ENGLISH OUS indications
Page 41 of 50
OTH-SEM-IFU-OUS-0359 Rev I
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False positives - no visible pressure injury/ulcer and a SEM delta of 0.6 or above
(“abnormal levels of SEM”). There were 261 anatomical sites in this category.
The bootstrap method was used to account appropriately for the within subject correlation in
the estimates of the 95% confidence intervals for sensitivity and specificity. The bootstrap
method was applied by sampling, with replacement, from the original dataset. The sampling was
done on a per subject basis such that all records for a randomly chosen subject were extracted.
One thousand datasets were generated using this method, each with the same number of
subjects as the original dataset.
Estimates of sensitivity and specificity were then calculated across datasets by taking the median
value. The confidence limits were generated from the 2.5
th
and 97.5
th
percentiles. This resulted
in the following estimates (Table 11).
