Article type
Year
Abstract
Introduction: Hand search activities are central to the Cochrane Collaboration's goal of the systematic collection of randomized and controlled trials. The proper generation of systematic reviews requires the identification of the maximum number of potentially relevant studies.
Objective: Assess levels of current, registered hand search activities with specific focus on the identification of publications yielding a high proportion of randomized controlled trials (RCTs) indexed in MEDLINE.
Methods: Descriptive analysis of current hand search activities registered with the Baltimore Cochrane Center using the MEDLINE and Master List databases. This study compared the number of citations in MELINE (Ovid) tagged with the publication type "randomized controlled trial" with the Collaboration's Master List of Journals Being Searched (Master List, current for 19 March 1998) as a measure of current search efforts. Univariate and trend analyses were performed on citations retrieved from the 1987 - January 1998 MEDLINE database. Journals containing identified citations were ranked annually and over the entire period, and were subsequently compared to the Master List database. A reassessment is planned prior to October 1998.
Results: We retrieved 75,012 citations tagged as RCTs published in 2,671 journals. These RCTs represented 9.45% of all citations from 1987 to January 1998. The mean (+- SD) number of RCTs per year was 6,819.3 (+- ,2029.6). Poisson regression analysis showed a statistically significant 7.6% crude annual increase in the number of RCTs (95% CI = 7.35 to 7.87) for the period. The top 101 journals were selected and compared to the Master List, identifying 83 journals currently registered as being searched. Seventy-seven of the 83 registered journals were listed as having undergone full examination; and 51 were listed as currently undergoing a prospective search.
Discussion: The current level of hand search activity captures about 82% of its potential yield; 18 of the top 101 journals ranked by number of RCTs published are not currently registered as being searched by the Collaboration. Hand-searching of all journals identified as high-yield sources of RCTs is an essential step in the identification of the maximum number of trials that may be relevant for inclusion in Cochrane Reviews.
Objective: Assess levels of current, registered hand search activities with specific focus on the identification of publications yielding a high proportion of randomized controlled trials (RCTs) indexed in MEDLINE.
Methods: Descriptive analysis of current hand search activities registered with the Baltimore Cochrane Center using the MEDLINE and Master List databases. This study compared the number of citations in MELINE (Ovid) tagged with the publication type "randomized controlled trial" with the Collaboration's Master List of Journals Being Searched (Master List, current for 19 March 1998) as a measure of current search efforts. Univariate and trend analyses were performed on citations retrieved from the 1987 - January 1998 MEDLINE database. Journals containing identified citations were ranked annually and over the entire period, and were subsequently compared to the Master List database. A reassessment is planned prior to October 1998.
Results: We retrieved 75,012 citations tagged as RCTs published in 2,671 journals. These RCTs represented 9.45% of all citations from 1987 to January 1998. The mean (+- SD) number of RCTs per year was 6,819.3 (+- ,2029.6). Poisson regression analysis showed a statistically significant 7.6% crude annual increase in the number of RCTs (95% CI = 7.35 to 7.87) for the period. The top 101 journals were selected and compared to the Master List, identifying 83 journals currently registered as being searched. Seventy-seven of the 83 registered journals were listed as having undergone full examination; and 51 were listed as currently undergoing a prospective search.
Discussion: The current level of hand search activity captures about 82% of its potential yield; 18 of the top 101 journals ranked by number of RCTs published are not currently registered as being searched by the Collaboration. Hand-searching of all journals identified as high-yield sources of RCTs is an essential step in the identification of the maximum number of trials that may be relevant for inclusion in Cochrane Reviews.