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Biomedical subjects

A Seow

Publications and source records attributed to A Seow.

At least 37 records · Page 2Linked to original sources

Patterns of consultation and treatment for heartburn: findings from a Singaporean community survey.

BACKGROUND: The prevalence of reflux-type symptoms among community individuals in Singapore is low. AIM: To describe the healthcare-seeking behaviour of those subjects with heartburn. METHODS: A cross-sectional survey, using a reliable and valid questionnaire, was carried out on a race-stratified random sample of residents, aged 21-95 years, in a Singaporean town; 93% responded (n = 696). RESULTS: The ethnic-adjusted prevalence of heartburn for the past 1-year was 4.6%. Sixteen (30%) of the 53 heartburn sufferers had sought consultation for their symptoms. They were more likely to have severe heartburn (P<0.001), and to have complained of nocturnal awakening due to heartburn (P<0.05) than those who did not present to medical attention. Ethnic origin did not influence the consultation pattern. Only 18 (34%) of the 53 heartburn sufferers received pharmacological therapy for their symptoms. The most commonly used medication was antacid. Medication use was associated with symptom severity (P<0.05), but not ethnicity. CONCLUSIONS: Heartburn is uncommon in the general population of Singapore. Few heartburn sufferers seek medical attention, and most do not receive medications for symptomatic control. The decision to seek medical advice and/or to medicate was generally linked to symptom severity, but not to ethnicity.

Adult↗

NAT2 slow acetylator genotype is associated with increased risk of lung cancer among non-smoking Chinese women in Singapore.

Among non-smokers, the factors resulting in lung carcinogenesis are poorly understood. We conducted a hospital-based case-control analysis of 294 Chinese women, of whom 217 were non-smokers, to evaluate the role of polymorphic N-acetyltransferase (NAT2) as a susceptibility factor for the disease. The proportion of slow acetylator genotypes among non-smoking cases (n = 92) and controls (n = 125) was 38.0 and 24.0%, respectively [odds ratio (OR) 2.0, 95% confidence interval (CI) 1.1-3.7]. No effect of NAT2 genotype was seen among smokers. Among non-smokers, the effect was marked for adenocarcinomas (OR 2.1, 95% CI 1.1-4.0). As NAT2 activity is known to modify risk of arylamine-induced carcinogenesis, our results suggest that exposure to arylamines in the environment may play a role in risk of lung cancer among non-smokers.

Acetylation↗

Applications of new technology in molecular epidemiology and their relevance to occupational medicine.

Technological advances in molecular biology over the past 2 decades have offered more complex techniques that can be used to study the role of specific exogenous agents and host variables that cause ill health. Increasingly, studies in human populations use this new technology, combined with epidemiological methods, to shed light on the understanding of the biological processes associated with development of disease. This approach has many potential applications in occupational and environmental medicine (OEM), and some aspects of the work in this growing field are reviewed. An understanding of biochemistry and genetics at the molecular level, specific knowledge on metabolism and mechanisms of action, and epidemiology have become increasingly important for the OEM practitioner. This is necessary to consider the major question of validation and relevance of these molecular biomarkers. As end users, OEM practitioners should also consider the impact of these advances on their practices. For example, the availability of genetic tests to identify susceptible workers raises issues of ethics, individual privacy, right to work, and the relevance of such tests. Several studies have presented data on the association of environmental measurements and various biomarkers for internal and biologically effective dose, genetic polymorphisms, and early response markers. Given the limitations of individual molecular biomarkers in assessing risk to health, and the multifactorial nature of environmental disease, it is likely that such an approach will increase our understanding of the complex issue of mechanisms of disease and further refine the process of risk assessment.

Genetic Markers↗

A cross-sectional survey of physical activity among middle aged women in Singapore.

OBJECTIVES: To assess the extent to which middle-aged women in Singapore engage in physical activity of a level which would result in long-term health benefits, and to determine the factors associated with this. METHODS: We conducted a cross-sectional survey of women aged between 35 and 60 years residing in Marine Terrace. A standardised questionnaire incorporating a modified Seven-Day Recall Questionnaire was used to record the level and type of physical activity engaged in over the past week. Demographic information and factors promoting or discouraging sports and exercise were also elicited. The total energy expenditure for household, occupational and sports activities of moderate intensity and above was calculated using metabolic equivalents (METs) in kcal/kg/week. RESULTS: Of the 341 respondents, 50.7% reported engaging in at least moderate activity for 30 minutes or more every day during the past week, thus fulfilling the WHO recommendations on physical activity. Housework contributed significantly to the energy expenditure on these activities among our target population. After adjusting for age, body mass index and educational level, we found that housewives without domestic help were most likely to fulfill the WHO recommendations. Housewives or working women with domestic help were the two groups at highest risk of low physical activity. A lack of time was the reason most commonly cited for not engaging in sports or exercise. CONCLUSION: Studies assessing physical activity in relation to disease risk among women should include domestic work in addition to the traditional leisure-time activities. There is a scope for further efforts to improve the level of activity in this population, which could be facilitated by the support of health professionals, employers and family members.

Adult↗

Results of intermediate measures from a population-based, randomized trial of mammographic screening prevalence and detection of breast carcinoma among Asian women: the Singapore Breast Screening Project.

BACKGROUND: Although increasing rates of breast carcinoma incidence have been observed in Asian countries, appropriate strategies for detecting early stage breast carcinoma in such communities have been difficult to formulate, particularly because no large population screening trial specifically involving Asian women has been reported. The objective of this study was to evaluate the effectiveness and quality of mammography as a screening technique for Singaporean women, who are predominantly Chinese. METHODS: In this prospective study, 166,600 women in Singapore ages 50-64 years were randomized to either 2-view mammography without physical examination (67,656) or observation (97,294, controls) over 2 years. RESULTS: Of these women, 28,231 (41.7%) responded and were screened; they were more likely to be married, have more formal education, be working, be Chinese, and be in a higher socioeconomic group (P < 0.001 for all variables). To assess for response bias that could affect outcome, results were also evaluated for nonrespondents (n = 39,425). The incidence rate of cancers among nonrespondents (1 per 1000 woman-years) was less than the 1.3 in women not invited to have screening (P = 0.03, relative risk [RR], 1.3; 95% confidence interval [CI], 1.0-1.7). However, cancers arising from nonrespondents did not differ significantly in stage distribution when compared with cancers within the control group. For every 1000 women screened, 4.8 cancers were detected. The prevalence ratio (the number of cancers detected per 1000 women at first screening divided by the corresponding incidence rate in controls per year) was 3.6 for screened women and 2.4 for women invited to have screening. The majority of cancers detected through screening were early stage, with 64% as either ductal carcinoma in situ (26%) or Stage I disease (38%) and was significantly more than the corresponding 26% in women not invited to have screening (P < 0.001). When only invasive cancers were considered, screened women still had more early cancers, with 65% having no lymph node involvement, compared with 47% in the group not invited to have screening (P = 0.001; RR, 1.4; 95% CI, 1.2-1.7). Women who were screened had half the risk of having Stage II or later cancers (P < 0.0001; RR, 0.5; 95% CI, 0.4-0.7) when compared with women not invited to have screening. This higher detection rate of early cancers through screening was accomplished with acceptable recall rates of 8% for further mammographic films or physical examination and a biopsy rate of 1.0% (10 per 1000 women screened). The interval cancer rate was 2.1 per 10,000 women screened in the first year of follow-up. CONCLUSIONS: These positive results of intermediate measures suggest that, in Asian communities, screening mammography could be an important modality for detecting early stage breast carcinoma. However, the low compliance rates suggest that health education efforts must focus on issues related to acceptability if such programs are to succeed.

Aged↗

Lung cancer among Chinese females in Singapore 1968-1992: time trends, dialect group differences and implications for aetiology.

BACKGROUND: Chinese females are distinguished internationally as having relatively high lung cancer incidence rates despite a low prevalence of cigarette smoking. In Singapore, this population comprises several dialect groups which have origins in different regions in China, each with its own traditional cultural practices. METHODS: An analysis of 4029 incident cases of the disease notified to the Singapore Cancer Registry for 1968-1992 was undertaken to provide some insight into important aetiologic factors among these women. RESULTS: The age-standardized incidence rate of lung cancer rose from 17.3 per 100,000 woman-years in 1968-1972 to 23.0 in 1978-1982 before falling off in more recent years. Age-period-cohort analysis indicated significant period and birth cohort effects, with the risk being highest for women born around 1908. Between the major dialect groups, Cantonese women had a significantly high rate compared with Hokkiens (relative risk [RR] = 2.6, 95% CI: 2.4-2.8). Histologically, there appears to be an increase in the proportion of adenocarcinomas diagnosed over this period (25.8% in 1968-1972 to 51.3% in 1988-1992). CONCLUSION: Our results suggest that traditional practices which have decreased over the years, and are more prominent among Southern Chinese, may play a part in the aetiology of lung cancer locally.

Adenocarcinoma↗

Prevalence of gastrointestinal symptoms in a multiracial Asian population, with particular reference to reflux-type symptoms.

OBJECTIVE: Data on the epidemiology of chronic gastrointestinal symptoms in the East are limited. The aims of this study were to estimate the prevalence of chronic gastrointestinal symptoms in Singapore and to determine whether ethnic differences in the prevalence of these symptoms exist. METHODS: A cross-sectional survey, using a reliable and valid questionnaire, was carried out in a race-stratified random sample of residents aged 21-95 yr (mean+/-SD, 40+/-1 yr) in a Singaporean town; 93% responded (n=696). RESULTS: The ethnic-adjusted prevalence of chronic abdominal pain, frequent dyspepsia, irritable bowel syndrome, chronic constipation, chronic diarrhea, and frequent reflux were 5.7% (95% confidence interval [CI], 3.3-8.1), 7.9% (95% CI, 5.0-10.8), 2.3% (95% CI, 0.8-3.9), 3.9% (95% CI, 1.9-5.9), 4.5% (95% CI, 2.3-6.7), and 1.6% (95% CI, 0.6-2.6), respectively. There were no ethnic differences in the prevalence of any of these symptom categories except for reflux-type symptoms, which were more common among Indians (7.5%; 95% CI, 4.4-11.7) than Chinese (0.8%; 95% CI, 0.1-3.0) or Malays (3.0%; 95% CI, 1.26.1). CONCLUSION: The prevalence of all types of chronic gastrointestinal symptoms in the general population of Singapore was low compared with those in the West. Chronic gastrointestinal symptoms were equally prevalent in the three major ethnic groups except for reflux-type symptoms, which were more common among Indians than Chinese or Malays.

Abdominal Pain↗

Prevalence of snoring and sleep breathing-related disorders in Chinese, Malay and Indian adults in Singapore.

This study investigated the prevalence of snoring and symptoms of sleep breathing-related disorders in the multi-ethnic population of Singapore (3 million people, comprising 75% Chinese, 15% Malay and 7% Indian). A multistaged, area cluster, disproportionate stratified, random sampling of adults aged 20-74 yrs was used to obtain a sample of 2,298 subjects (65% response), with approximately equal numbers of Chinese, Malay and Indian and in each 10 yr age group. An interviewer-administered field questionnaire was used to record symptoms of snoring and breathing disturbances during sleep witnessed by a room-mate and other personal and health-related data. The weighted point estimate (and 95% confidence interval) of the whole population prevalence of snoring was 6.8% (53-83). There were pronounced ethnic differences among Chinese, 6.2% (4.4-8.1); Malay, 8.1% (6.1-10.2) and Indian, 10.9% (85-13.4). The minimum whole population prevalence by the most restricted symptom criteria for defining sleep breathing-related disorder was 0.43% (0.05-0.8%). Similar marked ethnic differences in rates were observed using various symptom criteria. The ethnic differences in sleep breathing symptoms paralleled the differences in body mass index, neck circumference and hypertension, but statistically significant differences remained after adjustment for sex, age and these known associated factors. Marked ethnic differences in snoring and sleep breathing-related disorders were observed in Chinese, Malays and Indians in Singapore, which were only partly explained by known factors of sex, age and body habitus.

Adult↗

A randomized trial of the use of print material and personal contact to improve mammography uptake among screening non-attenders in Singapore.

The Singapore Breast Screening Project was a nationwide study inviting a random sample of women between the ages of 50 and 64 years for mammography at one of two hospital-based screening centres over two years. The current study was undertaken to determine if (1) mailed health educational material alone, or (2) the same material delivered during a home visit made to the subject and her family would increase the uptake among Singapore women who had not responded to two previous invitations for mammographic screening as part of the Project. This randomized trial employed a standard second reminder letter (R), the same letter packaged with health education material designed for the project (RP) and the addition of a home visit to make contact with the woman and her family (RV). The outcome measure of interest was the proportion of women in each group subsequently attending for screening. The study population comprised 1500 non-attenders whose names appeared consecutively in the database of the larger screening centre in this Project. These were randomized into three groups of 500 each. In total, they broadly resembled the national population in ethnic composition (72.3% Chinese, 17.8% Malays, 9.0% Indians and 0.8% Others). By the end of the project, 7.0% of women in group R and 7.6% in group RP responded to the invitation. In group RV, 428 homes were visited at least once and contact was made with the subject and her family member in 306 (71.5%) cases. Subsequently, 13.3% of the women visited attended for screening. The rate ratio for attendance in group RP compared with group R was 1.09 (95% CI 0.70 to 1.70) and for group RV compared with R, 1.90 (1.27 to 2.84). When analyzed by groups originally assigned to, women in group RV remained significantly more likely to attend than those in groups R or RP. The marginal cost of a home visit, based on this study, was $25.04 per additional woman screened. Our results suggest that the response to a second reminder is generally low and that additional print material does not improve screening attendance in this group of initial non-attenders. Personal contact with the family through a home visit appears to increase uptake, and may be helpful particularly among women who have less frequent contact with the health care system.

Aged↗

Isoflavonoid levels in spot urine are associated with frequency of dietary soy intake in a population-based sample of middle-aged and older Chinese in Singapore.

Soy products contain high amounts of isoflavonoids, which have been shown to exhibit possible cancer-protective properties. Chinese populations in Asia, in particular, have a high level of soy intake and a relatively low risk of hormone-dependent cancers. In this study, we assessed the distributions of dietary soy isoflavonoids (daidzein, genistein, and glycitein) and urinary soy isoflavonoids and their metabolites (daidzein, genistein, glycitein, equol, and O-desmethylangolensin) among 147 Singapore Chinese (76 men and 71 women) ages 45-74 years, who are participants of the Singapore Cohort Study on diet and cancer. Urinary values were measured from spot samples collected 10-20 months following recruitment, when usual dietary habits were assessed by a structured food frequency/portion size questionnaire administered in person. Dietary levels of daidzein and genistein were comparable within individuals and about seven times higher than the level of dietary glycitein. All three dietary isoflavonoids showed an approximately 3.5-fold difference between the 25th and 75th percentile values. Similarly, daidzein was the most abundant and glycitein the least abundant of the five isoflavonoid compounds in urine. There was a 4.9-fold difference between the 25th and 75th percentile values for the sum of the five urinary isoflavonoids. Among study subjects, there were statistically significant, dose-dependent associations between frequency of overall soy intake and levels of urinary daidzein (two-sided P = 0.03) and sum of urinary daidzein, genistein, and glycitein (two-sided P = 0.04). In contrast, there were no associations between frequency of overall soy intake and levels of the two daidzein metabolites (equol and O-desmethylangolensin) in urine (two-sided P = 0.85 and 0.34, respectively). We suggest that within the range of exposures experienced by Singapore Chinese, urinary level of daidzein or the sum of daidzein, genistein, and glycitein obtained from a spot sample can serve as a biomarker of current soy consumption in epidemiological studies of diet-disease associations.

Aged↗

Population-based mammographic screening in Singapore: what are participants' views?

Mammographic screening for breast cancer has been shown to be an effective tool for reducing mortality from the disease in many studies in the West, if high technical quality and acceptance by the target population are achieved. The objective of the Singapore Breast Screening Project was to determine if the same results could be obtained among local women by inviting a random sample of 69,500 women aged 50 to 64 years for a screening mammogram over two years. To date, the compliance rate among the women invited has been 41.7%. The objective of the present substudy was to determine participants' views on the accessibility and acceptability of organised mammographic screening. Of the three hundred women interviewed, 85% were satisfied with the information given prior to the visit, while 67% needed to change the original appointment given. The majority were satisfied with aspects of the visit such as waiting time, privacy and explanation given during the test. However, 35.1% reported at least moderate discomfort during mammography. A substantial proportion (39.7%) of attenders felt that there was very little hope of cure even if cancer was detected early. When asked the most important reason for attending, most indicated they had taken the opportunity for a free check-up to be assured they were well. Almost all (95.7%) reported a willingness to be screened again, but most would not be willing to pay for a mammogram at the current rates.

Appointments and Schedules↗

Cross cultural adaptation and validation of the Chinese Health Assessment Questionnaire for use in rheumatoid arthritis.

OBJECTIVE: The Health Assessment Questionnaire - Disability Index (HAQ), used as a disability and outcome measurement in rheumatoid arthritis (RA), has been validated in several languages, but not in Chinese. Our aim was to validate the Chinese version of HAQ (Chinese-HAQ) to suit the needs of Chinese speaking patients with RA in an Asian setting. METHODS: The original HAQ was modified in the context of Chinese culture and translated into Chinese by 2 translators aware of the objective of the questionnaire. The Chinese HAQ was self-administered by 42 patients with RA during their routine followup visit and one week later. RESULTS: The test-retest reliability assessed using Spearman's correlation coefficient was 0.84. Between dimensions measured in the HAQ, the highest test-retest reliability was observed for walking (Spearman correlation coefficient rs=0.80) and the lowest was for eating (rs=0.54). The internal consistency of the scale using Cronbach's alpha was high at 0.86. In terms of criterion validity, the Chinese-HAQ score was found to correlate well with American College of Rheumatology functional status (rs=0.501, p=0.01). The Chinese-HAQ scores also correlated well with markers of disease activity such as patient's perception of pain measured on a visual analog scale (rs=0.55, p < 0.001), grip strength in mm Hg (rs=-0.55. p < 0.001 ), and physician's assessment of disease activity (rs=0.59, p < 0.001). CONCLUSION: The Chinese HAQ is a reliable and valid instrument for studies measuring disability of patients with RA in Singapore.

Adult↗

Urinary total isothiocyanate (ITC) in a population-based sample of middle-aged and older Chinese in Singapore: relationship with dietary total ITC and glutathione S-transferase M1/T1/P1 genotypes.

Isothiocyanates (ITCs), degradation products of glucosinolates (which occur naturally in a variety of cruciferous vegetables), have been shown to exhibit chemopreventive activity. These compounds are metabolized in vivo to form the corresponding dithiocarbamates, which are the major urinary metabolites of ITCs, by a pathway involving the glutathione S-transferase (GST) class of enzymes. Using a newly developed assay that measures total ITC (primarily ITC conjugates) in urine, we examined the relationships between cruciferous vegetable intake (obtained from a food frequency/portion size questionnaire administered in person); dietary total ITC level; GSTM1, GSTT1, and GSTP1 genotypes; and levels of total ITC in spot urine samples collected from 246 Singapore Chinese (111 men and 135 women), ages 45-74 years, who are participants of the Singapore Cohort Study on diet and cancer. Consumption level of cruciferous vegetables was high in study subjects (mean consumption = 345 times per year, mean daily intake = 40.6 g), which was >3 times the comparable level of intake in the United States. Mean daily intake of total ITC among study subjects was 9.1 micromol, and there was a 2.5-fold difference between the 25th and 75th percentile values. Seventy-three % of study subjects tested positive for ITC in urine, and there was a 4-fold difference between the 25th and 75th percentile values among the positive subjects. There was a highly significant positive association between dietary intake and urinary excretion levels of total ITC (two-sided P = 0.0003) that was stronger than the association between overall cruciferous vegetable intake and urinary ITC level, which also was statistically significant (P = 0.0004). There was no difference in urinary ITC levels between GSTM1-null and GSTM1-positive study subjects (P = 0.61) or between subjects with differing GSTP1 genotypes (P = 0.77), but urinary excretion of ITC was significantly higher among GSTT1-positive subjects, relative to GSTT1-null subjects (P = 0.006). The strength of the association between GSTT1 genotype and urinary total ITC level was highly dependent on the level of cruciferous vegetable consumption (or dietary ITC level) in study subjects. Among subjects in the lowest tertile of cruciferous vegetable intake, there was little evidence of an association between GSTT1 genotype and urinary total ITC level (P = 0.67). In contrast, there was a strong and statistically significant association between GSTT1 genotype and urinary total ITC among subjects in the highest tertile of cruciferous vegetable intake (P = 0.02), whereas those in the middle tertile of cruciferous vegetable consumption exhibited an association of intermediate strength (P = 0.04). These results suggest the presence of GSTT1 inducers in cruciferous vegetables.

Age Factors↗

Factors determining acceptability of mammography in an Asian population: a study among women in Singapore.

Population-based mammographic screening has been shown to be effective in reducing breast cancer mortality in the West. In Singapore, a project carried out to determine the effectiveness of implementing such a program locally invited 28,000 women between the ages of 50 and 64 years for mammography. The current study, which was part of this larger project, was intended to determine factors contributing to the acceptance of mammographic screening among women in Singapore. A questionnaire was administered in-person to 300 attenders and 260 non-attenders. The respondents were compared with respect to basic demographic characteristics, previous preventive behavior, informal social support, and attitudes towards early detection. We found that screening attenders were more likely to be Chinese than Malays (14 percent of the population) or Indians (seven percent), and to be working outside the home (adjusted odds ratio [OR]) = 4.5, 95 percent confidence interval [CI] = 2.6-7.9). A greater proportion of attenders had a history of other screening tests such as the Pap smear (OR = 4.7, CI = 2.6-8.7 for recent smear compared with never having had a smear). They were also more likely to indicate a sense of personal susceptibility to cancer, but did not differ from non-attenders in terms of believing in cancer prevention, or of preferring to be told if they did have cancer. The strongest independent predictor of attendance, however, was encouragement by her spouse or family member. For women in this population to be persuaded effectively to participate in mammographic screening, it would be important to convince family members of the benefits of the test. At the same time, education targeted specifically at women of the appropriate age group should address the issue of the personal relevance of screening for breast cancer.

Breast Neoplasms↗

SLE mortality in an oriental population.

We analysed the causes of 67 deaths, over a 4 y period, in our oriental population with systemic lupus erythematosus (SLE). The median disease duration was 48 +/- 60.5 months (range 1-250 months). The mean age at diagnosis and death were 30 and 35.1 y respectively. SLE alone accounted for death in 30 patients (44.8%), infection in 27 (40.3%), pulmonary embolism in 5 (7.5%), malignancy in 4 (5.9%) and rheumatic heart disease in 1 (1.5%). The major organ involvement in those with active disease at death were SLE related thrombocytopenia (n = 23/44, 52.3%), nephritis (n = 21/44), 47.7%), cerebral lupus (n = 16/44, 36.4%), and pulmonary haemorrhage (n = 12/44, 27.3%). As in other series, SLE and infection were the principal causes of death in our population. During this 4 y period, there was no late death due to atherosclerosis.

Adolescent↗

Non-Hodgkin's lymphoma in an Asian population: 1968-1992 time trends and ethnic differences in Singapore.

BACKGROUND: Non-Hodgkin's lymphoma has increased in incidence in many countries, particularly in the West. Advances in diagnostic methods and the understanding of the disease over time pose a challenge to the interpretation of these trends. The aim of this study was to determine if the disease has increased in Singapore, a newly industrialized Asian country, and to examine the possible factors that may account for any observed changes. METHODS: Data from the population-based Singapore Cancer Registry for the period 1968 to 1992 were reviewed to determine time trends based on sex and ethnic group. The Poisson regression model was fitted to the cross-tabulated data to obtain the adjusted incidence density ratios. RESULTS: A total of 1988 cases of non-Hodgkin's lymphoma were included in the analysis. There was an overall increase in incidence among both Chinese and Malaysians. However, the rate of increase was greater in females (age-standardized rate from 1.8 per 100,000 in 1968-1972 to 4.5 per 100,000 in 1988-1992) than in males (3.2 per 100,000 to 5.9 per 100,000 in the same time periods). Between ethnic groups, Malay females were at higher overall risk compared with their Chinese counterparts (incidence density ratio 1.32; 95% confidence interval, 1.08-1.61). Although a substantial proportion of patients diagnosed with Hodgkin's disease between 1968 and 1972 were reclassified on review, using present criteria, as having non-Hodgkin's lymphoma, it is unlikely that this, and other recent changes in histologic interpretation, could have accounted for an increase of this magnitude. CONCLUSIONS: Non-Hodgkin's lymphoma has increased in incidence among the Chinese and Malay populations in Singapore. The pattern of increase differs from that of the common cancer sites, and suggests the need to look for environmental and genetic factors that have not yet been elucidated.

China↗

Breast cancer in Singapore: trends in incidence 1968-1992.

BACKGROUND: Breast cancer is the most commonly occurring cancer among women in Singapore, a country which has experienced significant changes in lifestyle over the past three decades. The increase in incidence of the disease is a matter of some concern. METHODS: Data from the population-based Singapore Cancer Registry for 1968-1992 were used to determine time trends, inter-ethnic differences and the contributions of age, period and cohort effects to the incidence of the disease. RESULTS: Our results revealed an average annual increase of 3.6% over the 25-year period for all women, form 20.2 per 100,000 women in the period 1968-1972 to 38.8 per 100,000 in 1988-1992. There was a statistically significant difference between the three major ethnic groups, the rate of increase being highest in Malays (4.4%) and lowest in Indians (1.4%). The overall increase was attributable to a strong cohort effect that remained significant when adjusted for time period for Chinese women and for all ethnic groups combined. The risk was observed to increase in successive birth cohorts from the 1890s to 1960s. CONCLUSIONS: Our results suggest that breast cancer incidence rates are likely to continue to increase more sharply in the future as women born after the mid-20th century reach the high-risk age groups. They also suggest the pattern by which important aetiological factors for the disease in our population have exerted their effects, and provide support for the role of demographic and lifestyle changes as possible risk factors.

Adult↗

Comparison of upright inspiratory and expiratory chest radiographs for detecting pneumothoraces.

OBJECTIVE: Expiratory films are regarded as being superior to inspiratory films for pneumothorax detection, yet this has not been proved. In the current study, we compared inspiratory versus expiratory chest radiographs for pneumothorax detection. MATERIALS AND METHODS: Eighty-five paired inspiratory and expiratory radiographs with pneumothoraces and 93 pairs without pneumothoraces were randomly arranged and reviewed independently by three radiologists. A score of 1-5 was assigned for each hemithorax (5 = definite pneumothorax, 1 = definitely no pneumothorax). Results were compared for inspiration and expiration using receiver operating characteristic (ROC) analysis. RESULTS: The average area under the ROC curves for all readers was .973 for inspiration and .972 for expiration (nonsignificant). McNemar's test and an alpha level of .05 also yielded no significant difference in sensitivity and specificity. Four of the 85 cases were scored as definite pneumothorax on inspiration and as definitely not on expiration by all readers, and three of the 85 cases were scored as definite pneumothorax on expiration and as definitely not on inspiration. CONCLUSION: Inspiratory and expiratory upright films are equally sensitive for pneumothorax detection. Given the limitations of expiratory films, inspiratory films are recommended as the initial examination of choice for pneumothorax detection.

Female↗