The study is also looking at a complex thing like interpersonal relationships. Some people who are sick or have issues blame the people helping them. My wife gets upset I do not care enough about her issues when I am working on work, and our finances, and all our other stuff that have to be in line so that she can get the best care we can. She likes to bring up divorce even though she would be utterly fucked in that scenario. If she were married to another type of man she would be one of these statistics. Im not saying that is the only reason as I have seen sickly men act like this to.