title: Impact of HMO penetration on nurse staffing and quality.
mesh_terms: D006279:Health Maintenance Organizations; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007902:Length of Stay / Q000639:trends; D009741:Nursing Staff, Hospital / Q000600:supply & distribution*; D011787:Quality of Health Care; D014481:United States