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Many physical-layer security works in the literature rely on purely theoretical work or simulated results to establish the value of physical-layer security in securing communications. We consider the secrecy capacity of a wireless Gaussian wiretap channel using channel sounding measurements to analyze the potential for secure communication in a real-world scenario. A multi-input, multi-output, multi-eavesdropper (MIMOME) system is deployed using orthogonal frequency division multiplexing (OFDM) over an 802.11n wireless network. Channel state information (CSI) measurements were taken in an indoor environment to analyze time-varying scenarios and spatial variations. It is shown that secrecy capacity is highly affected by environmental changes, such as foot traffic, network congestion, and propagation characteristics of the physical environment. We also present a numerical method for calculating MIMOME secrecy capacity in general and comment on the use of OFDM with regard to calculating secrecy capacity.
RESUMO
The UK has a significant and growing population of older adults with frailty and complex healthcare needs, necessitating innovative care solutions. This study aimed to explore patients' and carers' experiences of a novel integrated service that was set up to address the increasing healthcare needs of older people living with frailty. A qualitative study that combined free-text survey questions with in-depth interviews. This study is part of a larger non-randomized trial of the service, with evaluation of wellbeing and quality of life at baseline, 2 to 4 weeks, and 10 to 14 weeks. Patients (aged 65 and above) with an electronic Frailty Index in the severe range and their informal family carers participated in this study. Data were collected between April 2019 and March 2020. Free text survey responses and interview data were subjected to reflexive thematic analyses. Four themes were generated: the overall experience of the service; interactions within the service; treatment and interventions; and outcomes due to the service. Most participants wanted further follow-up and more extensive integration with other services. Most participants described their overall experience positively, especially the available time to address their full range of concerns, but opportunities to integrate the service more fully and to extend follow-up remain.
RESUMO
BACKGROUND: Integrated care may improve outcomes for older people living with frailty. We aimed to assess the effectiveness of a new, anticipatory, multidisciplinary care service in improving the wellbeing and quality of life (QoL) of older people living with severe frailty. METHODS: A community-based non-randomised controlled study. Participants (≥65 years, electronic Frailty Index ≥0.36) received either the new integrated care service plus usual care, or usual care alone. Data collection was at three time points: baseline, 2-4 weeks, and 10-14 weeks. The primary outcome was patient wellbeing (symptoms and other concerns) at 2-4 weeks, measured using the Integrated Palliative care Outcome Scale (IPOS); the secondary outcome was QoL, measured using EQ-5D-5L. To test duration of effect and safety, wellbeing and QoL were also measured at 10-14 weeks. Descriptive statistics were used to characterise and compare intervention and control groups (eligible but had not accessed the new service), with t-test, Chi-Square, or Mann-Whitney U tests (as appropriate) to test differences at each time point. Generalised linear modelling, with propensity score matching, was used for further group comparisons. Data were analysed using STATA v17. RESULTS: 199 intervention and 54 control participants were recruited. At baseline, intervention and control groups were similar in age, gender, ethnicity, living status, and body mass index, but not functional status or area deprivation score. At 2-4 weeks, wellbeing had improved in the intervention group but worsened in the control (median IPOS -5 versus 2, p<0.001). QoL improved in the intervention group but was unchanged in the control (median EQ-5D-5L 0.12, versus 0.00, p<0.001). After adjusting for age, gender, and living status, the intervention group had an average total IPOS score reduction at 2-4 weeks of 6.34 (95% CI: -9.01: -4.26, p<0.05); this improvement was sustained, with an average total IPOS score reduction at 10-14 weeks of 6.36 (95% CI: -8.91:-3.80, p<0.05). After propensity score matching based on functional status/area deprivation, modelling showed similar results, with a reduction in IPOS score at 2-4 weeks in the intervention group of 7.88 (95% CI: -12.80: -2.96, p<0.001). CONCLUSIONS: Our findings suggest that the new, anticipatory, multidisciplinary care service may have improved the overall wellbeing and quality of life of older people living with frailty at 2-4 weeks and the improvement in wellbeing was sustained at three months. ETHICS APPROVAL: NHS Research Ethics Committee 18/YH/0470 and IRAS-250981. TRIAL REGISTRATION: The trial was retrospectively registered at the International Standard Randomised Controlled Trial Number (ISRCTN) registry (registration date: 01/08/2022, registration number: ISRCTN10613839).
