A corpus-based approach for automated LOINC mapping

Objective To determine whether the knowledge contained in a rich corpus of local terms mapped to LOINC (Logical Observation Identifiers Names and Codes) could be leveraged to help map local terms from other institutions. Methods We developed two models to test our hypothesis. The first based on supervised machine learning was created using Apache's OpenNLP Maxent and the second based on information retrieval was created using Apache's Lucene. The models were validated by a random subsampling method that was repeated 20 times and that used 80/20 splits for training and testing, respectively. We also evaluated the performance of these models on all laboratory terms from three test institutions. Results For the 20 iterations used for validation of our 80/20 splits Maxent and Lucene ranked the correct LOINC code first for between 70.5% and 71.4% and between 63.7% and 65.0% of local terms, respectively. For all laboratory terms from the three test institutions Maxent ranked the correct LOINC code first for between 73.5% and 84.6% (mean 78.9%) of local terms, whereas Lucene's performance was between 66.5% and 76.6% (mean 71.9%). Using a cut-off score of 0.46 Maxent always ranked the correct LOINC code first for over 57% of local terms. Conclusions This study showed that a rich corpus of local terms mapped to LOINC contains collective knowledge that can help map terms from other institutions. Using freely available software tools, we developed a data-driven automated approach that operates on term descriptions from existing mappings in the corpus. Accurate and efficient automated mapping methods can help to accelerate adoption of vocabulary standards and promote widespread health information exchange

Aligning an interface terminology to the Logical Observation Identifiers Names and Codes (LOINC((R)))

OBJECTIVE: Our study consists in aligning the interface terminology of the Bordeaux university hospital (TLAB) to the Logical Observation Identifiers Names and Codes (LOINC). The objective was to facilitate the shared and integrated use of biological results with other health information systems. MATERIALS AND METHODS: We used an innovative approach based on a decomposition and re-composition of LOINC concepts according to the transversal relations that may be described between LOINC concepts and their definitional attributes. TLAB entities were first anchored to LOINC attributes and then aligned to LOINC concepts through the appropriate combination of definitional attributes. Finally, using laboratory results of the Bordeaux data-warehouse, an instance-based filtering process has been applied. RESULTS: We found a small overlap between the tokens constituting the labels of TLAB and LOINC. However, the TLAB entities have been easily aligned to LOINC attributes. Thus, 99.8% of TLAB entities have been related to a LOINC analyte and 61.0% to a LOINC system. A total of 55.4% of used TLAB entities in the hospital data-warehouse have been mapped to LOINC concepts. We performed a manual evaluation of all 1-1 mappings between TLAB entities and LOINC concepts and obtained a precision of 0.59. CONCLUSION: We aligned TLAB and LOINC with reasonable performances, given the poor quality of TLAB labels. In terms of interoperability, the alignment of interface terminologies with LOINC could be improved through a more formal LOINC structure. This would allow queries on LOINC attributes rather than on LOINC concepts only

A comparative assessment of the clean development mechanism and Alberta's carbon offset system

This thesis is an assessment of Alberta’s Carbon Offset System (ACOS) using the Kyoto Protocol’s Clean Development Mechanism (CDM) as a comparator. ACOS is a hybrid policy, having features of both command-and-control and market based instruments. The objective of implementing ACOS within Alberta’s overall greenhouse gas (GHG) emissions mitigation strategy is to provide a cost-effective alternative for regulated facilities to meet their emissions reduction obligations. Offsets generated pursuant to the ACOS are permitted as equivalent alternatives to actual emission reductions under the Specified Gas Emitters Regulation (SGER). The integrity of the emissions intensity limits within the SGER is dependent on the ability of ACOS to generate real, permanent, additional and verifiable offsets that can be substituted for actual emission reductions without any net loss to the environment. The aim of this thesis is to draw lessons from fifteen years of CDM’s “learning by doing” experience and to make recommendations for the reform of the ACOS. This thesis highlights the urgent need for cross-disciplinary and empirical research on the workings of the ACOS; it also highlights the fact that cost-effectiveness is an illusion and the concept of neutrality upon which carbon offsetting is premised needs to be reconsidered as the process of commodification does not result in offsets that are perfectly substitutable with actual emissions reductions. Proposals for reforming the ACOS include imposing limits on the use of offsets, recommending market oversight for offset trades that are currently traded over-the-counter, narrowing the scope of ACOS to a single gas system and enhancing the verification process by eliminating conflict of interest dilemmas

Posthospital follow-up visits and 30-day readmission rates in chronic obstructive pulmonary disease

Salman S Fidahussein,1 Ivana T Croghan,2 Stephen S Cha,3 David L Klocke4 1Department of Pulmonary and Critical Care Medicine, Norwalk Hospital, Norwalk, CT, 2Department of Medicine Clinical Research Office, 3Department of Health Sciences Research, 4Division of Hospital Internal Medicine, Department of Medicine, Mayo Clinic, Rochester, MN, USA Purpose: To examine the effect of a follow-up visit with a primary care physician and/or pulmonologist within the first 30 days of hospital discharge on readmissions, emergency department (ED) visits, and mortality. Patients and methods: This was a retrospective cohort study of 7,102 unique patients discharged from a Mayo Clinic hospital in Rochester, MN, and residing in Olmsted County, MN, with any mention of chronic obstructive pulmonary disease (COPD) from January 1, 2004 through November 30, 2011. The study included 839 patients who met study-entry criteria. Cox proportional hazards regression was performed to determine the risk of hospital readmission, ED visits, and death of patients, with or without a follow-up visit during the first 30 days postdischarge. Results: Our results showed 839 unique patients experienced 1,422 discharges with a primary diagnosis of COPD. Of the 1,422 discharges, 973 (68.4%) had a follow-up visit within 30 days. In a multivariate Cox proportional hazard-ratio (HR) model analysis, occurrence of a follow-up visit did not have a significant effect on the risk of the combined outcome of 30-day readmission and ED visit (HR 0.947, confidence interval 0.763–1.177; P=0.63). However, a postdischarge follow-up visit had a significant effect on 30-day mortality (HR 0.279, confidence interval 0.149–0.523; P<0.001). Conclusion: Postdischarge follow-up visits after hospitalization for COPD did not significantly reduce the risk of 30-day readmission or ED visit. However, patients who received postdischarge follow-up visits had significantly reduced 30-day mortality. Keywords: care transitions, COPD, discharge planning, outpatient follow-up, risk factor

Antifungal Activity of Crude Extracts of Gladiolus Dalenii van Geel (Iridaceae)

Bulb extracts of Gladiolus dalenii reportedly used in the treatment of fungal infections in HIV/AIDS patients in the Lake Victoria region were tested for antifungal activity using the disc diffusion assay technique. Commercially used antifungal drugs, Ketaconazole and Griseofulvin (Cosmos Pharmaceuticals) were used as standards. Dichloromethane (CH2CL2)/Methanol (MeOH) in the ratio 1:1. Soluble extracts showed antifungal activity against Aspergillus niger. Direct bioautography on silica gel Thin Layer Chromatography (TLC) and appropriate spraying agents were used to identify the active component in the extract. The activities of both the extracts were higher than that of Griseofulvin. CH2CL2 soluble extract in addition showed ability to delay sporulation in A.niger. The active group of compounds in the extracts was identified as alkaloids, which offer immense potential for development of new and valuable pharmaceutical products