A one-year birth cohort was studied in Jimma town, South West Ethiopia
, in 1992-93. We report here on the design and on the methods used in
the study and describe the principal health outcomes. Infants were vis
ited bimonthly until their first birthday. Background data on the phys
ical, cultural and economic environment of the home were collected at
the first visit, and data on nursing and weaning, on traditional surgi
cal and other practices, and on vaccination at the first visit and at
each subsequent visit. Length, weight and mid upper arm circumference
were measured, and details of the mother's handling of illness episode
s recorded. Of 1563 children born, 86% were successfully followed to t
he end of their first year or to an earlier death. There were 141 deat
hs, indicating an infant mortality of 115/1000 (estimated probability
of surviving to 1 year 0.8851, with s.e. 0.0101). The mean length and
weight of the singleton infants at the end of their first year was - 1
.41 and - 1.52 so from the median of the NCHS/WHO reference population
. Weights throughout the first year were analysed in more detail using
a Reed model, fitted as a random coefficient regression model in ML3-
E. There were clear differences in growth across the different ethnic
groups, with the best growing group weighing on average about 1 kg mor
e at the end of the first year than the groups growing least well.