What is the theme in Where Is the Mango Princess? by C. E. Crimmins?

The main theme is struggles with the HMO. Though stuck in a foreign country, Cathy felt Alan was better off having his injury in Canada than in the United States, and she even considered moving the family to Canada before deciding to go back to their hometown of Philadelphia. This was because Canada had a national health care system, and the United States' health care system was comprised largely of private corporations.