Choosing between measures: comparison of EQ-5D, HUI2 and HUI3 in persons with hearing complaints

OBJECTIVES: To generate insight into the differences between utility measures EuroQol 5D (EQ-5D), Health Utilities Index Mark II (HUI2) and Mark III (HUI3) and their impact on the incremental cost-effectiveness ratio (ICER) for hearing aid fitting METHODS: Persons with hearing complaints completed EQ-5D, HUI2 and HUI3 at baseline and, when applicable, after hearing aid fitting. Practicality, construct validity, agreement, responsiveness and impact on the ICER were examined. RESULTS: All measures had high completion rates. HUI3 was capable of discriminating between clinically distinctive groups. Utility scores (n = 315) for EQ-5D UK and Dutch tariff (0.83; 0.86), HUI2 (0.77) and HUI3 (0.61) were significantly different, agreement was low to moderate. Change after hearing aid fitting (n = 70) for HUI2 (0.07) and HUI3 (0.12) was statistically significant, unlike the EQ-5D UK (0.01) and Dutch (0.00) tariff. ICERs varied from 647,209 euros/QALY for the EQ-5D Dutch tariff to 15,811 euros/QALY for HUI3. CONCLUSION: Utility scores, utility gain and ICERs heavily depend on the measure that is used to elicit them. This study indicates HUI3 as the instrument of first choice when measuring utility in a population with hearing complaints, but emphasizes the importance of a clear notion of what constitutes utility with regard to economic analyse

Indirect interactions in the High Arctic

Peer reviewe

Late Holocene dust provenance at Siple Dome, Antarctica

International audienceCompositions of mineral dust in ice cores serve as tracers of paleo-atmospheric circulation patterns, providing linkages between sources and sinks. Here we document the geochemical makeup of dust reaching continental West Antarctica, on late Holocene samples from the Siple Dome A ice core (spanning ∼1030-1800 C.E). The Nd-Sr isotope signature is unusual for Antarctic ice core dust samples. Siple Dome data are characterized by low Nd isotope ratios (as low as εNd = -16.3) along with low Sr isotope ratios (highest 87Sr/86Sr = 0.7102) compared with other Antarctic dust signatures. A well-defined inverse correlation between Sr-Nd isotope ratios indicates two primary mixing sources. The low εNd-values indicate involvement of ancient (Archean-to-early Proterozoic) continental crust, as either the direct source or as a precursor of the source, and the low Sr-values require low Rb/Sr ratios that often reflect high-grade metamorphism. The known Antarctic terrane with these characteristics is parts of Enderby Land, nearly at the opposite end of Antarctica. The isotopic signature of the second end-member is compatible with West Antarctic volcanoes or Patagonia in South America. The Sr-Nd isotopes and trace element abundances are also chemically compatible with mixing between volcanic material from Gaussberg, a small lamproite volcano in Kaiser Wilhelm II Land in coastal East Antarctica whose source is ancient lithospheric mantle, with dust from Patagonia or material from West Antarctic volcanoes. We assess these potential mixing scenarios and conclude that Siple Dome's unusual geochemical signature can best be explained by a mixture of Patagonian dust and a Gaussberg-like source, with additional minor contributions from old eroded Archean-to-early Proterozoic bedrock sources such as those in Enderby Land. Moreover, Siple Dome dust compositions are distinct from dust deposited on Taylor and Clark Glaciers in the McMurdo Dry Valleys of the western Ross Sea, precluding the Dry Valleys as a late Holocene dust source to this region of the eastern Ross Sea