Transport of serum proteins from the circulation to peritoneal dialysate in peritoneal dialysis patients mainly focused on total protein. Individual proteins have hardly been studied. We determined serum and effluent concentrations of four individual proteins with a wide molecular weight range routinely in the standardised peritoneal permeability analysis performed yearly in all participating patients. These include β2-microglobulin, albumin, immunoglobulin G and α2-macroglobulin. The dependency of transport of these proteins on their molecular weight and diffusion coefficient led to the development of the peritoneal protein restriction coefficient (PPRC), which is the slope of the relation between the peritoneal clearances of these proteins and their free diffusion coefficients in water, when plotted on a double logarithmic scale. The higher the PPRC, the more size restriction to transport. In this review, we discuss the results obtained on the PPRC under various conditions, such as effects of various osmotic agents, vasoactive drugs, peritonitis and the hydrostatic pressure gradient. Long-term follow-up of patients shows an increase of the PPRC, the possible causes of which are discussed. Venous vasculopathy of the peritoneal microcirculation is the most likely explanation.

Rheumatoid Arthritis (RA) is a chronic disease that impacts patients’ quality of life. Sophisticated organization of care delivery drives quality improvement. Therefore, the study objective was establishing a validated process map of the care cycle for RA patients. Hence, increasing transparency and optimizing care delivery and identifying areas of improvement. To map the RA care cycle, the care delivery value chain (CDVC) approach was used as framework to document activities and resources systematically. A mixed method study was conducted where quantitative data on activities were collected from health records and unstructured interviews with medical staff were held. Consequently, the process map was separately validated in a consensus meeting with a delegation of the medical staff and patient advisory board. At the start of the care cycle, the focus is predominantly on defining the treat-to-target strategy and examining disease activity. Towards the monitoring phase, tapering medication and managing the disease through patient-reported outcome measures are becoming increasingly important. Although patient’s functioning, quality of care and patient’s evaluation of received care are monitored, reflection of CDVC and engaging patients in the evaluation process resulted in improvement actions on outcome and process level. Mapping the RA care cycle following a systematic approach, provides insight and transparency in delivered activities, involved resources and the engagement of patients and caregivers at multiple levels, contributing to a system facilitating value-based care delivery. The CDVC framework and applied methodology is recommended in other conditions. Future research will focus at assigning outcomes and costs to activities and evaluating interventions to explore patient value.

Background:The Rotterdam Early Arthritis Cohort (REACH) rule [1] and Clinical Arthritis RulE (CARE) [2] are both evidence-based and easy-to-use methods developed to identify the presence of inflammatory arthritis (IA) in patients suspected by their general practitioner (GP). However, the clinical utility of both models in daily clinical practice in an independent primary care setting has not yet been established. While developed for recognizing IA, we believe that it is also important that the broader spectrum of inflammatory rheumatic diseases (IRDs) is correctly classified from primary care, to facilitate appropriate referral towards outpatient rheumatology clinics.Objectives:The primary objective was to determine the diagnostic performance and clinical utility of the REACH and CARE referral rules in identifying IA in an independent population of unselected suspected patients from primary care. Secondly we will assess the diagnostic performance and clinical utility of both models in identifying IRDs.Methods:This prospective observational diagnostic study consisted of adults newly suspected by their GP for the need of referral to the rheumatology outpatient clinic of the Maasstad Hospital in Rotterdam. Primary outcome was IA, consisting of rheumatoid arthritis, axial spondylitis and psoriatic arthritis. Secondary outcome was IRD, defined as IA plus arthritis in systemic disorders such as systemic lupus erythematosus, systemic sclerosis and morbus sjögren. Rheumatologist diagnosis was used as gold standard. To evaluate the clinical performance of the REACH and CARE referral rules in this population, diagnostic accuracy measures were investigated using the Youden index (J) [3]. Moreover, a net benefit approach [4] was used to determine clinical utility of both rules when compared to usual care.Results:This study consisted of 250 patients (22.8% male) with a mean age of 50.8 years (SD 13.9 years). In total 42 (17%) patients were diagnosed with IA and 55 (22%) with an IRD. Figure 1 presents the diagnostic performance in IA (Figure 1A) and in IRD (Figure 1B). For the primary outcome, the REACH model shows an AUC of 0.72 (95% CI 0.64-0.80) and the optimal cut-off point is indicated (J). The CARE model shows an AUC of 0.82 (95% CI 0.75-0.88) and at J there is a somewhat higher sensitivity and specificity. When taking the broader spectrum of IRDs as outcome, the AUC was 0.66 (95% CI 0.58-0.74) for the REACH and 0.76 (95% CI 0.69-0.83) for the CARE model. The net benefit analysis with either IA or IRD as outcome showed that the CARE was of the highest clinical value when compared to usual care.Conclusion:Both the REACH and CARE model showed a good diagnostic performance for detecting IA in an independent population of unselected suspected patients from primary care. Although not specifically developed to recognize the entire spectrum of IRDs, the CARE shows a good performance in doing so. When evaluating clinical utility, we see that both rules have a net benefit in recognizing IA as well as IRDs compared to usual care, however the CARE shows superiority over the REACH. By using the CARE, over half of all suspected patients can be withheld from expensive outpatient rheumatology care, implied by the high specificity of 70%. These results support the idea that incorporating these easy-to-use methods into primary care could lead to providing patients the right care at the right place and improving value based health care.References:[1]ten Brinck RM, van Dijk BT, van Steenbergen HW, le Cessie S, Numans ME. Development and validation of a clinical rule for recognition of early inflammatory arthritis. BMJ Open; 2018: 8[2]Alves, C. Improving early referral of inflammatory arthritis. In Early detection of patients at risk for rheumatoid arthritis – a challenge for primary and secondary care; 2015: 27-38 Ridderkerk, the Netherlands.[3]Fluss R, Faraggi D, Reiser B. Estimation of the Youden Index and its associated cutoff point. Biom J; 2005: 47(4): 458-472[4]Vickers AJ, Elkin EB. Decision curve analysis: a novel method for evaluating prediction models. Med Decis Making; 2006: 26(6): 565-574Disclosure of Interests:None declared

ObjectivesTo classify patients with rheumatoid arthritis (RA) in an earlier stage of the disease, the ACR/EULAR classification criteria were updated in 2010. These criteria might have led to an increased incidence of RA in the rheumatology clinic. Since a higher incidence increases the socio-economic burden of RA, it is worthwhile to evaluate whether there is a time effect.Materials and methodsA systematic review was conducted using Embase, Medline Ovid, Cochrane Central, and Web of Science from database inception to February 2021. Included were only articles that addressed incidence rates of rheumatoid arthritis from rheumatology outpatient clinics.ResultsOf the 6,289 publications only 243 publications on RA were found eligible for full-text review. Nine studies were included reporting incidence. The pooled incidence for RA was 11% (95% CI 6–16%) per year. Over time the incidence increased after the introduction of the 2010 ACR/EULAR classification criteria. Overall there was a high intragroup heterogeneity (I2 = 97.93%, p < 0.001), caused by geographical area, study design and differences in case definitions.ConclusionAlthough the incidence seems to increase after the introduction of the 2010 ACR/EULAR criteria, no conclusions can be drawn on this time effect due to heterogeneity.

Background:Western countries experience an increasing demand for care, particularly for inflammatory arthritis (IA), while the healthcare budget decreases1. The innovative value-based primary care strategy2includes integrated care networks, where primary and secondary care bundle their expertise to improve patient value by providing the right care at the right place.General practitioners (GPs) have difficulties recognising IA, leading up to only 20% IA diagnoses of all newly referred arthralgia patients. However, since IA needs to be treated as early as possible to overcome progression, it is worthwhile to analyse whether integrated care networks have an impact on patient outcomes and cost-effectiveness. Triage by a rheumatologist in a primary care setting is one of the most promising integrated care networks for efficient referrals3.Objectives:To assess the effect of triage by a rheumatologist in a primary care setting in patients suspect for inflammatory arthritis.Methods:The present study follows a cluster randomized controlled trial design. The intervention, triage by a rheumatologist in a local primary care centre, will be compared to usual care. Usual care means that patients are referred to a rheumatology outpatient clinic based on the opinion of the general practitioner.The primary outcome is the frequency of IA diagnoses assessed by a rheumatologist. Patient reported outcome measures (PROMs (EQ-5D)) and costs (work productivity (iPCQ) and healthcare utilization (iMCQ)) were determined at baseline, after three, six and twelve months. The target was to include 267 patients for each study group (power level 0.8). Since this study is still ongoing we can only show first results on the efficiency of referrals.Results:In the period between February 2017 and December 2019 a total of 543 participants were included; 275 in the usual care group and 268 in the triage group. Mean age (51.3 ± 14.6 years) and percentage of men (23.6%) were comparable between groups (page=0.139; psex=0.330).The preliminary data show that the number of referred patients in the triage group is n=28 (10.5%) (Fig. 1). 32 patients (11.9%) were not referred directly but advice was given for additional diagnostics. Since all patients in the usual care group were referred there is a decrease of at least 77.6% in referrals when rheumatologists are participating in the integrated practice units.Preliminary data on diagnosis are available for all referred patients in the triage group and for n=137 (49.8%) in the usual care group at this point. In the triage group n=18 (64.2%) of referred patients were diagnosed with IA (6.7% of the total study population). In the usual care group this was n=52 (38.0%) of the patients yet diagnosed.Conclusion:These preliminary results of an integrated care network are promising. Approximately three-quarters of all patients can be withheld from expensive outpatient care. PROMs data and cost-effectiveness analysis will give clear answers in order to provide evidence whether this integrated care network can be implemented as a standard of care.References:[1] Rijksoverheid. (2018). Bestuurlijk akkoord medisch-specialistische zorg 2019 t/m 2022.https://www.rijksoverheid.nl/.[2] Porter ME, Pabo EA, Lee TH. (2013). Redesigning Primary Care: a strategic vision to improve value by organizing around patients’ needs. Health affairs, 32(3);516-525[3] Akbari A, et al. (2008). Interventions to improve outpatient referrals from primary care to secondary care. Cochrane Database Syst Rev, 4,CD005471.Disclosure of Interests:None declared