Most people haven’t heard of whole blood viscosity yet because measurement and reporting methods for whole blood viscosity were not standardized for many decades.
There are over 10,000 scientific papers published on blood viscosity, and blood viscosity has been shown to predict cardiovascular events like heart attacks and strokes. However most of this prior research was performed using single-point rotating viscometers which meant that researchers picked their own shear rate for testing and reporting blood viscosity. Often viscosity was tested and reported at different shear rates from one study to the next.
Even though clinical research demonstrated the importance of whole blood viscosity, comparison of data between studies was difficult because of the lack of standardization. Without uniformly established practices on selection of shear rates for blood viscosity tests, this diagnostic test is still not widely used.
Today, the newest capillary-type viscometers are able to scan the entire viscosity curve, making standardization of whole blood viscosity measurement more feasible.