F ZUMRAWI,* J P V A U G H A N , " J C WATERLOWt and B R KIRKWOODtt
Zumrawi F [Department of Home Science, University of Khartoum, Democratic Republic of Sudan], Vaughan JP,
Waterlow JC and Kirkwood BR. Dried skimmed milk, breast-feeding and illness episodes — a controlled trial in
young children in Khartoum Province, Sudan. International Journal of Epidemiology 1981, 10: 303—308.
In a controlled trial mothers and children attending urban maternal and child health (MCH) clinics in Khartoum
Province were given a fortnightly take home food supplement of 1 Kilogram of dried skimmed milk (DSM) or an
equivalent amount of local beans. There were approximately 3 0 0 children aged 6—26 months in each group and
each child was followed for 3 to 6 months. A comparison of the two groups showed: a) that the DSM group mothers
were more likely to continue breastfeeding; b) there was no evidence to associate DSM with an increased incidence
of episodes of diarrhoea, fever or vomiting; c) the utilisation of health institutions was very similar in the two
groups; and d) there was no significant difference in the mothers' assessment of the proportion of children with a
'poor' appetite in either group. This trial met with considerable methodological problems and the results should
therefore be interpreted cautiously. There is a great need for more and better designed trials to assess the possible
adverse effects of DSM.
In a recent review of food aid, Maxwell and
Singer3 found that about 66% was sold by recipient
countries on their domestic markets to extend food
supplies and to generate funds, 16% was used on food
for work projects, 11 % was used in supplementary
feeding programmes and 7 % was used for emergency
relief. As the production of DSM in North America
and Europe considerably exceeds current requirements, excess stocks are being accumulated. It is
likely therefore, that the use of DSM will increase
in aid schemes and for emergency food supplies. In
a recent authoritative review undertaken for UNICEF
on supplementary feeding programmes, many of
which used DSM, doubts were raised about the
evidence for any benefits of such programmes for
young children in developing countries.
We undertook this controlled trial on the distribution of DSM in mother and child health (MCH)
clinics: (a) to provide information on the possible
harmful or beneficial effects of DSM on young
children and (b) to gain information on the methodological problems associated with such studies
undertaken in developing countries. Another
publication examines the effect of DSM on child
growth.s
This trial was designed as a contribution to elucidating the current world controversy on the interrelationships of breast feeding, powdered milks and
child development.1 Strong criticisms have been
expressed on the possible harmful effects of distributing powdered milks in Third World Countries,
by discouraging breast feeding and promoting
diarrhoea! disease, malnutrition and infant deaths.
The widespread distribution of dried skimmed
milk (DSM) in aid programmes imposes on obligation on the governments, UN agencies and charitable organisations which support these programmes
to monitor whether these harmful effects are also
associated with DSM.
*
Department of Home Science, University of Khartoum, Democratic Republic of Sudan.
**
Evaluation and Planning Centre, Ross Institute,
London School of Hygiene and Tropical Medicine,
Gown Street, London, WC1, UK.
t
Department of Nutrition, London School of Hygiene
and Tropical Medicine, London, UK.
tt
Tropical Epidemiology Unit, Ross Institute, London
School of Hygiene and Tropical Medicine, London,
UK.
Reprints from- J P Vaugban
303
Downloaded from http://ije.oxfordjournals.org/ at London School of Hygiene & Tropical Medicine on January 21, 2016
Dried Skimmed Milk, Breast-Feeding
and Illness Episodes- a Controlled Trial
in Young Children in
Khartoum Province, Sudan
304
INTERNATIONAL JOURNAL OF EPIDEMIOLOGY
METHODS
feeding practices and on the mother's assessment
of her child's appetite and activity.
MCH Clinic and borne follow-up visits
After the initial visit the mother and the child
should have been seen regularly at 2 week intervals,
alternately at the MCH clinic and at home. If the
mother and child were not seen on 2 consecutive
occasions an urgent home visit was made to reduce
the non-attendance and drop-out rates. At each
fortnnightly follow-up the mother was asked if the
child had had any episodes of diarrhoea, fever or
vomiting in the previous 2 weeks and if so whether
any visits had been made to a health institution.
Final follow-up
In early July 1979 the mothers were seen at the
clinic for the last time and were asked whether
they were breast-feeding or not, and for their
assessment of their child's appetite and activity.
The child's height and weight were also recorded.
RESULTS
Sample
Mothers attending the MCH clinic for the first
time with a child aged 6—26 months were accepted
into the trial. The children's ages were taken as those
given by the mothers. We attempted to exclude
children who had clinical signs of malnutrition, a
weight for age of less than 60% Harvard standard,
or who had been unwell during the previous 2 days.
The number of children who entered the trial
was 646, of whom 626 were followed for between
3 to 6 months. There were finally 287 children
in the DSM group and 339 in the Beans group.
First clinic visit
At the first clinic visit the nutrition worker weighed
the child to the nearest 100 grams with the standard
UN1CEF infant beam scales and measured the
height in centimetres with the child lying down,
using a standard UNICEF infantometer. Other
routine clinic procedures were followed and the
clinic growth card given to the mother with advice
noted on it. Then 1 Kg of DSM or beans was given
free to each mother and an arrangement made for
a home interview in the next few days. The anthropometric results will be reported separately.
Initial borne interview
The nutrition worker visited the child's home and
administered questionnaires to the mother to
obtain information on socio-economic and demographic baseline data, household conditions, breast-
The mothers were accepted into the DSM group at
a faster rate than into the Beans group due to
some initial supervision difficulties, and so there
were more child months of follow-up in the DSM
group. However, since the Beans mothers attended
the follow-ups more regularly, the total number
of recorded follow-ups was very similar in both
groups. Each child was followed-up for between
3 and 6 months.
Less than 5% of mothers missed more than 2
of the monthly clinic follow-ups and only 2.4%
did not answer both the first and the final breastfeeding questionnaire. Only 6% of children did
not have a complete set of height and weight
measurements. The percentage of male children
in the DSM and Beans groups was 49.1% and
53.7% respectively and the age distribution of the
children in the 2 groups was very similar.
A comparison of some of the socio-economic
and- demographic variables for the 2 groups is
given in Table 1. The DSM group had a lower
educational background of parents, a lower average
family expenditure on food, and less adequate
household water supplies, toilet facilities and
general household conditions. This apparent disadvantage of the DSM group makes an interpretation
of the results of the trial more difficult.
At the start of the trial significantly more of the
DSM mothers (78.4%) were breast-feeding compared
to the Beans group (64.9%) (p<0.00i). Approximately 70% of both groups of mothers said they
Downloaded from http://ije.oxfordjournals.org/ at London School of Hygiene & Tropical Medicine on January 21, 2016
MCH Centres
The cities of Khartoum, Khartoum North and
Omdurman were selected for this trial, because
they had well-organised MCH clinics at which
there had been a regular distribution of DSM,
provided by a charitable organisation for some
time. Eight MCH clinics in urban health centres
were selected and then paired for the general
similarities of the areas they served. Two pairs were
in Omdurman and one in each of Khartoum and
Khartoum North. One clinic in each pair distributed
DSM and the other acted as a control. It was decided
that it would have been unethical to withhold all
supplements and so local beans were distributed
to the control group. A female nutrition worker
was attached to each of the MCH clinics for the
duration of the trial and 2 senior nutritional workers
separately supervised the 4 DSM and 4 Beans
clinics. One of us (FZ) was in overall supervision.
The trial was carried out between December 1978
and July 1979.
305
INFANT FEEDING TRIAL IN SUDAN
TABLE 1
A companion of some family and household characteristics of the DSM
and Beans groups.
Beans
Mother hiving had primary education or more
44.3%
60.8% xxx
Families who had had one or more children
who had died
32.0%
26.9% N.S.
Families with 4 or more live children
49.6%
45.0% N.S.
Average monthly family income
(in Sudanese pounds)
£71.2
£78.1 N.S.
Average monthly expenditure of food
£37.5
£44.8 xxx
Water tap connected in house
76.0%
85.5% xx
Flush toilet in house
Household judged .to be dirty by interviewer
1.4%
7.7% xxx
15.2%
6.6% xxx
(N.S. = not significant, xx p< 0.01 and xxx p< 0.001).
TABLE 2 The observed and expected numbers of mothers stopping breast-feeding
during the trial in the DSM and Beans groups. (Both sexes children combined together).
Number in group
DSM
Beans
212
208
Observed number stopping breastfeeding during trial
32
39
Expected number stopping
43.12
27.88
0.74
1.40
Relative stopping rate
X 1 = 8 . 5 7 , d f - 1, p< 0.005
gave fresh cows and/or goats milk to their children
each day.
Risk of mothers stopping breast-feeding
The logrank6 test was used to compare the rate of
stopping breast-feeding in the 2 groups of mothers,
taking into account the ages of each child and their
varying length of follow-up. Complete information
was available for 420 mothers who were breastfeeding at the start of the trial (DSM = 212 and
Beans = 208) and 71 of these stopped breastfeeding during the trial, 32 in the DSM and 39 in
the Beans groups (see Table 2).
The following summary for all age groups shows
the number of mothers who actually stopped
breastfeeding and the number that would have
been expected to stop if the stopping rate had
been the same in the 2 groups. The Beans group
mothers were significantly more likely to stop
breast-feeding than those given DSM (p< 0.005) or
conversely, those given DSM were more likely to
continue breast-feeding.
A possible reason that might explain this difference is that the Beans group appeared to be at a
socio-economic advantage compared to the DSM
group at the start of the trial. The analysis was
therefore repeated taking into account the influence
of the following variables: family expenditure on
food of more or less than £S40 per month, whether
the mother had had any formal education and
whether the household had a piped water supply.
The difference in the rate of stopping breastfeeding
between the DSM and Beans group was confirmed,
which suggests that this may well be a real difference
and not one due to confounding variables.
Incidence of reported attacks of diarrhoea, fever
and vomiting
The number of mothers answering the illness
episode questionnaire in each 2 week follow-up
period was found and the percentage of children
having had an episode of diarrhoea, fever or vomiting in that period was calculated.
At the start of the trial there were substantial
Downloaded from http://ije.oxfordjournals.org/ at London School of Hygiene & Tropical Medicine on January 21, 2016
DSM
306
INTERNATIONAL JOURNAL OF EPIDEMIOLOGY
Attendances at health institutions
Mothers reporting an episode of diarrhoea were
analysed for their subsequent attendances at a
dispensary, health centre, hospital, pharmacy and
traditional or private practitioner (see Table 3).
Although the total number of visits in the DSM
group was twice the Beans group, this was found to
be the case at the very start of the trial and corresponds with the higher reporting rates for illness
episodes in the DSM group. In approximately
60% of diarrhoea episodes the mother and child
attended a health centre and only 1—2% went to
dispensaries. Approximately 10% did not attend any
centre. The remaining 30% was about equally
distributed between hospitals, pharmacies, and
traditional and private practitioners. The analysis
showed that the proportions varied only slightly
for diarrhoea and fever. For vomiting, however,
the percentage of hospital visits was almost double
that for diarrhoea or fever, and pharmacies were
consulted proportionately less often.
The percentage attendances in the 2 groups
were remarkably similar although it should be
remembered that the DSM group were apparently
using the services about twice as frequently even at
the start of the trial. The fact that the percentage of
hospital attendcrs in the 2 groups remained so
similar during the trial is evidence against any
difference in the severity of the illness episodes in
the 2 groups. This is particularly pertinent for
diarrhoeas because of their association with severe
dehydration and subsequent infant mortality.
Mother's assessment of their child's appetite and
activity
The mothers were asked to assess their child's
appetite and activity as good, normal or poor at
the beginning and end of the trial. The analysis is
based only on those mothers who answered both
the initial and final questionnaires. The results for
a 'poor appetite' are shown in Table 4 for all mothers
and separately for those who were breast-feeding
throughout the trial. The results for activity were
very similar.
At the start of the trial more mothers in the
DSM group rated their child's appetite (and activity)
as poor and there appears to be an improvement
at the end of the trial in both groups. The differ-
TABLE 3 Reported visits made to bealtb institutions following episodes
of diarrhoea (visits expressed as a percentage of all visits shown in brackets).
DSM (n = 593)
Dispensary
Health centre
Beans (n = 262)
1.5
0.4
61.9
61.8
Hospital
6.9
6.1
Pharmacy
9.8
8.8
Traditional practitioner
3.2
4.2
Private practitioner
4.2
6.5
No visits
12.5
12.2
TOTAL
100.0
100.0
Downloaded from http://ije.oxfordjournals.org/ at London School of Hygiene & Tropical Medicine on January 21, 2016
differences between the DSM and Beans groups in
the frequencies of reported episodes of diarrhoea,
fever and vomiting, which may have been due to
faulty interview techniques, observer bias and/or
to the socio-economic differences between the 2
groups. This reporting difference makes the interpretation of the results more difficult.
Both the DSM and Beans groups showed a
gradual decline over the period of the trial in the
percentage of children having had diarrhoea, which
was probably due to a fall off in reporting and/or
the effect of seasonal variation. The proportional
difference between the 2 groups did not, however,
increase or decrease in any significant manner. The
analysis was repeated for children breastfed throughout the trial and again no significant differences
between the incidence of diarrhoea in the 2 groups
was found.
It was concluded that despite the overall difference between the two groups in reporting rates
there was no evidence for an association of increased reporting of diarrhoea with cither DSM or
Beans, even taking into account breastfeeding
practices. The same conclusions were reached for
episodes of fever and vomiting.
307
INFANT FEEDING TRIAL IN SUDAN
TABLE 4
By all mothers
%Poor at:
By mothers who
breast-fed throughout
n
start
finish
n
start
finish
ences that existed between the 2 groups at the
start of the trial, together with the lower response
rate of the Beans group of mothers to the questions
in the final questionnaire, makes any conclusions
difficult, but there is no good evidence of a real
difference between the 2 groups (p >0.05). However, there is a suggestion, particularly for those
mothers breast-feeding all through the trial, that
appetite may have been rated as poor more often
in the DSM group then the Beans group.
All those appetites rated as 'poor' at the start of
the trial in the Beans group (15) showed an improvement whereas only about three quarters (30 out of
36) of those in the DSM group improved, although
this was not a significant difference (p X).05).
DISCUSSION
Most studies that have attempted to evaluate DSM
in 'take home' supplementary feeding programmes
have concentrated on the beneficial effects on
nutritional status, particularly child growth. Much
less attention has been paid to the possible harmful
effects and yet such considerations arc perhaps
more important for policy decisions on whether
DSM should be used or not. In view of the current
controversies there is an urgent need for more well
controlled studies to assess these possible harmful
effects.
It must be emphasised that in this study the
mothers were given the DSM and beans to 'take
home' and we have no means of knowing what
actually happened to these food supplements.
Also DSM was compared to another food (locally
purchased beans) and not with an untreated or
'pure' control group. It was considered to be unethical to withdraw a food supplement from mothers
coming to clinics where DSM had been distributed
for several years. It was also quite clear that attendance at the clinics was strongly encouraged by such
supplements.
DSM
Beans
283
164
14.8
4.6
175
13.7
4.0
9.1
0.0
91
12.1
0.0
The results of this study must be accepted with
caution because the DSM and Beans groups were
not strictly comparable on several important background variables, and also because so much of the
information had to be collected by interviewers
using questionnaires and much of the information
was based on memory recall. Also the effects of
interviewer bias must be taken into account. The
study was explained to the nutrition field workers,
who were inevitably already aware of the 'Baby
Killer' controversy, and therefore observer and
interviewer bias against DSM may explain some of
the differences between the groups in the illness
episodes data. Also the answers given by the mothers
may well have been influenced by being interviewed by nutrition workers.
The significant difference in the rate of stopping breast-feeding appears to be a definite finding
and is the opposite way round to what might have
been expected. Either the DSM supplements were
actually encouraging mothers to continue breastfeeding and without them they would have stopped,
or the receipt of Beans actually encouraged those
mothers about to stop actually to do so. It is
difficult to know which of these 2 possibilities is
most likely without the use of simple controls.
The lack of evidence in this study to associate
DSM with an increased incidence of diarrhoea,
fever or vomiting is also contrary to what is popularly held, but it is necessary to remember how
difficult it is to detect such changes unless they
are quite large and also that their incidence was
different between the 2 groups at the very start
of the trial. The lack of evidence to associate DSM
with diarrhoea is also supported by the fact that
the utilisation of health institutions, particularly
hospitals, was so similar between the DSM and
Beans group throughout the trial.
Most evaluation studies of supplementary feeding programmes have used 'objective' measurements
Downloaded from http://ije.oxfordjournals.org/ at London School of Hygiene & Tropical Medicine on January 21, 2016
% Poor at:
Percentage of children's appetites that were rated as poor
by their mothers at the start and finish of the trial.
308
INTERNATIONAL JOURNAL OF EPIDEMIOLOGY
ACKNOWLEDGEMENTS
This study only became possible because of generous
financial support from the Overseas Development
Administration (ODA) of the United Kingdom
Government. We owe many thanks to the Sudanese
Ministry of Health, the Assistant Commissioner of
Health for Khartoum Province and Dr Mohamed
Hassan, all of whom were very helpful in loaning
support, staff and equipment.
Our special thanks go to Miss Samira Hamo of
the Ministry of Health and Miss Sana Arbab of the
Ministry of Social Affairs who supervised the
field work. Our thanks must also go to Mrs Shirley
Harrison of the Tropical Epidemiology Unit for
all her special efforts in computing and analysing
this study.
REFERENCES
World Health Organization. Statement and recommendations on infant and young child feeding. Development Dialogue 1980; l i 102-119.
Chetley A. The Baby Killer Scandal. London: War on
Want, 1979.
Maxwell SJ and Singer HW. Food Aid to Developing
Countries: A Survey. Discussion paper published
by the Institute of Development Studies, University
of Sussex, Brighton, UK, 1978.
Beaton GH and Ghassemi H. Supplementary Feeding
Programmes for Young Children in Developing
Countries. Report prepared for UNICEF and the
ACC Sub-committee on Nutrition of the United
Nations. UNICEF, New York, USA, 1979.
Vaughan JP, Zumrawi F, Waterlow JC and Kirkwood BR.
An evaluation of dried skimmed milk on children's
growth in Khartoum Province, Sudan. Nutrition
Research 1981; 1. 2 4 3 - 2 5 2 .
Peto R, Pike MC, Armitage P, Breslow NE, Cox DR,
Howard SV, Mantel N, McPherson D, Peto J and
Smith PG. Design and analysis of randomised clinical
trials requiring prolonged observation of each
patient. BrJ Cancer 1977; 35i 1-39.
(Revised version received 27May 1981)
Downloaded from http://ije.oxfordjournals.org/ at London School of Hygiene & Tropical Medicine on January 21, 2016
and very little thought has been given to measuring
how mothers (who are after all very astute observers)
and families assess their children. Although appetites appeared to improve in both the DSM
and Beans group children, there was still a worrying
proportion in the DSM group whose appetite did
rot appear to improve.
The results of this trial lead us to question
some of the assumptions now generally held about
the effects of DSM on breast-feeding and in producing diarrhoea episodes. Further trials are needed
in this highly controversial area where there is so
little substantial evidence. However, such studies
need to incorporate proper 'untreated' control
groups and to pay attention to the many methodological problems involved.