A randomised, double blind, placebo-controlled trial of a two-week course of dexamethasone for adult patients with a symptomatic Chronic Subdural Haematoma (Dex-CSDH trial)

Background

Chronic subdural haematoma is a collection of 'old blood' and its breakdown products in the subdural space and predominantly affects older people. Surgical evacuation remains the mainstay in the management of symptomatic cases.

Objective

The Dex-CSDH (DEXamethasone in Chronic SubDural Haematoma) randomised trial investigated the clinical effectiveness and cost-effectiveness of dexamethasone in patients with a symptomatic chronic subdural haematoma.

Design

This was a parallel, superiority, multicentre, pragmatic, randomised controlled trial. Assigned treatment was administered in a double-blind fashion. Outcome assessors were also blinded to treatment allocation.

Setting

Neurosurgical units in the UK.

Participants

Eligible participants included adults (aged ≥ 18 years) admitted to a neurosurgical unit with a symptomatic chronic subdural haematoma confirmed on cranial imaging.

Interventions

Participants were randomly assigned in a 1 : 1 allocation to a 2-week tapering course of dexamethasone or placebo alongside standard care.

Main outcome measures

The primary outcome was the Modified Rankin Scale score at 6 months dichotomised to a favourable (score of 0-3) or an unfavourable (score of 4-6) outcome. Secondary outcomes included the Modified Rankin Scale score at discharge and 3 months; number of chronic subdural haematoma-related surgical interventions undertaken during the index and subsequent admissions; Barthel Index and EuroQol 5-Dimension 5-Level utility index score reported at discharge, 3 months and 6 months; Glasgow Coma Scale score reported at discharge and 6 months; mortality at 30 days and 6 months; length of stay; discharge destination; and adverse events. An economic evaluation was also undertaken, during which the net monetary benefit was estimated at a willingness-to-pay threshold of £20,000 per quality-adjusted life-year.

Results

A total of 748 patients were included after randomisation: 375 were assigned to dexamethasone and 373 were assigned to placebo. The mean age of the patients was 74 years and 94% underwent evacuation of their chronic subdural haematoma during the trial period. A total of 680 patients (91%) had 6-month primary outcome data available for analysis: 339 in the placebo arm and 341 in the dexamethasone arm. On a modified intention-to-treat analysis of the full study population, there was an absolute reduction in the proportion of favourable outcomes of 6.4% (95% confidence interval 11.4% to 1.4%; p = 0.01) in the dexamethasone arm compared with the control arm at 6 months. At 3 months, the between-group difference was also in favour of placebo (-8.2%, 95% confidence interval -13.3% to -3.1%). Serious adverse events occurred in 60 out of 375 (16.0%) in the dexamethasone arm and 24 out of 373 (6.4%) in the placebo arm. The net monetary benefit of dexamethasone compared with placebo was estimated to be -£97.19.

Conclusions

This trial reports a higher rate of unfavourable outcomes at 6 months, and a higher rate of serious adverse events, in the dexamethasone arm than in the placebo arm. Dexamethasone was also not estimated to be cost-effective. Therefore, dexamethasone cannot be recommended for the treatment of chronic subdural haematoma in this population group.

Future work and limitations

A total of 94% of individuals underwent surgery, meaning that this trial does not fully define the role of dexamethasone in conservatively managed haematomas, which is a potential area for future study.

Trial registration

This trial is registered as ISRCTN80782810.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 13/15/02) and is published in full in Health Technology Assessment; Vol. 28, No. 12. See the NIHR Funding and Awards website for further award information.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

Real-time continuous glucose monitoring in preterm infants (REACT): an international, open-label, randomised controlled trial

BACKGROUND

Hyperglycaemia and hypoglycaemia are common in preterm infants and have been associated with increased risk of mortality and morbidity. Interventions to reduce risk associated with these exposures are particularly challenging due to the infrequent measurement of blood glucose concentrations, with the potential of causing more harm instead of improving outcomes for these infants. Continuous glucose monitoring (CGM) is widely used in adults and children with diabetes to improve glucose control, but has not been approved for use in neonates. The REACT trial aimed to evaluate the efficacy and safety of CGM in preterm infants requiring intensive care.

METHODS

This international, open-label, randomised controlled trial was done in 13 neonatal intensive care units in the UK, Spain, and the Netherlands. Infants were included if they were within 24 h of birth, had a birthweight of 1200 g or less, had a gestational age up to 33 weeks plus 6 days, and had parental written informed consent. Infants were randomly assigned (1:1) to real-time CGM or standard care (with masked CGM for comparison) using a central web randomisation system, stratified by recruiting centre and gestational age (<26 or ≥26 weeks). The primary efficacy outcome was the proportion of time sensor glucose concentration was 2·6-10 mmol/L for the first week of life. Safety outcomes related to hypoglycaemia (glucose concentrations <2·6 mmol/L) in the first 7 days of life. All outcomes were assessed on the basis of intention to treat in the full analysis set with available data. The study is registered with the International Standard Randomised Control Trials Registry, ISRCTN12793535.

FINDINGS

Between July 4, 2016, and Jan 27, 2019, 182 infants were enrolled, 180 of whom were randomly assigned (85 to real-time CGM, 95 to standard care). 70 infants in the real-time CGM intervention group and 85 in the standard care group had CGM data and were included in the primary analysis. Compared with infants in the standard care group, infants managed using CGM had more time in the 2·6-10 mmol/L glucose concentration target range (mean proportion of time 84% [SD 22] vs 94% [11]; adjusted mean difference 8·9% [95% CI 3·4-14·4]), equivalent to 13 h (95% CI 5-21). More infants in the standard care group were exposed to at least one episode of sensor glucose concentration of less than 2·6 mmol/L for more than 1 h than those in the intervention group (13 [15%] of 85 vs four [6%] of 70). There were no serious adverse events related to the use of the device or episodes of infection.

INTERPRETATION

Real-time CGM can reduce exposure to prolonged or severe hyperglycaemia and hypoglycaemia. Further studies using CGM are required to determine optimal glucose targets, strategies to obtain them, and the potential effect on long-term health outcomes.

FUNDING

National Institute for Health Research Efficacy and Mechanisms Evaluation Programme.

Cost-effectiveness of real time continuous glucose monitoring to target glucose control in preterm infants

The optimal management of glucose levels in critical care remains an area for research due to the problems of balancing the risks of hyperglycemia versus hypoglycemia. This paper reports the first economic evaluation of real time continuous glucose monitoring to guide the clinical management of preterm infants, based on evidence from the REACT trial. Bivariate regression of costs (£, 2016-17 prices) and cases of adequate glucose control, with multiple imputation of missing data, was conducted. When the economic evaluation was restricted to the first week of life, real time continuous glucose monitoring was associated with increased costs and a statistically significant increase in adequate glucose control. When the assessment was performed over a time horizon extending to 36 weeks' corrected gestational age, real time CGM was dominant in health economic terms, i.e. associated with lower costs and better outcomes. These results largely remained robust to a range of sensitivity analyses and sub-group analyses designed to address uncertainty and heterogeneity surrounding the cost-effectiveness outcomes. This study suggests that the use of real time continuous glucose monitoring in preterm infants is associated with a high probability of cost-effectiveness.

Trial of Dexamethasone for Chronic Subdural Hematoma

BACKGROUND

Chronic subdural hematoma is a common neurologic disorder that is especially prevalent among older people. The effect of dexamethasone on outcomes in patients with chronic subdural hematoma has not been well studied.

METHODS

We conducted a multicenter, randomized trial in the United Kingdom that enrolled adult patients with symptomatic chronic subdural hematoma. The patients were assigned in a 1:1 ratio to receive a 2-week tapering course of oral dexamethasone, starting at 8 mg twice daily, or placebo. The decision to surgically evacuate the hematoma was made by the treating clinician. The primary outcome was a score of 0 to 3, representing a favorable outcome, on the modified Rankin scale at 6 months after randomization; scores range from 0 (no symptoms) to 6 (death).

RESULTS

From August 2015 through November 2019, a total of 748 patients were included in the trial after randomization - 375 were assigned to the dexamethasone group and 373 to the placebo group. The mean age of the patients was 74 years, and 94% underwent surgery to evacuate their hematomas during the index admission; 60% in both groups had a score of 1 to 3 on the modified Rankin scale at admission. In a modified intention-to-treat analysis that excluded the patients who withdrew consent for participation in the trial or who were lost to follow-up, leaving a total of 680 patients, a favorable outcome was reported in 286 of 341 patients (83.9%) in the dexamethasone group and in 306 of 339 patients (90.3%) in the placebo group (difference, -6.4 percentage points [95% confidence interval, -11.4 to -1.4] in favor of the placebo group; P = 0.01). Among the patients with available data, repeat surgery for recurrence of the hematoma was performed in 6 of 349 patients (1.7%) in the dexamethasone group and in 25 of 350 patients (7.1%) in the placebo group. More adverse events occurred in the dexamethasone group than in the placebo group.

CONCLUSIONS

Among adults with symptomatic chronic subdural hematoma, most of whom had undergone surgery to remove their hematomas during the index admission, treatment with dexamethasone resulted in fewer favorable outcomes and more adverse events than placebo at 6 months, but fewer repeat operations were performed in the dexamethasone group. (Funded by the National Institute for Health Research Health Technology Assessment Programme; Dex-CSDH ISRCTN number, ISRCTN80782810.).

Twelve previously healthy non-geriatric dogs present for acute kidney injury after general anaesthesia for non-emergency surgical procedures in the UK

OBJECTIVES

To characterise common factors after a suspected increase in the incidence of post-procedure acute kidney injury in healthy dogs presenting for non-emergency surgical procedures.

MATERIALS AND METHODS

Retrospective analysis of the medical records of 12 dogs that presented for acute kidney injury after general anaesthesia for non-emergency surgical procedures.

RESULTS

The 12 non-geriatric dogs re-presented with acute kidney injury at a median of 4 days after surgery to four different veterinary centres, including three multidisciplinary referral practices in the UK. All dogs in this case series weighed more than 20 kg and had a median age of 17 months. There was no apparent association with breed, type of surgery, duration of anaesthesia, perioperative drug choice or non-steroidal anti-inflammatory drug administration.

CLINICAL SIGNIFICANCE

Although well-defined in human medicine, there is very little information regarding the association between general anaesthesia and acute kidney injury in animals. No definitive causal link was found in this case series. Clinicians with similar cases are requested to contact the corresponding author so a more representative incidence rate can be obtained.

Statistical analysis plan for the Dex-CSDH trial: a randomised, double-blind, placebo-controlled trial of a 2-week course of dexamethasone for adult patients with a symptomatic chronic subdural haematoma

BACKGROUND

The incidence of chronic subdural haematoma (CSDH) is increasing. Although surgery remains the mainstay of management for symptomatic patients, uncertainty remains regarding the role of steroids. Hence, the Dex-CSDH trial was launched in the UK in 2015 aiming to determine whether, compared to placebo, dexamethasone can improve the 6-month functional outcome of patients with symptomatic CSDH by reducing the rate of surgical intervention and recurrence rate.

METHODS AND DESIGN

Dex-CSDH is a multi-centre, pragmatic, parallel group, double-blind, randomised trial assessing the clinical utility of a 2-week course of dexamethasone following a CSDH. Seven hundred fifty patients were randomised to either dexamethasone or placebo. The primary outcome is the modified Rankin Scale at 6 months which is dichotomised to favourable (a score of 0-3) versus unfavourable (a score of 4-6).

CONCLUSIONS

This paper and the accompanying additional material describe the statistical analysis plan for the trial.

TRIAL REGISTRATION

ISRCTN, ISRCTN80782810. Registered on 7 November 2014. http://www.isrctn.com/ISRCTN80782810. EudraCT, 2014-004948-35. Registered on 20 March 2015.

Knee Fix or Replace Trial (KFORT): a randomized controlled feasibility study

AIMS

The aim of this study was to assess the feasibility of conducting a full-scale, appropriately powered, randomized controlled trial (RCT) comparing internal fracture fixation and distal femoral replacement (DFR) for distal femoral fractures in older patients.

PATIENTS AND METHODS

Seven centres recruited patients into the study. Patients were eligible if they were greater than 65 years of age with a distal femoral fracture, and if the surgeon felt that they were suitable for either form of treatment. Outcome measures included the patients' willingness to participate, clinicians' willingness to recruit, rates of loss to follow-up, the ability to capture data, estimates of standard deviation to inform the sample size calculation, and the main determinants of cost. The primary clinical outcome measure was the EuroQol five-dimensional index (EQ-5D) at six months following injury.

RESULTS

Of 36 patients who met the inclusion criteria, five declined to participate and eight were not recruited, leaving 23 patients to be randomized. One patient withdrew before surgery. Of the remaining patients, five (23%) withdrew during the follow-up period and six (26%) died. A 100% response rate was achieved for the EQ-5D at each follow-up point, excluding one missing datapoint at baseline. In the DFR group, the mean cost of the implant outweighed the mean cost of many other items, including theatre time, length of stay, and readmissions. For a powered RCT, a total sample size of 1400 would be required with 234 centres recruiting over three years. At six months, the EQ-5D utility index was lower in the DFR group.

CONCLUSION

This study found that running a full-scale trial in this country would not be feasible. However, it may be feasible to undertake an international multicentre trial, and our findings provide some guidance about the power of such a study, the numbers required, and some challenges that should be anticipated and addressed. Cite this article: Bone Joint J 2019;101-B:1408-1415.

Parameter identification using moment of velocity

Many physical systems can be adequately modelled using a second-order approximation. Thus, the problem of system identification often reduces to the problem of estimating the position of a single pair of complex-conjugate poles. This paper presents a convenient but approximate technique for the estimation of the position of a single pair of complex-conjugate poles, using the moment of velocity (MoV). The MoV is a Hilbert transform based signal processing tool that addresses the shortcomings of instantaneous frequency. We demonstrate that the MoV can be employed for parameter identification of a dynamical system. We estimate the damping coefficient and oscillation frequency via MoV of the impulse response.

On moment of velocity for signal analysis

The instantaneous frequency (IF) of a signal is a well-defined quantity that is widely used for analysing non-stationary signals. However, often in practice, IF as a function of time can possess large spikes and negative values. Moreover, IF is very sensitive to noise, limiting its range of practical application. Due to these deficiencies, we introduce the concept of moment of velocity (MoV) for signal analysis. As a case study, we compare the performance of MoV to a standard Hilbert transform-based approach for R-wave identification in human electrocardiogram signals, demonstrating that our approach is more robust to noise. We examine characteristic heartbeats obtained from the MIT-BIH Arrhythmia database. A detection error rate of 0.07%, a positive predictive value of 99.97%, and a sensitivity of 99.95% are achieved against analysis results from the database.

TP1-3 Final phase of recruitment and statistics analysis plan for Dex-CSDH trial

Objectives

Review recruitment progression and statistical analysis plan for Dex-CSDH trial.

Design

A UK multi-centre, randomised, double-blind, placebo-controlled trial of dexamethasone versus placebo for CSDH.

Subjects

Symptomatic, adult CSDH patients admitted to a participating neurosurgical unit.

Methods

Trial participants receive a 2 week course of dexamethasone in addition to standard care, including surgery. The primary outcome measure is the modified Rankin Scale (mRS) at 6 months. An mRS of 0–3 requires the patient to be independently mobile and we have considered this a favourable outcome, with scores 4–6 (non-mobile) as unfavourable. The primary analysis will be performed on an intention-to-treat basis, estimating the absolute difference between the two treatment arms in the proportions achieving a favourable outcome. Secondary analysis will be done with an ordinal analysis of mRS scores and proportional odds logistic regression of the original mRS score adjusting for baseline covariates (age, GCS).

Results

629/750 patients (84%) have been recruited to the Dex-CSDH trial which is on-going as of 20-06-2018. Recruitment progress and follow-up at time of presentation will be reviewed alongside full statistical analysis plan.

Conclusions

The Dex-CSDH trial is drawing close to target following excellent recruitment across 22 UK centres. Transparent communication of the statistical analysis plan is essential prior to unblinding of the data. Up-to-date recruitment and primary endpoint completion rates will also be reviewed.

rpsftm: An R Package for Rank Preserving Structural Failure Time Models

Treatment switching in a randomised controlled trial occurs when participants change from their randomised treatment to the other trial treatment during the study. Failure to account for treatment switching in the analysis (i.e. by performing a standard intention-to-treat analysis) can lead to biased estimates of treatment efficacy. The rank preserving structural failure time model (RPSFTM) is a method used to adjust for treatment switching in trials with survival outcomes. The RPSFTM is due to Robins and Tsiatis (1991) and has been developed by White et al. (1997, 1999). The method is randomisation based and uses only the randomised treatment group, observed event times, and treatment history in order to estimate a causal treatment effect. The treatment effect, ψ, is estimated by balancing counter-factual event times (that would be observed if no treatment were received) between treatment groups. G-estimation is used to find the value of ψ such that a test statistic Z(ψ) = 0. This is usually the test statistic used in the intention-to-treat analysis, for example, the log rank test statistic. We present an R package that implements the method of rpsftm.

Evaluation of the use of midazolam as a co-induction agent with ketamine for anaesthesia in sedated ponies undergoing field castration

BACKGROUND

There are limited investigations comparing ketamine to a ketamine-midazolam co-induction.

OBJECTIVES

To compare quality and safety of general anaesthesia induced using ketamine alone with anaesthesia co-induced using ketamine and midazolam.

STUDY DESIGN

Randomised, double blinded, placebo controlled trial.

METHODS

After i.v. detomidine (20 μg/kg) thirty-eight ponies undergoing field castration received either 0.06 mg/kg (0.6 mL/50 kg) midazolam (group M) or 0.6 mL/50 kg placebo (group P) with 2.2 mg/kg ketamine i.v. for anaesthetic induction. Quality of anaesthetic induction, endotracheal intubation, surgical relaxation and recovery were scored using combinations of simple descriptive and visual analogue scales. Time of sedation, induction, start of endotracheal intubation, first movement, sternal recumbency and standing were recorded, as were time, number and total quantity of additional i.v. detomidine and ketamine injections. Cardiorespiratory variables were assessed every 5 min. Adverse effects were documented. Data were tested for normality and analysed with a mixed model ANOVA, Fisher's exact test, unpaired Students' t test and Wilcoxon Rank-sum as appropriate; P<0.05 was considered significant.

RESULTS

Group M had better scores for induction (P = 0.005), intubation (P<0.001) and surgical relaxation (P<0.001) and required fewer additional injections of detomidine and ketamine (P = 0.04). Time (minutes) from induction to first movement (P<0.001), sternal recumbency (P =< 0.001) and standing was longer (P = 0.05) in group M. Recoveries were uneventful with no difference in quality between groups (P = 0.78).

MAIN LIMITATIONS

Clinical study with noninvasive monitoring undertaken in field conditions.

CONCLUSIONS

Ketamine-midazolam co-induction compared to ketamine alone improved quality of induction, ease of intubation and muscle relaxation without impacting recovery quality.

Does hospital readmission following colorectal cancer resection and enhanced recovery after surgery affect long term survival?

AIM

Hospital readmission is undesirable for patients and care providers as this can affect short-term recovery and carries financial consequences. It is unknown if readmission has long-term implications. We aimed to investigate the impact of 30-day readmission on long-term overall survival (OS) following colorectal cancer resection within enhanced recovery after surgery (ERAS) care and explore the reasons for and the severity and details of readmission episodes.

METHOD

A dedicated, prospectively populated database was reviewed. All patients were managed within an established ERAS programme. Five-year OS was calculated using the Kaplan-Meier method. The number, reason for and severity of 30-day readmissions were classified according to the Clavien-Dindo (CD) system, along with total (initial and readmission) length of stay (LoS). Multivariate analysis was used to identify factors predicting readmission.

RESULTS

A total of 1023 consecutive patients underwent colorectal cancer resection between 2002 and 2015. Of these, 166 (16%) were readmitted. Readmission alone did not have a significant impact on 5-year OS (59% vs 70%, P = 0.092), but OS was worse in patients with longer total LoS (20 vs 14 days, P = 0.04). Of the readmissions, 121 (73%) were minor (CD I-II) and 27 (16%) required an intervention of which 16 (10%) were returned to theatre. Gut dysfunction 32 (19%) and wound complications 23 (14%) were the most frequent reasons for readmission. Prolonged initial LoS, rectal cancer and younger age predicted for hospital readmission.

CONCLUSION

Readmission does not have a significant impact on 5-year OS. A broad range of conditions led to readmission, with the majority representing minor complications.

Information needs and decision-making preferences of older women offered a choice between surgery and primary endocrine therapy for early breast cancer

OBJECTIVES

To establish older women's (≥75 years) information preferences regarding 2 breast cancer treatment options: surgery plus adjuvant endocrine therapy versus primary endocrine therapy. To quantify women's preferences for the mode of information presentation and decision-making (DM) style.

METHODS

This was a UK multicentre survey of women, ≥75 years, who had been offered a choice between PET and surgery at diagnosis of breast cancer. A questionnaire was developed including 2 validated scales of decision regret and DM preferences.

RESULTS

Questionnaires were sent to 247 women, and 101 were returned (response rate 41%). The median age of participants was 82 (range 75 to 99), with 58 having had surgery and 37 having PET. Practical details about the impact, safety, and efficacy of treatment were of most interest to participants. Of least interest were cosmetic outcomes after surgery. Information provided verbally by doctors and nurses, supported by booklets, was preferred. There was little interest in technology-based sources of information. There was equal preference for a patient- or doctor-centred DM style and lower preference for a shared DM style. The majority (74%) experienced their preferred DM style. Levels of decision regret were low (15.73, scale 0-100).

CONCLUSIONS

Women strongly preferred face to face information. Written formats were also helpful but not computer-based resources. Information that was found helpful to women in the DM process was identified. The study demonstrates many women achieved their preferred DM style, with a preference for involvement, and expressed low levels of decision regret.

Diagnostic accuracy of DXA compared to conventional spine radiographs for the detection of vertebral fractures in children

OBJECTIVES

In children, radiography is performed to diagnose vertebral fractures and dual energy x-ray absorptiometry (DXA) to assess bone density. In adults, DXA assesses both. We aimed to establish whether DXA can replace spine radiographs in assessment of paediatric vertebral fractures.

METHODS

Prospectively, lateral spine radiographs and lateral spine DXA of 250 children performed on the same day were independently scored by three radiologists using the simplified algorithm-based qualitative technique and blinded to results of the other modality. Consensus radiograph read and second read of 100 random images were performed. Diagnostic accuracy, inter/intraobserver and intermodality agreements, patient/carer experience and radiation dose were assessed.

RESULTS

Average sensitivity and specificity (95 % confidence interval) in diagnosing one or more vertebral fractures requiring treatment was 70 % (58-82 %) and 97 % (94-100 %) respectively for DXA and 74 % (55-93 %) and 96 % (95-98 %) for radiographs. Fleiss' kappa for interobserver and average kappa for intraobserver reliability were 0.371 and 0.631 respectively for DXA and 0.418 and 0.621 for radiographs. Average effective dose was 41.9 μSv for DXA and 232.7 μSv for radiographs. Image quality was similar.

CONCLUSION

Given comparable image quality and non-inferior diagnostic accuracy, lateral spine DXA should replace conventional radiographs for assessment of vertebral fractures in children.

KEY POINTS

• Vertebral fracture diagnostic accuracy of lateral spine DXA is non-inferior to radiographs. • The rate of unreadable vertebrae for DXA is lower than for radiographs. • Effective dose of DXA is significantly lower than radiographs. • Children prefer DXA to radiographs. • Given the above, DXA should replace radiographs for paediatric vertebral fracture assessment.

Adaptive designs undertaken in clinical research: a review of registered clinical trials

Adaptive designs have the potential to improve efficiency in the evaluation of new medical treatments in comparison to traditional fixed sample size designs. However, they are still not widely used in practice in clinical research. Little research has been conducted to investigate what adaptive designs are being undertaken. This review highlights the current state of registered adaptive designs and their characteristics. The review looked at phase II, II/III and III trials registered on ClinicalTrials.gov from 29 February 2000 to 1 June 2014, supplemented with trials from the National Institute for Health Research register and known adaptive trials. A range of adaptive design search terms were applied to the trials extracted from each database. Characteristics of the adaptive designs were then recorded including funder, therapeutic area and type of adaptation. The results in the paper suggest that the use of adaptive designs has increased. They seem to be most often used in phase II trials and in oncology. In phase III trials, the most popular form of adaptation is the group sequential design. The review failed to capture all trials with adaptive designs, which suggests that the reporting of adaptive designs, such as in clinical trials registers, needs much improving. We recommend that clinical trial registers should contain sections dedicated to the type and scope of the adaptation and that the term 'adaptive design' should be included in the trial title or at least in the brief summary or design sections.

Generalizing boundaries for triangular designs, and efficacy estimation at extended follow-ups

Background

Visceral leishmaniasis (VL) is a parasitic disease transmitted by sandflies and is fatal if left untreated. Phase II trials of new treatment regimens for VL are primarily carried out to evaluate safety and efficacy, while pharmacokinetic data are also important to inform future combination treatment regimens. The efficacy of VL treatments is evaluated at two time points, initial cure, when treatment is completed and definitive cure, commonly 6 months post end of treatment, to allow for slow response to treatment and detection of relapses.

This paper investigates a generalization of the triangular design to impose a minimum sample size for pharmacokinetic or other analyses, and methods to estimate efficacy at extended follow-up accounting for the sequential design and changes in cure status during extended follow-up.

Methods

We provided R functions that generalize the triangular design to impose a minimum sample size before allowing stopping for efficacy. For estimation of efficacy at a second, extended, follow-up time, the performance of a shrinkage estimator (SHE), a probability tree estimator (PTE) and the maximum likelihood estimator (MLE) for estimation was assessed by simulation.

Results

The SHE and PTE are viable approaches to estimate an extended follow-up although the SHE performed better than the PTE: the bias and root mean square error were lower and coverage probabilities higher.

Conclusions

Generalization of the triangular design is simple to implement for adaptations to meet requirements for pharmacokinetic analyses. Using the simple MLE approach to estimate efficacy at extended follow-up will lead to biased results, generally over-estimating treatment success. The SHE is recommended in trials of two or more treatments. The PTE is an acceptable alternative for one-arm trials or where use of the SHE is not possible due to computational complexity.

Trial registration

NCT01067443, February 2010.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-1018-1) contains supplementary material, which is available to authorized users.

The BioRap Biodiversity Assessment and Planning Study for Papua New Guinea

Papua New Guinea (PNG) has an incredible variety of land and marine ecosystems, including many components of biodiversity that are unique in the world. PNG's land mass constitutes less than one percent of the world's land area, yet estimates suggest that the country has more than 5% of the world's biodiversity. PNG has been recognized therefore as an important region for biodiversity conservation (see Alcorn 1993; Beehler 1993 and references within). Recently, Conservation International (CI) has recognized PNG as one of the small number of critical tropical forest areas for conservation efforts. That priority reflects not just PNG's unique biodiversity but also the fact that sustainable use of PNG's natural resources has become an important issue, particularly relating to its large mineral deposits, oil and natural gas reserves, agricultural potential, and forestry production potential. CI's perspective highlights important principles of conservation priority. PNG, like the other tropical wilderness areas on its priority list, is regarded as an opportunity for effective conservation at relatively low cost, given that these wilderness regions are still largely intact and have low human population density. In our view, realizing such opportunities requires good planning. Biodiversity conservation in PNG can imply low realized opportunity costs or quite high realized opportunity costs, depending on whether biodiversity planning is used to find a balance among society's competing needs through tradeoffs. PNG is a region worthy of urgent conservation planning attention because potential high net benefits for society may be needlessly foreclosed through inefficient planning that does not address conflicts among various needs of society. The risk of losing those potential net benefits is a strong argument for conservation investment in PNG.

Tensions in sharing client confidences while respecting autonomy: implications for interprofessional practice

This article aims to explore the ethical issues arising from the sharing of information in the context of interprofessional collaboration. The increased emphasis on interprofessional working has highlighted the need for greater collaboration and sharing of client information. Through the medium of a case study, we identify a number of tensions that arise from collaborative relationships, which are not conducive to supporting interprofessional working in an ethically sound manner. Within this article, it is argued that the way forward within these collaborative relationships is to set clear parameters to the professional-client relationship, paying full regard to the autonomy of both the clients and the professionals involved. We conclude that this approach to working will place the client at the centre of care provision and arguments used for not collaborating that are based on breaches of confidentiality will be negated. Using the approach offered, collaborative working will be not only possible but desirable.

Shared learning for primary health care teams: a success story

This paper sets out an educational model for shared learning for professionals working in primary health care teams (PHCTs). It presents an outline of an experiential educational programme using a simulated learning exercise based on a genogram. Multidisciplinary programmes are inherently problematic and tend to be ad hoc in their choice of educational theory. It was therefore our intention to discover the educational principles and theory that underpinned our innovative educational experience and to offer some fundamental criteria for the planning of future shared learning sessions in PHCTs. The process chosen to make the theory explicit was, 'reflecting on a critical incident' (Reed & Proctor 1993, Tripp 1993).

Effect of eight weeks of treatment with salmeterol on bronchoalveolar lavage inflammatory indices in asthmatics

Using BAL, we studied the effects of 8 wk of treatment with salmeterol on airway inflammation in nine asthmatic subjects in a double-blind crossover placebo-controlled protocol. The study patients were all receiving regular inhaled corticosteroid therapy (400 to 1,000 micrograms beclomethasone dipropionate per day) and inhaled albuterol for symptomatic relief, i.e., subjects who might be considered suitable for treatment with salmeterol. The asthmatic group had significant differences in numbers of epithelial cells and eosinophils in BAL compared with a group of 15 normal control subjects (p < 0.01). During salmeterol treatment mean morning and evening peak flow rates were increased (p < 0.05). There was no significant change in BAL cell profile and no change in percentages of CD4 and CD8 lymphocytes or proportion of lymphocytes expressing HLA-DR after salmeterol. In conclusion, we were unable to demonstrate any significant anti-inflammatory effect of regular salmeterol therapy on airway inflammation using BAL in these asthmatic patients. At the same time, there was equally no evidence of a deterioration in the underlying inflammatory disease process.

Dementia in acute units: the issues

To coincide with World Alzheimer's Day, Nursing Standard this week launches a major new series which looks in detail at one of the most pressing nursing problems of the age--coping with the behaviours of people with dementia who are admitted to acute care units. The series, which consists of seven articles, presented at monthly intervals, takes a very practical look at how nurses in such units can cope with patients who display behaviours such as wandering, aggression, sexual disinhibition and agitation--behaviours which nurses have difficulty understanding and managing.(ABSTRACT TRUNCATED AT 250 WORDS)

Pleuropulmonary abnormalities in primary Sjögren's syndrome

Sixteen patients with primary Sjögren's syndrome (1 degree SS) who complained of dyspnea were investigated with high resolution computerized tomography of the thorax, bronchoalveolar lavage, and transbronchial biopsy. Six patients had evidence of interstitial fibrosis, 5 had a peribronchiolar lymphocytic infiltration and 3 had pleural thickening. We conclude that significant pulmonary disease is not uncommon in patients with 1 degree SS.

Insulin-like growth factor expression in breast cancer epithelium and stroma

The insulin-like growth factors (IGFs) are mitogens for many cancer cell types. In breast cancer cells, IGF-I and IGF-II have both been shown to stimulate cell proliferation. However, IGF-I mRNA has not been found in human breast cancer cell lines, making it unlikely that IGF-I is commonly expressed as an autocrine growth factor for breast cancer cells. Nevertheless, IGF-I mRNA can be detected in breast cancer tissue samples, and in situ hybridization studies have shown that the message originates from the stromal cells adjacent to normal lobules. IGF-II, on the other hand, has been detected in some breast cancer cell lines. In the estrogen receptor positive cell line T47-D, IGF-II mRNA was induced by estradiol. Furthermore, transfection of an IGF-II expression vector into a previously estrogen-dependent cell line resulted in hormone independent growth. Thus, IGF-II can be expressed as an autocrine growth factor in some breast cancers and its expression may, in part, result in hormone independence. Finally, stromal cells obtained from breast tissues showed that IGF-I was commonly expressed in fibroblasts derived from non-malignant biopsy specimens, while IGF-II mRNA was detected in fibroblasts adjacent to malignant tissue. These studies suggest that IGF-II expression may be important in both autocrine and paracrine regulation of breast cancer cell growth.

Low-dose combination therapy of DUP-785 and RS-61443 prolongs cardiac allograft survival in rats

The introduction of cyclosporine into the immunosuppressive armamentarium has revolutionized transplant surgery with significant improvements in graft survival. The apparent lack of effect of cyclosporine on humoral rejection mechanisms makes the search for other immunosuppressive agents desirable. Two anti-metabolites affecting nucleotide synthesis via different pathways have recently been evaluated for their immunosuppressive potential. DUP-785 (DUP), also known as brequinar sodium, reversibly inhibits de novo pyrimidine synthesis by blocking dihydro-orotate dehydrogenase, thus resulting in the deletion of critical precursors for RNA and DNA synthesis. RS-61443, a morpholinoethyl ester of mycophenolic acid, reversibly and non-competitively blocks inosin monophosphate dehydrogenase, the key enzyme in purine de novo synthesis. A possible additive effect of both drugs was investigated in the rat heart allograft model.

Molecular cloning and primary structure of human glial fibrillary acidic protein

Glial fibrillary acidic protein (GFAP) is an intermediate-filament (IF) protein that is highly specific for cells of astroglial lineage, although its tissue-specific role is speculative. Determination of the primary structure of this protein should be of importance for understanding the functional role it plays in astroglia. Therefore, we isolated a cDNA clone encoding this protein and determined its nucleotide sequence. The predicted amino acid sequence indicates that GFAP shares structural similarities--particularly in the central rod domain and to a lesser degree in the carboxyl-terminal domain--with other IF proteins found in nonepithelial cell types. Considerable sequence divergence in the amino-terminal region of GFAP suggests that the tissue-specific functions of this IF protein might be mediated through this region of the molecule. In contrast, conservation of structural characteristics and a moderate degree of sequence conservation in the carboxyl-terminal region suggest functional similarities. Blot hybridization analysis using the GFAP cDNA as a probe failed to detect GFAP mRNA in both normal and neoplastic human tissues in which IF proteins other than GFAP are known to be expressed.

Molecular cloning and primary structure of human chromogranin A (secretory protein I) cDNA

Chromogranin A (CGA), also referred to as secretory protein I, is an acidic protein that has been detected in all neuroendocrine cell types examined and is often present in large amounts relative to other secreted proteins. For example, CGA comprises at least 40% of the soluble protein of the adrenal chromaffin granule, and it appears to be the major secretory protein in the parathyroid secretory granules. CGA complementary DNAs (cDNAs) from bovine adrenal and pituitary have recently been cloned and sequenced and found to be nearly identical. A region of bovine CGA has a high degree of amino acid sequence identity to pancreastatin, a recently isolated porcine peptide that inhibits glucose-induced insulin secretion. This suggests that CGA may be a prohormone. We have cloned and sequenced a human cDNA encoding CGA. This human CGA cDNA has an overall 86% nucleic acid identity to the bovine cDNA. Like the bovine CGA cDNA, the human cDNA has little homology to pancreastatin at the 5' region of this peptide but significant amino acid homology to the carboxyl-terminal portion of pancreastatin where the biologic activity resides. There is an area within the pancreastatin region of human CGA and porcine pancreastatin with a 70% amino acid identity to the calcium-binding moiety of the E-F hand proteins such as parvalbumin and oncomodulin. These data suggest that CGA and pancreastatin may both be members of a larger family of calcium-binding proteins.

Use of a low-power nerve stimulator during sciatic nerve block

The use of a low-power nerve stimulator to aid nerve location during the performance of sciatic nerve block was compared with a conventional anatomically based technique. The success rate, both in terms of the production of an effective block and the duration of postoperative analgesia, was significantly higher in the stimulator groups than in the non-stimulator groups. The implications of the study for both clinical and teaching practice are discussed.

Observations on the feeding and reproductive status of captive feather-tailed possums, Distoechurus pennatus (Marsupialia: Burramyidae)

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