I noticed that between the year 2003 and 2005, there is a steep drop in the percent of men screened with a PSA ever. The comparability tab suggests that there are little or no comparability issues but I remain skeptical that this drop is a real change.
Does anyone have an explanation for this difference?
This change can be explained by the change in the universe between 2003 and 2005. In 2003, the universe was: “male sample adults age 40+ who ever heard of PSA test or refused knowledge of PSA test.” While in 2005, the universe was, “male sample adults age 40+.” These notes can be found on the Universe Tab.
I hope this helps. Let us know if you have any further questions.