"difficulty of use" is a correct and usable phrase in written English.
You can use it to refer to the difficulty in using something (an interface, a product, etc.). For example, "The complexity of the software made it difficult to get used to its functionality, and the difficulty of use caused a lot of frustration."
The participants favored Trios over iTero in terms of difficulty of use, patient comfort, and clinical usefulness.
The parameters of evaluation included difficulty of use, patient comfort, preference, and clinical usefulness.
The parameters of questionnaires included on difficulty of use, patient discomfort, awareness, preference, and clinical usefulness of intraoral scanners and comparison of two types of scanners.
However, existing limitations including model uncertainty, computation time, difficulty of use and steep learning curve.
The participants also indicated low levels of difficulty of use and high levels of satisfaction and sense of presence.
Research has identified issues preventing their mainstream adoption to be, among others, the gap between PSS supply and demand (Geertman, 2016), their difficulty of use, a need for greater understanding of PSS capabilities and a lack of awareness of their applications (Russo et al., 2017; Vonk, Geertman, & Schot, 2005).
Therefore, synthetic scaffolds represent potentially attractive alternatives to naturally derived substrates as they overcome many of the practical pitfalls associated with naturally derived substrates, including uncontrollable reproducibility, instability, poor mass transfer and difficulty-of-use.
Experts noted the obvious difficulty of using a standardized test to compare countries and cities of vastly different sizes.
What has held it back, she said, is the difficulty of using a digital camera and downloading the images to a personal computer.
Mr. Haskell, the Nightmare designer, lamented the difficulty of using anything but the most durable of materials.
