Hyperbaric Oxygen Therapy - Hyperbaric Chamber Information ...

Sensitivity analysis
Table 79 shows the results of the sensitivity analysis using the 95% CI of effectiveness
from the pooled analysis of treatment effect (pages 23 to 25) varying the costs of a
doctor in attendance during treatment, the number of HBOT sessions per patient and
the number of chambers in the facility.
Table 79 Sensitivity analysis – amputations in diabetic wounds
Sensitivity Analysis Increased Cost per amputation avoided
(major and minor)
Risk difference of 11% (reduced risk for HBOT) for major
amputation and risk difference of 25% (increased risk for HBOT)
for minor amputation (worst case scenario using limits of 95% CI)
Risk difference of 30% (reduced risk for HBOT) for major
amputation and risk difference of 8% (reduced risk for HBOT) for
minor amputation (best case scenario using limits of 95% CI)
Cost of doctor/specialist covered by cost of patient assessment
prior to a course of HBOT treatment
$22,054 – primary case
Comparison therapy dominant
(more effective – less amputations – combined major
and minor)
Cost saving
Cost saving
15 HBOT sessions per patient Cost saving
40 HBOT sessions per patient $43,087
Operating costs shared between 2 HBOT units Cost saving
Operating costs shared between 4 HBOT units Cost saving
Table 79 shows that HBOT treatment costs less than the comparison treatment
(including costs of amputation), if the staff requirements of a hyperbaric nurse,
technician and physician are shared among two or four HBOT chambers in a hyperbaric
facility, if a patient only requires 15 HBOT sessions, or if the cost of a hyperbaric
physician is limited to one Medicare specialist assessment fee per patient prior to a course
of treatment. In the worst case scenario using the limits of the 95% CI, the comparison
therapy is dominant over HBOT as the comparison therapy costs less, and the total
combined number of computations is 14 less with the comparison therapy (11 less major
amputations with HBOT, 25 more minor amputations with HBOT).
Summary
If the clinical evidence of effectiveness is reliable in suggesting an average risk difference
of at least 11% in amputations then the cost per amputation avoided with HBOT is not
likely to exceed $63,100. If rehabilitation costs are included there may be a cost saving.
However if diabetic wounds was the only indication with proven effectiveness treated
with HBOT, and other indications are used most of the time, then HBOT might have a
cost-effectiveness ratio of many times those calculated above. The percentage of cases
treated which are likely to be diabetic wounds is unknown.
Wound healing
Two of the five studies of HBOT in the effectiveness assessment of diabetic wounds
examined wound healing as an outcome of interest, although none offered an objective
definition of the phenomenon. The small number of patients (only 38 subjects) translates
to wide confidence intervals in estimates of individual and pooled treatment effects.
Hyperbaric oxygen therapy 85