Biomedical subjects

Donald E Parker

Publications and source records attributed to Donald E Parker.

9 recordsLinked to original sources

PubMed2006

The Soterion Rapid Triage System: evaluation of inter-rater reliability and validity.

The Soterion Rapid Triage System is a new, computerized, five-level triage acuity system. The purpose of this study was to evaluate the system's inter-rater reliability and validity for stratifying patient acuity. The study was comprised of two components. A prospective evaluation of inter-rater reliability was conducted by the blinded, paired simultaneous triage of 423 patients. A retrospective evaluation of validity consisted of the analysis of 33,850 patients triaged with the system over an 8-month period. The system's validity was measured by in-hospital admission rate, Emergency Department (ED) length-of-stay, hospital charges and Current Procedural Terminology (CPT) Codes 99281-99285. Evaluation of inter-rater reliability demonstrated a weighted kappa of 0.87 (95% confidence interval 0.84, 0.91). The in-hospital admission rates for patients triaged as Level 1 Immediate-Level 5 Non-Urgent were 43%, 30%, 13%, 3% and 1%, respectively (p < 0.0001). Similarly, there were significant differences in the means for all hospital charges, ED lengths-of-stay, and CPT Codes. In conclusion, the Soterion Rapid Triage System possesses high inter-rater reliability and validity. The system's reliability and validity, and the availability of the system's electronically archived data are characteristics beneficial to the development of a national standardized five-level triage acuity system.

Algorithms↗

PubMed2006

The use of the Soterion Rapid Triage System in children presenting to the Emergency Department.

There has been a recent move toward the adoption of five-level triage systems in the United States. However, there have been no studies in this country that have critically evaluated the use of these systems in children. The purpose of this study was to evaluate the reliability and validity of a new five-level triage system, the Soterion Rapid Triage System, for stratifying acuity levels in children under the age of 13 years. The study was conducted in a 389-bed Level II mixed adult and pediatric Trauma Center that experiences approximately 12,000 patient visits/year of children under the age of 13 years. We performed a prospective evaluation of the system's reliability using the weighted kappa statistical method (n = 117) and a retrospective evaluation of the system's validity through an analysis of all patients under the age of 13 years triaged with the system over an 8-month period (n = 7077). The system's validity was measured by in-hospital admission rate, Emergency Department length of stay, hospital charges, and Current Procedural Terminology (CPT) Codes 99281-99285. The inter-rater reliability as measured by the weighted kappa was 0.90 (95% confidence interval 0.83-0.96), with 92% exact agreement between nurses in the triage level assigned. The in-hospital admission rates for patients triaged as Level 1 Immediate-Level 5 Non-Urgent were 38%, 18%, 9%, 1.5% and 0.4%, respectively (p < 0.0001). The mean total hospital charges for each of the five triage levels were $2673, $1563, $1112, $477, and $258, respectively (p < 0.0001). Similarly, there were significant differences in the means for laboratory and pharmacy charges, Emergency Department lengths of stay, and CPT Codes. This report represents the first study in this country on the effectiveness of a five-level triage system in children. We have demonstrated that the Soterion Rapid Triage System possesses high inter-rater reliability and validity when used to triage children younger than 13 years of age.

Algorithms↗

PubMed2006

Metabolic syndrome impairs physical function, health-related quality of life, and peripheral circulation in patients with intermittent claudication.

PURPOSE: This study was conducted to (1) examine the effect of metabolic syndrome on intermittent claudication, physical function, health-related quality of life, and peripheral circulation in patients with peripheral arterial disease (PAD), and (2) determine whether peripheral vascular function was predictive of intermittent claudication and physical function in patients with metabolic syndrome. METHODS: Patients limited by intermittent claudication and who had metabolic syndrome (n = 133) were compared with those without metabolic syndrome (n = 201). Patients were assessed on metabolic syndrome characteristics, PAD-specific measures consisting of ankle/brachial index and claudication distances, physical function measures, health-related quality of life, and calf blood flow and transcutaneous oxygen tension responses after 3 minutes of vascular occlusion. RESULTS: Initial claudication distance (mean +/- SD) was 29% shorter (P = .018) in patients with metabolic syndrome than in the controls (128 +/- 121 meters vs 180 +/- 166 meters), and absolute claudication distance was 22% shorter (P = .025) in those with metabolic syndrome (319 +/- 195 meters vs 409 +/- 255 meters). Furthermore, patients with metabolic syndrome had lower peak oxygen uptake (P = .037), a shorter 6-minute walk distance (P = .027), lower values on six domains of health-related quality of life (P < .05), reduced calf hyperemia (P = .028), and greater calf ischemia (P < .001) after vascular occlusion. In the group with metabolic syndrome, calf ischemia was correlated with initial claudication distance (r = 0.30, P = .004), absolute claudication distance (r = 0.40, P < .001), and peak oxygen uptake (r = 0.52, P < .001). CONCLUSION: Metabolic syndrome worsens intermittent claudication, physical function, health-related quality of life, and peripheral circulation in patients with PAD. Calf ischemia in those with metabolic syndrome was predictive of intermittent claudication and physical function. The additive burden of metabolic syndrome thus places patients who are limited by intermittent claudication at an even greater risk for living a functionally dependent lifestyle. Aggressive risk-factor modification designed to treat components of metabolic syndrome should be evaluated for efficacy in modifying physical and vascular function in patients with intermittent claudication.

Aged↗

PubMed2004

"Conflicting" motion cues to the visual and vestibular self-motion systems around 0.06 Hz evoke simulator sickness.

The basic question this research addressed was, how does simulator sickness vary with simulated motion frequency? Participants were 11 women and 19 men, 20 to 63 years of age. A visual self-motion frequency response curve was determined using a Chattecx posture platform with a VR4 head-mounted display (HMD) or a back-projected dome. That curve and one for vestibular self-motion specify a frequency range in which vestibular and visual motion stimuli could produce conflicting self-motion cues. Using a rotating chair and the HMD, a third experiment supported (p < .01) the hypothesis that conflicting cues at the frequency of maximum "crossover" between the curves (about 0.06 Hz) would be more likely to evoke simulator sickness than would conflicting cues at a higher frequency. Actual or potential applications of this work include a preliminary design guidance curve that indicates the frequency range of simulated motion that is likely to evoke simulator or virtual reality sickness; for simulators intended to operate in this frequency range, appropriate simulator sickness interventions should be considered during the design process.

Computer Simulation↗

PubMed2003

The effect of changing from glasses to soft contact lenses on myopia progression in adolescents.

At the end of a clinical trial of bifocals as myopia treatment, subjects were allowed to select any type of optical correction they wished and were asked to return in 1 year. This report gives results of that last examination with emphasis on how progression rates differed between those remaining in their original type of glasses compared with those who switched to soft contact lenses. We found that myopia progressed at an age-adjusted average rate of 0.74 D in 19 children who switched to soft contact lens wear compared with 0.25 D for 24 children remaining in glasses (p < 0.0001). Increased growth of the vitreous chamber appeared to account for much of this excess myopia progression, although the difference in that variable did not reach statistical significance (p = 0.101). We also noted a 0.203 D steepening in the corneal curvature in contact lens wearers compared with spectacle wearers whose corneas steepened very little (0.014 D, p = 0.007). Soft contact lens wear was also accompanied by a greater change in the near-point phoria which moved 4.5 prism dioptres in the exo direction compared with spectacle wearers who experienced only a 1.4 prism dioptre divergent shift (p = 0.048).

Adolescent↗

PubMed2003

Spatial perception changes associated with space flight: implications for adaptation to altered inertial environments.

Preparation for extended travel by astronauts within the Solar System, including a possible manned mission to Mars, requires more complete understanding of adaptation to altered inertial environments. Improved understanding is needed to support development and evaluation of interventions to facilitate adaptations during transitions between those environments. Travel to another planet escalates the adaptive challenge because astronauts will experience prolonged exposure to microgravity before encountering a novel gravitational environment. This challenge would have to be met without ground support at the landing site. Evaluation of current adaptive status as well as intervention efficacy can be performed using perceptual, eye movement and postural measures. Due to discrepancies of adaptation magnitude and time-course among these measures, complete understanding of adaptation processes, as well as intervention evaluation, requires examination of all three. Previous research and theory that provide models for comprehending adaptation to altered inertial environments are briefly examined. Reports from astronauts of selected pre- in- and postflight self-motion illusions are described. The currently controversial tilt-translation reinterpretation hypothesis is reviewed and possible resolutions to the controversy are proposed. Finally, based on apparent gaps in our current knowledge, further research is proposed to achieve a more complete understanding of adaptation as well as to develop effective counter-measures.

Adaptation, Psychological↗

PubMed2002

Effects of characteristics of image quality in an immersive environment.

Image quality issues such as field of view (FOV) and resolution are important for evaluating "presence" and simulator sickness (SS) in virtual environments (VEs). This research examined effects on postural stability of varying FOV, image resolution, and scene content in an immersive visual display. Two different scenes (a photograph of a fountain and a simple radial pattern) at two different resolutions were tested using six FOVs (30, 60, 90, 120, 150, and 180 deg.). Both postural stability, recorded by force plates, and subjective difficulty ratings varied as a function of FOV, scene content, and image resolution. Subjects exhibited more balance disturbance and reported more difficulty in maintaining posture in the wide-FOV, high-resolution, and natural scene conditions.

Adult↗

PubMed2002

Elevated antibody to D-alanyl lipoteichoic acid indicates caries experience associated with fluoride and gingival health.

: BACKGROUND: Acidogenic, acid-tolerant bacteria induce dental caries and require D-alanyl glycerol lipoteichoic acid (D-alanyl LTA) on their cell surface. Because fluoride inhibits acid-mediated enamel demineralization, an elevated antibody response to D-alanyl LTA may indicate subjects with more acidogenic bacteria and, therefore, an association of DMFT with fluoride exposure and gingival health not apparent in low responders. METHODS: Cluster analysis was used to identify low antibody content. Within low and high responders (control and test subjects), the number of teeth that were decayed missing and filled (DMFT), or decayed only (DT) were regressed against fluoride exposure in the water supply and from dentrifice use. The latter was determined from gingival health: prevalences of plaque (PL) and bleeding on probing (BOP), and mean pocket depth (PD). Age was measured as a possible confounding cofactor. RESULTS: In 35 high responders, DMFT associated with length of exposure to fluoridated water (F score), PL and BOP (R2 = 0.51, p < 0.001), whereas in 67 low D-ala-IgG responders, DMFT associated with PL, age, and PD (R2 = 0.26, p < 0.001). BOP correlated strongly with number of 7 7 decayed teeth (DT) in 54 high responders (R2 = 0.57, p < 0.001), but poorly in 97 low responders (R2 = 0.12, p < 0.001). The strength of the PD association with DMFT, or of BOP with DT, in high responders significantly differed from that in low responders (p < 0.05). CONCLUSION: Caries associates with gingival health and fluoridated water exposure in high D-alanyl LTA antibody responders.

Journal Article↗

PubMed2002

A randomized clinical trial of bifocal glasses for myopic children with esophoria: results after 54 months.

BACKGROUND: We previously reported results of a randomized clinical trial of bifocals as a type of myopia correction for children with near-point esophoria. After 30 months, the rate of myopia progression in 36 children wearing bifocals averaged 0.40 D/yr compared to 0.50 D/yr in 39 children wearing single-vision glasses (p= 0.046, age-adjusted). Here we report on the 46 children in that study who completed 54 months of followup. METHODS: For each treatment group, we examined the pattern of change in myopia over the first and second halves of the 54-month period to see if the beneficial effect of wearing bifocals was present initially for those 46 children, as it was in the entire group, and to see if the myopia-slowing effect continued to accumulate during the second part of the study. During the last 12 months of the 54-month period, subjects were free to select any mode of myopic treatment, but this intent-to-treat analysis classified all children according to their original treatment assignment. RESULTS: During the first 24 months, the pattern of change in myopia differed between the two groups (p = 0.041), with those in bifocals showing slower progression. A similar trend was observed for vitreous chamber growth (p= 0.059). During the last 30 months, myopia progressed at a similar rate for both groups, including during the last year, when many subjects changed their mode of myopia correction. CONCLUSION: Wearing bifocals instead of single-vision glasses caused a slowing of myopia progression evident during the first two years. During the subsequent two-and-a-half years of followup, the difference in the degree of myopia was maintained, but did not increase.

Child↗