Christakis NA and Iwashyna TJ.The health impact on families of health care: a matched cohort study of hospice use by decedents and mortality outcomes in surviving, widowed spouses . Soc Sci Med2003; 57: 465-475 .
2.
Christakis NA and Allison PD.Mortality after the hospitalization of a spouse . New Engl J Med2006; 354: 719-730 .
3.
Hanks GW , Rose NM , Ahern GW , et al.Analgesic effect of morphine tablets . Lancet1981; i: 732-733 .