Allergy in Hong Kong: an unmet need in service provision and training.

Many children in Hong Kong have allergic diseases and epidemiological data support a rising trend. Only a minority of children will grow out of their allergic diseases, so the heavy clinical burden will persist into adulthood. In an otherwise high-quality health care landscape in Hong Kong, allergy services and training are a seriously unmet need. There is one allergy specialist for 1.5 million people, which is low not only compared with international figures, but also compared with most other specialties in Hong Kong. The ratio of paediatric and adult allergists per person is around 1:460 000 and 1:2.8 million, respectively, so there is a severe lack of adult allergists, while the paediatric allergists only spend a fraction of their time working with allergy. There are no allergists and no dedicated allergy services in adult medicine in public hospitals. Laboratory support for allergy and immunology is not comprehensive and there is only one laboratory in the public sector supervised by accredited immunologists. These findings clearly have profound implications for the profession and the community of Hong Kong and should be remedied without delay. Key recommendations are proposed that could help bridge the gaps, including the creation of two new pilot allergy centres in a hub-and-spoke model in the public sector. This could require recruitment of specialists from overseas to develop the process if there are no accredited allergy specialists in Hong Kong who could fulfil this role.

Cooking fuels and prevalence of asthma: a global analysis of phase three of the International Study of Asthma and Allergies in Childhood (ISAAC).

BACKGROUND: Indoor air pollution from a range of household cooking fuels has been implicated in the development and exacerbation of respiratory diseases. In both rich and poor countries, the effects of cooking fuels on asthma and allergies in childhood are unclear. We investigated the association between asthma and the use of a range of cooking fuels around the world. METHODS: For phase three of the International Study of Asthma and Allergies in Childhood (ISAAC), written questionnaires were self-completed at school by secondary school students aged 13-14 years, 244,734 (78%) of whom were then shown a video questionnaire on wheezing symptoms. Parents of children aged 6-7 years completed the written questionnaire at home. We investigated the association between types of cooking fuels and symptoms of asthma using logistic regression. Adjustments were made for sex, region of the world, language, gross national income, maternal education, parental smoking, and six other subject-specific covariates. The ISAAC study is now closed, but researchers can continue to use the instruments for further research. FINDINGS: Data were collected between 1999 and 2004. 512,707 primary and secondary school children from 108 centres in 47 countries were included in the analysis. The use of an open fire for cooking was associated with an increased risk of symptoms of asthma and reported asthma in both children aged 6-7 years (odds ratio [OR] for wheeze in the past year, 1·78, 95% CI 1·51-2·10) and those aged 13-14 years (OR 1·20, 95% CI 1·06-1·37). In the final multivariate analyses, ORs for wheeze in the past year and the use of solely an open fire for cooking were 2·17 (95% CI 1·64-2·87) for children aged 6-7 years and 1·35 (1·11-1·64) for children aged 13-14 years. Odds ratios for wheeze in the past year and the use of open fire in combination with other fuels for cooking were 1·51 (1·25-1·81 for children aged 6-7 years and 1·35 (1·15-1·58) for those aged 13-14 years. In both age groups, we detected no evidence of an association between the use of gas as a cooking fuel and either asthma symptoms or asthma diagnosis. INTERPRETATION: The use of open fires for cooking is associated with an increased risk of symptoms of asthma and of asthma diagnosis in children. Because a large percentage of the world population uses open fires for cooking, this method of cooking might be an important modifiable risk factor if the association is proven to be causal. FUNDING: BUPA Foundation, the Auckland Medical Research Foundation, the Health Research Council of New Zealand, the Asthma and Respiratory Foundation of New Zealand, the Child Health Research Foundation, the Hawke's Bay Medical Research Foundation, the Waikato Medical Research Foundation, Glaxo Wellcome New Zealand, the NZ Lottery Board, Astra Zeneca New Zealand, Hong Kong Research Grant Council, Glaxo Wellcome International Medical Affairs.

Primary care physician perceptions on the diagnosis and management of chronic obstructive pulmonary disease in diverse regions of the world.

Chronic obstructive pulmonary disease (COPD) is a multicomponent disorder that leads to substantial disability, impaired quality of life, and increased mortality. Although the majority of COPD patients are first diagnosed and treated in primary care practices, there is comparatively little information on the management of COPD patients in primary care. A web-based pilot survey was conducted to evaluate the primary care physician's, or general practitioner's (GP's), knowledge, understanding, and management of COPD in twelve territories across the Asia-Pacific region, Africa, eastern Europe, and Latin America, using a 10-minute questionnaire comprising 20 questions and translated into the native language of each participating territory. The questionnaire was administered to a total of 600 GPs (50 from each territory) involved in the management of COPD patients and all data were collated and analyzed by an independent health care research consultant. This survey demonstrated that the GPs' understanding of COPD was variable across the territories, with large numbers of GPs having very limited knowledge of COPD and its management. A consistent finding across all territories was the underutilization of spirometry (median 26%; range 10%-48%) and reliance on X-rays (median 14%; range 5%-22%) for COPD diagnosis, whereas overuse of blood tests (unspecified) was particularly high in Russia and South Africa. Similarly, there was considerable underrecognition of the importance of exacerbation history as an important factor of COPD and its initial management in most territories (median 4%; range 0%-22%). Management of COPD was well below guideline-recommended levels in most of the regions investigated. The findings of this survey suggest there is a need for more ongoing education and information, specifically directed towards GPs outside of Europe and North America, and that global COPD guidelines appear to have limited reach and application in most of the areas studied.

Evaluation of the asthma control test: a reliable determinant of disease stability and a predictor of future exacerbations.

BACKGROUND AND OBJECTIVE: This study assessed the asthma control test (ACT) cut-off values for asthma control according to the Global Initiative for Asthma guideline in adults and the effectiveness of ACT scores in predicting exacerbations and serial changes in ACT scores over time in relation to treatment decisions. METHODS: Subjects completed ACT together with same-day spirometry and fractional concentration of exhaled nitric oxide (FeNO) measurement at baseline and at 3 months. Physicians, blinded to the ACT scores and FeNO values, assessed the patient's asthma control in the past month and adjusted the asthma medications according to management guidelines. Asthma exacerbations and urgent health-care utilization (HCU) at 6 months were recorded. RESULTS: Three hundred seventy-nine (120 men) asthmatics completed the study. The ACT cut-off for uncontrolled and partly controlled asthma were ≤19 (sensitivity 0.74, specificity 0.67, % correctly classified 69.5) and ≤22, respectively (sensitivity 0.73, specificity 0.71, % correctly classified 72.1). Baseline ACT score had an odds ratio of 2.34 (95% confidence interval: 1.48-3.69) and 2.66 (1.70-4.18) for urgent HCU and exacerbations, respectively, at 6 months (P < 0.0001). However, baseline FeNO and spirometry values had no association with urgent HCU and exacerbations. The 3-month ACT score of ≤20 correlated best with step-up of asthma medications (sensitivity 0.65, specificity 0.81, % correctly classified 72.8). For serial changes of ACT scores over 3 months, the cut-off value was best at ≤3 for treatment decisions with low sensitivity (0.23) and % correctly classified (57.3%) values. CONCLUSIONS: Single measurement of ACT is useful for assessing asthma control, prediction of exacerbation and changes in treatment decisions.

Nasal allergies in the Asian-Pacific population: results from the Allergies in Asia-Pacific Survey.

BACKGROUND: The Allergies in Asia-Pacific Survey describes the symptoms, impact, and treatment of allergic rhinitis (AR) across Australia, China, Hong Kong, Malaysia, Singapore, Taiwan, Vietnam, and the Philippines. The Allergies in Asia-Pacific Survey was undertaken to further clarify the prevalence of physician-diagnosed nasal allergies (NAs), impact on quality-of-life (QOL), existing treatment paradigms and gaps, and NA medications currently used in treatment. METHODS: Thirty-three thousand three hundred seventy-eight households were screened for individuals, ≥ 4 years old, with a physician diagnosis of AR or NA and either symptoms or treatment in the past 12 months. Standardized questionnaires were used to make comparisons across regions. A total of 1043 adults and 192 children were included in the survey. RESULTS: Nine percent of participants were diagnosed with AR with two of three responding that their NAs were seasonal in nature. Nasal congestion was the most common and bothersome symptom of AR. Most participants reported that AR impacted their QOL with nearly one-half citing impairments in school/work performance/productivity. Sleep disturbances, secondary to AR, were also shown to be appreciable. Two-thirds of patients took medication for their AR. Less than one-quarter of survey respondents reported taking an intranasal corticosteroid and the satisfaction rate was similar to that of over-the-counter medications. The most common reasons cited for dissatisfaction were related to inadequate efficacy and bothersome side effects. CONCLUSION: AR appears to be extremely common across Asia-Pacific nations. Many individuals with AR suffer from symptoms that reduce QOL and treatment gaps exist with current therapies. Through identification of disease impact and highlighting treatment gaps, clinicians may better understand and treat AR, leading to improvements in overall patient satisfaction and QOL.

Relationship between asthma control status, the Asthma Control Test™ and urgent health-care utilization in Asia.

BACKGROUND AND OBJECTIVE: Accurate assessment of control is an integral part of asthma management. We investigated the relationship between control status derived from the Global Initiative for Asthma (GINA), the Asthma Control Test (ACT) and urgent health-care utilization. METHODS: Asthma Insights and Reality in Asia-Pacific Phase 2 (AIRIAP 2) was a cross-sectional, community-based survey of 4805 subjects with asthma from urban centres across Asia. A symptom control index was derived from the AIRIAP 2 questionnaire using the GINA control criteria for day- and night-time symptoms, need for rescue medication, activity limitation and exacerbations; lung function was excluded. The main outcomes were asthma control, based on these GINA criteria and the ACT, and the relationship between control and self-reported urgent health-care utilization (hospitalization, emergency room visits or other unscheduled urgent visits) related to asthma over the previous 12months. RESULTS: Each of the symptom criteria was significantly associated with urgent health-care utilization, with odds ratios (ORs) ranging from 2.25 (95% confidence interval (CI): 1.94-2.61) for daytime symptoms to 2.57 (95% CI: 2.29-2.90) for nocturnal awakening. Similarly, control status was significantly associated with urgent health-care utilization, with ORs of 0.19 (95% CI: 0.13-0.28), 0.70 (95% CI: 0.65-0.76) and 1.00 for controlled, partly controlled and uncontrolled, respectively. The optimal ACT cut-off score for identifying uncontrolled asthma was ≤19 for subjects aged ≥12years. Urgent health-care utilization was reported by 57.2% versus 28.7% of patients scoring ≤19 versus >19 (P<0.001). CONCLUSIONS: The GINA control classification and the ACT are valid symptom-based measures that are significantly associated with urgent health-care utilization.

Acetaminophen use and risk of asthma, rhinoconjunctivitis, and eczema in adolescents: International Study of Asthma and Allergies in Childhood Phase Three.

RATIONALE: There is epidemiological evidence that the use of acetaminophen may increase the risk of developing asthma. OBJECTIVES: To investigate the risk of asthma and other allergic disorders associated with the current use of acetaminophen in 13- to 14-year-old children in different populations worldwide. METHODS: As part of the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Three, 13- to 14-year-old children completed written and video questionnaires obtaining data on current symptoms of asthma, rhinoconjunctivitis, and eczema, and a written environmental questionnaire obtaining data on putative risk factors, including acetaminophen use in the past 12 months. MEASUREMENTS AND MAIN RESULTS: The primary outcome measure was the odds ratio (OR) of current asthma symptoms associated with acetaminophen use calculated by logistic regression. A total of 322,959 adolescent children from 113 centers in 50 countries participated. In the multivariate analyses the recent use of acetaminophen was associated with an exposure-dependent increased risk of current asthma symptoms (OR, 1.43 [95% confidence interval, 1.33-1.53] and 2.51 [95% confidence interval, 2.33-2.70] for medium and high versus no use, respectively). Acetaminophen use was also associated with an exposure-dependent increased risk of current symptoms of rhinoconjunctivitis and eczema. CONCLUSIONS: Acetaminophen use may represent an important risk factor for the development and/or maintenance of asthma, rhinoconjunctivitis, and eczema in adolescent children.

Nasal allergies in the Asian-Pacific population: Results from the Allergies in Asia-Pacific Survey.

BACKGROUND: The Allergies in Asia-Pacific Survey describes the symptoms, impact, and treatment of allergic rhinitis (AR) across Australia, China, Hong Kong, Malaysia, Singapore, Taiwan, Vietnam, and the Philippines. The Allergies in Asia-Pacific Survey was undertaken to further clarify the prevalence of physician-diagnosed nasal allergies (NAs), impact on quality-of-life (QOL), existing treatment paradigms and gaps, and NA medications currently used in treatment. METHODS: Thirty-three thousand three hundred seventy-eight households were screened for individuals, ≥4 years old, with a physician diagnosis of AR or NA and either symptoms or treatment in the past 12 months. Standardized questionnaires were used to make comparisons across regions. A total of 1043 adults and 192 children were included in the survey. RESULTS: Nine percent of participants were diagnosed with AR with two of three responding that their NAs were seasonal in nature. Nasal congestion was the most common and bothersome symptom of AR. Most participants reported that AR impacted their QOL with nearly one-half citing impairments in school/work performance/productivity. Sleep disturbances, secondary to AR, were also shown to be appreciable. Two-thirds of patients took medication for their AR. Less than one-quarter of survey respondents reported taking an intranasal corticosteroid and the satisfaction rate was similar to that of over-the-counter medications. The most common reasons cited for dissatisfaction were related to inadequate efficacy and bothersome side effects. CONCLUSION: AR appears to be extremely common across Asia-Pacific nations. Many individuals with AR suffer from symptoms that reduce QOL and treatment gaps exist with current therapies. Through identification of disease impact and highlighting treatment gaps, clinicians may better understand and treat AR, leading to improvements in overall patient satisfaction and QOL.

Which population level environmental factors are associated with asthma, rhinoconjunctivitis and eczema? Review of the ecological analyses of ISAAC Phase One.

The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One showed large worldwide variations in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema, up to 10 to 20 fold between countries. Ecological analyses were undertaken with ISAAC Phase One data to explore factors that may have contributed to these variations, and are summarised and reviewed here.In ISAAC Phase One the prevalence of symptoms in the past 12 months of asthma, rhinoconjunctivitis and eczema were estimated from studies in 463,801 children aged 13 - 14 years in 155 centres in 56 countries, and in 257,800 children aged 6-7 years in 91 centres in 38 countries. Ecological analyses were undertaken between symptom prevalence and the following: Gross National Product per capita (GNP), food intake, immunisation rates, tuberculosis notifications, climatic factors, tobacco consumption, pollen, antibiotic sales, paracetamol sales, and outdoor air pollution.Symptom prevalence of all three conditions was positively associated with GNP, trans fatty acids, paracetamol, and women smoking, and inversely associated with food of plant origin, pollen, immunisations, tuberculosis notifications, air pollution, and men smoking. The magnitude of these associations was small, but consistent in direction between conditions. There were mixed associations of climate and antibiotic sales with symptom prevalence.The potential causality of these associations warrant further investigation. Factors which prevent the development of these conditions, or where there is an absence of a positive correlation at a population level may be as important from the policy viewpoint as a focus on the positive risk factors. Interventions based on small associations may have the potential for a large public health benefit.

Ambient particulate pollution and the world-wide prevalence of asthma, rhinoconjunctivitis and eczema in children: Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC).

OBJECTIVES: To investigate the effect of ambient particulate matter on variation in childhood prevalence of asthma, rhinoconjunctivitis and eczema. METHODS: Prevalences of asthma, rhinoconjunctivitis and eczema obtained in Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC) were matched with city-level estimates of residential PM(10) obtained from a World Bank model. Associations were investigated using binomial regression adjusting for GNP per capita and for clustering within country. For countries with more than one centre, a two stage meta-analysis was carried out. The results were compared with a meta-analysis of published multi-centre studies. RESULTS: Annual concentrations of PM(10) at city level were obtained for 105 ISAAC centres in 51 countries. After controlling for GNP per capita, there was a weak negative association between PM(10) and various outcomes. For severe wheeze in 13-14-year-olds, the OR for a 10 microg/m(3) increase in PM(10) was 0.92 (95% CI 0.84 to 1.00). In 24 countries with more than one centre, most summary estimates for within-country associations were weakly positive. For severe wheeze in 13-14-year-olds, the summary OR for a 10 microg/m(3) increase in PM(10) was 1.01 (0.92 to 1.10). This result was close to a summary OR of 0.99 (0.91 to 1.06) obtained from published multi-centre studies. CONCLUSIONS: Modelled estimates of particulate matter at city level are imprecise and incomplete estimates of personal exposure to ambient air pollutants. Nevertheless, our results together with those of previous multi-centre studies, suggest that urban background PM(10) has little or no association with the prevalence of childhood asthma, rhinoconjunctivitis or eczema either within or between countries.

Predicting changes in clinical status of young asthmatics: clinical scores or objective parameters?

Preventing asthma exacerbation is an important goal of asthma management. The existing clinical tools are not good in predicting asthma exacerbations in young children. Childhood Asthma Control Test (C-ACT) was recently published to be a simple tool for assessing disease control in young children. This study investigated C-ACT and other disease-related factors for indicating longitudinal changes in asthma status and predicting asthma exacerbations. During the same clinic visit, asthma patients aged 4-11 years completed the Chinese version of C-ACT and underwent exhaled nitric oxide and spirometric measurements. Blinded to these results, the same investigator assigned Disease Severity Score (DSS) and rated asthma control according to Global Initiative for Asthma. Asthma exacerbations during the next 6 months were recorded. Ninety-seven patients were recruited, with their mean (standard deviation [SD]) age being 9.2 (2.0) years. Thirty-six (37.1%) patients had uncontrolled asthma at baseline. C-ACT, DSS, and FEV(1) differed among patients with different control status (P < 0.001 for C-ACT and DSS; P = 0.028 for FEV(1)). Thirty-two patients had asthma exacerbations during the 6-month follow-up. Changes in patients' C-ACT scores correlated with changes in asthma control status, DSS, and FEV(1) (P = 0.019, 0.034, and 0.020, respectively). C-ACT score was lower among patients with asthma exacerbations (mean [SD]: 22.9 [4.2] vs. 24.5 [2.1]; P = 0.015). Logistic regression confirmed that the occurrence of asthma exacerbations was associated only with baseline C-ACT (B = -0.203, P = 0.042). In conclusion, C-ACT is better than DSS and objective parameters in reflecting changes in asthma status and predicting asthma exacerbations in young children.

Asthma Control Test correlates well with the treatment decisions made by asthma specialists.

BACKGROUND AND OBJECTIVE: Poor assessment of asthma control results in suboptimal treatment. Identifying parameters that accurately assess control will benefit treatment decisions. The Asthma Control Test (ACT) is a five-item questionnaire for the assessment of asthma control. This study evaluated its correlation with the treatment decisions made by asthma specialists in an outpatient clinic setting, and compared its performance with other conventional parameters including spirometry, PEF rate (PEFR), fractional exhaled nitric oxide (FeNO) and BHR. METHODS: The 383 (122 men) study subjects completed a 1-month diary on symptoms and PEFR before the assessment. All subjects then completed the ACT together with same-day spirometry and FeNO measurement. BHR to methacholine was performed in 73 subjects in the week before assessment. Asthma specialists, blinded to the results of the ACT, FeNO and BHR (but not spirometry and PEFR), assessed the patients' level of control according to the 2006 version of the Global Initiative for Asthma guidelines and made appropriate treatment decision. RESULTS: The group mean (SD) age was 46.1 (13.4) years with pre-bronchodilator FEV(1) 84.72 (20.81) % predicted. Receiver operating characteristic (ROC) curve analysis found that an ACT score of < or = 20 best correlated with uncontrolled asthma (area under curve (AUC) = 0.76) with a sensitivity of 70.5%, specificity 76.0%, positive predictive value 76.2% and negative predictive value 70.2% for predicting step-up of asthma therapy. On ROC analysis, the ACT score had the highest AUC (0.81 (P < 0.001)) for changing asthma therapy when compared with FeNO, spirometry, PEFR and BHR parameters CONCLUSIONS: The ACT correlated better with treatment decisions made by asthma specialists than spirometry, PEFR and FeNO.

Self-reported truck traffic on the street of residence and symptoms of asthma and allergic disease: a global relationship in ISAAC phase 3.

BACKGROUND: Associations between traffic pollution on the street of residence and a range of respiratory and allergic outcomes in children have been reported in developed countries, but little is known about such associations in developing countries. METHODS: The third phase of the International Study of Asthma and Allergies in Childhood (ISAAC) was carried out in 13- to 14-year-old and 6- to 7-year-old children across the world. A question about frequency of truck traffic on the street of residence was included in an additional questionnaire. We investigated the association between self-reported truck traffic on the street of residence and symptoms of asthma, rhinoconjunctivitis, and eczema with logistic regression. Adjustments were made for sex, region of the world, language, gross national income, and 10 other subject-specific covariates. RESULTS: Frequency of truck traffic on the street of residence was positively associated with the prevalence of symptoms of asthma, rhinoconjunctivitis, and eczema with an exposure-response relationship. Odds ratios (95% confidence intervals) for "current wheeze" and "almost the whole day" versus "never" truck traffic were 1.35 (1.23-1.49) for 13- to 14-year-olds and 1.35 (1.22-1.48) for 6- to 7-year-olds. CONCLUSIONS: Higher exposure to self-reported truck traffic on the street of residence is associated with increased reports of symptoms of asthma, rhinitis, and eczema in many locations in the world. These findings require further investigation in view of increasing exposure of the world's children to traffic.

Prevalence of asthma among Chinese adolescents living in Canada and in China.

BACKGROUND: Studies of the prevalence of asthma among migrating populations may help in identifying environmental risk factors. METHODS: We analyzed data from Vancouver, Canada, and from Guangzhou, Beijing and Hong Kong, China, collected during phase 3 of the International Study of Asthma and Allergies in Childhood. We subdivided the Vancouver adolescents according to whether they were Chinese immigrants to Canada, Canadian-born Chinese or Canadian-born non-Chinese. We compared the prevalence of asthma and wheezing among Chinese adolescents born in Canada, Chinese adolescents who had immigrated to Canada and Chinese adolescents living in China. RESULTS: Of 7794 Chinese adolescents who met the inclusion criteria, 3058 were from Guangzhou, 2824 were from Beijing, and 1912 were from Hong Kong. Of 2235 adolescents in Vancouver, Canada, 475 were Chinese immigrants, 617 were Canadian-born Chinese, and 1143 were Canadian-born non-Chinese. The prevalence of current wheezing among boys ranged from 5.9% in Guangzhou to 11.2% in Canadian-born Chinese adolescents. For girls, the range was 4.3% in Guangzhou to 9.8% in Canadian-born Chinese adolescents. The prevalence of ever having had asthma ranged from 6.6% to 16.6% for boys and from 2.9% to 15.0% for girls. Prevalence gradients persisted after adjustment for other environmental variables (odds ratios for ever having had asthma among Canadian-born Chinese compared with native Chinese in Guangzhou: 2.72 [95% confidence interval 1.75-4.23] for boys and 5.50 [95% confidence interval 3.21-9.44] for girls; p < 0.001 for both). Among Chinese adolescents living in Vancouver, the prevalence of ever wheezing increased with duration of residence, from 14.5% among those living in Canada for less than 7 years to 20.9% among those living their entire life in Canada. The same pattern was observed for the prevalence of ever having had asthma, from 7.7% to 15.9%. INTERPRETATION: Asthma symptoms in Chinese adolescents were lowest among residents of mainland China, were greater for those in Hong Kong and those who had immigrated to Canada, and were highest among those born in Canada. These findings suggest that environmental factors and duration of exposure influence asthma prevalence.

The burden of lung disease in Hong Kong: a report from the Hong Kong Thoracic Society.

BACKGROUND AND OBJECTIVE: The burden of lung disease in Hong Kong is not known. This study determined the mortality and hospitalization rates of respiratory diseases in Hong Kong in 2005, their trend in the past decade and their incidence/prevalence. METHODS: Mortality data were obtained from the Department of Health and hospitalization data from the Hospital Authority, Hong Kong. Incidence/prevalence data were obtained from local registries or local studies. Trends of mortality and hospitalization rates of various respiratory diseases from 1997 and 2005 were calculated after age standardization and were tested for significance using negative binomial regression analysis. Age standardized mortality rates in Hong Kong were compared with those of the UK and globally. RESULTS: Respiratory disease was the most common cause of mortality and hospitalization in Hong Kong in 2005. Globally and in the UK, cardiovascular disease ranked first in mortality. Respiratory infections ranked first in respiratory mortality, followed by respiratory tract cancer and chronic obstructive lung disease. Respiratory infections also ranked first followed by chronic obstructive lung disease in the utilization of respiratory inpatient bed-days. While mortality rates from all respiratory diseases decreased in the past decade, hospitalization rates remained unchanged. Unlike other respiratory diseases, mortality from respiratory infections have increased since 2001. Smoking is the most important risk factor in non-communicable respiratory diseases. CONCLUSIONS: Respiratory disease is responsible for the highest health-care burden locally. Increased efforts in improving management and prevention of these diseases, including tobacco control, improving air quality and vaccination against influenza and pneumococci, are necessary.

Association between paracetamol use in infancy and childhood, and risk of asthma, rhinoconjunctivitis, and eczema in children aged 6-7 years: analysis from Phase Three of the ISAAC programme.

BACKGROUND: Exposure to paracetamol during intrauterine life, childhood, and adult life may increase the risk of developing asthma. We studied 6-7-year-old children from Phase Three of the International Study of Asthma and Allergies in Childhood (ISAAC) programme to investigate the association between paracetamol consumption and asthma. METHODS: As part of Phase Three of ISAAC, parents or guardians of children aged 6-7 years completed written questionnaires about symptoms of asthma, rhinoconjunctivitis, and eczema, and several risk factors, including the use of paracetamol for fever in the child's first year of life and the frequency of paracetamol use in the past 12 months. The primary outcome variable was the odds ratio (OR) of asthma symptoms in these children associated with the use of paracetamol for fever in the first year of life, as calculated by logistic regression. FINDINGS: 205 487 children aged 6-7 years from 73 centres in 31 countries were included in the analysis. In the multivariate analyses, use of paracetamol for fever in the first year of life was associated with an increased risk of asthma symptoms when aged 6-7 years (OR 1.46 [95% CI 1.36-1.56]). Current use of paracetamol was associated with a dose-dependent increased risk of asthma symptoms (1.61 [1.46-1.77] and 3.23 [2.91-3.60] for medium and high use vs no use, respectively). Use of paracetamol was similarly associated with the risk of severe asthma symptoms, with population-attributable risks between 22% and 38%. Paracetamol use, both in the first year of life and in children aged 6-7 years, was also associated with an increased risk of symptoms of rhinoconjunctivitis and eczema. INTERPRETATION: Use of paracetamol in the first year of life and in later childhood, is associated with risk of asthma, rhinoconjunctivitis, and eczema at age 6 to 7 years. We suggest that exposure to paracetamol might be a risk factor for the development of asthma in childhood.

Temporal relationship between air pollutants and hospital admissions for chronic obstructive pulmonary disease in Hong Kong.

AIMS: To assess any relationship between the levels of ambient air pollutants and hospital admissions for chronic obstructive pulmonary disease (COPD) in Hong Kong. METHODS: A retrospective ecological study was undertaken. Data of daily emergency hospital admissions to 15 major hospitals in Hong Kong for COPD and indices of air pollutants (sulphur dioxide (SO(2)), nitrogen dioxide (NO(2)), ozone (O(3)), particulates with an aerodynamic diameter of <10 microm (PM(10)) and 2.5 microm (PM(2.5))) and meteorological variables from January 2000 to December 2004 were obtained from several government departments. Analysis was performed using generalised additive models with Poisson distribution, adjusted for the effects of time trend, season, other cyclical factors, temperature and humidity. Autocorrelation and overdispersion were corrected. RESULTS: Significant associations were found between hospital admissions for COPD with all five air pollutants. Relative risks for admission for every 10 microg/m(3) increase in SO(2), NO(2), O(3), PM(10) and PM(2.5) were 1.007, 1.026, 1.034, 1.024 and 1.031, respectively, at a lag day ranging from lag 0 to cumulative lag 0-5. In a multipollutant model, O(3), SO(2) and PM(2.5) were significantly associated with increased admissions for COPD. SO(2), NO(2) and O(3) had a greater effect on COPD admissions in the cold season (December to March) than during the warm season. CONCLUSION: Ambient concentrations of air pollutants have an adverse effect on hospital admissions for COPD in Hong Kong, especially during the winter season. This might be due to indoor exposure to outdoor pollution through open windows as central heating is not required in the mild winter. Measures to improve air quality are urgently needed.

Sleep-disordered breathing and continuous positive airway pressure compliance in a group of commercial bus drivers in Hong Kong.

OBJECTIVE AND BACKGROUND: Sleep-disordered breathing may predispose drivers to road traffic accidents. However, CPAP acceptance and compliance among commercial bus drivers is unknown. METHODS: We conducted a sleep questionnaire survey at a bus depot followed by random selection of bus drivers for home sleep study with the mesam iv device. Bus drivers with a respiratory disturbance index (RDI)>or=5/h were invited to have hospital-based polysomnography for confirmation followed by nasal CPAP treatment. RESULTS: Out of 1477 bus drivers, 1016 (971 men) were interviewed with mean (SD) age of 45.3 (7.5) years, BMI 24.9 (3.6) kg/m2, neck circumference 38.9 (3.1) cm and Epworth sleepiness score 4.8 (4.0). Sleepiness at work was reported by 60.9%, snoring>or=3 nights per week 23.9%, witnessed apnoea 3.7% and having fallen asleep during driving by 24%. Among 211 who underwent home sleep study, 85 (40.3%), 55 (26.1%) and 37 (17.5%) had RDI>or=5, >or=10 and >or=15/h respectively. BMI, snoring intensity and neck circumference were the positive independent factors associated with the RDI. Of the 25 drivers who attended polysomnography, nine accepted CPAP prescription with improvement of Epworth sleepiness score, trail B and digit span after 3 months with CPAP usage of 4.5 (1.3) h/night. CONCLUSION: The estimated minimum prevalence rates of sleep-disordered breathing and obstructive sleep apnoea syndrome were 8.4% and 5.4% respectively among the bus drivers. Home CPAP acceptance was low among bus drivers with sleep apnoea but there was significant improvement of subjective sleepiness and cognitive function among those on CPAP treatment.

Worldwide time trends in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and eczema in childhood: ISAAC Phases One and Three repeat multicountry cross-sectional surveys.

BACKGROUND: Data for trends in prevalence of asthma, allergic rhinoconjunctivitis, and eczema over time are scarce. We repeated the International Study of Asthma and Allergies in Childhood (ISAAC) at least 5 years after Phase One, to examine changes in the prevalence of symptoms of these disorders. METHODS: For the ISAAC Phase Three study, between 2002 and 2003, we did a cross-sectional questionnaire survey of 193,404 children aged 6-7 years from 66 centres in 37 countries, and 304,679 children aged 13-14 years from 106 centres in 56 countries, chosen from a random sample of schools in a defined geographical area. FINDINGS: Phase Three was completed a mean of 7 years after Phase One. Most centres showed a change in prevalence of 1 or more SE for at least one disorder, with increases being twice as common as decreases, and increases being more common in the 6-7 year age-group than in the 13-14 year age-group, and at most levels of mean prevalence. An exception was asthma symptoms in the older age-group, in which decreases were more common at high prevalence. For both age-groups, more centres showed increases in all three disorders more often than showing decreases, but most centres had mixed changes. INTERPRETATION: The rise in prevalence of symptoms in many centres is concerning, but the absence of increases in prevalence of asthma symptoms for centres with existing high prevalence in the older age-group is reassuring. The divergent trends in prevalence of symptoms of allergic diseases form the basis for further research into the causes of such disorders.