Whole-brain diffusion tensor imaging predicts 6-month functional outcome in acute intracerebral haemorrhage

INTRODUCTION

Small vessel disease (SVD) causes most spontaneous intracerebral haemorrhage (ICH) and is associated with widespread microstructural brain tissue disruption, which can be quantified via diffusion tensor imaging (DTI) metrics: mean diffusivity (MD) and fractional anisotropy (FA). Little is known about the impact of whole-brain microstructural alterations after SVD-related ICH. We aimed to investigate: (1) association between whole-brain DTI metrics and functional outcome after ICH; and (2) predictive ability of these metrics compared to the pre-existing ICH score.

METHODS

Sixty-eight patients (38.2% lobar) were retrospectively included. We assessed whole-brain DTI metrics (obtained within 5 days after ICH) in cortical and deep grey matter and white matter. We used univariable logistic regression to assess the associations between DTI and clinical-radiological variables and poor outcome (modified Rankin Scale > 2). We determined the optimal predictive variables (via LASSO estimation) in: model 1 (DTI variables only), model 2 (DTI plus non-DTI variables), model 3 (DTI plus ICH score). Optimism-adjusted C-statistics were calculated for each model and compared (likelihood ratio test) against the ICH score.

RESULTS

Deep grey matter MD (OR 1.04 [95% CI 1.01-1.07], p = 0.010) and white matter MD (OR 1.11 [95% CI 1.01-1.23], p = 0.044) were associated (univariate analysis) with poor outcome. Discrimination values for model 1 (0.67 [95% CI 0.52-0.83]), model 2 (0.71 [95% CI 0.57-0.85) and model 3 (0.66 [95% CI 0.52-0.82]) were all significantly higher than the ICH score (0.62 [95% CI 0.49-0.75]).

CONCLUSION

Our exploratory study suggests that whole-brain microstructural disruption measured by DTI is associated with poor 6-month functional outcome after SVD-related ICH. Whole-brain DTI metrics performed better at predicting recovery than the existing ICH score.

Predicting prognosis for adults with depression using individual symptom data: a comparison of modelling approaches

BACKGROUND

This study aimed to develop, validate and compare the performance of models predicting post-treatment outcomes for depressed adults based on pre-treatment data.

METHODS

Individual patient data from all six eligible randomised controlled trials were used to develop (k = 3, n = 1722) and test (k = 3, n = 918) nine models. Predictors included depressive and anxiety symptoms, social support, life events and alcohol use. Weighted sum scores were developed using coefficient weights derived from network centrality statistics (models 1-3) and factor loadings from a confirmatory factor analysis (model 4). Unweighted sum score models were tested using elastic net regularised (ENR) and ordinary least squares (OLS) regression (models 5 and 6). Individual items were then included in ENR and OLS (models 7 and 8). All models were compared to one another and to a null model (mean post-baseline Beck Depression Inventory Second Edition (BDI-II) score in the training data: model 9). Primary outcome: BDI-II scores at 3-4 months.

RESULTS

Models 1-7 all outperformed the null model and model 8. Model performance was very similar across models 1-6, meaning that differential weights applied to the baseline sum scores had little impact.

CONCLUSIONS

Any of the modelling techniques (models 1-7) could be used to inform prognostic predictions for depressed adults with differences in the proportions of patients reaching remission based on the predicted severity of depressive symptoms post-treatment. However, the majority of variance in prognosis remained unexplained. It may be necessary to include a broader range of biopsychosocial variables to better adjudicate between competing models, and to derive models with greater clinical utility for treatment-seeking adults with depression.

Short-term risk prediction after major lower limb amputation: PERCEIVE study

BACKGROUND

The accuracy with which healthcare professionals (HCPs) and risk prediction tools predict outcomes after major lower limb amputation (MLLA) is uncertain. The aim of this study was to evaluate the accuracy of predicting short-term (30 days after MLLA) mortality, morbidity, and revisional surgery.

METHODS

The PERCEIVE (PrEdiction of Risk and Communication of outcomE following major lower limb amputation: a collaboratIVE) study was launched on 1 October 2020. It was an international multicentre study, including adults undergoing MLLA for complications of peripheral arterial disease and/or diabetes. Preoperative predictions of 30-day mortality, morbidity, and MLLA revision by surgeons and anaesthetists were recorded. Probabilities from relevant risk prediction tools were calculated. Evaluation of accuracy included measures of discrimination, calibration, and overall performance.

RESULTS

Some 537 patients were included. HCPs had acceptable discrimination in predicting mortality (931 predictions; C-statistic 0.758) and MLLA revision (565 predictions; C-statistic 0.756), but were poor at predicting morbidity (980 predictions; C-statistic 0.616). They overpredicted the risk of all outcomes. All except three risk prediction tools had worse discrimination than HCPs for predicting mortality (C-statistics 0.789, 0.774, and 0.773); two of these significantly overestimated the risk compared with HCPs. SORT version 2 (the only tool incorporating HCP predictions) demonstrated better calibration and overall performance (Brier score 0.082) than HCPs. Tools predicting morbidity and MLLA revision had poor discrimination (C-statistics 0.520 and 0.679).

CONCLUSION

Clinicians predicted mortality and MLLA revision well, but predicted morbidity poorly. They overestimated the risk of mortality, morbidity, and MLLA revision. Most short-term risk prediction tools had poorer discrimination or calibration than HCPs. The best method of predicting mortality was a statistical tool that incorporated HCP estimation.

Sex inequities in the performance of the GRACE 2.0 score in non-ST-segment elevation acute coronary syndromes: a multinational observational study in contemporary cohorts from four European countries

Background

The Global Registry of Acute Coronary Events (GRACE) score was developed and validated in predominantly male patient populations. Growing evidence indicates distinct pathophysiologic and clinical characteristics of non-ST-segment elevation acute coronary syndromes (NSTE-ACS) in women and men.

Purpose

We aimed to assess sex differences in the performance of the GRACE score in NSTE-ACS in contemporary populations.

Methods

We calculated GRACE 2.0 risk estimates for patients with NSTE-ACS in contemporary nation-wide ACS cohorts from England, Wales, and Northern Ireland (MINAP, 2005–2017, n=400,054) and from Switzerland (AMIS Plus, 2005–2020, n=20,727; SPUM-ACS, 2009–2017, n=2,239). Sex disaggregated analyses were stratified according to the mortality endpoint of the score (in-hospital death, death at 6 months, death at 1 year), the clinical setting (calculated at admission and calculated for hospital survivors, respectively), the geographic region (United Kingdom and Switzerland, respectively) and the level of care (all hospitals and PCI-capable university hospitals, respectively). The area under the receiver operating characteristic curve (AUC), the average prediction error (APE), and the misclassification rate (MCR) were compared between women and men.

Results

The discriminatory performance of GRACE 2.0 for in-hospital death was lower and the APE and MCR were higher in women as compared to men in the United Kingdom (AUC female: 80.4%, 95% confidence interval [CI], 80.0 to 80.8, AUC male: 84.7%, 95% CI, 84.4 to 85.1, p<0.001; APE female: 0.0512, 95% CI, 0.0501–0.0522, APE male: 0.0357, 95% CI, 0.0351 to 0.0363; MCR female: 5.81%, 95% CI, 5.68 to 5.94, MCR male: 3.96, 95% CI, 3.89 to 4.03) and in Switzerland (AUC female: 84.2%, 95% CI, 81.4 to 86.8, AUC male: 88.5%, 95% CI 87.1–89.7, p=0.003; APE female: 0.0420, 95% CI 0.0376 to 0.0465, APE male: 0.0312, 95% CI 0.0289 to 0.0335; MCR female: 4.98%, 95% CI 4.39 to 5.56, MCR male: 3.69%, 95% CI, 3.39 to 4.00). Similar results were obtained for 6-month death and 1-year death endpoints across clinical settings, geographic regions, and levels of care. The risk of in-hospital death relative to males was increased in females that GRACE 2.0 classified as low-to-intermediate risk (suggesting no early invasive management strategy) in the United Kingdom (relative risk [RR]: 1.61, 95% CI, 1.50 to 1.74, p<0.001) and in Switzerland (RR: 1.84, 95% CI, 1.28 to 2.64, p<0.001).

Conclusion

Thus far, this is the largest investigation on the GRACE risk score. We confirmed good overall score performance and found decreased performance in contemporary female patients with NSTE-ACS irrespective of the mortality endpoint, the clinical setting, the geographic region, and the level of care.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science FoundationSwiss Heart Foundation

Acute corticospinal tract diffusion tensor imaging predicts 6-month functional outcome after intracerebral haemorrhage

INTRODUCTION

Diffusion tensor imaging (DTI) can assess the structural integrity of the corticospinal tract (CST) in vivo. We aimed to investigate whether CST DTI metrics after intracerebral haemorrhage (ICH) are associated with 6-month functional outcome and can improve the predictive performance of the existing ICH score.

METHODS

We retrospectively included 42 patients with DTI performed within 5 days after deep supratentorial spontaneous ICH. Ipsilesional-to-contralesional ratios were calculated for fractional anisotropy (rFA) and mean diffusivity (rMD) in the pontine segment (PS) of the CST. We determined the most predictive variables for poor 6-month functional outcome [modified Rankin Scale (mRS) > 2] using the least absolute shrinkage and selection operator (LASSO) method. We calculated discrimination using optimism-adjusted estimation of the area under the curve (AUC).

RESULTS

Patients with 6-month mRS > 2 had lower rFA (0.945 [± 0.139] vs 1.045 [± 0.130]; OR 0.004 [95% CI 0.00-0.77]; p =  0.04) and higher rMD (1.233 [± 0.418] vs 0.963 [± 0.211]; OR 22.5 [95% CI 1.46-519.68]; p = 0.02). Discrimination (AUC) values were: 0.76 (95% CI 0.61-0.91) for the ICH score, 0.71 (95% CI 0.54-0.89) for rFA, and 0.72 (95% CI 0.61-0.91) for rMD. Combined models with DTI and non-DTI variables offer an improvement in discrimination: for the best model, the AUC was 0.82 ([95% CI 0.68-0.95]; p = 0.15).

CONCLUSION

In our exploratory study, PS-CST rFA and rMD had comparable predictive ability to the ICH score for 6-month functional outcome. Adding DTI metrics to clinical-radiological scores might improve discrimination, but this needs to be investigated in larger studies.

A Phase 2a randomized, single-center, double-blind, placebo-controlled study to evaluate the safety and preliminary efficacy of oral iOWH032 against cholera diarrhea in a controlled human infection model

Cholera remains a major cause of infectious diarrhea globally. Despite the increased availability of cholera vaccines, there is still an urgent need for other effective interventions to reduce morbidity and mortality. Furthermore, increased prevalence of antibiotic-resistant Vibrio cholerae threatens the use of many drugs commonly used to treat cholera. We developed iOWH032, a synthetic small molecule inhibitor of the cystic fibrosis transmembrane conductance regulator chloride channel, as an antisecretory, host-directed therapeutic for cholera. In the study reported here, we tested iOWH032 in a Phase 2a cholera controlled human infection model. Forty-seven subjects were experimentally infected with V. cholerae El Tor Inaba strain N16961 in an inpatient setting and randomized to receive 500 mg iOWH032 or placebo by mouth every 8 hours for 3 days to determine the safety and efficacy of the compound as a potential treatment for cholera. We found that iOWH032 was generally safe and achieved a mean (± standard deviation) plasma level of 4,270 ng/mL (±2,170) after 3 days of oral dosing. However, the median (95% confidence interval) diarrheal stool output rate for the iOWH032 group was 25.4 mL/hour (8.9, 58.3), compared to 32.6 mL/hour (15.8, 48.2) for the placebo group, a reduction of 23%, which was not statistically significant. There was also no significant decrease in diarrhea severity and number or frequency of stools associated with iOWH032 treatment. We conclude that iOWH032 does not merit future development for treatment of cholera and offer lessons learned for others developing antisecretory therapeutic candidates that seek to demonstrate proof of principle in a cholera controlled human infection model study.

Trial registration: This study is registered with ClinicalTrials.gov as NCT04150250.

Cholera, a disease caused by infection with the bacterium Vibrio cholerae, remains a major cause of diarrheal illness and death, particularly in settings with poor sanitation and hygiene. We developed a synthetic chemical, named “iOWH032,” as a potential treatment for cholera, which is administered as oral tablets. The chemical acts by blocking secretions from cells in the intestine, and thereby was expected to prevent fluid loss and dehydration caused by cholera illness. We tested iOWH032 in a clinical study using a cholera human challenge model. Study volunteers were intentionally infected with V. cholerae in an inpatient clinic setting to better study the effects of iOWH032 on infected individuals. This challenge model had been used previously to test cholera vaccine candidates, but this study represents the first test of a potential cholera treatment using the model. We found that treatment of individuals with iOWH032 was safe, but did not result in a significant reduction of cholera illness, based on several different measurements of diarrheal symptoms and severity. This study demonstrates how human challenge models incorporating a relatively small number of subjects can help support decision-making about potential new therapeutics and other interventions for infectious diseases.

Reference and point-of-care testing for G6PD deficiency: Blood disorder interference, contrived specimens, and fingerstick equivalence and precision

Certain clinical indications and treatments such as the use of rasburicase in cancer therapy and 8-aminoquinolines for Plasmodium vivax malaria treatment would benefit from a point-of-care test for glucose-6-phosphate dehydrogenase (G6PD) deficiency. Three studies were conducted to evaluate the performance of one such test: the STANDARD^™ G6PD Test (SD BIOSENSOR, South Korea). First, biological interference on the test performance was evaluated in specimens with common blood disorders, including high white blood cell (WBC) counts. Second, the test precision on fingerstick specimens was evaluated against five individuals of each, deficient, intermediate, and normal G6PD activity status. Third, clinical performance of the test was evaluated at three point-of-care settings in the United States. The test performed equivalently to the reference assay in specimens with common blood disorders. High WBC count blood samples resulted in overestimation of G6PD activity in both the reference assay and the STANDARD G6PD Test. The STANDARD G6PD Test showed good precision on multiple fingerstick specimens from the same individual. The same G6PD threshold values (U/g Hb) were applied for a semiquantitative interpretation for fingerstick- and venous-derived results. The sensitivity/specificity values (95% confidence intervals) for the test for G6PD deficiency were 100 (92.3–100.0)/97 (95.2–98.2) and 100 (95.7–100.0)/97.4 (95.7–98.5) for venous and capillary specimens, respectively. The same values for females with intermediate (> 30% to ≤ 70%) G6PD activity were 94.1 (71.3–99.9)/88.2 (83.9–91.7) and 82.4 (56.6–96.2)/87.6(83.3–91.2) for venous and capillary specimens, respectively. The STANDARD G6PD Test enables point-of-care testing for G6PD deficiency.

Role of age, gender and marital status in prognosis for adults with depression: An individual patient data meta-analysis

AIMS

To determine whether age, gender and marital status are associated with prognosis for adults with depression who sought treatment in primary care.

METHODS

Medline, Embase, PsycINFO and Cochrane Central were searched from inception to 1st December 2020 for randomised controlled trials (RCTs) of adults seeking treatment for depression from their general practitioners, that used the Revised Clinical Interview Schedule so that there was uniformity in the measurement of clinical prognostic factors, and that reported on age, gender and marital status. Individual participant data were gathered from all nine eligible RCTs (N = 4864). Two-stage random-effects meta-analyses were conducted to ascertain the independent association between: (i) age, (ii) gender and (iii) marital status, and depressive symptoms at 3-4, 6-8, and 9-12 months post-baseline and remission at 3-4 months. Risk of bias was evaluated using QUIPS and quality was assessed using GRADE. PROSPERO registration: CRD42019129512. Pre-registered protocol https://osf.io/e5zup/.

RESULTS

There was no evidence of an association between age and prognosis before or after adjusting for depressive 'disorder characteristics' that are associated with prognosis (symptom severity, durations of depression and anxiety, comorbid panic disorderand a history of antidepressant treatment). Difference in mean depressive symptom score at 3-4 months post-baseline per-5-year increase in age = 0(95% CI: -0.02 to 0.02). There was no evidence for a difference in prognoses for men and women at 3-4 months or 9-12 months post-baseline, but men had worse prognoses at 6-8 months (percentage difference in depressive symptoms for men compared to women: 15.08% (95% CI: 4.82 to 26.35)). However, this was largely driven by a single study that contributed data at 6-8 months and not the other time points. Further, there was little evidence for an association after adjusting for depressive 'disorder characteristics' and employment status (12.23% (-1.69 to 28.12)). Participants that were either single (percentage difference in depressive symptoms for single participants: 9.25% (95% CI: 2.78 to 16.13) or no longer married (8.02% (95% CI: 1.31 to 15.18)) had worse prognoses than those that were married, even after adjusting for depressive 'disorder characteristics' and all available confounders.

CONCLUSION

Clinicians and researchers will continue to routinely record age and gender, but despite their importance for incidence and prevalence of depression, they appear to offer little information regarding prognosis. Patients that are single or no longer married may be expected to have slightly worse prognoses than those that are married. Ensuring this is recorded routinely alongside depressive 'disorder characteristics' in clinic may be important.

The importance of transdiagnostic symptom level assessment to understanding prognosis for depressed adults: analysis of data from six randomised control trials

BACKGROUND

Depression is commonly perceived as a single underlying disease with a number of potential treatment options. However, patients with major depression differ dramatically in their symptom presentation and comorbidities, e.g. with anxiety disorders. There are also large variations in treatment outcomes and associations of some anxiety comorbidities with poorer prognoses, but limited understanding as to why, and little information to inform the clinical management of depression. There is a need to improve our understanding of depression, incorporating anxiety comorbidity, and consider the association of a wide range of symptoms with treatment outcomes.

METHOD

Individual patient data from six RCTs of depressed patients (total n = 2858) were used to estimate the differential impact symptoms have on outcomes at three post intervention time points using individual items and sum scores. Symptom networks (graphical Gaussian model) were estimated to explore the functional relations among symptoms of depression and anxiety and compare networks for treatment remitters and those with persistent symptoms to identify potential prognostic indicators.

RESULTS

Item-level prediction performed similarly to sum scores when predicting outcomes at 3 to 4 months and 6 to 8 months, but outperformed sum scores for 9 to 12 months. Pessimism emerged as the most important predictive symptom (relative to all other symptoms), across these time points. In the network structure at study entry, symptoms clustered into physical symptoms, cognitive symptoms, and anxiety symptoms. Sadness, pessimism, and indecision acted as bridges between communities, with sadness and failure/worthlessness being the most central (i.e. interconnected) symptoms. Connectivity of networks at study entry did not differ for future remitters vs. those with persistent symptoms.

CONCLUSION

The relative importance of specific symptoms in association with outcomes and the interactions within the network highlight the value of transdiagnostic assessment and formulation of symptoms to both treatment and prognosis. We discuss the potential for complementary statistical approaches to improve our understanding of psychopathology.

Growth patterns and their contributing factors among HIV-exposed uninfected infants

With expanded HIV treatment and prevention programmes, most infants born to HIV‐positive women are uninfected, but the patterns and determinants of their growth are not well described. This study aimed to assess growth patterns in a cohort of HIV‐exposed uninfected (HEU) infants who participated in an experimental HIV vaccine trial and to test for associations with maternal and infant factors, including in‐utero exposure to antiretroviral therapy (ART), mode of delivery, exclusive breastfeeding, mother's education and receipt of the vaccine. Infants in the trial were seen at regular clinic visits from birth to 48 weeks of age. From the anthropometric measurements at these visits, weight‐for‐age z‐scores (WAZ), weight‐for‐length z‐scores (WLZ) and length‐for‐age z‐scores (LAZ) were computed using World Health Organization (WHO) software and reference tables. Growth patterns were investigated with respect to maternal and infant factors, using linear mixed regression models. From 94 infants included at birth, growth data were available for 75.5% at 48 weeks. The determinants of infant growth in this population are multifactorial: infant LAZ during the first year was significantly lower among infants delivered by caesarean section (p = 0.043); both WAZ and LAZ were depressed among infants with longer exposure to maternal ART (WAZ: p = 0.015; LAZ: p < 0.0001) and among infants of mothers with lower educational level (WAZ: p = 0.038; LAZ: p < 0.0001); the effect of maternal education was modified by breastfeeding practice, with no differences seen in exclusively breastfed infants. These findings inform intervention strategies to preserve growth in this vulnerable infant population.

Baseline factors associated with early and late death in intracerebral haemorrhage survivors

Background and purpose

The aim of this study was to determine whether early and late death are associated with different baseline factors in intracerebral haemorrhage (ICH) survivors.

Methods

This was a secondary analysis of the multicentre prospective observational CROMIS‐2 ICH study. Death was defined as ‘early’ if occurring within 6 months of study entry and ‘late’ if occurring after this time point.

Results

In our cohort (n = 1094), there were 306 deaths (per 100 patient‐years: absolute event rate, 11.7; 95% confidence intervals, 10.5–13.1); 156 were ‘early’ and 150 ‘late’. In multivariable analyses, early death was independently associated with age [per year increase; hazard ratio (HR), 1.05, P = 0.003], history of hypertension (HR, 1.89, P = 0.038), pre‐event modified Rankin scale score (per point increase; HR, 1.41, P < 0.0001), admission National Institutes of Health Stroke Scale score (per point increase; HR, 1.11, P < 0.0001) and haemorrhage volume >60 mL (HR, 4.08, P < 0.0001). Late death showed independent associations with age (per year increase; HR, 1.04, P = 0.003), pre‐event modified Rankin scale score (per point increase; HR, 1.42, P = 0.001), prior anticoagulant use (HR, 2.13, P = 0.028) and the presence of intraventricular extension (HR, 1.73, P = 0.033) in multivariable analyses. In further analyses where time was treated as continuous (rather than dichotomized), the HR of previous cerebral ischaemic events increased with time, whereas HRs for Glasgow Coma Scale score, National Institutes of Health Stroke Scale score and ICH volume decreased over time.

Conclusions

We provide new evidence that not all baseline factors associated with early mortality after ICH are associated with mortality after 6 months and that the effects of baseline variables change over time. Our findings could help design better prognostic scores for later death after ICH.

Title Correction: Clinical Outcomes of Pneumonia and Other Comorbidities in Children Aged 2-59 Months in Lilongwe, Malawi: Protocol for the Prospective Observational Study “Innovative Treatments in Pneumonia”

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Clinical Outcomes of Pneumonia and Other Comorbidities in Children Aged 2-59 Months in Lilongwe, Malawi: Protocol for the Prospective Observational Study "Innovative Treatments in Pneumonia"

Background

Pneumonia is the leading infectious cause of death worldwide among children below 5 years of age. Clinical trials are conducted to determine optimal treatment; however, these trials often exclude children with comorbidities and severe illness.

Conclusions

Given the paucity of data from Africa, African-based research is necessary to establish optimal management of childhood pneumonia in malaria-endemic settings in the region. An expanded evidence base that includes children with pneumonia and other comorbidities, who are at high risk for mortality or have other complications and are therefore typically excluded from childhood pneumonia clinical trials, can contribute to future iterations of the World Health Organization Integrated Management of Childhood Illness guidelines.

Methods

The study enrolled 1000 children with pneumonia presenting to the outpatient departments of Kamuzu Central or Bwaila District Hospitals in Lilongwe, Malawi, who were excluded from concurrent randomized controlled clinical trials investigating fast breathing and chest indrawing pneumonia and who met the inclusion criteria for this prospective observational study. Each child received standard care for their illnesses per Malawian guidelines and hospital protocol and was prospectively followed up with scheduled study visits on days 1, 2 (if hospitalized), 6, 14 (in person), and 30 (by phone). Our primary objectives are to describe the clinical outcomes of children who meet the inclusion criteria for this study and to investigate whether the percentages of children cured at day 14 among those with either fast breathing or chest indrawing pneumonia and comorbidities such as severe malaria, anemia, severe acute malnutrition, or HIV are lower than those in children without these comorbidities in the standard care groups in concurrent clinical trials. This study was approved by the Western Institutional Review Board, Malawi College of Medicine Research and Ethics Committee, and the Malawi Pharmacy, Medicines and Poisons Board.

Objective

This prospective observational study aimed to assess the clinical outcomes of children aged 2-59 months with both pneumonia and other comorbidities in a malaria-endemic region of Malawi.

Results

The Innovative Treatments in Pneumonia project was funded by the Bill and Melinda Gates Foundation (OPP1105080) in April 2014. Enrollment in this study began in 2016, and the primary results are expected in 2019.

International Registered Report Identifier (IRRID)

DERR1-10.2196/13377

Should fast breathing pneumonia cases be treated with antibiotics? The scientific rationale for revisiting management in Low and Middle income countries

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World Health Organization (WHO) recommends oral antibiotic treatment for all children with fast breathing pneumonia.

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However evidence for the guidance is weak and infections are often viral and self-limiting.

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Further information regarding the true rationale for conducting non-inferiority trials to test the hypothesis that antibiotics may not be necessary for children with fast breathing as the sole symptomatology.

Background

Pneumonia is the largest single contributor to child mortality and the problem is more acute in low and middle income countries. The World Health Organization (WHO) currently recommends oral antibiotic treatment for all children with fast breathing pneumonia without danger signs. It is, however, widely acknowledged that most such infections are viral and self-limiting and that the evidence for the guidance is weak.

Rationale

Overuse of antibiotics exposes children to adverse events, increases cost for families, burdens already stretched health care resources and may contribute to development of antibiotic resistance.

Conclusion

There is equipoise regarding utility of antibiotic in case of fast breathing pneumonia and no high quality trial evidence exists. This paper provides further information behind the rationale for conducting non-inferiority trials to test the hypothesis that antibiotics may not be necessary for children with fast breathing as the sole symptomatology.

Prospective evaluation of IOTA logistic regression models LR1 and LR2 in comparison with subjective pattern recognition for diagnosis of ovarian cancer in an outpatient setting

OBJECTIVE

To determine whether International Ovarian Tumor Analysis (IOTA) logistic regression models LR1 and LR2 developed for the preoperative diagnosis of ovarian cancer could also be used to differentiate between benign and malignant adnexal tumors in the population of women attending gynecology outpatient clinics.

METHODS

This was a single-center prospective observational study of consecutive women attending our gynecological diagnostic outpatient unit, recruited between May 2009 and January 2012. All the women were first examined by a Level-II ultrasound operator. In those diagnosed with adnexal tumors, the IOTA-LR1/2 protocol was used to evaluate the masses. The LR1 and LR2 models were then used to assess the risk of malignancy. Subsequently, the women were also examined by a Level-III examiner, who used pattern recognition to differentiate between benign and malignant tumors. Women with an ultrasound diagnosis of malignancy were offered surgery, while asymptomatic women with presumed benign lesions were offered conservative management with a minimum follow-up of 12 months. The initial diagnosis was compared with two reference standards: histological findings and/or a comparative assessment of tumor morphology on follow-up ultrasound scans. All women for whom the tumor classification on follow-up changed from benign to malignant were offered surgery.

RESULTS

In the final analysis, 489 women who had either or both of the reference standards were included. Their mean age was 50 years (range, 16-91 years) and 45% were postmenopausal. Of the included women, 342/489 (69.9%) had surgery and 147/489 (30.1%) were managed conservatively. The malignancy rate was 137/489 (28.0%). Overall, sensitivities of LR1 and LR2 for the diagnosis of malignancy were 97.1% (95% CI, 92.7-99.2%) and 94.9% (95% CI, 89.8-97.9%) and specificities were 77.3% (95% CI, 72.5-81.5%) and 76.7% (95% CI, 71.9-81.0%), respectively (P > 0.05). In comparison with pattern recognition (sensitivity 94.2% (95% CI, 88.8-97.4%), specificity 96.3% (95% CI, 93.8-98.0%)), the specificities of the IOTA models were significantly lower (P < 0.0001). A significantly higher number of women would have been offered surgery for suspected cancer if the women had been assessed using the IOTA models instead of pattern recognition (213/489 (43.6%) vs 142/489 (29.0%); P < 0.001).

CONCLUSIONS

The IOTA models maintained their high sensitivity when used in an outpatient setting. Specificity was relatively low, which indicates that a significant proportion of the women would have been offered unnecessary surgery for suspected ovarian cancer. These findings show that the IOTA models could be used as a first-stage test to diagnose ovarian cancer in an outpatient setting, but a different second-stage test is required to minimize the number of false-positive findings. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Convexity subarachnoid haemorrhage has a high risk of intracerebral haemorrhage in suspected cerebral amyloid angiopathy

The risk of future symptomatic intracerebral haemorrhage (sICH) remains uncertain in patients with acute convexity subarachnoid haemorrhage (cSAH) associated with suspected cerebral amyloid angiopathy (CAA). We assessed the risk of future sICH in patients presenting to our comprehensive stroke service with acute non-traumatic cSAH due to suspected CAA, between 2011 and 2016. We conducted a systematic search and pooled analysis including our cohort and other published studies including similar cohorts. Our hospital cohort included 20 patients (mean age 69 years; 60% male); 12 (60%) had probable CAA, and 6 (30%) had possible CAA according to the modified Boston criteria; two did not meet CAA criteria because of age <55 years, but were judged likely to be due to CAA. Fourteen patients (70%) had cortical superficial siderosis; 12 (60%) had cerebral microbleeds. Over a mean follow-up period of 19 months, 2 patients (9%) suffered sICH, both with probable CAA (annual sICH risk for probable CAA 8%). In a pooled analysis including our cohort and eight other studies (n = 172), the overall sICH rate per patient-year was 16% (95% CI 11–24%). In those with probable CAA (n = 104), the sICH rate per patient-year was 19% (95% CI 13–27%), compared to 7% (95% CI 3–15%) for those without probable CAA (n = 72). Patients with acute cSAH associated with suspected CAA are at high risk of future sICH (16% per patient-year); probable CAA might carry the highest risk.

Single-dose systemic methotrexate vs expectant management for treatment of tubal ectopic pregnancy: a placebo-controlled randomized trial

OBJECTIVE

Methotrexate is used routinely worldwide for the medical treatment of clinically stable women with a tubal ectopic pregnancy. This is despite the lack of robust evidence to show its superior effectiveness over expectant management. The aim of our multicenter randomized controlled trial was to compare success rates of methotrexate against placebo for the conservative treatment of tubal ectopic pregnancy.

METHODS

This study took place in two early-pregnancy units in the UK between August 2005 and June 2014. Inclusion criteria were clinically stable women with a conclusive ultrasound diagnosis of a tubal ectopic pregnancy, presenting with a low serum beta human chorionic gonadotropin (β-hCG) level of < 1500 IU/L. Women were assigned randomly to a single systemic injection of either 50 mg/m² methotrexate or placebo. The primary outcome was a binary indicator for success of conservative management, defined as resolution of clinical symptoms and decline of serum β-hCG to < 20 IU/L or a negative urine pregnancy test without the need for any additional medical intervention. An intention-to-treat analysis was followed.

RESULTS

We recruited a total of 80 women, 42 of whom were assigned to methotrexate and 38 to placebo. The arms of the study were matched in terms of age, ethnicity, obstetric history, pregnancy characteristics and serum levels of β-hCG and progesterone. The rates of success were similar for the two study arms: 83% with methotrexate and 76% with placebo. On univariate analysis, this difference was not statistically significant (χ² (1 degree of freedom) = 0.53; P = 0.47). On multivariate logistic regression, the serum level of β-hCG was the only covariate found to be significantly associated with outcome. The odds of failure increased by 0.15% for each unit increase in β-hCG (odds ratio, 1.0015 (95% CI, 1.0002-1.003); P = 0.02). In 14 women presenting with serum β-hCG of 1000-1500 IU/L, the success rate was 33% in those managed expectantly compared with 62% in those receiving methotrexate. This difference was not statistically significant and a larger sample size would be needed to give sufficient power to detect a difference in the subgroup of women with higher β-hCG. In women with successful conservative treatment, there was no significant difference in median β-hCG resolution times between study arms (17.5 (interquartile range (IQR), 14-28.0) days (n = 30) in the methotrexate group vs 14 (IQR, 7-29.5) days (n = 25) in the placebo group; P = 0.73).

CONCLUSIONS

The results of our study do not support the routine use of methotrexate for the treatment of clinically stable women diagnosed with tubal ectopic pregnancy presenting with low serum β-hCG (< 1500 IU/L). Further work is required to identify a subgroup of women with tubal ectopic pregnancy and β-hCG ≥ 1500 IU/L in whom methotrexate may offer a safe and cost-effective alternative to surgery. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Comparación entre una sola dosis de metotrexate sistémico y la conducta expectante en el tratamiento de casos de embarazo ectópico tubárico: un ensayo aleatorio controlado con placebo RESUMEN OBJETIVO: El metotrexate se utiliza de modo rutinario en todo el mundo para el tratamiento de las mujeres clínicamente estables con un embarazo ectópico tubárico. Esto sucede a pesar de la falta de evidencia rigurosa que demuestre que su eficacia es superior a la conducta expectante. El objetivo de este ensayo controlado aleatorio multicéntrico fue comparar las tasas de éxito del metotrexate con las de un placebo para el tratamiento cauteloso del embarazo ectópico tubárico. MÉTODOS: Este estudio se llevó a cabo en dos clínicas de control de gestación temprana en el Reino Unido entre agosto de 2005 y junio de 2014. Los criterios de inclusión fueron mujeres clínicamente estables con un diagnóstico ecográfico concluyente de embarazo ectópico tubárico, las cuáles presentaban una concentración sérica baja de la β hormona coriónica gonadotrópica (β-hCG) inferior a 1500 UI/L. Las mujeres fueron asignadas aleatoriamente a una sola inyección sistémica de 50 mg/m2 de metotrexate o a placebo. El resultado primario fue un indicador binario del éxito del tratamiento conservador, definido como la resolución de los síntomas clínicos y la disminución en el suero de la β-hCG a <20 UI/L o una prueba de embarazo negativa en orina sin la necesidad de ninguna intervención médica adicional. Se hizo un análisis por intención de tratar.

RESULTADOS

Se reclutó un total de 80 mujeres; a 42 de ellas se les asignó el metotrexate y a 38 el placebo. Los grupos del estudio se realizaron en función de la edad, el origen étnico, los antecedentes obstétricos, las características del embarazo y los niveles séricos de la β-hCG y la progesterona. Las tasas de éxito fueron similares para los dos grupos de estudio: 83% con metotrexate y 76% con placebo. En el análisis univariante, esta diferencia no fue estadísticamente significativa (χ2 (1 grado de libertad) = 0,53; P = 0,47). En la regresión logística multivariante, el nivel sérico de la β-hCG fue la única covariable que se encontró significativamente asociada con el resultado. Las probabilidades de fracaso aumentaron en un 0,15% por cada unidad de aumento de la β-hCG (cociente de probabilidad 1,0015 (IC 95%, 1,0002-1,003); P = 0,02). La tasa de éxito en las 14 mujeres con un nivel sérico de la β-hCG de 1000-1500 UI/L fue del 33% en las tratadas con conducta expectante frente al 62% en las que recibieron metotrexate. Esta diferencia no fue estadísticamente significativa, por lo que se necesitaría un tamaño de muestra mayor, lo suficiente como para poder detectar diferencias en el subgrupo de mujeres con una β-hCG más elevada. En las mujeres en las que el tratamiento conservador tuvo éxito, no hubo una diferencia significativa en la mediana de los tiempos de resolución de la ß-hCG entre los grupos del estudio (17,5 (amplitud intercuartílica (IQR), 14-28,0) días (n = 30) en el grupo de metotrexate frente a 14 (IQR, 7-29.5) días (n = 25) en el grupo de placebo; P = 0,73).

CONCLUSIONES

Los resultados de este estudio no apoyan el uso rutinario de metotrexate para el tratamiento de las mujeres clínicamente estables diagnosticadas con un embarazo ectópico tubárico que presenta un nivel sérico bajo la β-hCG (<1500 UI/L). Serán necesarios estudios adicionales para identificar un subgrupo de mujeres con embarazo ectópico tubárico y β-hCG ≥1500 UI/L para quienes el metotrexate puede ofrecer una alternativa segura y rentable en comparación con la cirugía. : : ,,。。 : 2005820146,2。,,β(beta human chorionic gonadotropin,β-hCG)<1500 IU/L。,(50 mg/m² )。,β-hCG<20 IU/L,。。 : 80,42,38。2、、、β-hCG。2:83%,76%。,[χ² (1)=0.53;P=0.47]。logistic,β-hCG。β-hCG,0.15%[,1.0015(95% CI,1.0002~1.003);P=0.02]。14β-hCG1000~1500 IU/L,33%,62%。,β-hCG。,2β-hCG(P=0.73),17.5[(interquartile range,IQR),14~28.0](n=30),14 (IQR,7~29.5)(n=25)。 : 、、β-hCG(<1500 IU/L)。,β-hCG>1500 IU/L、。.

mPneumonia, an Innovation for Diagnosing and Treating Childhood Pneumonia in Low-Resource Settings: A Feasibility, Usability and Acceptability Study in Ghana

Pneumonia is the leading cause of infectious disease mortality in children. Currently, health care providers (HCPs) are trained to use World Health Organization Integrated Management of Childhood Illness (IMCI) paper-based protocols and manually assess respiratory rate to diagnose pneumonia in low-resource settings (LRS). However, this approach of relying on clinical signs alone has proven problematic. Hypoxemia, a diagnostic indicator of pneumonia severity associated with an increased risk of death, is not assessed because pulse oximetry is often not available in LRS. To improve HCPs’ ability to diagnose, classify, and manage pneumonia and other childhood illnesses, “mPneumonia” was developed. mPneumonia is a mobile health application that integrates a digital version of the IMCI algorithm with a software-based breath counter and a pulse oximeter. A design-stage qualitative pilot study was conducted to assess feasibility, usability, and acceptability of mPneumonia in six health centers and five community-based health planning and services centers in Ghana. Nine health administrators, 30 HCPs, and 30 caregivers were interviewed. Transcribed interview audio recordings were coded and analyzed for common themes. Health administrators reported mPneumonia would be feasible to implement with approval and buy-in from national and regional decision makers. HCPs felt using the mPneumonia application would be feasible to integrate into their work with the potential to improve accurate patient care. They reported it was “easy to use” and provided confidence in diagnosis and treatment recommendations. HCPs and caregivers viewed the pulse oximeter and breath counter favorably. Challenges included electricity requirements for charging and the time needed to complete the application. Some caregivers saw mPneumonia as a sign of modernity, increasing their trust in the care received. Other caregivers were hesitant or confused about the new technology. Overall, this technology was valued by users and is a promising innovation for improving quality of care in frontline health facilities.

Stepped-wedge cluster randomised controlled trial to assess the effectiveness of an electronic medication management system to reduce medication errors, adverse drug events and average length of stay at two paediatric hospitals: a study protocol

INTRODUCTION

Medication errors are the most frequent cause of preventable harm in hospitals. Medication management in paediatric patients is particularly complex and consequently potential for harms are greater than in adults. Electronic medication management (eMM) systems are heralded as a highly effective intervention to reduce adverse drug events (ADEs), yet internationally evidence of their effectiveness in paediatric populations is limited. This study will assess the effectiveness of an eMM system to reduce medication errors, ADEs and length of stay (LOS). The study will also investigate system impact on clinical work processes.

METHODS AND ANALYSIS

A stepped-wedge cluster randomised controlled trial (SWCRCT) will measure changes pre-eMM and post-eMM system implementation in prescribing and medication administration error (MAE) rates, potential and actual ADEs, and average LOS. In stage 1, 8 wards within the first paediatric hospital will be randomised to receive the eMM system 1 week apart. In stage 2, the second paediatric hospital will randomise implementation of a modified eMM and outcomes will be assessed. Prescribing errors will be identified through record reviews, and MAEs through direct observation of nurses and record reviews. Actual and potential severity will be assigned. Outcomes will be assessed at the patient-level using mixed models, taking into account correlation of admissions within wards and multiple admissions for the same patient, with adjustment for potential confounders. Interviews and direct observation of clinicians will investigate the effects of the system on workflow. Data from site 1 will be used to develop improvements in the eMM and implemented at site 2, where the SWCRCT design will be repeated (stage 2).

ETHICS AND DISSEMINATION

The research has been approved by the Human Research Ethics Committee of the Sydney Children's Hospitals Network and Macquarie University. Results will be reported through academic journals and seminar and conference presentations.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ANZCTR) 370325.

The effect of neoadjuvant chemotherapy and chemoradiotherapy on exercise capacity and outcome following upper gastrointestinal cancer surgery: an observational cohort study

Background

In 2014 approximately 21,200 patients were diagnosed with oesophageal and gastric cancer in England and Wales, of whom 37 % underwent planned curative treatments. Potentially curative surgical resection is associated with significant morbidity and mortality. For operable locally advanced disease, neoadjuvant chemotherapy (NAC) improves survival over surgery alone. However, NAC carries the risk of toxicity and is associated with a decrease in physical fitness, which may in turn influence subsequent clinical outcome. Lower levels of physical fitness are associated with worse outcome following major surgery in general and Upper Gastrointestinal Surgery (UGI) surgery in particular. Cardiopulmonary exercise testing (CPET) provides an objective assessment of physical fitness. The aim of this study is to test the hypothesis that NAC prior to upper gastrointestinal cancer surgery is associated with a decrease in physical fitness and that the magnitude of the change in physical fitness will predict mortality 1 year following surgery.

Methods

This study is a multi-centre, prospective, blinded, observational cohort study of participants with oesophageal and gastric cancer scheduled for neoadjuvant cancer treatment (chemo- and chemoradiotherapy) and surgery. The primary endpoints are physical fitness (oxygen uptake at lactate threshold measured using CPET) and 1-year mortality following surgery; secondary endpoints include post-operative morbidity (Post-Operative Morbidity Survey (POMS)) 5 days after surgery and patient related quality of life (EQ-5D-5 L).

Discussion

The principal benefits of this study, if the underlying hypothesis is correct, will be to facilitate better selection of treatments (e.g. NAC, Surgery) in patients with oesophageal or gastric cancer. It may also be possible to develop new treatments to reduce the effects of neoadjuvant cancer treatment on physical fitness. These results will contribute to the design of a large, multi-centre trial to determine whether an in-hospital exercise-training programme that increases physical fitness leads to improved overall survival.

Trial registration

ClinicalTrials.gov NCT01325883 - 29^th March 2011.

A double blind community-based randomized trial of amoxicillin versus placebo for fast breathing pneumonia in children aged 2-59 months in Karachi, Pakistan (RETAPP)

BACKGROUND

Fast breathing pneumonia is characterized by tachypnoea in the absence of danger signs and is mostly viral in etiology. Current guidelines recommend antibiotic therapy for all children with fast breathing pneumonia in resource limited settings, presuming that most pneumonia is bacterial. High quality clinical trial evidence to challenge or support the continued use of antibiotics, as recommended by the World Health Organization is lacking.

METHODS/DESIGN

This is a randomized double blinded placebo-controlled non-inferiority trial using parallel assignment with 1:1 allocation ratio, to be conducted in low income squatter settlements of urban Karachi, Pakistan. Children 2-59 months old with fast breathing, without any WHO-defined danger signs and seeking care at the primary health care center are randomized to receive either three days of placebo or amoxicillin. From prior studies, a sample size of 2430 children is required over a period of 28 months. Primary outcome is the difference in cumulative treatment failure between the two groups, defined as a new clinical sign based on preset definitions indicating illness progression or mortality and confirmed by two independent primary health care physicians on day 0, 1, 2 or 3 of therapy. Secondary outcomes include relapse measured between days 5-14. Modified per protocol analysis comparing hazards of treatment failure with 95% confidence intervals in the placebo arm with hazards in the amoxicillin arm will be done.

DISCUSSION

This study will provide evidence to support or refute the use of antibiotics for fast breathing pneumonia paving a way for guideline change.

TRIAL REGISTRATION

Clinical Trials (NIH) Register NCT02372461.

Use of IOTA simple rules for diagnosis of ovarian cancer: meta-analysis

OBJECTIVES

To present data on prospective evaluation of the International Ovarian Tumor Analysis (IOTA) 'simple-rules' tool for the diagnosis of ovarian cancer and to perform a meta-analysis of studies that utilized the same diagnostic method.

METHODS

In the present study a level-II ultrasound operator systematically assessed the tumors of women with an ultrasound diagnosis of adnexal tumor(s) according to the IOTA simple-rules protocol to determine the risk of the tumor being malignant. The results of simple rules were compared with the 'pattern recognition' method and with histological findings. This validation study was included in the subsequent meta-analysis, for which we searched MEDLINE, EMBASE and Cochrane from the publication of the first study in 2008. The terms used were 'simple rules', 'simple rules ovarian', 'ovar tumor' and 'ultrasound'. Quality assessment was performed using the modified Quality Assessment of the Diagnostic Accuracy of Studies (QUADAS-2) checklist. Random effects meta-analysis was used to calculate pooled estimates of sensitivity and specificity for the simple-rules tool, and meta-regression was used to investigate heterogeneity across the studies.

RESULTS

Three hundred and three women were included in the validation study with 168 (55.4%) benign, 19 (6.3%) borderline and 116 (38.3%) malignant tumors on histological examination. The rules were applicable in 237 (78.2%) of the tumors and for these tumors, sensitivity was 96.2% (95% CI, 90.5-99.0%) and specificity was 88.6% (95% CI, 82.0-93.5%). Six of the 88 discovered studies were included in the meta-analysis along with the current validation study, which resulted in inclusion of a total of 3568 patients. When the meta-analysis was performed the pooled sensitivity (when the rules were applicable) was 93% (95% CI, 90-96%) (I(2)  = 32.1%) and the pooled specificity was 95% (95% CI, 93-97%) (I(2)  = 78.1%). Heterogeneity was observed across the studies. Sensitivity was higher and specificity lower in the study populations in which the prevalence of malignant tumors was greatest.

CONCLUSION

The simple rules protocol could be used in 76-89% of tumors and is an accurate test for the diagnosis of ovarian cancer. Assessment by an ultrasound expert is required when the protocol cannot be applied.

PedVacc 002: a phase I/II randomized clinical trial of MVA.HIVA vaccine administered to infants born to human immunodeficiency virus type 1-positive mothers in Nairobi

BACKGROUND

A safe, effective vaccine for breastfeeding infants born to HIV-1-positive mothers could complement antiretroviral therapy (ART) for prevention of mother-to-child transmission of HIV-1. To date, only a few HIV-1 vaccine candidates have been tested in infants.

TRIAL DESIGN

A phase I/II randomized controlled trial PedVacc 002 was conducted to determine the safety and immunogenicity of a single, low dose of MVA.HIVA vaccine delivered intramuscularly to healthy 20-week-old infants born to HIV-1-positive mothers in Nairobi, Kenya.

METHODS

Pregnant HIV-1-positive women in the 2nd/3rd trimester of gestation were enrolled, provided with ART and self-selected their infant-feeding modality. Infants received nevirapine and cotrimoxazole prophylaxis. At 20 weeks of age, eligible HIV-1-negative infants were randomized to vaccine versus no-treatment arms and followed to 48 weeks of age for assessments of vaccine safety, HIV-1-specific T-cell responses and antibodies to routine childhood vaccines.

RESULTS

Between February and November 2010, 182 mothers were screened, 104 were eligible and followed on ART during pregnancy/postpartum, of whom 73 had eligible infants at 20 weeks postpartum. Thirty-six infants were randomized to vaccine and 37 to no treatment. Eighty-four percent of infants breastfed, and retention at 48 weeks was 99%. Adverse events were rare and similar between the two arms. HIV-1-specific T-cell frequencies in interferon-γ ELISPOT assay were transiently higher in the MVA.HIVA arm (p=0.002), but not above the threshold for a positive assay. Protective antibody levels were adequate and similar between arms for all routine childhood vaccines except HBV, where 71% of MVA.HIVA subjects compared to 92% of control subjects were protected (p=0.05).

CONCLUSIONS

This trial tested for the first time an MVA-vectored candidate HIV-1 vaccine in HIV-1-exposed infants in Africa, demonstrating trial feasibility and vaccine safety, low immunogenicity, and compatibility with routine childhood vaccinations. These results are reassuring for use of the MVA vector in more potent prime-boost regimens.

The effect of neoadjuvant chemotherapy on physical fitness and survival in patients undergoing oesophagogastric cancer surgery

BACKGROUND

Neoadjuvant chemotherapy (NAC) followed by surgery for resectable oesophageal or gastric cancer improves outcome when compared with surgery alone. However NAC has adverse effects. We assess here whether NAC adversely affects physical fitness and whether such an effect is associated with impaired survival following surgery.

METHODS

We prospectively studied 116 patients with oesophageal or gastric cancer to assess the effect of NAC on physical fitness, of whom 89 underwent cardiopulmonary exercise testing (CPET) before NAC and proceeded to surgery. 39 patients were tested after all cycles of NAC but prior to surgery. Physical fitness was assessed by measuring oxygen uptake (VO₂ in ml kg(-1) min(-1)) at the estimated lactate threshold (θL) and at peak exercise (VO₂ peak in ml kg(-1) min(-1)).

RESULTS

VO₂ at θL and at peak were significantly lower after NAC compared to pre-NAC values: VO₂ at θL 14.5 ± 3.8 (baseline) vs. 12.3 ± 3.0 (post-NAC) ml kg(-1) min(-1); p ≤ 0.001; VO₂ peak 20.8 ± 6.0 vs. 18.3 ± 5.1 ml kg(-1) min(-1); p ≤ 0.001; absolute VO₂ (ml min(-1)) at θL and peak were also lower post-NAC; p ≤ 0.001. Decreased baseline VO₂ at θL and peak were associated with increased one year mortality in patients who completed a full course of NAC and had surgery; p = 0.014.

CONCLUSION

NAC before cancer surgery significantly reduced physical fitness in the overall cohort. Lower baseline fitness was associated with reduced one-year-survival in patients completing NAC and surgery, but not in patients who did not complete NAC. It is possible that in some patients the harms of NAC may outweigh the benefits. Trials Registry Number: NCT01335555.

The effect of neoadjuvant chemotherapy on physical fitness and survival in patients undergoing oesophagogastric cancer surgery

BACKGROUND

Neoadjuvant chemotherapy (NAC) followed by surgery for resectable oesophageal or gastric cancer improves outcome when compared with surgery alone. However NAC has adverse effects. We assess here whether NAC adversely affects physical fitness and whether such an effect is associated with impaired survival following surgery.

METHODS

We prospectively studied 116 patients with oesophageal or gastric cancer to assess the effect of NAC on physical fitness, of whom 89 underwent cardiopulmonary exercise testing (CPET) before NAC and proceeded to surgery. 39 patients were tested after all cycles of NAC but prior to surgery. Physical fitness was assessed by measuring oxygen uptake (VO₂ in ml kg(-1) min(-1)) at the estimated lactate threshold (θL) and at peak exercise (VO₂ peak in ml kg(-1) min(-1)).

RESULTS

VO₂ at θL and at peak were significantly lower after NAC compared to pre-NAC values: VO₂ at θL 14.5 ± 3.8 (baseline) vs. 12.3 ± 3.0 (post-NAC) ml kg(-1) min(-1); p ≤ 0.001; VO₂ peak 20.8 ± 6.0 vs. 18.3 ± 5.1 ml kg(-1) min(-1); p ≤ 0.001; absolute VO₂ (ml min(-1)) at θL and peak were also lower post-NAC; p ≤ 0.001. Decreased baseline VO₂ at θL and peak were associated with increased one year mortality in patients who completed a full course of NAC and had surgery; p = 0.014.

CONCLUSION

NAC before cancer surgery significantly reduced physical fitness in the overall cohort. Lower baseline fitness was associated with reduced one-year-survival in patients completing NAC and surgery, but not in patients who did not complete NAC. It is possible that in some patients the harms of NAC may outweigh the benefits. Trials Registry Number: NCT01335555.

Early elevation of albumin excretion rate is associated with poor gluten-free diet adherence in young people with coeliac disease and diabetes

AIMS

There are conflicting data on microvascular complications in coexisting Type 1 diabetes and coeliac disease. We compared complications rates in youth with or without coeliac disease and examined the association between gluten-free diet adherence and complications.

METHODS

This was a comparative study of adolescents (2510 without coeliac disease, 129 with coeliac disease); 60 (47%) did not adhere to a gluten-free diet--defined as elevated anti-tissue transglutaminase or endomysial immunoglobulin A titres. Retinopathy was detected using 7-field fundal photography and albumin excretion rate by timed overnight urine collections, with early elevation defined as albumin excretion rate ≥ 7.5 μg/min. Logistic regression was used to examine the association between complications and explanatory variables, including coeliac disease vs. no coeliac disease, gluten-free diet adherence vs. non-adherence, diabetes duration and HbA1c .

RESULTS

Median age at last assessment was 16.5 years. Those with coeliac disease vs. those without were younger at diabetes diagnosis (7.1 vs. 8.6 years, P < 0.001) and had longer diabetes duration (9.3 vs. 7.2 years, P < 0.001). HbA1c was lower in those with coeliac disease vs. those without (67 vs. 70 mmol/mol, 8.3 vs. 8.6%, P = 0.04) and adherence to a gluten-free diet vs. non-adherence (66 vs. 72 mmol/mol, 8.2 vs. 8.7%, P = 0.003). There were no differences in complication rates between those with coeliac disease vs. those without (retinopathy 22 vs. 23%, elevated albumin excretion rate 31 vs. 28%). Non-adherence to a gluten-free diet was associated with elevated albumin excretion rate (40 vs. 23%, P = 0.04). In multivariable logistic regression, elevated albumin excretion rate was associated with non-adherence to a gluten-free diet (odds ratio 2.37, 95% CI 1.04-5.40, P = 0.04) and diabetes duration (odds ratio 1.13, 95% CI 1.02-1.25, P = 0.03), but not HbA1c .

CONCLUSIONS

While glycaemic control is better in patients with coeliac disease, non-adherence to a gluten-free diet is associated with elevated albumin excretion rate. The possible protection of a gluten-free diet on complications warrants further investigation.

Correlates and outcomes of preterm birth, low birth weight, and small for gestational age in HIV-exposed uninfected infants

BACKGROUND

Preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA) contribute to neonatal mortality. Maternal HIV-1 infection has been associated with an increased risk of PTB, but mechanisms underlying this association are undefined. We describe correlates and outcomes of PTB, LBW, and SGA in HIV-exposed uninfected infants.

METHODS

This was a retrospective analysis of cohort study. Between 1999-2002, pregnant, HIV-infected women were enrolled into an HIV-1 transmission study. Logistic regression was used to identify correlates of PTB, LBW and SGA in HIV-negative, spontaneous singleton deliveries. Associations between birth outcomes and mortality were measured using survival analyses.

RESULTS

In multivariable models, maternal plasma (OR = 2.1, 95% CI = 1.1-3.8) and cervical HIV-1 RNA levels (OR = 1.6, 95% CI = 1.1-2.4), and CD4 < 15% (OR = 2.4, 95% CI = 1.0-5.6) were associated with increased odds of PTB. Abnormal vaginal discharge and cervical polymorphonuclear leukocytes were also associated with PTB. Cervical HIV-1 RNA level (OR = 2.4, 95% CI = 1.5-6.7) was associated with an increased odds of LBW, while increasing parity (OR = 0.46, 95% CI = 0.24-0.88) was associated with reduced odds. Higher maternal body mass index (OR = 0.75, 95% CI = 0.61-0.92) was associated with a reduced odds of SGA, while bacterial vaginosis was associated with >3-fold increased odds (OR = 3.2, 95% CI = 1.4-7.4). PTB, LBW, and SGA were each associated with a >6-fold increased risk of neonatal death, and a >2-fold increased rate of infant mortality within the first year.

CONCLUSIONS

Maternal plasma and cervical HIV-1 RNA load, and genital infections may be important risk factors for PTB in HIV-exposed uninfected infants. PTB, LBW, and SGA are associated with increased neonatal and infant mortality in HIV-exposed uninfected infants.

Infant Neutropenia Associated with Breastfeeding During Maternal Antiretroviral Treatment for Prevention of Mother-to-Child Transmission of HIV

Maternal antiretroviral treatment (ART) is recommended for prevention of mother-to-child HIV-1 transmission (PMTCT), including in women with high CD4⁺ cell counts. Within a pediatric HIV-1 vaccine trial PedVacc 002, we assessed hematologic profiles of infants born to mothers receiving ART. All mothers had CD4⁺ cell counts of >350 mm⁻³; 93% received zidovudine-containing ART; infants received nevirapine up to 6 weeks and cotrimoxazole after 6 weeks. Among 84 infants at 19 weeks, 58% had hematologic toxicity; 44% had neutropenia and 23% had anemia. Breastfeeding was associated with 3.8-fold higher risk of neutropenia (RR 3.8, 95% CI 1.03–14.1, p = 0.008). Hematologic monitoring and PMTCT regimen selection are important for optimizing infant outcomes.

A phase I randomized clinical trial of candidate human immunodeficiency virus type 1 vaccine MVA.HIVA administered to Gambian infants

BACKGROUND

A vaccine to decrease transmission of human immunodeficiency virus type 1 (HIV-1) during breast-feeding would complement efforts to eliminate infant HIV-1 infection by antiretroviral therapy. Relative to adults, infants have distinct immune development, potentially high-risk of transmission when exposed to HIV-1 and rapid progression to AIDS when infected. To date, there have been only three published HIV-1 vaccine trials in infants.

TRIAL DESIGN

We conducted a randomized phase I clinical trial PedVacc 001 assessing the feasibility, safety and immunogenicity of a single dose of candidate vaccine MVA.HIVA administered intramuscularly to 20-week-old infants born to HIV-1-negative mothers in The Gambia.

METHODS

Infants were followed to 9 months of age with assessment of safety, immunogenicity and interference with Expanded Program on Immunization (EPI) vaccines. The trial is the first stage of developing more complex prime-boost vaccination strategies against breast milk transmission of HIV-1.

RESULTS

From March to October 2010, 48 infants (24 vaccine and 24 no-treatment) were enrolled with 100% retention. The MVA.HIVA vaccine was safe with no difference in adverse events between vaccinees and untreated infants. Two vaccine recipients (9%) and no controls had positive ex vivo interferon-γ ELISPOT assay responses. Antibody levels elicited to the EPI vaccines, which included diphtheria, tetanus, whole-cell pertussis, hepatitis B virus, Haemophilus influenzae type b and oral poliovirus, reached protective levels for the vast majority and were similar between the two arms.

CONCLUSIONS

A single low-dose of MVA.HIVA administered to 20-week-old infants in The Gambia was found to be safe and without interference with the induction of protective antibody levels by EPI vaccines, but did not alone induce sufficient HIV-1-specific responses. These data support the use of MVA carrying other transgenes as a boosting vector within more complex prime-boost vaccine strategies against transmission of HIV-1 and/or other infections in this age group.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00982579. The Pan African Clinical Trials Registry PACTR2008120000904116.

The relationship between happiness and intelligent quotient: the contribution of socio-economic and clinical factors

BACKGROUND

Happiness and higher intelligent quotient (IQ) are independently related to positive health outcomes. However, there are inconsistent reports about the relationship between IQ and happiness. The aim was to examine the association between IQ and happiness and whether it is mediated by social and clinical factors. Method The authors analysed data from the 2007 Adult Psychiatric Morbidity Survey in England. The participants were adults aged 16 years or over, living in private households in 2007. Data from 6870 participants were included in the study. Happiness was measured using a validated question on a three-point scale. Verbal IQ was estimated using the National Adult Reading Test and both categorical and continuous IQ was analysed.

RESULTS

Happiness is significantly associated with IQ. Those in the lowest IQ range (70-99) reported the lowest levels of happiness compared with the highest IQ group (120-129). Mediation analysis using the continuous IQ variable found dependency in activities of daily living, income, health and neurotic symptoms were strong mediators of the relationship, as they reduced the association between happiness and IQ by 50%.

CONCLUSIONS

Those with lower IQ are less happy than those with higher IQ. Interventions that target modifiable variables such as income (e.g. through enhancing education and employment opportunities) and neurotic symptoms (e.g. through better detection of mental health problems) may improve levels of happiness in the lower IQ groups.

Functional characterization of a heterozygous GLI2 missense mutation in patients with multiple pituitary hormone deficiency

CONTEXT

The GLI2 transcription factor is a major effector protein of the sonic hedgehog pathway and suggested to play a key role in pituitary development. Genomic GLI2 aberrations that mainly result in truncated proteins have been reported to cause holoprosencephaly or holoprosencephaly-like features, sometimes associated with hypopituitarism.

OBJECTIVE

Our objective was to determine the frequency of GLI2 mutations in patients with multiple pituitary hormone deficiency (MPHD).

DESIGN

Patients were selected from participants in the Genetics and Neuroendocrinology of Short Stature International Study (GeNeSIS) program. Patients with mutations within established candidate genes were excluded.

PATIENTS

A total of 165 patients with MPHD defined as GH deficiency and at least 1 additional pituitary hormone deficiency were studied regardless of the presence of extrapituitary clinical manifestations.

MAIN OUTCOME MEASURES

Prevalence of GLI2 variations in MPHD patients was assessed and detailed phenotypic characterization is given. Transcriptional activity of identified GLI2 variants was evaluated by functional reporter assays.

RESULTS

In 5 subjects, 4 heterozygous missense variants were identified, of which 2 are unpublished so far. One variant, p.R516P, results in vitro in a complete loss of protein function. In addition to GH deficiency, the carrier of the mutation demonstrates deficiency of thyrotrope and gonadotrope function, a maldescended posterior pituitary lobe, and polydactyly, but no midline defects.

CONCLUSIONS

For the first time, we show that heterozygous amino acid substitutions within GLI2 may lead to MPHD with mild extrapituitary findings. The phenotype of GLI2 mutations is variable, and penetrance is incomplete. GLI2 mutations are associated with anterior pituitary hypoplasia, and frequently, ectopy of the posterior lobe occurs.

MAPPED study design: a 6 month randomised controlled study to evaluate the effect of dutasteride on prostate cancer volume using magnetic resonance imaging

OBJECTIVE

To evaluate the percentage change in volume of prostate cancer, as assessed by T2-weighted MRI, following exposure to dutasteride (Avodart) 0.5mg daily for six months.

PATIENTS AND METHODS

MRI in Primary Prostate cancer after Exposure to Dutasteride (MAPPED) is a double-blind, placebo-controlled trial, supported by GlaxoSmithKline (GSK). Men with prostate cancer suitable for active surveillance (low-intermediate risk prostate cancer on biopsy), and a visible lesion on T2-weighted MRI of at least 0.2 cc, were eligible for consideration. Forty-two men were randomised to 6 months of daily dutasteride 0.5mg or placebo. Multi-parametric MRI (mpMRI) scans were performed at baseline, 3 and 6 months. The percentage changes in cancer volume over time will be compared between the dutasteride and placebo groups. Planned analyses will examine the association between tumour volume and characteristics (perfusion and contrast washout) as seen on mpMRI, HistoScan ultrasound and biopsy histopathology in both groups.

DISCUSSION

MAPPED is the first randomised controlled trial to use mpMRI to look at the effect of dutasteride on the volume of prostate cancer. If dutasteride is shown to reduce the volume of prostate cancer, it might be considered as an adjunct for men on active surveillance. Analysis of the placebo arm will allow us to comment on the short-term natural variability of the MR appearance in men who are not receiving any treatment.

CONCLUSION

MAPPED will evaluate the short-term effect of dutasteride on prostate cancer volume, as assessed by mpMRI, in men undergoing active surveillance for low or intermediate risk prostate cancer. The study completed recruitment in January 2012.

Coeliac disease in Type 1 diabetes from 1990 to 2009: higher incidence in young children after longer diabetes duration

AIMS

To determine the incidence of coeliac disease in young people with Type 1 diabetes and to examine the effect of age at diabetes onset and disease duration.

METHODS

This was a clinic-based observational cohort study of 4379 people aged ≤ 18 years (49% male) between 1990 and 2009 from Sydney, Australia. Screening for coeliac disease was performed at diagnosis and 1-2 yearly using anti-endomysial and/or anti-tissue transglutaminase immunoglobulin A (IgA) antibodies. Coeliac disease was diagnosed by small bowel biopsy based on Marsh score ≥ III.

RESULTS

Coeliac disease was confirmed by biopsy in 185; of these, 61 (33%) were endomysial or tissue transglutaminase IgA antibody-positive at diabetes diagnosis. Mean age at diabetes onset was 6.6 ± 4.0 vs. 8.4 ± 4.1 years in those without coeliac disease (P < 0.001). Mean incidence was 7.7 per 1000 person years (95% CI 6.6-8.9) over 20 years. Incidence was higher in children aged < 5 years at diabetes diagnosis (10.4 per 1000 person years) vs. ≥ 5 years (6.4 per 1000), incidence rate ratio 1.6 (95% CI 1.2-2.2, P = 0.002). Coeliac disease was diagnosed after 2, 5 and 10 years of diabetes in 45, 78 and 94% of cases, respectively. Median time to coeliac disease diagnosis was longer in children aged < 5 years at diabetes onset (3.3 years) compared with older children (0.7 years, P < 0.001).

CONCLUSIONS

Coeliac disease is common in young people with Type 1 diabetes; the risk is greatest with diabetes onset < 5 years, but after longer diabetes duration. Screening for coeliac disease should be performed at diabetes diagnosis and for at least 10 years in young children.

Prospective evaluation of the IOTA logistic regression model LR2 for the diagnosis of ovarian cancer

OBJECTIVES

To assess the accuracy of the IOTA logistic regression model LR2 for the diagnosis of ovarian cancer.

METHODS

This was a prospective single-center study of women with an ultrasound diagnosis of an adnexal tumor. They were all examined by a single Level-II ultrasound operator, who had received training in the systematic examination of ovarian tumors in accordance with the IOTA guidelines. In all women the likelihood of the adnexal lesion being malignant was calculated using the IOTA LR2 model. All women underwent surgery within 120 days of ultrasound examination and the ultrasound findings were compared with operative findings and the final histological diagnosis.

RESULTS

One hundred and twenty-four women were included in the final analysis. The mean age was 53.2 (range, 20-91) years and 61/124 (49.2%) women were postmenopausal. 66/124 (53.2%) women had malignant lesions on postoperative histological examination. The IOTA LR2 model had a sensitivity of 97.0% (95% CI, 89.5-99.6%) and a specificity of 69.0% (95% CI, 55.5-80.5%). The area under the receiver-operating characteristics curve was 0.93 (SE, 0.022; 95% CI, 0.89-0.97), which was not significantly different from 0.92 (SE, 0.018) reported in the original study (P > 0.05).

CONCLUSION

When evaluated prospectively, the accuracy of the IOTA LR2 model was similar to that reported in the original study.

The prognostic value of pre-operative predicted forced vital capacity in corrective spinal surgery for Duchenne's muscular dystrophy

The majority of patients with Duchenne's muscular dystrophy require corrective spinal surgery for scoliosis to maintain seated balance and to slow the progression of respiratory compromise, thereby facilitating nursing and enhancing their quality of life. Traditionally patients with a pre-operative forced vital capacity (PFVC) of 30% or below predicted have been denied this surgery as it was thought that the incidence of postoperative complications was unacceptably high. We present data collected prospectively from 45 consecutive operations undertaken in our unit. These cases indicate that there is no clinically significant difference in operative and postoperative outcomes between patients with PFVC > 30% and < or =30%. However, the routine postoperative use of mask ventilation to facilitate early tracheal extubation is vital.

Ethnic group differences in overweight and obese children and young people in England: cross sectional survey

AIMS

To determine the percentage of children and young adults who are obese or overweight within different ethnic and socioeconomic groups.

METHODS

Secondary analysis of data on 5689 children and young adults aged 2-20 years from the 1999 Health Survey for England.

RESULTS

Twenty three per cent of children (n = 1311) were overweight, of whom 6% (n = 358) were obese. More girls than boys were overweight (24% v 22%). Afro-Caribbean girls were more likely to be overweight (odds ratio 1.73, 95% CI 1.29 to 2.33), and Afro-Caribbean and Pakistani girls were more likely to be obese than girls in the general population (odds ratios 2.74 (95% CI 1.74 to 4.31) and 1.71 (95% CI 1.06 to 2.76), respectively). Indian and Pakistani boys were more likely to be overweight (odds ratios 1.55 (95% CI 1.12 to 2.17) and 1.36 (95% CI 1.01 to 1.83), respectively). There were no significant differences in the prevalence of obese and overweight children from different social classes.

CONCLUSION

The percentage of children and young adults who are obese and overweight differs by ethnic group and sex, but not by social class. British Afro-Caribbean and Pakistani girls have an increased risk of being obese and Indian and Pakistani boys have an increased risk of being overweight than the general population. These individuals may be at greater combined cumulative risk of morbidity and mortality from cardiovascular disease and so may be a priority for initiatives to target groups of children at particular risk of obesity.

An evaluation of existing risk stratification models as a tool for comparison of surgical performances for coronary artery bypass grafting between institutions

OBJECTIVE

Risk stratification systems are used in cardiac surgery to estimate mortality risk for individual patients and to compare surgical performance between institutions or surgeons. This study investigates the suitability of six existing risk stratification systems for these purposes.

METHODS

Data on 5471 patients who underwent isolated coronary artery bypass grafting at two UK cardiac centres between 1993 and 1999 were extracted from a prospective computerised clinical data base. Of these patients, 184 (3.3%) died in hospital. In-hospital mortality risk scores were calculated for each patient using the Parsonnet score, the EuroSCORE, the ACC/AHA score and three UK Bayes models (old, new complex and new simple). The accuracy for predicting mortality at an institutional level was assessed by comparing total observed and predicted mortality. The accuracy of the risk scores for predicting mortality for a patient was assessed by the Hosmer-Lemeshow test. The receiver operating characteristic (ROC) curve was used to evaluate how well a system ranks the patient with respect to their risk of mortality and can be useful for patient management.

RESULTS

Both EuroSCORE and the simple Bayes model were reasonably accurate at predicting overall mortality. However predictive accuracy at the patient level was poor for all systems, although EuroSCORE was accurate for low to medium risk patients. Discrimination was fair with the following ROC areas: Parsonnet 0.73, EuroSCORE 0.76, ACC/AHA system 0.76, old Bayes 0.77, complex Bayes 0.76, simple Bayes 0.76.

CONCLUSIONS

This study suggests that two of the scores may be useful in comparing institutions. None of the risk scores provide accurate risk estimates for individual patients in the two hospitals studied although EuroSCORE may have some utility for certain patients. All six systems perform moderately at ranking the patients and so may be useful for patient management. More results are needed from other institutions to confirm that the EuroSCORE and the simple Bayes model are suitable for institutional risk-adjusted comparisons.

Validation of four different risk stratification systems in patients undergoing off-pump coronary artery bypass surgery: a UK multicentre analysis of 2223 patients

BACKGROUND

Various risk stratification systems have been developed in coronary artery bypass graft surgery (CABG), based mainly on patients undergoing procedures with cardiopulmonary bypass.

OBJECTIVE

To assess the validity and applicability of the Parsonnet score, the EuroSCORE, the American College of Cardiology/American Heart Association (ACC/AHA) system, and the UK CABG Bayes model in patients undergoing off-pump coronary artery bypass surgery (OPCAB) in the UK.

METHODS

Data on 2223 patients who underwent OPCAB in eight cardiac surgical centres were collected. Predicted mortality risk scores were calculated using the four systems and compared with observed mortality. Calibration was assessed by the Hosmer-Lemeshow (HL) test. Discrimination was assessed using the receiver operating characteristic (ROC) curve area.

RESULTS

30 of 2223 patients (1.3%) died in hospital. For the Parsonnet score the HL test was significant (p < 0.001) and the receiver operating characteristic curve (ROC) area was 0.74. For the EuroSCORE the HL test was also significant (p = 0.008) and the ROC area was 0.75. For the ACC/AHA system the HL test was non-significant (p = 0.7) and the ROC area was 0.75. For the UK CABG Bayes model the HL test was also non-significant (p = 0.3) and the ROC area was 0.81.

CONCLUSIONS

The UK CABG Bayes model is reasonably well calibrated and provides good discrimination when applied to OPCAB patients in the UK. Among the other three systems, the ACC/AHA system is well calibrated but its discrimination power was less than for the UK CABG Bayes model. These data suggest that the UK CABG Bayes model could be an appropriate risk stratification system to use for patients undergoing OPCAB in the UK.

A variant microcephalic osteodysplastic slender-bone disorder with growth hormone deficiency and a pigmentary retinopathy

We present the case of a 3-year-old boy with post-natal growth failure, microcephaly, developmental delay, facial dysmorphism, an evolving pigmentary retinopathy, pituitary hypoplasia, micropenis, and growth hormone (GH) deficiency. He has a microcephalic osteodysplastic slender-bone disorder with disharmonic delayed osseous maturation, most closely resembling patients with microcephalic osteodysplastic primordial dwarfism type II (MOPD II). Intrauterine growth retardation, a universal finding in the MOPD II, was absent in our patient.

The use of fractional polynomials to model continuous risk variables in epidemiology

BACKGROUND

The traditional method of analysing continuous or ordinal risk factors by categorization or linear models may be improved.

METHODS

We propose an approach based on transformation and fractional polynomials which yields simple regression models with interpretable curves. We suggest a way of presenting the results from such models which involves tabulating the risks estimated from the model at convenient values of the risk factor. We discuss how to incorporate several continuous risk and confounding variables within a single model. The approach is exemplified with data from the Whitehall I study of British Civil Servants. We discuss the approach in relation to categorization and non-parametric regression models.

RESULTS

We show that non-linear risk models fit the data better than linear models. We discuss the difficulties introduced by categorization and the advantages of the new approach.

CONCLUSIONS

Our approach based on fractional polynomials should be considered as an important alternative to the traditional approaches for the analysis of continuous variables in epidemiological studies.