Appendicitis, Carcinogenesis, Computed Tomography, Radiation Exposure
Conditions
Brief summary
The purpose of this study is to compare the incidence rate of leukemia between CT-exposed and CT-unexposed group in patients who underwent appendectomy in South Korea.
Detailed description
South Korea has a single-payer healthcare system, administered by National Health Insurance Service (NHIS). As healthcare providers in South Korea need to claim reimbursement to NHIS for the vast majority of diagnostic and therapeutic procedures, the NHIS database enabled us to construct a large cohort who did or did not undergo CT for appendicitis. The purpose of this study is to compare the incidence rate of cancer between CT-exposed and CT-unexposed group in patients who underwent appendectomy in South Korea.
Interventions
RADIATIONAbdomen CT
Patients are divided into CT-exposed or unexposed group according to the presence of claims codes of abdominopelvic CT conducted within seven days before and after appendectomy. The seven-day threshold is arbitrarily determined considering the delay in the diagnosis of appendicitis and the postoperative examination for surgical complication.
Sponsors
National Research Foundation of Korea
Seoul National University Bundang Hospital
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Healthy volunteers
No
Inclusion criteria
* Patients will be entered in the cohort on the date of appendectomy under the diagnosis of appendicitis
Exclusion criteria
* (a) patients who had a cancer diagnosis before the date of appendectomy, * (b) those who had prior experience of CT examination more than 7 days before appendectomy, * (c) those who had syndromes or diseases predisposing cancers, * (d) those whose diagnosis was changed to appendiceal cancer and * (e) those whose follow-up duration was shorter than a lag period.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Age and sex-standardized incidence rate ratio (IRR) for malignancies of hematologic system | Cancer occurrence after a lag period (2 years) | Hematologic malignancies are categorized into lymphomas, multiple myeloma, leukemias, myelodysplasia and others using ICD-10 codes. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Age and sex-standardized incidence rate ratio (IRR) for malignancies of abdominal organs | Cancer occurrence after a lag period (2 years) | age and sex-standardized IRRs for malignancies of abdominal organs for CT-exposed versus unexposed patients. |
| Age and sex-standardized incidence rate ratio (IRR) for all cancers | Cancer occurrence after a lag period (2 years) | age and sex-standardized IRRs for all cancers for CT-exposed versus unexposed patients. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Sensitivity analysis | Cancer occurrence after different lag periods (6 months, 1 year, 3 years and 5 years) | Various lag periods will be applied for the outcomes. |
| Subgroup analysis by subsequent CT scans conducted more than 7 days after appendectomy | CT undergone more than 7 days after appendectomy will be counted. | IRR in patients who underwent CT after appendectomy IRR in patients who did not undergo CT after appendectomy |
| Subgroup analysis | Cancer occurrence after a lag period (2 years) | by age and sex |
Countries
South Korea
Contacts
Primary ContactJi Hoon Park, MD
Backup ContactKyung Hee Lee, MD
Outcome results
None listed