A study from the Annals of Internal Medicine suggests that doctors are not always aware of test results of patients discharged from the hospital:

The researchers examined the medical records of 2,644 patients at two hospitals from February through June 2004. The hospitals were not identified, but the researchers said they are both academic centers in Boston.

All of the patients were in the care of hospitalists, who are doctors based in hospitals. About 41 percent of the patients had test results due when they left the hospitals, Roy said.

Forty-three percent of the time, post-discharge test results were abnormal; in about 10 percent of cases they suggested serious problems requiring doctors to take action, according to the study.

The researchers surveyed the appropriate hospital doctors on 155 of the most worrisome tests. Many doctors failed to respond to the survey, but those who did provided information on what they recalled about 105 of the tests, according to the study.

More than 60 percent of the time, the responding doctors said they didn't know about the test results; one-third said they didn't even know the tests had been ordered, the study authors said.

I can give a first-hand account why this happens:

1) Too many tests are being ordered. When a patient comes into the ER, a typically "ER panel" of bloodwork is drawn no matter what the chief complaint is. This can include a urinalysis, blood count, metabolic panel, liver function tests, cardiac enzymes etc.

2) Too many doctors are ordering tests. Many cases will have various consultants evaluating the patient - be it a cardiologist, pulmonologist, gastroenterologist etc. Each consultant will order their own specific, mutually exclusive brand of tests. Some will expect the primary care physician to follow-up, some will do it themselves.

3) Tests take too long to come back. The majority of hospital stays are short, lasting 1-3 days. Tests such as blood cultures, pathology results or send-away tests sometimes takes up to 1 week to return. The patient will often be discharged before then.

4) Too many doctors taking care of the patient. Before, a single doctor will follow the patient in the hospital as well as in the clinic. Now with the advent of hospitalists, more cooks are stirring the pot. This increases the risk of information falling through the cracks as the patient is handed off from one doctor to the next.

Bottom line: Better communication is needed between specialists, hospitalists, and primary care. (Dotinga, "Doctors Don't Always See Hospital Test Results", Forbes, Jul.18; Roy et al. "Patient Safety Concerns Arising from Test Results That Return after Hospital Discharge", Ann Int Med, Jul.19)