I have a couple of answers to this question. I live in the US and I am lucky enough to have pretty decent health insurance. Because of that I visit the doctor at least once a year for a regular checkup. It actually ends up being twice because at the first appointment she orders all of the blood work she wants me to have done and then at the second appointment, we go over all of the results.
I am also unlucky enough to have been diagnosed with Cancer a year or two ago. I am in remission now, but I still have to go to the doctor once a year to have them check me over and make sure it didn't spread or isn't coming back. I think at a minimum, everyone should try to visit the doctor at least once a year and never be afraid to visit when you are sick.
Worrying about how you will pay for it isn't worth the cost of your health. They have debt forgiveness and payment plans you can get on. You have to be healthy to work though.
Usually, I do medical check up twice in a year. However, there is no specific law that states when to do or not do medical check up.
I believe it's more about individual differences and heath conditions than anything else.
Humans ought to visit their Physician as regular as possible for routine medical check up and diagnosis. This is necessary as the human system, like every other machine undergoes systemic degradation gradually whether engaged or otherwise!!
But how often do folks do it?? It varies according to individuals idiosyncrasies and nuances. Some as often as monthly; others annually; others could be bi annually. It could even be as often as daily to those who maintain personal physician in their payroll!
But your sincerely does not adhere to any of such routine. He does it as often as instinct and prompts dictates.
It's unusual to do a general checkup in the Netherlands. I only had one about ten years ago as a special service of my insurance company. The general attitude is that going to the doctor when you're healthy could lead to unnecessary treatment, which would be bad for your health. And because of the way that health care is budgeted, you're encouraged to stick to one topic during a doctor's visit. This is one of the areas where a pretty good health care system could be better.