Study author Lindquist said she has seen examples of neglect in her own medical practice. She said she had a 103-year-old patient whose illiterate caregiver mixed up her own medications and those of the patient.
Another woman dropped 10 percent of her weight and developed bed sores because she was not being properly fed or taken out of bed.
Lindquist's study found that 84 of the agencies she contacted were no longer in business. They had slick websites, but their phones were dead.
"When they make money, they leave the industry after three to five years," she said. "Bosses change or they get out of the field.
"Most people almost try to sell a product and tell us what they thought we wanted to hear," she said.
Some cited phony tests when asked about background checks, including one agency that said it used a "National Scantron Test for Inappropriate Behavior" and an "Assessment of Christian Morality Test" -- neither of which exists, Lindquist said.
When asked about drug testing, some agencies told researchers, "Oh no, unless you pay for it."
As for supervision, only 30 percent of the agencies did a once-a-month home check.
"Amazingly, some agencies considered supervision to be asking the caregiver how things were going over the phone or when the employee stopped in to get their paycheck," Lindquist said.
To find a reputable agency, Linquist advises talking to friends and family and get "word of mouth" to get recommendations for good and bad agencies. Private duty nursing associations can also be helpful, but they represent only a small number of agencies and "cannot vet everyone."
Lindquist said ultimately, laws must change to provide more regulation of the industry, but she hopes her study will educate consumers who can put more market pressure on the bad agencies to get out of the home care business.
"We need to expect better things from an agency and a caregiver," she said.
"A lot of people spend more time picking out a car than an agency," Lindquist said. "Think about it -- this is your loved one, your mom, your dad, your grandma. That should mean something."
As for Granberg, after much trial and error, her family has finally found an excellent caregiver for her father.
"We've been through so much," she said. "But the woman we now pay, if she were ever to leave us, I don't know what we would do. She is phenomenally generous and cares about my dad -- she looks out for him."
As for the others, she said, "You try to train these people, but in reality, some of them are lazy or not trained enough or don't know how to deal with people like my dad who has so many issues."