Doctor holding endoscope before gastroscopy .
so they could be very health conscious people who exercise , don ’ t smoke , don ’ t excessively drink alcohol , and they also get a colonoscopy ,” he added , meaning that some of the observed reduction in colorectal cancer risk might be due to their healthy lifestyle , a factor that lowers the chances of developing cancer , instead of undergoing a colonoscopy .
This potential bias is a key reason the gold standard of medical evidence is randomised controlled trials , where two groups of participants are randomly assigned to receive different interventions to accurately measure any potential benefits from the treatment or procedure under testing while reducing the effects from other factors .
“ There should be high-quality evidence about the benefits and the harms of any medical intervention before it is implemented . And usually what you define as high-quality evidence is randomised trials , so almost 20 years ago we decided to do a randomised trial on colonoscopy because there was no randomised trial at that time ,” Dr Michael Bretthauer , a gastroenterologist at Oslo University Hospital , told �lo�al �ealth �sia��aci�c .
He led the NordICC study , during which 95,000 people in Norway , Sweden , Poland , and the Netherlands were either invited to undergo a colonoscopy or no colorectal cancer screening to understand whether the procedure had any benefits in terms of colorectal cancer prevention and mortality .
The results showed that 1.2 percent of the people in the no-colonoscopy group developed colorectal cancer after 10 years , while the percentage dropped to 0.98 for those who did undergo the procedure — an 18 percent reduction .
“ If you think that ’ s a lot or you think that ’ s very little , that ’ s up to everybody to decide ,” said Dr Bretthauer . “ For the risk of death , there was no significant difference , but we really didn ’ t expect that either because it ’ s a little bit too early to see that up to 10 years .”
Considering the evidence from other research , like cohort studies , as well as the fact that colonoscopy was already a standard colorectal cancer screening method in several countries once the results from NordICC were published in 2022 , these were disappointing findings .
However , experts cautioned that some factors might have skewed the NordICC results against colonoscopy .
For instance , only 42 percent of the people invited
GlobalHealthAsiaPacific . com ISSUE 2 | 2024
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