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Biomedical subjects

R Grieve

Publications and source records attributed to R Grieve.

18 recordsLinked to original sources
PubMed2001

Comparison of hypertonic saline and alternate-day or daily recombinant human deoxyribonuclease in children with cystic fibrosis: a randomised trial.

BACKGROUND: Daily recombinant human deoxyribonuclease (rhDNase) is an established but expensive treatment in cystic fibrosis. Alternate-day treatment, if equally effective, would reduce the drug cost. Hypertonic saline improved lung function to the same degree as rhDNase in short-term studies. We compared the effectiveness of daily rhDNase, hypertonic saline, and alternate-day rhDNase in children with cystic fibrosis. METHODS: In an open cross-over trial, 48 children were allocated in random order to 12 weeks of once-daily rhDNase (2.5 mg), alternate-day rhDNase (2.5 mg), and twice-daily 5 mL 7% hypertonic saline. The primary outcome was forced expiratory volume in 1 s (FEV(1)). Secondary outcomes were forced vital capacity, number of pulmonary exacerbations, weight gain, quality of life, exercise tolerance, and the total costs of hospital and community care. FINDINGS: Mean FEV(1) increased by 16% (SD 25%), 14% (22%), and 3% (21%) with daily rhDNase, alternate-day rhDNase, and hypertonic saline, respectively. There was no difference between daily and alternate-day rhDNase (2% [95% CI -4 to 9], p=0.55). However, daily rhDNase showed a significantly greater increase in FEV(1) than hypertonic saline (8% [2 to 14], p=0.01). The average difference in 12-week cost between daily and alternate-day rhDNase was pound513 (95% CI -546 to 1510) and that between daily rhDNase and hypertonic saline was pound1409 (440 to 2318). None of the secondary clinical outcomes showed significant differences between treatments. INTERPRETATION: Hypertonic saline, delivered by jet nebuliser, is not as effective as daily rhDNase, although there is variation in individual response. There is no evidence of a difference between daily and alternate-day rhDNase.

Adolescent↗
PubMed2001

The development and use of a method to compare the costs of acute stroke across Europe.

BACKGROUND: there is a need for more information on the costs of different ways of managing stroke. Methods to compare the costs of stroke care in different countries have not been previously developed. OBJECTIVE: to develop and use a method to compare the costs of acute stroke care across Europe. SETTING: acute hospitals in 13 different European centres. SUBJECTS AND METHODS: we included in the study stroke patients hospitalized during 1996-7 at 13 centres across Europe (n=2072). We recorded the duration of acute hospital stay and use of investigations. Mean costs for each centre were predicted using linear regression analysis to adjust for case-mix differences. RESULTS: the average acute hospital stay ranged from 9 days (Spain) to 35 days (UK; P < 0.001). The predicted mean cost of treating conscious, continent men aged > 74 ranged from $220 (95% confidence interval 191-254) in Latvia to $5164 (4294-6191) in Austria. CONCLUSIONS: differences in the acute costs of stroke exist across Europe because of differences in clinical practice and unit costs. This methodology will be used to capture the costs incurred by a broad range of care providers. These estimates will then be suitable for using in cost-effectiveness analysis.

Acute Disease↗
PubMed2001

A comparison of the costs and survival of hospital-admitted stroke patients across Europe.

BACKGROUND AND PURPOSE: Policy makers require evidence on the costs and outcomes of different ways of organizing stroke care. This study compared the costs and survival of different ways of providing stroke care. METHODS: Hospitalized stroke patients from 13 European centers were included, with demographic, case-mix, and resource use variables measured for each patient. Unit costs were collected and converted into US dollars using the purchasing power parity (PPP) index. Cox and linear regression analyses were used to compare survival and costs between the centers adjusting for case mix. RESULTS: A total of 1847 patients were included in the study. After case-mix adjustment, the mean predicted costs ranged from $466 [95% CI 181 to 751] in Riga (Latvia) to $8512 [7696 to 9328] in Copenhagen (Denmark), which reflected differences in unit costs, and resource use. The mean length of hospitalization ranged from 8.3 days in Menorca (Spain) to 36.8 days in Turku B (Finland). In the 3 Finnish centers at least 80% of patients were admitted to wards providing organized stroke care, which was not provided at the centers in Almada (Portugal), Menorca, or Riga. Patients in Turku A and Turku B were less likely to die than those in Riga, Warsaw (Poland), or Menorca. The adjusted hazard ratios were 0.18 [0.10 to 0.32] for Turku A, 0.18 [0.10 to 0.32] for Turku B, 0.68 [0.48 to 0.96] for Warsaw, and 0.56 [0.33 to 0.96] for Menorca, all compared with Riga. CONCLUSIONS: The cost of stroke care varies across Europe because of differences in unit costs, and resource use. Further research is needed to assess which ways of organizing stroke care are the most cost-effective.

Aged↗
PubMed2000

A comparison of the cost-effectiveness of stroke care provided in London and Copenhagen.

OBJECTIVES: This study compared the relative cost-effectiveness of stroke care provided in London and Copenhagen. METHODS: Hospitalized stroke patients at centers in London (1995-96) and Copenhagen (1994-95) were included. Each patient's use of hospital and community health services was recorded for 1 year after stroke. Center-specific unit costs were collected and converted into dollars using the Purchasing Power Parity Index. An incremental cost-effectiveness ratio (ICER) was calculated comparing a Copenhagen model of stroke care to a London model, using regression analysis to adjust for case-mix differences. RESULTS: A total of 625 patients (297 in Copenhagen, 328 in London) were included in the analysis. Most patients in London (85%) were admitted to general medical wards, with 26% subsequently transferred to a stroke unit. In Copenhagen, 57% of patients were directly admitted to a stroke or neurology unit, with 23% then transferred to a separate rehabilitation hospital. The average length of total hospital stay was 11 days longer in Copenhagen. Patients in Copenhagen were less likely to die than those in London; for patients with cerebral infarction the hazard ratio after case-mix adjustment was 0.53 (95% CI from 0.35 to 0.80). However, a lower proportion of patients with hemorrhagic stroke died in London. The ICER of using the Copenhagen compared with the London model of care ranged from $21,579 to $37,444 per life-year gained for patients with cerebral infarctions. CONCLUSIONS: The ICERs of the Copenhagen compared with the London model of care were within a range generally regarded as cost-effective.

Aged↗
PubMed2000

Nonlinear adaptive filtering of stimulus artifact.

Noninvasive measurements of somatosensory evoked potentials have both clinical and research applications. The electrical artifact which results from the stimulus is an interference which can distort the evoked signal, and introduce errors in response onset timing estimation. Given that this interference is synchronous with the evoked signal, it cannot be reduced by the conventional technique of ensemble averaging. The technique of adaptive noise cancelling has potential in this regard however, and has been used effectively in other similar problems. An adaptive noise cancelling filter which uses a neural network as the adaptive element is investigated in this application. The filter is implemented and performance determined in the cancelling of artifact for in vivo measurements on the median nerve. A technique of segmented neural network training is proposed in which the network is trained on that segment of the record time window which does not contain the evoked signal. The neural network is found to generalize well from this training to include the segment of the window containing the evoked signal. Both quantitative and qualitative measures show that significant stimulus artifact reduction is achieved.

Artifacts↗
PubMed1998

The effectiveness of parents in promoting the development of road crossing skills in young children.

BACKGROUND: Young children show poor judgment when asked to select a safe place to cross the road, frequently considering dangerous sites to be safe. Correspondingly, child pedestrian accidents are over-represented at such locations. Increasing the child's ability to recognise such dangers is a central challenge for road safety education. AIMS: Practical training methods have proved effective in improving such judgments but are labour-intensive, time-consuming and therefore difficult to implement on a realistic scale. The study examined the possibility that volunteers from the local community might be capable of using such methods to promote children's pedestrian competence. SAMPLE: Sixty children from the Primary 1 (Reception) classes of three Glasgow schools took part. Volunteers were ordinary parents from the same areas. None had 'formal' experience of working with children other than through being parents. METHOD: Volunteers received experience of training children at courses organised in each school. Children learned in small groups, receiving two sessions of roadside training followed by four on a table-top model. Pre- and post-tests allowed the effectiveness of training to be assessed. RESULTS: Significant improvements relative to controls were found in all children following training. Improvements proved robust and no deterioration was observed two months after the programme ended. Comparison with a previous study in which training was undertaken by highly qualified staff showed that the volunteers were as effective as 'expert' trainers. CONCLUSIONS: Parent volunteers can significantly increase the pedestrian competence of children as young as five years. They constitute a most valuable 'resource' in road safety education. The opportunities afforded by involving the local community in educational interventions should be further explored.

Accidents, Traffic↗
PubMed1992

Errors in young children's decisions about traffic gaps: experiments with roadside simulations.

Young children's vulnerability as pedestrians has often been attributed to deficiencies in their decision making about vehicle approach times. Some studies have found a preponderance of risky decisions below the age of eight years. In contrast, studies using a closer simulation of road crossing, known as the pretend road, have found a preponderance of overcautious decisions in young children: traffic gaps of adequate size were frequently rejected (missed opportunities). However, the pretend road has potentially distorting characteristics which may account for this divergent pattern of findings. The experiments reported below show that new simulations that eradicate distortions nevertheless validate the pattern of results produced with the pretend road. Differences between adults and young children were pronounced for missed opportunities, but not for risky decisions. Subsidiary analyses suggest that the risky decisions of the youngest children may have arisen through lapses in attention, rather than deficits in timing. These findings run contrary to the view that attributes young children's pedestrian vulnerability to perceptuo-motor deficiency.

Acceleration↗
PubMed1991

Development and dynamics of regional specialization within the syncytial epidermis of the rat tapeworm, Hymenolepis diminuta.

The epidermis of the tapeworm Hymenolepis diminuta is a highly organized syncytium, composed of an outer layer of continuous cytoplasm, or ectocytoplasm, and an inner layer of nucleated cell bodies, or perikarya. The perikarya are in direct cytoplasmic continuity with the ectocytoplasm via narrow plasmalemma-bound bridges called internuncial process. Although distinct structural and functional differences are apparent between ectocytoplasm and perikarya, all of the perikarya along the body of the cestode are morphologically similar, as are all regions of ectocytoplasm. However, immunocytochemically distinct subpopulations of perikarya and regionally defined areas of ectocytoplasm were identified along the tapeworm strobila by the use of monoclonal antibodies raised against a preparation of isolated tegument. The different types of perikarya and the regionally specialized areas of ectocytoplasm were organized in a topographically precise manner along the body of the parasite. Examination of labeling patterns after colchicine treatment suggests that different types of perikarya are specialized for biosynthesis of specific tegumental molecules and for turnover or recycling of tegumental material. Furthermore, it appears that a 52 kDa polypeptide synthesized by one population of perikarya is transported through the syncytium and ultimately resorbed by a different population of tegumental perikarya. These data suggest that the syncytial epidermis of parasitic platyhelminthes exhibits a more complex organization of function than previously appreciated.

Animals↗
PubMed1982

Mentally retarded children's abilities in the process of comparison.

Mentally retarded children were asked to make various types of comparisons between sets and subsets of objects. Results showed that they succeeded when the comparison involved numerically unequal subsets of objects within the same set. When sets, or subsets, were numerically equal, the children clearly failed; instead of rejecting both alternatives in the comparison question, they selected one. With other comparisons, within and between sets and subsets of objects, the children guessed at an answer, and there was a tendency to answer in accordance with the most recently uttered part of the comparison question. These results indicate that although retarded children are thoroughly acquainted with certain aspects of language and its use in the process of comparison, other important aspects have yet to be learned.

Adolescent↗
PubMed1978

Social and attentional aspects of echolalia in highly echolalic mentally retarded persons.

Echolalia was examined in a sample of highly echolalic mentally retarded individuals. When presented with a standard set of questions, under conditions differing in appropriateness for exchange of discourse (e.g., questions presented with examiner and patient face-to-face vs. questions presented with the examiner's face averted vs. questions addressed towards another person sitting silently beside the patient), subjects' frequency of echolalia varied. Besides showing considerable sensitivity to aspects of discourse exchange, subjects exhibited some limited capacity for processing linguistic information.

Adolescent↗