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What's the spontaneous recovery rate for SAM?

This question was posted the Prevention and treatment of severe acute malnutrition forum area and has 11 replies. You can also reply via email – be sure to leave the subject unchanged.

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Victoria Sibson

independent nutritionist

Normal user

18 Sep 2010, 10:34

If there are 20 million SAM children globally and 1 million die of SAM each year, this makes it seem that many SAM children recover without treatment (given that we know global coverage of treatment to be extremely low). What do we know about the spontaneous recovery rate for SAM children?

Mark Myatt

Consultant Epideomiologist

Frequent user

18 Sep 2010, 17:33

I'll have a go at this ...

First ... it all depends on how you define SAM. Spontaneous recovery rates for SAM defined by low MUAC will be different than for low W/H. They will depend upon the case-defining thresholds used. If using W/H, they will also depend upon location, ethnicity, and food-economy zone (amongst other factors).

There is plenty of data on mortality amongst untreated children from the classic cohort studies of about 30 years ago. We can think of mortality as the opposite of recovery. It's not exactly that because it is possible to not recover and not die but it is probably safe to make the simplifying assumption that a SAM child either recovers or dies.

I just did a very quick review of some of the original reports and found a mortality rate for children with a MUAC of 110 mm to be between 100 and 250 deaths per thousand per year. Turn this about and you get 75% - 90% spontaneous recovery. As MUAC gets lower the mortality increases. At 100 mm the range was 300 to 600 deaths per thousand per year. Turn this about and you get 40% - 70% recovery.

Looking at these figures ... the 20:1 you quote seems to be wrong. The SAM definition used for this is probably using W/H which is not so strongly associated with mortality as MUAC.

This is just a quick answer. The point I am trying to make is that you can use the mortality estimates from the classic cohorts to answer this question. The problem that you may find is that it was common to define "severe PEM" as < 80% W/H ... this is close to what we now call GAM. To get answers that fit with current case-deifntions would probably require data to be re-analysed. Some of the data may be available for re-analysis.

I hope this helps.

Tamsin Walters

en-net moderator

Forum moderator

4 Oct 2010, 13:28

From Victoria Sibson:

Thanks Mark. That is helpful. I am surprised that spontaneous recovery for children with low MUAC is so high. I will try to find time to read some of the old literature

Best wishes

Vicky

Mark Myatt

Consultant Epideomiologist

Frequent user

4 Oct 2010, 14:19

As always, happy to help.

Severine

Normal user

8 Oct 2015, 10:34

Hi Mark,
Would you mind sharing the articles for the cohort you mentioned?
Many thanks in advance!
Severine

Mark Myatt

Consultant Epideomiologist

Frequent user

8 Oct 2015, 11:07

Severine,

I have the references to the cohort studies as paper reprints in a library box. They are all references in my FNB review and the (IMO) excellent Pelletier (1994) review which concentrates on mortality and anthropometry. I have put this in a ZIP archive. I guess you have good library access and will be able to get PDFs of the key documents (if you can then please send me copies).

It would be good if we could get hold of some of this data and reanalyse with current case-defintions and over more useful classes.

Severine

Normal user

8 Oct 2015, 12:51

Thanks a lot Mark!
I will keep you posted on the articles I'll manage to get from the library.
Agreed, that would be very interesting.
Best wishes,
Sev

Mark Myatt

Consultant Epideomiologist

Frequent user

8 Oct 2015, 15:25

Happy to help.

I would be happy to be part of a team looking that this data (if we can get it).

Severine Frison

LSHTM

Normal user

27 Oct 2015, 12:25

I have sent articles to Mark and Tamsin.
Please feel free to contact them or me to get a copy.

Mark Myatt

Consultant Epideomiologist

Frequent user

27 Oct 2015, 19:13

Let us thank Severine.

I have put the bundle of articles in this ZIP archive.

Severine also found this online FNB article which is also useful.

Kemal J Tunne

Mr

Normal user

28 Oct 2015, 06:50

Thanks Mark

Mark Myatt

Consultant Epideomiologist

Frequent user

28 Oct 2015, 18:36

Here is another relevant / related article. Thanks again to Severine.

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