Welch Allyn RETeval-DR Directions For Use Manual page 23

Directions for use
System information
View GTIN
The Global Trade Item Number (GTIN) is a globally unique 14-digit number used to
identify trade items, products, or services.
1. Scroll down to Settings > System > GTIN.
2. Press the joystick.
The GTIN is displayed.
Change system settings
1. Scroll down to Settings > System > Change settings.
2. Press the joystick.
Update firmware
Follow the instructions in the firmware update notice to download the firmware update.
Additional information on managing firmware updates can be found in the "Manage
firmware" section of this manual.
1. Scroll down to Settings > System > Change settings > Update firmware.
2. Press the joystick.
3. Select the firmware update you would like to use and press the joystick to select
Next.
4. Wait while the firmware updates.
The device will restart automatically when the firmware is updated.
Adjust reference interval
The score produced by the DR Assessment Protocol correlates with the presence and
severity of diabetic retinopathy and clinically significant macular edema. Patients with
more-severe levels of diabetic retinopathy will typically have higher test scores (Maa et
al. 2016).
The default reference interval for RETeval-DR is set at 7.0-19.9; this reference interval
can be adjusted to trade off sensitivity, specificity, and negative predictive values by
varying the upper point of the reference interval, as shown in the examples below.
Sensitivity, specificity, and predictive values at multiple cutoff values
Upper interval Sensitivity
17.5
18.0
19.0
19.9 (default)
21.1
Specificity
93% 52%
90% 57%
88% 67%
83% 78%
73% 84%
Predictive power of test
Positive Negative
8% 99.5%
9% 99.2%
11% 99.1%
15% 99%
17% 99%
Setup 19