The extra work with handwritten data that needs to be digitally available by manual double data entry is unnecessary with digital pen and paper as a digital "scanned" copy is available in seconds after data transfer. As a next step this data can be transformed to key stroke ditto by using Intelligent Character Recognition (ICR).

Investigators often find using a key board and looking at a screen disruptive when meeting a subject in order to fill in the CRF (Case Report Form). A common way of solving this is by taking notes by hand and later re-enter them manually or even having someone else doing this. By using digital pen and paper the traditional way of filling in the CRF can continue whilst the Sponsor and/or CRO (Contract Research Organization) get immediate access to to the data.

Yes, by letting patients report their progress with Digital Pen and Paper and a cell phone PROs (Patient Reported Outcomes) are available to investigators in seconds.

Speed and accuracy are most important. Faster access to data and much less errors than when re-entering information via key board. 

Yes the use of DP&P has been audited and approved by e.g. the US FDA.

According to the US FDA either the original paper CRF or it's digital version can be chosen but it has to be well defined.

In order to make it as easy to handle as traditional pen and paper there are some work to be done behind the scene. Captured data are to be tranformed/interpredeted into key stroke ditto and accepted before entering back end systems. The amount of work for a system integrator to do this and the size of the system will affect the cost but, in general, it is considered being a price worthy technology delivering more accurate data faster.