Retrospective observational study of the impact on emergency admission of telehealth at scale delivered in community care in Liverpool, UK.

OBJECTIVE: To assess the effect of a real world, ongoing telehealth service on the use of secondary healthcare. DESIGN: A retrospective observational study with anonymous matched controls. SETTING: Primary and community healthcare. Patients were recruited over 4 years in 89 general practices in Liverpool, UK and remotely managed by a dedicated clinical team in Liverpool Community Health. PARTICIPANTS: 5154 patients with chronic obstructive pulmonary disease, heart failure or diabetes were enrolled in the programme, of whom 3562 satisfied the inclusion criteria of this study. INTERVENTION: At least 9 weeks of telehealth including vital sign collection, questionnaires, education, support and informal coaching by clinical staff. PRIMARY OUTCOME: Reduction in the number of emergency admissions in the 12 months after start, compared with the year before start. Secondary subgroup analysis to improve future targeting and personalisation of the service. RESULT: The average number of emergency admissions for the intervention group at baseline is 0.35, 95% CI 0.32 to 0.38. The differential decrease in emergency admissions in the intervention group in comparison with the control group, the average treatment effect, is 0.08, 95 CI 0.05 to 0.11, corresponding to an average percentage decrease of 22.7%. In subgroup analysis, a score is calculated that can be used prospectively to predict individual benefit from the intervention. Patients with an above median score (37%) are predicted average reduction in emergency admissions of 0.15, 95% CI 0.09 to 0.2, corresponding to a percentage decrease in admissions of 25.3%. CONCLUSION: The telehealth intervention has a positive impact across a wide cohort of patients with different diseases. Prospective scoring of patients and allocation to targeted telehealth interventions is likely to improve the effectiveness and efficiency of the service.

Comparison of venous and capillary differential leukocyte counts using a standard hematology analyzer and a novel microfluidic impedance cytometer.

Capillary blood sampling has been identified as a potentially suitable technique for use in diagnostic testing of the full blood count (FBC) at the point-of-care (POC), for which a recent need has been highlighted. In this study we assess the accuracy of capillary blood counts and evaluate the potential of a miniaturized cytometer developed for POC testing. Differential leukocyte counts in the normal clinical range from fingerprick (capillary) and venous blood samples were measured and compared using a standard hematology analyzer. The accuracy of our novel microfluidic impedance cytometer (MIC) was then tested by comparing same-site measurements to those obtained with the standard analyzer. The concordance between measurements of fingerprick and venous blood samples using the standard hematology analyzer was high, with no clinically relevant differences observed between the mean differential leukocyte counts. Concordance data between the MIC and the standard analyzer on same-site measurements presented significantly lower leukocyte counts determined by the MIC. This systematic undercount was consistent across the measured (normal) concentration range, suggesting that an internal correction factor could be applied. Differential leukocyte counts obtained from fingerprick samples accurately reflect those from venous blood, which confirms the potential of capillary blood sampling for POC testing of the FBC. Furthermore, the MIC device demonstrated here presents a realistic technology for the future development of FBC and related tests for use at the site of patient care.

Microfluidic lysis of human blood for leukocyte analysis using single cell impedance cytometry.

This paper demonstrates an integrated microfluidic system that performs a full blood count using impedance analysis. A microfluidic network design for red blood cell (RBC) lysis is presented, and the diffusive mixing processes are analyzed using experimental and simulated results. Healthy and clinical bloods analyzed with this system, and the data shows good correlation against data obtained from commercial hematology machines. The data from the microfluidic system was compared against hospital data for 18 clinical samples, giving R(2) (coefficient of determination) values of 0.99 for lymphocytes, 0.89 for monocytes, and 0.99 for granulocytes in terms of relative counts and 0.94 for lymphocytes, 0.91 for monocytes, and 0.95 for granulocytes in terms of absolute counts. This demonstrates the potential clinical utility of this new system for a point-of-care purpose.

Integrated systems for rapid point of care (PoC) blood cell analysis.

Counting the different subpopulations of cells in a fingerprick of human blood is important for a number of clinical point-of-care (PoC) applications. It is a challenge to demonstrate the integration of sample preparation and detection techniques in a single platform. In this paper we demonstrate a generic microfluidic platform that combines sample processing and characterisation and enumeration in a single, integrated system. Results of microfluidic 3-part differential leukocyte (granulocyte, lymphocyte and monocyte) counts, together with erythrocyte and thrombocyte (platelet) counts, in human blood are shown and corroborated with results from hospital clinical laboratory analysis.

Effect of the structure of cholesterol-based tethered bilayer lipid membranes on ionophore activity.

Tethered bilayer lipid membranes (tBLM) are formed on 1) pure tether lipid triethyleneoxythiol cholesterol (EO(3)C) or on 2) mixed self-assembled monolayers (SAMs) of EO(3)C and 6-mercaptohexanol (6MH). While EO(3)C is required to form a tBLM with high resistivity, 6MH dilutes the cholesterol content in the lower leaflet of the bilayer forming ionic reservoirs required for submembrane hydration. Here we show that these ionic reservoirs are required for ion transport through gramicidin or valinomycin, most likely due to the thermodynamic requirements of ions to be solvated once transported through the membrane. Unexpectedly, electrochemical impedance spectroscopy (EIS) shows an increase of capacitance upon addition of gramicidin, while addition of valinomycin decreases the membrane resistance in the presence of K(+) ions. We hypothesise that this is due to previously reported phase separation of EO(3)C and 6MH on the surface. This results in ionic reservoirs on the nanometre scale, which are not fully accounted for by the equivalent circuits used to describe the system.

Leukocyte analysis and differentiation using high speed microfluidic single cell impedance cytometry.

Miniature high speed label-free cell analysis systems have yet to be developed, but have the potential to deliver fast, inexpensive and simple full blood cell analysis systems that could be used routinely in clinical practice. We demonstrate a microfluidic single cell impedance cytometer that performs a white blood cell differential count. The device consists of a microfluidic chip with micro-electrodes that measure the impedance of single cells at two frequencies. Human blood, treated with saponin/formic acid to lyse erythrocytes, flows through the device and a complete blood count is performed in a few minutes. Verification of cell dielectric parameters was performed by simultaneously measuring fluorescence from CD antibody-conjugated cells. This enabled direct correlation of impedance signals from individual cells with phenotype. Tests with patient samples showed 95% correlation against commercial (optical/Coulter) blood analysis equipment, demonstrating the potential clinical utility of the impedance microcytometer for a point-of-care blood analysis system.