Tablet PC and digital pen trump PDA for mobile data entry

Researchers may be ready to set aside traditional pen and paper for performing data entry in large clinical trials. Not only do investigators prefer their digital counterparts, but those devices also lead to a reduction in data entry errors.

"Currently, all data entry for clinical trials are initially completed on paper forms," said Elodia B. Cole, a researcher at the University of North Carolina, Chapel Hill.

Forms for clinical trials, in this case mammography trials, can be long and full of information. The mammography worksheets used for this study ran to 17 pages and included 119 different elements, Cole said.

For a mobile data entry device to be considered as a replacement for pen and paper methods, it had to be portable and easy to use, not take longer than entering data with a pen and paper, and provide data verification capability, she said.

Cole and colleagues compared a Tablet PC, digital pen, PDA/digitizer hybrid, and a traditional PDA in terms of speed, ease of use, accuracy, and user satisfaction. Pen and paper entry was used as a control.

Five radiologists entered information from 20 screening examinations using each of the devices.

Not surprisingly, with its intuitive advantage, the standard paper control was the fastest method of data entry, at an average time of 155.2 seconds per case. The stand-alone PDA had the slowest result, at an average of 276.6 seconds for complete entry.

However, there was no statistically significant difference between data entry times for the digital pen, pen and paper, and the Tablet PC, according to Cole.

In terms of usability, the PDA was the hardest to use, with over 70% of the cases requiring assistance.

"Users were equally satisfied with the digital pen and the Tablet PC and were more satisfied with these platforms than with the PDA and the hybrid," she said.

Because the completed pen and paper forms had to be entered manually into information systems, 27.5% of these cases had at least one data entry error, 10% had at least two errors, and 6.25% had at least three errors. With the electronic pen, 13.33% of the cases had at least one character recognition error, 3.33% of the cases at least two errors, and no cases had more than two errors.

One of the major problems with the PDA and the PDA hybrid, Cole said, was its small screen size, which required both horizontal and vertical scrolling. Additionally, navigational limitations forced users to go through the form sequentially rather than skipping around, which they could do with the Tablet PC and digital pen.

The institution plans to begin a clinical trial studying the Tablet PC and digital pen in the spring of 2005.

For more information from the online Diagnostic Imaging Archives:

Wireless PDAs may prove useful for image interpretation

Tech advances bolster use of PDAs by radiology residents