Conference Papers

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This collection contains abstracts of conference papers, presented at local and international conferences by the staff of the Faculty of Medicine

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    Evidence-based and epidemiological interpretation of the diagnosis of SARS-COV-2
    (College of Community Physicians of Sri Lanka, 2021) Abeysena, C.; Gamage, A.U.
    Introduction: Diagnostic tests are never perfect, leading to inaccurate decisions by healthcare workers. Study aimed to compile the evidence and facilitate the epidemiological interpretation of testing available for the COVID-19. Methods: Published systematic reviews, especially Cochrane reviews and evidence summaries were used. Positive-predictive-values (PPV), negative-predictive-values (NPV), and its 95% confidence intervals (CI) were calculated following application to a hypothetical cohort of 1000 patients, the reported sensitivities and specificities and assumed pre-test probability levels. Results: At a low pre-test probability level, PPV is 63.6%(95%CI: 37.8%-83.5%) when assumed 72%sensitivity of the antigen test among symptomatic patients and 60.0% 95%CI: 33.3%-81.8%) when assumed 58% sensitivity of the antigen test among asymptomatic patients. If the sensitivity is low, PPV will become a low value. PPV is high with a higher pre-test probability level; however, the NPV is 78%(95%CI: 75.5%-80.4%) among symptomatic and 70.3%(95%CI: 68%-72.4%) among asymptomatic patients. PPV is 44.4% (95%CI: 28.6%-61.5% at a low pre-test probability level) when assumed 80% sensitivity for the RT-PCR test. Further, assuming that the sensitivity of 95%, PPV is 47.4% (95%CI: 32%-63%). At a higher pre-test probability level, the NPV is 83.2% (95%CI: 80.6%-85.5%) when assumed 80% sensitivity. Further, the sensitivity of the RT-PCR is 95%, NPV is 95.2%(95%CI: 93.1% to 96.7%). Conclusions: With a low pre-test probability, positive results should be interpreted cautiously and need a second specimen tested for confirmation for both Ag and PCR testing. With higher pre-test probability, the confidence in negative COVID-19 test results is low. Therefore, a combination of symptoms, signs, laboratory investigations can be used with antigen and RT-PCR tests, for diagnosis of COVID-19.
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    Knowledge and practices on selected non communicable diseases among GCE Advanced Level students in state schools, Maharagama
    (College of Community Physicians of Sri Lanka, 2009) Gamage, A.U.; Jayawardana, P.
    OBJECTIVE: To assess the knowledge on selected non communicable diseases (NCDs) and practices related to prevention of selected NCDs among GCE Advanced Level (A/L) students attending government schools in the Maharagama education division. METHODS: A descriptive cross sectional study was conducted among year 13 students (A/L) attending state schools in Maharagama education division. A total of 634 students were selected from 9 schools which had at least one class in a given stream. Stratified sampling was done according to stream of study and the number needed from each stratum was decided according to probability proportionate to size. Cluster sampling was conducted when the number of classes in each stream was more than one. A self administered questionnaire was used to gather information on socio demographic data, practices, knowledge on NCDs and sources of information. Height and weight measurements were recorded. Each practice was analysed separately, either based on the indulgence or on a cut off score. A composite score of >60% was considered as good overall knowledge. RESULTS: Of the 634 respondents 45.3% (n=287) were males. The mean age was 18.4(SD±0.38) years. Knowledge: The proportion with good overall knowledge was 43% (95%CI: 39%-46.9%) [n=272]. Good overall knowledge was significantly higher among non Sinhalese (88%; n=5) and science stream students (65%; n=85) (p< 0.001). Practices: Proportion of students who had a healthy diet was 43% (n=275) and adequate physical activity was 20% (n=129). Three percent (n=18) were current smokers, all of whom were males and 10% (n=61) of males and 2% (n=12) of females were current users of alcohol. Proportion of females was significantly higher in relation to healthy dietary habits (52.2%; n=181 versus 32.8%; n=94 ), non smoking (100%; n=347 versus 93.7%; n=269) and non alcohol consumption (96.5%; n=335 versus 78.7%; n=226) and males in relation to adequate physical activity (27.5%; n=79 versus 14.4%; n=50). Schools (41%; n=233) were the major source of information on NCDs and preferred sources were healthcare workers (34%; n=201) and schools (32%; n=192). CONCLUSION: Proportion of year 13 A/L students with good knowledge and practices was low and recommend awareness raising programs.