Jason Landon

Validation of the WHOQOL-BREF quality of life questionnaire for general use in New Zealand: confirmatory factor analysis and Rasch analysis

PurposeThe present study validated the abbreviated version of the World Health Organization Quality of Life (WHOQOL-BREF) questionnaire for general use in New Zealand.MethodsA random postal sample from the national electoral roll was used, and 808 questionnaires were returned. Psychometric properties of the instrument were assessed, including tests of the four-domain factor structure using confirmatory factor analysis and Rasch analysis.ResultsGoodness-of-fit from the confirmatory factor analysis were good, and the overall conclusion of the Rasch analysis supported the confirmatory factor analysis (CFA) findings after dealing with problems of threshold ordering, local dependency, and differential item functioning (DIF).ConclusionsThe WHOQOL-BREF is valid for general use in New Zealand. In the future work, the WHOQOL-BREF domain scores should either be analyzed using non-parametric statistics or data should be fitted to the Rasch model to derive interval person estimates.

Prenatally undernourished rats show increased preference for wheel running v. lever pressing for food in a choice task.

Maternal nutrition during pregnancy has a significant influence in establishing patterns of metabolism and postnatal behaviours in offspring, and therefore shapes their risk of developing disorders in later life. Although it is well established that a mismatch between food consumption and energy expenditure leads to obesity and metabolic dysregulation, little research has investigated the biological origin of such behaviour. We conducted the present experiments to investigate effects of early-life nutrition on preference between wheel running and lever pressing for food during adult life. To address this issue we employed a well-established experimental approach in the rat which has shown that offspring of mothers undernourished during pregnancy develop obesity and metabolic disorders when kept under standard laboratory conditions. Using this experimental approach, two studies were conducted where offspring of ad libitum-fed dams and dams undernourished throughout pregnancy were given the choice between wheel running and pressing a response lever for food. Across subsequent conditions, the rate at which the response lever provided food was varied from 0.22 to 6.0 (study 1) and 0.19 to 3.0 (study 2) pellets per min. Compared with the control group, offspring from dams undernourished during pregnancy showed a consistently greater preference for running over lever pressing for food throughout both experiments of the study. The results of the present study provide experimental evidence that a mothers nutrition during pregnancy can result in a long-term shift in her offsprings lifestyle choices that are relevant to obesity prevention. Such a shift, if endorsed, will have substantial and wide-ranging health consequences throughout the lifespan.

Global undernutrition during gestation influences learning during adult life

Intrauterine growth restriction can lead to significant long-term health consequences such as metabolic and cardiovascular disorders, but less is known about its effects on choice and behavioral adaptation in later life. Virgin Wistar rats were time mated and randomly assigned to receive either ad-libitum access to chow or 30% of that level of nutrition during pregnancy to generate growth-restricted offspring. At 60 days of age, 6 female offspring from each group were trained on concurrent variable-interval schedules. Sessions consisted of seven randomly arranged concurrent-schedule components, each with a different reinforcer ratio that varied from 27∶1 to 1∶27, and each component lasting for 10 reinforcer deliveries. Behavioral change across reinforcers in components, measured by sensitivity to reinforcement, was consistently lower for offspring of undernourished mothers, showing that their behavior was less adaptable to environmental change. These results provide direct experimental evidence for a link between prenatal environmental conditions and reduced behavioral adaptability—learning—in later life.

Hearing every footstep: Noise sensitivity in individuals following traumatic brain injury

Noise sensitivity is an important and under-researched symptom that can result from traumatic brain injury (TBI). Interpretative phenomenological analysis (IPA) was used to analyse the experiences of noise sensitivity of six individuals with TBI. The results revealed four major themes through which participants described a process of having to find information for themselves to understand what they were experiencing and their changed relationship with sounds. The participants also described feeling overwhelmed as they struggled to cope with the changes to their lives and being able to plan and take some control over their lives. The findings are of importance for both health professionals involved in rehabilitation and individuals recovering from TBI.

When it’s quiet, it’s nice: Noise sensitivity in schizophrenia

ABSTRACT The clinical literature has not given sufficient attention to the phenomenology of noise sensitivity (NS) as experienced by those with schizophrenia, focusing instead on electrophysiological measurements. This study sought to explore and document the experiences of NS in people with schizophrenia. Seven participants with a diagnosis of schizophrenia and reporting to experience noise sensitivity were recruited. Data were collected through participant-led semi-structured interviews, and a data-driven thematic analysis used to summarize patterns of participants’ experiences. Five themes were identified, exemplified by direct quotes: (1) I didn’t even know it was mentionable, (2) Normal people I guess must just shut them (sounds) off, (3) It’s just very stressful, (4) that’s when insanity creeps in, and (5) when it’s quiet, it’s nice. Awareness of noise sensitivity is important for those affected, and thus those working with them. Validating and sharing experiences such as those documented here is an important early step as NS has effects on many aspects of peoples’ lives. Efforts to develop appropriate clinical interventions and support effective coping strategies should be encouraged.

Human choice behaviour in a frequently changing environment.

The present experiment provided a replication in humans of an experimental procedure that has been used frequently with nonhumans to investigate choice behaviour in a changing environment. Six volunteers played a computer game, which required tracking of a moving balloon on two simultaneously available response panels for monetary reinforcers. Each of the 15 sessions randomly arranged the following concurrent variable-interval reinforcement schedules, which were in effect until six reinforcers had been obtained: 27:1, 9:1, 3:1, 1:1, 1:3, 1:9, and 1:27. Although many aspects of human performance appeared to be qualitatively similar to that of nonhumans on this procedure, such as the rapid preference shifts towards the within-session reinforcer ratios and the presence of local effects of reinforcers, values of sensitivity to reinforcement were very variable in the present study, as commonly reported in human choice studies. Future variations and refinements of the experimental methods are needed to explore how this variability may be reduced.

Developmental Origins of Health and Disease: The developmental environment: influences on subsequent cognitive function and behaviour

The concept of the developmental origins of adult disease was initially based on epidemiological observations relating evidence of a constrained fetal environment to a greater risk of metabolic and cardiovascular disorders in adult life. It was later recognised that those at greatest risk also have an increased propensity to developing obesity in childhood and during adult life (Barker and Osmond 1988, Hales and Barker 1992, Gluckman and Hanson 2004). The interest in the later effects of early environmental events has since been generalised to include possible prenatal effects on offspring behaviour and cognition. In this chapter, we review the existing human and animal literature on the early-life influences on offspring cognitive function and behaviour.

Documenting and Understanding Parent’s Intervention Choices for Their Child with Autism Spectrum Disorder

Understanding why parents choose some interventions but not others for their child with autism is important for a number of reasons. Estimating the proportion of evidence-based interventions engaged, identifying the agencies influencing parental decisions, and elucidating the barriers or reasons leading to intervention rejection or discontinuation can result in better service provision. New Zealand parents (n = 570) of a child with autism reported what interventions were being engaged, and why some interventions were engaged but not others. Funding was a major determinant of intervention engagement, while medical professionals exerted the most influence. Sources of support were not related to intervention engagement, but parental perceptions of their child’s symptom severity were. Finally, non-engagement does not necessarily reflect parental opposition to an intervention, but rather the existence of barriers.

Symptom severity, caregiver stress and intervention helpfulness assessed using ratings from parents caring for a child with autism:

This exploratory study assessed the relationships between autism spectrum disorder symptoms, caregiver stress and intervention helpfulness, using parent (n = 182) ratings. Advocacy and intervention-related tasks were rated more stressful than support tasks (e.g. toileting, mealtimes), indicating that advocacy is emerging as a major caregiver task for parents. Deficits in prosocial behaviours were perceived to have the highest impact on the child’s function. No difference was found between mean helpfulness ratings across the six representative interventions taken from the New Zealand context. Differences in care-related task stress across intervention choices were better explained by differences in symptom severity, suggesting that impairment drives intervention choice. Limited evidence was uncovered suggesting that intervention helpfulness moderates the relationship between core autism spectrum disorder symptoms and parent stress.

Ordinal-To-Interval Scale Conversion Tables and National Items for the New Zealand Version of the WHOQOL-BREF.

The World Health Organisation Quality of Life (WHOQOL) questionnaires are widely used around the world and can claim strong cross-cultural validity due to their development in collaboration with international field centres. To enhance conceptual equivalence of quality of life across cultures, optional national items are often developed for use alongside the core instrument. The present study outlines the development of national items for the New Zealand WHOQOL-BREF. Focus groups with members of the community as well as health experts discussed what constitutes quality of life in their opinion. Based on themes extracted of aspects not contained in the existing WHOQOL instrument, 46 candidate items were generated and subsequently rated for their importance by a random sample of 585 individuals from the general population. Applying importance criteria reduced these items to 24, which were then sent to another large random sample (n = 808) to be rated alongside the existing WHOQOL-BREF. A final set of five items met the criteria for national items. Confirmatory factor analysis identified four national items as belonging to the psychological domain of quality of life, and one item to the social domain. Rasch analysis validated these results and generated ordinal-to-interval conversion algorithms to allow use of parametric statistics for domain scores with and without national items.