Open Letter to IHME

May 7, 2020

Open Letter to IHME

Dr. Christopher J.L. Murray Institute Director and Professor of Global Health University of Washington

Emailed to: covid19@healthdata.org & media@healthdata.org

Dear Dr. Murray:

On May 4, 2020, IHME released the much-anticipated update to its Covid-19 model for the United States. Its estimates for the projected total number of deaths in the USA jumped up from ~65 thousand to ~130 thousand, i.e. nearly doubled.

Given the especially high interest and sensitivity of this matter, we feel it is our duty to point out an apparent inconsistency in the IHME model/data and inquire about the magnitude of the impact of these inconsistencies on your final projections.

1. Why are the numbers of actual deaths used in IHME model for the State of New York (NYS) so different from the numbers reported by Gov. Cuomo in his daily briefings [1]? The IHME actual numbers of deaths, e.g. from April 25th through April 30th, highlighted in the below simple comparison table, are 45-57% higher than the numbers reported by the Governor. Why is that? These obviously are rather huge differences!

2. The IHME released new projections on May 4th. Why are then the numbers of actual deaths not included for the three preceding days, i.e. for May 1st through May 3rd in the released model? Instead, the model uses its projected values for those days when the actual death numbers were already available!

3. Even if there were to be a three to four day lag to fully incorporating any new data into the IHME model ( which would in itself speak rather unfavorably about adaptability of the IHME model and would be seen as its big deficiency ), why would the IHME not highlight or comment on the huge discrepancy between the projected values and the actuals for those three days, i.e. May 1st through May 3rd? The IHME “projections” for those day are whopping 65-104% higher than the actual numbers of deaths reported by Gov. Cuomo!

We would think that the shortcomings outlined above should have a huge impact on both the predictions and the accuracy of the IHME model not only for NYS, but also for the entire USA because NYS happens to be such a big fraction of the USA data as far as the Covid-19 epidemic measurements go.

We have not examined other states. We just happen to notice these glaring discrepancies regarding the IHME’s treatment of the NYS data because, living nearby, we naturally watch very closely all developments in NYS.

We hope these discrepancies can be corrected promptly and prior to next release/update of the IHME model predictions.

If, on the other hand, these happen to be systemic faults or deficiencies of the IHME model, then they must clearly be highlighted as such to the general public.