Evidence-Based Medicine and Handhelds 14

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Evidence-Based Medicine and Handhelds

Scott M. Strayer and Mark H. Ebell

Evidence-based medicine (EBM) is an important shift in the way we learn about and practice clinical medicine. It advocates basing patient care deci- sions on a careful survey of the best available evidence; the evidence more than the expert should determine what we do for our patients. Haven’t we always done this, you might ask? Actually, no. There are many examples of common practices based on habit or tradition that on closer examination have been shown to be ineffective or even harmful, including the following:

• Not allowing infants to sleep on their backs

• Encanide or ﬂecanide post myocardial infarction

• Antibiotics for bronchitis in otherwise healthy adults

• Patches for uncomplicated corneal abrasion

• Arthroscopic lavage and debridement for osteoarthritis

• Vitamin E and hormone replacement therapy to prevent heart disease Many of these interventions made perfect sense based on physiologic prin- ciples or studies of intermediate outcomes, or observational studies, but did not stand up to the scrutiny of well-designed randomized controlled trials. As described in Chapter 10, “information mastery,” proposed by Shaughnessy and Slawson,¹takes EBM one step further by adding a focus on making sure information is relevant to your practice and by reducing the work needed to obtain it. They recommend, and we agree, that you emphasize patient-oriented evidence that matters (POEMs) in your reading. POEMs address a question about a common or important topic in your practice, measure patient-oriented outcomes (morbidity, mortality, symptom improvement, cost, quality of life), and have the potential to change practice if valid. Shaughnessy et al. also recommend that you let others do the work of scouring the literature for POEMs, critically apprais- ing them, and summarizing them for you.

Although information mastery makes it easier to practice evidence-based medicine, it is still a bigger challenge than simply doing “the same old

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thing,” doing something to a patient because “it’s always worked for me”

or “it’s the Duke (insert your favorite school here) way to do things.” Hand- held computers can make it easier to be a medical information master using some of the software that we discuss in this chapter.

For example, how about being able to look up that vaguely remembered POEM about who should be admitted for pneumonia and who shouldn’t and using it before calling admissions? Would you ﬁnd it useful to be able to calculate a patient’s 10-year risk of a myocardial infarction using the Framingham data at the point of care, and be able to demonstrate to him the drastic reduction in risk by quitting smoking or controlling blood pres- sure? What about knowing the risk of an operative delivery in your patient who wants to be induced before her cervix is ripe? EBM software for handhelds lets you do this and much more. Best of all, we believe that EBM at the point of care is a much more effective way for physicians to keep up to date and continue learning.

Why Is the Point of Care a Better Place to Answer Questions?

Experts who study adult learning have found that dark rooms with a slide projector, cold food, and bad coffee are not where adults learn best. Big surprise! These kinds of lectures can make us aware of our learning needs and holes in our knowledge base, so they aren’t completely worthless. Plus, they can be an important source of free food and coffee. But actual learning doesn’t take place for most adults until we have a problem, and solve it. For clinicians, that usually means a clinical question that arises during the care of a patient. Answering that question is how the clinician learns, and answering it with the best available evidence is what makes that clinician an “information master”.

Of course, there are many barriers to answering questions with the best available evidence:

• Time

• Knowledge of resources

• Availability of resources, particularly evidence-based sources

• Skill at searching and using computers

• Ability to understand and/or critically appraise the search results

• Local practice culture, which may not support the process

Many of these barriers can be at least partially overcome by providing clinicians with a handheld information source for use at the point of care that quickly searches several evidence-based references at once and which provides “predigested” information that doesn’t require further critical appraisal. In the next section, we’ll discuss software for Palm and Pocket PC PDA’s that has some or even all these characteristics.

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Handheld Software for Information Masters

There are many excellent programs currently available that will help you take information mastery to the bedside. The basic types of software include medical calculators, information mastery references, database programs, programmable calculators, and Web-based content viewers. Many of these programs are presented in other chapters, but we wanted to consolidate them all here so you have ready access to an EBM list of handheld software that we use and recommend. One note of caution, however, is to always check the formulas and assumptions that are programmed into the software, and remember that the ﬁnal decision for every patient should be based on a combination of the best available evidence, your clinical expe- rience, and the patient’s unique clinical situation.

The Programs

Medcalc | Palm OS | http://netxperience.org/medcalc | free download

Why memorize formulas, when you can easily access them and use them at the point of care with this free software program for the Palm OS? In addition to many clinically useful formulas, the program includes several important calculations for practicing evidence-based medicine, including likelihood ratios; numbers needed to treat; and posttest probabilities based on either sensitivity and speciﬁcity, or likelihood ratios. This is an excellent resource to help you critically analyze the literature (Figure 14.1).

Figure 14.1. Number Needed to Treat in Medcalc. (Reprinted with permission from Mathias Schopp, MD.)

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Stat Cardiac Clearance | Palm OS | www.statcoder.com | free download

Trying to remember the various risk factors for increased surgical risk can be difficult as you perform a preoperative physical for the local surgical group. How would you like to have both the American College of Cardiology/American Heart Association guidelines and those of the American College of Physicians available at your fingertips every time you need them? This handy little program lets you choose either guideline, walks you through the criteria, and based on your answers, stratifies your patient and makes recommendations for decreasing their surgical risk (Figure 14.2).

Stat Cholesterol | Palm OS | www.statcoder.com | free download

How many time have you tried to read the new National Cholesterol Education Program’s ATP III cholesterol guidelines? Even if you’ve read them, do you really know how to apply this revised guideline at the point of care? Stat cholesterol guides you through the pertinent questions, and after entering the data on your patient, will produce your patient’s risk factors, goal LDL level, and treatment recommendations based on the guideline. Lifestyle modiﬁcations are outlined, and the program lets you know when drug therapy should be initiated (Figures 14.3, 14.4).

MedRules | Palm OS | http://pbrain.hypermart.net | free download

How would you like to have 40 of the top evidence-based rules loaded onto your handheld computer for the price of your last drug lunch? That’s right, absolutely free. This program has clinical decision rules such as the Ottawa knee and ankle rules for predicting the need of an X-ray, a Bishop’s rule 340 S.M. Strayer and M.H. Ebell

Figure 14.2. Risk factors in Cardiac Clearance. (Reprinted with permission from StatCoder.com.)

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calculator that lets you predict the outcome of labor induction, and many others that can be used at the point of care. The author updates the program regularly, and it expires periodically, prompting you to download the latest version.The program also includes the references from which the rules were derived, although it does not provide details about study design or tell us how well the rule has been validated (Figures 14.5–14.7).

Figure 14.3. Major Risk Factors in Stat Cholesterol. (Reprinted with permission from StatCoder.com.)

Figure 14.4. Treatment guidelines in Stat Cholesterol. (Reprinted with permission from StatCoder.com.)

Figure 14.5. Rules screen in

MedRules. (Reprinted with permission from Kent E. Wilyard, MD.)

Figure 14.6. Bishop Score calculator in MedRules. (Reprinted with permission from Kent E. Wilyard, MD.)

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InfoRetriever | Palm OS and Pocket PC | http://www.infopoems.com/

sample/sampledownload.cfm | see Web site for cost

This is the Cadillac of information mastery software for handheld computers. Maybe the BMW. Caveat emptor: Note that part of the reason we love this software is because one of the authors (Dr. Mark Ebell) created it! It is the only software designed explicitly with POEMs and information mastery in mind:

• It focuses on information that is relevant to primary care physicians—

common and important problems, selected using the “POEMs”

criteria

• Each item is evaluated for validity and tagged with a level of evidence, and most of the references are the highest quality evidence-based materials

• It reduces work by using a single search interface to search many references, putting diagnostic test information in a simple calculator, and incor- porating more than 140 useful clinical decision rules

Table 14.1 shows the different references included in the Pocket PC and Palm versions of InfoRetriever.

InfoRetriever is available for the Pocket PC, Palm, desktop computer, and Web browser; subscribers also get a daily e-mail InfoPOEM update.

Some sample screens from the Pocket PC version are shown in Figures 14.8 through 14.12. Tapping on the down arrow next to “Select a test” in Figure 14.12 shows a list of over 20 tests, sorted by likelihood ratio.

Figure 14.7. Ottawa knee rules in MedRules. (Reprinted with permission from Kent E. Wilyard, MD.)

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Table 14.1. References included in InfoRetriever.

Reference Comment

Clinical decision rules More than 140 useful rules as simple-to-use calculators, all evaluated for validity Cochrane Database of Systematic 1700+ abstracts from the “gold standard” for

Reviews evidence-based medicine (EBM)

InfoPOEMs synopses 2400+ brief, structured summaries of relevant research

Database of diagnostic tests and history Information on more than 2000 unique

and physical examination combinations of symptom, diagnosis, and test in a handy calculator

Drug database Basic prescribing information for more than 1200 drugs

Photo atlas More than 500 photos of common problems

Evidence-based guidelines Summaries of key guidelines and pointers to evidence-based guidelines on the Web

5 Minute Clinical Consult Comprehensive reference provides information to ﬁll the gaps in evidence

Figure 14.8. Abstract from the Cochrane Database of Systematic Reviews. (Reprinted with permission from InfoPOEM, Inc.)

Figure 14.9. POEM (patient-oriented evidence that matters) summary of a recent research article. (Reprinted with permission from InfoPOEM, Inc.)

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Figure 14.10. Clinical decision rule to assist in diagnosis of strep. (Reprinted with permission from InfoPOEM, Inc.)

Figure 14.11. Background information for the strep score. (Reprinted with permission from InfoPOEM, Inc.)

Figure 14.12. Diagnostic test information for acute myocardial infarction (MI) in patients with chest pain. (Reprinted with permission from InfoPOEM, Inc.)

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InfoRetriever is updated every 4 months, and each item is indexed using both ICD-9 codes and the level of evidence. Subscribers also get a daily e-mail update with one or two recent POEMs.

HanDBase | Palm OS and Pocket PC | http://www.handbase.com |

$24.95 HanDBase Applets | Palm OS and Pocket PC | http://www.ddhsoftware.com/gallery.html | free downloads

As described in Chapter 11, HanDBase is a nifty little database application that allows you to create simple databases or download databases created by others. The databases are known as “applets,” and are available in a gallery at the HanDBase site. Many of these databases are evidence based such as the total parenteral nutrition (TPN) formula calculator (Figure 14.13) and an APACHE II score calculator for intensive care patients (Figure 14.14). If you’re feeling brave, you could even program your own evidence-based calculators using the advice in our HanDBase programming chapter (Chapter 17).

Syncalc | Palm OS | http://www.installigent.com | $19.95

Syncalc is a robust scientiﬁc calculator program that also has the ability to be programmed by advanced end-users (see Chapter 16). The beauty of this program is that several savvy physicians have taken the work out of programming and have already completed downloadable “shortcuts” that allow you to conduct several calculations important to information mastery.

The shortcuts are available on the Synergy Solutions, Inc., Web site.

Figure 14.13. TPN (total parenteral nutrition) calculator for HanDBase. (Reprinted with permission from DDH Software.)

Figure 14.14. APACHE II calculator for HanDBase.

(Reprinted with permission from DDH Software.)

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DiagnosisPro | Pocket PC | http://www.medicalamazon.com/

diagforpocpc.html | $249.95

This program provides an extensive database of differential diagnoses. You select a combination of symptoms, and the program’s expert system sug- gests a prioritized differential diagnosis. This program takes up quite a bit of room on your Pocket PC (17 MB with version 5.0), so make sure you have plenty of free memory.

Putting Web-Based Content in Your Hand

Another great way to master information using your handheld computer is to take Web pages and even entire websites with you using programs like iSilo or AvantGo. Perhaps you found a new guideline you would like to carry around with you, or you may want to put the current issue of American Family Physician in your hand. The Cochrane Web site (www.cochrane.org) has a great index to Cochrane abstracts that is perfect for either iSilo or AvantGo. We show you exactly how to use these two programs in Chapter 10.

Although more advanced users might urge you to wait until you can do this wirelessly from wherever you are located, there are limitations to this approach, including current wireless coverage, cost, and slow speed of wide- area wireless networks (taking up to a minute to load many Web pages).

Local-area wireless networks are another option, but once again, you are constrained by availability, cost, security, and inconvenience. AvantGo and iSilo let you take Web content with you right now, wherever you go (so long as you remember your handheld computer!). As we already mentioned, they both work on Palm OS and Pocket PC handhelds as well.

You can use iSilo or AvantGo to convert Cochrane abstracts (Figures 14.15, 14.16), Journal of Family Practice POEMs (Figure 14.17), and guide- lines such as the National Cholesterol Education Program’s ATP III cholesterol guidelines. Almost any evidence-based Web site is fair game, and once it is on your handheld it becomes usable at the point of care.

Summary

For physicians who want to be medical information masters, a handheld computer is as vital as a stethoscope, and perhaps more so. Great software for EBM is available for both Palm and Pocket PC platforms; perhaps the most useful are the clinical decision rules and calculators that help turn an esoteric research paper into an eminently useful decision support tool for use at the point of care.

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We have surveyed the current EBM software, but more is being devel- oped all the time. As you evaluate new software that claims to be “evidence based,” ask yourself these questions:

• Do the authors have clear, reasonable criteria for determining the rele- vance of the information?

• Do the authors explicitly evaluate the validity of the information?

• Do the authors tell you the level of associated evidence or strength of recommendation for every piece of information?

Figure 14.15. Cochrane abstracts Using iSilo. (Reprinted with permission from iSilo.)

Figure 14.16. Detail of Cochrane acute respiratory infections group abstracts using iSilo. (Reprinted with permission from iSilo.)

Figure 14.17. Journal of Family Practice POEMs Index using iSilo. (Reprinted with permission from iSilo.)

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• Do the authors go out of their way to reduce work for you by doing calculations in the background, or is it just “shovelware” with lots of text shoveled on a handheld?

• How often is the information updated?

If the answer to one or more of these questions is “No,” then consider look- ing further before spending your money.

Reference

1. Slawson DC, Shaughnessy AF, Bennett JH. Becoming a medical information master: feeling good about not knowing everything. J Fam Pract 1994;38:505–513.