396 research outputs found
The Importance of Rating Scale Design in the Measurement of Patient-Reported Outcomes Using Questionnaires or Item Banks
This article is made available with the permission of the publisher, Association for Research in Vision and OphthalmologyPurpose.: To investigate the effect of rating scale designs (question formats and response categories) on item difficulty calibrations and assess the impact that rating scale differences have on overall vision-related activity limitation (VRAL) scores.
Methods.: Sixteen existing patient-reported outcome instruments (PROs) suitable for cataract assessment, with different rating scales, were self-administered by patients on a cataract surgery waiting list. A total of 226 VRAL items from these PROs in their native rating scales were included in an item bank and calibrated using Rasch analysis. Fifteen item/content areas (e.g., reading newspapers) appearing in at least three different PROs were identified. Within each content area, item calibrations were compared and their range calculated. Similarly, five PROs having at least three items in common with the Visual Function (VF-14) were compared in terms of average item measures.
Results.: A total of 614 patients (mean age ± SD, 74.1 ± 9.4 years) participated. Items with the same content varied in their calibration by as much as two logits; “reading the small print” had the largest range (1.99 logits) followed by “watching TV” (1.60). Compared with the VF-14 (0.00 logits), the rating scale of the Visual Disability Assessment (1.13 logits) produced the most difficult items and the Cataract Symptom Scale (0.24 logits) produced the least difficult items. The VRAL item bank was suboptimally targeted to the ability level of the participants (2.00 logits).
Conclusions.: Rating scale designs have a significant effect on item calibrations. Therefore, constructing item banks from existing items in their native formats carries risks to face validity and transmission of problems inherent in existing instruments, such as poor targeting
Identifying Content for the Glaucoma-specific Item Bank to Measure Quality-of-life Parameters
"This is a non-final version of an article published in final form in Khadka J, McAlinden C, Craig JE, Fenwick EK, Lamoureux EL, Pesudovs K. Identifying content for the glaucoma-specific item bank to measure quality-of-life parameters. Journal of Glaucoma . 2015 Jan;24(1):12-9. doi: 10.1097/IJG.0b013e318287ac11.". Author manuscript version made available in accordance with publisher copyright policy.PURPOSE:
Patient-reported outcomes (PROs) have become essential clinical trial end points. However, a comprehensive, multidimensional, patient-relevant, and precise glaucoma-specific PRO instrument is not available. Therefore, the purpose of this study was to identify content for a new, glaucoma-specific, quality-of-life (QOL) item bank.
METHODS:
Content identification was undertaken in 5 phases: (1) identification of extant items in glaucoma-specific instruments and the qualitative literature; (2) focus groups and interviews with glaucoma patients; (3) item classification and selection; (4) expert review and revision of items; and (5) cognitive interviews with patients.
RESULTS:
A total of 737 unique items (extant items from PRO instruments, 247; qualitative articles, 14 items; focus groups and semistructured interviews, 476 items) were identified. These items were classified into 10 QOL domains. Four criteria (item redundancy, item inconsistent with domain definition, item content too narrow to have wider applicability, and item clarity) were used to remove and refine the items. After the cognitive interviews, the final minimally representative item set had a total of 342 unique items belonging to 10 domains: activity limitation (88), mobility (20), visual symptoms (19), ocular surface symptoms (22), general symptoms (15), convenience (39), health concerns (45), emotional well-being (49), social issues (23), and economic issues (22).
CONCLUSIONS:
The systematic content identification process identified 10 QOL domains, which were important to patients with glaucoma. The majority of the items were identified from the patient-specific focus groups and semistructured interviews suggesting that the existing PRO instruments do not adequately address QOL issues relevant to individuals with glaucoma
Visual and refractive outcomes following implantation of a new trifocal intraocular lens.
BACKGROUND: Independence from all optical aids, and freedom from unwanted symptoms, following cataract and lens surgery remains the ultimate goal of both patient and surgeon. The development of trifocal IOL technology provides an ever-increasing range of options. The purpose of our study is to understand the predictability, safety and efficacy of a new trifocal intraocular lens (IOL) following cataract or refractive lens exchange (RLE) surgery. METHODS: This was a retrospective consecutive case series of patients undergoing cataract extraction or RLE followed by implantation of the Alcon IQ Panoptix IOL. Pre and postoperative refractive and visual parameters were recorded and evaluated. As the cohort followed a normal distribution, standard parametric tests were used. Paired t-test was used to compare the difference between target and postoperative refractive errors. The incidence of intraoperative and postoperative complications was also reported. RESULTS: The IOL was implanted in 66 eyes of 33 patients. Mean postoperative spherical equivalent (SE) refraction was -0.08 ± 0.25 dioptres (D). This was not significantly different from the target refraction (p = 0.841). Sixty-five percent of patients were within ± 0.25 D of the target SE refraction with 100% within ± 0.50 D of intended correction. Mean postoperative uncorrected distance visual acuity (UDVA) was 0.01 ± 0.10 LogMAR. All patients achieved an unaided distance acuity of 20/40 or better postoperatively. Binocularly, 100% saw 0.20 LogMAR or better at near without correction and 88.9% achieved this level for uncorrected intermediate visual acuity. No intraoperative complications were noted. Five patients complained of moderate haloes in the early postoperative period. CONCLUSION: The AcrySof IQ Panoptix IOL provides functional uncorrected visual acuity at distance, intermediate and near positions. Our results remain equivalent with existing trifocal IOL outcomes and provide surgeons with a further IOL alternative for the patient motivated to obtain true spectacle independence. Surgeons should consider individual reading and working requirements when counselling patients preoperatively to optimise postoperative patient satisfaction
Abnormal M1/M2 macrophage phenotype profiles in the small airway wall and lumen in smokers and chronic obstructive pulmonary disease (COPD)
© 2017 The Author(s). We explore potential dysregulation of macrophage phenotypes in COPD pathogenesis through integrated study of human small airway tissue, bronchoalveolar lavage (BAL) and an experimental murine model of COPD. We evaluated human airway tissue and BAL from healthy controls, normal lung function smokers (NLFS), and COPD subjects. Both small airways and BAL cells were immunohistochemically stained with anti-CD68 for total macrophages and with anti-CD163 for M2, and anti-iNOS for M1 macrophages. Multiplex ELISA measured BAL cytokines. Comparable cigarette smoke-induced experimental COPD mouse model was assessed for relevant mRNA profiles. We found an increase in pro-inflammatory M1s in the small airways of NLFS and COPD compared to controls with a reciprocal decrease in M2 macrophages, which remained unchanged among pathological groups. However, luminal macrophages showed a dominant M2 phenotype in both NLFS and COPD subjects. BAL cytokine skewed towards an M2 profile with increase in CCL22, IL-4, IL-13, and IL-10 in both NLFS and COPDs. The mouse-model of COPD showed similar increase in mRNA for M2 markers. Our finding suggests abnormal macrophage switching in both mucosal and luminal areas of COPD patients, that strongly associated with cytokine balance. There may be potential for beneficial therapeutic cytokine manipulation of macrophage phenotypes in COPD
Morphological Criteria for Comparing Effects of X-Rays and Neon Ions on Mouse Small Intestine
Several techniques have been used to assess changes in different parts of mouse small intestine three days after a single dose of either 16.5 Gy X-rays or 11 Gy neon beam. The doses were chosen to be approximately equivalent in terms of their effect on the number of microcolonies present.
In qualitative terms, villous damage was seen after both types of radiation exposure: collared crypts, similar to those seen in biopsies taken from patients suffering from coeliac disease, were conspicuous after neon irradiation.
In semi quantitative terms the doses used, although estimated from previous work to give biologically equivalent damage, produced a greater drop in microcolony numbers after X-irradiation, This makes all the more important the fact that significantly greater changes were seen after neon irradiation - a greater drop was seen in the number of villous profiles and the number of goblet cells per villus. There was also greater breakdown in the integrity of the villous basement membrane.
Different responses after the two types of irradiation are therefore seen in the cryptal and villous compartment. Progress is being made towards identifying and quantitating radiation induced changes in different populations of cells or tissues in the small intestine
Electron exchange model potential: Application to positronium-helium scattering
The formulation of a suitable nonlocal model potential for electron exchange
is presented, checked with electron-hydrogen and electron-helium scattering,
and applied to the study of elastic and inelastic scattering and ionization of
ortho positronium (Ps) by helium. The elastic scattering and the
excitations of Ps are investigated using a three-Ps-state close-coupling
approximation. The higher () excitations and ionization of Ps atom are
treated in the framework of Born approximation with present exchange.
Calculations are reported of phase shifts, and elastic, Ps-excitation, and
total cross sections. The present target elastic total cross section agrees
well with experimental results at thermal to medium energies.Comment: 16 latex pages, 7 postscript figure
Positronium scattering by atoms and molecules at low energies
The recent theoretical and experimental activities in positronium (Ps)
scattering by atoms and molecules are reviewed with special emphasis at low
energies. We critically compare the results of different groups theoretical
and experimental. The theoretical approaches considered include the -matrix
and close-coupling methods applied to Ps-H, Ps-He, and Ps-Li scattering, and a
coupled-channel approach with a nonlocal model-potential for Ps scattering by
H, He, H, Ne, Ar, Li, Na, K, Rb, Cs, and Ps and for pickoff quenching in
Ps-He scattering. Results for scattering lengths, partial, total and
differential cross sections as well as resonance and binding energies in
different systems are discussed.Comment: 6 revtex pages, 3 postscript figure
Change or control? Developing dialogues between research and public protection
This paper aims to scope out some of the implications of desistance research for the community management of high risk offenders. Acknowledging the limited empirical research exploring this interface, this paper outlines the evolving evidence base and what this tells us about the process of desistance and what supports it. The evidence as to whether 'high risk offenders' desist and what we know about this process is discussed prior to outlining the landscape of current and principal practice approaches which can be located in the community/public protection model. Potential dialogues between desistance research and public protection practices are discussed to explore ensuing implications and opportunities for practice
Reliability of retinal vessel calibre measurements using a retinal oximeter
Background: Summarised retinal vessel diameters are linked to systemic vascular pathology. Monochromatic images provide best contrast to measure vessel calibres. However, when obtaining images with a dual wavelength oximeter the red-free image can be extracted as the green channel information only which in turn will reduce the number of photographs taken at a given time. This will reduce patient exposure to the camera flash and could provide sufficient quality images to reliably measure vessel calibres. Methods: We obtained retinal images of one eye of 45 healthy participants. Central retinal arteriolar and central retinal venular equivalents (CRAE and CRVE, respectively) were measured using semi-automated software from two monochromatic images: one taken with a red-free filter and one extracted from the green channel of a dual wavelength oximetry image. Results: Participants were aged between 21 and 62 years, all were normotensive (SBP: 115 (12) mmHg; DBP: 72 (10) mmHg) and had normal intra-ocular pressures (12 (3) mmHg). Bland-Altman analysis revealed good agreement of CRAE and CRVE as obtained from both images (mean bias CRAE = 0.88; CRVE = 2.82). Conclusions: Summarised retinal vessel calibre measurements obtained from oximetry images are in good agreement to those obtained using red-free photographs
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