The brother to the physician who performed the first human to human heart transplant, Dr. Christian Barnard, is the person who invented critical illness insurance. Like his brother, Dr. Marius Barnard was also a cardiac surgeon in Cape Town, South Africa. He saw that he could heal people's bodies but he could not heal the financial toll that their illness and treatment took on the lives of them and their families. Dr. Marius Barnard created Critical Illness Insurance to offset that. the first policy was issued in South African in 1983.
The first Critical Illness policy was issued in 1983 in South Africa. They have grown in popularity since that time.
A full-time broker (not a part-timer, a media person or someone not fully-licensed) will be your best resource for quotes and information.