Last spring, a friend of mine had an unfortunate injury, and I rushed her to a hospital emergency room. The ER physician asked what medications she was taking, and she mentioned one with which he was unfamiliar. He whipped out his personal digital assistant (PDA) and scribbled in the name as she spelled it. He promptly concluded that the medication was not a factor and would not affect her treatment.

Although this may soon be unremarkable, it was an amazing sight. The physician did not have to walk to the nurse’s station just to look up a prescription, nor did he have to break his train of thought to get the answer before moving on to the next question. The PDA allowed him to spend more time thinking about the situation at hand.

To many, PDAs may seem like the latest gadget or status symbol, and in many ways they are. In medicine, however, PDAs are increasingly used as reference materials, technical calculators, and diagnosis aids, to track patients and billing information, and to write prescriptions. PDAs may cause a larger paradigm shift in medicine than the introduction of computers.

What are PDAs?
Before we explore how PDAs affect health care, we need to understand what they are. “PDA” is a general term for any highly portable computing device, and several terms such as palmtop and handheld are used interchangeably with PDA. PDAs can be connected to a desktop computer to exchange information (such as calendar appointments and telephone numbers) and to install new programs.

There are numerous types of PDAs; however, most devices use one of the two most common PDA operating systems, the Palm OS or the Pocket PC. PDAs made to run one operating system cannot run the other, which makes choosing an operating system more important than choosing a particular PDA model.

About 70% of PDAs worldwide use the Palm OS operating system. More PDA software is available for the Palm OS than the Pocket PC, illustrating the greater use of Palm OS-driven PDAs. However, new, more demanding applications are being developed for the Pocket PC operating system, which makes choosing between the two operating systems difficult. Numerous differences must be considered when deciding between a Palm OS and a Pocket PC PDA. A description of these differences could fill an entire article. For more information, see the following link to an April 2001 article in PCWorld: (www.pcworld.com/features/article/0,aid,41466,pg,1,00.asp).

Health care
While people in many different industries have begun using PDAs, there has been extensive growth in the number of physicians using the devices. A recent survey indicated that 26% of physicians now use PDAs, up from 15% in 1999. This growth is significant because physicians are typically reluctant to use new technologies outside the operating room. Physicians in some fields are adopting PDAs more quickly than in others. Recent medical school graduates are probably the largest user population of PDAs in health care. Numerous medical schools have been the earliest adopters of the technology, and medical students have developed many PDA programs.

Many established doctors see the cost of PDAs, in terms of money and learning time, as a barrier to adopting them. This may be changing. In January 2001, General Motors agreed to buy 5000 doctors PDAs in the hope of reducing the number of prescription errors (and the costs associated with them) for GM’s workers. Programs like this, which are aimed at reducing health care costs, may be able to provide the money and training needed to convince more doctors to use PDAs.

Why PDAs?
Why are physicians using PDAs? The answer has to do with the problems that health care providers must solve. First, physicians need to have information about drugs and diseases at their fingertips. Second, clinicians of all types rarely work out of one room, and laptops are too bulky to carry from place to place every 15 minutes. Third, physicians must handle extensive paperwork. Information comes at them from all angles—medical histories from patients, drug information from books, and laboratory reports and X-rays from outside organizations. Physicians also must generate bills for patients and insurers, as well as write or call in prescriptions.

All of these needs are reflected in the programs for physicians that have been developed for the Palm OS and Pocket PC operating systems. Programs supply information to clinicians, help them assess patients, and assist them with billing and prescribing. In fact, several hospitals are experimenting with using wireless information systems to give doctors access to a patient’s medical records upon entering the room, but this is not yet widely used.

Supplying information
Putting information on portable electronic devices is not a new concept. I have an electronic English dictionary on my desk from around 1990. PDA reference materials are an extension of this trend. The physician who treated my friend most likely used ePocrates Rx (www.epocrates.com) or Physician’s Desk Reference (www.franklin.com) for the Palm OS. Many people, even those who are not familiar with health care, have seen the paper version of the Physician’s Desk Reference, a phone-book-sized directory of drugs. Not only are PDAs far easier to carry than a large reference book, but they are also easier to use because of their searching functions and other capabilities. Another benefit of PDA reference materials is that they are easily and quickly updated, because PDAs can connect to computers that download updates via the Internet.

Commercial programs such as ePocrates Rx and Physician’s Desk Reference are impressive; however, the phenomenon that may contribute most to the success of the PDA in health care is that physicians and organizations are assembling their own reference material in PDA formats. Many doctors have formed small companies to produce such resources, while others have turned their own reference books into electronic guidebooks for use on PDAs.

Carl Weber (http://cgwebermd.tripod.com/Clinical-med), a practicing physician in Washington state, has turned his 23-chapter book, The Clinical Medicine Consult, into reference guides for the Palm OS. The book, and corresponding chapters available separately for the PDA, describes how to assess and diagnose a patient. “This is a part-time endeavor,” Weber explains. “I wouldn’t give up the practice of medicine.” His foray into electronic publishing for PDAs has produced mixed results; his PDA documents are widely used, but he has not made much money from them. Says Weber, “I think the main problem [for my software] is that I do not currently have any security to prevent sharing of the text, and I suspect that many students and physicians share it after only buying a single copy.”

Clinical determination
Producing reference materials in electronic form may be only the first step in a PDA revolution. Developing programs to help collect or analyze information is the logical second step. Many programs have been developed for PDAs that prompt physicians for information from patients and keep track of that information to help with diagnosis. In other words, these programs function as automated cheat sheets.

Many of these diagnostic programs are commercial software, such as PediSuite for the Palm OS from Medical Wizards (www.medicalwizards.com), which calculates children’s dosages of antibiotics and intravenous drugs. Many other programs are produced by doctors and medical organizations. One of the most comprehensive calculators, MedMath for the Palm OS (www.stanford.edu/~pmcheng/medmath), was developed by Phillip Cheng, M.D., during his residency at the Hospital of the University of Pennsylvania. MedMath has inspired the development of new programs such as MedCalc for the Palm OS (http://medcalc.med-ia.net), developed by Mathias Tschopp, M.D., which provides additional calculations.

Billing and Rx
Although PDA reference and guide applications enjoy widespread use and continued development, applications for billing, tracking patients, and writing prescriptions have not followed quickly. Companies such as Allscripts (www.allscripts.com, software for the Pocket PC) and iScribe (www.iscribe.com, software for the Palm OS and Pocket PC) produce software that allows medical practices to write prescriptions on PDAs, which are then transferred to pharmacies. The methods used in these programs are different, but the desired results are similar: fewer errors, which saves money and possibly lives. Other products—such as PatientKeeper (www.patientkeeper.com)—keep patient records as electronic files, allowing doctors to take notes on their PDAs as they visit patients.

However, significant obstacles face billing, prescription, and patient tracking programs on the road to widespread adoption. The wireless technologies that these types of programs depend on have historically lacked security. Perhaps the ultimate fear preventing adoption of patient tracking is the possibility of catastrophic failure. If a patient had only an electronic chart and the computer system crashed, doctors would be left scratching their heads.

The usefulness of PDAs is demonstrated by the amount of development by companies and the end users, the doctors. The future holds many possibilities for PDA use, but the controversial aspects of the technology must be addressed, including concerns about security, the involvement of pharmaceutical companies in providing content, and the trustworthiness of the information used.

Michael J. Felton is an assistant editor of Modern Drug Discovery. Send your comments or questions about this article to mdd@acs.org.