Marie Granberg's elderly father Mario was given last rites before a 2005 heart transplant, but he survived the surgery, as well as numerous fainting spells and cardiac arrests, always bouncing back and astounding his doctors.
"He is unbelievable -- I can't explain what he's been through," Marie Granberg told ABCNews.com.
But now the biggest challenge for the 74-year-old former stevedore from Staten Island has been finding a trained home caregiver so his wife can keep working and pay their bills.
He requires 24/7 care not covered by Medicare, and the family has gone through multiple aides, many of them nice, but not skilled.
"My mom had to train them," said Granberg, 45, who works as a paraprofessional. "She is exhausted."
One of the caregivers couldn't even change his diaper properly.
"She put it on backwards," Granberg said. "She actually had turned it over on the glued section and it adhered to his butt."
Another time, her mother came home on her lunch hour and found a young aide outside talking on her phone, while her father languished alone indoors.
"She looked about 18 and couldn't handle him," Granberg said.
Now, a study from Northwestern University finds that agencies that hire caregivers to work with the elderly rarely require or provide training. And, more troubling, many fail to do national criminal background tests or drug testing.
Federal rather than state background checks ensure that criminal offenders -- sexual or otherwise -- can't move between states to find work.
The study, which was published July 13 in the Journal of American Geriatrics Society, found that some agencies even recruit from Craigslist and lie about the qualifications of caregivers who will be paid to work in the home, putting those who are most vulnerable at risk.
"My patients are mostly in their 80s, 90s and 100s and so many have dementia and caregivers," said lead study author Dr. Lee Lindquist, a geriatrician and associate professor of medicine at Northwestern University Feinberg School of Medicine.
"Some are doing an outstanding job and the seniors look perfect," she said. "Others have pressure ulcers and are losing weight, depressed and falling apart. The caregivers are popping gum and playing with their iPhones and could care less."
People have a "false sense of security" when they work with an agency, according to Lindquist. "It's kind of like the wild west -- anybody from a plumber to an architect can set up shop. It's getting worse and it's scary because more people want to stay in their homes longer and it's the best place for most seniors."
More than 12 million Americans receive home health care from 33,000 providers, according to the National Association for Home Care and Hospice.
Nursing homes are regulated because they accept Medicare dollars, but regulations on home care varies from state to state, according to Lindquist.
"It's a private pay market," Linquist said. Patient families must pay between $25 and $50 an hour for in-home care, and but the agencies take a large chunk, leaving the aide with an average of $7.25 an hour. Private aides, without any middle-man, make $15 to $20 an hour.
Northwestern researchers interviewed 160 agencies, posing as a person who needed a home caregiver and asking about hiring, screening, training and competency assessment.
Only 55 percent of the agencies said they did a federal background check and only one-third said they did drug testing, according to the researchers.
Most agencies relied on self-reporting of experience and only one-third tested applicants for skill competency and waited for "client feedback," the study found.
"How do you expect a senior with dementia to identify what the caregiver is doing wrong?" Lindquist asked.
Jenn, a 38-year-old home caregiver from New Hampshire, who has worked for several agencies and is now with a private home care group, said that in her experience, the study findings are largely true.
"In all my jobs, I have never been drug tested and only once did they do a criminal background check," said Jenn, who did not want to reveal her last name for fear of reprisals from her boss. "I was quite surprised for this line of work that someone would not want to know that."
In her current position, looking after a 93-year-old man with dementia, "I was hired before I even offered up my references and I don't know if they ever checked. She basically wanted to get the position filled. I gave her the information I had, and I was hired on the spot."
Jenn said there had been no formal training. No health care is provided and she makes $15 an hour.
"Since I was hired, I have physically seen [her boss] three times," she said.
"In the past I was CPR trained and have Zen Buddhism and mindfulness coping skills," Jenn said. "I am confident in my abilities, but I am not certified."