Conference Papers
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/6561
This collection contains abstracts of conference papers, presented at local and international conferences by the staff of the Faculty of Medicine
Browse
7 results
Search Results
Item Evidence-based and epidemiological interpretation of the diagnosis of SARS-COV-2(Sri Lanka Medical Association, 2021) Abeysena, C.; Gamage, A.INTRODUCTION AND OBJECTIVES: Diagnostic tests are never perfect; hence cannot definitely tell whether the disease is present or absent which leads to inaccurate decisions by healthcare workers. The key metrics in interpreting the accuracy are sensitivity and specificity and the test performance measures of positive-predictive-value(PPV) and negative-predictive-value (NPV). Positive and negative predictive values of diagnostic tests vary depending upon the pre-test probability. This paper aims to compile the evidence generated and facilitate the epidemiological interpretation of diagnostic laboratory testing available for COVID-19 pandemic. METHODS: We searched systematic reviews published, especially Cochrane reviews and evidence summaries. Diagnostic accuracy studies were searched when there were no published systematic reviews. PPV, NPV and its 95% confidence intervals (CI) were calculated for the reported sensitivities and specificities and assumed pre-test probability levels. RESULTS: At a low pre-test probability level, PPV is 50%(95%CI: 28%-72%) when we assume 56% sensitivity of the antigen test. If the sensitivity is low, PPV will be low and vice versa; however, the NPV is 69.3% (95%CI: 67%-71%). Considering RT-PCR test PPV is 28.6%(95%CI: 13%-52% at a low pre-test probability level) when we assume 40% sensitivity. Assuming RT-PCR sensitivity is 95%, PPV is 47.4% (95%CI: 32%-63%), NPV is 62.3%(95%CI: 60.6% to 63.9%). Further, assuming that the sensitivity of the RT-PCR is 95%, NPV is 95.2%(95%CI: 93.1% to 96.7%). CONCLUSION: In low resource settings symptoms, signs, basic laboratory and other investigations can be used to screen COVID-19 patients and interpretation of the results of the antigen and RT-PCR test for better diagnosis.Item 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.Item Energy expenditure and pregnancy outcome(Sri Lanka College of Obstetricians and Gynaecologists, 2005) Abeysena, C.; Jayawardana, P.; Seneviratne, R.OBJECTIVE: To determine the effect of energy expenditure on pregnancy outcome. Methodology: A prospective cohort study was carried out at Ragama and Ja-ela MOH areas. Eight hundred and seventy five pregnant mothers were recruited at 16 weeks of gestation (POA). Daily energy expenditure was assessed based on the activities indicated by the pregnant mothers in the Activity Record1 on two occasions during 20 (371 subjects) and 32weeks of POA (271 subjects) at home by housewives and both at home and at work by working mothers. On each occasion activities related to 3 different days were recorded. Average energy expenditure was calculated and >2550 kcal/day was considered as the cut off. Information on potential confounding factors was gathered on average at 12th, 28s11 and 36 POA. Pregnancy outcome was assessed in terms of maternal complications (MC) such as pre-eclampsia, ante-partum haemorrhage and gestational diabetes, pre-term birth , low birth weight (LEW), small for gestational age <10dl (SGA<1O) and <5th (SGA<5) centiles. Logistic regression analysis was applied and the results are expressed as odds ratios (OR) and 95% confidence intervals (95%CI). Results: Univarite analysis revealed that >2550 kcal/day energy expenditure during 20 weeks of POA was significantly associated with subsequent development of MC (OR6.86, 95% CP=2.38-19.76) and with MC (OR=1 1.03, 95%CFI.36-89.24), LBW (OR=O.05, 95% CI-O.006-0.36) and SGA<5 (OR=O.29, 95% CIO.10-0.87) during 32" xveek of POA. On multivariate analysis subsequent development of MC (OR=6.305 95% CI 21.94} and SGA<5 (OR=0.29, 95% CI = 0.09-O.96), remained significantly associated with high energy expenditure during 20 ' week of POA and 32"d week of POA respectively. CONCLUSION: High energy expenditure was a risk factor for maternal complications and a protective factor against the birth of a small for gestational age infant.Item Risk factors for delivering a small for gestational age infant(Sri Lanka College of Obstetricians and Gynaecologists, 2004) Abeysena, C.; Jayawardana, P.L.; Seneviratne, S.R.A.OBJECTIVE: To determine the risk factors for delivering a small for gestatJonal age (SGA) infant. METHODOLOGY: A prospective study was carried out at two MOH areas in the Gampaha district, during the period of May 2001 to April 2002. Eight hundred and twenty pregnant mothers were recruited at £16 weeks of gestation and followed up until partus. Demographic, socloeconomic and obstetric data of the mothers were gathered at the time of recruitment. Trimester specific exposure statuses along with potential confounding factors were gathered on average at the 12 , 28 and 36 weeks of gestation. Physical activities were assessed by asking the duration of specific postures adopted per day by the mothers during each trimester at home for house wives and both at home and during working hours for those who were engaged in paid employment. Shift work and work related physical and chemical exposures were also assessed. Psychosocial stress was ascertained using the Modified Life Events Inventory and the General Health QuestionnaireJJO. Ultrasound scan was performed to determine the gestationai age based on foetal biparietal diameter. SGA was assessed using customized growth centile charts developed by Gardosi et al. Univariate and multivariate logistic regression analysis (sample size=504) were applied and the results are expressed in odds ratios (OR) and 95% confidence intervals (95%CI) with the probability levels (P). RESULTS: When cut off for SGA was considered as <10 centile of the customized birth weight centiles, the proportion of SGA was 16.4%. Although the univariate analysis revealed that sleeping for < 8 hours during 2" or 3 or both trimesters (OR=1.645 95% CI= 1.00-2.67; P=0.04) and work related exposures during 2 or 3 or both trimesters (OR=2.42,95% GUI.19-4.93; P=0.01) were significantly associated with SGA, none of these factors became significant on multivariate logistic regression analysis. When the cut off was considered as <5 centile of the customised birth weight centiles, the proportion of SGA was 8.8%. Sleeping <8 hours during 2 or 3 or both trimesters (OR=2.34,95% CI=1.18-4.61; P=0.01), work related exposures during 2" or 3' or both trimesters (OR=2.91, 95% CM.27-6.65; P=0.01) and alcohol consumption during the 3' trimester {OR=4.33, 95% CI=1.11-16.94; P=0.03) had statistically significant association with SGA in the univariate analysis. Multivariate logistic regression also revealed that sleeping for <8 hours during 2" or 3 or both trimesters (OR=2.14, 95% 01=1.06-4.32; P=0.03), and walking for < 2.5 hours per day (OR=2.40> 95% CM.05-5-51; P=0.04) and alcohol consumption during the 3' trimester (OR=8.01,95% CM.31-49.02; P=0.02) were risk factors. CONCLUSIONS: Risk factors for being SGA when SGA is defined as <5 centile of the customised birth weight centiles are, sleeping for <8 hours during 2 or 3 or both trimesters, walking < 2.5 hours per day and alcohol consumption during 3 trimester. It is recommended that the importance of sleeping >8 hours and walking > 2.5 hours per day and avoidance of alcohol be emphasised to pregnant mothers.Item The quality of controlled clinical trial reporting in five leading Sri Lankan medical journals(Sri Lanka Medical Association, 2012) Pathirana, T.I.; Abeysena, C.INTRODUCTION: The Consolidated Standards of Reporting Trials (CONSORT) statement and the Transparent Reporting of Evaluations with Non-randomized Designs (TREND) checklist help improve the quality of reporting of trials. Report quality is often used as a surrogate measure of methodological quality. AIMS: To assess the quality of reporting of clinical trials published in five leading Sri Lankan medical journals METHODS: Five medical journals published between 1982-2011 were hand searched for randomized (RCT) and non-randomized clinical trials (NRCT) conducted in humans. These were evaluated by two independent observers to assess them against a checklist developed based on CONSORT and TREND recommendations. Outcome measures were presence of checklist items in published reports. Results: Twenty two RCT and 16 parallel group NRCT from 160 journals were included. Out of them, Thirty six (94.7%) clearly described the objectives, 13 (34.2%) the periods of recruitment, 7(18.4%) sample size determination, 12(31.6%) the flow of participants through each stage,19 (50%) baseline demographic and clinical characteristics of each group. Twenty one (55.3%) used statistical methods to compare groups for primary outcome, 21(55.3%) effect size, 4 (10.5%) its precision. Twenty (52.6%) interpreted the results in the context of current evidence. Five (13.2%) described the generalizability of the findings. Of the 22 RCT, only one (4.5%) reported sequence generation, 3(13.6%) allocation concealment, 7(31.8%) blinding status of participants or investigators and 2(9.1%) intention to treat analysis. CONCLUSIONS: Reporting of several essential criteria of remain suboptimal. Awareness of the CONSORT and TREND statements may improve matters quality of reporting.Item Physical activity and weight gain during the period from first trimester of pregnancy to six months post partum(Sri Lanka Medical Association, 2013) Perera, M.G.S.N.S.; Abeysena, C.INTRODUCTION AND OBJECTIVES: Weight gain from first trimester of pregnancy to six months post partum, places a woman at risk of developing obesity in later life. Objectives were to determine the association between physical activity and weight gain during the period first trimester of pregnancy to six months post partum, in mothers attending child welfare clinics in Biyagama and Kelaniya Medical Officer of Health areas. METHODS: This was a clinic based descriptive cross sectional study, conducted from August to October 2012. International Physical Activity was used in data collection. Low physical activity was defined as no activity or < total 600 MET-min/week (Metabolic Equivalents of Task) for 5 or more days. Results were expressed as percentages, Odds ratios (OR) and 95% confidence intervals (CI). Multivariate logistic regression was performed to control for confounders. RESULTS: Mdian total Physical Activity was 1,087 MET-minutes per week (inter quartile range IQR 240 - 1836). Low level of physical activity was observed in 38.8% (95% Cl 34 -44%) of mothers. Percentage of mothers who gained weight from first trimester of pregnancy to six month post partum was 67.8% (95% CI 63% -72%). Multivariate logistic regression showed low level of physical activity was significantly associated with weight gain from first trimester to six months post partum OR12.0 (95% CI 6.1-23.8, p=0.001). CONCLUSION: Low level of physical activity was associated with weight gain from first trimester of pregnancy to six months postpartum.Item Knowledge about acute coronary syndrome of patients admitted to National Hospital of Sri Lanka(Sri Lanka Medical Association, 2010) Ariyarathne, A.M.N.; Abeysena, C.; Liyanage, D.L.D.C.OBJECTIVES: To describe knowledge about ACS, secondary prevention of ACS and selected risk factors and sources of knowledge of patients with ACS, admitted to NHSL. METHODS: This was a hospital based descriptive cross sectional study carried out in two settings at NFISL, cardiology unit and medical wards during September to October 2009. A sample consisting of 345 patients were recruited in to the study, who were diagnosed as ACS. Data was collected by using a self administered questionnaire and it was used to collect data about knowledge on ACS, secondary preventive measures, smoking, alcohol and life style change. There were 17.6% (n=61) non respondents for the self administered questionnaire. RESULTS: Knowledge about ACS was good among 32.7% (n=93) study subjects. Good knowledge on smoking, alcohol and lifestyle change was 61.3% (n=174), 53.6% (n=155) and 60.9% (n=173), respectively. Patients treated at cardiology unit had statistically significant good knowledge about ACS, compared to medical wards. Total knowledge score in relation to the age, education level of the study subjects was statistically significant (p<0.05). Many of the patients gathered their knowledge from medical officers who were working at NHSL and TV/Radio and printed media were also good sources of knowledge. CONCLUSIONS: Patients' knowledge about acute coronary syndrome, secondary prevention of acute coronary syndrome and selected risk factors were poor. Medical officers working at NHSL were a good source of knowledge.