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Biomedical subjects

K C Lun

Publications and source records attributed to K C Lun.

At least 19 recordsLinked to original sources

New user interfaces.

Usability of a computer-based information system has three components: user-friendliness, acceptance and user-competence. These are important considerations in human-computer interface designs. So far, visual/manual interface techniques have dominated data-capture activities in hospital settings. Despite the improvements made in these areas, usability issues still remain over the use of such I/O devices like the computer keyboard, touch-sensitive screens, light pen and bar codes. This paper will examine two of the newer user interfaces that have emerged in recent years which can potentially improve computer usability in the healthcare setting. These are voice and pen technologies. Speech as a medium for communicating with computers has several advantages. It gives users freedom of movement away from a computer terminal. It further allows users to enter or receive data while engaged in other activities. For example, a doctor can simultaneously examine a patient and record his findings using voice input. The use of pen technology also liberates the physician and other healthcare workers from the keyboard and monitor. It gives them mobility, facilitates eye contact with patients and most importantly, allows them to tap the newest of computer hardware and software technology with the oldest of communication tools--the pen. Healthcare facilities are beginning to explore the use of these two technologies to improve on user-acceptance and user-competence. Some examples of their successful applications will be given.

Handwriting

The role of information technology in health care cost containment.

There is currently global concern over rising healthcare costs which has come at a time when many countries are beginning to see the tangible benefits of implementing information technology (IT) in healthcare. By having the right IT infrastructure, health facilities can achieve substantial cost savings by cutting down on hassles and wastage through timely availability of information. This paper examines the areas in healthcare in which information technology has been demonstrated to have effectively contributed to cost savings.

Cost Control

Mortality analyses of the 1990 Singapore population: I. General life tables.

General life tables for the 1990 Singapore resident population are given in this paper. Analyses were carried out separately for males and females for all ethnic groups as well as for Chinese, Malays and Indians. Average fractions of the last age interval lived were used to give a more precise derivation of the life table death rates from their corresponding age-specific death rates. The results show that in 1990, Singapore males had achieved a life expectancy at birth of 73.7 years while the females had attained a level of 78.6 years. These levels were comparable to those of many developed countries. Other interesting features include higher differentials in the life expectancies between sexes among the Chinese and the Indians taking over the Malays for second placing in terms of life expectancy at birth for both sexes. As a result, the Indians registered a 12% gain in life expectancy at birth for males for the decade 1980 to 1990, compared to only 7.1% for Chinese and 4.4% for Malays as well as nearly 10% for females compared to only 6.2% for Chinese and 6.3% for Malays. A subsequent paper will highlight the results of multiple-decrement life table analyses which will summarise the mortality of the 1990 Singapore resident population for various component causes of death rather than for all causes combined.

Adolescent

A comparative study of calcipotriol ointment and tar in chronic plaque psoriasis.

The antipsoriatic efficacy, tolerability and safety of calcipotriol ointment was compared with tar in a prospective, right/left randomized, investigator-blinded controlled study. Calcipotriol ointment 50 micrograms/g twice daily was applied to one-half of the body. On the opposite side, white soft paraffin was applied in the morning, and coal tar solution BP 15% v/w in aqueous cream in the evening. Thirty patients with stable chronic plaque-type psoriasis were recruited. Assessments were made at 2, 4 and 6 weeks. Three patients were withdrawn from the study. A decrease in PASI score was seen on both sides at 2, 4 and 6 weeks. The differences from baseline between the two treatments were statistically significant in favour of calcipotriol. Improvement with calcipotriol was rapid in the first 2 weeks of treatment. With tar, significant improvement occurred only after 4 weeks of treatment. The differences in the scores for erythema, induration and desquamation from baseline between the two treatments were also statistically significantly in favour of calcipotriol at all evaluation points. Seven patients developed irritation on the calcipotriol-treated side, but there were no adverse effects on the tar-treated side. In two patients, itching associated with psoriasis was reduced by the calcipotriol. Although the mean serum calcium and phosphate levels remained within the normal ranges after 6 weeks' treatment, there were significant changes in their values compared with baseline.

Administration, Cutaneous

Racial differences in fetal morphometry in Singapore.

A systematic collection of fetal morphometric measurements was started seven years ago in 1987 with the prospective entry of data into personal computer-based stations in the Department of Obstetrics and Gynaecology, Singapore General Hospital. A cross-sectional study was done, comparing 2392 Chinese fetuses with 2117 Malay fetuses and 459 Indian fetuses from 18 to 40 weeks. The mean values of the head circumference (HC), abdominal circumference (AC) and femur length (FL) of the 3 ethnic groups were analysed. There were no statistical significant differences in the head circumference and abdominal circumference of Chinese, Malay and Indian fetuses in Singapore. The Chinese and Malay fetal femur length appeared similar but were apparently shorter than the Indian femur length. Nomograms of head circumference, abdominal circumference and femur length were constructed for application to fetuses of all 3 ethnic groups.

Abdomen

Age-related changes in normal Chinese hearts.

The heart weights, ventricular wall thickness and valve circumferences were measured in 507 autopsy specimens of normal hearts from persons aged from 10 to 90 years. The heart weights increased with age and were greater in the males than in the females, except from the 6th to 8th decades where they were reversed. The body weight was the best predictor of heart weight. The ventricular wall thickness in males did not differ significantly from that in females. The values of the indexed left ventricular wall thickness (i.e. values divided by BSA) in the females exceeded those in the males from the 6th to 9th decades. The mean valve circumference was greater in the males but it was significant (P < 0.05) only for the tricuspid valves at the 9th decade of life. The pulmonary valve circumferences were greater than the aortic for all decades and the ratio of the aortic to pulmonary valve circumference remained constant. In the clinical evaluation of the specimens of Chinese hearts, the absence of the aged-related dilatation of the aorta described in Caucasian hearts should be duly taken into account.

Adolescent

Relationships between cigarette smoking, blood pressure and serum lipids in the Singapore general population.

In a cross-sectional random survey of the whole of Singapore (2143 subjects aged 18-69 years), cardiovascular risk factors were measured by standardized techniques. For the analysis in the 18-69 year age group there was adjustment for ethnic group, age, body mass index, alcohol consumption and physical activity. Among serum lipids, high density lipoprotein (HDL-) cholesterol and fasting triglyceride were inversely related with partial correlation coefficients (r) of males -0.34 (P < 0.001) and females -0.26 (P < 0.001). There were no relationships between blood pressure and serum lipids except for direct ones with fasting triglyceride, being males (systolic r = 0.06, P = 0.066 and diastolic r = 0.12, P < 0.001) and females (systolic r = 0.11, P < 0.001 and diastolic r = 0.13, P < 0.001). Cigarette smoking, in males, was related to systolic blood pressure (inversely), with, compared to non-smokers, a reduction of 1.3 mm Hg (1.1%) in light smokers, 3.8 mm Hg (3.1%) in moderate smokers and 4.6 mm Hg (3.7%) in heavy smokers; there was no clear relation with diastolic blood pressure. Cigarette smoking, in males, was related to HDL-cholesterol (inversely), even after further adjustment for fasting triglyceride, with compared to non-smokers reductions of 0.03 mmol/l (3.4%) in light smokers, 0.09 mmol/l (10.3%) in moderate smokers and 0.12 mmol/l (13.8%) in heavy smokers. Cigarette smoking was related to fasting triglyceride (directly) but this was removed by further adjustment for HDL-cholesterol. Cigarette smoking was not related to low density lipoprotein cholesterol. These results are compared to those of other surveys.

Adolescent

Corneal arcus and cardiovascular risk factors in Asians in Singapore.

This study was a cross-sectional random survey of the whole of Singapore, based on 2143 subjects (aged 18-69 years, response rate 60.3%). The presence of corneal arcus was determined by a doctor using the naked eye in good light. Cardiovascular risk factors were measured by standardized techniques. The prevalence rates overall of corneal arcus were: 18-29 years (males 0.5%, females 0.3%), 30-49 years (males 18.1%, females 13.3%) and 50-69 years (males 70.7%, females 55.3%). In the 30-49 age group, people with arcus had higher serum low density lipoprotein (LDL) cholesterol concentrations than people without arcus, the mean differences being, males 0.31 mmol/l (P = 0.040) and females 0.62 mmol/l (P less than 0.001) with an increased likelihood of having values greater than 5.5.mmol/l of males 1.8 (95% confidence interval (95% CI): 1.0-3.4) and females 2.6 (95% CI: 1.4-4.8). There were no significant differences for LDL-cholesterol in the 50-69 age group. Arcus was weakly associated with fasting plasma glucose in the 30-49 age group. Arcus was not associated with serum high density lipoprotein (HDL) cholesterol, serum fasting triglyceride, blood pressure and cigarette smoking. It is concluded that while corneal arcus is primarily an age-related change, its formation is accelerated by high serum LDL-cholesterol so that in people under 50 years it is a marker for the condition.

Adolescent

Normal standard of pubertal development in Singapore school children.

A cross sectional study of the pubertal status of normal school children in Singapore was performed in 1987. The results of the data analysis are presented as an update from the last survey performed in 1977. The norms of pubertal development in boys and girls are thus defined.

Adolescent

Cardiovascular diseases in Chinese, Malays, and Indians in Singapore. I. Differences in mortality.

STUDY OBJECTIVE: The aim of the study was to analyse differences in mortality from the main cardiovascular diseases (ischaemic heart disease, hypertensive disease, and cerebrovascular disease) among Chinese, Malays, and Indians in Singapore. DESIGN: The study was a survey using national death registration data in Singapore for the five years 1980 to 1984. The underlying cause of death, coded according to the ninth revision of the International Classification of Diseases, was taken for the analyses. SETTING: The study was confined to the independent island state of Singapore, population 2.53 million (Chinese 76.5%, Malays 14.8%, Indians 6.4%, Others 2.3%). Death registration is thought to be complete. SUBJECTS: All registered deaths in the age range 30-69 years during the study period were analysed by ethnic group. MEASUREMENT AND MAIN RESULTS: Indians had higher mortality from ischaemic heart disease than the other ethnic groups in both sexes, with age-standardised relative risks of Indian v Chinese (males 3.8, females 3.4), Indian v Malay (males 1.9, females 1.6), and Malay v Chinese (males 2.0, females 2.2). The excess mortality in Indians declined with age. For hypertensive disease Malays had the highest mortality, with age-standardised relative risks of Malay v Chinese (males 3.4, females 4.4), Malay v Indian (males 2.0, females 2.5), and Indian v Chinese (males 1.6, females 1.6). For cerebrovascular disease there was little ethnic difference except for lower rates in Chinese females, with age-standardised relative risks of Malay v Chinese (males 1.1, females 1.9), Malay v Indian (males 1.0, females 1.1), and Indian v Chinese (males 1.1, females 1.7). CONCLUSIONS: There are significant differences in mortality from the three main cardiovascular diseases in the different ethnic groups in Singapore.

Adult

Cardiovascular diseases in Chinese, Malays, and Indians in Singapore. II. Differences in risk factor levels.

STUDY OBJECTIVE: The aim of the study was to examine cardiovascular risk factors to see how these might explain differences in cardiovascular disease mortality among Chinese, Malays, and Indians in the Republic of Singapore. DESIGN: The study was a population based cross sectional survey. Stratified systematic sampling of census districts, reticulated units, and houses was used. The proportions of Malay and Indian households were increased to improve statistical efficiency, since about 75% of the population is Chinese. SETTING: Subjects were recruited from all parts of the Republic of Singapore. SUBJECTS: 2143 subjects aged 18 to 69 years were recruited (representing 60.3% of persons approached). There were no differences in response rate between the sexes and ethnic groups. MEASUREMENTS AND MAIN RESULTS: Data on cardiovascular risk factors were collected by questionnaire. Measurements were made of blood pressure, serum cholesterol, low and high density lipoprotein cholesterol, fasting triglycerides and plasma glucose. In males the age adjusted cigarette smoking rate was higher in Malays (53.3%) than in Chinese (37.4%) or Indians (44.5%). In both sexes, Malays had higher age adjusted mean systolic blood pressure: males 124.6 mm Hg v 121.2 mm Hg (Chinese) and 121.2 mm Hg (Indians); females 122.8 mm Hg v 117.3 mm Hg (Chinese) and 118.4 mm Hg (Indians). Serum cholesterol, low density lipoprotein cholesterol and triglyceride showed no ethnic differences. Mean high density lipoprotein cholesterol in males (age adjusted) was lower in Indians (0.69 mmol/litre) than in Chinese (0.87 mmol/litre) and Malays (0.82 mmol/litre); in females the mean value of 0.95 mmol/litre in Indians was lower than in Chinese (1.05 mmol/litre) and Malays (1.03 mmol/litre). Rank prevalence of diabetes for males was Indians (highest), Malays and then Chinese; for females it was Malays, Indians, Chinese. CONCLUSIONS: The higher mortality from ischaemic heart disease found in Indians in Singapore cannot be explained by the major risk factors of cigarette smoking, blood pressure and serum cholesterol; lower high density lipoprotein cholesterol and higher rates of diabetes may be part of the explanation. The higher systolic blood pressures in Malays may explain their higher hypertensive disease mortality.

Adolescent

Diabetes mellitus and its chronic complications in Singapore: an increasing healthcare problem.

We studied the prevalence of diabetes mellitus in Singapore and compared it to the study conducted ten years previously. A rise in prevalence rates from 2.0% to 4.7% was demonstrated. Impaired glucose tolerance (IGT) was studied for the first time, and a prevalence rate of 0.9% was found. Findings on chronic complications of diabetes were also reported. A high frequency of coronary heart disease and hypertension were detected in both diabetic and IGT subjects. Obesity and hyperlipidaemia were identified as important risk factors. This study demonstrates the scope and impact of diabetes mellitus as a major healthcare problem in Singapore. Strategies directed at prevention and control of this disease needs to be implemented so as to check its rising trend.

Adolescent

Harnessing information technology to revolutionise teaching, research and consultative service in health statistics.

Computers have traditionally been associated with health statistics because of the need to manage, process and analyse data. Over the last two years, the Division of Biostatistics and Health Informatics of the Department of Community, Occupational and Family Medicine at the National University of Singapore has been actively looking into ways in which informatics and telematics could be usefully applied to teaching and research in health statistics and in the provision of a statistical information service. This paper describes three projects, originating from the National University of Singapore, which provide an effective demonstration of the application of modern technology to an age-old discipline.

Computer-Assisted Instruction

General anesthesia with propofol (continuous intravenous infusion) supplemented with nitrous oxide: comparison with isoflurane.

Thirty adult surgical patients (ASA I-II) undergoing superficial operations of short duration (about 1h) were arbitrarily divided into two groups. In group A (n = 15), anesthesia was induced with propofol, 2 mg/kg, iv. After endotracheal intubation with the aid of succinylcholine (1 mg/kg, iv), anesthesia was maintained by continuous iv infusion of propofol (0.05-0.2 mg/kg/min) with nitrous oxide and oxygen (2:1). In group B (n = 15), induction and endotracheal intubation were accomplished using thiopental (4 mg/kg, iv) and succinylcholine (1 mg/kg). Anesthesia was maintained with isoflurane (0.5-2.0%), nitrous oxide and oxygen (2:1). Atracurium was used in both groups as muscle relaxant. Hemodynamic responses to laryngoscopy and endotracheal intubation and during operation were not significantly different between the two groups. However, recovery to verbal command and orientation was significantly more rapid in the propofol group (7.8 +/- 4.8 min and 11.2 +/- 5.1 min) than in the isoflurane group (15.6 +/- 4.9 min and 22.6 +/- 6.0 min). In conclusion, continuous propofol infusion combined with nitrous oxide and muscle relaxant is suggested as a better method compared with isoflurane for short operations because of more rapid complete recovery.

Adult

A new approach to suppress bucking before extubation--lidocaine through modified endotracheal tube.

The conventional endotracheal tube was modified with an epidural catheter adhered on the concave aspect of it. The opening of the catheter is at the proximal margin of the cuff. Local anesthetic can be injected into the trachea, then desensitize the tracheal mucosa nearby the cuff. Thirty-four female gynecological patients underwent abdominal total hysterectomy were studied and divided into three groups. In group 1, anesthesia was maintained without special management. In groups 2 and 3, 2 mL gentian violet stained 4% lidocaine solution was administered intratracheally by two different methods 60-120 minutes before the conclusion of the surgery. The peak cuff pressures generated by the awakening patients were 53.8 +/- 2.2 cm H2O (mean +/- SE) in group 1, 47.3 +/- 2.5 cmH2O (Group 2) and 36.4 +/- 1.6 cmH2O Group 3) respectively. Bucking before awakening was also evaluated clinically and showed 100%, 73% and 0% in each group. Intratracheal administration of lidocaine in dose of 2 mL 4% showed significant effect for the suppression of bucking during the recovery of general anesthesia in group 2 and 3 compared with the group 1. Lidocaine administered through the catheter of modified endotracheal tube also resulted in less increase in the peak cuff pressure and even no clinically observed bucking than direct administered through the endotracheal tube. Gag reflex was preserved in all patients and none had suffered from aspiration postoperatively.

Adult

Physical activity in Chinese, Malays and Indians in Singapore.

A population based survey has measured levels of physical activity by questionnaire in persons aged 18 to 69 years in Singapore. Levels of physical activity were classified into high, medium and low based on activity in leisure and at work. The only ethnic difference was that for males a higher proportion were classified as "high" activity in Malays (24.8%) than Chinese (16.0%) and Indians (18.1%). For the overall 18 to 69 age group, it was found that for males, the proportions in the "low" category were Chinese 80%, Malays 70% and Indians 75% while for females it was 95% in all three ethnic groups. As physical activity of sufficient intensity is important in disease prevention and health promotion, more needs to be done on educating the public in Singapore about the benefits of regular exercise.

Adolescent

Alcohol consumption in Chinese, Malays and Indians in Singapore.

A population based survey has measured alcohol consumption by questionnaire in persons aged 18 to 69 years in Singapore. The majority were "occasional/none" drinkers, being males (Chinese 87%, Malays 99% and Indians 80%) and females (Chinese 98%, Malays 100% and Indians 100%). "Heavy" consumption was uncommon in males (Chinese 0.6%, Malays 0% and Indians 1.3%) and absent in females, while "heavy/moderate" drinking was males (Chinese 5.7%, Malays 0.5% and Indians 3.8%) and females (Chinese 0.3%, Malays 0% and Indians 0%). For males, "light" drinking was highest in Indians (15.9%), then Chinese (7.8%) and then Malays (0.5%). This survey indicates that alcohol consumption is not yet a major public health problem in Singapore.

Adolescent

Obesity and body mass indices in Chinese, Malays and Indians in Singapore.

A population based cross-sectional survey has measured body mass indices (BMIs) in Singapore and compared their means and the proportions who are overweight and obese amongst Chinese, Malays and Indians. For males there was little ethnic differences; for the 18-69 age group, the age-adjusted mean BMIs being Chinese 22.3, Malays 23.1 and Indians 22.5. However for females, Malays and Indians were considerably more obese than Chinese; for the 18-69 age group the age-adjusted mean BMIs in Malays (25.1) and Indians (24.6) were significantly greater (p less than 0.001) than in Chinese (22.2). The proportions categorised as overweight or obese (BMI equal to or more than 26 in males and 25 in females) were males (Chinese 16.7%, Malays 22.4%, and Indians 14.0%) and females (Chinese 21.2%, Malays 51.5%, and Indians 42.0%). Health education on the harmful effects of obesity should be targeted especially on Malay and Indian females.

Adolescent