text_1: New DNA Tests Aimed at Reducing Colon Cancer
text_2: Strengths:  Immediately, in the opening words, the story acknowledges that there is another DNA test in development that was reported on this week. It was the only one of the four stories we reviewed on this topic that made this clear. Weaknesses: It didn’t provide a meaningful comparison of the new approaches with existing colon cancer screening tests. It also has problems with how the underlying question is presented. Two examples:  “The new tests could help most people avoid colonoscopies, which are routinely prescribed for people over age 50.” – perhaps implying to the reader that evidence supports a recommendation of colonoscopy for everyone.That is not the case; there are several potential screening tests available, including other stool tests – something not mentioned in the story. “Compliance with colonoscopy is low, since people don’t want to have one, and the overall cost per detection is high because most people are healthy, and even colonoscopy misses many tumors in the upper part of the intestine.” This sentence has a lot of information, but is also somewhat misleading. Use of colonoscopy is actually pretty good, and most people who don’t have one have never been asked, calling into question that people “don’t want to have one.” The cost effectiveness of colonoscopy vs. other screening techniques is a complex question, but suffice it to say that the new technology being studied is not likely to be more cost-effective overall (previous stool DNA tests have performed much worse (higher costs, lower efficacy) than colonoscopy in modeling studies. This topic is really about when we should pay attention to evidence about a new diagnostic test and how we should evaluate diagnostic tests in comparison with one another- a topic that is often inadequately discussed in both medicine and journalism.