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Letter to E ditor
The initia l pub lic a tio ns1 o f the o ptima l search strateg y that was elabo rated co mbining hea ding s with text wo rd in three la ng ua g es, adapting the interface o f the LILACS, was based o n the o ptima l sea rc h stra teg y fo r MEDLIN E reco mmended by Co chrane Co llabo ratio n2 fo r id e ntific a tio n o f c linic a l tria ls in e le c tro nic databases. An impro vement and update to this search strateg y is no w presented. The Updated versio n o f this search strateg y will be fo und o n the website o f the Brazilian Co chrane Centre (http:/ / www.epm.br/ co chrane).
In the Table, we present the updated o ptimal search strategy to be used with LILACS/ CD-RO M, 3 2 nd editio n, September 1 9 9 8 . The strateg y is divided into the fo llo wing three stag es as defined in Dic ke rse n2 e t a l. a nd re p lic a te d in the Co chrane Handbo o k: stag e o ne (sets 1 to 9 ) includes terms with high precisio n; stage two (sets 1 0 to 2 8 ) includes terms with mo derate precisio n; and stag e three (sets 2 9 to 3 9 ) includes terms with lo w prec isio n b ut with o ptima l b ro wser sensitivity. The ma in differences fro m the o ld versio n are that the “ Ab” and “ Ti” expressio ns have bo th been changed into the “ Tw” expressio n in the search line-co ding .
Meanwhile, there are two items o f g o o d news:
a) the CD-RO M versio n o f the LILACS database ha s a W ind o w s inte rfa c e tha t so lve s the pro blems o f the DO S interface;
Optimal se arch strate gy
for clinical trials in the
Latin Ame rican and
Caribbe an He alth
Scie nce Lite rature
Database (LILACS
database ): Update
# 1 Pt RAN DO MIZED CO N TRO LLED TRIAL # 2 Pt CO N TRO LLED CLIN ICAL TRIAL # 3 Mh RAN DO MIZED CO N TRO LLED TRIALS # 4 Mh RAN DO M ALLO CATIO N
# 5 Mh DO UBLE-BLIN D METHO D # 6 Mh SIN G LE-BLIN D METHO D
# 7 # 1 O R # 2 O R # 3 O R # 4 O R # 5 O R # 6
# 8 Ct AN IMAL AN D N O T (Ct HUMAN and Ct AN IMAL) # 9 # 7 AN D N O T # 8
# 1 0 Pt CLIN ICAL TRIAL
# 1 1 Ex E0 5 .3 1 8 .7 6 0 .5 3 5 $ <explo de Mh CLIN ICAL TRIALS> # 1 2 Tw clin$ AN D (Tw trial$ O R Tw ensa$ O R Tw estud$ O R
Tw experim$ O R Tw investiga$ )
# 1 3 Tw singl$ O R Tw simple$ O R Tw do ubl$ O R Tw do ble$ O R Tw duplo $ O R Tw trebl$ O R Tw trip$
# 1 4 Tw blind$ O R Tw cego $ O R Tw ciego $ O R Tw mask$ O R Tw mascar$
# 1 5 # 1 8 # 1 3 AN D # 1 4 # 1 6 Mh PLACEBO S # 1 7 Tw placebo $
# 1 8 Tw rando m$ O R Tw rando n$ O R Tw casual$ O R Tw acaso $ O R Tw azar O R Tw aleato r$
# 1 9 Mh RESEARCH DESIG N
# 2 0 # 1 0 O R # 1 1 O R # 1 2 O R # 1 5 O R # 1 6 O R # 1 7 O R # 1 8 O R # 1 9
# 2 1 Ct AN IMAL AN D N O T (Ct HUMAN and Ct AN IMAL) # 2 2 # 2 0 AN D N O T # 2 1
# 2 3 # 2 2 AN D N O T # 9 # 2 4 Ct CO MPARATIVE STUDY
# 2 5 Ex E0 5 .3 3 7 $ <explo de Mh EVALUATIO N STUDIES)> # 2 6 Mh FO LLO W -UP STUDIES
# 2 7 Mh PRO SPECTIVE STUDIES
# 2 8 Tw co ntro l$ O R Tw pro spectiv$ O R Tw vo lunt$ O R Tw vo l-unteer$
# 2 9 # 2 4 O R # 2 5 O R # 2 6 O R # 2 7 O R # 2 8
# 3 0 Ct AN IMAL AN D N O T (Ct HUMAN and Ct AN IMAL) # 3 1 # 2 9 AN D N O T # 3 0
# 3 2 # 3 1 AN D N O T (# 9 O R # 2 3 ) # 3 3 # 9 O R # 2 3 O R # 3 2
Table - Optimal search strategy for RCT/ CCT in the LILACS Bireme interface, 3 2 nd edition
· Upper case deno tes co ntro lled vo cabulary. · Lo wer case deno tes free-text terms.
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b) the Lilacs database is free o n the BIREME we b site (http:/ / www.b ire me .b r) to g e the r w ith the o the r d a ta b a se s o f BIREM E Publishing , but available o nly in Po rtug uese and Spanish lang uag es. These features will help to facilitate access to Latin American and Caribbean Health Science Literature.
Sao Paulo Med J/Rev Paul Med 1999; 117(3):138-9.
2. Dickersin K, Larso n K. Establishing and maintaining an internatio nal register o f RCTs. In: Co chrane Co llabo ratio n Handbo o k. Oxfo rd: The Co chrane Co llabo ratio n, 1997 [updated September 1997]. Available in: The Co chrane Library [database o n disk and CDROM]. Oxfo rd: Update So ftware, 1997; Issue 3. Updated quarterly. Available fro m: BMJ Publishing Gro up, Lo ndo n.
3. Castro AA, Atallah AN, Clark OA. Lo cating and appraising system-atic reviews [letter; co mment]. Ann Intern Med 1998;128(4):322-3. Co mment o n: Ann Intern Med 1997;126(7):532-8.
Aldema r Ara ujo Ca stro - MD, MChir. Universidade Federal de São Paulo , Brazil.
Otá vio Augusto Câ ma ra Cla rk - MD. Universidade Estadual de Campinas, Brazil.
Álva ro N a gib Ata lla h - MD, PhD. Universidade Federal de São Paulo , Brazil.
Conflict of interest: N o t declared.
