DESIGN: AVERT is a prospective, parallel group, assessor-blinded randomised clinical trial. This paper presents data assessing the generalisability of AVERT.
SETTING: Acute stroke units at 44 hospitals in 8 countries.
PARTICIPANTS: The first 20,000 patients screened for AVERT, of whom 1158 were recruited and randomised.
MODEL: We use the Proximal Similarity Model, which considers the person, place, and setting and practice, as a framework for considering generalisability. As well as comparing the recruited patients with the target population, we also performed an exploratory analysis of the demographic, clinical, site and process factors associated with recruitment.
RESULTS: The demographics and stroke characteristics of the included patients in the trial were broadly similar to population-based norms, with the exception that AVERT had a greater proportion of men. The most common reason for non-recruitment was late arrival to hospital (ie, >24 h). Overall, being older and female reduced the odds of recruitment to the trial. More women than men were excluded for most of the reasons, including refusal. The odds of exclusion due to early deterioration were particularly high for those with severe stroke (OR=10.4, p<0.001, 95% CI 9.27 to 11.65).
CONCLUSIONS: A model which explores person, place, and setting and practice factors can provide important information about the external validity of a trial, and could be applied to other clinical trials.
TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12606000185561) and Clinicaltrials.gov (NCT01846247).
METHODS: Four questions and their corresponding response options were adapted from existing population-based surveys to assess tinnitus prevalence, tinnitus symptom severity, use of healthcare resources for tinnitus and hearing difficulty. The translated versions (Bulgarian, French, German, Greek, Italian, Latvian, Polish, Portuguese, Romanian, Russian, and Spanish) were generated using recognized methods to achieve a "world-for-world" translation.
RESULTS: Translated versions were produced with acceptable functional equivalence to the original English-language version, as judged by a small panel of bilingual speakers who participated in the online field testing.
CONCLUSION: This work is the first of its kind to promote multi-national standardization by creating a set of tools that can readily be used across countries. These are currently being used in a European-wide study of tinnitus prevalence, and have wider application across English- and Spanish speaking countries including the Americas and Oceania.
METHODOLOGY: Tracheal aspirates were obtained from neonates on ventilatory support. The SM test was carried out on specimens of tracheal aspirate immediately after collection. Levels of SP-A in tracheal aspirates were determined by enzyme-linked immunosorbent assay (ELISA) method. The results of the SM test and SP-A level of the tracheal aspirates were compared against the clinical diagnosis of RDS based on clinical, radiological and bacteriological findings.
RESULTS: Both the median microbubble counts (6 microbubbles/mm2, range = 0-90) and median SP-A levels (100 micrograms/L, range = 0-67447) of infants with RDS were significantly lower than those of infants with no obvious lung pathology (P < 0.0001), and pneumonia (P < 0.0001). The SM test of tracheal aspirates had higher overall accuracy for the diagnosis of RDS than measurement of SP-A levels (94.6% vs 82.4%). When the receiver operating characteristic (ROC) curves of both tests for RDS were compared, the area under the ROC curve of the SM test was larger (0.9689) than that of the SP-A method (0.8965).
CONCLUSIONS: This study showed that the SM test of tracheal aspirate was a useful bedside diagnostic test for RDS. It could be carried out at any time after birth on infants requiring ventilatory support.