Handsearching of randomised clinical trials published in Spanish journals in ophthalmology

Article type
Authors
Madrid E1, Loezar C2, Pardo H3, Bonfill X3, Daviu A4, Jahr C4, Ahumada H4, Keller E5
1Department of Public Health, School of Medicine, Universidad de Valparaiso, Chile. Iberoamerican Cochrane Centre, Barcelona, Spain, Chile
2Department of Ophthalmology, School of Medicine, Universidad de Valparaiso , Chile
3Iberoamerican Cochrane Centre, Barcelona, Spain, Chile
4School of Medicine, Universidad de Valparaiso, Chile
5Department of Ophthalmology, School of Medicine, Universidad de Valparaiso , Chile
Abstract
Introduction: Randomised clinical trials (RCTs) provide the highest level of evidence for optimising decision-making in healthcare. However, electronic searching does not guarantee access to all of them, since main databases and search engines do not include all journals in different specialties and languages.
Objectives: To identify and retrieve RCTs published in ophthalmology journals in Spain, using the Cochrane handsearching protocol, to assess quality and include them in the Cochrane Central Register of Controlled Trials.
Methods: After identifying all Spanish ophthalmology journals, systematic handsearching was performed to retrieve RCTs. We reviewed titles and abstracts of original articles, letters, and conference presentations in every journal. The recommended steps were: a) reading the table of contents, b) locating keywords, c) reading the abstract, d) reading the methods section in the full text. We searched retrospectively starting backwards from the latest published issue. If no RCTs were identified over five consecutive years, handsearching was stopped for that journal. After identification and retrieval of all RCTs, a methodological assessment was performed using the tools for risk of bias published by Cochrane.
Results: Eighteen journals were identified; 9309 articles were assessed by title/abstract by four reviewers; 137 articles were identified as potential RCTs, and 98 were finally included after reading the full-text. The journal with the highest number of published RCTs was 'Archivos de la Sociedad Española de Oftalmología' (72 clinical trials) from 1971 to 2014. From the RCTs identified and confirmed from the full text, 68.3% were conducted in a single center, and 48.8% were performed in hospital settings. The most investigated topic was glaucoma (29.27%). With regard to risk of bias, 80.5 % of the studies were assessed as being at high risk.
Conclusions: Spanish ophthalmology journals publish a low number of RCTs. The quality of the reports were assessed as being at high risk of bias in a high proportion of them. This was mainly due to flaws in the randomisation process, allocation concealment and low rate of blinding.