Aanesthetic Agents for Day Surgery - NIHR Health Technology ...

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Results of the paediatric economic evaluation
patterns in the data and to adjust the estimates of
the risks of PONV among the various anaesthetic
regimens. The independent variables explored were
anaesthetic regimen (categorical), age (numeric),
gender (categorical), orientation (categorical),
duration of anaesthesia (numeric), ASA grade
(categorical), previous anaesthetics (numeric)
and surgical procedure (categorical).
The analysis was performed in an exploratory
manner (informed by the findings from the
tables) rather than merely letting the analytic
routine find the best fitting, and not necessarily
most informative, model. The final model selected
(see below) turned out to be the best fitting, most
parsimonious and intuitively most appealing
among several candidate models.
Logistic regression analysis confirmed the tabular
analyses. None of the variables, other than anaesthetic
regimen, made any contribution to the fit
of the model. Thus the best estimate of the ORs is
as calculated from Table 53, which also gives the
associated 95% CIs.
Resource use data
Table 54 summarises the length of stay and the
principal cost parameters of the paediatric
TABLE 53 ORs for PONV in the paediatric study
Outcome Anaesthetic OR (95% CI)
regimen
Nausea or Sevoflurane/ 2.88 (1.29 to 6.40)
vomiting sevoflurane vs
propofol/halothane 1 (NA)
Any vomiting Sevoflurane/ 4.13 (1.14 to 14.9)
sevoflurane vs
propofol/halothane 1 (NA)
TABLE 54 Length of stay and principal cost parameters in the paediatric study
patients. Figure 18 shows the distribution of the
length of stay data. No statistically significant
differences were found between these factors for
the different anaesthetic regimens (p = 0.867).
There were four overnight stays (1.2%), two of
which were general male and two of which were
ENT male patients. There were two overnight stays
in each randomisation arm. The reasons for these
overnight stays were more extensive surgery, hypoglycaemia,
organisational reasons and bleeding.
The total costs include all costs from the NHS
perspective, including postdischarge costs (e.g.
readmission, GP visits). Variable costs exclude
staff, fixed and postdischarge costs. Sevoflurane/
sevoflurane had significantly higher total costs
(p < 0.0001) and variable costs (p = 0.0001) than
did propofol/halothane. For the distribution of
the variable costs data, see Figures 19 and 20.
Postdischarge NHS costs and parents’/guardians’
own costs were obtained from 260 respondents
who were followed up with a telephone interview
at day 7. Postdischarge costs and self-care costs
incurred by parents/guardians postdischarge are
summarised in Table 54. Postdischarge NHS costs
and patients’ own costs were minimal and did not
differ between anaesthetic regimens.
Parent/guardian preferences
and CV data
The preference and CV data were from the
parents/guardians of children in the CESA RCT.
These were obtained by telephone interview
7 days postoperatively.
Preference for induction of anaesthesia
The 260 parents/guardians of the children
included in the CESA RCT were asked for a
Parameter Propofol/halothane Sevoflurane/sevoflurane Total
(n = 159) (n = 163) (n = 322)
Mean (SD) length of stay (h) 5.2 (2.4) 5.1 (1.9) 5.1 (2.2)
Mean (SD) total cost (£) 84.0 * (21.2) 94.5 * (24.7) 89.3 (23.6)
Mean (SD) variable cost (£) 3.5 * (1.9) 12.4 * (5.9) 8.0 (6.3)
Parents’ own costs (SD) (£) 0.04 (0.26) 0.03 (0.18) 0.04 (0.22)
(n = 125) (n = 135) (n = 260)
Postdischarge NHS costs (SD) (£) 2.3 (8.3) 3.6 (12.7) 3.0 (10.8)
(n = 125) (n = 135) (n = 260)
* p = 0.0001