Based on an extensive corpus of testamonials and intelligence material I have gathered, I can conclude as follows.
Generally, medical exams in schools have declined to nearly nothing in many countries. But around the world, including, UK, Germany, Norway, USA, Canada, France, certain schools seem to be elected as sites for medical research and population surveillance by a consortium of public authorities, medical companies, universities and research organizations.
In these schools the frequency, thoroughness intrusiveness and end temporal endurance of the exams have increased manifold to what was common in the 1960es, 1970es and 1980es.
Some of these schools are indeed public schools, but most are private , or schools with special curriculum, like sport and dance. Montessori schools are especially heavily involved.
The parents are mostly made to agree by offerings of free medical care for the kids, money offers or agreement of participation in the exam program is mandatory to let the kid go to that school.
Some countries or some communities within several countries has such a general authoritarien culture that these extended exam programs are done without any prior agreement. Some communities where the authorities have a hysterical approach for everything they think of as child abuse, also perform such exams to detect any symptom that might signal abuse.
In Norway, where I am from, the common exam program for kids is not very extensive. But any symptom of something with the kid not conforming to a strict standard, will result in the kid being called in to a sequence of very intimate and intrusive exams, physically and mentally, often done under general anesthesia so that neither thee kid nor the parents are fully aware of what happens.
Also Norway tend to run great projects for medical surveillance of kids, where a certain percentage of the kids in the country are called in, or one elect one specific area. Usually the parents are asked to volunteer their kid for the project, and most parents answer yes, either because the Norwegian people has been effectively brainwashed to blidly trust authorities, or because they fear revenge if they answer no.