Impact of NHS walk-in centres on the workload of other local healthcare providers: time series analysis

ObjectivesTo assess the impact of NHS walk-in centres on the workload of local accident and emergency departments, general practices, and out of hours services.DesignTime series analysis in walk-in centre sites with no-treatment control series in matched sites.SettingWalk-in centres and matched control towns without walk-in centres in England.Participants20 accident and emergency departments, 40 general practices, and 14 out of hours services within 3 km of a walk-in centre or the centre of a control town.ResultsA reduction in consultations at emergency departments (–175 (95% confidence interval –387 to 36) consultations per department per month) and general practices (–19.8 (−53.3 to 13.8) consultations per 1000 patients per month) close to walk-in centres became apparent, although these reductions were not statistically significant. Walk-in centres did not have any impact on consultations on out of hours services.ConclusionIt will be necessary to assess the impact of walk-in centres in a larger number of sites and over a prolonged period, to determine whether they reduce the demand on other local NHS providers.

What is already known on this topic

One of the objectives for NHS walk-in centres was to reduce demand on other NHS services, particularly general practitioners'' services and accident and emergency departmentsStudies of walk-in centres in North America have indicated that such centres do not reduce demand on other healthcare servicesStudies of minor injuries units in the United Kingdom (which have some similarities with walk-in centres) indicate that these units substitute mainly for consultations in accident and emergency departments

What this study adds

The data imply that walk-in centres may moderate the increasing demand on general practice and reduce the number of consultations in accident and emergency departmentsThe high level of background variability in consultation rates means that any impact of a walk-in centre is not statistically significantTo draw robust conclusions about the impact of walk-in centres on other health providers will require study of a large number of sites over an extended period of time     

Effect of NHS walk-in centre on local primary healthcare services: before and after observational study

ObjectiveTo assess the effect of an NHS walk-in centre on local primary and emergency healthcare services.DesignBefore and after observational study.SettingLoughborough, which had an NHS walk-in centre, and Market Harborough, the control town.Participants12 general practices.ResultsThe change between the before and after study periods was not significantly different in the two towns for daily rate of emergency general practice consultations (mean difference −0.02/1000 population, 95% confidence interval −0.75 to 0.71), the time to the sixth bookable routine appointment (−0.24 half-days, −1.85 to 1.37), and daily rate of attendances at out of hours services (0.07/1000 population, −0.06 to 0.19). However, attendance at the local minor injuries unit was significantly higher in Loughborough than Market Harborough (rate ratio 1.22, 1.12 to 1.33). Non-ambulance attendances at accident and emergency departments fell less in Loughborough than Market Harborough (rate ratio 1.17, 1.03 to 1.33).ConclusionsThe NHS walk-in centre did not greatly affect the workload of local general practitioners. However, the workload of the local minor injuries unit increased significantly, probably because it was in the same building as the walk-in centre.

What is already known on this topic

Walk-in centres are well established in North America but differ from NHS centres as they are run by doctors not nurses

What this study adds

Introduction of an NHS walk-in centre did not affect the workload of local general practitionersAttendance increased at the minor injuries unit, which was in the same buildingNon-ambulance attendances at accident and emergency departments decreased but not by as much as in the control area     

How to fail at species delimitation

Species delimitation is the act of identifying species‐level biological diversity. In recent years, the field has witnessed a dramatic increase in the number of methods available for delimiting species. However, most recent investigations only utilize a handful (i.e. 2–3) of the available methods, often for unstated reasons. Because the parameter space that is potentially relevant to species delimitation far exceeds the parameterization of any existing method, a given method necessarily makes a number of simplifying assumptions, any one of which could be violated in a particular system. We suggest that researchers should apply a wide range of species delimitation analyses to their data and place their trust in delimitations that are congruent across methods. Incongruence across the results from different methods is evidence of either a difference in the power to detect cryptic lineages across one or more of the approaches used to delimit species and could indicate that assumptions of one or more of the methods have been violated. In either case, the inferences drawn from species delimitation studies should be conservative, for in most contexts it is better to fail to delimit species than it is to falsely delimit entities that do not represent actual evolutionary lineages.     

L-selectin dimerization enhances tether formation to properly spaced ligand

Selectin counterreceptors are glycoprotein scaffolds bearing multiple carbohydrate ligands with exceptional ability to tether flowing cells under disruptive shear forces. Bond clusters may facilitate formation and stabilization of selectin tethers. L-selectin ligation has been shown to enhance L-selectin rolling on endothelial surfaces. We now report that monoclonal antibodies-induced L-selectin dimerization enhances L-selectin leukocyte tethering to purified physiological L-selectin ligands and glycopeptides. Microkinetic analysis of individual tethers suggests that leukocyte rolling is enhanced through the dimerization-induced increase in tether formation, rather than by tether stabilization. Notably, L-selectin dimerization failed to augment L-selectin-mediated adhesion below a threshold ligand density, suggesting that L-selectin dimerization enhanced adhesiveness only to properly clustered ligand. In contrast, an epidermal growth factor domain substitution of L-selectin enhanced tether formation to L-selectin ligands irrespective of ligand density, suggesting that this domain controls intrinsic ligand binding properties of L-selectin without inducing L-selectin dimerization. Strikingly, at low ligand densities, where L-selectin tethering was not responsive to dimerization, elevated shear stress restored sensitivity of tethering to selectin dimerization. This is the first indication that shear stress augments effective selectin ligand density at local contact sites by promoting L-selectin encounter of immobilized ligand.