Reliability and validity of PROMIS measures administered by telephone interview in a longitudinal localized prostate cancer study

Purpose: To evaluate the reliability and validity of six PROMIS measures (anxiety, depression, fatigue, pain interference, physical function, and sleep disturbance) telephone-administered to a diverse, population-based cohort of localized prostate cancer patients. Methods: Newly diagnosed men were enrolled in the North Carolina Prostate Cancer Comparative Effectiveness and Survivorship Study. PROMIS measures were telephone-administered pre-treatment (baseline), and at 3-months and 12-months post-treatment initiation (N = 778). Reliability was evaluated using Cronbach’s alpha. Dimensionality was examined with bifactor models and explained common variance (ECV). Ordinal logistic regression models were used to detect potential differential item functioning (DIF) for key demographic groups. Convergent and discriminant validity were assessed by correlations with the legacy instruments Memorial Anxiety Scale for Prostate Cancer and SF-12v2. Known-groups validity was examined by age, race/ethnicity, comorbidity, and treatment. Results: Each PROMIS measure had high Cronbach’s alpha values (0.86–0.96) and was sufficiently unidimensional. Floor effects were observed for anxiety, depression, and pain interference measures; ceiling effects were observed for physical function. No DIF was detected. Convergent validity was established with moderate to strong correlations between PROMIS and legacy measures (0.41–0.77) of similar constructs. Discriminant validity was demonstrated with weak correlations between measures of dissimilar domains (−0.20–−0.31). PROMIS measures detected differences across age, race/ethnicity, and comorbidity groups; no differences were found by treatment. Conclusions: This study provides support for the reliability and construct validity of six PROMIS measures in prostate cancer, as well as the utility of telephone administration for assessing HRQoL in low literacy and hard-to-reach populations

Measurement of the Neutron Spin Structure Function g1ng_1^n with a Polarized ^3He Target

Results are reported from the HERMES experiment at HERA on a measurement of the neutron spin structure function $g_1^n(x,Q^2)$ in deep inelastic scattering using 27.5 GeV longitudinally polarized positrons incident on a polarized $^3$He internal gas target. The data cover the kinematic range $0.023<x<0.6$ and $1 (GeV/c)^2 < Q^2 <15 (GeV/c)^2$. The integral $\int_{0.023}^{0.6} g_1^n(x) dx$ evaluated at a fixed $Q^2$ of $2.5 (GeV/c)^2$ is $-0.034\pm 0.013(stat.)\pm 0.005(syst.)$. Assuming Regge behavior at low $x$, the first moment $\Gamma_1^n=\int_0^1 g_1^n(x) dx$ is $-0.037\pm 0.013(stat.)\pm 0.005(syst.)\pm 0.006(extrapol.)$.Comment: 4 pages TEX, text available at http://www.krl.caltech.edu/preprints/OAP.htm

The HERMES Spectrometer

The HERMES experiment is collecting data on inclusive and semi-inclusive deep inelastic scattering of polarised positrons from polarised targets of Il, D, and He-3. These data give information on the spin structure of the nucleon. This paper describes the forward angle spectrometer built for this purpose. The spectrometer includes numerous tracking chambers (micro-strip gas chambers, drift and proportional chambers) in front of and behind a 1.3 T.m magnetic field, as well as an extensive set of detectors for particle identification (a lead-glass calorimeter, a pre-shower detector, a transition radiation detector, and a threshold Cherenkov detector). Two of the main features of the spectrometer are its good acceptance and identification of both positrons and hadrons, in particular pions. These characteristics, together with the purity of the targets, are allowing HERMES to make unique contributions to the understanding of how the spins of the quarks contribute to the spin of the nucleon. (C) 1998 Elsevier Science B.V. All rights reserved