Socio-demographic and clinical characteristics of re-presentation to an Australian inner-city emergency department: implications for service delivery

BACKGROUND: People who have complex health care needs frequently access emergency departments for treatment of acute illness and injury. In particular, evidence suggests that those who are homeless, or suffer mental illness, or have a history of substance misuse, are often repeat users of emergency departments. The aim of this study was to describe the socio-demographic and clinical characteristics of emergency department re-presentations. Re-presentation was defined as a return visit to the same emergency department within 28 days of discharge from hospital. METHODS: A retrospective cohort study was conducted of emergency department presentations occurring over a 24-month period to an Australian inner-city hospital. Characteristics were examined for their influence on the binary outcome of re-presentation within 28 days of discharge using logistic regression with the variable patient fitted as a random effect. RESULTS: From 64,147 presentations to the emergency department the re-presentation rate was 18.0% (n = 11,559) of visits and 14.4% (5,894/40,942) of all patients. Median time to re-presentation was 6 days, with more than half occurring within one week of discharge (60.8%; n = 6,873), and more than three-quarters within two weeks (80.9%; n = 9,151). The odds of re-presentation increased three-fold for people who were homeless compared to those living in stable accommodation (adjusted OR 3.09; 95% CI, 2.83 to 3.36). Similarly, the odds of re-presentation were significantly higher for patients receiving a government pension compared to those who did not (adjusted OR 1.73; 95% CI, 1.63 to 1.84), patients who left part-way through treatment compared to those who completed treatment and were discharged home (adjusted OR 1.64; 95% CI, 1.36 to 1.99), and those discharged to a residential-care facility compared to those who were discharged home (adjusted OR 1.46: 95% CI, 1.03 to 2.06). CONCLUSION: Emergency department re-presentation rates cluster around one week after discharge and rapidly decrease thereafter. Housing status and being a recipient of a government pension are the most significant risk factors. Early identification and appropriate referrals for those patients who are at risk of emergency department re-presentation will assist in the development of targeted strategies to improve health service delivery to this vulnerable group

Silver in river and estuarine waters of Texas: Evidence for complexation to macromolecular organic matter

9-14Concentration and phase speciation of Ag in selected Texas rivers and in the Trinity River estuary were measured in order to establish the major factors which control its fate in the aquatic environment from source to sink. Concentrations of Ag in the filter-passing fractions in Texas rivers ranged from <0.01 to 62 ng/L. In the Trinity River estuary (Galveston Bay), they ranged from 0.4 to 6.4 ng/L and showed a non-conservative estuarine mixing behavior. An example is shown in Figure 1. An internal source of both filter-passing ( less than or equal to 0.45 mu m) and colloidal (1kDa similar to 0.45 mu m) Ag was observed in the upper Trinity Bay. Silver, associated with colloidal macromolecular organic matter, which was isolated using cross-flow ultrafiltration techniques, amounted to 15-70% of the filtered ( less than or equal to 0.45 mu m) Ag concentration, decreasing with increasing salinity. Such a trend was similar to that of dissolved and colloidal organic carbon. Estuarine distributions of colloidal Ag were also broadly similar to those of suspended particulate matter. The ratio of colloidal Ag to filter-passing Ag was similar to the ratio of colloidal organic carbon to total dissolved organic carbon (Figure 2), suggesting not only that Ag is complexed by organic macromolecules, likely to sulfhydryl groups, but also that these functional groups were evenly distributed over the different molecular weight fractions. Particulate Ag was found associated mainly with a Fe-Mn oxyhydroxide/sulfide phase. The close relation between Ag and Fe in colloidal and particulate phases (Figures 3 and 4) suggests common surface complexes, probably again sulfhydryl groupshttp://gbic.tamug.edu/request.ht