Classical test theory versus Rasch analysis for quality of life questionnaire reduction

BACKGROUND: Although health-related quality of life (HRQOL) instruments may offer satisfactory results, their length often limits the extent to which they are actually applied in clinical practice. Efforts to develop short questionnaires have largely focused on reducing existing instruments. The approaches most frequently employed for this purpose rely on statistical procedures that are considered exponents of Classical Test Theory (CTT). Despite the popularity of CTT, two major conceptual limitations have been pointed out: the lack of an explicit ordered continuum of items that represent a unidimensional construct, and the lack of additivity of rating scale data. In contrast to the CTT approach, the Rasch model provides an alternative scaling methodology that enables the examination of the hierarchical structure, unidimensionality and additivity of HRQOL measures. METHODS: In order to empirically compare CTT and Rasch Analysis (RA) results, this paper presents the parallel reduction of a 38-item questionnaire, the Nottingham Health Profile (NHP), through the analysis of the responses of a sample of 9,419 individuals. RESULTS: CTT resulted in 20 items (4 dimensions) whereas RA in 22 items (2 dimensions). Both instruments showed similar characteristics under CTT requirements: item-total correlation ranged 0.45–0.75 for NHP20 and 0.46–0.68 for NHP22, while reliability ranged 0.82–0.93 and 0.87–94 respectively. CONCLUSIONS: Despite the differences in content, NHP20 and NHP22 convergent scores also showed high degrees of association (0.78–0.95). Although the unidimensional view of health of the NHP20 and NHP22 composite scores was also confirmed by RA, NHP20 dimensions failed to meet the goodness-of fit criteria established by the Rasch model, precluding the interval-level of measurement of its scores

Effect of aclidinium bromide on exacerbations in patients with moderate to severe COPD: a pooled analysis of five Phase III, randomized, placebo-controlled studies

We investigated the effect of the long-acting muscarinic antagonist aclidinium bromide on chronic obstructive pulmonary disease (COPD) exacerbations by pooling data from five randomized, placebo-controlled,parallel-group Phase III studies of 3-6 months' duration. Data were pooled from the aclidinium 400 μg twice-daily (BID) and placebo arms (N = 2,521) and stratified by Global initiative for chronic Obstructive Lung Disease (GOLD) group (A, B, C and D). Results showed that fewer patients experienced 1 exacerbation with aclidinium (any severity: 12.5%; moderate to severe: 10.9%) compared with placebo (any severity: 15.7%; moderate to severe: 13.3%) and the odds of experiencing 1 exacerbation of any severity were reduced in patients receiving aclidinium (odds ratio = 0.78, p = 0.039). Furthermore, aclidinium reduced the rate of exacerbations compared with placebo (any severity: rate ratio = 0.79, p = 0.026; moderate to severe: 0.80, p = 0.044). The time to first exacerbation of any severity was delayed with aclidinium compared with placebo (hazard ratio = 0.79, p = 0.026) and there was a numerical delay in time to first moderate-to-severe exacerbation. Finally, the effects of aclidinium on exacerbations versus placebo were greater in patients in GOLD Groups B and D; however, it is of note that only 10.7% of patients were classified in Group A or C. In summary, the results indicate that aclidinium 400 μg BID reduces the frequency of COPD exacerbations compared with placebo and that these effects are greater in symptomatic patients

El yacimiento geotérmico del Serrablo

Debido a la importancia que está adquiriendo la producción de energías renovables en la sociedad actual, y en especial con motivo del creciente interés que dentro de éstas está despertando la geotermia, se ha decidido plantear este estudio sobre el funcionamiento de un sistema geotérmico en la zona del Serrablo. El objetivo de este estudio es caracterizar el yacimiento geotérmico del Serrablo con el fin de realizar una estimación del potencial geotérmico de la zona y desarrollar una hipótesis sobre su posible funcionamiento. El motivo principal de la elección de la zona de Serrablo es que se trata de una zona que ya despertó interés geotérmico durante la década de 1980, en la que aprovechando los datos de los sondeos realizados en la exploración de hidrocarburos en la zona, se consiguió localizar un acuífero con posibilidades geotermales por las avenidas de agua a alta temperatura (mayor de 150ºC) producidas durante la perforación de los sondeos en los niveles carbonatados del Daniense. La metodología aplicada, incluye la revisión bibliográfica de los informes referentes a los sondeos y al yacimiento geotérmico, la reconstrucción de las columnas de sondeo y la realización de un panel de correlación que permita determinar características cómo la extensión y potencia del acuífero, para realizar una modelización de carácter conservativo del sistema. Además, a partir de estudios paleogegráficos regionales se argumenta la hipótesis de la existencia de un paleokarst que afecta a los materiales que constituyen el reservorio, y a través de comparaciones con otros sistemas geotérmicos europeos, nos permite realizar una estimación no conservativa del funcionamiento del sistema. Los datos obtenidos al final del estudio, muestran que según la hipótesis conservativa, la capacidad de producción de la central sería de 5,16 MWel, dato que entra dentro de lo esperable según las características del acuífero, y con un rango aceptable para la producción eléctrica

Effect of a spacer on total systemic and lung bioavailability in healthy volunteers and in vitro performance of the Symbicort\uae (budesonide/formoterol) pressurized metered dose inhaler

Introduction: Many patients with chronic obstructive pulmonary disease or asthma experience difficulties in coordinating inhalation with pressurized metered-dose inhaler (pMDI) actuation. The use of a spacer device can improve drug delivery in these patients. The aim of this study was to establish the relative bioavailability of single doses of Symbicort\uae (budesonide/formoterol) pMDI 160/4.5 μg/actuation (2 actuations) used with and without a spacer device. In addition, an in vitro study was conducted to characterize performance of the inhaler when used in conjunction with a spacer device. Methods: A Phase I, randomized, open-label, single-dose, single-center, crossover study in 50 healthy volunteers (NCT02934607) assessed the relative bioavailability of single-dose Symbicort\uae pMDI 160/4.5 μg/actuation (2 actuations) with and without a spacer (AeroChamber Plus\uae Flow-Vu\uae). Inhaled doses were administered without or with activated charcoal (taken orally) to estimate total systemic exposure and exposure through the lung, respectively. The in vitro study characterized the effect of the spacer with respect to delivered dose, fine particle dose, and dose during simulated breathing of budesonide and formoterol. Results: In terms of total systemic exposure, use of the spacer increased the relative bioavailability determined by AUC(0-last) and Cmax by 68% (spacer:no spacer treatment ratio, 167.9%; 90% CI, 144.1 to 195.6) and 99% (ratio, 198.7%; 90% CI, 164.4 to 240.2) for budesonide, and 77% (ratio, 176.6%; 90% CI, 145.1 to 215.0) and 124% (ratio, 223.6%; 90% CI, 189.9 to 263.3) for formoterol, respectively, compared with pMDI alone. Similarly, the lung exposure of budesonide and formoterol increased (AUC(0-last) and Cmax by 146% [ratio, 246.0%; 90% CI, 200.7 to 301.6] and 127% [ratio, 226.5%; 90% CI, 186.4 to 275.4] for budesonide, and 173% [ratio, 272.8%; 90% CI, 202.5 to 367.4] and 136% [ratio, 236.2%; 90% CI, 192.6 to 289.6] for formoterol, respectively) when the pMDI was administered through the spacer. When assessed by AUC(0-last) quartile without spacer, subjects in the lowest exposure quartile (indicating poor inhalation technique) with Symbicort\uae pMDI 160/4.5 μg/actuation (2 actuations) had markedly increased total systemic and lung exposure when the same dose was administered with the spacer. In contrast, for subjects in the highest exposure quartile with pMDI alone, total systemic and lung exposure of formoterol and budesonide was similar with and without the spacer. In the in vitro study, the fine particle dose (<5 μm) of both budesonide and formoterol from the spacer at delay time (i.e. pause period after actuation) = 0 s (instantaneous) after actuation was similar to the fine particle dose when not using the spacer. The delivered doses of budesonide and formoterol from the spacer were both lower compared with the doses administered without the spacer. There was also a decrease in delivered dose with increasing delay time. Conclusions: The clinical study demonstrated that in subjects with poor inhalation technique the use of the AeroChamber Plus\uae Flow-Vu\uae spacer increased the bioavailability of Symbicort\uae pMDI to a level observed in subjects with good inhalation technique without a spacer. The findings from the in vitro study support the fine particle dose characteristics of Symbicort\uae pMDI with the AeroChamber Plus\uae Flow-Vu\uae spacer

Long-Lasting Efficacy of Radio Electric Asymmetric Conveyer Neuromodulation Treatment on Functional Dysmetria, an Adaptive Motor Behavior

BackgroundFluctuating asymmetry (FA) is widely defined as the deviation from perfect bilateral symmetry and is considered an epigenetic measure of environmental stress. Rinaldi and Fontani hypothesized that the FA morpho-functional changes originate from an adaptive motor behavior determined by functional alterations in the cerebellum and neural circuits, not caused by a lesion, but induced by environmental stress. They called this phenomenon functional dysmetria (FD). On this premise, they developed the radio electric asymmetric conveyer (REAC) technology, a neuromodulation technology aimed at optimizing the best neuro-psycho-motor strategies in relation to environmental interaction.AimsPrevious studies showed that specific REAC neuro postural optimization (NPO) treatment can induce stable FD recovery. This study aimed to verify the duration of the NPO effect in inducing the stable FD recovery over timeMaterials and methodsData were retrospectively collected from a population of 29,794 subjects who underwent a specific semiological FD assessment and received the NPO treatment, regardless of the pathology referred.ResultsThe analysis of the data collected by the various participants in the study led us to ascertain the disappearance of FD in 100% of the cases treated, with a stability of the result detected up to 18 years after the single administration of the REAC NPO treatment.ConclusionsThe REAC NPO neurobiological modulation treatment consisting of a single administration surprisingly maintains a very long efficacy in the correction of FD. This effect can be explained as the long-lasting capacity of the NPO treatment to induce greater functional efficiency of the brain dynamics as proven in previous studies

Gender diferences in the association between disability and mortality in the elderly

Aquesta tesi avalua l'existència de diferencies per gènere en la relació entre discapacitat i mortalitat, i aspectes metodològics en l'anàlisi de supervivènciad'estudis de gent gran. Es van utilitzar les dades provinents d'una cohort de 1.315 subjectes amb edats superiors o iguals a 65 anys que van ser seguits durant un periode de 8 anys. La discapacitat es va mesurar mitjançant la capacitat que declarava l'individu per dur a terme activitats de la vida diària bàsiques. La discapacitat va evolucionar al llarg del temps empitjorant amb l'edat, però una proporció no menyspreable va ser capaç de recuperar-se. Es van observar diferències per gènere en l'evolució de la discapacitat: les dones tenien més dificultats en recuperar la seva capacitat funcional un cop esdevenien discapacitades. La força de l'associació entre la discapacitat i la mortalitat disminuia a edats avançades. Es van trobar diferencies per sexe: les dones depenents mostraven un risc de morir més alt que el homes depenents. Polítiques de salut dirigides a dones discapacitades haurien de ser implementades degut a la proporció més elevada de dones discapacitades, la probabilitat menor que tenen de recuperar la capacitat funcional, i el risc de morir més elevat que presenten comparat amb homes dicapacitats.This thesis evaluates the existence of gender differences in the relationship between disability and mortality, as well as methodological aspects of the survival analysis for elderly studies. Data from a cohort of 1,315 subjects aged 65 years and older followed-up 8 years was used. Disability was assessed by self-reported difficulty to perform basic activities of daily living. Disability evolved over time worsening with age, but a non-negligible proportion was able to recover. There were gender differences in the evolution of disability: women were less able to regain functional capacity once they become disabled. The strength of the association between disability and mortality decreased in the older ages. But differences by gender were found: dependent elderly women showed a higher risk of dying compared to dependent men. Health policies focusing on disabled women should be implemented, due to the higher proportion of disabled women, the lower probability of regaining functional capacity, and their higher risk of dying compared to disabled men

Petjades d'una estadística: un tomb per la vida professional. Curs Kolmogórov (2021-2022)

En el marc de la celebració del 8M, Dia Internacional de la Dona, l'FME convida Rosa Lamarca, llicenciada en Ciències i Tècniques Estadístiques per la UPC amb més de 20 anys d'experiència en la indústria farmacèutica, que ens farà una presentació del seu bagatge acadèmic i professional amb perspectiva de gènere. Al final s’obrirà un espai de debat i d'intercanvi d'opinions, buscant la participació i la complicitat dels assistents