This paper presents the findings from the second pilot study of the cost bl
ock method in 21 adult general intensive care units (ICUs). The aim of this
study was to explore the possible reasons for the variation in cost identi
fied in a previous pilot study of 11 ICUs. Data were collected for the six
cost blocks for the financial year 1996/97. Multivariate analysis showed th
at 93% of the variation in expenditure on disposable equipment could be exp
lained by the number of ICU beds, the number of admissions and the presence
of a high-dependency unit (HDU). Ninety-two per cent of the variation in n
ursing staff expenditure was explained by the number of ICU beds and the pr
esence of an HDU. Hospital type and the number of patient days explained 76
% of the variation in expenditure on consultant staff. Sixty-four per cent
of the variation in drug and fluid expenditure was explained by the number
of patient days.