Evaluation of Negation and Uncertainty Detection and its Impact on Precision and Recall in Search

Radiology reports contain information that can be mined using a search engine for teaching, research, and quality assurance purposes. Current search engines look for exact matches to the search term, but they do not differentiate between reports in which the search term appears in a positive context (i.e., being present) from those in which the search term appears in the context of negation and uncertainty. We describe RadReportMiner, a context-aware search engine, and compare its retrieval performance with a generic search engine, Google Desktop. We created a corpus of 464 radiology reports which described at least one of five findings (appendicitis, hydronephrosis, fracture, optic neuritis, and pneumonia). Each report was classified by a radiologist as positive (finding described to be present) or negative (finding described to be absent or uncertain). The same reports were then classified by RadReportMiner and Google Desktop. RadReportMiner achieved a higher precision (81%), compared with Google Desktop (27%; p < 0.0001). RadReportMiner had a lower recall (72%) compared with Google Desktop (87%; p = 0.006). We conclude that adding negation and uncertainty identification to a word-based radiology report search engine improves the precision of search results over a search engine that does not take this information into account. Our approach may be useful to adopt into current report retrieval systems to help radiologists to more accurately search for radiology reports

Health care providers' attitudes towards termination of pregnancy: A qualitative study in South Africa

<p>Abstract</p> <p>Background</p> <p>Despite changes to the abortion legislation in South Africa in 1996, barriers to women accessing abortion services still exist including provider opposition to abortions and a shortage of trained and willing abortion care providers. The dearth of abortion providers undermines the availability of safe, legal abortion, and has serious implications for women's access to abortion services and health service planning.</p> <p>In South Africa, little is known about the personal and professional attitudes of individuals who are currently working in abortion service provision. Exploring the factors which determine health care providers' involvement or disengagement in abortion services may facilitate improvement in the planning and provision of future services.</p> <p>Methods</p> <p>Qualitative research methods were used to collect data. Thirty four in-depth interviews and one focus group discussion were conducted during 2006 and 2007 with health care providers who were involved in a range of abortion provision in the Western Cape Province, South Africa. Data were analysed using a thematic analysis approach.</p> <p>Results</p> <p>Complex patterns of service delivery were prevalent throughout many of the health care facilities, and fragmented levels of service provision operated in order to accommodate health care providers' willingness to be involved in different aspects of abortion provision. Related to this was the need expressed by many providers for dedicated, stand-alone abortion clinics thereby creating a more supportive environment for both clients and providers. Almost all providers were concerned about the numerous difficulties women faced in seeking an abortion and their general quality of care. An overriding concern was poor pre and post abortion counselling including contraceptive counselling and provision.</p> <p>Conclusion</p> <p>This is the first known qualitative study undertaken in South Africa exploring providers' attitudes towards abortion and adds to the body of information addressing the barriers to safe abortion services. In order to sustain a pool of abortion providers, programmes which both attract prospective abortion providers, and retain existing providers, needs to be developed and financial compensation for abortion care providers needs to be considered.</p

Normalizing acronyms and abbreviations to aid patient understanding of clinical texts: ShARe/CLEF eHealth Challenge 2013, Task 2

Background: The ShARe/CLEF eHealth challenge lab aims to stimulate development of natural language processing and information retrieval technologies to aid patients in understanding their clinical reports. In clinical text, acronyms and abbreviations, also referenced as short forms, can be difficult for patients to understand. For one of three shared tasks in 2013 (Task 2), we generated a reference standard of clinical short forms normalized to the Unified Medical Language System. This reference standard can be used to improve patient understanding by linking to web sources with lay descriptions of annotated short forms or by substituting short forms with a more simplified, lay term. Methods: In this study, we evaluate 1) accuracy of participating systems’ normalizing short forms compared to a majority sense baseline approach, 2) performance of participants’ systems for short forms with variable majority sense distributions, and 3) report the accuracy of participating systems’ normalizing shared normalized concepts between the test set and the Consumer Health Vocabulary, a vocabulary of lay medical terms. Results: The best systems submitted by the five participating teams performed with accuracies ranging from 43 to 72 %. A majority sense baseline approach achieved the second best performance. The performance of participating systems for normalizing short forms with two or more senses with low ambiguity (majority sense greater than 80 %) ranged from 52 to 78 % accuracy, with two or more senses with moderate ambiguity (majority sense between 50 and 80 %) ranged from 23 to 57 % accuracy, and with two or more senses with high ambiguity (majority sense less than 50 %) ranged from 2 to 45 % accuracy. With respect to the ShARe test set, 69 % of short form annotations contained common concept unique identifiers with the Consumer Health Vocabulary. For these 2594 possible annotations, the performance of participating systems ranged from 50 to 75 % accuracy. Conclusion: Short form normalization continues to be a challenging problem. Short form normalization systems perform with moderate to reasonable accuracies. The Consumer Health Vocabulary could enrich its knowledge base with missed concept unique identifiers from the ShARe test set to further support patient understanding of unfamiliar medical terms.</p

Economic factors and suicide rates: associations over time in four countries

The original publication is available at www.springerlink.co

Reductions in abortion-related mortality following policy reform: evidence from Romania, South Africa and Bangladesh

Unsafe abortion is a significant contributor to worldwide maternal mortality; however, abortion law and policy liberalization could lead to drops in unsafe abortion and related deaths. This review provides an analysis of changes in abortion mortality in three countries where significant policy reform and related service delivery occurred. Drawing on peer-reviewed literature, population data and grey literature on programs and policies, this paper demonstrates the policy and program changes that led to declines in abortion-related mortality in Romania, South Africa and Bangladesh. In all three countries, abortion policy liberalization was followed by implementation of safe abortion services and other reproductive health interventions. South Africa and Bangladesh trained mid-level providers to offer safe abortion and menstrual regulation services, respectively, Romania improved contraceptive policies and services, and Bangladesh made advances in emergency obstetric care and family planning. The findings point to the importance of multi-faceted and complementary reproductive health reforms in successful implementation of abortion policy reform

Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

Search for the neutral Higgs bosons of the minimal supersymmetric standard model in pp collisions at root s=7 TeV with the ATLAS detector

A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb-1 to 4.8 fb-1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters mA and tan β in the mhmax scenario for mA in the range of 90GeV to 500 GeV. Copyright CERN

In Their Own Words: Assessment of Satisfaction with Residential Location among Migrants in Nairobi Slums

Using qualitative data collected from a sample of rural-urban migrants over the age of 15 in two Nairobi slums interviewed in 2008, this paper discusses the migrants’ extent of satisfaction with their residential location and decision to migrate. The study sheds light on why people continue to migrate to, and stay in, the rapidly growing slum settlements despite the high levels of poverty and poor health conditions in these areas. Tenure status is related to satisfaction for all ages. Environmental factors were frequently mentioned as a source of dissatisfaction. Life cycle and ‘age-cohort effects’ may also affect satisfaction for different age groups in terms of who is satisfied as well as the issues that are considered for satisfaction. High levels of dissatisfaction with slum life may be responsible for high out-migration in slum areas, although it does not mean that those who remain do so because they are satisfied. At the same time, challenges associated with slum life do not automatically signify dissatisfaction. Perceived success, as well as conditions in the area of origin can be used to explain and understand satisfaction/dissatisfaction with slum life. Satisfaction with migration and residential location may be related not only to the destination place, but also to events in the area of origin