Post-pandemic ER patients are sicker, on average.

Data snapshot from Massachusetts shows why ERs and hospitals are often drowning in demand these days.

Sometimes we forget that the “before times” weren’t exactly smooth sailing. Emergency rooms in Massachusetts were very busy in 2019 and early 2020. So, when Covid-19 hit, something strange and a little unexpected happened: We initially had fewer ER patients overall. The ones we had, though, were far sicker.

Nine months later—the first full winter after Covid-19 arrived—ER visits were back to pre-pandemic levels. But things seemed worse somehow. Why? Had we grown soft?

Nope. We had pre-pandemic ER volumes, but post-pandemic levels of sickness.

When we track ER and hospital capacity, the two main patient factors are volumes and illness severity. The latter is called “case mix.” If 10% of ER patients are admitted to the hospital (instead of discharged), that’s a favorable case mix; 30% reflects a far sicker population. The higher that quotient, the sicker the case mix.

When things get tight, there’s a genuine risk that care teams will discharge patients a bit sooner than is best—and even that patients who would be safer by being admitted to the hospital are instead sent home. Indeed, fuller hospitals tend to be sicker ones.

Recently, Inside Medicine data guru Benjy Renton showed me a dataset I’d never seen before which allowed me to run an analysis of exactly what happened to us in Massachusetts. It’s our Data Snapshot for the week. In the graphic below, each circle is the hospitalization rate (all causes) in one week.

Data: MA Department of Health. Image by Jeremy Faust and Benjy Renton. The X-axis shows proportions (i.e. 0.17=17%, meaning that for every 100 ER visits, 17 people were hospitalized).

Since the pandemic erupted, on average, more than 22.4% of all ER patients in Massachusetts have needed hospitalization. That’s well above 2019 and early 2020 levels (the “pre-times”), when the average rate was 19.6%. The changes were most extreme in the first year of the pandemic. But notice that since the second year, the averages have been creeping up, not down.

Data: MA Department of Health. Image by Jeremy Faust and Benjy Renton. PHE=public health emergency. The Y-axis shows proportions (i.e., 0.3=30%, meaning that for every 100 ER visits, 30 people were hospitalized).

Why has this been happening? It’s likely a combination of the continued persistence of Covid (albeit at lower levels), and healthcare catchup.

“Covid and catchup” means healthcare demand has increased.

What’s healthcare catchup? Think of it as increased demand for healthcare due to delayed care caused by the pandemic. For example, a bunch of cancer screenings that should have happened in 2020 didn’t happen until 2021, 2022, or even 2023. Some of these folks are now getting treatment that they likely would’ve started earlier. With treatment comes complications. With complications comes hospital admissions.

Notice, also, that the fraction of ER patients who were hospitalized swelled during Covid-19 waves (even though total ER visits often went down during those times; dramatically early on, less in the later waves). This suggests that some degree of “self-triage” occurred in the community. That matches my experience. During Covid-19 waves, it seemed to me that we saw fewer ER patients seeking treatment for things like migraine headaches. I imagine that people were still having migraines, but they just toughed it out at home, rather than coming into the ER for treatment. (It’s also possible that during Covid-19 waves, there really were fewer migraine headaches; for many, migraines are triggered by things that happen outside the home and during Covid-19 waves, people tended to stay home more.)

Nowadays, we have it all: Patients who don’t feel well—those who benefit from being treated in the ER, but who can be discharged after feeling better—and patients with complicated medical needs requiring admission (more of them, because the system is still catching up). Combine that with the continued and persistent presence of Covid-19, plus the return of other bugs like flu and RSV, and it adds up to hospitals being flexed to their max more of the time.

Back in 2019 and early 2020, our hospitals could barely keep up with demand. Adding Covid-19 and healthcare catchup to the mix has left us where we find ourselves today— longer ER waits and fuller hospitals more often.

So, if you go to the hospital and find that your wait (at any step of the process) is longer than you’d expect, now you know why: We have more patients and a higher percentage of them need complex care.

Clinicians and patients…have you noticed a difference in the ER or the hospital since the pandemic? Share your insights in the Comments section.

Thanks to Benjy Renton for curating this Data Snapshot.