To illustrate both the strengths and weaknesses of the DCT 2004, psychiatry from the clinical sciences; pharmacy for the associated health professions and pharmacology from the basic sciences; and nursing theory are used.
In terms of psychiatry, it is clear that most core titles are represented. These include (but are certainly not limited to):
American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders: Text Revision, 4th Edition, 2000;
Davis's Neuropsychopharmacology: The Fifth Generation of Progress: An Official Publication of the American College of Neuropsychopharmacology, 5th Edition, 2002;
Janicak's Principles and Practice of Psychopharmacotherapy, 3rd Edition, 2001;
Sadock, Kaplan and Sadock's Comprehensive Textbook of Psychiatry – 2 Volume Set, 7th Edition, 2000
Schatzberg's Manual of Clinical Psychopharmacology, 4th Edition, 2003, and The American Psychiatric Publishing Textbook of Psychopharmacology, 3rd Edition, 2004;
Stahl's Essential Psychopharmacology: Neuroscientific Basis and Practical Applications, 2nd Edition, 2000; and
Yudofsky's The American Psychiatric Publishing Textbook of Neuropsychiatry and Clinical Neurosciences, 4th Edition, 2002.
In terms of pharmacy from the associated health sciences and pharmacology from the basic sciences, core titles listed include:
ASHP's AHFS Drug Handbook, 2nd Edition, 2003;
Allen's Ansel's pharmaceutical dosage forms and drug delivery systems, 8th ed., 2005;
Avery's drug treatment : principles and practice of clinical pharmacology and therapeutics, 3rd ed., 1987;
Cooper, The Biochemical Basis of Neuropharmacology, 8th Edition, 2003;
DiPiro's Pharmacotherapy: A Pathophysiologic Approach, 5th Edition, 2002; Evans's Trease and Evans pharmacognosy, 15th ed., 2002.
Gahart's 2005 Intravenous Medications: A Handbook for Nurses and Allied Health Professionals, 2005;
Hardman's Goodman & Gilman's the pharmacological basis of therapeutics, 10th ed., 2001;
Katzung's Basic and Clinical Pharmacology, 9th Edition, 2004
Gennaro's Remington's pharmaceutical sciences, 20th ed.;
Shargel's Applied biopharmaceutics & pharmacokinetics, 2005; and
Tietze's Clinical Skills for Pharmacists: A Patient-Focused Approach, 2nd ed., 2004.
It is clear that some fundamental texts are missing from the pharmacy/pharmacology lists. For example, Block, Wilson and Gisvold's Textbook of Organic Medicinal and Pharmaceutical Chemistry, 11th Edition, 2004; Goldfrank's toxicologic emergencies, 7th ed., 2002; and Koda-Kimble's Applied therapeutics : the clinical use of drugs, 8th ed. 2005.
With regard to nursing theory, many core titles are listed:
Anderson's Community as Partner: Theory and Practice in Nursing, 4th Edition, 2004;
Andrews's Transcultural Concepts in Nursing Care, 3rd Edition, 1999;
Cherry's Contemporary Nursing: Issues, Trends and Management, 2nd Edition, 2002;
Chinn's Integrated Knowledge Development in Nursing, 6th Edition, 2004;
Chitty's Professional Nursing: Concepts and Challenges, 4th edition, 2004;
Fawcett's Relationship of Theory and Research, 3rd edition, 1999;
Kim's Nursing Theories: Conceptual and Philosophical Foundations, 1999;
Orem's Nursing: Concepts of Practice, 6th Edition, 2001; and
Tomey's Nursing Theorists and Their Work, 5th Edition, 2002.
Missing, however, are: Fawcett's Contemporary nursing knowledge :analysis and evaluation of nursing models and theories, 2005; and some version of Nightingale's Notes on Nursing.
Thus, the strengths and weaknesses of Doody's DCT 2004 are illustrated by an analysis of the selection and rating of items in the psychiatry, pharmacology, and pharmacy sections. In the three disciplines discussed above, the DCT 2004 is more or less complete, but the rating system has too little variation (1–3) to measure meaningful differences between items. For instance, what is the true difference between mean scores of 2.5 and 2.6? or between 2.9 and 3.0? This overly restrictive range results in a system as necessarily idiosyncratic as the Brandon-Hill lists it de facto replaces. Take, for instance, the ratings of such foundational texts as the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders or Sadock, Kaplan and Sadock's Comprehensive Textbook of Psychiatry: the former is rated 3.0 and the latter 2.9. It is hard to understand how these classics are not rated the same. Not to put to fine a point on it, but if 3.0 is the highest rating of the most important psychiatric texts (the two Essential Core texts are each given a 3.0), while the mean score for Key Core titles is about 2.75, then is this mean difference between "Essential" and "Key" a distinction without a difference?
Restriction of range problem could result in spurious relationships or the attenuation of significant relationships; that is, a scale with restricted range is simply less sensitive to meaningful differences [3
]. For example, when the titles are distributed by score, we see that 189 titles are scored at 2.9, 158 at 2.8, 206 at 2.7, and 183 and 2.6. It's difficult, if not impossible, to decipher how these numbers are representing quality differences. As with many poorly explained phenomena modeled as bell curves, most items fall into the upper middle quartile.
Moreover, the owners and designers of DCT 2004 have a different interpretation of "objectivity" than what it commonly refers to, at least in terms of scale construction. For example, as mentioned earlier in the review, they state that "Relying upon scoring by multiple individuals to provide objectivity is a time-tested approach." In terms of psychometric test construction, this refers to reliability not to objectivity. Again from earlier in the review, "Use of the same five scoring tools and criteria for each title and selector – and averaging the scores across multiple selectors – yields a more objective measure than simply asking 'is this a core title."' This is typically a method to establish a scale's construct validity, not its objectivity. In fact, I think it's safe to say that objectivity is not considered a scale property.
Price seems to have little or no association with rating. The average cost of an Essential Core title is $114.56 and $119.78 for a Key Core title. The selection of key texts seems to be adequate, at least for the four disciplines discussed in this review. For nursing, Doody's DCT 2004 is certainly not as comprehensive as the Brandon-Hill in Nursing (for example, the 2002 edition of the Print Nursing Books and Journals 2002 contains 370 nursing books), but given its far more complex selection and elaborate rating systems, it may strive for comprehensiveness, but achieve selectivity. Perhaps, a way to resolve this seeming paradox is to acknowledge that while the DCT 2004 is inclusively comprehensive by covering most of the health sciences, it is more selective in terms of what comprises any given discipline.