A note on influence diagnostics in nonlinear mixed-effects elliptical models

This paper provides general matrix formulas for computing the score function, the (expected and observed) Fisher information and the A matrices (required for the assessment of local influence) for a quite general model which includes the one proposed by Russo et al. (2009). Additionally, we also present an expression for the generalized leverage on fixed and random effects. The matrix formulation has notational advantages, since despite the complexity of the postulated model, all general formulas are compact, clear and have nice forms. (C) 2010 Elsevier B.V. All rights reserved.

Local power of some tests in exponential family nonlinear models

In this paper we obtain asymptotic expansions up to order n(-1/2) for the nonnull distribution functions of the likelihood ratio, Wald, score and gradient test statistics in exponential family nonlinear models (Cordeiro and Paula, 1989), under a sequence of Pitman alternatives. The asymptotic distributions of all four statistics are obtained for testing a subset of regression parameters and for testing the dispersion parameter, thus generalising the results given in Cordeiro et al. (1994) and Ferrari et al. (1997). We also present Monte Carlo simulations in order to compare the finite-sample performance of these tests. (C) 2010 Elsevier B.V. All rights reserved.

From Data Snore, to Data Score: Communicating Library Assessment Data Visually through Infographics

This presentation was offered as part of the CUNY Library Assessment Conference, Reinventing Libraries: Reinventing Assessment, held at the City University of New York in June 2014.

Gait termination in young and older adults : effect of stopping stimulus probability and stimulus delay

Sixteen young (25±2.6 years) and 16 older individuals (69±4.4 years) walked normally then terminated walking rapidly. A visual stopping stimulus was presented 10 ms following ground contact (short delay) and in another condition, at 450 ms prior to toe-off (long delay). Stimulus probability was either high (80% of trials) or low (10%). The younger group stopped faster (463 vs. 574 ms) despite also walking faster (1.29 vs. 1.17 m s⁻¹). Longer delay decreased one-step responses but older participants used significantly more (slower) two-step stopping, which increased stopping time and distance. The additional step may have been pre-planned to maintain medial–lateral stability.

Further examination of relationships between events and psychiatric symptoms in adults with intellectual disability

Background: It has been proposed that people with intellectual disability (ID) might be similar to the general population in the way they respond to significant life events. Some preliminary findings have demonstrated that adults with ID who have experienced recent life events have an increased probability of having psychiatric problems. The aims of the present study were to determine whether previous findings can be replicated, and to examine the influence of additional diagnoses associated with ID on the strength of relationships between life event frequency and psychiatric problems.

Methods: Adults with ID (n = 624), living either in staffed community accommodation or in family or foster homes, were assessed on the Developmental Behaviour Checklist for Adults (DBC-A) and a 37-item life events checklist. Carers who knew the person well acted as proxy informants.

Results: People living in staffed accommodation experienced more life events than people living with natural or foster families. Life event frequency predicted DBC-A total score, five of six sub-scale scores, and caseness status, after significant demographic factors were taken into account. However, the strength of correlations between life event frequency and DBC-A total score varied among sub-groups identified by type of developmental disability and level of ID.

Conclusions: Weak but significant associations between emotional and behavioural problems and life events experienced by adults with ID were demonstrated, but it was also shown that the strength of such associations varies among sub-groups of this heterogeneous population. Future research needs to take account of the circumstances surrounding the life changes, the period of time over which changes might have taken place, and the meaning that the person might attach to the changes. Research into the causal relationship between exposure to life events and the onset of psychiatric problems is also warranted.

The body keeps the score

American animator Robert Breer has been credited in introducing the first visual bomb to cinema in his loop film Image by Images I (1954), Two abstract animated films by Robert Breer are examined: 69 (1968 5 minutes) and Fuji (1974 10 minutes). Using Merleau-Ponty’s phenomenological perspective, though these films are not representational or photographic in the traditional sense it is argued that they are still able to talk to us about real experiences because ‘the lived perspective, that which we actually perceive, is not a geometric or photographic one.’(Merleau-Ponty, 1964b: 14) 69 provides a metaphor for a system that collapses and Fuji as an articulation of that embodied seeing required for train travel. It is argued that Breer’s work in its explorations of style ahead of content is research into an act of viewing that offers a contemporary simulation of the impact of a traumatic experience on the body. Just as one cannot grab each object in the landscape at the speed of train travel nor can one grab or understand each frame that is presented to the retina of a Robert Breer film. What is required to attain “stillness” is a more dissociated way of looking that allows the images to wash over you. Such a “stillness” may be more about suppression than contemplation and could involve a process of metamorphosis.

A diagnostic 'profile' for chance (probability)

This article presents a profiling tools for identifying students knowledge in chance.

Ambulance call triage outcomes for patients reporting pain : a retrospective cross-sectional analysis of pain score versus traige level

Objective: To identify any association between the response priority code generated during calls to the ambulance communication centre and patient reports of pain severity.

Methods: A retrospective analysis of patient care records was undertaken for all patients transported by paramedics over a 7-day period. The primary research interest was the association between the response code allocated at the time of telephone triage and the initial pain severity score recorded using a numeric rating scale (NRS). Univariate and multivariate logistic regression methods were used to analyse the association between the response priority variable and explanatory variables.

Results: There were 1246 cases in which both an initial pain score using the NRS and a response code were recorded. Of these cases, 716/1246 (57.5%) were associated with a code 1 ("time-critical") response. After adjusting for gender, age, cause of pain and duration of pain, a multivariate logistic regression analysis found no significant change in the odds of a patient in pain receiving a time-critical response compared with patients who had no pain, regardless of their initial pain score (NRS 1–3, odds ratio (OR) 1.11, 95% CI 0.7 to 1.8; NRS 4–7, OR 1.12, 95% CI 0.7 to 1.8; NRS 8–10, OR 0.84, 95% CI 0.5 to 1.4).

Conclusion: The severity of pain experienced by the patient appeared to have no influence on the priority (urgency) of the dispatch response. Triage systems used to prioritise ambulance calls and decide the urgency of response or type of referral options should consider pain severity to facilitate timely and humane care.

A conditional probability approach to risk assessment for child sexual offenders with different classes of victim

Specific scales were developed for discriminating child sexual offenders with different classes of victim. The project demonstrates a method of individualising scores on actuarial risk assessment measured in a way that makes them more meaningful for those involved in decision-making about individual child sexual offenders. At present, the only quantifiable approach to specific decision-making relies on a general prediction of future behaviour, based on group data. The Bayesian approach is one method that can be used to assist decision-makers to use this information in ways that lead to the more appropriate management of risk. Ultimately, the better management of known child sexual offenders will lead to fewer offences and a reduction in the number of children who lives are profoundly affected by sexual victimisation.

Can the ABCD Score be dichotomised to identify high−risk patients with trainsient ischaemic attack in the emergency department?

Background: Recent evidence shows a substantial short-term risk of ischaemic stroke after transient ischaemic attack (TIA). Identification of patients with TIA with a high short-term risk of stroke is now possible through the use of the “ABCD Score”, which considers age, blood pressure, clinical features and duration of symptoms predictive of stroke.

Aim: To evaluate the ability of dichotomising the ABCD Score to predict stroke at 7 and 90 days in a population with TIA presenting to an emergency department.

Methods: A retrospective audit was conducted on all probable or definite TIAs presenting to the emergency department of a metropolitan hospital from July to December 2004. The ABCD Score was applied to 98 consecutive patients with TIA who were reviewed for subsequent strokes within 90 days. Patients obtaining an ABCD Score ≥5 were considered to be at high risk for stroke.

Results: Dichotomising the ABCD Score categorised 48 (49%) patients with TIA at high risk for stroke (ABCD Score ≥5). This high-risk group contained all four strokes that occurred within 7 days (sensitivity 100% (95% confidence interval (CI) 40% to 100%), specificity 53% (95% CI 43% to 63%), positive predictive value 8% (95% CI 3% to 21%) and negative predictive value 100% (95% CI 91% to 100%)), and six of seven occurring within 90 days (sensitivity 86% (95% CI 42% to 99%), specificity 54% (95% CI 43% to 64%), positive predictive value 12.5% (95% CI 5% to 26%) and negative predictive value 98% (95% CI 88% to 100%)). Removal of the “age” item from the ABCD Score halved the number of false-positive cases without changing its predictive value for stroke.

Conclusion: In this retrospective analysis, dichotomising the ABCD Score was overinclusive but highly predictive in identifying patients with TIA at a high short-term risk of stroke. Use of the ABCD Score in the emergency care of patients with TIA is simple, efficient and provides a unique opportunity to prevent stroke in this population of patients.