Better nutrition. Not better result

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Hi All,

Do better markers of nutrition correlate with the outcomes that are predicted in

carefully controlled trials? Maybe, the correlation is poor.

See the below excerpts from the pdf-available article.

Koretz RL.

Nutrition Society Symposium on 'End points in clinical nutrition trials' Death,

morbidity and economics are the only end points for trials.

Proc Nutr Soc. 2005 Jul;64(3):277-84.

PMID: 16048658

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\

ct & list_uids=16048658 & query_hl=30

.... results were analysed only in relation to the direction of the respective

changes in outcomes. Forty-eight comparisons (4x12) were made. The rates of

concordance were </=50% in forty-one of forty-eight comparisons; the rate was

never

>75%. A complete discordance rate of >/=25% was present in forty-three (>/=50%

in

thirteen) of the forty-eight comparisons. The discordance was usually a result

of

the nutritional outcome being better than the clinical outcome. Changes in

nutritional markers do not predict clinical outcomes. Before adopting any

surrogate

marker as an end point for a clinical trial, it has to be known that improving

it

will result in patient benefit.

.... Changes in nutritional markers do not predict clinical outcomes. ...

.... Table 2. Impact of nutrition support on clinical and nutritional outcomes

.............................................

----No. of studies----Improved by nutrition support

--------Statistically significant At least arithmetic

Outcome n %----total n % total

.............................................

Nutritional

Energy intake 34 29 85 30 88

Protein intake 19 17 89 18 95

Weight gain 61 33 54 51 84

N balance 43 39 91 43 100

Albumin 62 7 11 35 57

TSF thickness 32 8 25 20 63

MAC 16 3 19 11 69

MAMC 22 5 23 17 77

Transferrin 28 11 39 21 75

Prealbumin 23 8 35 21 91

Skin tests 12 2 17 8 67

TLC 9 0 - 6 67

Clinical

Mortality 87 1 1 36 41

Infections 62 2 3 20 32

Total comp 59 4 7 24 41

Dur'n hosp 38 1 3 21 55

..............................................

TSF, triceps skinfold; MAC, mid-arm circumference; MAMC, mid-arm muscle

circumference; TLC, total lymphocyte count; comp, complications; dur'n hosp,

duration of hospitalization.

Table 3. Rates of concordance and discordance between various clinical and

nutritional outcomes

...............................................

-------- - - Partial discordance Complete discordance

Outcome No. of trials Concordance Nutrition better* Clinical better†

Nutrition

better* Clinical better†

...............................................

Energy intake

Mortality 31 42 29 - 29 -

Infections 22 32 23 - 45 -

Total comp 20 30 20 - 50 -

Dur'n hosp 18 44 17 - 39 -

Protein intake

Mortality 18 22 33 - 39 6

Infections 13 23 23 - 54 -

Total comp 9 11 33 - 56 -

Dur'n hosp 8 50 25 - 25 -

Weight gain

Mortality 56 40 23 2 29 5

Infections 36 31 8 - 56 6

Total comp 34 41 12 3 38 6

Dur'n hosp 14 50 7 14 21 7

N balance

Mortality 36 36 42 - 22 -

Infections 30 43 17 - 40 -

Total comp 31 48 16 - 35 -

Dur'n hosp 25 56 8 - 36 -

Albumin

Mortality 56 29 18 20 25 9

Infections 37 38 16 8 32 5

Total comp 35 43 11 9 29 9

Dur'n hosp 24 50 8 4 21 17

TSF thickness

Mortality 30 27 10 20 33 10

Infections 24 13 25 4 42 17

Total comp 18 22 17 6 28 28

Dur'n hosp 8 63 - 13 13 13

MAC

Mortality 16 50 17 13 13 7

Infections 12 33 17 8 25 17

Total comp 12 42 17 17 8 17

Dur'n hosp 4 50 - 25 25

MAMC

Mortality 21 24 19 5 48 5

Infections 19 11 11 16 63 -

Total comp 10 30 10 10 50 -

Dur'n hosp 5 40 20 - 40 -

Transferrin

Mortality 26 35 19 19 23 4

Infections 17 41 12 - 41 6

Total comp 17 29 6 24 35 6

Dur'n hosp 12 25 8 - 42 25

Prealbumin

Mortality 18 33 39 6 22 -

Infections 16 38 6 - 56 -

Total comp 15 60 13 - 27 -

Dur'n hosp 9 44 - 56 -

Skin tests

Mortality 12 42 17 17 25 -

Infections 8 25 38 13 25 -

Total comp 5 60 20 20 -

Dur'n hosp 5 40 20 20 20 -

TLC

Mortality 6 33 17 33 17 -

Infections 3 67 - 33 -

Total comp 7 57 14 - 29 -

Dur'n hosp 4 75 - - 25

.........................................

Comp, complications; dur'n hosp, duration of hospitalization; TSF, triceps

skinfold;

MAC, mid-arm circumference; MAMC, mid-arm muscle circumference; TLC, total

lymphocyte count.

*The effect of the therapy was more beneficial on the nutritional outcome than

on

the clinical outcome, e.g. if the clinical outcome was ‘no different’, the

nutritional one was ‘better’ or the nutritional outcome was ‘no difference’

while

the clinical outcome was worse.

†The effect of the therapy was more beneficial on the clinical outcome than on

the

nutritional outcome, e.g. if the nutritional outcome was ‘no different’, the

clinical one was ‘better’ or the clinical outcome was ‘no difference’ while the

nutritional outcome was worse.

.... In order to assess the ability of enteral or parenteral nutrition to alter

the

clinical course of any underlying disease process in a favourable way, it must

be

shown that its use will improve mortality or morbidity (and does so at a cost

that

is affordable in a resource-constrained environment). ...

A definition is: enteral - A method of nutritient delivery where fluid is given

directly into the gastrointestinal tract.

Al Pater, PhD; email: old542000@...

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