Association between pre-biologic T2-biomarker combinations and response to biologics in patients with severe asthma

Background

To date, studies investigating the association between pre-biologic biomarker levels and post-biologic outcomes have been limited to single biomarkers and assessment of biologic efficacy from structured clinical trials.

Aim

To elucidate the associations of pre-biologic individual biomarker levels or their combinations with pre-to-post biologic changes in asthma outcomes in real-life.

Methods

This was a registry-based, cohort study using data from 23 countries, which shared data with the International Severe Asthma Registry (May 2017-February 2023). The investigated biomarkers (highest pre-biologic levels) were immunoglobulin E (IgE), blood eosinophil count (BEC) and fractional exhaled nitric oxide (FeNO). Pre- to approximately 12-month post-biologic change for each of three asthma outcome domains (i.e. exacerbation rate, symptom control and lung function), and the association of this change with pre-biologic biomarkers was investigated for individual and combined biomarkers.

Results

Overall, 3751 patients initiated biologics and were included in the analysis. No association was found between pre-biologic BEC and pre-to-post biologic change in exacerbation rate for any biologic class. However, higher pre-biologic BEC and FeNO were both associated with greater post-biologic improvement in FEV1 for both anti-IgE and anti-IL5/5R, with a trend for anti-IL4Rα. Mean FEV1 improved by 27-178 mL post-anti-IgE as pre-biologic BEC increased (250 to 1000 cells/µL), and by 43-216 mL and 129-250 mL post-anti-IL5/5R and -anti-IL4Rα, respectively along the same BEC gradient. Corresponding improvements along a FeNO gradient (25-100 ppb) were 41-274 mL, 69-207 mL and 148-224 mL for anti-IgE, anti-IL5/5R, and anti-IL4Rα, respectively. Higher baseline BEC was also associated with lower probability of uncontrolled asthma (OR 0.392; p=0.001) post-biologic for anti-IL5/5R. Pre-biologic IgE was a poor predictor of subsequent pre-to-post-biologic change for all outcomes assessed for all biologics. The combination of BEC + FeNO marginally improved the prediction of post-biologic FEV1 increase (adjusted R2: 0.751), compared to BEC (adjusted R2: 0.747) or FeNO alone (adjusted R2: 0.743) (p=0.005 and <0.001, respectively); however, this prediction was not improved by the addition of IgE.

Conclusions

The ability of higher baseline BEC, FeNO and their combination to predict biologic-associated lung function improvement may encourage earlier intervention in patients with impaired lung function or at risk of accelerated lung function decline.

Ten-year survival of neoadjuvant dual HER2 blockade in patients with HER2-positive breast cancer

BACKGROUND

Dual anti-HER2-targeted therapy in breast cancer (BC) significantly increased the rate of pathological complete response (pCR) compared to single blockade when added to chemotherapy. However, limited data exist on the long-term impact on survival of the additional increase in pCR.

METHODS

Neoadjuvant lapatinib and/or trastuzumab treatment optimisation (NCT00553358) is an international, randomised, open-label, phase III study investigating the addition of lapatinib to chemotherapy plus trastuzumab in HER2-positive early BC. Ten-year event-free survival (EFS), overall survival (OS) and safety were assessed on intention-to-treat population. The association between pCR and EFS or OS was investigated in landmark population.

RESULTS

A total of 455 patients were randomised to receive lapatinib (154), trastuzumab (149) or the combination (152). Ten-year EFS estimates were 63% (95% confidence interval [CI], 54%-71%) in the lapatinib group, 64% (95% CI, 55%-72%) in the trastuzumab group and 67% (95% CI, 58%-74%) in the combination group. Ten-year OS rates were 76% (95% CI, 67%-83%), 75% (95% CI, 66%-82%) and 80% (95% CI, 73%-86%) in the lapatinib, trastuzumab and combination groups, respectively. Women who achieved a pCR had improved EFS (hazard ratio 0.48, 95% CI, 0.31-0.73) and OS (hazard ratio 0.37, 95% CI, 0.20-0.63) compared with those who did not. The numerical difference in survival according to pCR status was greater in women treated with the combination and those with hormone-receptor-negative tumours. There were no new or long-term safety concerns.

CONCLUSIONS

Patients with HER2-positive BC showed a durable survival benefit of neoadjuvant anti-HER2, irrespective of treatment arm. Patients who achieve pCR have significantly better outcomes than patients without pCR.

Planned delivery for pre-eclampsia between 34 and 37 weeks of gestation: the PHOENIX RCT

BACKGROUND

In women with late preterm pre-eclampsia (i.e. at 34+0 to 36+6 weeks' gestation), the optimal delivery time is unclear because limitation of maternal-fetal disease progression needs to be balanced against infant complications. The aim of this trial was to determine whether or not planned earlier initiation of delivery reduces maternal adverse outcomes without substantial worsening of perinatal or infant outcomes, compared with expectant management, in women with late preterm pre-eclampsia.

METHODS

We undertook an individually randomised, triple non-masked controlled trial in 46 maternity units across England and Wales, with an embedded health economic evaluation, comparing planned delivery and expectant management (usual care) in women with late preterm pre-eclampsia. The co-primary maternal outcome was a maternal morbidity composite or recorded systolic blood pressure of ≥ 160 mmHg (superiority hypothesis). The co-primary short-term perinatal outcome was a composite of perinatal deaths or neonatal unit admission (non-inferiority hypothesis). Analyses were by intention to treat, with an additional per-protocol analysis for the perinatal outcome. The primary 2-year infant neurodevelopmental outcome was measured using the PARCA-R (Parent Report of Children's Abilities-Revised) composite score. The planned sample size of the trial was 900 women; the trial is now completed. We undertook two linked substudies.

RESULTS

Between 29 September 2014 and 10 December 2018, 901 women were recruited; 450 women [448 women (two withdrew consent) and 471 infants] were allocated to planned delivery and 451 women (451 women and 475 infants) were allocated to expectant management. The incidence of the co-primary maternal outcome was significantly lower in the planned delivery group [289 (65%) women] than in the expectant management group [338 (75%) women] (adjusted relative risk 0.86, 95% confidence interval 0.79 to 0.94; p = 0.0005). The incidence of the co-primary perinatal outcome was significantly higher in the planned delivery group [196 (42%) infants] than in the expectant management group [159 (34%) infants] (adjusted relative risk 1.26, 95% confidence interval 1.08 to 1.47; p = 0.0034), but indicators of neonatal morbidity were similar in both groups. At 2-year follow-up, the mean PARCA-R scores were 89.5 points (standard deviation 18.2 points) for the planned delivery group (290 infants) and 91.9 points (standard deviation 18.4 points) for the expectant management group (256 infants), both within the normal developmental range (adjusted mean difference -2.4 points, 95% confidence interval -5.4 to 0.5 points; non-inferiority p = 0.147). Planned delivery was significantly cost-saving (-£2711, 95% confidence interval -£4840 to -£637) compared with expectant management. There were nine serious adverse events in the planned delivery group and 12 in the expectant management group.

CONCLUSION

In women with late preterm pre-eclampsia, planned delivery reduces short-term maternal morbidity compared with expectant management, with more neonatal unit admissions related to prematurity but no indicators of greater short-term neonatal morbidity (such as need for respiratory support). At 2-year follow-up, around 60% of parents reported follow-up scores. Average infant development was within the normal range for both groups; the small between-group mean difference in PARCA-R scores is unlikely to be clinically important. Planned delivery was significantly cost-saving to the health service. These findings should be discussed with women with late preterm pre-eclampsia to allow shared decision-making on timing of delivery.

LIMITATIONS

Limitations of the trial include the challenges of finding a perinatal outcome that adequately represented the potential risks of both groups and a maternal outcome that reflects the multiorgan manifestations of pre-eclampsia. The incidences of maternal and perinatal primary outcomes were higher than anticipated on the basis of previous studies, but this did not limit interpretation of the analysis. The trial was limited by a higher loss to follow-up rate than expected, meaning that the extent and direction of bias in outcomes (between responders and non-responders) is uncertain. A longer follow-up period (e.g. up to 5 years) would have enabled us to provide further evidence on long-term infant outcomes, but this runs the risk of greater attrition and increased expense.

FUTURE WORK

We identified a number of further questions that could be prioritised through a formal scoping process, including uncertainties around disease-modifying interventions, prognostic factors, longer-term follow-up, the perspectives of women and their families, meta-analysis with other studies, effect of a similar intervention in other health-care settings, and clinical effectiveness and cost-effectiveness of other related policies around neonatal unit admission in late preterm birth.

TRIAL REGISTRATION

The trial was prospectively registered as ISRCTN01879376.

FUNDING

This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in Health Technology Assessment. See the NIHR Journals Library website for further project information.

The effect of the COVID-19 pandemic on time to angiography and outcomes in patients presenting with non-ST elevation myocardial infarction

Funding Acknowledgements

Type of funding sources: None.

Background

Covid-19 pandemic has had a profound impact on healthcare service delivery. Acute cardiovascular care however remains a priority despite the pandemic. Patients presenting with non-ST elevation MI (NSTEMI) have been poorly characterised during the pandemic.

Methods

We conducted a retrospective study of patients diagnosed with NSTEMI during the peak of the pandemic between April-May 2020 at our tertiary centre in the UK. Data was collected from electronic patient clinical records including time from admission to angiography, length of stay, mortality, prescription of secondary prevention pharmacotherapy and referral to cardiac rehabilitation. We compared this data to the same time period in 2019.

Results

As can be seen from Table 1, in 2020, the mean age, median time to angiography and length of stay were all significantly lower than the control period of 2019. Prescription of secondary prevention medication (Aspirin, P2Y12 inhibitor, Beta-blocker, Statin and ACEi/ARB) and referral to cardiac rehabilitation also improved in 2020, however neither was statistically significant.

During the 2020 period, 1 patient died due to late presentation NSTEMI and multi-organ failure. There were 3 deaths in 2019: complications following coronary bypass surgery, upper GI bleed and a subarachnoid haemorrhage.

Conclusion

Our results show that the mean age of the patients presenting with NSTEMI during the peak of Covid-19 pandemic was younger suggesting that elderly patients failed to present. Compared to 2019, there was significant improvement in patient treatment times with a significantly shorter stay in hospital, probably as a result of the reduction in elective activity allowing un-restrained access to the catheter labs.  We also saw improvement in prescription for secondary prevention and referral to cardiac rehabilitation services during this time suggesting that there may have been improved focus on these aspects of care again.

Clinical Characteristics and Outcomes From Percutaneous Coronary Intervention of Last Remaining Coronary Artery

Background:

Patients with complex high-risk coronary anatomy, such as those with a last remaining patent vessel (LRPV), are increasingly revascularized with percutaneous coronary intervention (PCI) in contemporary practice. There are limited data on the outcomes of these high-risk procedures.

Methods:

We analyzed a large longitudinal PCI cohort (2007–2014, n=501 841) from the British Cardiovascular Intervention Society database. Clinical, demographic, procedural, and outcome data were analyzed by dividing patients into 2 groups; LRPV group (n=2432) and all other PCI groups (n=506 691).

Results:

Patients in the LRPV PCI group were older, had more comorbidities, and higher prevalence of moderate-severe left ventricular systolic dysfunction. Mortality was higher in the LRPV PCI group during hospital admission (12 % versus 1.5 %, P <0.001), at 30 days (15% versus 2%, P <0.001), and at one-year (24% versus 5%, P <0.001). In a propensity score matching analysis the adjusted risk of mortality during index admission (odds ratio, 2.05 [95% CI, 1.65–2.44], P <0.001), at 30 days (odds ratio, 2.13 [95% CI, 1.78–2.5], P <0.001), at 1 year (odds ratio, 1.81 [95% CI, 1.59–2.03], P <0.001), and in-hospital major adverse cardiovascular events (odds ratio, 1.8 [95% CI, 1.42–2.19], P <0.001) were higher in LRPV PCI group as compared to control group. In sensitivity analyses, similar clinical outcomes were observed irrespective of which major epicardial coronary artery was treated.

Conclusions:

In this contemporary cohort, patients who had PCI to their LRPV had a higher-risk profile and more adverse clinical outcomes, irrespective of the vessel treated.

Two speeds of increasing milk feeds for very preterm or very low-birthweight infants: the SIFT RCT

BACKGROUND

Observational data suggest that slowly advancing enteral feeds in preterm infants may reduce necrotising enterocolitis but increase late-onset sepsis. The Speed of Increasing milk Feeds Trial (SIFT) compared two rates of feed advancement.

OBJECTIVE

To determine if faster (30 ml/kg/day) or slower (18 ml/kg/day) daily feed increments improve survival without moderate or severe disability and other morbidities in very preterm or very low-birthweight infants.

DESIGN

This was a multicentre, two-arm, parallel-group, randomised controlled trial. Randomisation was via a web-hosted minimisation algorithm. It was not possible to safely and completely blind caregivers and parents.

SETTING

The setting was 55 UK neonatal units, from May 2013 to June 2015.

PARTICIPANTS

The participants were infants born at < 32 weeks' gestation or a weight of < 1500 g, who were receiving < 30 ml/kg/day of milk at trial enrolment.

INTERVENTIONS

When clinicians were ready to start advancing feed volumes, the infant was randomised to receive daily feed increments of either 30 ml/kg/day or 18 ml/kg/day. In total, 1400 infants were allocated to fast feeds and 1404 infants were allocated to slow feeds.

MAIN OUTCOME MEASURES

The primary outcome was survival without moderate or severe neurodevelopmental disability at 24 months of age, corrected for gestational age. The secondary outcomes were mortality; moderate or severe neurodevelopmental disability at 24 months corrected for gestational age; death before discharge home; microbiologically confirmed or clinically suspected late-onset sepsis; necrotising enterocolitis (Bell's stage 2 or 3); time taken to reach full milk feeds (tolerating 150 ml/kg/day for 3 consecutive days); growth from birth to discharge; duration of parenteral feeding; time in intensive care; duration of hospital stay; diagnosis of cerebral palsy by a doctor or other health professional; and individual components of the definition of moderate or severe neurodevelopmental disability.

RESULTS

The results showed that survival without moderate or severe neurodevelopmental disability at 24 months occurred in 802 out of 1224 (65.5%) infants allocated to faster increments and 848 out of 1246 (68.1%) infants allocated to slower increments (adjusted risk ratio 0.96, 95% confidence interval 0.92 to 1.01). There was no significant difference between groups in the risk of the individual components of the primary outcome or in the important hospital outcomes: late-onset sepsis (adjusted risk ratio 0.96, 95% confidence interval 0.86 to 1.07) or necrotising enterocolitis (adjusted risk ratio 0.88, 95% confidence interval 0.68 to 1.16). Cost-consequence analysis showed that the faster feed increment rate was less costly but also less effective than the slower rate in terms of achieving the primary outcome, so was therefore found to not be cost-effective. Four unexpected serious adverse events were reported, two in each group. None was assessed as being causally related to the intervention.

LIMITATIONS

The study could not be blinded, so care may have been affected by knowledge of allocation. Although well powered for comparisons of all infants, subgroup comparisons were underpowered.

CONCLUSIONS

No clear advantage was identified for the important outcomes in very preterm or very low-birthweight infants when milk feeds were advanced in daily volume increments of 30 ml/kg/day or 18 ml/kg/day. In terms of future work, the interaction of different milk types with increments merits further examination, as may different increments in infants at the extremes of gestation or birthweight.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN76463425.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 18. See the NIHR Journals Library website for further project information.

Controlled Trial of Two Incremental Milk-Feeding Rates in Preterm Infants

BACKGROUND

Observational data have shown that slow advancement of enteral feeding volumes in preterm infants is associated with a reduced risk of necrotizing enterocolitis but an increased risk of late-onset sepsis. However, data from randomized trials are limited.

METHODS

We randomly assigned very preterm or very-low-birth-weight infants to daily milk increments of 30 ml per kilogram of body weight (faster increment) or 18 ml per kilogram (slower increment) until reaching full feeding volumes. The primary outcome was survival without moderate or severe neurodevelopmental disability at 24 months. Secondary outcomes included components of the primary outcome, confirmed or suspected late-onset sepsis, necrotizing enterocolitis, and cerebral palsy.

RESULTS

Among 2804 infants who underwent randomization, the primary outcome could be assessed in 1224 (87.4%) assigned to the faster increment and 1246 (88.7%) assigned to the slower increment. Survival without moderate or severe neurodevelopmental disability at 24 months occurred in 802 of 1224 infants (65.5%) assigned to the faster increment and 848 of 1246 (68.1%) assigned to the slower increment (adjusted risk ratio, 0.96; 95% confidence interval [CI], 0.92 to 1.01; P = 0.16). Late-onset sepsis occurred in 414 of 1389 infants (29.8%) in the faster-increment group and 434 of 1397 (31.1%) in the slower-increment group (adjusted risk ratio, 0.96; 95% CI, 0.86 to 1.07). Necrotizing enterocolitis occurred in 70 of 1394 infants (5.0%) in the faster-increment group and 78 of 1399 (5.6%) in the slower-increment group (adjusted risk ratio, 0.88; 95% CI, 0.68 to 1.16).

CONCLUSIONS

There was no significant difference in survival without moderate or severe neurodevelopmental disability at 24 months in very preterm or very-low-birth-weight infants with a strategy of advancing milk feeding volumes in daily increments of 30 ml per kilogram as compared with 18 ml per kilogram. (Funded by the Health Technology Assessment Programme of the National Institute for Health Research; SIFT Current Controlled Trials number, ISRCTN76463425.).

Planned early delivery or expectant management for late preterm pre-eclampsia (PHOENIX): a randomised controlled trial

BACKGROUND

In women with late preterm pre-eclampsia, the optimal time to initiate delivery is unclear because limitation of maternal disease progression needs to be balanced against infant complications. The aim of this trial was to determine whether planned earlier initiation of delivery reduces maternal adverse outcomes without substantial worsening of neonatal or infant outcomes, compared with expectant management (usual care) in women with late preterm pre-eclampsia.

METHODS

In this parallel-group, non-masked, multicentre, randomised controlled trial done in 46 maternity units across England and Wales, we compared planned delivery versus expectant management (usual care) with individual randomisation in women with late preterm pre-eclampsia from 34 to less than 37 weeks' gestation and a singleton or dichorionic diamniotic twin pregnancy. The co-primary maternal outcome was a composite of maternal morbidity or recorded systolic blood pressure of at least 160 mm Hg with a superiority hypothesis. The co-primary perinatal outcome was a composite of perinatal deaths or neonatal unit admission up to infant hospital discharge with a non-inferiority hypothesis (non-inferiority margin of 10% difference in incidence). Analyses were by intention to treat, together with a per-protocol analysis for the perinatal outcome. The trial was prospectively registered with the ISRCTN registry, ISRCTN01879376. The trial is closed to recruitment but follow-up is ongoing.

FINDINGS

Between Sept 29, 2014, and Dec 10, 2018, 901 women were recruited. 450 women (448 women and 471 infants analysed) were allocated to planned delivery and 451 women (451 women and 475 infants analysed) to expectant management. The incidence of the co-primary maternal outcome was significantly lower in the planned delivery group (289 [65%] women) compared with the expectant management group (338 [75%] women; adjusted relative risk 0·86, 95% CI 0·79-0·94; p=0·0005). The incidence of the co-primary perinatal outcome by intention to treat was significantly higher in the planned delivery group (196 [42%] infants) compared with the expectant management group (159 [34%] infants; 1·26, 1·08-1·47; p=0·0034). The results from the per-protocol analysis were similar. There were nine serious adverse events in the planned delivery group and 12 in the expectant management group.

INTERPRETATION

There is strong evidence to suggest that planned delivery reduces maternal morbidity and severe hypertension compared with expectant management, with more neonatal unit admissions related to prematurity but no indicators of greater neonatal morbidity. This trade-off should be discussed with women with late preterm pre-eclampsia to allow shared decision making on timing of delivery.

FUNDING

National Institute for Health Research Health Technology Assessment Programme.

Do frailty measures improve prediction of mortality and morbidity following transcatheter aortic valve implantation? An analysis of the UK TAVI registry

OBJECTIVES

Previous studies indicate frailty to be associated with poor outcomes following transcatheter aortic valve implantation (TAVI), but there is limited evidence from multicentre registries. The aim was to investigate the independent association of frailty with TAVI outcomes, and the prognostic utility of adding frailty into existing clinical prediction models (CPMs).

DESIGN

The UK TAVI registry incorporated three frailty measures since 2013: Canadian Study of Health and Ageing, KATZ and poor mobility. We investigated the associations between these frailty measures with short-term and long-term outcomes, using logistic regression to estimate multivariable adjusted ORs, and Cox proportional hazards models to explore long-term survival. We compared the predictive performance of existing TAVI CPMs before and after updating them to include each frailty measure.

SETTING

All patients who underwent a TAVI procedure in England or Wales between 2013 and 2014.

PARTICIPANTS

2624 TAVI procedures were analysed in this study.

PRIMARY AND SECONDARY OUTCOMES

The primary endpoints in this study were 30-day mortality and long-term survival. The Valve Academic Research Consortium (VARC)-2 composite early safety endpoint was considered as a secondary outcome.

RESULTS

KATZ <6 (OR 2.10, 95% CI 1.39 to 3.15) and poor mobility (OR 2.15, 95% CI 1.41 to 3.28) predicted 30-day mortality after multivariable adjustment. All frailty measures were associated with increased odds of the VARC-2 composite early safety endpoint. We observed a significant increase in the area under the receiver operating characteristic curves by approximately 5% after adding KATZ <6 or poor mobility into the TAVI CPMs. Risk stratification agreement was significantly improved by the addition of each frailty measure, with an increase in intraclass correlation coefficient of between 0.15 and 0.31.

CONCLUSION

Frailty was associated with worse outcomes following TAVI, and incorporating frailty metrics significantly improved the predictive performance of existing CPMs. Physician-estimated frailty measures could aid TAVI risk stratification, until more objective scales are routinely collected.

The association between chronic airflow obstruction and poverty in 12 sites of the multinational BOLD study

Poverty is strongly associated with mortality from COPD, but little is known of its relation to airflow obstruction.

In a cross-sectional study of adults aged ≥40 years from 12 sites (N=9255), participating in the Burden of Obstructive Lung Disease (BOLD) study, poverty was evaluated using a wealth score (0–10) based on household assets. Obstruction, measured as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) (%) after administration of 200 μg salbutamol, and prevalence of FEV1/FVC<lower limit of normal were tested for association with poverty for each site, and the results were combined by meta-analysis.

Mean wealth scores ranged from 4 in Blantyre (Malawi) and Kashmir (India) to 10 in Riyadh (Saudi Arabia), and the prevalence of obstruction, from 16% in Kashmir to 3% in Riyadh and Penang (Malaysia). Following adjustments for age and sex, FEV1/FVC increased by 0.36% (absolute change) (95%CI: 0.22, 0.49; p<0.001) per unit increase in wealth score. Adjustments for other confounders reduced this effect to 0.23% (0.11, 0.34), but even this value remained highly significant (p<0.001). Results were consistent across sites (I2=1%; phet=0.44). Mean wealth scores explained 38% of the variation in mean FEV1/FVC between sites (r2=0.385, p=0.031).

Airflow obstruction is consistently associated with poverty at individual and community levels across several countries.

Large-displacement, hydrothermal frictional properties of DFDP-1 fault rocks, Alpine Fault, New Zealand: Implications for deep rupture propagation

The Alpine Fault, New Zealand, is a major plate-bounding fault that accommodates 65-75% of the total relative motion between the Australian and Pacific plates. Here we present data on the hydrothermal frictional properties of Alpine Fault rocks that surround the principal slip zones (PSZ) of the Alpine Fault and those comprising the PSZ itself. The samples were retrieved from relatively shallow depths during phase 1 of the Deep Fault Drilling Project (DFDP-1) at Gaunt Creek. Simulated fault gouges were sheared at temperatures of 25, 150, 300, 450, and 600°C in order to determine the friction coefficient as well as the velocity dependence of friction. Friction remains more or less constant with changes in temperature, but a transition from velocity-strengthening behavior to velocity-weakening behavior occurs at a temperature of T = 150°C. The transition depends on the absolute value of sliding velocity as well as temperature, with the velocity-weakening region restricted to higher velocity for higher temperatures. Friction was substantially lower for low-velocity shearing (V < 0.3 µm/s) at 600°C, but no transition to normal stress independence was observed. In the framework of rate-and-state friction, earthquake nucleation is most likely at an intermediate temperature of T = 300°C. The velocity-strengthening nature of the Alpine Fault rocks at higher temperatures may pose a barrier for rupture propagation to deeper levels, limiting the possible depth extent of large earthquakes. Our results highlight the importance of strain rate in controlling frictional behavior under conditions spanning the classical brittle-plastic transition for quartzofeldspathic compositions.

Development of an international scale of socio-economic position based on household assets

Background

The importance of studying associations between socio-economic position and health has often been highlighted. Previous studies have linked the prevalence and severity of lung disease with national wealth and with socio-economic position within some countries but there has been no systematic evaluation of the association between lung function and poverty at the individual level on a global scale. The BOLD study has collected data on lung function for individuals in a wide range of countries, however a barrier to relating this to personal socio-economic position is the need for a suitable measure to compare individuals within and between countries. In this paper we test a method for assessing socio-economic position based on the scalability of a set of durable assets (Mokken scaling), and compare its usefulness across countries of varying gross national income per capita.

Results

Ten out of 15 candidate asset questions included in the questionnaire were found to form a Mokken type scale closely associated with GNI per capita (Spearman’s rank r_s = 0.91, p = 0.002). The same set of assets conformed to a scale in 7 out of the 8 countries, the remaining country being Saudi Arabia where most respondents owned most of the assets. There was good consistency in the rank ordering of ownership of the assets in the different countries (Cronbach’s alpha = 0.96). Scores on the Mokken scale were highly correlated with scores developed using principal component analysis (r_s = 0.977).

Conclusions

Mokken scaling is a potentially valuable tool for uncovering links between disease and socio-economic position within and between countries. It provides an alternative to currently used methods such as principal component analysis for combining personal asset data to give an indication of individuals’ relative wealth. Relative strengths of the Mokken scale method were considered to be ease of interpretation, adaptability for comparison with other datasets, and reliability of imputation for even quite large proportions of missing values.

The Birthplace in England national prospective cohort study: further analyses to enhance policy and service delivery decision-making for planned place of birth

Background

Evidence from the Birthplace in England Research Programme supported a policy of offering ‘low risk’ women a choice of birth setting, but a number of unanswered questions remained.

Aims

This project aimed to provide further evidence to support the development and delivery of maternity services and inform women’s choice of birth setting: specifically, to explore maternal and organisational factors associated with intervention, transfer and other outcomes in each birth setting in ‘low risk’ and ‘higher risk’ women.

Design

Five component studies using secondary analysis of the Birthplace prospective cohort study (studies 2–5) and ecological analysis of unit/NHS trust-level data (studies 1 and 5).

Setting

Obstetric units (OUs), alongside midwifery units (AMUs), freestanding midwifery units (FMUs) and planned home births in England.

Participants

Studies 1–4 focused on ‘low risk’ women with ‘term’ pregnancies planning vaginal birth in 43 AMUs (n = 16,573), in 53 FMUs (n = 11,210), at home in 147 NHS trusts (n = 16,632) and in a stratified, random sample of 36 OUs (n = 19,379) in 2008–10. Study 5 focused on women with pre-existing medical and obstetric risk factors (‘higher risk’ women).

Main outcome measures

Interventions (instrumental delivery, intrapartum caesarean section), a measure of low intervention (‘normal birth’), a measure of spontaneous vaginal birth without complications (‘straightforward birth’), transfer during labour and a composite measure of adverse perinatal outcome (‘intrapartum-related mortality and morbidity’ or neonatal admission within 48 hours for > 48 hours). In studies 1 and 3, rates of intervention/maternal outcome and transfer were adjusted for maternal characteristics.

Analysis

We used (a) funnel plots to explore variation in rates of intervention/maternal outcome and transfer between units/trusts, (b) simple, weighted linear regression to evaluate associations between unit/trust characteristics and rates of intervention/maternal outcome and transfer, (c) multivariable Poisson regression to evaluate associations between planned place of birth, maternal characteristics and study outcomes, and (d) logistic regression to investigate associations between time of day/day of the week and study outcomes.

Results

Study 1 – unit-/trust-level variations in rates of interventions, transfer and maternal outcomes were not explained by differences in maternal characteristics. The magnitude of identified associations between unit/trust characteristics and intervention, transfer and outcome rates was generally small, but some aspects of configuration were associated with rates of transfer and intervention. Study 2 – ‘low risk’ women planning non-OU birth had a reduced risk of intervention irrespective of ethnicity or area deprivation score. In nulliparous women planning non-OU birth the risk of intervention increased with increasing age, but women of all ages planning non-OU birth experienced a reduced risk of intervention. Study 3 – parity, maternal age, gestational age and ‘complicating conditions’ identified at the start of care in labour were independently associated with variation in the risk of transfer in ‘low risk’ women planning non-OU birth. Transfers did not vary by time of day/day of the week in any meaningful way. The duration of transfer from planned FMU and home births was around 50–60 minutes; transfers for ‘potentially urgent’ reasons were quicker than transfers for ‘non-urgent’ reasons. Study 4 – the occurrence of some interventions varied by time of the day/day of the week in ‘low risk’ women planning OU birth. Study 5 – ‘higher risk’ women planning birth in a non-OU setting had fewer risk factors than ‘higher risk’ women planning OU birth and these risk factors were different. Compared with ‘low risk’ women planning home birth, ‘higher risk’ women planning home birth had a significantly increased risk of our composite adverse perinatal outcome measure. However, in ‘higher risk’ women, the risk of this outcome was lower in planned home births than in planned OU births, even after adjustment for clinical risk factors.

Conclusions

Expansion in the capacity of non-OU intrapartum care could reduce intervention rates in ‘low risk’ women, and the benefits of midwifery-led intrapartum care apply to all ‘low risk’ women irrespective of age, ethnicity or area deprivation score. Intervention rates differ considerably between units, however, for reasons that are not understood. The impact of major changes in the configuration of maternity care on outcomes should be monitored and evaluated. The impact of non-clinical factors, including labour ward practices, staffing and skill mix and women’s preferences and expectations, on intervention requires further investigation. All women planning non-OU birth should be informed of their chances of transfer and, in particular, older nulliparous women and those more than 1 week past their due date should be advised of their increased chances of transfer. No change in the guidance on planning place of birth for ‘higher risk’ women is recommended, but research is required to evaluate the safety of planned AMU birth for women with selected relatively common risk factors.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Perinatal and maternal outcomes in planned home and obstetric unit births in women at 'higher risk' of complications: secondary analysis of the Birthplace national prospective cohort study

OBJECTIVE

To explore and compare perinatal and maternal outcomes in women at 'higher risk' of complications planning home versus obstetric unit (OU) birth.

DESIGN

Prospective cohort study.

SETTING

OUs and planned home births in England.

POPULATION

8180 'higher risk' women in the Birthplace cohort.

METHODS

We used Poisson regression to calculate relative risks adjusted for maternal characteristics. Sensitivity analyses explored possible effects of differences in risk between groups and alternative outcome measures.

MAIN OUTCOME MEASURES

Composite perinatal outcome measure encompassing 'intrapartum related mortality and morbidity' (intrapartum stillbirth, early neonatal death, neonatal encephalopathy, meconium aspiration syndrome, brachial plexus injury, fractured humerus or clavicle) and neonatal admission within 48 hours for more than 48 hours. Two composite maternal outcome measures capturing intrapartum interventions/adverse maternal outcomes and straightforward birth.

RESULTS

The risk of 'intrapartum related mortality and morbidity' or neonatal admission for more than 48 hours was lower in planned home births than planned OU births [adjusted relative risks (RR) 0.50, 95% CI 0.31-0.81]. Adjustment for clinical risk factors did not materially affect this finding. The direction of effect was reversed for the more restricted outcome measure 'intrapartum related mortality and morbidity' (RR adjusted for parity 1.92, 95% CI 0.97-3.80). Maternal interventions were lower in planned home births.

CONCLUSIONS

The babies of 'higher risk' women who plan birth in an OU appear more likely to be admitted to neonatal care than those whose mothers plan birth at home, but it is unclear if this reflects a real difference in morbidity. Rates of intrapartum related morbidity and mortality did not differ statistically significantly between settings at the 5% level but a larger study would be required to rule out a clinically important difference between the groups.

The effect of running velocity on footstrike angle--a curve-clustering approach

Despite a large number of studies that have considered footstrike pattern, relatively little is known about how runners alter their footstrike pattern with running velocity. The purpose of this study was to determine how footstrike pattern, defined by footstrike angle (FSA), is affected by running velocity in recreational athletes. One hundred and two recreational athletes ran on a treadmill at up to ten set velocities ranging from 2.2-6.1 ms(-1). Footstrike angle (positive rearfoot strike, negative forefoot strike), as well as stride frequency, normalised stride length, ground contact time and duty factor, were obtained from sagittal plane high speed video captured at 240 Hz. A probabilistic curve-clustering method was applied to the FSA data of all participants. The curve-clustering analysis identified three distinct and approximately equally sized groups of behaviour: (1) small/negative FSA throughout; (2) large positive FSA at low velocities (≤ 4 ms(-1)) transitioning to a smaller FSA at higher velocities (≥ 5 ms(-1)); (3) large positive FSA throughout. As expected, stride frequency was higher, while normalised stride length, ground contact time and duty factor were all lower for Cluster 1 compared to Cluster 3 across all velocities; Cluster 2 typically displayed intermediate values. These three clusters of FSA - velocity behaviour, and in particular the two differing trends observed in runners with a large positive FSAs at lower velocities, can provide a novel and relevant means of grouping athletes for further assessment of their running biomechanics.

Service configuration, unit characteristics and variation in intervention rates in a national sample of obstetric units in England: an exploratory analysis

OBJECTIVES

To explore whether service configuration and obstetric unit (OU) characteristics explain variation in OU intervention rates in 'low-risk' women.

DESIGN

Ecological study using funnel plots to explore unit-level variations in adjusted intervention rates and simple linear regression, stratified by parity, to investigate possible associations between unit characteristics/configuration and adjusted intervention rates in planned OU births. Characteristics considered: OU size, presence of an alongside midwifery unit (AMU), proportion of births in the National Health Service (NHS) trust planned in midwifery units or at home and midwifery 'under' staffing.

SETTING

36 OUs in England.

PARTICIPANTS

'Low-risk' women with a 'term' pregnancy planning vaginal birth in a stratified, random sample of 36 OUs.

MAIN OUTCOME MEASURES

Adjusted rates of intrapartum caesarean section, instrumental delivery and two composite measures capturing birth without intervention ('straightforward' and 'normal' birth).

RESULTS

Funnel plots showed unexplained variation in adjusted intervention rates. In NHS trusts where proportionately more non-OU births were planned, adjusted intrapartum caesarean section rates in the planned OU births were significantly higher (nulliparous: R(2)=31.8%, coefficient=0.31, p=0.02; multiparous: R(2)=43.2%, coefficient=0.23, p=0.01), and for multiparous women, rates of 'straightforward' (R(2)=26.3%, coefficient=-0.22, p=0.01) and 'normal' birth (R(2)=17.5%, coefficient=0.24, p=0.01) were lower. The size of the OU (number of births), midwifery 'under' staffing levels (the proportion of shifts where there were more women than midwives) and the presence of an AMU were associated with significant variation in some interventions.

CONCLUSIONS

Trusts with greater provision of non-OU intrapartum care may have higher intervention rates in planned 'low-risk' OU births, but at a trust level this is likely to be more than offset by lower intervention rates in planned non-OU births. Further research using high quality data on unit characteristics and outcomes in a larger sample of OUs and trusts is required.

Etiology of severe childhood pneumonia in the Gambia, West Africa, determined by conventional and molecular microbiological analyses of lung and pleural aspirate samples

Molecular analyses of lung aspirates from Gambian children with severe pneumonia detected pathogens more frequently than did culture and showed a predominance of bacteria, principally Streptococcuspneumoniae, >75% being of serotypes covered by current pneumococcal conjugate vaccines. Multiple pathogens were detected frequently, notably Haemophilus influenzae (mostly nontypeable) together with S. pneumoniae.

Immersion in water for pain relief and the risk of intrapartum transfer among low risk nulliparous women: secondary analysis of the Birthplace national prospective cohort study

BACKGROUND

Immersion in water during labour is an important non-pharmacological method to manage labour pain, particularly in midwifery-led care settings where pharmacological methods are limited. This study investigates the association between immersion for pain relief and transfer before birth and other maternal outcomes.

METHODS

A prospective cohort study of 16,577 low risk nulliparous women planning birth at home, in a freestanding midwifery unit (FMU) or in an alongside midwifery unit (AMU) in England between April 2008 and April 2010.

RESULTS

Immersion in water for pain relief was common; 50% in planned home births, 54% in FMUs and 38% in AMUs. Immersion in water was associated with a lower risk of transfer before birth for births planned at home (adjusted RR 0.88; 95% CI 0.79-0.99), in FMUs (adjusted RR 0.59; 95% CI 0.50-0.70) and in AMUs (adjusted RR 0.78; 95% CI 0.69-0.88). For births planned in FMUs, immersion in water was associated with a lower risk of intrapartum caesarean section (RR 0.61; 95% CI 0.44-0.84) and a higher chance of a straightforward vaginal birth (RR 1.09; 95% CI 1.04-1.15). These beneficial effects were not seen in births planned at home or AMUs.

CONCLUSIONS

Immersion of water for pain relief was associated with a significant reduction in risk of transfer before birth for nulliparous women. Overall, immersion in water was associated with fewer interventions during labour. The effect varied across birth settings with least effect in planned home births and a larger effect observed for planned FMU births.

The effect of maternal age and planned place of birth on intrapartum outcomes in healthy women with straightforward pregnancies: secondary analysis of the Birthplace national prospective cohort study

OBJECTIVES

To describe the relationship between maternal age and intrapartum outcomes in 'low-risk' women; and to evaluate whether the relationship between maternal age and intrapartum interventions and adverse outcomes differs by planned place of birth.

DESIGN

Prospective cohort study.

SETTING

Obstetric units (OUs), midwifery units and planned home births in England.

PARTICIPANTS

63 371 women aged over 16 without known medical or obstetric risk factors, with singleton pregnancies, planning vaginal birth.

METHODS

Log Poisson regression was used to evaluate the association between maternal age, modelled as a continuous and categorical variable, and risk of intrapartum interventions and adverse maternal and perinatal outcomes.

MAIN OUTCOME MEASURES

Intrapartum caesarean section, instrumental delivery, syntocinon augmentation and a composite measure of maternal interventions/adverse outcomes requiring obstetric care encompassing augmentation, instrumental delivery, intrapartum caesarean section, general anaesthesia, blood transfusion, third-degree/fourth-degree tear, maternal admission; adverse perinatal outcome (encompassing neonatal unit admission or perinatal death).

RESULTS

Interventions and adverse maternal outcomes requiring obstetric care generally increased with age, particularly in nulliparous women. For nulliparous women aged 16-40, the risk of experiencing an intervention or adverse outcome requiring obstetric care increased more steeply with age in planned non-OU births than in planned OU births (adjusted RR 1.21 per 5-year increase in age, 95% CI 1.18 to 1.25 vs adjusted RR 1.12, 95% CI 1.10 to 1.15) but absolute risks were lower in planned non-OU births at all ages. The risk of neonatal unit admission or perinatal death was significantly raised in nulliparous women aged 40+ relative to women aged 25-29 (adjusted RR 2.29, 95% CI 1.28 to 4.09).

CONCLUSIONS

At all ages, 'low-risk' women who plan birth in a non-OU setting tend to experience lower intervention rates than comparable women who plan birth in an OU. Younger nulliparous women appear to benefit more from this reduction than older nulliparous women.

The neighbourhood method for measuring differences in maternal mortality, infant mortality and other rare demographic events

In the absence of reliable systems for registering rare types of vital events large surveys are required to measure changes in their rates. However some events such as maternal deaths are widely known about in the community. This study examined the utility of asking respondents about events in their neighbourhood as an efficient method for measuring relative rates of rare health events such as maternal and infant deaths. A survey was conducted in the health and demographic surveillance system (HDSS) in Matlab, Bangladesh, which includes two areas with different health care regimes. Adult women were asked about any maternal deaths; multiple births; infant deaths, live births and some other events they knew of in a small specified area around their home. Agreement between HDSS records and survey responses was moderate or better (kappa≥0.44) for all the events and greatest for maternal deaths (kappa = 0.77) with 84% being reported. Most events were more likely to be reported if they were recent (p<0.05). Infant mortality rate in one area was 0.56 times that in the other which was well reflected by the ratio of survey results (0.53). Simulations were used to study the ability of the method to detect differences in maternal mortality ratio. These suggested that a sample size around 5000 would give 80% power to detect a 50% decrease from a baseline of 183 which compared well with an estimated sample size around 10 times larger using the direct sisterhood method. The findings suggest that the Neighbourhood Method has potential for monitoring relative differences between areas or changes over time in the rates of rare demographic events, requiring considerably smaller sample sizes than traditional methods. This raises the possibility for interventions to demonstrate real effects on outcomes such as maternal deaths where previously this was only feasible by indirect methods.

Duration and urgency of transfer in births planned at home and in freestanding midwifery units in England: secondary analysis of the birthplace national prospective cohort study

BACKGROUND

In England, there is a policy of offering healthy women with straightforward pregnancies a choice of birth setting. Options may include home or a freestanding midwifery unit (FMU). Transfer rates from these settings are around 20%, and higher for nulliparous women. The duration of transfer is of interest because of the potential for delay in access to specialist care and is also of concern to women. We aimed to estimate the duration of transfer in births planned at home and in FMUs and explore the effects of distance and urgency on duration.

METHODS

This was a secondary analysis of data collected in a national prospective cohort study including 27,842 'low risk' women with singleton, term, 'booked' pregnancies, planning birth in FMUs or at home in England from April 2008 to April 2010. We described transfer duration using the median and interquartile range, for all transfers and those for reasons defined as potentially urgent or non-urgent, and used cumulative distribution curves to compare transfer duration by urgency. We explored the effect of distance for transfers from FMUs and described outcomes in women giving birth within 60 minutes of transfer.

RESULTS

The median overall transfer time, from decision to transfer to first OU assessment, was shorter in transfers from home compared with transfers from FMUs (49 vs 60 minutes; p < 0.001). The median duration of transfers before birth for potentially urgent reasons (home 42 minutes, FMU 50 minutes) was 8-10 minutes shorter compared with transfers for non-urgent reasons. In transfers for potentially urgent reasons, the median overall transfer time from FMUs within 20 km of an OU was 47 minutes, increasing to 55 minutes from FMUs 20-40 km away and 61 minutes in more remote FMUs. In women who gave birth within 60 minutes after transfer, adverse neonatal outcomes occurred in 1-2% of transfers.

CONCLUSIONS

Transfers from home or FMU commonly take up to 60 minutes from decision to transfer, to first assessment in an OU, even for transfers for potentially urgent reasons. Most transfers are not urgent and emergencies and adverse outcomes are uncommon, but urgent transfer is more likely for nulliparous women.

Nasopharyngeal carriage of pneumococci four years after community-wide vaccination with PCV-7 in The Gambia: long-term evaluation of a cluster randomized trial

Background

A village-randomized trial of a seven-valent pneumococcal-conjugate-vaccine (PCV-7) conducted in rural Gambia showed a decrease of vaccine-type (VT) and a non-significant increase in non-vaccine-type (NVT) nasopharyngeal carriage of pneumococci two years after vaccination. Here, we report findings four years after vaccination.

Methods

PCV-7 was given to all children below 30 months of age enrolled in the trial and to those born during its course in all study villages. Villages were randomized (older children and adults) to receive PCV-7 (wholly vaccinated villages) or serogroup-C-meningococcal-conjugate-vaccine (partly vaccinated villages). Cross-sectional surveys (CSS) to collect nasopharyngeal swabs were conducted before and at various intervals after vaccination. Sixteen of these randomized villages (8 wholly vaccinated and 8 partly vaccinated) participated in a CSS conducted four years after vaccination started.

Results

Four years after vaccination, the prevalence of VT pneumococcal carriage was slightly higher in partly than in wholly vaccinated villages [6.4% versus 3.9% (p = 0.120)] compared to 24.4% in the pre-vaccination CSS (p<0.001). Prevalence of NVT four years after vaccination was similar between study groups [32.7% versus 29.8% (p = 0.392), respectively] compared to 51.1% in the pre-vaccination CSS (p<0.001). Four years after vaccination started, lower prevalence of serotype 6A was detected in wholly vaccinated than in partly vaccinated villages (1.6% versus 3.5%, p = 0.093) whilst the prevalence of serotype 19A was similar between groups (2.9% versus 2.5%, p = 0.779). The most prevalent serotype 19A clone was ST 847. The most prevalent serotype 6A clone before vaccination was ST3324 whilst after vaccination ST913 and ST1737 predominated. Fourteen out of 26 STs detected among the serotype 6A isolates were new while no new 19A serotype ST was found.

Conclusions

The decline in prevalence of VT pneumococci seen shortly after PCV-7 vaccination was sustained four years later with only a small difference between study arms. No significant serotype replacement was detected.

Trial Registration

ClinicalTrials.gov ISRCTN51695599

Achieving comprehensive childhood immunization: an analysis of obstacles and opportunities in The Gambia

Introduction Immunization is a vital component in the drive to decrease global childhood mortality, yet challenges remain in ensuring wide coverage of immunization and full immunization, particularly in low- and middle-income countries. This study assessed immunization coverage and the determinants of immunization in a semi-rural area in The Gambia.

Methods Data were drawn from the Farafenni Health and Demographic Surveillance System. Children born within the surveillance area between January 2000 and December 2010 were included. Main outcomes assessed included measles, BCG and DTP vaccination status and full immunization by 12 months of age as reported on child healthcards. Predictor variables were evaluated based on a literature review and included gender, ethnicity, area of residence, household wealth and mother’s age.

Results Of the 7363 children included in the study, immunization coverage was 73% (CI 72–74) for measles, 86% (CI 86–87) for BCG, 79% (CI 78–80) for three doses of DTP and 52% (CI 51–53) for full immunization. Coverage was significantly associated with area of residence and ethnicity, with children in urban areas and of Mandinka ethnicity being least likely to be fully immunized.

Conclusions Despite high levels of coverage of many individual vaccines, delivery of vaccinations later in the schedule and achieving high coverage of full immunization remain challenges, even in a country with a committed childhood immunization programme, such as The Gambia. Our data indicate areas for targeted interventions by the national Expanded Programme of Immunization.

Indirect effect of 7-valent pneumococcal conjugate vaccine on pneumococcal carriage in newborns in rural Gambia: a randomised controlled trial

Background

Gambian infants frequently acquire Streptococcus pneumoniae soon after birth. We investigated the indirect effect of 7-valent pneumococcal conjugate vaccine (PCV-7) on pneumococcal acquisition in newborn Gambian babies.

Methods

Twenty-one villages were randomised to receive PCV-7 to all subjects (11 vaccinated villages) or to infants aged 2–30 months (10 control villages). Other control villagers received Meningococcal C conjugate vaccine. From 328 babies born during the trial, nasopharyngeal swabs were collected after birth, then weekly until 8 weeks of age when they received their first dose of PCV-7. Pneumococcal carriage and acquisition rates were compared between the study arms and with a baseline study.

Results

57.4% of 2245 swabs were positive for S. pneumoniae. Overall carriage was similar in both arms. In vaccinated villages fewer infants carried pneumococci of vaccine serotypes (VT) (16.9% [31/184] vs. 37.5% [54/144], p<0.001) and more carried pneumococci of non-vaccine serotypes (NVT) (80.9% [149/184] vs. 75.7% [109/144], p = 0.246). Infants from vaccinated villages had a significantly lower acquisition rate of VT (HR 0.39 [0.26–0.58], p<0.001) and increased acquisition of NVT (HR 1.16 [0.87–1.56], p = 0.312). VT carriage (51.6% vs. 37.5%, p = 031 in control and 46.1% vs. 16.8%, p<0.001 in vaccinated villages) and acquisition rates (HR 0.68 [0.50–0.92], p = 0.013 in control villages and HR 0.31 [0.19–0.50], p<.001 in vaccinated villages) were significantly lower in both study arms than in the baseline study. NVT carriage (63.2% vs. 75.7%, p = 0.037 in control and 67.2% vs. 75.3%, p = 0.005 in vaccinated villages) and acquisition rates (HR 1.48 [1.06–2.06], p = 0.022) and (HR 1.52 [1.11–2.10], p = 0.010 respectively) were significantly higher.

Conclusion

PCV-7 significantly reduced carriage of VT pneumococci in unvaccinated infants. This indirect effect likely originated from both the child and adult vaccinated populations. Increased carriage of NVT pneumococci needs ongoing monitoring.

Trial Registration

ISRCTN Register 51695599

Are plasma biomarkers of immune activation predictive of HIV progression: a longitudinal comparison and analyses in HIV-1 and HIV-2 infections?

Background

Chronic immune activation is a hallmark of HIV infection and has been associated with disease progression. Assessment of soluble biomarkers indicating immune activation provide clues into pathogenesis and hold promise for the development of point-of-care monitoring of HIV in resource-poor-settings. Their evaluation in cohort resources is therefore needed to further their development and use in HIV research.

Methodology/Principal Findings

Longitudinal evaluation of βeta-2 microglobulin (β-2 m), neopterin and suPAR soluble urokinase-type plasminogen activator receptor (suPAR) was performed with archived plasma samples to predict disease progression and provided the first direct comparison of levels in HIV-1 and HIV-2 infections. At least 2095 samples from 137 HIV-1 and 198 HIV-2 subjects with starting CD4% of ≥28 and median follow up of 4 years were analysed. All biomarkers were correlated negatively to CD4% and positively to viral load and to each other. Analyses in subjects living for ≥5 years revealed increases in median β-2 m and neopterin and decreases in CD4% over this period and the odds of death within 5 years were positively associated with baseline levels of β-2 m and neopterin. ROC analyses strengthened the evidence of elevation of biomarkers in patients approaching death in both HIV-1 and HIV-2 infections. Regression models showed that rates of biomarker fold change accelerated from 6–8 years before death with no significant differences between biomarker levels in HIV-1 and HIV-2 at equal time points prior to death.An ‘immune activation index’ analysis indicative of biomarker levels at equivalent viral loads also showed no differences between the two infections.

Conclusions/Significance

Our results suggest that β-2 m and neopterin are useful tools for disease monitoring in both HIV-1 and HIV-2 infections, whereas sUPAR performed less well. Levels of immune activation per amount of virus were comparable in HIV-1 and HIV-2 infected subjects.

Treatment outcomes among HIV-1 and HIV-2 infected children initiating antiretroviral therapy in a concentrated low prevalence setting in West Africa

Background

There is little data on responses to combination antiretroviral therapy (cART) among HIV-infected children in the West African region. We describe treatment outcomes among HIV-1 and HIV-2 infected children initiating cART in a research clinic in The Gambia, West Africa.

Methods

All treatment naive HIV-infected children who initiated cART according to the WHO ART guidelines for children between October 2004 and December 2009 were included in the analysis. Kaplan-Meir estimates and sign-rank test were used to investigate the responses to treatment.

Results

65 HIV-1 and five HIV-2 infected children aged < 15 years were initiated on cART over this time period. HIV-1 infected children were treated with a combination of Zidovudine or Stavudine + Lamivudine + Nevirapine or Efavirenz while children with HIV-2 were treated with Zidovudine + Lamivudine + ritonavir-boosted Lopinavir. HIV-1 infected children were followed-up for a median (IQR) duration of 20.1 months (6.9 – 34.3), with their median (IQR) age at treatment initiation, CD4% and plasma viral load at baseline found to be 4.9 years (2.1 – 9.1), 13.0% (7.0 – 16.0) and 5.4 log₁₀ copies/ml (4.4 – 6.0) respectively. The median age at treatment initiation of the five HIV-2 infected children was 12 years (range: 4.6 – 14.0) while their median baseline CD4⁺ T cell count and HIV-2 viral load were 140 cells/mm³ (Range: 40 – 570 cells/mm³) and 4.5 log₁₀copies/mL (Range: 3.1 - 4.9 log₁₀copies/mL) respectively.

Among HIV-1 infected children <5 years of age at ART initiation, the median (IQR) increases in CD4% from baseline to 12, 24 and 36 months were 14% (8 – 19; P = 0.0004), 21% (15 – 22; P = 0.005) and 15% (15 – 25; P = 0.0422) respectively, while the median (IQR) increase in absolute CD4 T cell count from baseline to 12, 24 and 36 months for those ≥5 years at ART initiation were 470 cells/mm³ (270 – 650; P = 0.0005), 230 cells/mm³ (30 – 610; P = 0.0196) and 615 cells/mm³ (250 – 1060; P = 0.0180) respectively. The proportions of children achieving undetectable HIV-1 viral load at 6-, 12-, 24- and 36 months of treatment were 24/38 (63.2%), 20/36 (55.6%), 8/22 (36.4%) and 7/12 (58.3%) respectively. The probability of survival among HIV-1 infected children after 12 months on ART was 89.9% (95% CI 78.8 – 95.3). CD4 T cell recovery was sub-optimal in all the HIV-2 infected children and none achieved virologic suppression. Two of the HIV-2 infected children died within 6 months of starting treatment while the remaining three were lost to follow-up.

Conclusions

The beneficial effects of cART among HIV-1 infected children in our setting are sustained in the first 24 months of treatment with a significant improvement in survival experience up to 36 months; however the outcome was poor in the few HIV-2 infected children initiated on cART.

Assessment of von Willebrand disease as a risk factor for primary postpartum haemorrhage

It is not clear whether von Willebrand disease (VWD) is associated with an increased risk of postpartum haemorrhage (PPH). We assessed the effect of VWD on PPH in a case-control study. Logistic regression was used to test for differences in the odds of PPH in deliveries to women with and without VWD, before and after adjustment for known risk factors. A total of 62 deliveries in 33 women with VWD were compared with controls matched for age, year of delivery and parity. Primary PPH was observed in 12/62 (19.4%) deliveries in women with VWD and 16/124 (12.9%) controls. The unadjusted odds ratio (OR) for VWD as a risk factor for PPH was 1.62 (95% CI 0.75-3.49, P = 0.22). After adjustment for other risk factors for PPH, the OR for VWD as a risk factor for PPH was 1.31 (95% CI 0.48-3.60, P = 0.60). PPH was observed in 7/24 (29%) deliveries in women known prepregnancy to have VWD. The unadjusted odds for VWD as a risk factor for PPH in this group was significantly greater than the control group (OR 2.78 (95% CI 1.03-7.49) P = 0.043) and remained significant after adjusting for other significant risk factors (OR 3.41 (95% CI 1.07-10.9) P = 0.038). VWD in itself may not be a significant risk factor for PPH, however, women known to have VWD predelivery may represent an at risk sub-group.

Interventions for prevention of giant retinal tear in the fellow eye

BACKGROUND

A giant retinal tear is a full-thickness retinal break that extends circumferentially around the retina for 90 degrees or more in the presence of a posteriorly detached vitreous. It causes significant visual morbidity from retinal detachment and proliferative vitreoretinopathy. The fellow eye of patients who have had a spontaneous giant retinal tear has an increased risk of developing a giant retinal tear, a retinal detachment or both. Interventions such as 360-degree encircling scleral buckling, 360-degree cryotherapy and 360-degree laser photocoagulation have been advocated by some ophthalmologists as prophylaxis for the fellow eye against the development of a giant retinal tear and/or a retinal detachment, or to prevent its extension.

OBJECTIVES

To evaluate the effectiveness of prophylactic 360-degree interventions in the fellow eye of patients with unilateral giant retinal tear to prevent the occurrence of a giant retinal tear, a retinal detachment or both.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 11), MEDLINE (January 1950 to December 2011), EMBASE (January 1980 to December 2011), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to December 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 6 December 2011. In addition, we searched the proceedings of the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) up to 2008 for information about other relevant studies.

SELECTION CRITERIA

Prospective randomised controlled trials (RCTs) comparing one prophylactic treatment for fellow eyes of patients with giant retinal tear against observation (no treatment) or another form of prophylactic treatment. In the absence of RCTs, we planned to discuss case-control studies that met the inclusion criteria but we would not conduct a meta-analysis using these studies.

DATA COLLECTION AND ANALYSIS

We did not find any studies that met the inclusion criteria for the review and therefore no assessment of methodological quality or meta-analysis could be performed.

MAIN RESULTS

No studies met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

No strong evidence in the literature was found to support or refute prophylactic 360-degree treatments to prevent a giant retinal tear or a retinal detachment in the fellow eye of patients with unilateral giant retinal tears.

Highly accurate diagnosis of pleural tuberculosis by immunological analysis of the pleural effusion

Pleural TB is notoriously difficult to diagnose due to its paucibacillary nature yet it is the most common cause of pleural effusions in TB endemic countries such as The Gambia. We identified both cellular and soluble biomarkers in the pleural fluid that allowed highly accurate diagnosis of pleural TB compared to peripheral blood markers. Multi-plex cytokine analysis on unstimulated pleural fluid showed that IP-10 resulted in a positive likelihood ratio (LR) of 9.6 versus 2.8 for IFN-γ; a combination of IP-10, IL-6 and IL-10 resulted in an AUC of 0.96 and positive LR of 10. A striking finding was the significantly higher proportion of PPD-specific IFN-γ+TNF-α+ cell population (PPD-IGTA) in the pleural fluid compared to peripheral blood of TB subjects. Presence of this pleural PPD-IGTA population resulted in 95% correct classification of pleural TB disease with a sensitivity of 95% and specificity of 100%. These data suggest that analysis of the site of infection provides superior diagnostic accuracy compared to peripheral blood for pleural TB, likely due to the sequestration of effector cells at this acute stage of disease.

Effects of community-wide vaccination with PCV-7 on pneumococcal nasopharyngeal carriage in the Gambia: a cluster-randomized trial

BACKGROUND

Introduction of pneumococcal conjugate vaccines (PCVs) of limited valency is justified in Africa by the high burden of pneumococcal disease. Long-term beneficial effects of PCVs may be countered by serotype replacement. We aimed to determine the impact of PCV-7 vaccination on pneumococcal carriage in rural Gambia.

METHODS AND FINDINGS

A cluster-randomized (by village) trial of the impact of PCV-7 on pneumococcal nasopharyngeal carriage was conducted in 21 Gambian villages between December 2003 to June 2008 (5,441 inhabitants in 2006). Analysis was complemented with data obtained before vaccination. Because efficacy of PCV-9 in young Gambian children had been shown, it was considered unethical not to give PCV-7 to young children in all of the study villages. PCV-7 was given to children below 30 mo of age and to those born during the trial in all study villages. Villages were randomized (older children and adults) to receive one dose of PCV-7 (11 vaccinated villages) or meningococcal serogroup C conjugate vaccine (10 control villages). Cross-sectional surveys (CSSs) to collect nasopharyngeal swabs were conducted before vaccination (2,094 samples in the baseline CSS), and 4-6, 12, and 22 mo after vaccination (1,168, 1,210, and 446 samples in CSS-1, -2, and -3, respectively). A time trend analysis showed a marked fall in the prevalence of vaccine-type pneumococcal carriage in all age groups following vaccination (from 23.7% and 26.8% in the baseline CSS to 7.1% and 8.5% in CSS-1, in vaccinated and control villages, respectively). The prevalence of vaccine-type pneumococcal carriage was lower in vaccinated than in control villages among older children (5 y to <15 y of age) and adults (≥15 y of age) at CSS-2 (odds ratio [OR] = 0.15 [95% CI 0.04-0.57] and OR = 0.32 [95% CI 0.10-0.98], respectively) and at CSS-3 (OR = 0.37 [95% CI 0.15-0.90] for older children, and 0% versus 7.6% for adults in vaccinated and control villages, respectively). Differences in the prevalence of non-vaccine-type pneumococcal carriage between vaccinated and control villages were small.

CONCLUSIONS

Vaccination of Gambian children reduced vaccine-type pneumococcal carriage across all age groups, indicating a "herd effect" in non-vaccinated older children and adults. No significant serotype replacement was detected. Please see later in the article for the Editors' Summary.

Comparison of electronic data capture (EDC) with the standard data capture method for clinical trial data

Background

Traditionally, clinical research studies rely on collecting data with case report forms, which are subsequently entered into a database to create electronic records. Although well established, this method is time-consuming and error-prone. This study compares four electronic data capture (EDC) methods with the conventional approach with respect to duration of data capture and accuracy. It was performed in a West African setting, where clinical trials involve data collection from urban, rural and often remote locations.

Methodology/Principal Findings

Three types of commonly available EDC tools were assessed in face-to-face interviews; netbook, PDA, and tablet PC. EDC performance during telephone interviews via mobile phone was evaluated as a fourth method. The Graeco Latin square study design allowed comparison of all four methods to standard paper-based recording followed by data double entry while controlling simultaneously for possible confounding factors such as interview order, interviewer and interviewee. Over a study period of three weeks the error rates decreased considerably for all EDC methods. In the last week of the study the data accuracy for the netbook (5.1%, CI95%: 3.5–7.2%) and the tablet PC (5.2%, CI95%: 3.7–7.4%) was not significantly different from the accuracy of the conventional paper-based method (3.6%, CI95%: 2.2–5.5%), but error rates for the PDA (7.9%, CI95%: 6.0–10.5%) and telephone (6.3%, CI95% 4.6–8.6%) remained significantly higher. While EDC-interviews take slightly longer, data become readily available after download, making EDC more time effective. Free text and date fields were associated with higher error rates than numerical, single select and skip fields.

Conclusions

EDC solutions have the potential to produce similar data accuracy compared to paper-based methods. Given the considerable reduction in the time from data collection to database lock, EDC holds the promise to reduce research-associated costs. However, the successful implementation of EDC requires adjustment of work processes and reallocation of resources.

Reaching millennium development goal 4 - the Gambia

To describe how, through a DSS in a rural area of The Gambia, it has been possible to measure substantial reductions in child mortality rates and how we investigated whether the decline paralleled the registered fall in malaria incidence in the country.

METHODS

Demographic surveillance data spanning 19.5 years (1 April 1989-30 September 2008) from 42 villages around the town of Farafenni, The Gambia, were used to estimate childhood mortality rates for neonatal, infant, child (1-4 years) and under-5 age groups. Data were presented in five a priori defined time periods, and annual rates per 1000 live births were derived from Kaplan-Meier survival probabilities.

RESULTS

From 1989-1992 to 2004-2008, under-5 mortality declined by 56% (95% CI: 48-63%), from 165 (95% CI: 151-181) per 1000 live births to 74 (95% CI: 65-84) per 1000 live births. In 1- to 4-year-olds, mortality during the period 2004-2008 was 69% (95% CI: 60-76%) less than in 1989-1992. The corresponding mortality decline in infants was 39% (95% CI: 23-52%); in neonates, it was 38% (95% CI: 13-66%). The derived annual under-5 mortality rates declined from 159 per 1000 live births in 1990 to 45 per 1000 live births in 2008, thus implying an attainment of MDG4 seven years in advance of the target year of 2015.

CONCLUSION

Achieving MDG4 is possible in poor, rural areas of Africa through widespread deployment of relatively simple measures that improve child survival, such as immunisation and effective malaria control.