Note: This dashboard contains the results of a predictive model. The author has tried to make it as accurate as possible. But the COVID-19 situation is changing quickly, and these models inevitably include some level of speculation.

Summary for the United States on 2020-04-05:

Reported Case Count: 305,614

Predicted Case Count: 377,108

Percentage Underreporting in Case Count: 19.0%

COVID-19 Case Estimates, by State

Definition Of Fields:

  • Reported Cases: The number of cases reported by each state, which is a function of how many tests are positive.
  • Est Cases: The predicted number of cases, accounting for the fact that not everyone is tested.
  • Est Range: The 95% confidence interval of the predicted number of cases.
  • Ratio: Estimated Cases divided by Reported Cases.
  • Tests per Million: The number of tests administered per one million people. The less tests administered per capita, the larger the difference between reported and estimated number of cases, generally.
  • Cases per Million: The number of reported cases per on million people.
  • Positive Test Rate: The reported percentage of positive tests.
Reported Cases Est Cases Est Range Ratio Tests per Million Cases per Million Positive Test Rate
state
NY 113704 128438 (117906, 155233) 1.1 14579.4 5844.9 40%
NJ 34124 40562 (35807, 51982) 1.2 8483.9 3841.8 45%
MI 14225 20079 (15748, 32313) 1.4 2615.2 1424.4 54%
CA 12026 17017 (13324, 25765) 1.4 2877.6 304.4 11%
LA 12496 14359 (13002, 17347) 1.1 12583.5 2688.0 21%
FL 11111 14273 (11891, 20064) 1.3 4752.2 517.3 11%
MA 11736 13760 (12281, 17790) 1.2 9981.9 1702.7 17%
IL 10357 13611 (11387, 21125) 1.3 4228.4 817.3 19%
PA 10017 12698 (10776, 18243) 1.3 5470.2 782.5 14%
TX 6110 9193 (7056, 15169) 1.5 2198.6 210.7 10%
GA 6160 8945 (6993, 14765) 1.5 2476.5 580.2 23%
WA 6966 8019 (7206, 10369) 1.2 10847.0 914.8 8%
CT 5276 6552 (5637, 8749) 1.2 6178.7 1479.8 24%
IN 3953 5588 (4472, 8719) 1.4 2941.1 587.2 20%
CO 4173 5571 (4515, 8807) 1.3 3832.6 724.6 19%
OH 3739 5052 (4074, 7765) 1.4 3582.1 319.9 9%
MD 3125 4178 (3409, 6409) 1.3 4236.1 516.9 12%
TN 3321 4131 (3505, 5602) 1.2 6060.9 486.3 8%
VA 2407 3444 (2689, 5681) 1.4 2525.0 282.0 11%
NC 2402 3270 (2670, 4899) 1.4 3696.9 229.0 6%
MO 2291 3009 (2498, 4351) 1.3 4057.9 373.3 9%
WI 2112 2741 (2271, 3910) 1.3 4460.5 362.7 8%
AZ 2019 2705 (2202, 4148) 1.3 3731.4 277.4 7%
SC 1917 2594 (2111, 3891) 1.4 3557.0 372.3 10%
OK 1159 2523 (1603, 5741) 2.2 637.1 292.9 46%
AL 1580 2374 (1796, 4129) 1.5 2213.5 322.2 15%
NV 1742 2207 (1880, 3165) 1.3 5247.5 565.6 11%
MS 1455 2157 (1683, 3645) 1.5 2213.6 488.9 22%
UT 1428 1691 (1497, 2121) 1.2 8747.2 445.4 5%
ID 1013 1296 (1096, 1883) 1.3 4963.4 566.9 11%
OR 899 1188 (989, 1780) 1.3 4133.5 213.1 5%
MN 865 1129 (936, 1677) 1.3 4507.9 153.4 3%
KY 831 1116 (903, 1624) 1.3 3485.5 186.0 5%
IA 786 1073 (881, 1663) 1.4 3245.6 249.1 8%
DC 902 1069 (945, 1370) 1.2 9122.2 1278.1 14%
AR 743 1016 (816, 1516) 1.4 3436.3 246.2 7%
KS 698 1009 (793, 1570) 1.4 2601.2 239.6 9%
RI 806 1003 (859, 1390) 1.2 6031.9 760.8 13%
PR 452 881 (587, 1842) 1.9 788.1 141.5 18%
DE 593 731 (631, 1004) 1.2 6641.2 609.0 9%
NH 540 682 (580, 977) 1.3 5519.6 397.1 7%
NM 495 602 (523, 811) 1.2 7455.1 236.1 3%
ME 456 578 (491, 818) 1.3 4868.3 339.2 7%
VT 461 544 (484, 710) 1.2 9365.5 738.8 8%
NE 321 446 (356, 660) 1.4 2780.7 165.9 6%
HI 319 379 (335, 513) 1.2 8671.7 225.3 3%
WV 282 364 (305, 505) 1.3 4288.7 157.4 4%
MT 265 332 (284, 470) 1.3 5779.5 247.9 4%
SD 212 266 (227, 373) 1.3 5905.1 239.6 4%
WY 187 237 (200, 345) 1.3 5411.6 323.1 6%
ND 186 222 (196, 288) 1.2 8145.0 244.1 3%
AK 171 204 (180, 265) 1.2 8256.5 233.8 3%

Appendix: Model Diagnostics

Derived relationship between Test Capacity and Case Under-reporting

Plotted is the estimated relationship between test capacity (in terms of people per test -- larger = less testing) and the likelihood a COVID-19 case is reported (lower = more under-reporting of cases).

The lines represent the posterior samples from our MCMC run (note the x-axis is plotted on a log scale). The rug plot shows the current test capacity for each state (black '|') and the capacity one week ago (cyan '+'). For comparison, South Korea's testing capacity is currently at the very left of the graph (200 people per test).

About this Analysis

This analysis was done by Joseph Richards.

This project1 uses the testing rates per state from https://covidtracking.com/, which reports case counts and mortality by state. This is used to estimate the number of unreported (untested) COVID-19 cases in each U.S. state.

The analysis makes a few assumptions:

  1. The probability that a case is reported by a state is a function of the number of tests run per person in that state. Hence the degree of under-reported cases is a function of tests run per capita.
  2. The underlying mortality rate is the same across every state.
  3. Patients take time to succumb to COVID-19, so the mortality counts today reflect the case counts 7 days ago. E.g., mortality rate = (cumulative deaths today) / (cumulative cases 7 days ago).

The model attempts to find the most likely relationship between state-wise test volume (per capita) and under-reporting, such that the true underlying mortality rates between the individual states are as similar as possible. The model simultaneously finds the most likely posterior distribution of mortality rates, the most likely true case count per state, and the test volume vs. case underreporting relationship.


  1. Full details about the model are available at: https://github.com/jwrichar/COVID19-mortality