When I was a first-year medical student, the term morbidity was brand new to me, and I have to say it seemed pretty simple to understand. Mortality is death or the rate of death from a given condition, and morbidity is all of the other negative aspects of a medical condition. Another definition is the rate of a specific disease in a given community. Still, as I have practiced medicine for 30 years now, I have come to have much more respect for this simple term, and all of its subtle and not so subtle aspects.
Almost every decision I make in the office every day is related to trying to minimize both mortality and morbidity, and at the same time almost every choice I make has the potential to cause morbidity and sometimes mortality. Nearly everything we do in life is really to improve our odds. We cross the street when the signal says Walk, knowing that the chances of being hit by an auto are much lower than if we cross when the signal says Don’t Walk. We brush our teeth twice a day to reduce our chances of having a cavity, but have no guarantee that we won’t need a filling at the dentist. We treat patients with acute appendicitis knowing that they are less likely to die of sepsis (mortality) or to have a long miserable hospitalization with intra-abdominal abscesses (morbidity) than if we choose not to subject them to surgery. Still, they could die of an anesthetic complication, but the overall odds favor appendectomy.
Frequently, though, the decisions are much less straightforward and more nuanced than the appendectomy example. The issues with PSA testing are really more about morbidity than mortality. Men seem to fear prostate cancer more than most other health concerns. PSA testing can clearly find and diagnose many asymptomatic prostate cancers. Unfortunately, it is becoming apparent that if there is any reduction in mortality from these early diagnoses, some would argue from this overdiagnosis, then it is very tiny. If you accept that there is not much reduction in mortality from PSA screening, then the issue boils down to morbidity. Is there more morbidity related to treatment of these cancers that were diagnosed long before they would ever become symptomatic, or is there more morbidity from the cancers after they become symptomatic that is avoided by pre-symptomatic diagnosis and treatment? The consensus of many experts is that there is more morbidity from the diagnosis and treatment, and that, therefore, we should not be doing PSA screening. We are likely causing more urinary incontinence, impotence, radiation therapy complications, and emotional angst of being a cancer patient by these pre-symptomatic diagnoses than we are avoiding morbidity from advanced prostate cancer.
Often the decisions faced by physicians and their patients are less dramatic but no less challenging. Look at acute sinusitis. There is a lot of evidence suggesting that acute sinusitis of less than 10 days' duration usually resolves without antibiotic therapy in about the same number of days and with about the same severity of symptoms as with antibiotic therapy. The morbidity related to an episode of acute sinusitis that has not been present long is therefore about the same with or without antibiotic therapy. Antibiotic therapy itself can lead to significant morbidity, both the individual treated and to the larger community. Antibiotic complications like C. difficile related pseudomembranous colitis is becoming more common and antibiotic resistant. So physicians face the challenge of convincing patients who have been treated for their sinusitis with antibiotics for years and usually get well within days of treatment (as they would usually without treatment) that they are better treated with saline nasal rinses, analgesics and tincture-of-time.
These are just a few of the issues we face daily in considering the morbidity of one choice vs. another. Really most of what we do deals with morbidity, not mortality. Maybe the MMWR has it right in calling their weekly newsletter the Morbidity and Mortality Weekly Report, and not the Mortality and Morbidity Weekly Report. Most important things first, right?