Computerized Reference Management: Searching ...

641

Computerized Literature Jud

W. Gurney1

and

Reference Robert

Management:

Searching

the

S. Wigton2

With the addition of more than 225,000 articles yearly to the medical literature, it becomes increasingly difficult for the practicing radiologist to keep abreast of medical knowledge. This problem is not limited to radiology. Over one-third of recently surveyed internists and otolaryngologists expressed dissatisfaction with their ability to keep up with new developments [1 1. Personally searching a topic through volumes of!ndex Medicus is frustrating and time consuming. Searches performed by medical librarians can be very expensive and may take several days to complete, limiting their use to the most important problems. To help in gathering pertinent medical literature, one academic Radiology Department has developed a comprehensive information service using a clinical medical librarian [2]. A similar project proved successful in a Department of Medicine [3]. However, most academic departments and private physiclans do not have the funds to support such an undertaking. The introduction of the personal computer has revolutionized access to the scientific literature, making individualized computer searches in the office or at home possible and less expensive than a medical librarian’s. With a small amount of time and effort, a radiologist can learn the techniques of computerized bibliographic retrieval. Database services, both public and private, provide access to the world’s medical literature. These services differ in ease of use, cost, and capability of extracting the desired information.

Medicus. Citations are printed in Index Medicus under one to three headings but may be listed under 20 on-line. MEDLINE citations may be located by language, geographic area, or a word that appears in the title or abstract; Index Medicus does not have this capability. References are available on-line weeks before they are printed in Index Medicus. Quick reading of an abstract often will identify articles worth pursuing, and abstracts may be withdrawn from the majority of articles accessed in MEDLINE. When using Index Medicus, the researcher must pull and scan each article. While Index Medicus is usually located only in medical libraries, computerized

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Analysis

Bibliographic

Searching Anatomy

The most important medical database is MEDLINE, the computerized counterpart oflndex Medicus. MEDLINE is one of several databases compiled by the National Library of Medicine in a database service known as MEDLARS (Medical Literature Analysis and Retrieval System). MEDLINE contains over 4 million references from more than 3200 journals, divided into back files covering 1966 to the present. The literature may be searched by hand with Index Medicus or by computer with MEDLINE, but the contrast is striking. More search terms are available on-line than through Index

lilt

Lung

and

Histology

rastricture

diseases

Fig. 1 -Bibliographic search on pulmonary processes that predominate in upper lobes of the lung. For the year 1984, 52 pages were reviewed induding 16 major MeSH headings previously loentified in theAnnotated MeSH. Over 4500 citations were scanned, 32 were noted as possibly relevant. Total search time exceeded 1 hr. the

Received November 12, 1985; accepted after revision April 9, 1986. I Department of Radiology. Medical College of Wisconsin, Milwaukee County Medical Complex, 8700 W. Wisconsin Ave., Milwaukee, requests to J. W. Gurney. 2 Section of General Internal Medicine, University of Nebraska Medical Center, 42nd and Dewey. Omaha. NB 68105. AJR

147:641-445,

September

1986

0361-803X/86/1472-0641

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MEDLINE

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together related

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searches may be performed anywhere that is equipped with a microcomputer and the appropriate modem and software. Searches on MEDLINE can be intricately constructed and tailored by author’s name, journal of publication, a word in the title, or one or a combination of 1 4,000 medical subject headings (MeSH terms) used by the National Library of Medicine in indexing and cataloging materials. A useful tool when planning a search strategy, MeSH is a thesaurus of terms used in indexing and analyzing the literature. Several books published by the National Library of Medicine arrange MeSH headings in different sequences convenient for searching. Annotated MeSH is an alphabetical list of MeSH headings, each of which provides information and history on its use, cross-references to other MeSH headings, and synonyms that may lead to preferred terms. Permuted MeSH takes each significant word that appears in every MeSH heading and lists all associated MeSH headings in which that word appears. It is useful in researching topics not covered in a single MeSH heading. A topic such as “solitary pulmonary nodule,” when examined in Permuted MeSH under “pulmonary,” cross-references to “coin lesion, pulmonary,” a related heading but one that might be missed in the alphabetical list. Related headings that may be more appropriate for searching are found in this manner. Tree Structures is a list of MeSH headings categorized by subject and arranged in hierarchial fashion from general to specific. A search may be narrowed down to a more precise MeSH heading, providing a higher

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identified

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all

the

above

criteria)

of relevant

articles

for retrieval.

To find references to a particular clinical problem, one would consult the MeSH manuals to identify pertinent headings and then review monthly and yearly volumes of Index Medicus through the desired time span for each of these headings (Fig. 1). Although there is no fee for this method, the search is tedious, especially if searching is performed over many years and volumes. For several years, Radiology has published a “Cumulative Index,” cataloging articles from many of the major radiologic journals. Fewer terms are used in coding than in MeSH headings, and they are not organized in a stratified manner. While the “Cumulative Index” is easy to use and provides a quick reference to the radiology journals, research of a topic that spans other journals requires use of Index Medicus or computerized searches of MEDLINE.

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Fig. 2.-MEDLARS’ search to find recent literature on lung diseases in upper lobes. Performed by a medical librarian, search cost $1 7 with turnaround time of 28 hr. Same search on a home microcomputer took 15 mm, cost $4.50, and was downloaded into a database manager for storage. Parenthetic statements give brief description of commands and output from MEDLARS’ search. User input is in lower-case type.

Retrieval

Until recently, only librarians and specialists with extensive training performed on-line bibliographic searching. Now, using a computer terminal, a modem, a telephone, and a password, a radiologist can have access to a wealth of information. The process of searching is simple. After connecting on-line to a database, the user conducts a dialog with the computer by typing in successive queries until the needed references are identified. The typical search requires 1 0-1 5 mm; results can then be printed or stored on magnetic tape or disk (downloaded) for later use. MEDLINE may be accessed directly through the National Library of Medicine using MEDLARS (Fig. 2). Completion of a 1-day training course, offered throughout the United States, is required before one can use the MEDLARS system. A modest investment in searching manuals is also necessary to use MEDLARS fully. The least expensive technique for on-

AJR:147,

COMPUTERIZED

September1986

TABLE

1 : Interface

Programs

for Medical

Title

GRATEFUL

LITERATURE

Literature

MEDLARS National

Management Library

System

Section

of Medicine

(301)

double-density

disk drive

Informa-

Apple ][+ with CP/M 2.2 (56K) and two floppy disk drives, or IBM PC (or compatible)

City Science Center

Philadelphia, PA 19104 (800) 523-4092 Menlo Corporation 4633 Old Ironsides, Suite Santa Clara, CA 95050 (408) 986-0200

“SeeWton

with 256K

496-6193

151 Institute for Scientific tion 3501 Market St.

University

Pro-Search’

Requirements

IBM PC (or compatible)

RAM and one double-sided

Bldg. 38A, Am. 4n421 Bethesda, MD 20894 Universal

643

Searches

Address

MED

Sci-Mate: Online Searchera

SEARCH

400

IBM PC (or compatible) RAM

with 256K

151.

bWt(6l

TABLE

2: Database

National

Library

Services

of Medicine

(NLM)

MEDLARS Management Section National Library of Medicine 8600 Rockville Pike Bethesda, (301)

MD 496-6193

Bibliographic BRKTHRU BAS After

20209

Retrieval Services (BRS) Database

Latham, NY 12110 - 2 - ASK BRS Information Services, Dialog (800) DIALOG

Inc.

Knowledge Index 3460 Hillview Avenue Palo Alto, CA 94304 334-2564

PaperChase Beth Israel Hospital 330 Brookline Avenue Boston, MA 02215 (61 7) 735-2253

AMA/GTE Medical Information Network (MINET) GTE Telenet Medical Information Network 8229 Boone Blvd. Vienna, VA 22180 (703) S

Vendors

Dark

BAS/Colleague 1200 Route 7

(800)

nects to the library’s computer, performs the search, and downloads the results. Off-line, the user assesses retrieved citations for appropriateness. GRATEFUL MED then analyzes the articles judged to be relevant and nonrelevant and suggests MeSH headings that may be useful in further search.

442-2500

Not mentned

in text. Contact GTE for further information.

line bibliographic retrieval, MEDLARS provides the capability to perform the most sophisticated of searches, tailored to individual needs. For the occasional searcher who may not be interested in learning the complexities of the MEDLARS system, the National Library of Medicine has recently offered a user-friendly software package named GRATEFUL MED (Table 1), designed to simplify the search process. The user constructs a search off-line and then connects to the on-line service by filling out a series of screen menus. The software then con-

MEDLINE may also be accessed by one of the commercial database services, such as DIALOG or Bibliographic Retrieval Services (BRS), which lease MEDLINE from the National Ubrary of Medicine. A subscription to these services (Tables 2 and 3) offers an alternative to the use of MEDLARS. These vendors, though somewhat more expensive, offer several advantages. First, they provide access to a wide number of databases. DIALOG, for example, offers more than 200, including additional medical databases such as Biosis Previews, Embase (Excerpta Medica), and Sci-Search, as well as databases covering business, basic sciences, law, and so on. A radiologic user may wish to access these other databases for topics such as physics, computer imaging, or education [4]. A second advantage of a database service is that the vendor provides searching commands and menus that are not only easier to use than those of the individual database, but are similar across all of the databases offered; once the commands for one database are learned, there should be no trouble with the others. The disadvantage of these “userfriendly” commands is the lack of flexibility in planning and performing searches. In general, reference retrieval is less comprehensive and specific than in literature searches using the direct access of MEDLINE from MEDLARS (Fig. 3). A third advantage is the expanding variety of new offerings in addition to bibliographic databases. BRS/Colleague, for example, offers several full-text journals and textbooks online. The entire contents ofjournals such as Annals of Internal Medicine can be searched through this service. At present, graphs and photographs are not retrievable, although it is possible that this material will also be transmissable soon.

644

GURNEY

TABLE

3:

AND

Costs

Database

Cost”

PLEASE

Number of Databases

Start5 F ee

Monthly

Mus.

$22 $15

0

0

$15 $32 $20 $22

Night

After Darkd BAKTHAU Day Night DIALOG

Knowledge

Indexd

MEDII

? FIND

LUNG

manuals)

$44

0

$28 $36

0

$75 $75

66 79

?FIND

$24

0

$35

Day

$23”

0

0

Night

$22

to

MEDLINE

current

file

195

(1444

articls

dcntlicd

usng

the

identifier

lung

disease)

UPPER UPPER

41

AND

51

6117

220 ?FIND

53

UPPEP

(fri

setl

and

text

word

upper

LOBE LOBE

52

AND

NOT

LOBE

LA=NONENGLISH

31 54

421062

1

C

I

0.10/reference

displayed, 0.10/search

LANONENGLISH

1 1 53 DISPLAY

displayed. 0.1 0/abstract

DISEASE

13745

13

manuals)

Includes telecommunications charge. Computer and modem pnces vary, systems range from $500-SOon. Includes 14 full-text journals and 35 full-text books.

b

LUNG

52 AND 53

0 ($50,

INDEX connect

Sb AND 52

$1 2

KNOWLEDGE

DISEASE

1444

?FIND

PaperChase

--“

TO

?BEGIN

6C

$125 ($50,

Day

10

1986

September

LOGON:

St

BRS /Colleague

AJR:147,

WELCOME

NLM Day Night

WIGTON

NOT

LANONENGLISH

54/SI/I-I

I (print

4th

changing

spectrum

of

set

foreign

(eliminate in

medium

format,

language articics

articlcs)

1-

1)

4/41/I

The

statement.

cystic

pulmonary

lesions

requiring

surgical

resection

in

infants. Schneider

New Methods

of Access

Department 3

Even with the standardized and easier-search languages, many users find the database services too difficult and too expensive. Two new types of products have appeared to address these problems: new on-line services and intelligent interface programs for the personal computer. Bibliographic

Retrieval

Services

offers

BRS/Colleague,

is using

an intelligent

interface

program

with

the personal

computer (Table 1 ). These programs, such as Pro-Search and Sci-Mate, not only take over the chores of gaffing connected to the on-line service, they also translate search requests into the special command language of the on-line service. The Sci-Mate Universal Online Searcher is a product of the Institute for Scientific Information, the producers of Current Contents and Science Citation Index. Sci-Mate offers a series of menu choices by which one can set up search strategies. Pro-Search

(previously

In-Search)

facilitates

searching

of

Tcr3c

rardiovisc

Journal

Code:

Cyr

JA;Thompson

Surgery,

University 5cr

(UNITED

TR:Sohnson of

DE;Burke

‘tinnesota

STATES),

BAtFoker

Hospitals, Mar

1985,

IE.

Minneapolis. 39

(3)

p332-9,ISSN

0022-

K93

an

on-line system with on-screen menus that requires far less training to get started and is excellent for the occasional user. A similar offering from DIALOG is Knowledge Index. Like Colleague, Knowledge Index is an on-line service that is easier to learn and use. For those concerned with the high price of searching, BRS offers BRS After Dark, which provides searching during off hours for substantially lower prices than daytime search. Another approach in easing access to the computer services

-5223

IR;St.

of

either Bibliographic Retrieval Services or DIALOG databases. Pro-Search users can call up comprehensive information about the organization, contents, and special features of each of the databases. Both programs save money by allowing one to prepare a search strategy before going on-line, both have facilities for downloading selected references to disk,

Fig. 3.-MEDLARS’ example from Fig. 2 was searched using MEDLINE database through Knowledge Index. Familiar English commands should be compared to commands from MEDLARS. Searching strategy is less inclusive than through MEDLARS. Eleven articles were identified, compared to 42 by MEDLARS. Search was completed in 18 mm and cost $6.89. User input is indicated by lines beginning with a question mark.

and both provide automatic dial-up and connection to the database. Several institutions have developed their own in-house searching capabilities by obtaining tapes of the MEDLINE database and loading them in their own systems. The most successful has been PaperChase, developed at Boston’s Beth Israel Hospital and now offered as a nationwide on-line service [7, 8]. Easy for the novice user, it offers some unique features such as the ability to restrict search results to the journals shelved in the local library. With the development of newer high-capacity data-storage media, such as the laser disk, searching locally held subsets of the MEDLINE database may soon become a popular alternative to on-line searching [9]. For each physician, the best system for access to the literature will be determined by anticipated frequency of use, cost, and individual needs. A recent study evaluating routes to the MEDLINE files found all systems capable of retrieving the pertinent articles addressing a given clinical problem

AJR:147,

September

COMPUTERIZED

1986

LITERATURE

[1 0]. As might be anticipated, differences existed in ease of use, cost, searching time, and the proportion of articles relevant to the topic. Keeping abreast of medical literature is a difficult task, but computerized searching makes it easier by allowing the individual radiologist easy rapid access to the databases.

REFERENCES

1 . Singer J, Sacks HS, Lucente F, Chalmers TC. Physician attitudes toward applications of computer data base systems. JAMA

1983:249:1610-1614 2. Ekstrand NL, Maynard mation

service

for

1983;1 41:1077-1080

CD, Sprinkle MD. A comprehensive an

academic

radiology

department.

inforAJR

3.

Miller

645

SEARCH

N, Kaye

D. The experience

of a department

of medicine

with a clinical medical library service. J Med Ed 1985;60:367373 4. Rowberg AH, Newell JD, Hunter TB. Telecomputing in radiology. AJR 1985;145:411-413 5. Wigton AS. Review of Sci-Mate Universal Online Searcher. Ann Intern Med 1984;100:621-622 6. Wigton AS. Review of In-Search. Ann Intern Med 1985;102: 566567 7. Horowitz GL, Bleich HL. Paperchase: a computer program to search the medical literature. N Engi J Med 1981;305:924-930 8. Horowitz GL, Jackson JD, Bleich HL. Paperchase self-service bibliographic retrieval. JAMA 1983;250:2494-2499 9. Crecine JP. The next generation of personal computers. Science

1986;231 :935-942 1 0. Haynes RB, McKibbon KA, Walker CJ, et al. Computer searching of the medical literature. Ann Intern Med 1985;1 03:812-816