Biomedical subjects

N Donaldson

Publications and source records attributed to N Donaldson.

At least 19 recordsLinked to original sources

PubMed2006

The effect of noninvasive ventilation on ALS patients and their caregivers.

BACKGROUND: Noninvasive ventilation (NIV) reduces mortality and improves some aspects of quality of life (QoL) in ALS. However, concerns remain that progressive disability may negate these benefits and unnecessarily burden caregivers. METHODS: Thirty-nine patients requiring NIV were offered treatment. Twenty-six were established on NIV, but 13 declined or could not tolerate NIV. Fifteen patients without respiratory muscle weakness (RMW) but with similar ALS severity and age were studied in parallel. Caregivers of 21 NIV, 7 untreated, and 10 patients without RMW participated. Patients and caregivers had detailed QoL measurements for 12 months. NIV patients underwent cognitive testing before and after treatment. RESULTS: RMW correlated with lower QoL. The median survival of untreated patients (18 days; 95% CI 11 to 25 days) was shorter than for NIV patients (298 days; 95% CI 192 to 404 days) and non-RMW patients (370 days; 95% CI 278 to 462 days; log rank test [2 df] = 81, p = 0.00001). A wide range of QoL measures improved within 1 month of starting NIV, and improvements were maintained for 12 months. QoL of non-RMW patients declined as RMW progressed. Caregivers of NIV and non-RMW patients showed similar increases in burden, but NIV patient caregivers developed a deterioration in the Short Form-36 Vitality score. No improvements were found on measures of learning and recall in the NIV patients. CONCLUSIONS: Respiratory muscle weakness has a greater impact on quality of life (QoL) than overall ALS severity. Noninvasive ventilation (NIV) improves QoL despite ALS progression. NIV has no impact on most aspects of caregiver QoL and does not significantly increase caregiver burden or stress.

Adult↗

PubMed2005

Noise from implantable Cooper cable.

Cooper cable is made for implanted devices, usually for connection to stimulating electrodes. An experiment has been performed to see whether these cables would be satisfactory for recording electroneurogram (ENG) signals from cuffs. Four cables were subjected to continuous flexion at 2 Hz while submerged in saline. The cables were connected to a low-noise amplifier, and the noise was measured using a spectrum analyser. These cables had not fractured after 184 million flexions, and the noise in the neural band (500-5000 Hz) had not increased owing to age. Noise in the ENG band increased by less than 3 dB owing to the motion. A fifth, worn cable did fail during the experiment, the conductors becoming exposed to the saline, but this was only apparent by extra noise when the cable was in motion. After 184 million flexions, the four cables were given a more severe test: instead of being connected to the amplifier reference node, two of the four cores of each cable were connected to 18V batteries. Two of the cables were then noisier, but only when in motion, presumably because of leakage between cores. Cooper cables are excellent for transmitting neural signals alone; transmission in one cable of neural signals and power supplies should be avoided if possible.

Electricity↗

PubMed2005

A randomised controlled comparison of alternative strategies in stroke care.

OBJECTIVES: To compare outcomes between stroke patients managed on the stroke unit, on general wards with stroke team support or at home by specialist domiciliary team and to derive prognostic variables that will identify patients most suitable for management by each strategy. To describe organisational aspects of individual strategies of stroke care and to evaluate cost-effectiveness of each strategy and its acceptability to patients, carers and professionals. DESIGN: Prospective single-blind randomised controlled trial undertaken in patients recruited from a community-based stroke register. SETTING: Suburban district in south-east England. PARTICIPANTS: Patients with disabling stroke who could be supported at home. INTERVENTIONS: The stroke unit gave 24-hour care provided by specialist multidisciplinary team based on clear guidelines for acute care, prevention of complications, rehabilitation and secondary prevention. The stroke team provided management on general wards with specialist team support. The team undertook stroke assessments and advised ward-based nursing and therapy staff on acute care, secondary prevention and rehabilitation aspects. Domiciliary care involved management at home under the supervision of a GP and stroke specialist with support from specialist team and community services. Support was provided for a maximum of 3 months. MAIN OUTCOME MEASURES: The primary measure was death or institutionalisation at 1 year. Secondary measures were dependence, functional abilities, mood, quality of life, resource use, length of hospital stay, and patient, carer and professional satisfaction. RESULTS: Of the 457 patients randomised, 152 patients were allocated to the stroke unit; 152 patients to stroke team and 153 patients to domiciliary stroke care (average age 76 years, 48% women). The groups were well matched for baseline characteristics, stroke type and severity, level of impairment and initial disability. Fifty-one (34%) patients in the domiciliary group were admitted to hospital after randomisation. Mortality and institutionalisation at 1 year were lower on stroke unit compared with stroke team or domiciliary care. Significantly fewer patients on the stroke unit died compared with those managed by the stroke team. The proportion of patients alive without severe disability at 1 year was also significantly higher on the stroke unit compared with stroke team or domiciliary care. These differences were present at 3 and 6 months after stroke. Stroke survivors managed on the stroke unit showed greater improvement on basic activities of daily living compared with other strategies. Achievement of higher levels of function was not influenced by strategy of care. Quality of life at 3 months was significantly better in stroke unit and domiciliary care patients. There was greater dissatisfaction with care on general wards compared with stroke unit or domiciliary care. Poor outcome with domiciliary care and on general wards was associated with Barthel Index <5, incontinence and, on general wards, age over 75 years. The total costs of stroke per patient over the 12-month period were pound 11,450 for stroke unit, pound 9527 for stroke team and pound 6840 for home care. However, the mean costs per day alive for the stroke unit were significantly less than those for the specialist stroke team patients, but no different from domiciliary care patients. Costs for the domiciliary group were significantly less than for those managed by the specialist stroke team on general wards. CONCLUSIONS: Stroke units were found to be more effective than a specialist stroke team or specialist domiciliary care in reducing mortality, institutionalisation and dependence after stroke. A role for specialist domiciliary services for acute stroke is not supported by this study. Management of patients with strokes on general medical wards, even with specialist team input, is not supported by this study. The stroke unit intervention was less costly per patient day alive and more effective than the stroke team intervention. The stroke unit was more effective and of equivalent cost when compared to home care. Hence, the stroke unit is a more cost-effective intervention than either stroke team or home care. Further research is needed to understand processes contributing to the reduction in mortality on stroke units and to determine the generalisability of these results and the factors that will influence the implementation of the findings of this study in clinical practice.

Activities of Daily Living↗

PubMed2004

Multiple-electrode nerve cuffs for low-velocity and velocity-selective neural recording.

In the paper, a method using multiple-electrode nerve cuffs is presented that enables electroneurographic signals (ENG) to be recorded selectively by action potential velocity. The theory uses a one-dimensional model of the electrodes in the cuff. Using this model, the transfer function for a single tripole is derived, and it is shown that more than one tripole signal can be recorded from within a cuff. When many tripole signals are available and are temporally aligned by artificial delays and summed, there is a significant increase in the amplitude of the recorded action potential, depending on the cuff length and the action potential velocity, with the greatest gain occurring for low velocities. For example, a cuff was considered that was constrained by surgical considerations to 30 mm between the end electrodes. For action potentials with a velocity of 120 m s(-1), it was shown that, as the number of tripoles increased from one, the peak energy spectral density of the recorded output increased by a factor of about 1.6 with three tripoles, whereas, for 20 m s(-1), the increase was about 19, with ten tripoles. The time delays and summation act as a velocity-selective filter. With consideration of the energy spectral densities at frequencies where these are maximum (to give the best signal-to-noise ratio), the tuning curves are presented for these velocity-selective filters and show that useful velocity resolution is possible using this method. For a 30 mm cuff with nine tripoles, it is demonstrated that it is possible to resolve at least five distinct velocity bands in the range 20-120m s(-1).

Action Potentials↗

PubMed2004

Experimental determination of compound action potential direction and propagation velocity from multi-electrode nerve cuffs.

Information extracted from whole-nerve electroneurograms, recorded using electrode cuffs, can provide signals to neuroprostheses. However, the amount of information that can be extracted from a single tripole is limited. This communication demonstrates how previously unavailable information about the direction of action potential propagation and velocity can be obtained using a multi-electrode cuff and that the arrangement acts as a velocity-selective filter. Results from in vitro experiments on frog nerves are presented.

Action Potentials↗

PubMed2004

Effect of salmeterol on respiratory muscle activity during exercise in poorly reversible COPD.

BACKGROUND: Some patients with irreversible chronic obstructive pulmonary disease (COPD) experience subjective benefit from long acting bronchodilators without change in forced expiratory volume in 1 second (FEV(1)). Dynamic hyperinflation is an important determinant of exercise induced dyspnoea in COPD. We hypothesised that long acting bronchodilators improve symptoms by reducing dynamic hyperinflation and work of breathing, as measured by respiratory muscle pressure-time products. METHODS: Sixteen patients with "irreversible" COPD (<10% improvement in FEV(1) following a bronchodilator challenge; mean FEV(1) 31.1% predicted) were recruited into a randomised, double blind, placebo controlled, crossover study of salmeterol (50 micro g twice a day). Treatment periods were of 2 weeks duration with a 2 week washout period. Primary outcome measures were end exercise isotime transdiaphragmatic pressure-time product and dynamic hyperinflation as measured by inspiratory capacity. RESULTS: Salmeterol significantly reduced the transdiaphragmatic pressure-time product (294.5 v 348.6 cm H(2)O/s/min; p = 0.03), dynamic hyperinflation (0.22 v 0.33 litres; p = 0.002), and Borg scores during endurance treadmill walk (3.78 v 4.62; p = 0.02). There was no significant change in exercise endurance time. Improvements in isotime Borg score were significantly correlated to changes in tidal volume/oesophageal pressure swings, end expiratory lung volume, and inspiratory capacity, but not pressure-time products. CONCLUSIONS: Despite apparent "non-reversibility" in spirometric parameters, long acting bronchodilators can cause both symptomatic and physiological improvement during exercise in severe COPD.

Aged↗

PubMed2004

Phentolamine re-dosing during penile dynamic colour Doppler ultrasound: a practical method to abolish a false diagnosis of venous leakage in patients with erectile dysfunction.

Increased sympathetic tone may cause an equivocal response to a prostaglandin E1 (PGE1) penile Doppler ultrasound (US) examination interpreted as a venous leak. We evaluated the US parameters and erectile response to the addition of phentolamine to a PGE1 penile Doppler US examination to ascertain whether addition of phentolamine would abolish a suboptimal response. 32 patients (median age 29 years, range 17-70 years) with either a previous Doppler US pattern of venous leakage or a clinical suspicion of venogenic impotence, underwent Doppler US after a total dose of 20 microg of PGE1. Peak systolic velocity (PSV), end diastolic velocity (EDV) and grade of erection were documented. If erectile response was suboptimal irrespective of the EDV measurement, 2 mg-intracavernosal phentolamine was administered and measurements repeated. Six patients had a normal erectile response, the remaining 26 received phentolamine. A significant increase in PSV between baseline and 20 microg PGE1 (p<0.001) was observed in all cases. Following phentolamine there was a significant increase in grade of erection (p=0.0001) and a significant reduction in the EDV (p=0.0001). A reduction of the EDV to below 0.0 cm s(-1) was observed in 16 patients. Four patients with EDV <5.0 cm s(-1) but >0.0 cm s(-1) had improved erectile response following phentolamine while six showed persistent EDV elevation >5 cm s(-1). No priapism was documented. It is essential to ensure cavernosal relaxation using phentolamine before a Doppler US diagnosis of venous leak is made. This two-stage assessment will allow this to be done efficiently and with a low risk of priapism.

Adolescent↗

PubMed2001

Can differences in management processes explain different outcomes between stroke unit and stroke-team care?

BACKGROUND: Stroke units reduce mortality and dependence, but the reasons are unclear. We have compared differences in management and complications of patients with acute stroke who were admitted to a stroke unit or to a general ward as part of a previously reported randomised trial. METHODS: 304 patients had been randomly assigned to stroke units (n=152) or to general wards supported by a specialist stroke team (152). We used a structured format to gather prospective data on the frequency of prespecified interventions in each of the major aspects of stroke care. Observations were undertaken daily for the first week and every week for the next 3 months by independent observers. The effect of differences in management on outcome at 3 months was assessed with the modified Rankin score, dichotomised to good (0-3) and poor (4-6) outcome. FINDINGS: Patients in the stroke unit were monitored more frequently (odds ratio 2.1 [1.3-3.4]) and more patients received oxygen (2.0 [1.3-3.2]), antipyretics (6.4 [1.5-27.5]), measures to reduce aspiration (6.0 [2.3-15.5]), and early nutrition (14.4 [5.1-40.9]) than those in general wards. Complications were less frequent in patients in the stroke unit than those in general wards (0.6 [0.2-0.7]), with fewer patients having progression of stroke, chest infection, or dehydration. Measures to prevent aspiration, early feeding, stroke unit management, and frequency of complications independently affected outcome. INTERPRETATION: Differences in management and complications between the stroke unit and general wards differ substantially, even when specialist support is provided. Such differences could be responsible for the more favourable outcome seen in patients on stroke units than those on general wards.

Aged↗

PubMed2001

A prospective study of quality of life in ALS patients treated with noninvasive ventilation.

Noninvasive positive pressure ventilation prolongs survival in ALS but its effect on quality of life is unknown. The authors prospectively studied quality of life using the SF-36 questionnaire in a cohort of 16 ventilated patients with ALS. Noninvasive positive pressure ventilation improved scores in the "Vitality" domain by as much as 25%, for periods of up to 15 months, despite disease progression. Noninvasive positive pressure ventilation did not cause reduced quality of life, as any fall in scores in the ventilated group were comparable to those seen in a control group. In conclusion, noninvasive positive pressure ventilation enhances quality of life when used to treat sleep-disordered breathing in patients with ALS.

Aged↗

PubMed2001

Survival patterns in biliary atresia and comparison of quality of life of long-term survivors in Japan and England.

BACKGROUND/PURPOSE: Portoenterostomy is an accepted method of achieving bile drainage in biliary atresia, but there is a paucity of data, including formal quality-of-life (QoL) studies, on long-term survivors. This report includes survival analysis and QoL studies from the world's largest series of cases treated in Japan (1951 to 1998). The Japanese QoL results are compared with a matched group of UK patients from King's College Hospital, London. METHODS: One hundred fifteen Japanese surviving portoenterostomy patients were studied and comparison of trends in survival calculated from 6-year period cohorts. Liver function and hematologic status in a group of 30 long-term survivors (14 to 24 years) were compared with 25 patients from England, (14 to 23 years). Twenty-five Japanese and 21 UK patients (SF-36) completed a QoL questionnaire. RESULTS: Median survival times in Japanese patients before 1975 were less than 1 year but increased to 18 years after 1975. Hematologic and liver function test results did not show any significant differences between the Japanese and UK patients. QoL studies in the UK patients showed no significant difference from normative, general population data. Japanese patients underperformed in general health (P = .01), role emotional (P = .05) and role physical (P = .07) but, overall, there was no significant difference between the Japanese and UK patients except for marginal differences in indices of general health and vitality (P = .06 and .04, respectively). CONCLUSIONS: Long-term survival rate in the Japanese patients increased dramatically from 1 year to 17 years after 1975. The QoL of survivors was comparable in Japan and England. The satisfactory comparison with normative population data suggests that we should continue to use portoenterostomy as the primary treatment for biliary atresia. J Pediatr Surg 36:892-897.

Adolescent↗

PubMed2001

Respiratory muscle strength and ventilatory failure in amyotrophic lateral sclerosis.

Although ventilatory failure is the most common cause of death in amyotrophic lateral sclerosis (ALS) and measurement of respiratory muscle strength (RMS) has been shown to have prognostic value, no single test of strength can predict the presence of hypercapnia reliably. RMS was measured in 81 ALS patients to evaluate the relationship between tests of RMS and the presence of ventilatory failure, defined as a carbon dioxide tension > or = 6 kPa. We studied the predictive value of vital capacity (VC), static inspiratory and expiratory mouth pressures (MIP, MEP), maximal sniff oesophageal (sniff P(oes)), transdiaphragmatic (sniff P(di)) and nasal (SNP) pressure, cough gastric (cough P(gas)) pressure and transdiaphragmatic pressure after bilateral cervical magnetic phrenic nerve stimulation (CMS P(di)) to identify the risk of ventilatory failure in the whole group and in subgroups of patients with and without significant bulbar involvement. For patients without significant bulbar involvement, sniff P(di) had greatest predictive power [odds ratio (OR) 57] with specificity, sensitivity and positive and negative predictive values (PPV, NPV) of 87, 90, 74 and 95%, respectively Of the less invasive tests, per cent predicted SNP had greater overall predictive power (OR 25, specificity 85%, sensitivity 81%) than per cent predicted VC (9, 89%, 53%) and per cent predicted MIP (6, 83%, 55%). No test had significant predictive power for the presence of hypercapnia when used to measure RMS in a subgroup of patients with significant bulbar weakness. Thirty-five patients underwent polysomnography. CMS P(di), sniff P(di) and per cent predicted SNP were significantly correlated with the apnoea/hypopnoea index (AHI) (P = 0.035, 0.042 and 0.026, respectively). The correlations between AHI and per cent predicted MIP and VC were less strong (both non-significant). In ALS patients without significant bulbar involvement, novel tests of RMS have greater predictive power than conventional tests to predict hypercapnia. In particular, the non-invasive SNP is more sensitive than VC and MIP, suggesting that it could usefully be included in tests of respiratory muscle strength in ALS and will be helpful in assessing the risk of ventilatory failure. In patients with significant bulbar involvement, tests of respiratory muscle strength do not predict hypercapnia. Sleep-disordered breathing is correlated with RMS and the novel tests of RMS having the strongest relationship with the degree of sleep disturbance.

Adult↗

PubMed2001

A response to California's mandated nursing ratios.

PURPOSE: To explore the need for evidence-based health policy, as illustrated by the mandatory staffing bill passed by the California state legislature in 1999. DESIGN: Prospective data were collected from a voluntary sample of California acute care hospital representatives to describe selected patient safety and clinical outcomes and nurse staffing variables at the patient-care unit level. METHODS: Data for descriptive analysis were collected on hospital nurse staffing, patient falls, and pressure ulcers from 257 medical, surgical, medical-surgical combined, step-down, 24-hour observation units, and critical care patient care units in 38 California acute care hospitals from June 1998 to June 1999. FINDINGS: Nursing staffing ratios varied among the 257 units. RNs provided 91% of the nursing care in critical care units. Patients in medical-surgical units received 59% of their care from RNs, 11% from licensed vocational nurses, and 30% from other caregivers. Preliminary data showed no relationships between reported staffing ratios in these hospitals and the incidence of patient falls or hospital-acquired pressure ulcers. CONCLUSIONS: California Nursing Outcomes Coalition (CalNOC) data showed wide variations in staffing ratios, patient falls, and hospital-acquired pressure ulcers among nursing units and hospitals. These early findings indicate the need for additional research before determining minimal RN staffing requirements. Analysis of multiple sources of data may be necessary to determine safe staffing ratios and to provide evidence-based data for public policy.

Accidental Falls↗

PubMed2000

Alternative strategies for stroke care: a prospective randomised controlled trial.

BACKGROUND: Organised specialist care for stroke improves outcome, but the merits of different methods of organisation are in doubt. This study compares the efficacy of stroke unit with stroke team or domiciliary care. METHODS: A single-blind, randomised, controlled trial was undertaken in 457 acute-stroke patients (average age 76 years, 48% women) randomly assigned to stroke unit, general wards with stroke team support, or domiciliary stroke care, within 72 h of stroke onset. Outcome was assessed at 3, 6, and 12 months. The primary outcome measure was death or institutionalisation at 12 months. Analyses were by intention to treat. FINDINGS: 152 patients were allocated to the stroke unit, 152 to stroke team, and 153 to domiciliary stroke care. 51 (34%) patients in the domiciliary group were admitted to hospital after randomisation. Mortality or institutionalisation at 1 year were lower in patients on a stroke unit than for those receiving care from a stroke team (21/152 [14%] vs 45/149 [30%]; p<0.001) or domiciliary care (21/152 [14%] vs 34/144 [24%]; p=0.03), mainly as a result of reduction in mortality. The proportion of patients alive without severe disability at 1 year was also significantly higher on the stroke unit compared with stroke team (129/152 [85%] vs 99/149 [66%]; p<0.001) or domiciliary care (129/152 [85%] vs 102/144 [71%]; p=0.002). These differences were present at 3 and 6 months after stroke. INTERPRETATION: Stroke units are more effective than a specialist stroke team or specialist domiciliary care in reducing mortality, institutionalisation, and dependence after stroke.

Aged↗

PubMed2000

Prospective cohort study to determine if trial efficacy of anticoagulation for stroke prevention in atrial fibrillation translates into clinical effectiveness.

OBJECTIVE: To determine whether trial efficacy of prophylaxis with warfarin for patients with atrial fibrillation at high risk of stroke translates into effectiveness in clinical practice. DESIGN: Two year prospective cohort study. SETTING: District general hospital. PARTICIPANTS: 167 patients with atrial fibrillation and at high stroke risk who were eligible for anticoagulation. INTERVENTIONS: Long term anticoagulation with warfarin at adjusted doses to maintain an international normalised ratio of 2.0-3.0. MAIN OUTCOME MEASURES: Comparison of patient characteristics, comorbidity, anticoagulation control, stroke rate, and haemorrhagic complications with pooled data from five randomised controlled trials. RESULTS: Patients in the study group were seven years older (95% confidence interval 4 to 10) and comprised 33% more women than patients in the pooled trials. The international normalised ratio was in the target range for 61% of the time (range 37%-85%), below for 26% of the time (range 8%-32%), and above for 13% of the time (range 6%-26%). The time that patients in the study group spent in the target range was significantly less than in the pooled analysis. The incidence of stroke in the study group (2.0% per year, 0.7% to 4. 4%) was comparable to that of patients receiving warfarin in pooled studies (1.4%, 0.8% to 2.3%). Per year the incidence of major (1.7% v 1.6%) and minor (5.4% v 9.2%) bleeding complications was also similar. CONCLUSION: Rates of stroke and major haemorrhage after anticoagulation in clinical practice were comparable to those obtained from pooled data from randomised controlled studies for patients with atrial fibrillation at high risk of stroke.

Aged↗

PubMed2000

Variation of recruitment nonlinearity and dynamic response of ankle plantarflexors.

The ankle plantarflexor muscles of paraplegics may be trained to provide balance without support from the hands (in the laboratory environment) with the controller based on a two-block Hammerstein muscle model. This paper presents data on the variations of the recruitment curve block and linear dynamics block with electrode position, among various individuals and with fatigue. The tests were conducted in six groups: 'a' tests of a neurologically-intact subject were repeated on one day several times to record the effect of muscle fatigue; 'b' the same individual kept electrodes attached for a week and the muscle was identified every day; 'c' the same subject attached electrodes at marked positions every day for a week prior to identification; 'd' another normal attached electrodes at notionally the same positions over a period of one week; 'e' three normals and 'f' two paraplegics. Measurements were made with the Wobbler apparatus, in which the subject is supported upright in a standing posture. When comparing tests of fresh muscle every day, little difference was found between the nonlinear recruitment curves and linear dynamics of groups 'b' and 'c'. In fatigued muscle the dynamics were slower. When the electrode position was not carefully reproduced, and over a longer period, significant differences in nonlinearity appear in the curve shapes (group 'd') and a similar amount of variation occurs between normals, between paraplegics, and from normals to paraplegics. The paraplegic curves show wider deadbands. The effect of prolonged stimulation on normals is slight but on paraplegics it is significant.

Adult↗

PubMed2000

Sequential re-analysis of a phase-III clinical trial in non-small cell lung cancer.

This paper presents a reanalysis of a randomized clinical trial conducted by the Cancer and Leukemia Group B (CALGB, Bethesda, MD, USA). This trial found a significant benefit of combination chemotherapy followed by irradiation (CTRT) in comparison to radiotherapy alone (RT) for the treatment of nonsmall cell lung cancer. The validity of the results obtained and the decision to terminate taken by the CALGB, were assessed using sequential methods. The reliability and efficiency of sequential methods were also assessed for this study. Two sequential designs were used: the triangular and the restricted procedure. Initial analyses were conducted with the data from patients actually recruited, adjusting for important prognostic variables at any interim analysis. As a confirmatory technique, a continuation of the trial was simulated, sampling extra patients under the assumption of no treatment difference, preserving the effect of the prognostic variables. Using the results from the 155 patients recruited by the CALGB (88 deaths at termination and 136 after follow-up), the sample path stayed within the continuation region of both sequential designs considered. An underpowered sequential analysis showed significant superiority of CTRT over RT (95% confidence interval (95% CI) 0.50-0.96, p=0.03 for the triangular; 95% CI 0.37-0.88, p=0.01 for the restricted procedure). Conventional analysis of the follow-up data also showed significant superiority of CTRT. The trial extended with simulated data ended at 60 months with 251 patients (178 deaths), showing significant superiority of CTRT under both designs (95% CI for hazard ratio 0.55-0.97). The two sequential procedures would have led to the same conclusion as that reached by the Cancer and Leukemia Group B, still achieving considerable savings in patients recruited and time over the conventional design. The data simulated under the rather conservative null hypothesis did not reverse the positive result claimed by the Cancer and Leukemia Group B.

Carcinoma, Non-Small-Cell Lung↗

PubMed2000

FES cycling may promote recovery of leg function after incomplete spinal cord injury.

STUDY DESIGN: Single subject pilot. OBJECTIVES: (i) To see whether strength and endurance for recreational cycling by functional electrical stimulation (FES) are possible following spinal cord injury (SCI). (ii) To develop the equipment for FES-cycling. SETTING: England. METHODS: Near-isometric or cycling exercise was performed by the incomplete SCI subject at home. RESULTS: After training for an average of 21 min per day for 16 months, the stimulated muscles increased in size and the subject was able to cycle for 12 km on the level. Surprisingly, there was a substantial increase in the measured voluntary strength of the knee extensors and the subject reports improved leg function. CONCLUSION: FES-cycling may promote recovery after incomplete spinal cord injury. If so, it offers the possibility of being a convenient method for widespread use.

Bicycling↗

PubMed2000

The effect of nerve cuff geometry on interference reduction: a study by computer modeling.

The effect of nonlinearity in the extrafascicular field in tripolar electrode cuffs on interference pick-up was investigated. It was concluded that the interference is sensitive to electrode separation, especially in short cuffs. This suggests that significant improvements can be obtained by placing the end electrodes a few mm from the cuff ends.

Computer Simulation↗