Look at the area of coverage ! If you are International Traveller then ok an International Policy is a good idea BUT if you only stay in Thailand or lets say just go to the European Union occasionally , then it pays to look for a "Thailand only policy" as the premiums for International Policies increase substantially for cover in USA/Europe etc and for things you might never need or are not applicable ( ie repatriation of body etc )
Then, if you go to Europe you can just take a Schengen insurance policy for the period there . As always , look for a reputable insurer underwritten by a reputable body and read the small print .