Clinical trial NCT04081831: Effectiveness of Low Dose Aspirin in Decreasing the Chance Getting Stomach and Intestine Cancer
Official title: Effectiveness of Low-dose Aspirin in Gastrointestinal Cancer Prevention - Hong Kong
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Gastrointestinal Cancer
Keywords: Esophageal cancer
Gastric cancer
Colorectal cancer
Lead sponsor: Bayer
Sponsor class: INDUSTRY
First posted: 2019-09-09
Enrollment: 99999
Sex: ALL
Minimum age (years): 40
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients aged ≥ 40 years who received low dose aspirin (75-300 mg) or paracetamol between 1st January 2004 and 31st December 2008 will be identified from CDARS (Clinical Data Analysis and Reporting System). CDARS is an electronic clinical database which is managed by the Hospital Authority (HA). More than seven million Hong Kong citizens have access to public healthcare services provided by HA.

Brief summary: In this study, researchers wanted to learn more about the effect of Aspirin taken as low dose (75 - 300 mg) in preventing stomach, colorectal and esophagus cancer. The researchers were interested in the effect by duration of aspirin use and the effect on the time since aspirin intake has been stopped in preventing stomach, colorectal and esophagus cancer. In addition, the study also looked into the time patients survived after being diagnosed (survival rate) with cancer and number of cancer patients who died (case fatality rate). The study was based on an electronic database managed by the Health Authority in Hong Kong containing anonymized clinical information of patients living in Hong Kong.


Eligibility criteria: Inclusion Criteria:

- Received prescription of either low-dose aspirin (75-300 mg) or paracetamol monotherapy during enrolment period.

Exclusion Criteria:

* Received prescription of aspirin monotherapy or combination one year prior to the index date
* Recorded diagnoses of any type of cancer before the index date
* Recorded procedures of colectomy, gastrectomy prior to the index date
* Age \< 40 years

Primary outcomes:
measure: Incidence rate ratio of colorectal cancer among users of low-dose-aspirin (exposed) and users of paracetamol monotherapy (non-exposed)
timeFrame: Retrospective analysis between 1st January 2004 and 31st December 2008
measure: Incidence rate ratio of gastric cancer among users of low-dose-aspirin (exposed) and users of paracetamol monotherapy (non-exposed)
timeFrame: Retrospective analysis between 1st January 2004 and 31st December 2008
measure: Incidence rate ratio of esophageal cancer among users of low-dose-aspirin (exposed) and users of paracetamol monotherapy (non-exposed)
timeFrame: Retrospective analysis between 1st January 2004 and 31st December 2008
Secondary outcomes:
measure: Duration of aspirin use
timeFrame: Retrospective analysis between 1st January 2004 and 31st December 2008
measure: Risk of colorectal, gastric and esophageal cancer after discontinuation of aspirin use
timeFrame: Retrospective analysis between 1st January 2004 and 31st December 2008
measure: Case-fatality and survival rate
timeFrame: Retrospective analysis between 1st January 2004 and 31st December 2008
Other outcomes:
Locations:
city: Hong Kong
country: Hong Kong
facility: University of Hong Kong
Study officials:
References: