Biomedical subjects

S A Ackroyd-Stolarz

Publications and source records attributed to S A Ackroyd-Stolarz.

7 recordsLinked to original sources

PubMed2004

Patients with community acquired pneumonia discharged from the emergency department according to a clinical practice guideline.

OBJECTIVES: To assess the safety of discharging patients with community acquired pneumonia (CAP) according to a clinical practice guideline. METHODS: A systematic retrospective review of medical records of 867 adult patients discharged from an emergency department (ED) with CAP between 3 January 1999 and 3 January 2001. Readmission or death rates within 30 days of discharge were evaluated, using data from all local hospitals and from the provincial coroner. RESULTS: Of 685 patients with pneumonia severity index (PSI) scores of <91, 13 (1.9%) were readmitted and five (0.76%) died within 30 days of the ED visit. Thirty day readmission and death rates for patients with PSI >90 were 7.14% (13 of 182) and 9.34% (17 of 182), respectively. CONCLUSION: Adult patients with CAP discharged from the ED according to the recommendations of a clinical practice guideline based on the PSI have low readmission and death rates, and are generally safely managed as outpatients.

Adult↗

PubMed1997

Effects of rear-wheel camber on wheelchair stability.

OBJECTIVES: To evaluate how using a wheelchair with rear-wheel camber (when the bottoms of the wheels are farther apart than the tops) is associated with the risk of instability incidents, and to determine the effect of camber on wheelchair stability. DESIGN, SETTING, PATIENTS: Epidemiologic data were analyzed from a sample of 576 users of manually propelled wheelchairs in Nova Scotia. A controlled trial was performed using a representative wheelchair occupied by an anthropomorphic test dummy, altering the camber in 5 degrees increments from -15 degrees to +15 degrees. MAIN OUTCOME MEASURES: For the epidemiologic study, univariate and multivariate analyses were used. To measure the static stability, a tilting platform was used according to the guidelines of the International Organization for Standardization. RESULTS: Camber users reported significantly more instability incidents; of these incidents, more were in the rear direction (40% vs 27%) and fewer in the lateral direction (17% vs 28%) (p < .01). When controlling for other factors, camber was associated with a 3.91-fold increased risk of sustaining an instability incident (p < .001). With increases in camber angle in the laboratory, lateral and forward stability increased and rear stability decreased (with the wheels unlocked and locked) (p < .001). CONCLUSION: Camber use is negatively associated with instability incidents in the lateral direction and positively associated with incidents in the backward direction, probably due in part to the effects of camber on lateral and rear stability.

Accident Prevention↗

PubMed1996

Adding loads to occupied wheelchairs: effect on static rear and forward stability.

OBJECTIVE: To determine the extent to which loads added in different positions affect the static rear and forward stability of an occupied wheelchair. DESIGN: Controlled, cross-over study. INTERVENTION: Loads from 0 to 10kg (in 1-kg increments) were added to five positions: high rear (HR), low rear (LR, beneath the seat and behind the crossbrace), on the lap (LAP), low anterior (LA, beneath the seat and anterior to the crossbrace), and on the footrests (FR). We also used a computer model to evaluate the relationship between stability and load, with a range of loads (0 to 100kg, in 10-kg increments) beyond the loads that were practical to test empirically. OUTCOME MEASURE: On a tilting platform, we measured the static stability (in degrees) of a wheelchair occupied by an anthropomorphic test dummy (ATD). RESULTS: The greatest increase in rear stability was with FR loads, changes of 64% and 227% for 10-kg and 100-kg loads, respectively. Only HR loads reduced rear stability, by 32% and 64%. The greatest increase in forward stability was with LR loads, by 13% and 92%. The greatest reduction in forward stability was with FR loads, by 10% and 149%. To minimize the effect of added loads on stability, the LAP and LA positions would be preferred. CONCLUSION: Added loads affect wheelchair stability as a function of the load magnitude. The extent and direction of the effect is profoundly influenced by load position.

Accidents↗

PubMed1994

Wheelchair stability and maneuverability: effect of varying the horizontal and vertical position of a rear-antitip device.

Although properly adjusted rear-antitip devices on wheelchairs prevent rear-tipping accidents, many wheelchair users do not use them because they limit manueverability. This study evaluated the use and effectiveness of antitip devices, particularly the effect of the devices' position on rear stability and maneuverability. In an epidemiologic study of the use of antitip devices, using a database of noninstitutionalized users of manually propelled chairs, we found no significant difference in the incidence or nature of rear-tipping accidents between the 167 who used antitip devices and the 399 who did not. We also evaluated seven common manually propelled wheelchairs, occupied by an anthropomorphic test dummy, with and without antitip devices. The added stability provided by the antitip devices varied considerably (from -1.0 to 27.1 degrees) depending on the type of chair, the configuration of the chair and the position of the antitip device. A representative wheelchair was then equipped with an adjustable antitip device that allowed us to test 68 combinations of vertical and horizontal positions. The relationships between the position of the antitip device and both the measured rear-stability and maneuverability values could be expressed by significant regression equations, and correlated highly with the values predicted by a theoretical model that we developed. These relationships should assist clinicians, users and wheelchair designers in finding appropriate compromises between safety and maneuverability.

Accidental Falls↗

PubMed1993

Influence of seat position on the static and dynamic forward and rear stability of occupied wheelchairs.

We tested the hypothesis that moving the seat of an occupied wheelchair forward would decrease the wheelchair's forward and increase its rear static and dynamic rotational stability, and that moving the seat backward would have the opposite effect. We studied 21 able-bodied subjects in a lightweight, manually propelled wheelchair with the occupied seat in the normal position, 5cm forward, and 5cm backward. Regression analysis revealed that, within the range studied, the relationship between seat position (chi, in cm) and the forward and rear static stability (SSf and SSr, in degrees) could be expressed by the linear equations SSf = 15.52 (0.06)-0.70 (0.01) chi (r2 = 0.98) and SSr = 24.55 (0.07) + 1.11 (0.02) chi (r2 = 0.99). These findings were consistent with the results of a computer model that we used to predict the nature and extent of the effect on static stability, except that the model showed that the relationship becomes nonlinear with seat-position changes greater than those we studied. The relationship between seat position and dynamic forward and rear stability (DSf and DSr, the threshold speed [in m/s] required to induce a transient tip) could be expressed by the equations DSf = 0.74 (0.01)-0.041 (0.002) chi (r2 = 0.91) and DSr = 0.63 (0.01) + 0.030 (0.002) chi (r2 = 0.91). The results support our hypothesis and indicate that seat position is a very significant determinant of wheelchair stability.

Adult↗

PubMedDate not supplied

Wheelchair-related accidents caused by tips and falls among noninstitutionalized users of manually propelled wheelchairs in Nova Scotia.

The purpose of this study was to document what proportion of noninstitutionalized users of manually propelled wheelchairs are affected by wheelchair-related accidents caused by tips and falls, determine the nature and severity of the resulting injuries, and, by comparison with an unaffected group, identify factors associated with the risk of such accidents. We administered a postal questionnaire to as many as possible of the estimated 2055 members of the target population in the province of Nova Scotia. Among the 577 appropriate respondents, 57.4% reported they had completely tipped over or fallen from their wheelchairs at least once, and 66.0% reported having partially tipped. Of the falls and tips that were reported, 46.3% were forward in direction, 29.5% backward and 24.2% sideways. Many of the accidents occurred outdoors or on ramps. A total of 292 injuries were reported by 272 (47.1%) respondents. Most of the injuries (84.3%) were minor (e.g., abrasions, contusions, lacerations and sprains). Of the 15.8% of injuries that were serious, the most common were fractures (10.6%) and concussions (2.7%). Factors that appear to be associated with an increased risk of accidents and injuries included younger age, male gender, paraplegia or spina bifida as the reason for wheelchair use, having had a wheelchair prescribed, some wheelchair features (lightweight, camber, adjustable rear-axle positions, a knapsack), daily use of a wheelchair, propelling the chair with both hands, use of the wheelchair for recreation, use of a sideways transfer (without a transfer board) and doing repairs themselves or having them done by the dealer. Factors associated with a decreased risk include multiple sclerosis, stroke or arthritis as the reason for wheelchair use, attendant propulsion and the use of a one-person assist for transfers. The results of this study, that wheelchair-related accidents caused by tips and falls are very common, that serious injuries are not unusual and that there is a pattern of risk factors, should be useful to wheelchair users, clinicians, manufacturers and regulatory bodies.

Accidents↗

PubMedDate not supplied

Wheelchair safety--adverse reports to the United States Food and Drug Administration.

Evidence has been accumulating that injuries related to wheelchair use are common and sometimes serious. The object of this study was to evaluate the databases of the Food and Drug Administration (FDA) for insights to the nature and causes of such problems. We analyzed 651 records that were received by the FDA between 1975 and 1993. There were 368 injuries, 21 of which were fatal, affecting 334 wheelchair users. Fractures were the most common (45.5%), with lacerations (22.3%) and contusions/abrasions (20.1%) accounting for most of the remainder. The proportion of incidents related to the use of scooters, powered wheelchairs, and manual wheelchairs were 52.8%, 24.6%, and 22.6%, respectively. Four broad classes of contributing factors, often acting in combination, were implicated: engineering (60.5%), environmental (25.4%), occupant (9.6%), and system (4.6%). Of the tips and falls, those in the forward direction were most common in incidents affecting manual or powered wheelchairs, but the sideways direction was most common in scooters. The FDA database provides a unique perspective on wheelchair safety, with implications for clinicians, users, manufacturers, and regulatory bodies.

Equipment Design↗