Respondent driven sampling (RDS) is an important tool for measuring disease prevalence in populations with no sampling frame. We aim to describe key properties of these samples to guide those using this method and to inform methodological research.
In 2019, authors who published respondent driven sampling studies were contacted with a request to share reported degree and network information. Of 59 author groups identified, 15 (25%) agreed to share data, representing 53 distinct study samples containing 36,547 participants across 12 countries and several target populations including migrants, sex workers and men who have sex with men. Distribution of reported network degree was described for each sample and characteristics of recruitment chains, and their relationship to coupons, were reported.
Reported network degree is severely skewed and is best represented by a log normal distribution. For participants connected to more than 15 other people, reported degree is imprecise and frequently rounded to the nearest five or ten. Our results indicate that many samples contain highly connected individuals, who may be connected to at least 1000 other people.
Because very large reported degrees are common; we caution against treating these reports as outliers. The imprecise and skewed distribution of the reported degree should be incorporated into future RDS methodological studies to better capture real-world performance. Previous results indicating poor performance of regression estimators using RDS weights may be widely generalizable. Fewer recruitment coupons may be associated with longer recruitment chains.

Web-based respondent-driven sampling is a novel sampling method for the recruitment of participants for generating population estimates, studying social network characteristics, and delivering health interventions. However, the application, barriers and facilitators, and recruitment performance of web-based respondent-driven sampling have not yet been systematically investigated.
Our objectives were to provide an overview of published research using web-based respondent-driven sampling and to investigate factors related to the recruitment performance of web-based respondent-driven sampling.
We conducted a scoping review on web-based respondent-driven sampling studies published between 2000 and 2019. We used the process evaluation of complex interventions framework to gain insights into how web-based respondent-driven sampling was implemented, what mechanisms of impact drove recruitment, what the role of context was in the study, and how these components together influenced the recruitment performance of web-based respondent-driven sampling.
We included 18 studies from 8 countries (high- and low-middle income countries), in which web-based respondent-driven sampling was used for making population estimates (n=12), studying social network characteristics (n=3), and delivering health-related interventions (n=3). Studies used web-based respondent-driven sampling to recruit between 19 and 3448 participants from a variety of target populations. Studies differed greatly in the number of seeds recruited, the proportion of successfully recruiting participants, the number of recruitment waves, the type of incentives offered to participants, and the duration of data collection. Studies that recruited relatively more seeds, through online platforms, and with less rigorous selection procedures reported relatively low percentages of successfully recruiting seeds. Studies that did not offer at least one guaranteed material incentive reported relatively fewer waves and lower percentages of successfully recruiting participants. The time of data collection was shortest in studies with university students.
Web-based respondent-driven sampling can be successfully applied to recruit individuals for making population estimates, studying social network characteristics, and delivering health interventions. In general, seed and peer recruitment may be enhanced by rigorously selecting and motivating seeds, offering at least one guaranteed material incentive, and facilitating adequate recruitment options regarding the target population\'s online connectedness and communication behavior. Potential trade-offs should be taken into account when implementing web-based respondent-driven sampling, such as having less opportunities to implement rigorous seed selection procedures when recruiting many seeds, as well as issues around online rather than physical participation, such as the risk of cheaters participating repeatedly.

Coronavirus Disease 2019 (COVID-19) is a pandemic disease that increased the burden on health-care system. In the Kingdom of Saudi Arabia, 74,795 cases have been reported until 26 May 2020 and the number of cases is rapidly increasing. The mortality rate of COVID-19 worldwide is 6.37%. Here we report three cases of acute kidney injury (AKI) secondary to pneumonia of severe COVID-19; they were treated with automated peritoneal dialysis (PD) with full recovery. To the best of our knowledge, few reports in the literature have discussed the use of PD in AKI secondary to COVID-19.

Substandard and falsified (SF) medicines are a global issue contributing to antimicrobial resistance and causing economic and humanitarian harm. To direct law enforcement efficiently, halt the spread of SF medicines and antimicrobial resistance, academics, NGOs and government organisations use medicine quality sampling studies to estimate the prevalence of the problem. A systematic review of medicine quality studies was conducted to estimate how the methodological quality of these studies and SF prevalence has changed between 2013 and 2018. We also aimed to critique medicine sampling study methodologies, and the systematic review process which generates prevalence estimates. Based on 33 studies, the overall estimated median (Q1-Q3) prevalence of SF medicines appears to have remained high at 25% (7.7%-34%) compared with 28.5% in 2013. Furthermore, the methodological quality of prevalence studies has improved over the last 25 years. Definitive conclusions regarding the prevalence of SF medicines cannot be drawn due to the variability in sample sizes, consistency of design methods, and a lack of information concerning contextual factors affecting medicine quality studies. We contend that studies which present cumulative average prevalence figures are useful in a broad sense but could be improved to create more reliable estimates. We propose that medicine quality studies record the context of the study environment to allow systematic reviewers to compare like with like. Although, the academic rigour of medicine quality studies is improving, medicine sampling study limitations still exist. These limitations inhibit the accurate estimation of SF medicine prevalence which is needed to support detailed policy changes.

This literature review provides an overview of use of environmental samples (ES) such as faeces, water, air, mud and swabs of surfaces in avian influenza (AI) surveillance programs, focussing on effectiveness, advantages and gaps in knowledge. ES have been used effectively for AI surveillance since the 1970s. Results from ES have enhanced understanding of the biology of AI viruses in wild birds and in markets, of links between human and avian influenza, provided early warning of viral incursions, allowed assessment of effectiveness of control and preventive measures, and assisted epidemiological studies in outbreaks, both avian and human. Variation exists in the methods and protocols used, and no internationally recognized guidelines exist on the use of ES and data management. Few studies have performed direct comparisons of ES versus live bird samples (LBS). Results reported so far demonstrate reliance on ES will not be sufficient to detect virus in all cases when it is present, especially when the prevalence of infection/contamination is low. Multiple sample types should be collected. In live bird markets, ES from processing/selling areas are more likely to test positive than samples from bird holding areas. When compared to LBS, ES is considered a cost-effective, simple, rapid, flexible, convenient and acceptable way of achieving surveillance objectives. As a non-invasive technique, it can minimize effects on animal welfare and trade in markets and reduce impacts on wild bird communities. Some limitations of environmental sampling methods have been identified, such as the loss of species-specific or information on the source of virus, and taxonomic-level analyses, unless additional methods are applied. Some studies employing ES have not provided detailed methods. In others, where ES and LBS are collected from the same site, positive results have not been assigned to specific sample types. These gaps should be remedied in future studies.

OBJECTIVE: To assess the impact of a 2015 reform to the Mental Health Act 2007 (NSW) (MHA) that was interpreted as requiring a reference to decision-making capacity (DMC) in reports to the NSW Mental Health Review Tribunal (MHRT).
METHODS: A sample of reports to the MHRT were audited for references to the MHA\'s treatment criteria and DMC in periods before and after the reforms, and the frequency of references between the two periods was compared.
RESULTS: The frequency of references to DMC did not change significantly after the reforms. (However, references to the \'least restriction\' criterion increased markedly between the two periods).
CONCLUSIONS: Despite legislative reforms and a supporting education campaign promoting the importance of consideration of DMC, references to DMC did not increase after the reforms.

Respondent-driven sampling (RDS) is a successful data collection method used in hard-to-reach populations, like those experiencing or at high risk of drug dependence. Since its introduction in 1997, identifying appropriate methods for estimating population means and sampling variances has been challenging and numerous approaches have been developed for making inferences about these quantities. To guide researchers and practitioners in deciding which approach to use, this article reviews the literature on these methodological developments.
A systematic review using four electronic databases was conducted in order to summarize the progress of RDS inference over the last 20 years and to provide insight to researchers on using the appropriate estimators in analyzing RDS data. Two independent reviewers selected the relevant abstracts and articles; thirty-two studies were included. The content of the studies was further categorized into developing and evaluating RDS mean and variance estimators.
The population mean estimator RDSIEGO and the sampling variance estimators associated with tree boot strapping were identified as promising methods as the most robust population mean and variance estimate, respectively; as these estimators rely on a fewer assumptions.
RDS holds substantial promise as a sampling method for understanding populations at high risk. The varied approaches to inference with RDS data each rely on different assumptions, but some require fewer assumptions than others and provide more robust and accurate inferences, when their corresponding assumptions are met.

Fluorescence in the ventricular wall or the ependyma during fluorescence-guided resection (FGR) of malignant glioma is commonly observed when malignant gliomas infiltrate the ventricles. However, the underlying pathophysiology and clinical importance are largely unknown but may play a role in deciding whether to continue resection into the ventricles or not. Here, we systematically review available data regarding ependymal fluorescence in FGR using five aminolevulinic acid (5-ALA) and sodium fluorescein (SF).
A literature search on MEDLINE, EMBASE, and WEB OF SCIENCE was performed using the following headings and search operators: ependy* fluorescence AND (5-ALA OR five aminolevulinic acid), ventric* wall fluorescence AND (5-ALA OR five aminolevulinic acid), ependy* fluorescence AND fluorescein, and ventric* wall fluorescence AND fluorescein. Both authors analyzed abstracts independently. Included articles were further reviewed for prevalence of ependymal fluorescence, patterns of fluorescence, and histopathological characteristics of sampled tissues as well as radiological signs of ependymal fluorescence. Results are reported according to the PRISMA statement.
Of 202 records identified, 6 studies were included compiling a total number of 198 patients treated with FGR using 5-ALA. No study on ependymal fluorescence after administration of SF was found. Overall prevalence of ependymal fluorescence was 61.4%. A total of 54.5% of cases were found to be positive for tumor cells. A total of 25.5% of patients with ependymal fluorescence were related to contrast enhancement in ventricular walls.
The phenomenon of ventricular wall fluorescence in 5-ALA-derived fluorescence-guided resection of malignant glioma is poorly understood and not always may fluorescence represent tumor infiltration. A larger scale prospective sampling study with molecular analyses is currently ongoing and will hopefully provide further insight into pathophysiology and clinical implications of ependymal fluorescence.

Respondent-driven sampling (RDS) is an increasingly popular method of recruiting participants from hard-to-reach populations and has traditionally been used to estimate the prevalence of HIV among marginalized people. The STROBE-RDS guidelines were published in 2015 to improve the reporting of these studies. We aim to determine the current applications of RDS and the quality of reporting of these studies.
The SCOPUS, PubMed, and CINAHL databases were used to find papers published in 2017, relating to RDS. Papers meeting the inclusion criteria of cross-sectional studies using RDS were classified according to the study outcome and target population. A random sample of 25 papers was selected to evaluate the quality of reporting using the STROBE-RDS guidelines.
Men who have sex with men, people who inject drugs, and female sex workers were the most common populations for RDS studies; over half of the studies examined the HIV epidemic. Quality of reporting is good with respect to the original STROBE guidelines but is generally weaker with respect to RDS-specific aspects of the study, including recruitment and statistical analysis.
Most authors are using RDS appropriately and aware of the need for statistical adjustments to RDS data. Nonetheless, the STROBE-RDS guidelines should be more widely disseminated to promote better reporting of key aspects of RDS studies.

The recently published 2016 revision of the WHO classification of lymphoid neoplasms includes primary cutaneous acral CD8-positive T-cell lymphoma (PCATCL) as a provisional entity. This is a rare indolent lymphoma characterized by papules or nodules on the ear and a dermal infiltrate of CD8-positive T-lymphocytes with cytotoxic marker expression. A retrospective review of a single institutional experience with PCATCL identified 3 patients (mean age 54; range 49-62) with papules or nodules on the ear. Lesional biopsies demonstrated a dense diffuse dermal infiltrate of atypical lymphocytes with a Grenz zone in 2 cases and focal epidermotropism in 1 case. The atypical lymphocytes were predominantly CD3 and CD8 positive with expression of cytotoxic marker TIA1. Staging evaluation failed to reveal systemic disease. Two patients underwent local excision, and the third received local radiation therapy all with complete response and no disease recurrence at last follow-up 3 months (range 2-5 months). Our cases add to the existing limited literature on the clinical and histopathological features of PCATCL. We also performed an updated systematic literature view of the entity.