Developing retinal biomarkers of neurological disease: an analytical perspective

The inaccessibility of the brain poses a problem for neuroscience. Scientists have traditionally responded by developing biomarkers for brain physiology and disease. The retina is an attractive source of biomarkers since it shares many features with the brain. Some even describe the retina as a ‘window’ to the brain, implying that retinal signs are analogous to brain disease features. However, new analytical methods are needed to show whether or not retinal signs really are equivalent to brain abnormalities, since this requires greater evidence than direct associations between retina and brain. We, therefore propose a new way to think about, and test, how clearly one might see the brain through the retinal window, using cerebral malaria as a case study

The impact of rapid malaria diagnostic tests upon anti-malarial sales in community pharmacies in Gwagwalada, Nigeria

Background Rapid diagnostics tests for malaria (RDT) have become established as a practical solution to the challenges of parasitological confirmation of malaria before treatment in the public sector. However, little is known of their impact in private health sector facilities, such as pharmacies and drug shops. This study aimed to assess the incidence of malaria among unwell patients seeking anti-malarial treatment in two community pharmacies in Nigeria and measure the impact RDTs have on anti-malarial sales. Methods This was a comparison study of two pharmacies located in the suburbs of Gwagwalada, in the Federal Capital Territory of Nigeria, between May and July 2012. In the intervention arm, patients seeking to purchase anti-malarials had an RDT performed before treatment while the control pharmacy continued normal routine practice. Results A total of 1,226 participants were enrolled into the study. The incidence of malaria in the intervention arm (n = 619) was 13.6% and adolescent participants had a statistically significant higher incidence (26.0%) compared to adults (11.9%) (P = 0.001). A history of fever in the last 48 hours was associated with a statistically significant higher incidence of malaria (28.3%) (P < 0.001). Having a RDT test reduced the chance of purchasing an anti-malarial by 42% (95% CI: 38%-46%) compared to not having a test. 51.6% (276) of the study participants with a RDT negative result still purchased anti-malarials, especially if anti-malarials had been recommended by a health professional (58.9%) compared to self-referral (44.2%) (P = 0.001). Patients with RDT negative results were also more likely to purchase an anti-malarial if there was a reported malaria positive laboratory test prior to presentation (66.2%; P = 0.007), a history of fever in the last 48 hours (60.5%; P = 0.027), and primary school education or less (69.4%; P = 0.009). After adjusting for age group and gender differences, having at least a secondary school education reduced the chance of buying an anti-malarial (OR 0.504 (95% CI: 0.256-0.993)) compared to having primary education or lower. Conclusion The study highlights the enormous potential for improving appropriate prescription of anti-malarials in pharmacies and preventing unnecessary use of artemisinin combination therapy (ACT)

Automated counting for Plasmodium falciparum cytoadherence experiments.

The automated counting programs are an accurate and practical way of quantifying static parasite binding assays to purified proteins. They are less accurate when applied to cell based systems, but can still provide a reasonable level of accuracy to give a semi-quantitative readout

Study protocol: the effects of air pollution exposure and chronic respiratory disease on pneumonia risk in urban Malawian adults - the Acute Infection of the Respiratory Tract Study (The AIR Study)

Background Pneumonia is the 2nd leading cause of years of life lost worldwide and is a common cause of adult admissions to hospital in sub-Saharan Africa. Risk factors for adult pneumonia are well characterised in developed countries, but are less well described in sub-Saharan Africa where HIV is a major contributing factor. Exposure to indoor and outdoor air pollution is high, and tobacco smoking prevalence is increasing in sub-Saharan Africa, yet the contribution of these factors to the burden of chronic respiratory diseases in sub-Saharan Africa remains poorly understood. Furthermore, the extent to which the presence of chronic respiratory diseases and exposure to air pollution contribute to the burden of pneumonia is not known. Design The Acute Infection of the Respiratory Tract Study (The AIR Study) is a case–control study to identify preventable risk factors for adult pneumonia in the city of Blantyre, Malawi. Cases will be adults admitted with pneumonia, recruited from Queen Elizabeth Central Hospital, the largest teaching hospital in Malawi. Controls will be adults without pneumonia, recruited from the community. The AIR Study will recruit subjects and analyse data within strata defined by positive and negative HIV infection status. All participants will undergo thorough assessment for a range of potential preventable risk factors, with an emphasis on exposure to air pollution and the presence of chronic respiratory diseases. This will include collection of questionnaire data, clinical samples (blood, urine, sputum and breath samples), lung function data and air pollution monitoring in their home. Multivariate analysis will be used to identify the important risk factors contributing to the pneumonia burden in this setting. Identification of preventable risk factors will justify research into the effectiveness of targeted interventions to address this burden in the future. Discussion The AIR Study is the first study of radiologically confirmed pneumonia in which air pollution exposure measurements have been undertaken in this setting, and will contribute important new information about exposure to air pollution in urban SSA. Through identification of preventable risk factors, the AIR Study aims to facilitate future research and implementation of targeted interventions to reduce the high burden of pneumonia in SSA

The use of insecticide-treated nets for reducing malaria morbidity among children aged 6-59 months, in an area of high malaria transmission in central Cote d'Ivoire

Background Long-lasting insecticidal nets (LLINs) are an important tool for controlling malaria. Much attention has been devoted to determine both the effect of LLINs on the reduction of Plasmodium infection rate and clinically-confirmed malaria cases in sub-Saharan Africa. We carried out epidemiological analyses to investigate whether LLINs impact on Plasmodium prevalence rate and the proportion of clinically-confirmed malaria cases, in five villages in the district of Toumodi, central Cote d'Ivoire. Methods From April 2007 to November 2008, a community-based malaria control programme was implemented in the study villages, which involved large-scale distribution of LLINs, and training and sensitization activities within the community. We determined the effect of this programme on Plasmodium prevalence rate, clinically-confirmed malaria cases and parasitaemia rates in children aged 6-59 months through a series of cross-sectional surveys starting in April 2007 and repeated once every 6 months. Results We observed a significant decrease in the mean P. falciparum prevalence rate from April 2007 to April 2008 (p = 0.029). An opposite trend was observed from November 2007 to November 2008 when P. falciparum prevalence rate increased significantly (p = 0.003). Highly significant decreases in the proportions of clinical malaria cases were observed between April 2007 and April 2008 (p < 0.001), and between November 2007 and November 2008 (p = 0.001). Conclusions Large-scale distribution of LLINs, accompanied by training and sensitization activities, significantly reduced Plasmodium prevalence rates among young children in the first year of the project, whereas overall clinical malaria rates dropped over the entire 18-month project period. A decrease in community motivation to sleep under bed nets, perhaps along with changing patterns of malaria transmission, might explain the observed increase in the Plasmodium prevalence rate between November 2007 and November 2008

Adjusted Risk Difference Estimation: An Assessment of Convergence Problems with Application to Malaria Efficacy Studies

A common measure of treatment effect in malaria efficacy studies is the risk difference, which can be estimated using binomial regression models. These models can fail to provide estimates, however, due to model failure or model convergence problems. Such failure most commonly occurs when the rate is close to 0% or 100% (a “boundary problem”) but can also occur occasionally even when the rate is not close to a boundary. This paper reports the findings from simulation studies performed to evaluate the factors that may contribute to model failure when using binomial regression to derive risk difference estimates. Convergence rates were found to fall: i) As one or both efficacy rates moved towards a boundary value, irrespective of the number of covariates included in the model; ii) As the numbers of covariates in the model increased; iii) As the levels of correlation between covariates the covariates increased. In all circumstances, convergence was poor when the efficacy rate in either group was 90% or more

Prevalence of Potential Drug-Drug Interactions Involving Antiretroviral Drugs in a Large Kenyan Cohort

Background: Clinically significant drug-drug interactions (CSDIs) involving antiretrovirals are frequent and under-recognizedin developed countries, but data are lacking for developing countries. Methodology and Principal Findings: To investigate the prevalence of CSDIs between antiretrovirals and coadministered drugs, we surveyed prescriptions dispensed in a large HIV clinic in Kenya. Of 1040 consecutive patients screened, 996 were eligible for inclusion. CSDIs were defined as ‘major’ (capable of causing severe or permanent damage, contraindicated, avoid or not recommended by the manufacturer, or requiring dose modification) ‘moderate’ (manufacturers advise caution, or close monitoring, or capable of causing clinical deterioration). A total of 334 patients (33.5%) were at risk for a CSDI, potentially lowering antiretroviral drug concentrations in 120 (12%) patients. Major interactions most frequently involved rifampicin (12.4%, mostly with efavirenz) and azoles (2.7%) whereas moderate interactions were frequently azoles (13%), steroids (11%), and antimalarials (3%). Multivariable analyses suggested that patients at risk for CSDIs had lower CD4 counts (P = 0.006) and baseline weight (P = 0.023) and WHO Stage 3 or 4 disease (P#0.007). Risk for CSDIs was not associated with particular regimens, although only 116 (11.6%) patients were receiving WHO second line regimens. Conclusions: One in three patients receiving antiretrovirals in our programme were at risk of CSDIs. Strategies need to be urgently developed to avoid important drug interactions, to identify early markers of toxicity and to manage unavoidable interactions safely in order to reduce risk of harm, and to maximize the effectiveness of mass antiretroviral deployment in Africa

Foley catheterisation versus oral misoprostol for induction of labour in hypertensive women in India (INFORM): a multicentre, open-label, randomised controlled trial

Background Between 62 000 and 77 000 women die annually from pre-eclampsia and eclampsia. Prompt delivery, preferably by the vaginal route, is vital for good maternal and neonatal outcomes. Two low-cost interventions—low-dose oral misoprostol tablets and transcervical Foley catheterisation—are already used in low-resource settings. We aimed to compare the relative risks and benefits of these interventions. Methods We undertook this multicentre, open-label, randomised controlled trial in two public hospitals in Nagpur, India. Women (aged ≥18 years) who were at 20 weeks' gestation or later with a live fetus and required delivery as a result of pre-eclampsia or hypertension were randomly assigned (1:1), via computer-generated block randomisation (block sizes of four, six, and eight) with concealment by use of opaque, sequentially numbered, sealed envelopes, to receive labour induction with either oral misoprostol 25 μg every 2 h (maximum of 12 doses) or a transcervical Foley catheter (silicone, size 18 F with 30 mL balloon). Randomisation was stratified by study centre. The catheter remained in place until active labour started, the catheter fell out, or 12 h had elapsed. If the catheter did not fall out within 12 h, induction continued with artificial membrane rupture and oxytocin, administered through a micro-drip gravity infusion set. Fetal monitoring was by intermittent auscultation. The primary outcome was vaginal birth within 24 h. Due to the nature of the interventions, masking of participants, study investigators, and care providers to group allocation was not possible. We analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01801410. Findings Between Dec 20, 2013, and June 29, 2015, we randomly assigned 602 women to induction with misoprostol (n=302) or the Foley catheter (n=300; intention-to-treat population). Vaginal birth within 24 h was more common in women in the misoprostol group than in the Foley catheter group (172 [57·0%] vs 141 [47·0%] women; absolute risk difference 10·0%, 95% CI 2·0–17·9; p=0·0136). Rates of uterine hyperstimulation were low in both the misoprostol and Foley catheter groups (two [0·7%] vs one [0·3%] cases; absolute risk difference 0·3%, 95% CI −0·8 to 1·5; p=0·566) and neonatal deaths did not differ significantly between groups (six [2·0%] vs three [1·0%] neonatal deaths; 1·0, −1·04 to 2·97; p=0·322). 17 serious adverse events (3%) were reported during the study: one case of intrapartum convulsion and one case of disseminated intravascular coagulation (both in the Foley group); ten perinatal deaths, including two stillbirths (both in the Foley catheter group) and eight neonatal deaths (n=5 in the misoprostol group and n=3 in the Foley catheter group); and five of neonatal morbidity, comprising birth asphyxia (n=3), septicaemia (n=1), and neonatal convulsion (n=1). Interpretation Oral misoprostol was more effective than transcervical Foley catheterisation for induction of labour in women with pre-eclampsia or hypertension. Future studies are required to assess whether oxytocin augmentation following misoprostol can be replaced by regular doses of oral misoprostol tablets

Introducing the participant-generated experience and satisfaction (PaGES) index: a novel, longitudinal mixed-methods evaluation tool

Background: Patient-Reported Outcomes or Experience Measures (PROMS / PREMS) are routinely used in clinical studies to assess participants’ views and experiences of trial interventions and related quality of life. Purely quantitative approaches lack the necessary detail and flexibility to understand the real-world impact of study interventions on participants, according to their own priorities. Conversely, purely qualitative assessments are time consuming and usually restricted to a small, possibly unrepresentative, sub-sample. This paper, which reports a pilot study within a randomised controlled trial of induction of labour, reports the feasibility, and acceptability of the Participant-Generated Experience and Satisfaction (PaGES) Index, a new mixed qualitative / quantitative PREM tool. Methods: The single-sheet PaGES Index was completed by hypertensive pregnant women in two hospitals in Nagpur, India before and after taking part in the ‘Misoprostol or Oxytocin for Labour Induction’ (MOLI) randomised controlled trial. Participants recorded aspects of the impending birth they considered most important, and then ranked them. After the birth, participants completed the PaGES Index again, this time also scoring their satisfaction with each item. Forms were completed on paper in the local language or in English, supported by Research Assistants. Following translation (when needed), responses were uploaded to a REDCap database, coded in Excel and analysed thematically. A formal qualitative evaluation (qMOLI) was also conducted to obtain stakeholder perspectives of the PaGES Index and the wider trial. Semi-structured interviews were conducted with participants, and focus groups with researchers and clinicians. Data were managed using NVivo 12 software and analysed using the framework approach. Results: Participants and researchers found the PaGES Index easy to complete and administer; mothers valued the opportunity to speak about their experience. Qualitative analysis of the initial 68 PaGES Index responses identified areas of commonality and difference among participants and also when comparing antenatal and postnatal responses. Theme citations and associated comments scores were fairly stable before and after the birth. The qMOLI phase, comprising 53 one-to-one interviews with participants and eight focus groups involving 83 researchers and clinicians, provided support that the PaGES Index was an acceptable and even helpful means of capturing participant perspectives. Conclusions: Subjective participant experiences are an important aspect of clinical trials. The PaGES Index was found to be a feasible and acceptable measure that unites qualitative research’s explanatory power with the comparative power of quantitative designs. It also offers the opportunity to conduct a before-and-after evaluation, allowing researchers to examine the expectations and actual experiences of all clinical trial participants, not just a small sub-sample. This study also shows that, with appropriate research assistant input, the PaGES Index can be used in different languages by participants with varying literacy levels. Trial registration: Clinical Trials.gov (21/11/2018) (NCT03749902)