Final answer:
Cancer is the diagnosis that accounts for approximately half of all hospice admissions, primarily because it is one of the leading causes of death in higher-income countries.
Step-by-step explanation:
The diagnosis that accounts for approximately half of all hospice admissions is cancer. Hospice care is a type of healthcare for terminally ill patients where cure-oriented treatments are not possible, and the focus is on providing comfort and dignity in death. Cancer, including all its types, is a predominant cause of death and leads to high rates of hospice utilization. While diseases like Alzheimer's, heart disease, and kidney failure also contribute to hospice admissions, it is cancer that remains the most common diagnosis, reflecting broader epidemiological trends where cancer causes twice as many deaths as cardiovascular diseases in higher-income countries.