A Systematic Review of Studies Comparing the Measurement Properties of the Three-Level and Five-Level Versions of the EQ-5D

Background: Since the introduction of the five-level version of the EQ-5D (5L), many studies have comparatively investigated the measurement properties of the original three-level version (3L) with the 5L version. Objective: The aim of this study was to consolidate the available evidence on the performance of both instruments. Methods: A systematic literature search of studies in the English and German languages was conducted (2007–January 2018) using the PubMed, EMBASE, and PsycINFO (EBSCO) databases, as well as the EuroQol Research Foundation website. Data were extracted and assessed on missing values, distributional properties, informativity indices (Shannon’s H′ and J′), inconsistencies, responsiveness, and test–retest reliability. Results: Twenty-four studies were included in the review. Missing values and floor effects (percentage reporting the worst health state) were found to be negligible for both 3L and 5L (< 5%). From 18 studies, inconsistencies ranged from 0 to 10.6%, although they were generally well below 5%, with 9 studies reporting the most inconsistencies for Usual Activities (mean percentage 4.1%). Shannon’s indices were always higher for 5L than for 3L, and all but three studies reported lower ceiling effects (‘11111’) for 5L than for 3L. There is mixed and insufficient evidence on responsiveness and test–retest reliability, although results on index values showed better performance for 5L on test–retest reliability. Conclusion: Overall, studies showed similar or better measurement properties of the 5L compared with the 3L, and evidence indicated moderately better distributional parameters and substantial improvement in informativity for the 5L compared with the 3L. Insufficient evidence on responsiveness and test–retest reliability implies further research is needed

Magnetization reversal of an individual exchange biased permalloy nanotube

We investigate the magnetization reversal mechanism in an individual permalloy (Py) nanotube (NT) using a hybrid magnetometer consisting of a nanometer-scale SQUID (nanoSQUID) and a cantilever torque sensor. The Py NT is affixed to the tip of a Si cantilever and positioned in order to optimally couple its stray flux into a Nb nanoSQUID. We are thus able to measure both the NT's volume magnetization by dynamic cantilever magnetometry and its stray flux using the nanoSQUID. We observe a training effect and temperature dependence in the magnetic hysteresis, suggesting an exchange bias. We find a low blocking temperature $T_B = 18 \pm 2$ K, indicating the presence of a thin antiferromagnetic native oxide, as confirmed by X-ray absorption spectroscopy on similar samples. Furthermore, we measure changes in the shape of the magnetic hysteresis as a function of temperature and increased training. These observations show that the presence of a thin exchange-coupled native oxide modifies the magnetization reversal process at low temperatures. Complementary information obtained via cantilever and nanoSQUID magnetometry allows us to conclude that, in the absence of exchange coupling, this reversal process is nucleated at the NT's ends and propagates along its length as predicted by theory.Comment: 8 pages, 4 figure

Hyperglycemia and nocturnal systolic blood pressure are associatedwith left ventricular hypertrophy and diastolic dysfunction in hypertensive diabetic patients

BACKGROUND: The aim of this study was to determine if hypertensive type 2 diabetic patients, when compared to patients with essential hypertension have an increased left ventricular mass index (LVMI) and a worse diastolic function, and if this fact would be related to 24-h pressoric levels changes. METHODS: Ninety-one hypertensive patients with type 2 diabetes mellitus (DM) (group-1 [G1]), 59 essential hypertensive patients (group-2 [G2]) and 26 healthy controls (group-3 [G3]) were submitted to 24-h Ambulatory Blood Pressure Monitoring (ABPM) and echocardiography (ECHO) with Doppler. We calculated an average of fasting blood glucose (AFBG) values of G1 from the previous 4.2 years and a glycemic control index (GCI) (percentual of FBG above 200 mg/dl). RESULTS: G1 and G2 did not differ on average of diurnal systolic and diastolic BP. However, G1 presented worse diastolic function and a higher average of nocturnal systolic BP (NSBP) and LVMI (NSBP = 132 ± 18 vs 124 ± 14 mmHg; P < 0.05 and LVMI = 103 ± 27 vs 89 ± 17 g/m(2); P < 0.05, respectively). In G1, LVMI correlated with NSBP (r = 0.37; P < 0.001) and GCI (r = 0.29; P < 0.05) while NSBP correlated with GCI (r = 0.27; P < 0.05) and AFBG (r = 0.30; P < 0.01). When G1 was divided in tertiles according to NSBP, the subgroup with NSBP≥140 mmHg showed a higher risk of LVH. Diabetics with NSBP≥140 mmHg and AFBG>165 mg/dl showed an additional risk of LVH (P < 0.05; odds ratio = 11). In multivariate regression, both GCI and NSBP were independent predictors of LVMI in G1. CONCLUSION: This study suggests that hyperglycemia and higher NSBP levels should be responsible for an increased prevalence of LVH in hypertensive patients with Type 2 DM

Superconducting quantum interference devices with submicron Nb/HfTi/Nb junctions for investigation of small magnetic particles

We investigated, at temperature $4.2\,\mathrm{K}$, electric transport, flux noise and resulting spin sensitivity of miniaturized Nb direct current superconducting quantum interference devices (SQUIDs) based on submicron Josephson junctions with HfTi barriers. The SQUIDs are either of the magnetometer-type or gradiometric in layout. In the white noise regime, for the best magnetometer we obtain a flux noise $S_{\Phi}^{1/2}=250\,\mathrm{n}\Phi_0/\mathrm{Hz}^{1/2}$, corresponding to a spin sensitivity $S^{1/2}_\mu\,\ge\,29\,\mu_B/\mathrm{Hz}^{1/2}$. For the gradiometer we find $S_{\Phi}^{1/2}=300\,\mathrm{n}\Phi_0/\mathrm{Hz}^{1/2}$ and $S^{1/2}_\mu\,\ge\,44\,\mu_B/\mathrm{Hz}^{1/2}$. The devices can still be optimized with respect to flux noise and coupling between a magnetic particle and the SQUID, leaving room for further improvement towards single spin resolution.Comment: 4 pages, 3 figure

Scoring the EQ-HWB-S: can we do it without value sets? A non-parametric item response theory analysis

Background Only one pilot value set (UK) is currently available for the EQ Health and Wellbeing Instrument short version (EQ-HWB-S). As an alternative to preference-weighted scoring, we examined whether a level summary score (LSS) is appropriate for the EQ-HWB-S using Mokken scaling analyses. Methods Data from patients, carers and the general population collected during the developmental phase of the EQ-HWB-S in Australia, US and UK were used, noting 3 of 9 items have since undergone revision. EQ-HWB-S data fit was examined using R package Mokken scaling’s monotone homogeneity model, utilizing the automated item selection procedure (AISP) as well as Loevinger’s scaling coefficients for items and the scale (HS). Manifest monotonicity was assessed by examining whether the cumulative probability for responses at or above each response level did not decrease across the summary score. Results EQ-HWB-S data were available for 3340 respondents: US = 903, Australia = 514 and UK = 1923. Mean age was 50 ± 18 and 1841 (55%) were female. AISP placed all 9 items of the EQ-HWB-S on a single scale when the lower bound was set to < 0.448. Strong scalability (HS = 0.561) was found for the EQ-HWB-S as a single scale. Stronger scales were formed by separating the psychosocial items (n = 6, HS = 0.683) and physical sensation items (n = 3, HS = 0.713). No violations of monotonicity were found except for the items mobility and daily activities for the subgroups with long-term conditions and UK subjects, respectively. Discussion As EQ-HWB-S items formed a strong scale and subscales based on Mokken analysis, LSS is a promising weighting-free approach to scoring

Psychometric properties of the EQ-5D-5L: a systematic review of the literature

Purpose: Although the EQ-5D has a long history of use in a wide range of populations, the newer five-level version (EQ-5D-5L) has not yet had such extensive experience. This systematic review summarizes the available published scientific evidence on the psychometric properties of the EQ-5D-5L. Methods: Pre-determined key words and exclusion criteria were used to systematically search publications from 2011 to 2019. Information on study characteristics and psychometric properties were extracted: specifically, EQ-5D-5L distribution (including ceiling and floor), missing values, reliability (test–retest), validity (convergent, known-groups, discriminate) and responsiveness (distribution, anchor-based). EQ-5D-5L index value means, ceiling and correlation coefficients (convergent validity) were pooled across the studies using random-effects models. Results: Of the 889 identified publications, 99 were included for review, representing 32 countries. Musculoskeletal/orthopedic problems and cancer (n = 8 each) were most often studied. Most papers found missing values (17 of 17 papers) and floor effects (43 of 48 papers) to be unproblematic. While the index was found to be reliable (9 of 9 papers), individual dimensions exhibited instability over time. Index values and dimensions demonstrated moderate to strong correlations with global health measures, other multi-attribute utility instruments, physical/functional health, pain, activities of daily living, and clinical/biological measures. The instrument was not correlated with life satisfaction and cognition/communication measures. Responsiveness was addressed by 15 studies, finding moderate effect sizes when confined to studied subgroups with improvements in health. Conclusions: The EQ-5D-5L exhibits excellent psychometric properties across a broad range of populations, conditions and settings. Rigorous exploration of its responsiveness is needed