Hello aspirant!!

You can choose USA from the above mentioned countries. Since, the work load for the health profession is comparatively lower when compared to other places and  there are many hospitals and private hospitals are also somewhat more than UK. If you take UK there are only few hospitals and they are public hospitals. So there will be more people getting admitted on the hospital eventually the work load is also more in UK and other countries as well. Usa is good in both aspects of salary and working hours.

All the best!!

Stay safe!!