Confirmed Appendicitis.
False negative
|
28 participants
|
19 participants
|
|
Diagnosis of Appendiceal Perforation in CT in Patients With Confirmed Appendicitis.
Missing
|
1 participants
|
0 participants
|
SECONDARY outcome
Timeframe: 3 months after CTPopulation: Participants confirmed not to have appendicitis. Intention to treat. Complete case analysis. There can be missing data if CT report was not made following predefined structured format.
Grade 0. Not identified Grade 1. Unsure or partly visualized Grade 2. Clearly and entirely visualized
Outcome measures
| Measure |
Low-dose CT
n=272 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=261 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Visualization of the Normal Appendix
Grade 0
|
18 participants
|
13 participants
|
|
Visualization of the Normal Appendix
Grade 1
|
41 participants
|
20 participants
|
|
Visualization of the Normal Appendix
Grade 2
|
209 participants
|
227 participants
|
|
Visualization of the Normal Appendix
Missing
|
4 participants
|
1 participants
|
OTHER_PRE_SPECIFIED outcome
Timeframe: 1 day after CTPopulation: All participants who underwent CT. Intention to treat. Complete case analysis.
Radiation dose is measured in terms of dose-length product (mGy•cm) as displayed in the CT console. The "length" indicates the scan range.
Outcome measures
| Measure |
Low-dose CT
n=444 Participants
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=447 Participants
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Radiation Dose
|
116 mGy•cm
Interval 94.0 to 124.0
|
521 mGy•cm
Interval 448.0 to 564.0
|
OTHER_PRE_SPECIFIED outcome
Timeframe: 1 day after CTAge- and sex-specific carcinogenic risk induced by CT radiation. This is not an actual measurement but an estimate of the stochastic risk, based on assumption and calculation from radiation dose used.
Outcome measures
Outcome data not reported
Adverse Events
Low-dose CT
Standard-dose CT
Serious adverse events
| Measure |
Low-dose CT
n=444 participants at risk
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=447 participants at risk
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Gastrointestinal disorders
Abdominal pain
|
1.4%
6/444 • Number of events 6 • 3 months
|
1.3%
6/447 • Number of events 6 • 3 months
|
|
Gastrointestinal disorders
Ileus
|
0.90%
4/444 • Number of events 4 • 3 months
|
0.89%
4/447 • Number of events 4 • 3 months
|
|
Injury, poisoning and procedural complications
Wound complication
|
0.68%
3/444 • Number of events 3 • 3 months
|
0.00%
0/447 • 3 months
|
|
General disorders
Fever
|
0.00%
0/444 • 3 months
|
0.22%
1/447 • Number of events 1 • 3 months
|
Other adverse events
| Measure |
Low-dose CT
n=444 participants at risk
Aimed to 2 mSv in an average patient
|
Standard-dose CT
n=447 participants at risk
Aimed to 8 mSv in an average patient
|
|---|---|---|
|
Gastrointestinal disorders
Abdominal pain
|
0.23%
1/444 • Number of events 1 • 3 months
|
0.22%
1/447 • Number of events 1 • 3 months
|
Additional Information
Kyoung Ho Lee
Seoul National University Bundang Hospital
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place