Validation of the completeness and accuracy of the Northern Ireland Cancer Registry.

BACKGROUND: It has been suggested that inaccuracies in cancer registries are distorting UK survival statistics. This study compared the Northern Ireland Cancer Registry (NICR) database of living patients, with independent data held by Northern Ireland's General Practitioners (GPs) to compare and validate the recorded diagnoses and dates held by the registry. METHODS: All 387 GP practice managers were invited to participate. 100 practices (25.84%) responded. Comparisons were made for 17,102 patients, equivalent to 29.08% of the living patients (58,798) extracted from the NICR between 1993 and 2010. RESULTS: There were no significant differences (p>0.05) between the responding and nonresponding GP patient profiles for age, marital status or deprivation score. However, the responding GPs included more female patients (p=0.02). NICR data accuracy was high, 0.08% of GP cancer patients (n=15) were not included in registry records and 0.02% (n=2) had a diagnosis date which varied more than 2 weeks from GP records (3 weeks and 5 months). The NICR had recorded two different tumour types and three different tumour statuses (benign vs. malignant) to the GPs. CONCLUSION: This comparison demonstrates a high level of accuracy within the NICR and that the survival statistics based on this data can be relied upon.

Strength of evidence, judged probability, and choice under uncertainty.

This paper traces, within subjects, the relationship between assessed strength of evidence, judgments of probability, and decisions under uncertainty. The investigation relies on the theoretical framework provided by support theory (Tversky & Koehler, 1994; Rottenstreich & Tversky, 1997), a nonextensional model of judgment under uncertainty. Fans of professional basketball (N = 50) judged the probability that each of eight teams, four divisions, and two conferences would win the National Basketball Association championship. Additionally, participants rated the relative strength of each team, judged the probability that a given team would win the championship assuming a particular pairing in the finals, priced prospects contingent on the winner of the championship, and made choices between chance prospects. The data conformed to the major tenets of support theory, and the predicted relationships between assessed strength of evidence, hypothetical support, judged probabilities, and choices under uncertainty also held quite well.

Some visual influences on human postural equilibrium: binocular versus monocular fixation.

The importance of vision for postural equilibrium has long been known; traditionally, this visual contribution to the control of posture has been analyzed primarily in terms of optical and retinal phenomena. Recently, however, there has been some suggestion that binocular and monocular fixation of identical stimuli have differential effects. Three experiments were conducted in order to measure self-generated movement (sway during quiet standing) of the body's center of gravity while field structure, ankle proprioception, and binocular/monocular fixation were varied. Field structure was varied from total darkness, to the presence of single and multiple LEDs in the dark, to full field structure (i.e., the richness of the feed back information was varied). Ankle proprioception was varied by changing foot position from side-by-side to heel-to-toe positions. Results indicate that (1) ankle-joint input is a significant factor in reducing sway, (2) binocular fixation attenuates sway relative to monocular fixation, under otherwise identical visual conditions, and (3) this difference persists in total darkness. Taken together, the data indicate that the visual influence on postural equilibrium results from a complex synergy that receives multimodal inputs. A simple optical/retinal explanation is not sufficient.

Effect of head orientation on human postural stability following unilateral vestibular ablation.

Effective interpretation of vestibular inputs to postural control requires that orientation of head on body is known. Postural stability might deteriorate when vestibular information and neck information are not properly coupled, as might occur with vestibular pathology. Postural sway was assessed in unilateral vestibulopathic patients before and acutely, 1, 4, and 18+ months after unilateral vestibular ablation (UVA) as well as in normal subjects. Postural equilibrium with eyes closed was quantified as scaled pk-pk sway during 20 s trials in which the support surface was modulated proportionally with sway. Subjects were tested with the head upright and facing forward, turned 45 degrees right, and 45 degrees left. Equilibrium was uninfluenced by head orientation in normal subjects. In contrast, patients after UVA showed both a general reduction in stability and a right/left head orientation-dependent asymmetry. These abnormalities adaptively recovered with time. It is concluded that vestibular inputs to postural control are interpreted within a sensory-motor context of head-on-body orientation.

Visually perceived eye level and perceived elevation of objects: linearly additive influences from visual field pitch and from gravity.

Observing a pitched visual field (i.e. tilted around a horizontal axis in the observer's frontal plane) results in large changes in the elevation visually perceived to correspond to eye level (VPEL) and in the perceived elevation and size of stationary objects viewed against the field. With topforward pitch (top toward observer) VPEL lies above true eye level and objects appear smaller and lower; with topbackward pitch VPEL lies below true eye level and objects appear larger and higher. Oscillation of the pitched field induces synchronous perceived oscillation of elevation of a stationary target viewed against the field. Typical VPEL settings deviated from true eye level by 20 degrees with the field pitched at 40 degrees, although some individuals mislocalized by as much as 40 degrees. VPEL varied linearly with visual field pitch with individual slopes for the relation between VPEL and visual field pitch ranging from +0.42 to +0.78 (avg = +0.56). The linear correlation (r) between VPEL in darkness and against an erect visual field was +0.91. The two relations--VPEL vs visual field pitch, VPEL in darkness vs VPEL in the erect illuminated visual field (slope approximately equal to 0.5)--are both accurately predicted by the linear model: VPEL = kvV + kbB; in which V is the influence of visual field structure and B is the influence of the body-referenced mechanism which combines information regarding the orientation of the head relative to gravity, the position of the eye in the orbit, and the vertical location of the image on the retina; kv and kb are the relative weights of V and B with kv + kb = 1. In an illuminated field kv = kb approximately equal to 0.5; in the dark kv = 0, kb = 1.

A model of spatial localization and its application to strabismus.

Visually guided, spatially oriented behavior involves an ongoing integration of signals regarding the loci of the retinal images and the position and orientation of the eye. In the strabismic this requires an altered spatial metric resulting from a functional readaptation to avoid confusion and diplopia. A comparator mechanism for evaluating these two signals is presented. A case report using "disruptive" therapeutic procedures that deliberately alter the strabismic's visual-postural control system is presented. A treatment plan for altering the anomalous binocular link, a characteristic of the well adapted strabismic, is described and related to the comparator mechanism.