Why am I getting higher than expected readings?

Why am I getting higher than expected readings?
A. Several factors could influence the blood glucose readings.
1. Residual alcohol on fingertip will cause falsely higher readings. So make sure either alcohol is air dry or wipe dry with gauze.
2. If blood is smeared, the reading could become higher because the strip is collecting just serum, or lower if not enough blood is collected.
3. Patient’s health conditions
a. Medications
b. Time and dose of insulin were administered
c. HCT level
d. Interference factors in diet, such as vitamin C (ascorbic acid), glutathione (antioxidant), and uric acid (for GDH strips)
e. Hydration level for patients
4. Any recent food uptake will also increase the glucose readings. Therefore a fasting glucose would be recommended if need to compare to lab results.