The Effect of English Language on Multiple Choice Question Scores of Thai Medical Students.

BACKGROUND: Universities in Thailand are preparing for Thailand's integration into the ASEAN Economic Community (AEC) by increasing the number of tests in English language. English language is not the native language of Thailand Differences in English language proficiency may affect scores among test-takers, even when subject knowledge among test-takers is comparable and may falsely represent the knowledge level of the test-taker. OBJECTIVE: To study the impact of English language multiple choice test questions on test scores of medical students. MATERIAL AND METHOD: The final examination of fourth-year medical students completing internal medicine rotation contains 120 multiple choice questions (MCQ). The languages used on the test are Thai and English at a ratio of 3:1. Individual scores of tests taken in both languages were collected and the effect of English language on MCQ was analyzed Individual MCQ scores were then compared with individual student English language proficiency and student grade point average (GPA). RESULTS: Two hundred ninety five fourth-year medical students were enrolled. The mean percentage of MCQ scores in Thai and English were significantly different (65.0 ± 8.4 and 56.5 ± 12.4, respectively, p < 0.001). The correlation between MCQ scores in Thai and English was fair (Spearman's correlation coefficient = 0.41, p < 0.001). Of 295 students, only 73 (24.7%) students scored higher when being tested in English than in Thai language. Students were classified into six grade categories (A, B+, B, C+, C, and D+), which cumulatively measured total internal medicine rotation performance score plus final examination score. MCQ scores from Thai language examination were more closely correlated with total course grades than were the scores from English language examination (Spearman's correlation coefficient = 0.73 (p < 0.001) and 0.53 (p < 0.001), respectively). The gap difference between MCQ scores in both languages was higher in borderline students than in the excellent student group (11.2 ± 11.2 and 7.1 ± 8.2, respectively, p < 0.001). Overall, average student English proficiency score was very high, at 3.71 ± 0.35 from a total of 4.00. Mean student GPA was 3.40 ± 0.33 from a possible 4.00. English language MCQ examination scores were more highly associated with GPA than with English language proficiency. CONCLUSION: The use of English language multiple choice question test may decrease scores of the fourth-year internal medicine post-rotation final examination, especially those of borderline students.

Impact of GLI-2012 Spirometric References and Lower Limit of Normal on Prevalence of COPD in Older Urban Thai Persons.

BACKGROUND: Previous analysis of survey data from a study in older urban Thai persons reported prevalence of chronic obstructive pulmonary disease (COPD) of 7.11% according to formerly recommended criteria that used fixed ratio (70%) of pre-bronchodilator FEV1/FVC as the cut-off value. In 2012, the Global Lung Initiative (GLI)-2012 equations for spirometric reference were established and the diagnostic criteria for COPD were changed. OBJECTIVE: To reanalyze the data collected during the 2002 respiratory health survey to determine prevalence of COPD in older urban Thai persons according to the new GLI-2012 equations. MATERIAL AND METHOD: Demographic and clinical data of 3,094 subjects aged ≥ 60 years from 124 urban communities were re-analyzed. Prevalence of COPD determined by post-bronchodilator FEV1/FVC and GLI-2012 equations using lower limit of normal by the Lambda-Mu-Sigma method (LMS-LLN) was compared to COPD prevalence findings based on criteria used in previous analysis. RESULTS: Prevalence of COPD in the study population using post-bronchodilator FEV1/FVC and LMS-LLN was 6.50% (95% CI: 5.63-7.3 7), compared with 7.82% (95% CI: 6.87-8.77) when fixed ratio (70%) of FEV1/FVC was used as cut-off. Diagnostic agreement of COPD between LMS-LLN and fixed ratio was high (kappa 0.88, p < 0.0001). However 45/242 (18.6%) subjects diagnosed as COPD by fixed ratio criteria were considered as "over-diagnosed" when LMS-LLN was used as the standard cut-off The same comparison applied to subjects aged 80 years revealed an increased rate of over-diagnosis to 7/22 (31.8%) subjects. Higher agreement was observed (kappa 0.95, p < 0.0001) when comparing between cut-offs for diagnosis of "at least GOLD stage II" COPD. CONCLUSION: Prevalence of COPD in older urban Thai persons was lower when LMS-LLN was substituted for fixed ratio (70%) of FEV1/FVC. Agreement in COPD diagnosis between both criteria was high, but a substantial proportion of subjects may be over-diagnosed

Validity and reliability assessment of the Siriraj Asthma Control Questionnaire.

OBJECTIVE: The present study assessed the validity and reliability of the Siriraj Asthma Control Questionnaire in Asthma Clinic, Siriraj Hospital. MATERIAL AND METHOD: The data of the questionnaire responses and spirometric results from 20 randomized asthmatic patients in the clinic including the record of 3 visits for each subject. The validation was performed by Kruskal-Wallis test comparing the scores with the level of asthma control determined by physicians according to GINA guideline. Internal consistency reliability was analyzed by Cronbach's alpha. RESULTS: Sixty questionnaires from 20 patients with age 29-73 years were analyzed. There were 40 controlled, 7 partly controlled and 13 uncontrolled visits. The scores from 5-items questionnaires and 6-items clinical score were significantly associated with the physician-diagnosed groups (i.e., controlled, partly controlled and uncontrolled groups). Median scores (min, max) were 0 (0, 5), 2 (0, 6), 4 (0, 12) respectively, (5-items, p < 0.001) and 2 (0, 7), 3 (1, 7), 6 (2,15) respectively, (6-items, p < 0.001). Internal consistency reliability of both 5-items questionnaire and 6-items clinical score were within the acceptable range (0.829 and 0.708 respectively). 5-items questionnaire is more associated with the physician diagnosed group and more consistent than 6-items clinical score. Further analysis revealed cutoff point at 2.5 to separate uncontrolled from controlled or partly controlled patient with sensitivity 76.9% and specificity 89.4% and cutoff point at 1.5 to separate uncontrolled or partly controlled from controlled patient with sensitivity 70.0% and specificity 85.0%. CONCLUSION: The validity and reliability of Siriraj Asthma Control Questionnaire is acceptable and might be used in the clinical practice and research in Thai asthmatic patients.

Asthma, bronchial hyper-responsiveness and Chlamydophila (Chlamydia) pneumonia infection in adult Thai population.

BACKGROUND: The associations between Chlamydophila (Chlamydia) pneumonia infection and chronic asthma or bronchial hyper-responsiveness (BHR) have been inconclusive. OBJECTIVE: We aimed to determine the association between C. pneumonia infection and asthma as well as BHR in the adult Thai population. MATERIAL AND METHOD: This nested case-control study retrieved the data from a nation-wide Respiratory Health Survey (2001-02) in the adult population (age 20-44 year) in Thailand. Each subject underwent questionnaire interview, spirometry, bronchoprovocative test, skin prick test for common aeroallergens and venous blood collection. Subjects with BHR (n = 79) including those with asthma (n = 52), were randomly selected as cases. Subjects without BHR or asthma were also randomly selected as the control (n = 137). We used the stored serums for the C. pneumonia serologic assay including IgA, IgG and IgM by microimmunofluorescence (MIF) technique. RESULTS: There is no significant relationship between chronic Chlamydia infection (IgG > or = 1:512 and IgA > or = 1:40) and BHR or asthma. Higher IgM was found in subjects with BHR when compared with the control group (p = 0.04). The IgM titer > or = 1:10 was associated with BHR with borderline significance (odds ratio 1.98; 95% CI 0.98-4.00; p = 0.05). Logistic regression analysis revealed no evidence of confounding effects for age, sex and atopy. However mite allergy seems to be an effect modifier of the relationship between the recent Chlamydia infection and BHR. CONCLUSION: The present study does not support the hypothesis about the association between persistent C. pneumonia infection and chronic asthma. However the recent infection may be related with bronchial hyper-responsiveness particularly in those without allergy to house dust mite.

Prevalence of bronchial hyperresponsiveness and asthma in the adult population in Thailand.

OBJECTIVES: We conducted a nationwide cross-sectional survey of respiratory health in adults aged 20 to 44 years during 2001 to 2002 to determine the prevalence of bronchial hyperresponsiveness (BHR) and asthma in the adult Thai population. DESIGN: Subjects were selected by a multistage stratified random sampling. The stratification was done on geographic area, age group, and sex. Subjects were interviewed with questionnaires and underwent spirometric testing. Methacholine challenge tests were performed on all subjects without contraindication to determine BHR defined as the provocative concentration of methacholine producing a 20% fall in FEV(1) < or = 8 mg/mL. Definite asthma was defined as BHR present with any asthma symptom within the past 12 months or demonstrated reversible airflow obstruction. Current diagnosed asthma was defined as previous physician-diagnosed asthma and any asthma symptom within the past 12 months or currently receiving asthma medication. RESULTS: The study population was from 20 provinces of five geographic regions of Thailand and included 1,882 women and 1,572 men. The prevalence of BHR was 3.31% (95% confidence interval [CI], 2.68 to 3.94). However, if subjects with positive reversibility test results were included, the prevalence increased to 3.98% (95% CI, 3.30 to 4.67). The prevalence of definite asthma was 2.91% (95% CI, 2.32 to 3.50), whereas the prevalence of current diagnosed asthma by the questionnaire interview was 2.15% (95% CI, 1.66 to 2.63). The kappa index of the agreement between both definitions of asthma was 0.40, indicating poor to fair agreement. CONCLUSION: The prevalence of BHR and asthma in the adult Thai population is relatively low as compared with western countries.

Acute respiratory illness in patients with COPD and the effectiveness of influenza vaccination: a randomized controlled study.

STUDY OBJECTIVES: To determine the effectiveness of influenza vaccination on influenza-related acute respiratory illness (ARI) and overall ARI in patients with COPD, and its relationship to the degree of airflow obstruction. DESIGN: Stratified, randomized, double-blind, placebo-controlled trial. SETTING: From June 1997 to November 1998 at a single university hospital. PATIENTS AND INTERVENTIONS: One hundred twenty-five patients with COPD were stratified based on their FEV(1) as having mild, moderate, and severe COPD. Within each group, they were randomized to the vaccine group (62 patients who received purified, trivalent, split-virus vaccine) or the placebo group (63 patients). MEASUREMENTS: The number of episodes and severity of total ARI, classified as outpatient treatment, hospitalization, and requirement of mechanical ventilation; and the number of episodes and severity of influenza-related ARI. RESULTS: The incidence of influenza-related ARI was 28.1 per 100 person-years and 6.8 per 100 person-years in the placebo group and vaccine group, respectively (relative risk [RR], 0.24 [p = 0.005]; vaccine effectiveness, 76%). The incidences were 28.2, 23.8, and 31.2 per 100 person-years in the patients with mild, moderate, and severe COPD, respectively, in the placebo group, and 4.5, 13.2, and 4.6 per 100 person-years in the patients with mild, moderate, and severe COPD, respectively, in the vaccine group (RR, 0.16 [p = 0.06]; vaccine effectiveness, 84%; RR, 0.55 [p = 0.5]; vaccine effectiveness, 45%; and RR, 0.15 [p = 0.04]; vaccine effectiveness, 85%, in the patients with mild, moderate, and severe COPD, respectively). Bivariate analysis revealed that the effectiveness of influenza vaccination was not modified by the severity of COPD, comorbid diseases, age, gender, or current smoking status. There was no difference in the incidence or severity of total ARI between the placebo group and the vaccine group. CONCLUSIONS: Influenza vaccination is highly effective in the prevention of influenza-related ARI regardless of the severity of COPD. Influenza vaccination does not prevent other ARIs unrelated to influenza. The effectiveness of influenza vaccination in the prevention of overall ARI in patients with COPD will depend on how much the proportion of influenza-related ARI contributes to the incidence of total ARI. Influenza vaccination should be recommended to all patients with COPD.

The cost-effectiveness of a questionnaire as a screening test for chronic obstructive pulmonary disease among the Bangkok elderly.

This study aimed to explore the cost-effectiveness of using a questionnaire as a screening test for Chronic Obstructive Pulmonary Disease (COPD) among the Bangkok elderly residing around Siriraj Hospital. The gold standard used for diagnosing COPD followed the guidelines of the Thoracic Society of Thailand. The questionnaire consisted of 10 questions on smoking status, respiratory symptoms and previous history of pulmonary tuberculosis. There were 3,094 elderly who participated, completed the questionnaire, and underwent spirometry as well as chest radiography in the community. The results showed that elderly individuals who are smokers (> 0.5 pack-year) or have ever experienced sudden cough with chest oppression or dyspnea when the weather changes or who have expectorated more than two tablespoons of sputum would be suspected of having COPD with a sensitiviy of 81.4 per cent (95% CI 79.4-83.4), specificity of 62.2 per cent (95% CI 60.4-64.0) false negative rate 1.2 per cent (95% CI 0.7-1.7) and false positive rate 38 per cent (95% CI 35.3-40.7) and subsequently required spirometry and chest X-ray for definitive diagnosis. The test needed to screen 17 elderly individuals to detect one COPD case at a cost of 1,538 baht. This questionnaire is also a self-assessment tool for COPD screening among the elderly in order to encourage them to seek for early medical attention and it is recommended that this should be publicized via the mass media.

The cost-effectiveness of chest radiography as a screening test for chronic obstructive pulmonary disease among the Bangkok elderly.

Regular screening with chest radiography (CXR) in an annual physical check up of the elderly is most frequently practiced. This study aimed to identify the CXR indices and the cost-effectiveness of CXR as a screening test for Chronic Obstructive Pulmonary Disease (COPD) among the elderly in 124 urban communities of Bangkok around Siriraj Hospital. The gold standard for diagnosing COPD followed the guidelines of the Thoracic Society of Thailand. There were 3,094 subjects who participated, completed spirometry and a CXR. The selected nine indices from PA and lateral CXR for diagnosing COPD were based on the presence of hyperinflation. The positive criteria of each index were reported. The cut-off point of best average accuracy ie, Z score of the CXR was 0.07 with a sensitivity of 75.9 per cent (95% CI 70.2-81.6%), specificity of 72.4 per cent (95% CI 70.8-74.0%) and the best average accuracy of 74.1 per cent (95% CI 72.5-75.7%) whereas the cost-effective cut-off point of a Z score of CXR as a screening test for COPD was 0.04 at the lowest grand total cost. The cost to detect one case of COPD was 2,008 baht and needed to screen 17 elderly. It is suggested that CXR is probably not a suitable screening test for COPD in the elderly due to the complicated derivation of the CXR indices. However, its efficacy may be of some value in in-office diagnosis of COPD.

The most cost-effective screening method for chronic obstructive pulmonary disease among the Bangkok elderly.

Our previous studies demonstrated the high prevalence and incidence of Chronic Obstructive Pulmonary Disease (COPD) among the Bangkok elderly, as well as the cost-effectiveness of a questionnaire, chest radiography, and mini peak expiratory flow rate (miniPEF) as screening tools. This final study aimed to identify the most cost-effective screening method among individual, serial and parallel combinations of the above tools, based on the guidelines for diagnosing COPD of the Thoracic Society of Thailand. There were 3,094 elderly aged 60 years and over in 124 urban communities around Siriraj Hospital who participated and completed all the tests. The results showed that the most cost-effective screening method was the miniPEF at cut-off percentage of 62 per cent of predicted value. This needed to screen 19 elderly people at a cost of 923 baht to detect one case of COPD, with a false negative rate of 1.9 per cent (95%CI 1.3-2.5), a false positive rate of 17.5 per cent (95%CI 15.4-19.6). The questionnaire is the alternative choice of screening tool.

The cost-effectiveness of mini peak expiratory flow as a screening test for chronic obstructive pulmonary disease among the Bangkok elderly.

This study aims to explore the cost-effectiveness of Mini Peak Expiratory Flow (miniPEF) as a screening test for Chronic Obstructive Pulmonary Disease (COPD) among the elderly in 124 urban communities around Siriraj Hospital, using the gold standard of diagnosis based on the guidelines of the Thoracic Society of Thailand. There were 3,094 subjects who participated and completed all the tests. The results showed that the cut-off miniPEF percentage of predicted value of highest average accuracy was 62 per cent. The sensitivity was 72.7 per cent (95% CI 67.0-78.6) and the specificity was 81.1 per cent (95% CI 79.7-82.5) The cost of screening 19 elderly to detect one case of COPD is 923 baht, with a false negative rate of 1.9 per cent (95% CI 1.3-2.5%) and a false positive rate of 17.5 per cent (95% CI 15.4-19.6%). It is suggested that measuring a miniPEF is regarded as one of the cost-effective screening tests for COPD in the elderly.

Comparison between specified percentage and fifth percentile criteria for spirometry interpretation in Thai patients.

OBJECTIVES: The present study was conducted to determine the degree of agreement between the interpretation of spirometry using a specified percentage of predicted value (SPC) and the fifth percentile (FPC) as the cut off between normal and abnormal. METHODOLOGY: Spirometric values were collected for 1754 subjects attending the respiratory service at Siriraj Hospital between February 2000 and April 2001. These values included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, maximal mid-expiratory flow (FEF25-75%) and peak expiratory flow (PEF). A comparison of results between SPC and FPC was performed. The SPC cut-off values for FVC, FEV1, FEV1/FVC, FEF25-75% and PEF were 80% predicted, 80% predicted, 70%, 65% predicted and 80% predicted, respectively. The FPC cut-off values were calculated from reference equations for the Thai population. Inter-rater agreement was calculated as the kappa score. RESULTS: High kappa scores were obtained for FVC (0.84), FEV1 (0.88) and FEF25-75% (0.80). However, poor agreement was found for FEV1/FVC (0.72) and PEF (0.61). When the cut-off values for SPC were modified to 90% of predicted values for FEV1/FVC and to 65% of predicted values for PEF, agreement was substantially improved to 0.92 and 0.89, respectively. CONCLUSIONS: Interpretation by SPC using cut-off values of 80% predicted for FVC and FEV1 and 65% predicted for FEF25-75% resulted in good agreement with FPC. However, the SPC cut-off values for FEV1/FVC and PEF should be modified to 90% predicted and 65% predicted, respectively.

The prevalence and incidence of COPD among urban older persons of Bangkok Metropolis.

COPD substantially affects the national healthcare resource and healthcare cost especially among the older persons. Identifying the accurate prevalence and incidence reflects the scale of problem posed by COPD. This epidemiological study using the criteria for diagnosing COPD based on ratio of FEV1.0/FVC less than 70 per cent and the reversibility of less than 15 per cent increase of post bronchodilator FEV1.0 in the absence of parenchymal lesions and cardiomegaly in CXR (PA and lateral view) revealed the prevalence (1998) of COPD among the 3094 older persons aged 60 years and over in the communities of Bangkok Metropolis 10 km around Siriraj Hospital was 7.11 per cent (95% CI: 6.21-8.01), whereas the incidence (1999) of COPD was 3.63 per cent (95% CI: 2.83-4.43). Both the prevalence and the incidence were increased with increasing age. The disease occurred predominantly among male smokers. The distribution of mild : moderate : severe COPD in the prevalence study was 5.6:2.2:1. The current findings also suggest that tobacco smoking is the prime important cause of COPD and the indoor pollution especially cooking smoke is not significant. In particular, the unexpectedly high incidence compared with prevalence in this population probably represents the warning message to the national policy maker for prompt and effective health promotion and disease prevention to prevent further social and economic loss.