Someone sufficiently curious and industrious could probably sleuth how/when it became a thing for radiologists—or, indeed, physicians in general—to document “pertinent negatives.” That is, diagnostic signs that are specifically not present and whose absence narrows the field of pathological possibilities.
I am not that someone. I’ve got just enough time and energy for my day-job, this little ol’ blog, and an occasional snippet of a personal life.
However, I can engage in conjecture on the matter. Docs being detectives of a sort, it makes perfect sense that they should take note of all potential clues—both positives and pertinent negatives—in seeking answers.
At some point, this went being a thing that went on in the mind of a physician (perhaps aided by notes she was jotting to keep track of things for herself) to something that he was expected/required to put in a written record for all to see.
One of the basic rules of medical documentation, we’re all told sooner or later, is “If you don’t document it, you didn’t do it.” Regarding the recognition of pertinent negatives, it somehow also became the case that “If you don’t document it, you didn’t think it.”
By the time I was going through medical education and training, pertinent negatives were introduced as one of the basic facts of life. Documenting them was just something you were supposed to do.
And not just the pertinent ones: You were also supposed to list a bunch of other things, however irrelevant (or impertinent? Interesting double-meaning there) to the situation at hand.
Doing a physical exam on a patient who’s being admitted for now-resolved chest pain? You’d better document that rectal exam, intern. Reading a CT for right lower quadrant tenderness? You’re remiss if you don’t make a point of saying the spleen is normal, in its remote left upper-quadrant domain.
The thing about such “that’s just how things are done” matters is that it’s all too easy to never really think about why they’re done that way. Or, if reasons exist at all, whether they’re good ones. If they’re embedded deeply enough, daring to raise questions about them can generate some pretty strong emotional, even irrational responses. People get uncomfortable when their accepted worldview is called into question.
Writing about this in a blog rather than speaking about it in an auditorium, I can only imagine such responses from readers when I pose the question: Is there a good reason to doggedly mention every anatomical structure on an imaging-study, no matter how normal or unrelated to the clinical issue at hand?
Suppose we take two Board-certified radiologists, of comparable experience and accuracy-rate, and have them independently read the same CT. Both take the appropriate amount of time and effort in reviewing the study, and both conclude that it is entirely normal.
One of them reports it out with a highly-structured, templated report that has over a dozen different section-headings (“LIVER: Normal. SPLEEN: Normal. PANCREAS…” etc.), taking up an entire page in the process. The other rad simply says: “This CT of the abdomen and pelvis is normal.” Did either rad do a better job than the other? Note that the question is not who might have appeared to do better.
Same scenario, but now the CT has some abnormalities. Again, both rads correctly identify what’s amiss. The first rad dutifully reports the abnormalities in their appropriate sections in her templated report, with all of the other “Normal” sections still surrounding them. The clinician has to sift through it all to make sure he finds the relevant stuff.
The second rad clearly and succinctly states the abnormalities, perhaps itemized in a short list, followed by “All other imaged anatomy of the abdomen and pelvis is normal.” Again, did one of them do a better job?