Thursday, March 02, 2023

 

French SARS-Cov-2 Hospital Stats for February 2023




In mid-February 2023, Sante Publique France announced a data quality problem in the hospital admissions statistics they receive.  They were not very specific in saying what the problem was, but their promise that "from February 8, 2023 on the admissions data are posted to the correct date" suggests the problem was with dates. Because I also track "cumulative number released to go home" (and "cumulative number of deaths") I think there was another, possibly related problem.


The Cumulative Releases to go Home

As these two partial screen captures show, there was a big decline in the number of patients who had gone home



Normally, a cumulative count of this sort is non-decreasing unless it is to remove prior entries which should not have been included. On February 3, 846 970 patients had gone home; on February 6, only 844 630 had: over 2 000 fewer!  By February 8, the count was back up to 848 428; the pace of daily increase has been more normal since.

One reason this statistic matters to me is to compute admissions by difference, rather than rely on declared admissions.  In principle, today's patients are yesterday's patients, less those released or deceased, plus those admitted today.  This is often the same number as the declared admissions for the day, but there are occasional differences.

Daily Declared Covid-19 Patient Admissions

There was also an anomalously large number (3,419) of declared admissions on February 8, 2023, coinciding with the large number of discharged. February 8, 2023, is the date after which, according to the warning message (at top of this post), data are posted to the correct date.




How This Impacts Tracking

First, it is important to realize that there are many fewer admissions (and discharges) on week-ends and holidays.  That is why it is common to use 7-day moving totals for tracking, to have a smoother trace. A big outlier (or error) thus messes up the trace for a week.  Two, one on Saturday offset by another the following Wednesday, create confusion for over ten days, until Thursday of the following week. That is what is reflected in orange trace in the graph below. The gap between the blue trace and the orange trace indicates growing number of patients (blue above orange) or reducing number of patients (orange above blue). The number of patients declined from about 25,000 in the last week of December to only 13,000 in the first week of February, and remains at that level.


Another observation is that the green trace, the number of positive test results scaled to match the level of hospital admissions (1 in 50) and did so until early December, is now far lower.  That suggests that far fewer cases not leading to hospitalisation are being detected. That is entirely likely, since first the labs doing the testing under-reported due to a commercial conflict with the government, then contact tracing and testing ended (1 February).

Geographic Diversity

The ups and downs discussed above were also apparent in the data at department level.  I track ten departments around the country, chosen for personal reasons I won't explain. For clarity, I've excluded the data from the perturbed days, whence the broad gap. Nowhere is there a new wave growing, but there is clearly on-going activity everywhere to varying degrees.




Tags: : France, Covid-19, 2023, Hospitals


# posted by Maurice Lanselle @ 2:10 PM 0 comments

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