Epocrates Essentials: is the expanded product an improvement?

Journal of Family Practice, Jan, 2005 by Gary N. Fox, Kaleem U. Gill, R.E. Music

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Diagnoses (Dx)

Dx employs Epocrates' scrolling pick list for 1200 diagnoses. Epocrates states Dx is "powered by Griffith's 5-Minute Clinical Consult." Viewing disease monographs in the Dx section is unlike that in the Rx section: subsection titles here are not uniform. Typical subsection titles include "Basics," "Signs/Symptoms," "Causes," "Diagnosis," "Treatment," "Medications," "Related Topics," and "Miscellaneous"; the latter includes the ICD-9-CM code.

"Notes" allows users to write annotations.

With "Preferences," users may select a default opening section, such as "Basics," "Treatment," or "Medications."

"Medications" includes hyperlinks to the Rx section. However, listed diagnostic tests do not generally hyperlink to the Lab section. For example, for diagnosis of diabetes insipidus, each "vasopressin" in "Plasma vasopressin or urinary vasopressin" links to vasopressin in the Rx (not Lab) section, despite clearly referring to laboratory tests. Similarly, glucose for diagnosis of diabetes does not link to glucose in the Lab section.

Sometimes it is difficult to find specific information because of the rigid formatting. For example, despite several attempts, we were unable to quickly determine how to manage a 13-month old with a blood lead level of 13 [micro]g/dL. Hyponatremia, paroxysmal supraventricular tachycardia, and portal and pulmonary hypertension, which we noted were absent from FirstConsult (JFP 2004; 53:466-472), are all listed in Dx. For Dx, there is an alternative view by a 10-system (eg, Cardiovascular, Endocrine) initial sort, used similarly to the "by class" selection in Rx.

Laboratory values (Lab)

The Lab section alphabetically lists major laboratory tests. Subsections include "Basics," "Reference Range," "Interpretation," "Prep/Collection," and "Cost/Billing." The latter generally includes a cost range and commonly associated ICD-9 codes.

Unfortunately, for a lot of lab tests that practicing physicians look up, the Reference Range simply provides the non-informative phrase, "ranges vary with local methods," which provides no assistance with interpretation of value. For example, with vitamin D2 (25-OH-D), another source says "The normal range varies in different laboratories but is generally accepted as 15 to 50 ng/mL." (1) However, geriatricians often recommend treating empirically for values 5-10 ng/mL above the lower limit of normal, analogous to further investigating and not simply accepting "low normal" vitamin B12 values as truly normal. Similarly, there is no discussion of measuring methylmalonic acid (MMA) for "low normal" B12 levels. In fact, MMA is not listed in the laboratory section, or in the Dx section under diagnosis of B12, although the Schilling test--largely of historic interest--is listed. Lab is likewise unhelpful in clarifying management of an elevated lead level, except to define the reference range as "<9 mcg/dL" (which, actually, would be more accurately listed as "<10 mcg/dL").

Alternative views for the Lab section include "Panels Only" and "Specimen Type" (eg, Blood, Urine). The list of panels includes only about 30, ignoring, among others, those for von Willebrand's and thrombophilia. There is some hyperlinking within the Lab section and to the Dx section for diseases listed in the "Interpretation" section.