Value comparison with HHS

Co-authored-by: Katie Mazaitis <[email protected]>

Author: nmdefries

docs/api/covidcast-signals/dsew-cpr.md

@@ -44,6 +44,19 @@ Nation-level estimates may be inaccurate since aggregations are done using state
 
 Because DSEW does not provide updates on weekends, estimates are not available for all dates.
 
+### Differences with HHS reports
+
+An analysis comparing the 
+[CPR labeled January 5, 2022](https://healthdata.gov/api/views/gqxm-d9w9/files/14ee1150-edf1-4b54-b225-500c8954e6a8?download=true&filename=Community%20Profile%20Report%2020220105.xlsx) 
+(newest file as of January 6, 2022) with the HHS 
+[COVID-19 Reported Patient Impact and Hospital Capacity by State Timeseries](https://healthdata.gov/Hospital/COVID-19-Reported-Patient-Impact-and-Hospital-Capa/g62h-syeh) 
+(downloaded January 6, 2022) suggests that the CPR report undercounts the hospital admissions published by HHS by 10-15% or more.
+
+A copy of this analysis is available in Python Notebook format. We are waiting from clarification from the data provider, but until then, exercise caution when comparing work based on the CPR with work based on HHS reports.
+
+
+
+
 ## Lag and Backfill
 
 The report is currently updated daily, excluding weekends. However, this is subject to change; DSEW previously issued updates on a twice-weekly schedule. We check for updates daily.