Yeah, unnecessary testing as CYA because of the danger of malpractice suits IS a factor for why healthcare is so expensive in the USA relative to other industrialized countries...but it's a small factor. It's no mystery why this would be a big issue with doctors but it doesn't have a lot to do with how expensive healthcare is.
By far the biggest factor for why healthcare is so expensive in the USA relative to nearly all other industrialized countries is that we don't have single payer which would allow us to negotiate prices much more aggressively with healthcare providers, drug makers, and medical device manufacturers.
The goofy-looking non-GB'er in the video below explains this better than I can:
Ok I bite, who should the single payer be....BCBS, United Healthcare, Aetna, or aghast the government. Lets see, do away with private insurance companies and everything is run by the government. Brilliant, you immediately put millions of Americans out of work who work for the private insurance companies. Second, when has the US government ever run a business responsibly without going into debt. Who is going to pay for it. Fifty percent of Americans have no skin in the game; they do not pay taxes and in fact get refunds. Ok, tax the rich...great. What happens when they run out of money. Now who is going to pay for Universal Healthcare.
Universal healthcare will only work if every individual in this country has skin in the game. Moreover, self responsibility needs to come into play. How are we going to pay for ove 300 million Americans when the 24 milion working Americans don't have a job....don't believe the BS jobless reports given monthly as they do not count those who have quit looking for a job. The real unemployment number is 15%. Thus, how the hell do you propose you will pay for this. Medicaid, which is state and federally subsidized is barely accepted at many physicians offices as the reimbursement fee is too low; doctors lose money caring for Medicaid patients. There are more people joining Medicaid on the ACA than those signing up for private insurance; the plan as it is unsustainable.
If you are stuck with a single payer system, they can dictate therapy as they see fit. You could be a 65 yo male with no prior history and have an infection that leads to renal failure and because of your age you may not receive a kidney transplant. You may not receive that life saving chemotherapy because it is too expensive. If you have no recourse except one insurer you are the mercy of that plan and that plan alone. I and a lot of medical professionals see a trainwreck coming.