It's the ratio of nurses to patients! As the ratio of patients-to-nurses rises above 4 to 1, so does the postoperative death rates. For every additional patient above four a nurse is expected to tend, there is a 7% increased risk of death. Patients are more likely to suffer from such complications as urinary tract infections, and pneumonia and more likely to die from such treatable conditions as gastrointestinal bleeding. This was reported in the AARP Newsletter.
There is actually a 126,000 person shortage of nurses. This means when the ratio is higher, you're going to be having nurses who are overextended and tired.
So what can you do? If you are doing elective surgery, check out the nursing staff ratio in advance. Have a family or friend at your side during the hospital stay. Have them act as an advocate for you. Write everything down including questions to ask your doctor and nurses. Double check if there's a change to any of your medications or IV fluids.