Background
The Glasgow Benefit Inventory (GBI) is a validated, generic patient‐recorded outcome measure widely used in otolaryngology to report change in quality of life post‐intervention.
Objectives ...of review
To date, no systematic review has made (i) a quality assessment of reporting of Glasgow Benefit Inventory outcomes; (ii) a comparison between Glasgow Benefit Inventory outcomes for different interventions and objectives; (iii) an evaluation of subscales in describing the area of benefit; (iv) commented on its value in clinical practice and research.
Type of review
Systematic review.
Search strategy
‘Glasgow Benefit Inventory’ and ‘GBI’ were used as keywords to search for published, unpublished and ongoing trials in PubMed, EMBASE, CINAHL and Google in addition to an ISI citation search for the original validating Glasgow Benefit Inventory paper between 1996 and January 2015.
Evaluation method
Papers were assessed for study type and quality graded by a predesigned scale, by two authors independently. Papers with sufficient quality Glasgow Benefit Inventory data were identified for statistical comparisons. Papers with <50% follow‐up were excluded.
Results
A total of 118 eligible papers were identified for inclusion. A national audit paper (n = 4325) showed that the Glasgow Benefit Inventory gave a range of scores across the specialty, being greater for surgical intervention than medical intervention or ‘reassurance’. Fourteen papers compared one form of surgery versus another form of surgery. In all but one study, there was no difference between the Glasgow Benefit Inventory scores (or of any other outcome). The most likely reason was lack of power. Two papers took an epidemiological approach and used the Glasgow Benefit Inventory scores to predict benefit. One was for tonsillectomy where duration of sore throat episodes and days with fever were identified on multivariate analysis to predict benefit albeit the precision was low. However, the traditional factor of number of episodes of sore throat was not predictive. The other was surgery for chronic rhinosinusitis where those with polyps on univariate analysis had greater benefit than those without. Forty‐three papers had a response rate of >50% and gave sufficient Glasgow Benefit Inventory total and subscales for meta‐analysis. For five of the 11 operation categories (vestibular schwannoma, tonsillectomy, cochlear implant, middle ear implant and stapes surgery) that were most likely to have a single clear clinical objective, score data had low‐to‐moderate heterogeneity. The value in the Glasgow Benefit Inventory having both positive and negative scores was shown by an overall negative score for the management of vestibular schwannoma. The other six operations gave considerable heterogeneity with rhinoplasty and septoplasty giving the greatest percentages (98% and 99%) most likely because of the considerable variations in patient selection. The data from these operations should not be used for comparative purposes. Five papers also reported the number of patients that had no or negative benefit, a potentially a more clinically useful outcome to report. Glasgow Benefit Inventory subscores for tonsillectomy were significantly different from ear surgery suggesting different areas of benefit
Conclusions
The Glasgow Benefit Inventory has been shown to differentiate the benefit between surgical and medical otolaryngology interventions as well as ‘reassurance’. Reporting benefit as percentages with negative, no and positive benefit would enable better comparisons between different interventions with varying objectives and pathology. This could also allow easier evaluation of factors that predict benefit. Meta‐analysis data are now available for comparison purposes for vestibular schwannoma, tonsillectomy, cochlear implant, middle ear implant and stapes surgery. Fuller report of the Glasgow Benefit Inventory outcomes for non‐surgical otolaryngology interventions is encouraged.
Simulation of power converters has traditionally been carried out using simplified models to shorten simulation time. This will compromise the accuracy of the results. A proposed fast simulation ...method for simulating converter losses and device temperatures over long mission profiles (load cycles) is described in this paper. It utilizes accurate physics-based models for the device losses, and is validated with experimentally obtained results.
This paper describes the development and implementation of an analytical 3-D thermal model for fast and accurate thermal simulation of power device modules in electrothermal converter simulation. A ...Fourier-based solution is used to solve the 3-D heat equation. The solution can describe the variation of temperature through the whole inverter power module structure as a function of time. The model can simulate thermal interactions resulting from multiple heat sources. The thermal model is extremely fast to simulate compared to finite-element (FEM) approaches. The new model has been implemented in MATLAB/Simulink in order to cosimulate with the converter model which is in the same form. The model has been validated against the computational fluid dynamics (CFD) software package FLOTHERM and shows good agreement. The required aspects of 3-D heat diffusion are captured successfully by the Fourier-based model.
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•Most liquid NMR samples in most experiments convect.•Horizontal temperature gradients cause convection with no critical lower limit.•Attempts at sample temperature control tend to ...increase, not decrease, convection.•Convection rates can be reduced by reducing sample tube inner diameter.•Sapphire tubes greatly reduce convection under normal conditions.
Many NMR experiments on liquids suffer if the sample convects. This is particularly true for applications, such as the measurement of diffusion, that rely on spatial labelling of spins. It is widely assumed that, in most well-conducted experiments with stable temperature regulation, samples do not convect. Unfortunately this is not the case. It is shown here that typical NMR samples show measurable convective flow for all but a very narrow range of temperatures; convection is seen both above and below this range, which can be as small as a degree or so for a mobile solvent such as chloroform. This convection is driven by both vertical and horizontal temperature gradients.
Measurements of convection velocity are presented for a range of samples, sample tubes, probes, and temperatures. Both decreasing sample tube inner diameter and changing sample tube material from glass to sapphire can slow convection markedly, with sapphire tubes being particularly effective. Such tubes are likely to be particularly helpful for accurate measurement of diffusion by NMR.
To determine whether oral prednisolone or aciclovir, used separately or in combination, early in the course of Bell's palsy, improves the chances of recovery at 3 and 9 months.
A 2 x 2 factorial ...randomised double-blind trial. Patients were randomly assigned to treatment by an automated telephone service using a permuted block randomisation technique with block sizes of four or eight, and no stratification.
Mainland Scotland, with referrals mainly from general practice to 17 hospital trial sites.
Adults (aged 16 years or older) with unilateral facial nerve weakness of no identifiable cause presenting to primary care, the emergency department or NHS24 within 72 hours of symptom onset.
Patients were randomised to receive active preparations or placebo for 10 days: (1) prednisolone (50 mg per day, 2 x 25-mg capsules) and aciclovir (2000 mg per day, 5 x 400-mg capsules); (2) prednisolone and placebo (lactose, indistinguishable); (3) aciclovir and placebo; and (4) placebo and placebo.
The primary outcome was recovery of facial function assessed by the House-Brackmann scale. Secondary outcomes included health status, pain, self-perceived appearance and cost-effectiveness.
Final outcomes were available for 496 patients, balanced for gender; mean age 44 years; initial facial paralysis moderate to severe. One half of patients initiated treatment within 24 hours of onset of symptoms, one-third within 24-48 hours and the remainder within 48-72 hours. Of the completed patients, 357 had recovered by 3 months and 80 at 9 months, leaving 59 with a residual deficit. There were significant differences in complete recovery at 3 months between the prednisolone comparison groups (83.0% for prednisolone, 63.6% for no prednisolone, a difference of + 19.4%; 95% confidence interval (CI): + 11.7% to + 27.1%, p < 0.001). The number needed to treat (NNT) in order to achieve one additional complete recovery was 6 (95% CI: 4 to 9). There was no significant difference between the aciclovir comparison groups (71.2% for aciclovir and 75.7% for no aciclovir). Nine-month assessments of patients recovered were 94.4% for prednisolone compared with 81.6% for no prednisolone, a difference of + 12.8% (95% CI: + 7.2% to + 18.4%, p < 0.001); the NNT was 8 (95% CI: 6 to 14). Proportions recovered at 9 months were 85.4% for aciclovir and 90.8% for no aciclovir, a difference of -5.3%. There was no significant prednisolone-aciclovir interaction at 3 months or at 9 months. Outcome differences by individual treatment (the four-arm model) showed significant differences. At 3 months the recovery rate was 86.3% in the prednisolone treatment group, 79.7% in the aciclovir-prednisolone group, 64.7% in the placebo group and 62.5% in the aciclovir group. At 9 months the recovery rates were respectively 96.1%, 92.7%, 85.3% and 78.1%. The increase in recovery rate conferred by the addition of prednisolone (both for prednisolone over placebo and for aciclovir-prednisolone over aciclovir) is highly statistically significant (p < 0.001). There were no significant differences in secondary measures apart from Health Utilities Index Mark 3 (HUI3) at 9 months in those treated with prednisolone.
This study provided robust evidence to support the early use of oral prednisolone in Bell's palsy as an effective treatment which may be considered cost-effective. Treatment with aciclovir, either alone or with steroids, had no effect on outcome.
Clin. Otolaryngol. 2012, 37, 35–43
Objective: An assessment of the effect of otolaryngological management on the health‐related quality of life of patients.
Design: Application of the Health ...Utilities Index mark 3 (HUI‐3) before and after treatment; application of the Glasgow Benefit Inventory (GBI) after treatment.
Setting: Six otolaryngological departments around Scotland.
Participants: A 9005 adult patients referred to outpatient clinics.
Main outcome measures: Complete HUI‐3 data was collected from 4422 patients; complete GBI data from 4235; complete HUI‐3 and GBI data from 3884.
Results: The overall change in health related quality of life from before to after management was just +0.02. In the majority of subgroups of data (classified by type of management) there was essentially no change in HUI‐3 score. The major exceptions were those patients provided with a hearing aid (mean change 0.08) and those whose problem was managed surgically (mean change 0.04). The mean GBI score was 5.3 which is low. Those managed surgically reported a higher GBI score of 13.0.
Conclusion: We found that patients treated surgically or given a hearing aid reported a significant improvement in their health related quality of life after treatment in otolaryngology departments. In general, patients treated in other ways reported no significant improvement. We argue that future research should look carefully at patient groups where there is unexpectedly little benefit from current treatment methods and consider more effective methods of management.
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