Increasing frailty is associated with higher prevalence and reduced recognition of delirium in older hospitalised inpatients: results of a multi-centre study

Purpose: Delirium is a neuropsychiatric disorder delineated by an acute change in cognition, attention, and consciousness. It is common, particularly in older adults, but poorly recognised. Frailty is the accumulation of deficits conferring an increased risk of adverse outcomes. We set out to determine how severity of frailty, as measured using the CFS, affected delirium rates, and recognition in hospitalised older people in the United Kingdom. Methods: Adults over 65 years were included in an observational multi-centre audit across UK hospitals, two prospective rounds, and one retrospective note review. Clinical Frailty Scale (CFS), delirium status, and 30-day outcomes were recorded. Results: The overall prevalence of delirium was 16.3% (483). Patients with delirium were more frail than patients without delirium (median CFS 6 vs 4). The risk of delirium was greater with increasing frailty [OR 2.9 (1.8–4.6) in CFS 4 vs 1–3; OR 12.4 (6.2–24.5) in CFS 8 vs 1–3]. Higher CFS was associated with reduced recognition of delirium (OR of 0.7 (0.3–1.9) in CFS 4 compared to 0.2 (0.1–0.7) in CFS 8). These risks were both independent of age and dementia. Conclusion: We have demonstrated an incremental increase in risk of delirium with increasing frailty. This has important clinical implications, suggesting that frailty may provide a more nuanced measure of vulnerability to delirium and poor outcomes. However, the most frail patients are least likely to have their delirium diagnosed and there is a significant lack of research into the underlying pathophysiology of both of these common geriatric syndromes

[In Press] Fire, drought and flooding rains : the effect of climatic extremes on bird species' responses to time since fire

Aim: Climatic extremes and fire affect ecosystems across the globe, yet our understanding of how species are influenced by the interaction of these broadscale ecological drivers is poorly understood. Using a ten-year dataset, we tested how extreme drought and rainfall interacted with time since fire (TSF) to shape bird species’ distributions. Location: Semi-arid mallee woodlands of south-eastern Australia. Methods: We quantified the effects of climatic extremes on bird species’ occurrence, species richness and incidence at 180 sites across three climatic periods—an El Niñoassociated drought (the “Big Dry”), immediately after La Niña drought-breaking rainfall (“Big Wet”) and three years following the La Niña event (“Post-Big Wet”). We then compared species’ responses with TSF across the three climatic periods using a chronosequence of sites from 1 to 117 years post-fire. Results: La Niña rainfall had sustained impacts on species’ occurrence. Over half of species increased significantly during the Big Wet. Despite three intervening years of below-average rainfall, three quarters of these species remained comparably high, Post-Big Wet. By contrast, less than half of threatened and declining species benefited from high rainfall. Responses of species to TSF were found to differ contingent on climatic conditions: almost twice as many species responded to TSF during the Big Wet and almost three times as many Post-Big Wet, compared with the Big Dry. Across climatic periods, a majority of species showed preference for mid to older post-fire vegetation. Main conclusions: Variation in responses to TSF is likely due to the effect of climatic variation on resources. We suggest that, at sites of different post-fire age, interactions between TSF and climate may differentially influence both the availability and longevity of resources. Given climatic extremes are predicted to become increasingly severe with climate change, accounting for their influence on fauna–fire dynamics will require careful management of fire

Species_data_Triodia&ChenopodMallee

Two data files, one for species recorded in Triodia Mallee and the other for species recorded in Chenopod Mallee. The data is the relative occurrence or abundance of each species by vegetation stage for the three alternate models of vegetation succession (3-stage, 4-stage and 6/7-stage). Species are listed by data type; presence-absence (PA), presence-only (PO) or expert estimates (EE). Some species are present in more than one data type

Data from: Assessing the sensitivity of biodiversity indices used to inform fire management

Biodiversity indices are widely used to summarise changes in the distribution and abundance of multiple species and measure progress towards management targets. However, the sensitivity of biodiversity indices to the data, landscape classification and conservation values underpinning them are rarely interrogated. There are limited studies to help scientists and land managers use biodiversity indices in the presence of fire and vegetation succession. The geometric mean of species’ relative abundance or occurrence (G) is a biodiversity index that can be used to determine the mix of post-fire vegetation that maximizes biodiversity. We explored the sensitivity of G to i) type of biodiversity data, ii) representation of ecosystem states, iii) expression of conservation values and iv) uncertainty in species’ response to landscape structure. Our case study is an area of fire-prone woodland in southern Australia where G is used in fire management planning. We analysed three data sets to determine the fire responses of 170 bird, mammal and reptile species. G and fire management targets were sensitive to the species included in the analysis. The optimal mix of vegetation successional states for threatened birds was more narrowly defined than the optimal mix for all species combined. G was less sensitive to successional classification (i.e. number of states); although classifications of increasing complexity provided additional insights into desirable levels of heterogeneity. Weighting species by conservation status or endemism influenced the mix of vegetation states that maximized biodiversity. When a higher value was placed on threatened species the importance of late successional vegetation was emphasized. Representing variation in individual species’ response to vegetation structure made it clearer when a decrease in G was likely to reflect a significant reduction in species occurrences. Synthesis and applications. Data, models and conservation values can be combined using biodiversity indices to make robust environmental decisions. Combining different types of biodiversity data using composite indices, such as the geometric mean, can improve the coverage and relevance of biodiversity indices. We recommend that evaluation of biodiversity indices for fire management verify how index assumptions align with management objectives, consider the relative merits of different types of biodiversity data, test sensitivity of ecosystem state definitions and incorporate conservation values through species weightings