Can anyone give me some references/sensible suggestions
please?
One of the doctors in the transplant unit here has
quoted an infection rate of 0%, that's 0 out of 63
patients treated since 1996. A new procedure
was adopted in 1996 that should have kept the risk
of infection as low as it was before.
Historical data
(i) in the same unit prior to 1996
and
(ii) pooled data from other centres where
the procedure has not been adopted
both suggest that the infection rate was 1%
The doctor has just been asked by a referee to say
how many patients would be needed to show 'equivalence'
to the old method.
The 95% CI for the 0/63 patients (0% to 5.7%) means that
an infection rate higher than 1% higher cannot be
discounted.
The tables I have for equivalence are for 2 concurrent
groups; here one group is 'fixed'. Furthermore, the
percentages are small, so normal theory suspect.
Thanks for any help
----------------------
Linda Hunt
e-mail: [log in to unmask]
|