A Systematic Review of Methodologies Used in Models of the Treatment of Diabetes Mellitus

BACKGROUND

Diabetes mellitus is a chronic and complex disease, increasing in prevalence and consequent health expenditure. Cost-effectiveness models with long time horizons are commonly used to perform economic evaluations of diabetes' treatments. As such, prediction accuracy and structural uncertainty are important features in cost-effectiveness models of chronic conditions.

OBJECTIVES

The aim of this systematic review is to identify and review published cost-effectiveness models of diabetes treatments developed between 2011 and 2022 regarding their methodological characteristics. Further, it also appraises the quality of the methods used, and discusses opportunities for further methodological research.

METHODS

A systematic literature review was conducted in MEDLINE and Embase to identify peer-reviewed papers reporting cost-effectiveness models of diabetes treatments, with time horizons of more than 5 years, published in English between 1 January 2011 and 31 of December 2022. Screening, full-text inclusion, data extraction, quality assessment and data synthesis using narrative synthesis were performed. The Philips checklist was used for quality assessment of the included studies. The study was registered in PROSPERO (CRD42021248999).

RESULTS

The literature search identified 30 studies presenting 29 unique cost-effectiveness models of type 1 and/or type 2 diabetes treatments. The review identified 26 type 2 diabetes mellitus (T2DM) models, 3 type 1 DM (T1DM) models and one model for both types of diabetes. Fifteen models were patient-level models, whereas 14 were at cohort level. Parameter uncertainty was assessed thoroughly in most of the models, whereas structural uncertainty was seldom addressed. All the models where validation was conducted performed well. The methodological quality of the models with respect to structure was high, whereas with respect to data modelling it was moderate.

CONCLUSIONS

Models developed in the past 12 years for health economic evaluations of diabetes treatments are of high-quality and make use of advanced methods. However, further developments are needed to improve the statistical modelling component of cost-effectiveness models and to provide better assessment of structural uncertainty.

Molnupiravir versus placebo in unvaccinated and vaccinated patients with early SARS-CoV-2 infection in the UK (AGILE CST-2): a randomised, placebo-controlled, double-blind, phase 2 trial

BACKGROUND

The antiviral drug molnupiravir was licensed for treating at-risk patients with COVID-19 on the basis of data from unvaccinated adults. We aimed to evaluate the safety and virological efficacy of molnupiravir in vaccinated and unvaccinated individuals with COVID-19.

METHODS

This randomised, placebo-controlled, double-blind, phase 2 trial (AGILE CST-2) was done at five National Institute for Health and Care Research sites in the UK. Eligible participants were adult (aged ≥18 years) outpatients with PCR-confirmed, mild-to-moderate SARS-CoV-2 infection who were within 5 days of symptom onset. Using permuted blocks (block size 2 or 4) and stratifying by site, participants were randomly assigned (1:1) to receive either molnupiravir (orally; 800 mg twice daily for 5 days) plus standard of care or matching placebo plus standard of care. The primary outcome was the time from randomisation to SARS-CoV-2 PCR negativity on nasopharyngeal swabs and was analysed by use of a Bayesian Cox proportional hazards model for estimating the probability of a superior virological response (hazard ratio [HR]>1) for molnupiravir versus placebo. Our primary model used a two-point prior based on equal prior probabilities (50%) that the HR was 1·0 or 1·5. We defined a priori that if the probability of a HR of more than 1 was more than 80% molnupiravir would be recommended for further testing. The primary outcome was analysed in the intention-to-treat population and safety was analysed in the safety population, comprising participants who had received at least one dose of allocated treatment. This trial is registered in ClinicalTrials.gov, NCT04746183, and the ISRCTN registry, ISRCTN27106947, and is ongoing.

FINDINGS

Between Nov 18, 2020, and March 16, 2022, 1723 patients were assessed for eligibility, of whom 180 were randomly assigned to receive either molnupiravir (n=90) or placebo (n=90) and were included in the intention-to-treat analysis. 103 (57%) of 180 participants were female and 77 (43%) were male and 90 (50%) participants had received at least one dose of a COVID-19 vaccine. SARS-CoV-2 infections with the delta (B.1.617.2; 72 [40%] of 180), alpha (B.1.1.7; 37 [21%]), omicron (B.1.1.529; 38 [21%]), and EU1 (B.1.177; 28 [16%]) variants were represented. All 180 participants received at least one dose of treatment and four participants discontinued the study (one in the molnupiravir group and three in the placebo group). Participants in the molnupiravir group had a faster median time from randomisation to negative PCR (8 days [95% CI 8-9]) than participants in the placebo group (11 days [10-11]; HR 1·30, 95% credible interval 0·92-1·71; log-rank p=0·074). The probability of molnupiravir being superior to placebo (HR>1) was 75·4%, which was less than our threshold of 80%. 73 (81%) of 90 participants in the molnupiravir group and 68 (76%) of 90 participants in the placebo group had at least one adverse event by day 29. One participant in the molnupiravir group and three participants in the placebo group had an adverse event of a Common Terminology Criteria for Adverse Events grade 3 or higher severity. No participants died (due to any cause) during the trial.

INTERPRETATION

We found molnupiravir to be well tolerated and, although our predefined threshold was not reached, we observed some evidence that molnupiravir has antiviral activity in vaccinated and unvaccinated individuals infected with a broad range of SARS-CoV-2 variants, although this evidence is not conclusive.

FUNDING

Ridgeback Biotherapeutics, the UK National Institute for Health and Care Research, the Medical Research Council, and the Wellcome Trust.

Baseline and peak cortisol response to the low dose short Synacthen test relates to indication for testing, age and sex

Objective

To review the outcomes of a simplified low dose Synacthen test (LDSST) performed in a tertiary endocrine service over seven years, and to examine for relationships between cortisol measurements and indication for testing, age and sex.

Design

Retrospective, observational study of LDSST performed in 2008 – 2014 (N=335) and 2016-2020 (N=160).

Methods

LDSST were performed by endocrine nurses. Synacthen 500ng/1.73m 2 administered as IV bolus, sampling at 0, 15, 25 and 35 minutes.

Results

Mean (± 1SD) baseline cortisol was 221 ± 120 nmol/L, peak 510 ± 166nmol/L and increment 210 ± 116 nmol/L. 336 (70%) of patients had a normal response (baseline cortisol >100nmol/L, peak >450nmol/L), 78 (16%) a suboptimal response (peak cortisol 350-450nmol/L) and were prescribed hydrocortisone to during periods of stress only, 67 (14%) an abnormal response (baseline <100nmol/L or peak <350nmol/L) and were prescribed daily hydrocortisone. Basal, peak and incremental increases in cortisol were higher in females (p=0.03, p<0.001, p=0.03 respectively). Abnormal results occurred most frequently in patients treated previously with pharmacological doses of glucocorticoids or structural brain abnormalities (p<0.0001).

Discussion

There are concerns that the specificity of the LDSST is poor. The low prevalence and strong association of abnormal results with indication for testing, suggests that over diagnosis occurred infrequently in this clinical setting.

Incidence and risk factors of long COVID in the UK: a single-centre observational study

BACKGROUND

Studies to evaluate long COVID symptoms and their risk factors are limited. We evaluated the presence of long COVID and its risk factors in patients discharged from a hospital with COVID-19 illness.

METHODS

This observational study included 271 COVID-19 patients admitted between February and July 2020 in a hospital in the UK. The primary outcome measure was to assess the duration and severity of long COVID and its predictors at 3, 6 and 9 months. Logistic regression was performed to assess the potential risk factors for long COVID.

RESULTS

Out of 89 patients interviewed, 55 (62%) had long COVID for 3 months, 46 (52%) for 6 months and 37 of the 75 patients admitted to the hospital with acute COVID-19 had long COVID for 9 months (49%). The most common long COVID symptoms were fatigue and breathlessness.

CONCLUSION

Nearly two-thirds of patients at 3 months and a half at 9 months had long COVID. COVID-19 pneumonia was the strongest predictor of long COVID in Caucasians at 3 months.

Salivary cortisol, cortisone and serum cortisol concentrations are related to age and body mass index in healthy children and young people

BACKGROUND

Saliva is an ideal medium in which to measure cortisol in children. However, there are very few data reporting salivary cortisol or cortisone concentrations in healthy children since the introduction of liquid chromatography-mass spectrometry (LC-MS/MS) to routine laboratory practice.

DESIGN

Early morning serum cortisol, salivary cortisol and cortisone were measured on fasting samples, and salivary hormones were measured in samples collected every 2 hours during waking hours, and 30 minutes after waking the following morning.

PARTICIPANTS

43 healthy paediatric volunteers (19 female), median age 11.5 years, range 6.2-18.7, participated.

RESULTS

Early morning serum cortisol (265 nmol/L, 156-516) correlated strongly with salivary cortisol (4.7 nmol/L, 1.1-14.6) and cortisone (28.8 nmol/L, 11.7-56.6), P < .0001 for both. Serum cortisol, salivary cortisol and salivary cortisone correlated directly with age (P < .0001, P = .002 and P = .015, respectively), and salivary cortisone/cortisol ratio correlated indirectly with age (P = .007). Between 08.00 and 21.00, area under the curve for salivary cortisol (mean ± 1 SD) was 41.8 ± 19.1 and for cortisone 213.0 ± 61.2. Salivary cortisol was undetectable in 25/130 (19%) of samples collected after 13.00, while cortisone was always detectable.

DISCUSSION

Salivary cortisol and cortisone concentrations are strongly related to serum cortisol concentrations; however, cortisone may be a preferable measure as cortisol is often undetectable. Age may be an important factor in the interpretation of early morning cortisol measurements made in serum and saliva.

The role of the home environment in neurocognitive development of children living in extreme poverty and with frequent illnesses: a cross-sectional study

Background: The home environment is reported to contribute significantly to children’s developing cognitive skills. However, it is not yet evident whether this role prevails in the context of extreme poverty and frequent ill-health. We therefore investigated the role of the home environment in Ugandan children taking into account the frequent infections and extreme poverty in which they lived.

Methods: Cognitive abilities of 163 5-year-old children were assessed. Home environments of these children, their health status and family socioeconomic status (SES) were assessed respectively using the EC-HOME, anthropometry and illnesses, and traditional SES measures. Structural equation analyses compared five models on the influence of the home environment, SES, and child health on the cognitive scores.

Results: The model in which the home environment mediates the combined influence of SES and child health on cognitive performance showed a particularly good fit to the data compared with the four alternative models, i.e. those in which the HOME, SES and health independently influence cognitive performance.

Conclusions: Home environments providing cognitive stimulation can enable children to overcome effects of major adverse life experiences on cognitive development.

Creation of the WHO Indicators of Infant and Young Child Development (IYCD): metadata synthesis across 10 countries

BACKGROUND

Renewed global commitment to the improvement of early child development outcomes, as evidenced by the focus of the United Nations Sustainable Development Goal 4, highlights an increased need for reliable and valid measures to evaluate preventive and interventional efforts designed to affect change. Our objective was to create a new tool, applicable across multicultures, to measure development from 0 to 3 years through metadata synthesis.

METHODS

Fourteen cross-sectional data sets were contributed on 21 083 children from 10 low/middle-income countries (LMIC), assessed using seven different tools (caregiver reported or directly assessed). Item groups, measuring similar developmental skills, were identified by item mapping across tools. Logistic regression curves displayed developmental trajectories for item groups across countries and age. Following expert consensus to identify well-performing items across developmental domains, a second mapping exercise was conducted to fill any gaps across the age range. The first version of the tool was constructed. Item response analysis validated our approach by putting all data sets onto a common scale.

RESULTS

789 individual items were identified across tools in the first mapping and 129 item groups selected for analysis. 70 item groups were then selected through consensus, based on statistical performance and perceived importance, with a further 50 items identified at second mapping. A tool comprising 120 items (23 fine motor, 23 gross motor, 20 receptive language, 24 expressive language, 30 socioemotional) was created. The linked data sets on a common scale showed a curvilinear trajectory of child development, highlighting the validity of our approach through excellent coverage by age and consistency of measurement across contributed tools, a novel finding in itself.

CONCLUSIONS

We have created the first version of a prototype tool for measuring children in the early years, developed using novel easy to apply methodology; now it needs to be feasibility tested and piloted across several LMICs.

Performance of different clinical trial designs to evaluate treatments during an epidemic

In the 2013-2016 west Africa outbreak of Ebola Virus Disease (EVD), most of the planned clinical trials failed to reach a conclusion within the time frame of the epidemic. The performance of clinical trial designs for the evaluation of one or more experimental treatments in the specific context of an ongoing epidemic with changing case fatality rates (CFR) and unpredictable case numbers is unclear. We conduct a comprehensive evaluation of commonly used two- and multi-arm clinical trial designs based on real data, which was recorded during the 2013-16 EVD epidemic in west Africa. The primary endpoint is death within 14 days of hospitalization. The impact of the recruitment start times relative to the time course of the epidemic on the operating characteristics of the clinical trials is analysed. Designs with frequent interim analyses with the possibility of early stopping are shown to outperform designs with only a single analysis not only in terms of average time to conclusion and average sample size, but also in terms of the probability of reaching any conclusion at all. Historic control designs almost always result in substantially inflated false positive rates, when the case fatality rate changes over time. Response-adaptive randomization may be a compromise between the goal of scientific validity and the ethical goal of minimizing the number of patients allocated to ineffective treatments.

A proposal for a new PhD level curriculum on quantitative methods for drug development

This paper provides an overview of "Improving Design, Evaluation and Analysis of early drug development Studies" (IDEAS), a European Commission-funded network bringing together leading academic institutions and small- to large-sized pharmaceutical companies to train a cohort of graduate-level medical statisticians. The network is composed of a diverse mix of public and private sector partners spread across Europe, which will host 14 early-stage researchers for 36 months. IDEAS training activities are composed of a well-rounded mixture of specialist methodological components and generic transferable skills. Particular attention is paid to fostering collaborations between researchers and supervisors, which span academia and the private sector. Within this paper, we review existing medical statistics programmes (MSc and PhD) and highlight the training they provide on skills relevant to drug development. Motivated by this review and our experiences with the IDEAS project, we propose a concept for a joint, harmonised European PhD programme to train statisticians in quantitative methods for drug development.

Instrumental variable estimation in semi-parametric additive hazards models

Instrumental variable methods allow unbiased estimation in the presence of unmeasured confounders when an appropriate instrumental variable is available. Two‐stage least‐squares and residual inclusion methods have recently been adapted to additive hazard models for censored survival data. The semi‐parametric additive hazard model which can include time‐independent and time‐dependent covariate effects is particularly suited for the two‐stage residual inclusion method, since it allows direct estimation of time‐independent covariate effects without restricting the effect of the residual on the hazard. In this article, we prove asymptotic normality of two‐stage residual inclusion estimators of regression coefficients in a semi‐parametric additive hazard model with time‐independent and time‐dependent covariate effects. We consider the cases of continuous and binary exposure. Estimation of the conditional survival function given observed covariates is discussed and a resampling scheme is proposed to obtain simultaneous confidence bands. The new methods are compared to existing ones in a simulation study and are applied to a real data set. The proposed methods perform favorably especially in cases with exposure‐dependent censoring.

PET-PANC: multicentre prospective diagnostic accuracy and health economic analysis study of the impact of combined modality 18fluorine-2-fluoro-2-deoxy-d-glucose positron emission tomography with computed tomography scanning in the diagnosis and management of pancreatic cancer

BACKGROUND

Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission tomography (PET)/computed tomography (CT) adds precise anatomical localisation to functional data. The use of PET/CT may add further value to the diagnosis and staging of pancreatic cancer.

OBJECTIVE

To determine the incremental diagnostic accuracy and impact of PET/CT in addition to standard diagnostic work-up in patients with suspected pancreatic cancer.

DESIGN

A multicentre prospective diagnostic accuracy and clinical value study of PET/CT in suspected pancreatic malignancy.

PARTICIPANTS

Patients with suspected pancreatic malignancy.

INTERVENTIONS

All patients to undergo PET/CT following standard diagnostic work-up.

MAIN OUTCOME MEASURES

The primary outcome was the incremental diagnostic value of PET/CT in addition to standard diagnostic work-up with multidetector computed tomography (MDCT). Secondary outcomes were (1) changes in patients' diagnosis, staging and management as a result of PET/CT; (2) changes in the costs and effectiveness of patient management as a result of PET/CT; (3) the incremental diagnostic value of PET/CT in chronic pancreatitis; (4) the identification of groups of patients who would benefit most from PET/CT; and (5) the incremental diagnostic value of PET/CT in other pancreatic tumours.

RESULTS

Between 2011 and 2013, 589 patients with suspected pancreatic cancer underwent MDCT and PET/CT, with 550 patients having complete data and in-range PET/CT. Sensitivity and specificity for the diagnosis of pancreatic cancer were 88.5% and 70.6%, respectively, for MDCT and 92.7% and 75.8%, respectively, for PET/CT. The maximum standardised uptake value (SUVmax.) for a pancreatic cancer diagnosis was 7.5. PET/CT demonstrated a significant improvement in relative sensitivity (p = 0.01) and specificity (p = 0.023) compared with MDCT. Incremental likelihood ratios demonstrated that PET/CT significantly improved diagnostic accuracy in all scenarios (p < 0.0002). PET/CT correctly changed the staging of pancreatic cancer in 56 patients (p = 0.001). PET/CT influenced management in 250 (45%) patients. PET/CT stopped resection in 58 (20%) patients who were due to have surgery. The benefit of PET/CT was limited in patients with chronic pancreatitis or other pancreatic tumours. PET/CT was associated with a gain in quality-adjusted life-years of 0.0157 (95% confidence interval -0.0101 to 0.0430). In the base-case model PET/CT was seen to dominate MDCT alone and is thus highly likely to be cost-effective for the UK NHS. PET/CT was seen to be most cost-effective for the subgroup of patients with suspected pancreatic cancer who were thought to be resectable.

CONCLUSION

PET/CT provided a significant incremental diagnostic benefit in the diagnosis of pancreatic cancer and significantly influenced the staging and management of patients. PET/CT had limited utility in chronic pancreatitis and other pancreatic tumours. PET/CT is likely to be cost-effective at current reimbursement rates for PET/CT to the UK NHS. This was not a randomised controlled trial and therefore we do not have any information from patients who would have undergone MDCT only for comparison. In addition, there were issues in estimating costs for PET/CT. Future work should evaluate the role of PET/CT in intraductal papillary mucinous neoplasm and prognosis and response to therapy in patients with pancreatic cancer.

STUDY REGISTRATION

Current Controlled Trials ISRCTN73852054 and UKCRN 8166.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Estimation in multi-arm two-stage trials with treatment selection and time-to-event endpoint

We consider estimation of treatment effects in two‐stage adaptive multi‐arm trials with a common control. The best treatment is selected at interim, and the primary endpoint is modeled via a Cox proportional hazards model. The maximum partial‐likelihood estimator of the log hazard ratio of the selected treatment will overestimate the true treatment effect in this case. Several methods for reducing the selection bias have been proposed for normal endpoints, including an iterative method based on the estimated conditional selection biases and a shrinkage approach based on empirical Bayes theory. We adapt these methods to time‐to‐event data and compare the bias and mean squared error of all methods in an extensive simulation study and apply the proposed methods to reconstructed data from the FOCUS trial. We find that all methods tend to overcorrect the bias, and only the shrinkage methods can reduce the mean squared error. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

A retrospective study of seven-day consultant working: reductions in mortality and length of stay

Weekend admission is associated with higher in-hospital mortality than weekday admission. Whether providing enhanced weekend staffing for acute medical inpatient services reduces mortality or length of stay is unknown.

METHODS

This paper describes a retrospective analysis of in-hospital mortality and length of stay before and after introduction of an enhanced, consultant-led weekend service in acute medicine in November 2012. In-hospital mortality was compared for matching admission calendar months before and after introduction of the new service, adjusted for case volume. Length of stay and 30-day postdischarge mortality were also compared; illness severity of patients admitted was assessed by cross-sectional acuity audits.

RESULTS

Admission numbers increased from 6,304 (November 2011-July 2012) to 7,382 (November 2012-July 2013), with no change in acuity score in elderly medical patients but a small fall in younger patients. At the same time, however, a 57% increase in early-warning score triggered calls was seen in 2013 (410 calls vs 262 calls in 2012; p<0.01). Seven-day consultant working was associated with a reduction in in-hospital mortality from 11.4% to 8.8% (p<0.001). Mortality within 30 days of discharge fell from 2.4% to 2.0% (p=0.12). Length of stay fell by 1.9 days (95% CI 1.1-2.7; p=0.004) for elderly medicine wards and by 1.7 days (95% CI 0.8-2.6; p=0.008) for medical wards. Weekend discharges increased from general medical wards (from 13.6% to 18.8%, p<0.001) but did not increase from elderly medicine wards.

CONCLUSIONS

Introduction of an enhanced, consultant-led model of working at weekends was associated with reduced in-hospital and 30-day post discharge mortality rates as well as reduced length of stay. These results require confirmation in rigorously designed prospective studies.

Long-term follow-up reveals low incidence of colorectal cancer, but frequent need for resection, among Australian patients with inflammatory bowel disease

BACKGROUND & AIMS

Inflammatory bowel disease can require surgical resection and also lead to colorectal cancer (CRC). We investigated the cumulative incidence of resection surgeries and CRC among patients with ulcerative colitis (UC) or Crohn's disease (CD).

METHODS

We analyzed data from a cohort of patients who participated in an inflammatory bowel disease study (504 with UC and 377 with CD) at 2 academic medical centers in Sydney, Australia from 1977 to 1992 (before the development of biologic therapies). We collected follow-up data on surgeries and development of CRC from hospital and community medical records or via direct contact with patients during a median time period of 14 years. Cumulative incidences of resection surgeries and CRC were calculated by competing risk survival analysis.

RESULTS

Among patients with UC, CRC developed in 24, for a cumulative incidence of 1% at 10 years (95% confidence interval [CI], 0%-2%), 3% at 20 years (95% CI, 1%-5%), and 7% at 30 years (95% CI, 4%-10%). Their cumulative incidence of colectomy was 15% at 10 years (95% CI, 11%-19%), 26% at 20 years (95% CI, 21%-30%), and 31% at 30 years (95% CI, 25%-36%). Among patients with CD, 5 of 327 with colon disease developed CRC, with a cumulative incidence of CRC of 1% at 10 years (95% CI, 0%-2%), 1% at 20 years (95% CI, 0%-2%), and 2% at 30 years (95% CI, 0%-4%). Among all patients with CD, the cumulative incidence of resection was 32% at 5 years (95% CI, 27%-37%), 43% at 10 years (95% CI, 37%-49%), and 53% at 15 years (95% CI, 46%-58%). Of these 168 subjects, 42% required a second resection within 15 years of the first surgery (95% CI, 33%-50%).

CONCLUSIONS

Patients with UC have a low incidence of CRC during a 30-year period (7% or less); the incidence among patients with CD is even lower. However, almost one-third of patients with UC and about 50% of those with CD will require surgery.

Early morning salivary cortisol and cortisone, and adrenal responses to a simplified low-dose short Synacthen test in children with asthma

OBJECTIVE

To examine serum cortisol responses to a simplified low-dose short Synacthen test (LDSST) in children treated with inhaled corticosteroids (ICS) for asthma and to compare these to early morning salivary cortisol (EMSC) and cortisone (EMSCn) levels.

DESIGN

Early morning salivary cortisol and EMSCn samples were collected for three consecutive days. On day three, Synacthen 500 ng/1·73 m(2) was administered intravenously. Samples were collected at 0, 15, 25, 35 min.

RESULTS

A total of 269 subjects (160 M: 109 F), median (range) age 10·0 (5·1-15·2) years were studied. Peak cortisol in the LDSST was <500 nmol/l in 101 subjects (37·5%) and <350 nmol/l in 12 subjects (4·5%). Basal cortisol correlated with peak cortisol: r = 0·55, (95% CI: 0·46, 0·63, P < 0·0001). Time at which peak cortisol concentration was achieved was significantly related to the value of peak cortisol (P < 0·0001), with higher cortisol peaks occurring later in the test and lower cortisol peaks occurring earlier. EMSC and EMSCn had no predictive value for the identification of patients with a peak cortisol <500 nmol/l. EMSCn was superior to EMSC in identifying patients with a peak cortisol <350 nmol/l: a minimum EMSCn cut-off value of 12·5 nmol/l gave a negative predictive value of 99·2% and positive predictive value of 30·1%.

CONCLUSION

Our data illustrate that basal measures of cortisol are likely to be of value in screening populations for patients at greatest risk of adrenal crisis. EMSCn shows promise as a screening tool for the identification of patients with severe adrenal insufficiency.

Measurement of flood peak effects as a result of soil and land management, with focus on experimental issues and scale

As a result of several serious flood events which have occurred since 2000, flooding across Europe is now receiving considerable public and media attention. The impact of land use on hydrology and flood response is significantly under-researched, and the links between land use change and flooding are still unclear. This study considers runoff data available from studies of arable in-field land use management options, applied with the aim of reducing diffuse pollution from arable land, in order to investigate whether these treatments also have potential to reduce downstream flooding. Intensive monitoring of 17 hillslope treatment areas produced a record of flood peak data covering different mitigation treatments for runoff which occurred in the winter of 2007-2008. We investigated event total runoff responses to rainfall, peak runoff, and timing of the runoff peaks from replicates of different treatments, in order to assess whether there is a significant difference in flood peak response between different mitigation options which could be used to mitigate downstream flood risk. A mixed-modelling approach was adopted in order to determine whether differences observed in runoff response were significant. The results of this study suggest that changes in land use management using arable in-field mitigation treatments can affect local-scale runoff generation, with differences observed in the size, duration and timing of flood peaks as a result of different management practices, but the study was unable to allow significant treatment effects to be determined. We suggest that further field studies of the effects of changes in land use and land use management need to upscale towards farm and catchment scale experiments which consider high quality before-and-after data over longer temporal timescales. This type of data collection is essential in order to allow appropriate land use management decisions to be made.

Two-year outcomes for infants with low cord pH at birth

OBJECTIVE

To determine the long-term outcome of infants born with cord pH ≤ 7.0 and no clinical evidence of asphyxia at birth.

DESIGN

SETTING

Tertiary Referral Centre. A prospective matched cohort study was conducted. 51 term infants were recruited following singleton birth with venous cord pH ≤ 7.0. For each recruited baby a healthy baby with normal cord pH ≥ 7.20 was recruited matched for gestation, gender and mode of delivery. Ages and Stages Questionnaires (ASQ)(TM) and Health Screening Questionnaires (HSQ) were sent out at 24 months of age. Two independent assessors, blinded to the case assignment, reviewed intrapartum and neonatal events to look for clinical evidence of birth asphyxia among the cases.

RESULT

From 102 infants recruited, 62 questionnaires (24 cases, 38 controls) were returned. 20 matched pairs with no clinical evidence of birth asphyxia were available for analysis. The groups were similar except in terms of birth weight; the pH ≥ 7.0 group had mean birth weight 584 g lower than controls (p = 0.005). The ASQ motor scores were lower in children born with low cord pH (p = 0.019); however, once adjusted for birth weight, the difference was not significant (p = 0.289).

CONCLUSION

It is unlikely that abnormal cord pH in otherwise healthy neonates leads to a substantially increased risk of abnormal neurodevelopmental outcome or severe health problems by 2 years of age.

Development and psychometric testing of the online Adolescent Diabetes Needs Assessment Tool (ADNAT)

AIM

To report on the development and psychometric testing of the Adolescent Diabetes Needs Assessment Tool.

BACKGROUND

The UK has the fifth largest paediatric diabetes population in the world, but one of the poorest levels of diabetes control, highlighting the need for intervention development.

DESIGN

Mixed methods following recommendations for questionnaire design and validation.

METHODS

A total of 171 young people (12-18 years) participated between 2008- 2011. Methods included item selection using secondary framework analysis, item review, pre-testing, piloting and online transfer. Statistical tests assessed reliability using item-total correlations, interitem consistency and test-retest reliability; and validity using blood glucose (HbA1c) levels and the Self-Management of type 1 Diabetes in Adolescence questionnaire.

RESULTS

The Adolescent Diabetes Needs Assessment Tool consists of 117 questions divided between six domains of educational and psychosocial support needs. It combines reflective questioning with needs assessment to raise self-awareness to support adolescent decision-making in relation to diabetes self-care. Thirty-six of the questions provide self-care and psychosocial health assessment scores. Face and content validity of the scoring items were all positively evaluated in terms of appropriateness and readability and tests for validity found significant correlations with Self-Management of type 1 Diabetes in Adolescence and weak correlation with HbA1c , which compared favourably with Self-Management of type 1 Diabetes in Adolescence, the only comparable (USA) tool. Item response analysis validated the use of simple additive scores.

CONCLUSIONS

The Adolescent Diabetes Needs Assessment Tool combines reflective learning with needs assessment to support patient-centred clinical consultations.

Disease-specific survival benefit of lung transplantation in adults: a national cohort study

The lung transplantation candidate population is heterogeneous and survival benefit has not been established for all patient groups. UK data from a cohort of 1997 adult (aged > or = 16), first lung transplant candidates (listed July 1995 to July 2006, follow-up to December 2007) were analyzed by diagnosis, to assess mortality relative to continued listing. Donor lungs were primarily allocated according to local criteria. Diagnosis groups studied were cystic fibrosis (430), bronchiectasis (123), pulmonary hypertension (74), diffuse parenchymal lung disease (564), chronic obstructive pulmonary disease (COPD, 647) and other (159). The proportion of patients in each group who died while listed varied significantly (respectively 37%, 48%, 41%, 49%, 19%, 38%). All groups had an increased risk of death at transplant, which fell below waiting list risk of death within 4.3 months. Thereafter, the hazard ratio for death relative to listing ranged from 0.34 for cystic fibrosis to 0.64 for COPD (p < 0.05 all groups except pulmonary hypertension). Mortality reduction was greater after bilateral lung transplantation in pulmonary fibrosis patients (p = 0.049), but not in COPD patients. Transplantation appeared to improve survival for all groups. Differential waiting list and posttransplant mortality by diagnosis suggest further use and development of algorithms to inform lung allocation.