A realist evaluation of a physical activity participation intervention for children and youth with disabilities: what works, for whom, in what circumstances, and how?

BACKGROUND: The need to identify strategies that facilitate involvement in physical activity for children and youth with disabilities is recognised as an urgent priority. This study aimed to describe the association between context, mechanisms and outcome(s) of a participation-focused physical activity intervention to understand what works, in what conditions, and how. METHODS: This study was designed as a realist evaluation. Participant recruitment occurred through purposive and theoretical sampling of children and parents participating in the Local Environment Model intervention at Beitostolen Healthsports Centre in Norway. Ethnographic methods comprising participant observation, interviews, and focus groups were employed over 15 weeks in the field. Data analysis was completed using the context-mechanism-outcome framework of realist evaluation. Context-mechanism-outcome connections were generated empirically from the data to create a model to indicate how the program activated mechanisms within the program context, to enable participation in physical activity. RESULTS: Thirty one children with a range of disabilities (mean age 12y 6 m (SD 2y 2 m); 18 males) and their parents (n = 44; 26 mothers and 18 fathers) participated in the study. Following data synthesis, a refined program theory comprising four context themes, five mechanisms, and six outcomes, were identified. The mechanisms (choice, fun, friends, specialised health professionals, and time) were activated in a context that was safe, social, learning-based and family-centred, to elicit outcomes across all levels of the International Classification of Functioning, Disability and Health. CONCLUSIONS: The interaction of mechanisms and context as a whole facilitated meaningful outcomes for children and youth with disabilities, and their parents. Whilst optimising participation in physical activity is a primary outcome of the Local Environment Model, the refined program theory suggests the participation-focused approach may act as a catalyst to promote a range of outcomes. Findings from this study may inform future interventions attempting to enable participation in physical activity for children and youth with disabilities.

Pulmonary function, exercise capacity and physical activity participation in adults following burn.

PURPOSE: To determine the relationship between pulmonary function, aerobic exercise capacity and physical activity participation in adults following burn. METHODS: Eight burn injured males aged 20-55 years (%TBSA 33.3±18.7, 5.1 years±1.8 post injury), and 30 healthy adult controls participated. Pulmonary function was assessed during rest via spirometry. A graded exercise test measuring peak oxygen consumption (VO(2peak)) and oxygen saturation (S(p)O(2)) was conducted, and physical activity was assessed via the Older Adult Exercise Status Inventory (OA-EI). RESULTS: No significant correlation was observed between resting pulmonary function, aerobic capacity and physical activity participation for burn injured patients or controls. Two burn injured patients presented with obstructive ventilatory defects, and one displayed a restrictive ventilatory defect. Burn injured patients had a significantly lower VO(2peak) (p<0.001) and time to fatigue (p=0.026), and a greater degree of oxygen desaturation (p=0.063, Effect Size=1.02) during a graded exercise test. Burn injured patients reported significantly less participation in leisure-related activity>9 METs (p=0.01), and significantly greater participation in work-related activity (p=0.038), than healthy controls. CONCLUSION: Compromised lung function, decreased aerobic capacity and reduced participation in leisure-related physical activity may still exist in some adults, even up to 5 years post injury. Limitations and long term outcomes of cardiopulmonary function and physical fitness need to be considered in the prescription of exercise rehabilitation programmes following burn.

Strategies for dose reduction in ordinary radiographic examinations using CR and DR.

Uncoupling of display from acquisition in computed radiography (CR) and digital radiography (DR) introduces the potential for systematic overexposure without necessarily compromising image quality. Although the magnitude of radiation doses in general radiography is low compared to computed tomography and fluoroscopy, the dose to the patient is more critical in pediatric examinations than in adults, because of the greater radiosensitivity of children. This manuscript examines a variety of countermeasures for managing radiation doses in pediatric CR and DR examinations, including use of derived exposure indicators, modifications of imaging practice, and development of more efficient radiographic detectors.

Puncture-proof picture archiving and communication system.

As we become increasingly dependent on our picture archiving and communications system (PACS) for the clinical practice of medicine, the demand for improved reliability becomes urgent. Borrowing principles from the discipline of Reliability Engineering, we have identified components of our system that constitute single points of failure and have endeavored to eliminate these through redundant components and manual work-around procedures. To assess the adequacy of our preparations, we have identified a set of plausible events that could interfere with the function of one or more of our PACS components. These events could be as simple as the loss of the network connection to a single component or as broad as the loss of our central data center. We have identified the need to continue to operate during adverse conditions, as well as the requirement to recover rapidly from major disruptions in service. This assessment led us to modify the physical locations of central PACS components within our physical plant. We are also taking advantage of actual disruptive events coincident with a major expansion of our facility to test our recovery procedures. Based on our recognition of the vital nature of our electronic images for patient care, we are now recording electronic images in two copies on disparate media. The image database is critical to both continued operations and recovery. Restoration of the database from periodic tape backups with a 24-hour cycle time may not support our clinical scenario: acquisition modalities have a limited local storage capacity, some of which will not contain the daily workload. Restoration of the database from the archived media is an exceedingly slow process, that will likely not meet our requirement to restore clinical operations without significant delay. Our PACS vendor is working on concurrent image databases that would be capable of nearly immediate switchover and recovery.

Performance evaluation of computed radiography systems.

Recommended methods to test the performance of computed radiography (CR) digital radiographic systems have been recently developed by the AAPM Task Group No. 10. Included are tests for dark noise, uniformity, exposure response, laser beam function, spatial resolution, low-contrast resolution, spatial accuracy, erasure thoroughness, and throughput. The recommendations may be used for acceptance testing of new CR devices as well as routine performance evaluation checks of devices in clinical use. The purpose of this short communication is to provide a tabular summary of the tests recommended by the AAPM Task Group, delineate the technical aspects of the tests, suggest quantitative measures of the performance results, and recommend uniform quantitative criteria for the satisfactory performance of CR devices. The applicability of the acceptance criteria is verified by tests performed on CR systems in clinical use at five different institutions. This paper further clarifies the recommendations with respect to the beam filtration to be used for exposure calibration of the system, and the calibration of automatic exposure control systems.

Urban-rural differences in total hip replacements: the next stage.

BACKGROUND: The aim of this study was to explore the differences in the incidence of primary elective total hip replacements between urban and rural communities and different age and sex groups in Northern Ireland, and to use this information to develop an equitable method for the allocation of surgical capacity among groups of general practices, in a system where referrals are matched to the contracted capacity. METHODS: A retrospective review was performed of all cases of primary elective total hip replacement between 1 April 1994 and 31 March 1997. Incidence rates were calculated using direct standardization. Age, sex, and urban and rural specific rates for Northern Ireland were calculated and applied to each general practice population giving that practice's annual expected number of total hip replacements. RESULTS: A total of 4,147 cases were analysed. The age and sex standardized incidence of primary elective total hip replacement for the total population was 87.6 per 100,000. The incidence was significantly greater in rural populations (101.3 per 100,000), than in urban ones (77.6 per 100,000), p < 0.001. The overall standardized ratio of males to females was 1:1 although it was 1:1.2 in urban and 1:0.9 in rural populations. Using a 3 year commissioning cycle, commissioning for a population of 130,000 allows a 10 per cent margin of error in the numbers of procedures required. CONCLUSIONS: A system of calculating the expected need for a total hip replacements was developed based on the demography and rurality of individual general practices. This system allowed a method of commissioning to be instituted that could significantly reduce in-patient waiting lists for this procedure.

Glaucoma in optometric practice: a survey of optometrists.

AIMS/BACKGROUND: With the ageing population, numbers of glaucoma patients are an increasing problem in ophthalmic outpatient clinics. A postal questionnaire survey was carried out in Northern Ireland with the aim of finding out how well placed optometrists are to become involved in the monitoring of glaucoma. RESULTS: Of the 171 practices surveyed, 68% of the senior practitioners responded. One practice was without a tonometer and one practice was without visual field instrumentation. Age criteria were used by 95% of practitioners for measuring intraocular pressure (IOP) and 82% used appropriate selection criteria for visual field testing. An IOP of 25 or 26 mmHg was used by 45% of practitioners as the level for referral if there are no risk factors; 89% would refer at any level if a visual field defect and disc cupping were present. CONCLUSION: The results confirm that the majority of optometrists are well equipped for the screening of glaucoma. However a significant investment in training and equipment would be required if any sort of shared care scheme were to be introduced.

Neonatal hypernatremic dehydration associated with breast-feeding malnutrition: a retrospective survey.

BACKGROUND: Hypernatremic dehydration in neonates is a potentially devastating condition. Recent reports have identified breast-feeding malnutrition as a key factor in its pathophysiology. METHODS: Using a theoretical framework for breast-feeding kinetics, a retrospective chart review of all neonates less than 28 days of age who were seen at either British Columbia's Children's Hospital or the Vancouver Breastfeeding Centre between 1991-1994 was conducted to identify and classify possible causes of breast-feeding malnutrition among neonates who developed hypernatremic dehydration. RESULTS: Twenty-one cases hypernatremic dehydration were identified. Infant weight loss ranged from 8% to 30% of birth weight, and serum sodium levels ranged from 146 mmol/L to 207 mmol/L. In each case, maternal or infant factors (e.g., poor breast-feeding technique, lactation failure following postpartum hemorrhage and infant suckling disorders associated with cleft palate or ankyloglossia) that could interfere with either lactation or breast-feeding dynamics and account for insufficient breast milk intake were identified. INTERPRETATION: Prenatal and in-hospital screening for maternal and infant risk factors for breast-feeding malnutrition combined with early postpartum follow-up to detect excessive infant weight loss are important for the prevention of neonatal hypernatremic dehydration.

Characterization of monochrome CRT display systems in the field.

This article presents a review of image quality assessment methods for monochrome CRTs in the field as opposed to the laboratory. The review includes image quality programs at the University of Washington, the University of Texas at Houston, the University of Michigan, and the University of Arizona. CRT manufacturers and display-board suppliers also are concerned with image quality, particularly with respect to the life time of the CRT. The programs show that the need for image quality assessment for CRTs in the clinic is recognized. Although several experimental programs are in place, there is no universally accepted program. In fact, the clinical consequences of degraded monitor performance are not even well known and must be established. The existing programs mainly are based on the most comprehensive test pattern, the SMPTE pattern. The programs permit assessment of maximum luminance, display function, dynamic range, and contrast. They do not permit assessment of spatial resolution. There is no easy method to determine the spatial resolution in the field as precisely as desired simply because there are no visual aids (test patterns) to reliably determine loss of spatial resolution and signal-to-noise ratio using human observers. This report also presents initial and encouraging data obtained at the University of Arizona with a CCD camera. This CCD camera has the potential to be developed into an important tool for practical CRT evaluation for the clinic.

Locations for renal services--patient satisfaction surveys.

Renal services have been given priority in recent years in an attempt to align them with levels of provision in other European countries. A survey of patients receiving renal replacement therapy in the Northern Ireland Regional Centre, Belfast, was carried out to ascertain their views on services (survey I). After the establishment of a Northern Health and Social Services Board (NHSSB) sub-regional unit in 1995, the survey was repeated for patients attending the new unit (survey II). In survey I, 53% NHSSB patients responded. Travelling time to and from hospital was a major issue for the majority of patients, with 33% of haemodialysis patients receiving twice weekly treatment unwilling to attend more frequently, even if clinically advised to do so. In survey II, 60% of patients responded. Travel times to the sub-regional unit were significantly shorter and patients felt it provided a similar or better standard of service, compared with the regional centre. All the twice weekly haemodialysis patients would increase to thrice weekly if clinically advised to do so. The study underlines the importance of locating dialysis facilities closer to patients' homes.

Casualties of the sun.

A retrospective review was carried out of all sunburn related attendances, during the periods 1/6/94-31/8/94 and 1/6/95-31/8/95, at the four A&E departments and at one of the general practices within the Northern Health and Social Services Board area. Four hundred and thirty patients had attended. The modal age group was 16-30 years. More males presented than females. Within the sexes more males presented in the under 16 years and over 30 years age group, while females were more common in the 16-30 years age group. There was documentation of blisters in 30% of patients. Those with blisters were more likely to be under 16 years and male. In females the most and least commonly affected areas correlated with the most and least commonly affected areas for cutaneous malignant melanoma. In these days of limited resources it is important to use epidemiological data such as this in order to contribute to the development of health promotion programmes and campaigns.

Staphylococcus aureus and sore nipples.

OBJECTIVE: To correlate clinical symptoms and signs of sore nipples with the presence of Staphylococcus aureus and to determine the probability of mothers having S aureus-infected nipples when these local symptoms and signs are found. DESIGN: Two cohorts of consecutive patients were enrolled regardless of presenting complaint. A questionnaire was administered to determine the presence and severity of sore nipples. Objective findings on breast examination were documented. A nipple swab was taken for culture and sensitivity. SETTING: Breastfeeding clinic serving patients referred by family physicians, pediatricians, and community health nurses. PATIENTS: A sample of 227 breastfeeding mothers was collected in two cohorts. MAIN OUTCOME MEASURES: Answers to questions about sore nipples, objective findings from physical examination, and results from nipple swabs. RESULTS: Most subjects (51%) had sore nipples, and 45% of subjects had objective findings on examination; 23% of subjects had a positive nipple swab culture; 15% grew S aureus on culture. The risk of having S aureus colonization was 4.8 times greater if nipple pain was moderate or severe rather than mild. A break in nipple integument associated with cracks, fissures, ulcers, or pus gave a 35% chance of having S aureus colonization, five times greater than when the integument was intact. CONCLUSIONS: The study showed that mothers with infants younger than 1 month who complained of moderate to severe nipple pain and who had cracks, fissures, ulcers, or exudates had a 64% chance of having positive skin cultures and a 54% chance of having S aureus colonization.

Infant insufficient milk syndrome associated with maternal postpartum hemorrhage.

Insufficient milk syndrome is defined as failure to thrive in infants due to insufficient daily breastmilk intake. This discussion examines a possible association between insufficient milk syndrome and maternal postpartum hemorrhage. Ten consecutive cases of insufficient milk syndrome associated with maternal postpartum hemorrhage were identified. The mothers presented between 3 and 35 days postpartum. Maternal postpartum blood loss ranged from 500-1500 ml in eight cases (mean: 963 ml); in two cases, blood loss was noted as 400++ and 200++, respectively. Six mothers experienced a drop of hemoglobin by > 30g/L; two had a drop in blood pressure > 30mmHg for > 20 minutes. All infants were failing to thrive. Five infants suffered hypernatremic dehydration with serum sodium levels ranging from 148-166mmol/L. Breastmilk electrolytes were measured in six cases, and elevated sodium levels, ranging from 21-100mmol/L, in five cases. These data serve to heighten awareness of insufficient milk syndrome as a potential consequence of postpartum hemorrhage. Early postpartum review of all breastfeeding mothers and infants is strongly encouraged.

Preliminary assessment of computed tomography and satellite teleradiology from Operation Desert Storm.

Computed tomography at military transportable hospitals was used for the first time during the recent Operation Desert Storm in the Saudi Arabian desert. Scan quality was excellent and the scans proved clinically important in patient management. A teleradiology link via satellite to the U.S. mainland was also successfully employed. The objectives of the teleradiology link were to validate the concept distant interpretation of images obtained on the battlefield and to provide specialty radiology consultation. This technology shows great promise for future applications, both for combat casualty care and for civilian disaster medical support operations.

Logistic representation of the sensitometric response of screen-film systems: empirical validation.

An empirical logistic model that linearizes the sensitometric response data of screen-film systems over the entire dynamic range of exposures is presented. This linearization is evident when the net optical densities are scaled as fractions of the net saturation density and plotted on commercial logit, probit, or double-log paper, except under conditions of reciprocity law failure. Weighted linear regression analysis shows that the intercept, but not the slope, depends on the screen-film system used. Previous work indicates that the slope is also independent of development time and photon energy. The model is verified through an analysis of tabulated sensitometric data published by the Center for Devices and Radiological Health.

An equation for DNA electrophoretic mobility in agarose gels.

Assignment of molecular weight to DNA fragments on the basis of electrophoretic mobility in agarose gels is complicated by nonlinearity of the relationship between mobility and molecular weight. Graphical methods that linearize sigmoidal curves provide a simplified description of the mobility function when applied to normalized mobility data. This description is valid over a wide range of molecular weights. Linear duplex molecules of lengths ranging from 118 to 169,200 base pairs were electrophoresed at voltage gradients of 1 to 6 V/cm through horizontal slab gels ranging from 0.2 to 1.6% agarose. A logit transformation of the mobility graphed versus the logarithm of molecular weight, analogous to a Hill plot of enzyme kinetics, is a straight line. Changes in the voltage gradient or gel composition alter the position but not the slope or linearity of the data plotted by this method. The logistic representation is compared with the conventional graph of log molecular weight versus mobility, with the graph of molecular weight versus reciprocal mobility, and with Probit analysis of the mobility function. Parameters were determined for one equation that accurately describes DNA mobility as a function of the three tested variables. Curves are presented that are useful in predicting fragment length, migration, resolution, and gel performance.

The role of calcium in the regulation of prostacyclin synthesis by porcine aortic endothelial cells.

Both bradykinin (EC50 = 8 ng/ml) and the ionophore A23187 (EC50 = 3 X 10(-7) M) potently stimulated arachidonate release and prostaglandin synthesis in porcine aortic endothelial cells. The response to each was completely dependent on extracellular Ca2+ (EC50 = 3 X 10(-7) M); no role for intracellular Ca2+ was noted. The rapid Ca2+ influx prompted by either activator was consistent with the time course for arachidonate release. Whereas the arachidonate released in response to bradykinin was transient, that released in response to A23187 was more prolonged, and paralleled a continued influx of Ca2+. Ca2+ entry elicited by bradykinin was mediated by channels which could not be blocked by verapamil. When Mn2+ was substituted for Ca2+, no stimulation of prostacyclin synthesis was seen in response to A23187; however, the bradykinin response was unaffected. The mechanism of these effects was studied using doses of bradykinin or A23187 which resulted in increases in Ca2+ influx and prostacyclin synthesis of similar magnitude for each agonist. Under these conditions, trifluoperazine blocked elevated prostacyclin synthesis (ID50 = 5-6 X 10(-6) M for each agonist). Trifluoperazine sulfoxide, however, was much less active. Pimozide inhibited bradykinin-stimulated prostacyclin synthesis at low doses (ID50 = 3 X 10(-6) M). Trifluoperazine was much less effective against high doses of A23187 (4 X 10(-6) M). These data suggest that arachidonate release and prostacyclin synthesis are dependent on influx of extracellular calcium and subsequent activation of a Ca2+-dependent phospholipase by a calmodulin-mediated mechanism.