The Massachusetts Hospitalization Puzzle

For everyone dealing with the coronavirus, there is both a societal and personal calculation. The societal calculation revolves around the enormous global and national costs of the pandemic – the staggering number of illnesses, hospitalization, and deaths, as well as the economic toll – massive unemployment, shuttered businesses, and food insecurity.

But there is a personal calculation with which most people wrestle. How likely am I or the people close to me to get sick; and if they get sick, how sick will they be? What are the odds that they will be hospitalized, or obviously even worse, how likely are they to die? This calculation clearly is highly dependent on personal circumstance – age, type of work, underlying health conditions, etc. But a starting point for understanding this is the number of people hospitalized from the coronavirus. (Obviously, this is an incomplete measure of severe illness, as many ill people in long-term care are never hospitalized regardless of how severely ill they become). And here, the available information in Massachusetts is confusing.

The Commonwealth has published a running total of the number of confirmed and suspected Covid-19 cases, total hospitalizations, and total deaths through time. (According to the Dashboard, this information comes from the Bureau of Infectious Disease and Laboratory Sciences). However, when the state changed the definition of probable cases earlier this month, they restated the cumulative number of hospitalizations without providing the details of the historical revisions – unlike what they did for cases and deaths. The number of confirmed and suspected hospitalizations dropped from 13,386 on September 1 to 13,295 the next day.

Fortunately, there is another source of hospitalization data – that provided by hospitals themselves and submitted to the state Department of Public Heath and federal government. Hospitals report both the number of patients currently hospitalized for Covid, and the number of new hospitalizations. Unfortunately, these data on new hospitalizations do not track the data collected by the state – in fact, the number of new probable case hospitalizations reported don’t make much sense if taken at face value.

For the week ending September 3, hospitals in Massachusetts reported an average of 312 patients hospitalized with Covid, an average of 19 new confirmed case admissions, and an average of 126 suspected case admissions, for a total of 145 new admissions. These statistics do not square with what we know about the hospital stays of Covid patients. Since the only way patients leave the hospital is if they are discharged or die, this would imply an average hospital stay of roughly two days, much shorter than what one would expect.

It is unclear exactly what these suspected hospital admissions are tracking, but the definition seems overly broad. According to the dashboard, these suspected cases “are those with symptoms who have not had a test result yet”. Perhaps many of these originally suspected cases turn out to not be Covid patients at all, or there is something else not transparent about this reporting.

However, the number of confirmed hospital admissions does closely track the number of newly hospitalized cases reported by the state up to the point at which the probable case definition was changed, as shown below. Both figures also reinforce the idea that the state has been in rough equilibrium for about the past five or six weeks (this is true for cases, hospitalizations, and deaths), with relatively low case and hospitalization rates.



Massachusetts Reporting Change: Probable Cases

On September 2, Massachusetts once again changed its coronavirus reporting – this time changing the definition of “probable cases”. According to the Massachusetts Dashboard “The previous case definition defined probable cases as individuals: with a positive antigen or serology test AND symptoms or likely exposure; with COVID-19 listed as an underlying or contributing cause of death on a death certificate; and with appropriate symptoms and likely exposure.”

However, “The new case definition updates the clinical criteria associated with COVID-19; defines probable cases as individuals: with a positive antigen test, with COVID-19 listed as an underlying or contributing cause of death on a death certificate, or with appropriate symptoms and likely exposure .” Furthermore, “the criteria indicating likely exposure are now restricted to known contact with a case or association with a specific outbreak. Individuals with positive serology (antibody) tests have been placed in a new suspect category which is not reportable to CDC.”

The Commonwealth indicates that the new reporting standard is more objective, is able to be more consistently applied through time, and brings Massachusetts’ reporting of probable cases more in line with the reporting standards of other jurisdictions. (Note that not all jurisdictions even report probable cases).

Significantly, all of the prior reporting on probable cases, hospitalizations, and deaths has been adjusted and backdated for this change. What are the ramifications of this? First, the Commonwealth reduced the number of probable cases substantially – from 9,755 under the old standard to 1,705 under the new standard (a reduction of 8,050).

The chart below shows the weekly change in probable cases over time. Most of the cases dropped were from May, when the pandemic was raging in Massachusetts. However, a substantial number of cases from June through August were also eliminated.

The number of probable deaths from Covid19 also dropped, but much less substantially – from 233 to 207 (26 deaths). The eliminated probable deaths are spread relatively uniformly over time. Ironically, however, the first death reported in Massachusetts, which occurred on March 10, was a probable case that was eliminated. I have adjusted my reporting statistics where possible to reflect these changes in cases and deaths.

The other consequence of this change is that it impacts how Massachusetts stands relative to other states in the case horse race (a horse race nobody wants to win). Early on, Massachusetts was third in the country in the number of cases, trailing only New York and New Jersey. As our case rates dropped substantially, and the pandemic spread to the Sun Belt, we had dropped in the rankings to 13th in the total number of cases, and 17th in cases per capita (per the worldometers aggregation site We are now ranked 16th in total cases and 22nd in cases per capita.

Unfortunately, our per capita death ranking remains unchanged – we have the 3rd highest per capita death rate, trailing (once again) only New York and New Jersey.

Data Update

Massachusetts Data Update September 1, 2020

Massachusetts appears to be in Covid equilibrium. Test positivity rates have declined somewhat over the past four weeks, but remain the highest in New England. Testing has ramped up in the past month (perhaps in part because students and some teachers are returning to school at all levels).

An interesting statistic to note is the shift in the composition of those being tested.  Over the past week, almost half of tests performed have been for people who have been tested before.  While this seems to be partly an artifact of more rapid turnaround time for repeat testers, there clearly appears to be increased emphasis on preventative testing. In fact, over the last four weeks the number of repeat tests has increased by almost 300%, compared to an increase of  57% for people being tested for the first time. The shift to  repeat testers are in part the driver of the low overall test positivity rate (currently 1.0%) as they have a much lower positivity rate (currently 0.3%) than people tested for the first time (currently 1.5%). Most of them are being tested asymptomatically.

Massachusetts Testing Statistics
7 Day Trailing Average Results
September 1, 2020
Testing Statistic   Current 7 Days Ago 4 Weeks Ago
Test Positivity Rate (Individuals)   1.6% 1.5% 1.9%
Test Positivity Rate (Include Suspected)   1.7% 1.7% 2.5%
Test Positivity Rate (All Tests)   1.0% 1.1% 1.6%
Test Positivity Rate (New Tests)   1.6% 1.5% 1.9%
Test Positivity Rate (Repeat Testers)   0.3% 0.5% 1.0%
Percentage Repeat Testers   48.5% 39.4% 29.5%
New Tests (Lagged 1 Week)   19,426 17,453 12,354
All Tests (Lagged 1 Week)   32,038 25,356 17,138

Hospitalization figures have remained stubbornly consistent for over a month.  On July 22, there was a large drop in the number of Covid hospitalizations from 532 to 351, and they have remained fairly steady since then.  (The large drop may a result of the federally-mandated  switch in hospital reporting from the CDC to HHS). 

The number of ICU and intubated patients have followed roughly the same pattern – there were 49 patients in the ICU and 29 intubated patients in hospitals on July 23, essentially the same as today.  The number of patients newly admitted to the hospital has remained steady of the past six weeks as well.  While covid-19 is well under control in Massachusetts, it remains nowhere near being extinguished.

Massachusetts Hospitalization Statistics

September 1, 2020


Hospitalization Statistic



7 Days Ago

4 Weeks Ago


Covid Patients Hospitalized





Covid Patients in ICU





Covid Patients Intubed






7-Day Trailing Average New Patients





Not surprisingly, death statistics in Massachusetts roughly track  hospitalization and critcal care statistics. There has been little change in the number of reported deaths (confirmed and suspected) over the past month.  The 7 day trailing number of reported deaths hit 16 on July 16, and has been in a tight range since then.  This reinforces the case that we are in equilibrium.

What remains striking is the high percentage of deaths in long-term care facilities, which has been almost 65% over the course of the pandemic in Massachusetts (and almost 72% of deaths since June 1).  There is no sign that this troubling trend is abating.

The case statistics are a function of both testing and test positivity rates.  The number of cases (confirmed and suspected) of Covid remains high, but this is primarily a function of increased testing, as positivity rates are at or near the all time low.

Massachusetts Reported Case and Death Statistics

7 Day Average Trailing Results

September 1, 2020





7 Days Ago

4 Weeks Ago


Total Deaths





Deaths in Long-Term Facilities





Percent from Long-Term Care






Total Cases Including Suspected