A key challenge in the estimation of tropical arthropod species richness is the appropriate management of the large uncertainties associated with any model. Such uncertainties had largely been ignored until recently, when we attempted to account for uncertainty associated with model variables, using Monte Carlo analysis. This model is restricted by various assumptions. Here, we use a technique known as probability bounds analysis to assess the influence of assumptions about (1) distributional form and (2) dependencies between variables, and to construct probability bounds around the original model prediction distribution. The original Monte Carlo model yielded a median estimate of 6.1 million species, with a 90 % confidence interval of [3.6, 11.4]. Here we found that the probability bounds (p-bounds) surrounding this cumulative distribution were very broad, owing to uncertainties in distributional form and dependencies between variables. Replacing the implicit assumption of pure statistical independence between variables in the model with no dependency assumptions resulted in lower and upper p-bounds at 0.5 cumulative probability (i.e., at the median estimate) of 2.9-12.7 million. From here, replacing probability distributions with probability boxes, which represent classes of distributions, led to even wider bounds (2.4-20.0 million at 0.5 cumulative probability). Even the 100th percentile of the uppermost bound produced (i.e., the absolutely most conservative scenario) did not encompass the well-known hyper-estimate of 30 million species of tropical arthropods. This supports the lower estimates made by several authors over the last two decades.

BackgroundThere is conflicting information as to whether antiretroviral drugs with better central nervous system (CNS) penetration (neuroHAART) assist in improving neurocognitive function and suppressing cerebrospinal fluid (CSF) HIV RNA. The current review aims to better synthesise existing literature by using an innovative two-phase review approach (qualitative and quantitative) to overcome methodological differences between studies.MethodsSixteen studies, all observational, were identified using a standard citation search. They fulfilled the following inclusion criteria: conducted in the HAART era; sample size > 10; treatment effect involved more than one antiretroviral and none had a retrospective design. The qualitative phase of review of these studies consisted of (i) a blind assessment rating studies on features such as sample size, statistical methods and definitions of neuroHAART, and (ii) a non-blind assessment of the sensitivity of the neuropsychological methods to HIV-associated neurocognitive disorder (HAND). During quantitative evaluation we assessed the statistical power of studies, which achieved a high rating in the qualitative analysis. The objective of the power analysis was to determine the studies ability to assess their proposed research aims.ResultsAfter studies with at least three limitations were excluded in the qualitative phase, six studies remained. All six found a positive effect of neuroHAART on neurocognitive function or CSF HIV suppression. Of these six studies, only two had statistical power of at least 80%.ConclusionsStudies assessed as using more rigorous methods found that neuroHAART was effective in improving neurocognitive function and decreasing CSF viral load, but only two of those studies were adequately statistically powered. Because all of these studies were observational, they represent a less compelling evidence base than randomised control trials for assessing treatment effect. Therefore, large randomised trials are needed to determine the robustness of any neuroHAART effect. However, such trials must be longitudinal, include the full spectrum of HAND, ideally carefully control for co-morbidities, and be based on optimal neuropsychology methods.

The Epworth Sleepiness Scale is used frequently to measure excessive daytime sleepiness in research and clinical settings, although there is limited evidence on test–retest reliability, particularly among sleep clinic populations. The objective of this study was to evaluate the reliability of this instrument among adult patients recruited from a public hospital sleep clinic in Sydney, Australia. English‐speaking participants self‐completed the Epworth Sleepiness Scale on two occasions, at the specialist clinic visit and on the night of diagnostic polysomnography. Of the 108 participants included in the study, the majority were male (64%) and the mean age was 51 years. The median retest interval was 64 days. The primary outcome of test–retest reliability as measured using the intraclass correlation coefficient was 0.73 (95% confidence interval, 0.61–0.82). Despite moderate statistical reliability and a low mean difference of 1.1, Bland‐Altman analysis showed an unacceptably wide distribution of between‐score differences. The 95% limits of agreement were −8.5 to +10.6, and an absolute difference in scores of at least 3 was observed in 60 (56%) of the participants. Our results suggest that the Epworth Sleepiness Scale should not be used in clinical settings to make individual‐level comparisons, such as the effect of therapeutic interventions, or to prioritise access to services.

Background In 2001, the Department of Health produced the Improving Working Lives (IWL) for Doctors document. This is the first national survey which asks hospital doctors what changes are needed to improve their working lives. Methods An online questionnaire was run over a period of six weeks and was open to all doctors of all grades. Doctors were asked to choose their top five factors from a list of 35 diverse choices or to provide alternatives in free text. Demographic data were also collected. Results 1603 hospital doctors working in the UK completed the online questionnaire. Improved secretarial or managerial support was the first IWL choice for consultants, with different aspects of clinical and non-clinical support representing their top four choices. Junior hospital doctors and staff and associate specialist grades (staff grades, associate specialists, and clinical assistants) identified improved support for education and training as their first choice, while among the female specialist registrars, it was improved support for childcare. Greater opportunities to develop new skills was an important issue for doctors in the surgical specialties and improved access to mentoring was important for all junior doctors, staff and associate specialist grades, and doctors from black and ethnic minority groups. Conclusions Hospital doctors in the UK need more support to improve their working lives. The principle needs are better secretarial and managerial support for consultants; education, training, and mentoring for junior doctors and staff and associate specialist grades; and improved opportunities to develop new skills for those in surgical specialties. Support with childcare is an important issue for female specialist registrars. The Department of Health, NHS trusts, deaneries, and Royal Colleges need to endorse policies that promote a training and working environment that will improve working lives for all hospital doctors, ensuring that appropriate and continuing support is available from the time doctors enter the new foundation programmes and proposed run-through grades, to their time spent as consultants in today’s NHS.