Proposta d'un model d'equacions estructurals per a l'estudi de l'efecte de l'activitat física en la qualitat de vida de les persones amb discapacitat intel·lectual

Les persones amb discapacitat intel·lectual no practiquen els nivells suficients d’activitat física per que aquesta impliqui una millora de la seva qualitat de vida. Estudiar la relació entre ambdós constructes és clau per afavorir-la en cas de que no es doni. L’objectiu d’aquesta tesi és, per tant, identificar quin impacte produeix la pràctica d’activitat física en la qualitat de vida de persones amb discapacitat intel·lectual avaluant cadascuna de les vuit dimensions que la defineixen segons el criteri internacionalment acceptat. Per a fer-ho s’han validat dos instruments per avaluar, per una banda, la qualitat de vida en termes de resultats personals i, per l’altra, les necessitats i estratègies de suport en l’àmbit de l’activitat física. El primer instrument l’hem obtingut de la traducció i adaptació de la Personal Outcomes Scale i el segon s’ha elaborat ex-novo degut que en la bibliografia consultada no disposàvem de cap eina que s’ajustés a la nostra finalitat. La mostra ha estat formada per persones adultes amb discapacitat intel·lectual (n=529), els seus professionals de referència (n=522) i un membre de la família (n= 462). A tots ells se’ls va administrar els dos instruments per entrevistadors prèviament formats. A partir de les dades obtingudes en cada instruments s’han examinat tant la fiabilitat i la validesa; i posteriorment s’han estimat els paràmetres estructurals que ens han permès confirmar que l’activitat física té un impacte significatiu en la millora de la qualitat de vida de les persones amb discapacitat intel·lectual. Cadascuna de les fases realitzades i els resultats corresponents obtinguts han donat lloc als quatre articles que es presenten en aquesta tesi.Las personas con discapacidad intelectual no practican suficiente actividad física para que ello represente una mejora de su calidad de vida. Estudiar la relación entre ambos constructos es clave para favorecerla en caso de que no se dé. El objetivo de esta tesis es, por tanto, identificar qué impacto produce la práctica de actividad física en la calidad de vida de personas con discapacidad intelectual evaluando cada una de las ocho dimensiones que la definen según el criterio internacionalmente aceptado. Para ello se validaron dos instrumentos para evaluar, por una parte, la calidad de vida en términos de resultados personales y, por otra, las necesidades y estrategias de ayuda en el ámbito de la actividad física. El primer instrumento se obtuvo a partir de la traducción y adaptación de la Personal Outcome Scale y el segundo se elaboró ex-novo debido que en la bibliografía consultada no se dispuso de ninguna prueba que se ajustara a nuestra finalidad. La muestra estuvo compuesta por personas adultas con discapacidad intelectual (n=529), sus profesionales de referencia (n=522) y un miembro de la familia (n=462). A todos ellos se les administró los dos instrumentos mediante entrevistadores previamente formados. A partir de los datos obtenidos en cada instrumento se examinaron tanto la fiabilidad como la validez y, posteriormente se estimaron los parámetros estructurales que nos ha permitido confirmar que la actividad física tiene un impacto significativo en la mejora de la calidad de vida en las personas con discapacidad intelectual. Cada una de las fases realizadas y resultados correspondientes ha dado lugar a los cuatro trabajos que se presentan en esta tesis.People with intellectual disabilities do not get enough physical activity so that it represents an improvement in their quality of life. To study the relationship between both constructs is important to favor it if you do not give. The aim of this thesis is therefore to identify what impact does the practice of physical activity on the quality of life of people with intellectual disabilities evaluating each of the eight dimensions that define it according to internationally accepted criteria. For this, two questionnaires for assessing, on the one hand, the quality of life in terms of personal outcomes and, on the other, needs and assistance strategies in the area of physical activity were validated. The first instrument was obtained from the translation and adaptation of the Personal Outcome Scale and the second was drawn up ex-novo because in the literature were not available no evidence that suited our purpose. The sample consisted of adults with intellectual disability (n = 529), their professional reference (n = 522) and a member of the family (n = 462). All of them were given the two instruments by interviewers previously trained. From the data obtained in each instrument both reliability and validity were examined, then the structural parameters estimation enabled us to confirm that physical activity has a significant impact on improving the quality of life in people with estimated intellectual disability. Each of the phases made and corresponding results has led to the four works presented in this thesis

Psychometric properties of the Spanish version of the Personal Outcomes Scale

Personal outcomes-related quality of life provides information about the impact of individualized supports and services that are provided to people with intellectual disability. The Personal Outcomes Scale (POS) is a valid and reliable instrument that measures these outcomes using two parts, self-report and report by others. Based on the POS, the aim of this study is to provide a new psychometric study of the instrument that allows the evaluation of the three principal informers involved in the enhancement of individual's quality of life: individual with intellectual disability, professional and family member. This approach overcomes the limitations of the POS. For the self-report were involved 529 people with intellectual disability. A professional (N=522) and a family member (N=462) separately participated for the report by others versions to assess personal outcomes for each participant. The reliability study provides appropriate values for the first and second order factors with α values being higher than .82. The construct validity analysis provides an adjustment of the theoretical model, particularly regarding the assessments from professionals. Results show this instrument is adequate to evaluate personal outcomes and giving the guidelines for making policy and practice decisions

Eliminate the effect of severity of the Personal Outcomes Scale: Linear regression in persons with intellectual disability

Background: The Personal Outcomes Scale (POS) is used to assess quality of life (QoL) in people with intellectual disability (ID) but the results are infl uenced by the severity of the disability. To address this issue, we present the standardization of the Spanish adaptation of the POS. One of the limitations of the Classical Test Theory is the differential effect in some items due to the effect of an external variable. For this reason, we propose the use of multiple linear regressions. Method: We used a sample of 529 people with ID, along with 522 professionals and 462 parents who were administered the POS in order to carry out an in-depth psychometric study. For the analysis, we used the correction strategy by multiple linear regressions to generate centiles corrected for the severity effect of ID. Results: Following this technique, the results show the centiles from the raw POS score corrected for the effect of the severity of ID. Conclusions: This standardization technique is a feasible option to provide a QoL scale without biased results due to the severity of ID

Using fMRI to assess brain activity in people with Down Syndrome: A systematic review

Background: In the last few years, many investigations have focused on brain activity in general and in populations with different pathologies using non-invasive techniques such as electroencefalography (EEG), positron emission tomography (PET), functional magnetic resonance imaging (fMRI) and magnetic resonance imaging (MRI). However, the use of non-invasive techniques to detect brain signals to evaluate the cognitive activity of people with Down syndrome (DS) has not been sufficiently addressed. The objective of this study is to describe the state-of-the-art in fMRI techniques for recording brain signals in people with DS. Method: A systematic review was performed based on PRISMA recommendations; only nine papers on this topic have been published. Three independent researchers selected all relevant information from each paper. Analyses of information concordance showed a high value of agreement between researchers. Results: Although few relevant works have been published, the use of fMRI in people with DS is becoming an appropriate option to study brain function in this population. Of the nine identified papers, five used task designs, and four used resting-state paradigms. Conclusion: Thus, we emphasize the need to incorporate rigorous cognitive activity procedures in evaluations of the DS population. We suggest several factors (such as head correction movements and paired sample techniques) that must be considered when designing an fMRI study with a task or a resting-state paradigm in a DS population

Impact of the intellectual disability severity in the Spanish Personal Outcomes Scale

Background The interest in measuring quality of life (QoL) in persons with intellectual disability (ID) has brought about a number of QoL measurements for this population. These measurements need to address two issues that have contributed to enhancing the current instruments. First, the necessity to develop measures with adequate psychometric properties, which has been discussed in recent studies, and second, the agreement between experts in analysing objective and subjective perspectives, as well as the use of self‐report to include the participation of the person with ID. The question that we set out to investigate in this paper is whether the measurements function properly for the person with ID, independent of their level of severity. We used the Spanish version of the Personal Outcomes Scale, as it is a psychometrically sound instrument and includes three sources of information (the person with ID, a professional and a family member). Method The sample was composed of 529 persons with ID (296 men, representing 55.95% of the total sample, and 233 women, with M age = 35.03, SD = 10.82) from several regions of Spain, along with their professional of reference and a family member. The severity variable was estimated for each item based on estimations of differential item functioning. Results The results showed that several items were undervalued by the assessments if the severity of the ID was greater. Mainly, this difference was observed in the assessments by professionals and in the dimensions of rights, personal development and self‐determination. Conclusions This paper focuses on the uses and interpretations of the results of the QoL measurements in the Personal Outcomes Scale. The results indicate that, in our sample, when people with high levels of ID are assessed, the functioning of some items are affected by the severity of this disability. For correct use, these items must be interpreted on the basis of the results obtained. Additionally, it is necessary to thoroughly review the QoL indicators for persons with severe or profound ID

Item response theory analysis applied to the Spanish version of the Personal Outcomes Scale

BackgroundThe study of measurements of quality of life (QoL) is one of the great challenges of modern psychology and psychometric approaches. This issue has greater importance when examining QoL in populations that were historically treated on the basis of their deficiency, and recently, the focus has shifted to what each person values and desires in their life, as in cases of people with intellectual disability (ID). Many studies of QoL scales applied in this area have attempted to improve the validity and reliability of their components by incorporating various sources of information to achieve consistency in the data obtained. The adaptation of the Personal Outcomes Scale (POS) in Spanish has shown excellent psychometric attributes, and its administration has three sources of information: self-assessment, practitioner and family. The study of possible congruence or incongruence of observed distributions of each item between sources is therefore essential to ensure a correct interpretation of the measure. The aim of this paper was to analyse the observed distribution of items and dimensions from the three Spanish POS information sources cited earlier, using the item response theory.MethodWe studied a sample of 529 people with ID and their respective practitioners and family member, and in each case, we analysed items and factors using Samejima's model of polytomic ordinal scales.ResultsThe results indicated an important number of items with differential effects regarding sources, and in some cases, they indicated significant differences in the distribution of items, factors and sources of information.ConclusionsAs a result of this analysis, we must affirm that the administration of the POS, considering three sources of information, was adequate overall, but a correct interpretation of the results requires that it obtain much more information to consider, as well as some specific items in specific dimensions. The overall ratings, if these comments are considered, could result in bias

Relationship between Quality of Life and the Complexity of Default Mode Network in Resting State Functional Magnetic Resonance Image in Down Syndrome

Abstract: Background: The study of the Default Mode Network (DMN) has been shown to be sensitive for the recognition of connectivity patterns between the brain areas involved in this network. It has been hypothesized that the connectivity patterns in this network are related to di erent cognitive states. Purpose: In this study, we explored the relationship that can be estimated between these functional connectivity patterns of the DMN with the Quality-of-Life levels in people with Down syndrome, since no relevant data has been provided for this population. Methods: 22 young people with Down syndrome were evaluated; they were given a large evaluation battery that included the Spanish adaptation of the Personal Outcome Scale (POS). Likewise, fMRI sequences were obtained on a 3T resonator. For each subject, the DMN functional connectivity network was studied by estimating the indicators of complexity networks. The variability obtained in the Down syndrome group was studied by taking into account the Quality-of-Life distribution. Results: There is a negative correlation between the complexity of the connectivity networks and the Quality-of-Life values. Conclusions: The results are interpreted as evidence that, even at rest, connectivity levels are detected as already shown in the community population and that less intense connectivity levels correlate with higher levels of Quality of Life in people with Down syndrome

Structural Equation Models to estimate Dynamic Effective Connectivity Networks in Resting fMRI. A comparison between individuals with Down syndrome and controls

Emerging evidence suggests that an effective or functional connectivity network does not use a static process over time but incorporates dynamic connectivity that shows changes in neuronal activity patterns. Using structural equation models (SEMs), we estimated a dynamic component of the effective network through the effects (recursive and nonrecursive) between regions of interest (ROIs), taking into account the lag 1 effect. The aim of the paper was to find the best structural equation model (SEM) to represent dynamic effective connectivity in people with Down syndrome (DS) in comparison with healthy controls. Twenty-two people with DS were registered in a functional magnetic resonance imaging (fMRI) resting-state paradigm for a period of six minutes. In addition, 22 controls, matched by age and sex, were analyzed with the same statistical approach. In both groups, we found the best global model, which included 6 ROIs within the default mode network (DMN). Connectivity patterns appeared to be different in both groups, and networks in people with DS showed more complexity and had more significant effects than networks in control participants. However, both groups had synchronous and dynamic effects associated with ROIs 3 and 4 related to the upper parietal areas in both brain hemispheres as axes of association and functional integration. It is evident that the correct classification of these groups, especially in cognitive competence, is a good initial step to propose a biomarker in network complexity studies

Altered spontaneous brain activity in Down Syndrome and its relation with cognitive outcome

Although Down syndrome (DS) is the most common genetic cause of neurodevelopmental delay, few neuroimaging studies have explored this population. This investigation aimed to study whole-brain resting-state spontaneous brain activity using fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo) strategies to find differences in spontaneous brain activity among young people with DS and controls and to correlate these results with cognitive outcomes. The sample comprised 18 persons with DS (age mean = 28.67, standard deviation = 4.18) and 18 controls (age mean = 28.56, standard deviation = 4.26). fALFF and ReHo analyses were performed, and the results were correlated with other cognitive variables also collected (KBIT-2 and verbal fluency test). Increased activity was found in DS using fALFF in areas involving the frontal and temporal lobes and left cerebellum anterior lobe. Decreased activity in DS was found in the left parietal and occipital lobe, the left limbic lobe and the left cerebellum posterior lobe. ReHo analysis showed increased activity in certain DS areas of the left frontal lobe and left rectus, as well as the inferior temporal lobe. The areas with decreased activity in the DS participants were regions of the frontal lobe and the right limbic lobe. Altered fALFF and ReHo were found in the DS population, and this alteration could predict the cognitive abilities of the participants. To our knowledge, this is the first study to explore regional spontaneous brain activity in a population with DS. Moreover, this study suggests the possibility of using fALFF and ReHo as biomarkers of cognitive function, which is highly important given the difficulties in cognitively evaluating this population to assess dementia. More research is needed, however, to demonstrate its utility

Abnormal degree centrality and functional connectivity in Down syndrome: A resting-state fMRI study

Background/Objective: Neuroimaging studies have shown brain abnormalities in Down syndrome (DS) but have not clarified the underlying mechanisms of dysfunction. Here, we investigated the degree centrality (DC) abnormalities found in the DS group compared with the control group, and we conducted seed-based functional connectivity (FC) with the significant clusters found in DC. Moreover, we used the significant clusters of DC and the seed-based FC to elucidate differences between brain networks in DS compared with controls. Method: The sample comprised 18 persons with DS (M = 28.67, SD = 4.18) and 18 controls (M = 28.56, SD = 4.26). Both samples underwent resting-state functional magnetic resonance imaging. Results: DC analysis showed increased DC in the DS in temporal and right frontal lobe, as well as in the left caudate and rectus and decreased DC in the DS in regions of the left frontal lobe. Regarding seed-based FC, DS showed increased and decreased FC. Significant differences were also found between networks using Yeo parcellations, showing both hyperconnectivity and hypoconnectivity between and within networks. Conclusions: DC, seed-based FC and brain networks seem altered in DS, finding hypo- and hyperconnectivity depending on the areas. Network analysis revealed between- and within-network differences, and these abnormalities shown in DS could be related to the characteristics of the population