On the validity of measuring change over time in routine clinical assessment: a close examination of item-level response shifts in psychosomatic inpatients

Objective: Significant life events such as severe health status changes or intensive medical treatment often trigger response shifts in individuals that may hamper the comparison of measurements over time. Drawing from the Oort model, this study aims at detecting response shift at the item level in psychosomatic inpatients and evaluating its impact on the validity of comparing repeated measurements. Study design and setting: Complete pretest and posttest data were available from 1188 patients who had filled out the ICD-10 Symptom Rating (ISR) scale at admission and discharge, on average 24 days after intake. Reconceptualization, reprioritization, and recalibration response shifts were explored applying tests of measurement invariance. In the item-level approach, all model parameters were constrained to be equal between pretest and posttest. If non-invariance was detected, these were linked to the different types of response shift. Results: When constraining across-occasion model parameters, model fit worsened as indicated by a significant Satorra–Bentler Chi-square difference test suggesting potential presence of response shifts. A close examination revealed presence of two types of response shift, i.e., (non)uniform recalibration and both higher- and lower-level reconceptualization response shifts leading to four model adjustments. Conclusions: Our analyses suggest that psychosomatic inpatients experienced some response shifts during their hospital stay. According to the hierarchy of measurement invariance, however, only one of the detected non-invariances is critical for unbiased mean comparisons over time, which did not have a substantial impact on estimating change. Hence, the use of the ISR can be recommended for outcomes assessment in clinical routine, as change score estimates do not seem hampered by response shift effects.

Using repeatability to study physiological and behavioural traits: ignore time-related change at your peril

© 2015 The Association for the Study of Animal Behaviour. Broad sense repeatability, which refers to the extent to which individual differences in trait scores are maintained over time, is of increasing interest to researchers studying behavioural or physiological traits. Broad sense repeatability is most often inferred from the statistic R (the intraclass correlation, or narrow sense repeatability). However, R ignores change over time, despite the inherent longitudinal nature of the data (repeated measures over time). Here, we begin by showing that most studies ignore time-related change when estimating broad sense repeatability, and estimate R with low statistical power. Given this problem, we (1) outline how and why ignoring time-related change in scores (that occurs for whatever reason) can seriously affect estimates of the broad sense repeatability of behavioural or physiological traits, (2) discuss conditions in which various indices of R can or cannot provide reliable estimates of broad sense repeatability, and (3) provide suggestions for experimental designs for future studies. Finally, given that we already have abundant evidence that many labile traits are 'repeatable' in that broad sense (i.e. R>. 0), we suggest a shift in focus towards obtaining robust estimates of the repeatability of behavioural and physiological traits. Given how labile these traits are, this will require greater experimental (and/or statistical) control and larger sample sizes in order to detect and quantify change over time (if present).

Beliefs about the causes of weight change in the Australian population

OBJECTIVE: To describe self-reported weight change and beliefs about the causes of weight change and to examine whether these vary by sex and weight status.
DESIGN: This cross-sectional population study examined data from the 1995 Australian National Health and Nutrition Surveys.
SUBJECTS: A total of 10 624 randomly-selected adults provided data.
MEASURES: Objectively measured height and weight, perceptions of current weight status, self-reported weight change over the past year, and reasons for weight change.
RESULTS: Thirty-five percent of participants reported a weight gain in the last 12 months, with females, and those already overweight more likely to report a recent increase in weight. Approximately one in five participants reported a recent weight loss. Those who had recently gained weight were more likely to perceive themselves as overweight regardless of actual weight status. Commonly reported reasons for weight gain included a change in physical activity level (52% males and 35% females) and a change in the amount of food/drink consumed (30% males, 27% females). Similar reasons were given for weight loss.
CONCLUSIONS: Findings of widespread reported weight gain, particularly among those already overweight, suggest Australia's obesity epidemic may be worsening. Strategies are urgently required to better inform individuals about the factors impacting on their weight in order to prevent further weight gain.

Socioeconomic status and weight change in adults: a review

In developed countries, obesity is inversely associated with socioeconomic status (SES) among women, and less consistently among men; whereas, in developing countries, the association is direct. However, the relationship of SES to weight change over time is unknown. This relationship was the focus of the present literature review. It was hypothesized that, compared with persons of higher SES, persons of low SES would show greater weight gain or risk of weight gain over time. A search of electronic databases identified 34 relevant articles from developed countries reporting on studies that assessed the relationship of various measures of SES with weight change over time in adults (there were too few papers from developing countries (n=1) to include). Results of the methodologically strongest studies (those which obtained objectively measured adiposity data and used a follow-up period of 4 years or more) showed that, among non-black samples, there were relatively consistent inverse associations between occupation and weight gain for men and women. When SES was assessed using education, evidence was slightly less consistent, but still provided some support for the hypothesized relationship. However, when income was used as the indicator of SES, findings were inconsistent, although there were fewer studies available. There was little support for a relationship between SES and weight gain for black samples. In the context of the worldwide epidemic of obesity, these findings suggest that in developed countries, weight gain prevention efforts might best be focused on those who are most socioeconomically disadvantaged, particularly those in lower status occupations.

Exploding the stability myth : structural change in the Australian trade union movement, 1969-85

Traditional studies of long-term change in trade union structure have predominantly relied upon the aggregate number of trade unions as the principal measure, or indicator of change over time. Using the Australian trade union movement as an example, this article argues that our understanding of the long-term change in the external structure of trade unions would be better served by using Waddington's structural events approach examining the incidence of four distinct 'structural events'--union formations, dissolutions, breakaways and mergers. In doing so, this article presents new data on structural change in the Australian trade union movement between 1969 and 1985. It casts doubt on the traditional argument, which relied on the apparent lack of change in the aggregate number of unions reported by the Australian Bureau of Statistics to argue that this period was one of structural rigidity. The structural events data reveals that far from being a period of structural stability, it was in fact one of significant change, albeit in the composition of the Australian trade union movement, rather than in the aggregate number of trade unions in operation.

Climate change research & responses on the Eyre Peninsula : Weaving natural resources management with community resilience planning

In the last 10 years climate change risk assessment has come to a head as a matter of discussion at all levels of governance. In an attempt to gain a co-ordinated appreciation, measure of scope and impact likelihood, and to better guide a holistic natural resources management strategy, the Eyre Peninsula Natural Resources Management Board has taken a comprehensive exclusive and coordinated approach at a regional level to this issue.

Water, agricultural sustainability, biodiversity enrichment and stabilisation, and community resilience planning are all integral features in this 'program' of research and engagement. The clear intent is to creatively drive change and socio-economic growth without compromising the significant aesthetic and biodiversity attributes of the landscape and its primary role as a dryland wheat producer. The 'program' involves clear practice-based research as to fact, fiction and perception, and the provision of scenarios as to vulnerability and resilience building to cater for climate change over the next 30 years but also to sensitively respond to propective mining growth for the Peninsula.

This paper reviews this 'program', the research and findings undertaken, the co-ordinated actions being taken, the importance of community engagement and resilence building, and the orchestration and propective execution of this 'program' by the Board.

The 'program' represents important case model in successful regional planning.

An efficient one-pass method for discovering bases of recently frequent episodes over online data streams

The knowledge embedded in an online data stream is likely to change over time due to the dynamic evolution of the stream. Consequently, infrequent episode mining over an online stream, frequent episodes should be adaptively extracted from recently generated stream segments instead of the whole stream. However, almost all existing frequent episode mining approaches find episodes frequently occurring over the whole sequence. This paper proposes and investigates a new problem: online mining of recently frequent episodes over data streams. In order to meet strict requirements of stream mining such as one-scan, adaptive result update and instant result return, we choose a novel frequency metric and define a highly condensed set called the base of recently frequent episodes. We then introduce a one-pass method for mining bases of recently frequent episodes. Experimental results show that the proposed method is capable of finding bases of recently frequent episodes quickly and adaptively. The proposed method outperforms the previous approaches with the advantages of one-pass, instant result update and return, more condensed resulting sets and less space usage.

Associations between measures of adiposity over 10 years and patella cartilage in population-based asymptomatic women

Objective: Osteoarthritis (OA) most commonly affects the patellofemoral compartment of the knee, and is a major cause of pain and disability. Structural changes that evolve prior to the onset of symptoms can be visualised using magnetic resonance imaging (MRI). There is little known information about the role of adiposity on the early structural changes in the patella cartilage in younger, asymptomatic adult females.

Methods: One hundred and sixty asymptomatic women (20–49 years) participating in the Geelong Osteoporosis Study underwent knee MRI (2006–8). Weight and body mass index (BMI) were measured 10 years prior (1994–7, baseline) and at the time of MRI (current), with change over the period calculated (current–baseline). Relationships between measures of adiposity and patella cartilage volume and defects were examined.

Results: After adjustment for age and patella bone volume, there was a reduction of 13 ml (95% confidence interval (95% CI), −25.7, −0.55) in patella cartilage volume for every 1 unit increase in current BMI, and a reduction of 27 ml (95% CI −52.6, −1.5) per BMI unit increase over 10 years (P=0.04 for both). No significant association was observed between baseline BMI and patella cartilage volume (P=0.16). Increased baseline and current weight and BMI were associated with increased prevalence of patella cartilage defects (all P<0.001).

Conclusions: Adiposity and weight gain during midlife are associated with detrimental structural change at the patella in young to middle-aged healthy non-osteoarthritic women. Maintaining a healthy weight and avoiding weight gain in younger asymptomatic women may be important in the prevention of patellofemoral OA.

Sleep in high-functioning children with autism : longitudinal developmental change and associations with behavior problems

Sleep disturbance is common in autism spectrum disorder (ASD), but longitudinal trajectories are poorly defined. This study measured sleep disturbance at baseline and 1 year later examining change over time and associated problem behaviors. Participants were 84 gender-matched children, aged between 7 and 12 years at baseline; 46 children were diagnosed with ASD, and 38 were typically developing (TYP) children. Parent reports on a range of scales were collected. The ASD group had more sleep disturbance than the TYP group. Sleep disturbance decreased over the year in children with ASD, but not in TYP children. Reduced sleep disturbance was associated with improved social ability. Sleep disturbance at baseline predicted later anxiety. Findings indicated different trajectories of sleep disturbance in ASD, and the implications are discussed.

Evaluating coverage changes in national parks using a hybrid change detection algorithm and remote sensing

Remote sensing is a useful tool for detecting change over time.We introduce a hybrid change-detection method for forest and protected-area vegetation and demonstrate its use with two satellite images of Golestan National Park in northern Iran (1998 and 2010). We report on the advantages and disadvantages of the hybrid method relative to the standard change-detection method. In the proposed hybrid algorithm, the change vector analysis technique was used to determine changes in vegetation. Following this, we used postclassification comparison to determine the nature of the changes observed and their accuracy and to evaluate the effects of different parameters on the performance of the proposed method. We determined 85% accuracy for the proposed hybrid change-detection method, thus demonstrating a method for discovering and assessing environmental threats to natural treasures. © 2014 Society of Photo-Optical Instrumentation Engineers.

Quality of life improvements after sports injury

Over the past decade, there has been an increase in available data describing the incidence of sports injuries. However, the outcomes of such injuries remain relatively undocumented. Psychological aspects of sports injury rehabilitation have been documented in elite athletes but not in cohorts of general sports participants. The few studies that have described the financial costs of sports injuries have typically not assessed how these injuries affect quality of life. Despite recent estimates that lost quality of life accounts for 81% of total sports injury costs,1 this has received relatively little attention in the literature. The aim of this paper is to describe the quality of life outcomes associated with sports injuries and to present some preliminary observations about how these change over a six-week period.

Normative life satisfaction: measurement issues and a homeostatic model

Previous studies have established that, when life satisfaction is measured over a range from 0 to 100 the mean scores of Western populations average 75 ± 2.5. The consistency of these data has given rise to the idea that life satisfaction may be held under homeostatic control. This paper further investigates this hypothesis by examining the distribution of data within populations. It also examines these data with a view to elucidating various methodological issues regarding life satisfaction measurement. In terms of the methodological issues it is concluded that measurement is best achieved using bi-directional Likert scales with at least 11 choice points. It is also determined that the life satisfaction of Western populations did not change over the decade 1980–1990, and that data derived from college students cannot be validly employed as proxy general population data. In terms of data distribution, it is calculated that the normal range of life satisfaction within Western populations lies within the range 40 to 100. The consistency of this non-normal distribution is argued to be further evidence that life satisfaction is held under homestatic control, and a descriptive model is proposed.

Public definitions of success in weight management

Objective: To examine perceptions of success in weight control and future weight-control intentions in a community sample. Design: Cross-sectional postal survey. Subjects: There were 1500 adults randomly selected from the Electoral Roll of Victoria (47% response). Setting: Community. Main outcome measures: Retrospective weight change over previous 12 months; perceived weight-control success; future weight-control intentions. Statistical analyses: Pearson's χ² tests were used to compare perceived weight-control success by sex, and by age, education level, initial BMI, amount of weight change and weight-loss behaviour within sex. ANOVA was used to compare mean weight change associated with perceived weight control success within sex, and within age, education, body mass index and weight-loss behaviour by sex. The distribution (frequency) of weight-control intentions are reported within perceived weight-control success and amount of weight change. Results: One in two (53%) reported maintaining their weight within 1kg in the preceding 12 months, 26% of men and 21% of women reported weight gain and 20% of men and 26% of women reported weight loss. Almost one-third (30%) of those who maintained their weight considered themselves unsuccessful. A majority of those who lost weight considered themselves successful at controlling their weight. However, more than 45% of men who gained weight also considered themselves successful. Those who considered themselves unsuccessful experienced less weight loss (1.1 ± 3.9kg) than those who considered themselves quite successful (-1.4 ± 4.5 kg, P < 0.001) or very successful (-1.3 ± 7.8 kg, P < 0.001). Conclusion: Public views of what constitutes successful weight control may need to be reoriented to be consistent with public health goals.

Securing institutional legitimacy or organizational effectiveness?

Purpose: The purpose of this paper is to consider the impact of a major initiative (the National Competition Policy) and pieces of legislation (the Local Government Act and the Local Government Finance Standards) on the internal practices of a large Australian local authority.

Design/methodology/approach: A theoretical framework is developed using new public management (NPM) and neo-institutional theory literatures to explain the findings. A case study approach was applied to collect the data for the research.

Findings: The findings reveal that the National Competition Policy 1993, the Local Government Act 1993 and the Local Government Finance Standards 1994 mainly have brought about significant changes to the organisation's internal management control processes, such as financial reporting, budgeting and performance appraisal. The changes brought in appeared to be coincidentally similar to NPM ideals. Furthermore, senior managers (such as the chief executive and divisional heads) played a major role in implementing new accounting technologies (activity-based costing and the balanced scorecard type performance measurement system).

Research limitations/implications: Future research on public sector financial management from the outset of organisational contexts could considerably further the stock of knowledge in this area, especially given the rapid changes occurring within the public sector throughout the world. Future research may wish to extend this study by assessing how external legitimating functions become internal reality, the perceptions of reality of the organisational members, and how these perceptions change over time.

Practical implications: The findings reported provide evidence to further our understanding of how the introduction of private sector styles of organisational practices into large areas of the public sector brought about significant changes in the demand for “new” financial management practices.

Originality/value: The findings reported on in this paper will open a new path of research that may increase our understanding about the factors that play a role in the design of management and accounting systems in a public sector context. Further, they will help policy makers and public sector managers in their day-to-day decision-making.

A longitudinal study of children`s developing knowledge and reasoning in science

The growth in science understanding and reasoning of 12 children is being traced through their primary school years. The paper reports findings concerning children’s growing understandings of evaporation, and their changing responses to exploration activities, that show the complexity and coherence of learning pathways. Children’s responses to identical explorations of flight, separated by two years, are used to explore the interactions between conceptual knowledge and scientific reasoning, and the manner in which they change over this time. The paper discusses the particular insights afforded by a longitudinal study design, and some attendant methodological issues.