The idea of assessing needs both in individuals and in populations is popul
ar in health and social care, but has serious conceptual shortcomings. The
concept of needs does not distinguish between the identification of a probl
em and its solution. It inhibits a consideration of the probabilities as to
how effective various interventions may be in any given case - nor does it
reflect the iterative process that is the reality of most health and socia
l care. It does not specify goals and oversimplifies evaluation of outcome
because it does not take into account different degrees of change. In asses
sing population needs, there is the special risk of equating service use wi
th service need, thereby entrenching the status quo. Instead of assessing n
eeds, it is proposed that we identify problems, specify goals and choose in
terventions on the basis of probabilities of effectiveness. The outcome of
any given intervention can be repeatedly reviewed with respect to its goals
, and priorities may be reset accordingly. (C) 1999 Elsevier, Paris.