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PDAs in clinical practice: applications and trends


Matthew Silva
Clinical Pharmacist
Family Health Centre
Assistant Professor of Pharmacy Practice
Department of Pharmacy Practice
College of Pharmacy
Worcester, MA
E:[email protected]

Personal digital assistants (PDAs) have rapidly moved into physician, pharmacist and student pockets as important clinical and educational tools. Implementing PDAs into clinical practice can enhance quality of pharmacist-delivered input at the point of service. This article will outline major concepts behind PDA hardware, operating systems and the implementation of clinical tools.

PDA hardware
The proliferation of desktop personal computers (PCs) has created a culture more comfortable with and capable of using computing solutions to maximise productivity. PDAs allow medical professionals to transfer ample computing power into a miniature form. PDA hardware designers have circumvented bulky, power-hungry peripherals by using novel technologies to integrate screen, input device, storage media, power supply and, in newer devices, wireless communication hardware, into an ultraportable device.

The central processing unit (CPU) is the core of each PDA. The microprocessors designed for PDAs run at lower processing speeds to maximise energy efficiency. PDA microprocessors are not designed to achieve the same performance as desktop PCs since they are not intended as a desktop replacement, but rather as a mobile computing solution. PDA software operating environments are more efficient, less complicated and require fewer operations per second to execute applications and deliver user productivity when compared with desktop operating environments.

Flat-panel output displays in PDAs use varying technology to display a viewing area of up to 480 x 320 pixels with more than 65,000 colours while replacing the keyboard as an input device. Colour screens will be a standard feature on 90% of all PDAs sold during mid-2004.(1) Although learning to use the handwriting recognition system can be frustrating for new users, integrating input technology into the screen area has been a major selling feature of PDAs. Thumb profile keyboard peripherals (built in as a standard feature on newer Sony and Palm branded devices) offer rapid input for users recalcitrant to handwriting recognition technology.

Energy-efficient random access memory (RAM) chips used for data storage and as memory for operating system (OS) and processing functions now replace PDA disk drives. Media expansion slots allow users to increase their mobile storage capacity 2–64-fold, allowing growth of their mobile clinical repository.

Expansion slots facilitate the addition of wireless peripherals (digital cameras, wireless 802.11b networking, Bluetooth, GPS), allowing image capture, photodocumentation, wireless network access and device connections, and global positioning. Expansion slots, initially considered high-end options for enthusiasts and technology professionals, are now standard features in new models.

The integration of this technology results in versatile, handheld computing platforms capable of a wide variety of clinical tasks and readily expandable for future applications and data storage.

PDA operating systems
The majority of devices purchased operate using Palm OS or Pocket PC. Palm OS was developed by Palm and used in all Palm branded devices and is licensed to several manufacturers, resulting in various models using the same operating platform. The Pocket PC OS licensed by Microsoft to other manufacturers provides devices that have a feel and functionality similar to a Windows-based desktop. Pocket PC devices currently offer a more diverse selection of multimedia and internet-related functions than do Palm OS devices, but the pocket PC platforms are not as robust as true Windows-based desktop PCs. Currently, Palm OS PDAs comprise the largest share of the PDA market, boasting 22.9 million Palm branded PDAs shipped, 30.1 million Palm OS licensees, 15,000 developers and 19,000 registered applications.(2) Although Pocket PC devices have gained market share, thereby reducing Palm OS market share by 16% in 2001, current trends show worldwide growth of 15% in Palm OS branded devices.(3,4)

Drug information and reference
Patient-centred activities, provider consultations and prescribing questions create the need for immediate access to drug information at the point of service. Yet immobile networked or standalone desktop PCs granting access to current electronic medical libraries are standard in most large teaching institutions. Furthermore, smaller facilities and clinics often lack the funding, staff and infrastructure to make mobile electronic resources ubiquitous. PDAs offer the pharmacist a convenient, immediate, inexpensive drug information resource at the point of service.

Several drug information resources are available in PDA formats (AHFS, ePocrates, LexiComp, mobileMICROMEDEX, Mosby Drugs, Tarascon ePharmacopoeia) to maintain an updated clinical compendium. Each drug information database provides similar basic drug information with regard to available dosage forms, dosing per indication, mechanism of action, administration and brand/ generic drug names. The additional reference features and comprehensiveness differentiate each product. Pharmacists should download free trials of most databases to identify which reference best fits their practice. For example, pharmacists practising in an adult critical care environment may not find an extensive paediatric drug database immediately useful or worth the system resources on their PDA. One of the most comprehensive and frequently utilised drug information suites used by pharmacy practitioners in academia is designed by LexiComp (see Figure 2). Most commercial drug information databases/clinical suites are available on both Palm OS and Pocket PC platforms.


Decision support
Decision support programmes (clinical calculators, risk calculators, guidelines and protocols) augment the clinical armamentarium by facilitating dose calculations, risk assessment and appropriate drug selection at the point of service (see Figure 3). Most importantly, PDA technology can help pharmacists provide more comprehensive decision support when aided by a comprehensive array of clinical tools. The pharmacists’ clinical toolkit will vary by site and practice environment. An excellent resource to begin sampling medical PDA software is Software is available supporting both Palm OS and Pocket PC platforms. Most titles are free or relatively inexpensive to purchase. Shareware titles allow pharmacists to sample each piece of software to ensure it meets their needs before purchase.


Intervention capture and medication safety
Capture of pharmacist interventions is crucial to documenting the value of pharmacist-initiated services. Pharmacist services provide evidence-based, patient-centred decision support to the medical team. The development of customised pharmacist intervention forms has facilitated the capture of clinical interventions on rounds, during chart review, order entry and through drug information services (see Figure 4).(5) The design of intervention capture forms remains proprietary, department-specific and potentially complicated. Relational database applications have been favoured in the creation of desktop-, intranet- and web-based tracking systems, which carried into relational database development for PDA platforms. A number of vendors offer relational database software suites at varying prices. HanDBase (DDH Software) offers a fairly robust, intuitive and relatively inexpensive package for pharmacy departments seeking to create custom PDA-based intervention tracking forms. Training is required when deploying custom PDA-based forms into clinical use to ensure each user is capable of completely and correctly documenting, saving and synchronising interventions into the main server. Relational databases can be designed to be efficient and easy to use, and training sessions for a department should take approximately one hour.(5)


Physician order entry and wireless communications in clinical settings are the future of complete systems integration. A system of realtime clinical alerts sent wirelessly to PDA devices from a complete system with integrated physician order entry, labs, nursing and respiratory system interfaces is a current, key goal of distributed medical informatics. The current fundamental difficulty is execution.

Current PDAs are capable of enhancing pharmacists’ service level and institutional presence by providing extensive resources directly at the point of service. Complete integration of PDAs into the larger hospital/clinic computing infrastructure is, however, beyond the capabilities of pharmacists alone. Physicians, nurses, management and information systems must support each step to facilitate implementation and project development.


  1. Brown B, Brown M. PDAs for every budget. PC Magazine 2003 May 30;99-114.
  2. Spindler L, Bartels D. PalmSource and PalmGear form strategic alliance to advance the Palm economy., September 2003. Available at URL: 20 September 2003.
  3. Kane M. Palm’s market position  erodes. CNet, January 2001. Available at URL: September 2003.
  4. Pettey C. Gartner says Palm OS licensees accounted for 51 percent of PDA shipments and 41 percent of worldwide revenue in second quarter of 2003. Available at URL: 20 September 2003.
  5. Silva MA, Tataronis GR, Maas B. Using personal digital assistants to document pharmacist cognitive services and estimate potential reimbursement. Am J Health-Syst Pharm 2003;60:911-5.

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