Validity assumptions for a multiple-choice test of medical knowledge with open-books and web access. A known groups comparison study.

Relatively little evidence about the validity threats in open-book multiple-choice tests exist. The aim of this study was to examine validity aspects relating to gener-alization, extrapolation and decision of a multiple-choice test of medical knowledge with aids (open-book and internet access). The theoretical framework was modern validity theory, and the study was designed as a ‘known groups com-parison’ study. Test performances of three known groups of test takers hypothe-sized to have different knowledge levels of the test content were compared, and analysis of pass/fail decisions was used to examine implications of decisions based on test scores. Results indicated that it was possible to discriminate between expert and non-expert test taker groups even with the access to aids. In contrast, an inde-fensible passing score was found to be the largest potential threat to test validity. Relatively little evidence about the validity threats in open-book multiple-choice tests exist. The aim of this study was to examine validity aspects relating to gener-alization, extrapolation and decision of a multiple-choice test of medical knowledge with aids (open-book and internet access). The theoretical framework was modern validity theory, and the study was designed as a ‘known groups com-parison’ study. Test performances of three known groups of test takers hypothe-sized to have different knowledge levels of the test content were compared, and analysis of pass/fail decisions was used to examine implications of decisions based on test scores. Results indicated that it was possible to discriminate between expert and non-expert test taker groups even with the access to aids. In contrast, an inde-fensible passing score was found to be the largest potential threat to test validity.&nbsp

PET/CT without capacity limitations: a Danish experience from a European perspective

# The Author(s) 2011. This article is published with open access at Springerlink.com Objectives We report the 3-year clinical experience of a large new Danish PET/CT centre without capacity limitations in relation to national and European developments. Methods The use of PET/CT in cancer was registered from early 2006 to early 2009 to judge the impact on patient management and to compare it with national and European trends. Results 6056 PET/CT examinations were performed in 4327 patients. Activity increased by 86 examinations per month compared with the same month the year before. Referrals came primarily from oncology (23.0%), haematology (21.6%), surgery (12.6%), internal medicine (12.7%) and gynaecology (5.5%). Referral indications were diagnosis (31.3%), staging (22.3%), recurrence detection (21.2%), response evaluation (17.0%) and other (8.2%). Response from nearly 60 % of users showed that PET/CT caused a change in diagnosis and/or staging and/or treatment plan in 36.0 % of cases. During the study period, there was a steep increase in the national use of FDG and in the European use of PET/CT. Conclusions We recorded a constantly increasing use of PET/CT that caused a change in diagnosis and/or stagin