Revista chilena de cirugía
versión On-line ISSN 0718-4026
MANTEROLA D, CARLOS et al. Internal and external validity of a clinical trial reporting the use of albendazole for the treatment of hydatidosis. Rev Chil Cir [online]. 2008, vol.60, n.2, pp. 132-138. ISSN 0718-4026. doi: 10.4067/S0718-40262008000200009.
Background: Classic treatment of echinococcosis is surgery. The study of Keshmiri raises the use of albendazole as an alternative. Aim: To determine internal and external validity of the Keshmiri study. Material and methods: Four instruments that assess methodological quality, were applied to the manuscript. A critical reading was done and the internal and external validity of the methodological quality was analyzed with three scales: Methodology and Research in Surgery (MINCIR), Consolidated Standards of Reporting Trials (CONSORT) and Scottish Intercollegiate Guidelines Network (SIGN). Guides and scales were applied by 7 researchers with training in clinical epidemiology. Results: The Keshmiri study has not a specific objective. The method used for random assignment is not described and not all patients were assessed at the end of the study due to a loss form follow up of 23% of patients in drug branch and 43% in the placebo branch. MINCIR scale identified a blinded randomized clinical trial, with an unclear randomized sequence, without sample size estimation and vague objectives. CONSORT proved the lack of working hypothesis and specific objectives as well as an absence of identification of the primary variable, absence of sample size calculation, ambiguities in the randomization process, absence of statistical adjustment and the omission of a subgroup analysis. SIGN verified the same methodological errors. Conclusions: The applied instruments found methodological deficiencies that jeopardize the internal and external validity of the study
Palabras clave : Echinococcosis; Hepatic Echinococcosis; Hepatic Hydatid Cyst; Albendazole (MeSH); Albendazole/therapeutic use (MeSH); Methodological studies (Multi); Methodological study (Multi); Evidence-Based Medicine (MeSH).