Identification and description of controlled clinical trials published in Spanish Ophthalmology Journals

ABSTRACT

Purpose: Properly conducted controlled clinical trials (CCTs) provide the highest level of evidence for optimising decision-making in healthcare. Electronic search strategies do not exhaustively retrieve them, because of issues related to indexing, exclusion of journals in languages other than English, among others. A handsearch approach is therefore warranted. We aimed to identify all CCTs published in Ophthalmology journals in Spain, to describe their main features, and to submit them to the Cochrane Register of CCTs (CENTRAL).

Methods: After identifying all Spanish Ophthalmology Journals, we conducted a systematic handsearch following Cochrane guidelines. When appropriate, results were compared against electronic searches. A descriptive analysis was completed, including risk of bias assessment.

Results: We identified 18 eligible journals; 10 074 original articles, editorials, letters to the editor, abstracts and conference proceedings were assessed via handsearching for inclusion. Of these, 136 were subject to title and abstract screening, after which 102 were classified as CCTs. We identified three articles via electronic searches that had not been detected via handsearch, for a total of 105 CCTs. Among these, the most investigated pathologies were cataracts (32/105; 30.5%) and glaucoma (23/105 21.9%). Regarding risk of bias, 104/105 (99.0%) were deemed as “high risk of bias”, mainly due to flaws in sequence generation and allocation concealment. 15/105 (14.3%) mentioned conflicts of interest, half of which had something to declare. No CCT reported adherence to CONSORT.

Conclusion: Spanish Ophthalmology journals publish a low number of CCTs, with limited methodological quality. Handsearching was more sensitive than the electronic searching.

Abbreviations CCT: Controlled clinical trial

KEYWORDS:

• Controlled clinical trial
• handsearch
• ophthalmology
• randomised clinical trial
• systematic review

Supplemental data

Supplemental data for this article can be accessed here.

Acknowledgments

We would like to thank Cristina Puchol for entering data for submission to CENTRAL. We want to acknowledge Institut Barraquer, Instituto Ramón Castroviejo, Universidad Complutense de Madrid, Biblioteca de Óptica y Optometría, Universidad Complutense de Madrid, and Biblioteca Nacional de Catalunya for granting us access to the full-text versions of the handsearched journals.

Competing interests

None to declare.

Ethics approval

Not applicable since this study did not involve any patients.

Availability of data and materials

The dataset supporting the conclusions of this article is included within the article.

Author’s contributions

CL Designed the work, handsearched journals, analysed data and drafted the manuscript.

EM Designed the work, handsearched journals, analysed data, and drafted the manuscript.

CJ Handsearched journals

AD Handsearched journals.

HA Handsearched journals

EK Designed the work, provided specialty guidance.

HP Designed the work, analysed data, and contributed to the manuscript.

XB Designed the work and contributed to the manuscript.

Additional information

Funding

None to declare.