40 research outputs found
A Local Search Algorithm for the Min-Sum Submodular Cover Problem
We consider the problem of solving the Min-Sum Submodular Cover problem using
local search. The Min-Sum Submodular Cover problem generalizes the NP-complete
Min-Sum Set Cover problem, replacing the input set cover instance with a
monotone submodular set function. A simple greedy algorithm achieves an
approximation factor of 4, which is tight unless P=NP [Streeter and Golovin,
NeurIPS, 2008]. We complement the greedy algorithm with analysis of a local
search algorithm. Building on work of Munagala et al. [ICDT, 2005], we show
that, using simple initialization, a straightforward local search algorithm
achieves a -approximate solution in time
, provided that the monotone submodular set function is
also second-order supermodular. Second-order supermodularity has been shown to
hold for a number of submodular functions of practical interest, including
functions associated with set cover, matching, and facility location. We
present experiments on two special cases of Min-Sum Submodular Cover and find
that the local search algorithm can outperform the greedy algorithm on small
data sets
Mass media and communication interventions to increase HIV testing among gay and other men who have sex with Men:Social marketing and visual design component analysis
Mass media and communication interventions can play a role in increasing HIV testing among gay, bisexual and other men who have sex with men (GBMSM). Despite the key role of social marketing principles and visual design within intervention development of this type, evidence is limited regarding interventions’ social marketing mix or visual design. As part of a systematic review, intervention content was assessed using social marketing theory and social semiotics. Data were extracted on the nature of the intervention, mode of delivery, use of imagery, content and tone and the eight key characteristics of social marketing. Data were synthesised narratively. Across the 19 included studies, reference to social marketing principles was often superficial. Common design features were identified across the interventions, regardless of effectiveness, including: the use of actors inferred to be GBMSM; use of ‘naked’ and sexually explicit imagery; and the use of text framed as statements or instructions. Our results suggest that effective interventions tended to use multiple modes of delivery, indicating high social marketing complexity. However, this is only part of intervention development, and social marketing principles are key to driving the development process. We identified consistent aspects of intervention design, but were unable to determine whether this is based on evidence of effectiveness or a lack of originality in intervention design. An openness to novel ideas in design and delivery is key to ensuring that evidence-informed interventions are effective for target populations
Longitudinal Trends in All Healthcare-Associated Infections through Comprehensive Hospital-wide Surveillance and Infection Control Measures over the Past 12 Years: Substantial Burden of Healthcare-Associated Infections Outside of Intensive Care Units and “Other” Types of Infection
OBJECTIVE Targeted surveillance has focused on device-associated infections and surgical site infections (SSIs) and is often limited to healthcare-associated infections (HAIs) in high-risk areas. Longitudinal trends in all HAIs, including other types of HAIs, and HAIs outside of intensive care units (ICUs) remain unclear. We examined the incidences of all HAIs using comprehensive hospital-wide surveillance over a 12-year period (2001–2012). METHODS This retrospective observational study was conducted at the University of North Carolina (UNC) Hospitals, a tertiary care academic facility. All HAIs, including 5 major infections with 14 specific infection sites as defined using CDC criteria, were ascertained through comprehensive hospital-wide surveillance. Generalized linear models were used to examine the incidence rate difference by infection type over time. RESULTS A total of 16,579 HAIs included 6,397 cases in ICUs and 10,182 cases outside ICUs. The incidence of overall HAIs decreased significantly hospital-wide (−3.4 infections per 1,000 patient days), in ICUs (−8.4 infections per 1,000 patient days), and in non-ICU settings (−1.9 infections per 1,000 patient days). The incidences of bloodstream infection, urinary tract infection, and pneumonia in hospital-wide settings decreased significantly, but the incidences of SSI and lower respiratory tract infection remained unchanged. The incidence of Clostridium difficile infection (CDI) increased remarkably. The outcomes were estimated to include 700 overall HAIs prevented, 40 lives saved, and cost savings in excess of $10 million. CONCLUSIONS We demonstrated success in reducing overall HAIs over a 12-year period. Our data underscore the necessity for surveillance and infection prevention interventions outside of the ICUs, for non–device-associated HAIs, and for CDI. Infect Control Hosp Epidemiol 2015;36(10):1139–114
The effectiveness of social marketing interventions to improve HIV testing among gay, bisexual and other men who have sex with men: A systematic review
HIV testing is central to biomedical HIV prevention, but testing among men who have sex with men remains suboptimal. We evaluated effectiveness of mass media and communication interventions to increase HIV testing and explored patterns between study type, internal validity and intervention effectiveness for the first time. Five databases were searched for articles published between 2009 and 2016 using standard MeSH terms. Eligible studies were quality appraised using standard checklists for risk of bias. Data were extracted and synthesised narratively. Nineteen studies met inclusion criteria; 11 were cross-sectional/non-comparative studies, four were pre/post or interrupted time series, three were randomised controlled trials (RCTs) and one was a case study. Risk of bias was high. Five cross-sectional (two graded as high internal validity, one medium and two low) and one RCT (medium validity) reported increased HIV testing. Further work is required to develop and evaluate interventions to increase frequency and maintenance of HIV testing
Invasive cutaneous rhizopus infections in an immunocompromised patient population associated with hospital laundry carts
Mucormycosis is an invasive fungal infection with high
morbidity and mortality that most commonly occurs in
immunocompromised hosts.1–5 Cutaneous mucormycosis is
rare and can be acquired through direct contact of the fungi
with non-intact skin or mucous membranes.3,4,7–9 Outbreaks
of mucormycosis associated with contaminated adhesive
bandages, ostomy supplies, wooden tongue depressors, and
linen have been published.1,6–9 This is a report of a cluster of
cutaneous mucormycosis with Rhizopus that occurred in 4
immunocompromised inpatients housed primarily in the
same intensive care unit (ICU) prior to infection
Perceptions of Cancer Clinical Research Among African American Men in North Carolina
The problem of cancer health disparities is substantial. Clinical trials are widely advocated as a means of reducing disparities and bringing state-of-the-art care to the broader community, where most cancer care is delivered. This study sought to develop a better understanding of why disproportionately few African American men enroll in clinical trials given their substantial cancer burden
Strategies Utilized to Prevent and Control SARS-CoV-2 Transmission in Two Congregate, Psychiatric Healthcare Settings During the Pandemic
BACKGROUND: The COVID-19 pandemic has had a substantial effect on the delivery of psychiatric healthcare. Inpatient psychiatric healthcare facilities have experienced outbreaks of COVID-19, making these areas particularly vulnerable. METHODS: Our facility used a multidisciplinary approach to implement enhanced infection prevention and control (IPC) interventions in our psychiatric healthcare areas. RESULTS: In a sixteen-month period during the COVID-19 pandemic, our two facilities provided >29,000 patient days of care to 1,807 patients and identified only forty-seven COVID-19 positive psychiatric health inpatients (47/1,807, or 2.6%). We identified the majority of these cases by testing all patients at admission, preventing subsequent outbreaks. Twenty-one psychiatric healthcare personnel were identified as COVID+ during the same period, with 90% linked to an exposure other than a known positive case at work. DISCUSSION: The IPC interventions we implemented provided multiple layers of safety for our patients and our staff. Ultimately, this resulted in low SARS-CoV-2 infection rates within our facilities. CONCLUSIONS: Psychiatric healthcare facilities are uniquely vulnerable to COVID-19 outbreaks because they are congregate units that promote therapeutic interactions in shared spaces. IPC interventions used in acute medical care settings can also work effectively in psychiatric healthcare, but often require modifications to ensure staff and patient safety
Building a Personal Protective Equipment Monitor Team as Part of a Comprehensive COVID-19 Prevention Strategy
We instituted Personal Protective Equipment (PPE) Monitors as part of our care of COVID-19 patients in high-risk zones. PPE Monitors aided healthcare personnel (HCP) in donning and doffing, which contributed to nearly zero transmission of COVID-19 to HCP, despite their care of over 1400 COVID-19 patients
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy