Kroger offers jobs to 14-year-old candidates who have valid work permits. Some positions at Kroger do require workers to be older, however. For example, a person must be at least 18 to work as a butcher or to have a job that requires handling tobacco.
The main difference when it comes to nurse practitioner vs physician assistant schooling is that there are a more limited number of accredited schools for physician assistants in the US, currently a little over 160, compared to schools for nurse practitioners which there are over 800.
The gender difference documented in the 2013 survey is linked to the demographics of the professions. Of the 2,889 nurse practitioner respondents, 90% were women and 10% were men. Of the 951 physician assistant respondents, 42% were men and 58% were men.