Long-term survival and mortality
Eight of the 12 papers reviewed identified inferior long-term survival
or higher mortality rates for those who had prolonged LOS in ITU in
comparison to ‘normal’ LOS or a control. Mahesh et al.(10) reported overall survival at one year for
prolonged ICU stay to be 89.2% vs 97.8% for the control group of LOS
of less than three days, and 81.2% vs 93.6% at three year follow-up.
Heimrath et al. (22) reported mortality rates
of 14% in the prolonged LOS group vs 4% for the control (p=0.001).
Elfstrom et al. (23) stated the mortality risk
of groups with LOS 3-7 days and 7-14 days to be 50% higher than that of
the ‘normal’ LOS. High mortality rates for those with prolonged ITU LOS
were also reflected in findings by Gaudino et al.(9) where 57 participants survived to discharge and
78.9% of them died during follow-up (over an average of six years), of
which 29 deaths were attributed to cardiac causes. However, it is
important to note that this particular study had a small sample size
(n=57) with no control population for comparison, therefore limiting
generalisability of their findings to the wider population. Hassanet al. (24) and Hein et al.(5) reported poorer long-term survival in those with
prolonged ITU stay that was more marked in the first six months to one
year post-discharge. Long-term survival was 70% in the prolonged group
vs. 90% in the control (p= < 0.001) (24)with similar results produced by Hein et al.(5) with 66% survival in the prolonged group vs. 91%
in the control (p=0.001). There was a steep decline in survival in the
first six months of follow-up, but the six-month to three-year period
was comparable (with a 7% difference in decline for the prolonged group
vs. 4% for the control) which led the authors to conclude that chances
of survival are comparable if they overcome the first six months
post-operatively (5) . Similar findings and
conclusions were made by Hassan et al. (24) who
demonstrated inferior long-term survival amongst patients with prolonged
ITU LOS, especially within the first year after discharge, stating that
the greatest burden of mortality is within the first year
post-operatively.
Conversely, Silberman et al. (25) found that a
significant number of patients went on to experience reasonable
long-term survival. Of those with LOS ranging from 1-2 days and 1-3
weeks, 90% were alive at one year follow-up. Eighty per cent of those
with a LOS of one week and 50% of those with a LOS of two weeks were
alive at five years. This was the only study to identify a proportional
relationship between ITU LOS and overall late survival. They also found
that for those with an extremely prolonged LOS in ITU (more than 30
days), the highest rate of mortality is in the first year. Manjiet al. (26) took a different approach to their
analysis by looking at ‘functional survival’ which they defined as
patients being alive and not institutionalised. They found that the
control group achieved 94.9% functional survival at one year vs. 73.9%
for prolonged ICU stay and 84.9% vs. 53.8% at five years, which was
considered a successful outcome by the authors. However, although the
majority were alive and non-institutionalised, it is not known what QoL
was like for these patients or whether they were requiring care or
support at home as no assessment of QoL of functional status was made.