Four out of five doctors agree that they don’t need scans to make the right diagnosis.
It’s an old-fashioned concept frequently discussed among ACP members, but the history and physical combined with basic tests is way more important to diagnosis than ordering scans and advanced tests. A recent research letter in the Archives of Internal Medicine makes the case.
In the letter, Israeli researchers described a prospective study of 442 consecutive patients admitted from the emergency department in 53 days.
A senior resident examined all patients within 24 hours of admission (mean=14), including a history, physical, and review of ancillary test findings done at the emergency department, such as blood and urine tests, electrocardiography, and chest radiography. The resident also reviewed additional tests such as troponin, C-reactive protein, and international normalized ratio, as well as computed tomography or ultrasonography. Finally, medical charts from previous admissions and all medications and vital signs were reviewed.
The senior resident then determined a main diagnosis and indentified what helped her reach it. Her diagnosis was sealed. Hospital physicians, either hospitalists or medical educators with more than 20 years of experience, repeated the process (mean exam time was less than 25 minutes), and they also sealed their diagnoses. At least one month after discharge, the senior resident verified the patient’s final diagnosis and called the patient’s primary physician.
The senior resident was correct in 354 of 442 diagnoses (80.1%), while the hospital physicians were correct in 373 patients (84.4%). They made identical correct diagnoses in 327 cases (73.9%). Both were wrong in 42 patients (9.5%) (P=.04).
For the resident and the hospital physicians, patient history was the key element in making the diagnosis. The physicians could make the correct diagnosis on history alone in about 20% of all diagnoses, or in combination with the physical in another 40%. Basic tests with or without the physical examination were key to the correct diagnosis in one-third of cases.
While the exam or basic tests alone were very seldom helpful, the physical examination doubled the diagnostic power of the history (19.5% to 39.0%). Imaging, mainly head computed tomographies, were infrequently used in the emergency department and added little to making the correct diagnoses.
“We found that more than 80% of newly admitted internal medicine patients could be correctly diagnosed on admission and that basic clinical skills remain a powerful tool, sufficient for achieving an accurate diagnosis in most cases,” the researchers wrote. 90% of all correct diagnoses were accomplished on presentation through a combination of the history, physical and basic tests. This combination correctly diagnosed three out of four admitted patients.
“Our results do not mean that sophisticated studies need not be used after admission, but they do suggest that their choice should be guided by the clinical data on presentation,” the researchers concluded.
*This blog post was originally published at ACP Hospitalist*