Development of a data-driven COVID-19 prognostication tool to inform triage and step-down care for hospitalised patients in Hong Kong: a population-based cohort study.

BACKGROUND: This is the first study on prognostication in an entire cohort of laboratory-confirmed COVID-19 patients in the city of Hong Kong. Prognostic tool is essential in the contingency response for the next wave of outbreak. This study aims to develop prognostic models to predict COVID-19 patients' clinical outcome on day 1 and day 5 of hospital admission. METHODS: We did a retrospective analysis of a complete cohort of 1037 COVID-19 laboratory-confirmed patients in Hong Kong as of 30 April 2020, who were admitted to 16 public hospitals with their data sourced from an integrated electronic health records system. It covered demographic information, chronic disease(s) history, presenting symptoms as well as the worst clinical condition status, biomarkers' readings and Ct value of PCR tests on Day-1 and Day-5 of admission. The study subjects were randomly split into training and testing datasets in a 8:2 ratio. Extreme Gradient Boosting (XGBoost) model was used to classify the training data into three disease severity groups on Day-1 and Day-5. RESULTS: The 1037 patients had a mean age of 37.8 (SD ± 17.8), 53.8% of them were male. They were grouped under three disease outcome: 4.8% critical/serious, 46.8% stable and 48.4% satisfactory. Under the full models, 30 indicators on Day-1 and Day-5 were used to predict the patients' disease outcome and achieved an accuracy rate of 92.3% and 99.5%. With a trade-off between practical application and predictive accuracy, the full models were reduced into simpler models with seven common specific predictors, including the worst clinical condition status (4-level), age group, and five biomarkers, namely, CRP, LDH, platelet, neutrophil/lymphocyte ratio and albumin/globulin ratio. Day-1 model's accuracy rate, macro-/micro-averaged sensitivity and specificity were 91.3%, 84.9%/91.3% and 96.0%/95.7% respectively, as compared to 94.2%, 95.9%/94.2% and 97.8%/97.1% under Day-5 model. CONCLUSIONS: Both Day-1 and Day-5 models can accurately predict the disease severity. Relevant clinical management could be planned according to the predicted patients' outcome. The model is transformed into a simple online calculator to provide convenient clinical reference tools at the point of care, with an aim to inform clinical decision on triage and step-down care.

Respiratory health of road-side vendors in a large industrialized city.

GOAL, SCOPE AND BACKGROUND: The literature reports a high prevalence of respiratory symptoms associated with exposure to motor vehicle exhaust emissions and people exposed to vehicle emissions are at risk of reduced lung function and cardiovascular performance. Although the effect of traffic emissions is a known risk to respiratory health, retailers are often situated along major roads in a busy urban environment to maximise customers. Shop assistants in an air-conditioned environment should be less exposed to traffic fumes and their lung function should be better preserved compared to 'unprotected' vendors exposed directly to vehicle emissions. The lung function of these two groups of workers has not previously been compared. The aims of this study are to determine if there is a difference in the concentration of respirable particles of diameter less than 10 micrometers (PM10) inside and outside air-conditioned shops along a busy major road; and to compare the lung function parameters, blood lead levels and respiratory symptoms between road-side vendors directly 'exposed' to traffic fumes and vendors working in 'protected' air-conditioned shops along the same road. METHODS: Roadside vendors (n=33) and adjacent shop assistants (n=31) were recruited for the study in a district known to have high emissions and pollution measures. All subjects were asked to complete a questionnaire providing the frequency of their respiratory symptoms. Spirometry pulmonary function tests were conducted and exhaled carbon monoxide levels (ECO), oxygen saturation and blood lead levels (BLL) were measured. PM10 level was concurrently measured in the subject's working environment. Pulmonary function data and ECO levels collected from a cohort of university staff aged > or = 30 years (n=92) at a university campus were included for comparison. RESULTS: The concentration of particulate matter (PM10) at the roadside (210 +/- 70 microg/m3) was significantly higher than inside the shops (130 +/- 40 microg/m3). There was no difference in lung function parameters or BLL between the groups, however the forced vital capacity of both groups of vendors was significantly lower than a 'control' cohort of academic institution personnel (n=92). DISCUSSION: This study illustrated that while the level of pollution improved with air conditioning, this may not be sufficient to prevent respiratory consequences. Our data suggests that a reduction in occupational exposure is not enough to protect these workers. CONCLUSIONS: Air-conditioned work environment is insufficient to protect the respiratory system against the adverse effects of exposure to vehicle emissions. RECOMMENDATIONS: The overwhelming effect of exposure during travel to and from work and at home cannot be underestimated. More stringent guidelines to control pollution appear necessary to protect the respiratory health of both shop-keepers and road-side vendors and further studies to explore the effect on respiratory health of the exposure to pollutants associated with commuting to and from work are warranted.

Peak early diastolic mitral annulus velocity by tissue Doppler imaging adds independent and incremental prognostic value.

OBJECTIVES: The aim of this study was to ascertain if left ventricular mitral annulus velocities measured by tissue Doppler imaging (TDI) are more powerful predictors of outcome compared with clinical data and standard Doppler-echocardiographic parameters. BACKGROUND: Tissue Doppler imaging of basal or mitral annulus velocities provides rapid assessment of ventricular long axis function. But it is not known if TDI-derived velocities in systole and diastole add incremental value and are superior to the standard Doppler-echocardiographic measurements as a predictor of outcome. METHODS: The study population consisted of 518 subjects, 353 with cardiac disease and 165 normal subjects who had full Doppler two-dimensional-echocardiographic studies with measurement of mitral inflow velocities in early and late diastole, E-wave deceleration time (DT), peak systolic mitral annular velocity (Sm) early and late diastolic mitral annular velocity (Em and Am) by TDI, early diastolic flow propagation velocity, and standard chamber dimensions. All subjects were followed up for two years. The end point was cardiac death. RESULTS: Tissue Doppler imaging mitral annulus systolic and diastolic velocities were all significantly lower in the non-survivors (all p < 0.05) as was DT (p = 0.024). In the Cox model the best predictors of mortality were Em, Sm, Am, left ventricular ejection fraction, left ventricular mass, and left atrial diameter in systole (LADs). By backward stepwise analysis Em and LADs were the strongest predictors. After forcing the TDI measurements into the covariate model with clinical and mitral DT <0.16 s, Em provided significant incremental value for predicting cardiac mortality (p = 0.004). CONCLUSIONS: Mitral annulus velocity measured by TDI in early diastole gives incremental predictive power for cardiac mortality compared to clinical data and standard echocardiographic measurements. This easily available measurement adds significant value in the clinical management of cardiac patients.

Discordance between lung function of chinese university students and 20-year-old established norms.

OBJECTIVE: We examined the validity of the 20-year-old established Asian norms for pulmonary function in a contemporary cohort of Hong Kong Chinese university students. DESIGN AND PARTICIPANTS: Pulmonary function testing was conducted in university students (n = 805). SETTING: A university campus in Hong Kong. MEASUREMENTS AND RESULTS: Parameters recorded included gender, age, height, weight, standard lung function variables (ie, FEV1, FVC, and peak expiratory flow rate [PEFR]), and exhaled carbon monoxide (CO) level. Subjects completed a questionnaire on pulmonary health, smoking history, and their dietary and exercise habits within 3 months of the study. Data were compared with the established norms for lung function for Chinese persons from Hong Kong. On average, subjects were taller than those reported in the original cohort, on whom the established norms are based; however, FEV1, FVC, and PEFR were lower. As predicted, the exhaled CO level was higher in smokers. Those who exercised regularly had a higher FEV1 and FVC, and reported fewer respiratory complaints. CONCLUSIONS: Our findings support the idea that lung function norms not only differ across ethnic groups, but that they may be susceptible to change over a single generation within an ethnic group living in the same geographic region. Assuming the equivalence of our testing methods and those on which established norms are based, our findings shed further insight into the dynamic nature of lung function, and have implications regarding the definition of normal pulmonary function and its variance over the short term.

Randomized double-blind trial comparing oral paracetamol and oral nonsteroidal antiinflammatory drugs for treating pain after musculoskeletal injury.

STUDY OBJECTIVE: We investigate the efficacy and safety of oral paracetamol compared with oral nonsteroidal antiinflammatory drugs or combination therapy in relieving pain after blunt limb injury in an emergency department (ED). METHODS: This was a double-blind, randomized, controlled study in an ED of a university hospital in the New Territories of Hong Kong. Three hundred adult patients with painful isolated limb injuries were enrolled. Primary outcome measures were pain relief at rest and with limb movement, adverse events, and patient satisfaction. RESULTS: There was no statistical difference in the mean reduction in pain score between any of the combinations at any point, although combination therapy was the first to reach a clinically significant reduction in pain score (<13 mm), and diclofenac-paracetamol combinations consistently produced a greater reduction in mean pain score than either nonsteroidal antiinflammatory drugs or paracetamol alone. All combinations appeared to be safe, although more patients receiving diclofenac-paracetamol combination complained of abdominal pain. The median patient satisfaction scores were poor. CONCLUSION: In the doses, frequencies, and routes of administration used for this study, any analgesic benefit of oral paracetamol-nonsteroidal antiinflammatory drug combinations over single nonsteroidal antiinflammatory drugs or paracetamol treatment is small and of doubtful clinical significance. Nonsteroidal antiinflammatory drugs, paracetamol, and diclofenac-paracetamol combinations appeared equally safe in the management of musculoskeletal pain.

Simple aspiration as initial treatment for primary spontaneous pneumothorax: results of 91 consecutive cases.

Varying opinions exist regarding the choice of initial treatment for primary spontaneous pneumothorax (PSP). This study aims to determine the success rate of simple aspiration of PSP, identify factors associated with failure, and identify associated complications. A retrospective analysis was performed on 91 consecutive patients receiving simple aspiration for PSP at the Emergency Department of a university teaching hospital in Hong Kong, China. The overall success rate was 50.5%. Failed cases had significantly larger sizes of pneumothorax, and significantly larger volumes of air aspirated. Pneumothorax size > or =40% was significantly associated with failure. In a multivariate analysis, pneumothorax size > or =40%, compared to size 21-39%, independently predicted failure, with an odds ratio of 8.88 (95% CI, 2.49 to 31.63). Complications were rarely encountered. It is concluded that the success rate may be significantly improved by excluding patients with pneumothorax size 40% or larger from this modality of treatment.

Development of an automated model to predict the risk of elderly emergency medical admissions within a month following an index hospital visit: a Hong Kong experience.

OBJECTIVES: To develop an automated risk prediction model to identify elderly patients at high risk of emergency admission to medical wards within 28 days following an index hospital visit. METHODS: A retrospective data analysis of 41 hospitals and 48 specialist outpatient clinics in Hong Kong. The study subjects were elderly patients aged 65 years or above, who had index hospital visit(s) in the year of 2005, which included hospitalizations at medical wards and attendances at the accident and emergency departments or specialist outpatient clinics for medical conditions. Multiple logistic regression was used to estimate the risk of emergency medical admission in 28 days after an index hospital visit. Model validation was performed against the complete cohort in 2006. RESULTS: Over a million of episodes were included in the derivation cohort. A total of 14 predictor variables included patient socio-demographics, service utilization in the previous year, presence and number of chronic diseases and type of index episode. The model has a good discriminative ability with the area under receiver-operating characteristic curve at 0.819 and 0.824 for the derivation and validation cohorts, respectively. The model has a sensitivity of 70.3 per cent, specificity of 78.4 per cent, positive predictive value of 21.7 per cent and negative predictive value of 96.9 per cent. CONCLUSION: This simple, accurate and objective risk prediction model has been computerized into an automated screening tool to recruit high-risk elderly patients discharged from all public hospitals in Hong Kong into the Community Health Call Centre service with an aim to prevent avoidable hospitalizations.

Psychological correlates of physical abuse in Hong Kong Chinese adolescents.

OBJECTIVE: To understand the associations between adolescent family physical maltreatment and psychiatric morbidity or psychological problems. METHODS: questionnaire survey on 489 secondary school students in Form 2 from 10 schools in Hong Kong. Questions regarding three forms of family physical maltreatment were measured: corporal punishment within the past 6 months, beaten without any reason within the past 6 months, or ever been beaten to injury. MAIN RESULT: Corporal punishment was not associated with the psychological variables after Bonferroni adjustment was made. Those who experienced the two other forms of physical maltreatment had significant and strong associations with positive Achenbach CBCL outcome (OR from 3.26 to 3.27), drug abuse problems (OR from 2.60 to 20.38), self-injurious behaviors (OR from 3.34 to 8.47) and poor perceived parental support. In addition, those who had ever been beaten to injury scored significantly lower in the "physical appearance" and "behavioral conduct" subscales of the Harter's Self-Perception Profile for Adolescents. CONCLUSIONS: In Hong Kong, some forms of family physical maltreatment (beaten for no reason and beaten to injury) were associated with a number of psychiatric/psychological problems. Further studies should be carried out to clarify whether the relationships are causal in nature.

Predictors of positive stool culture in adult patients with acute infectious diarrhea.

Stool cultures for bacterial pathogens are often requested for investigation of patients with infectious diarrhea, but the literature reports low yield for this diagnostic test. The identification of clinical predictors of positive stool culture will help the physician in determining the necessity for stool requests. A retrospective study was performed in the setting of an Emergency Department (ED) in Hong Kong, to compare presenting features of adult patients with positive stool culture against those with negative culture. We compared 130 consecutive cases with positive stool culture, over a 12-month period, against 119 control cases obtained from a random sampling of 524 consecutive negative cases over the same period. In multivariate analysis, the independent variables found to be associated with positive stool culture were: the month of presentation (summer season), fever, duration of abdominal pain, and requirement of IV fluid therapy. Neither bloody diarrhea nor persistent diarrhea was associated with positive stool culture.

Neck pain in Hong Kong: a telephone survey on consequences and health service utilization.

STUDY DESIGN: A regionally representative telephone survey using a 2-stage randomization process. OBJECTIVE: (1) To investigate the prevalence and consequence of neck pain in terms of disability and rate of absenteeism from work. (2) To describe the health services utilization pattern of neck pain subjects and to analyse the factors associated with neck pain and health services utilization pattern. SUMMARY OF BACKGROUND DATA: There has been a lack of reliable information on the health service utilization pattern of neck pain subjects, the consequences and the patient perceived effectiveness of neck pain management in Hong Kong and Asian countries. METHODS: Subjects were interviewed on the sociodemographic characteristics, occurrence and consequences of neck pain, and the health utilization pattern. A random sample of the respondents was re-interviewed 7 to 10 days after the initial interview, by an independent interviewer for the reliability check. RESULTS: A total of 4640 subjects were interviewed. The 12-month prevalence was 64.6% (95% CI: 63.2%-66.0%). About 38.0% of these patients suffered from moderate to severe pain. Moreover, 17.7% of these subjects had to limit their social activities and 19% had to limit their work. About 25% of those subjects had consulted medical or health practitioners. Medical consultation is the majority and physiotherapy came second. Self-massage was the most preferred (83.3%) mode of self-care. Physiotherapy was regarded as the most effective health service, with 60% of the respondents' neck pain completely removed. Although most people chose self-massage to be the most effective self-care treatment, only one-third (30.2%) of them had their neck pain improved by less than a half. CONCLUSION: Neck pain is highly prevalent with an increasing impact in Hong Kong. More than one-third of neck pain patients suffered from moderate to severe pain and around 20% of them had to limit their work. About 25% of neck pain patient have consulted medical or health professionals. Physiotherapy and private medical clinic were the 2 service providers with high percentage of perceived complete improvement. There was a general trend that more neck pain patients used complementary therapies.

Work-related musculoskeletal disorders in urban bus drivers of Hong Kong.

INTRODUCTION: Work-related musculoskeletal disorders (WMSD) affect workers in many occupations including drivers of large vehicles. Urban bus drivers have been found to have high prevalence rates of back problems in overseas studies. Hong Kong is a densely populated city and has a large number of double-deck buses that constitute a major means of public transportation. The present study aimed at investigating the prevalence and characteristics of WMSD in male and female bus drivers who operate double-deck buses in Hong Kong. METHOD: Altogether 481 bus drivers (404 males, 77 females) participated in the study that consisted of a questionnaire survey as well as physical assessment. The questionnaire included questions on work, musculoskeletal complaints and perceived occupational risk factors associated with each discomfort. Physical assessment consisted of measurement of lumbar spine mobility, hand grip strength, sit-and-reach test, and observation of standing and sitting postures. RESULTS: The results showed generally the male drivers had longer years of work experience but their daily workloads were similar to the females. On the average drivers worked 9-10 h per day, with 5 days on and 1 day off. Neck, back, shoulder and knee/thigh areas had the highest 12-month prevalence rates ranging from 35% to 60%, and about 90% of the discomfort was related to bus-driving. Occupational factors of prolonged sitting and anthropometric mismatch were perceived to be most related to musculoskeletal discomfort. On physical examination, grip strength was significantly related to neck and shoulder discomfort. CONCLUSIONS: The present results showed high prevalence rates of WMSD among bus drivers in Hong Kong which warrants further investigation.

The prevalence of and risk factors for neck pain and upper limb pain among secondary school teachers in Hong Kong.

OBJECTIVE: To investigate the prevalence and occupational risk factors of neck and upper limb disorders among secondary school teachers. METHODS: One hundred secondary schools in Hong Kong were randomly chosen. Every full-time teacher received a questionnaire and a letter describing the purpose of the study. Questionnaires were collected 1 to 3 weeks later. RESULTS: Among 3,100 secondary school teachers, the lifelong prevalence of neck pain and upper limb pain was 69.3% (2091/3018) and 35.8% (1088/3042) respectively. The lifelong cumulative incidence of both neck and upper limb pain was 31.6% (938/2966). Multiple logistic regression analysis showed that gender, age and working in head down posture were identified as risk factors for neck and upper limb pain. High workload, low colleague support and high anxiety were found to be significant on affecting the neck pain and upper limb pain developed after becoming teachers. CONCLUSIONS: Neck pain and upper limb pain were highly prevalent in secondary school teachers in Hong Kong. Gender, age, head down posture and some psychological factors were found to be significant risk factors.

Effects of strength training on body composition and bone mineral content in children who are obese.

The purpose of this study was to test the hypothesis that strength training benefits diet-controlled obese children with respect to lean mass and bone mineral acquisition. Eighty-two Hong Kong school children (aged 10.4 +/- 1.0 years, 70 in Tanner stage 1, 12 in stage 2) who were obese/overweight were randomly assigned to receive either a balanced low-energy (900-1200 cal) diet plus strength training (n = 41) (training group) or the diet alone (n = 41) (control group). The training group attended a 75-minute strength exercise program 3 times/week for 6 weeks (phase 1), after which they were offered and 22 children opted to continue a once-weekly program for a further 28 weeks (phase 2). All children were evaluated at baseline, after 6 weeks, and at the end of the 36-week study (including an intervening 2-week introduction to phase 2). Body composition and bone mineral content were measured by dual-energy X-ray absorptiometry, and diet was assessed by food-frequency questionnaire. The results showed that the exercise programs were well accepted, with good attendance at the exercise classes. After 6 weeks, the children in the training group showed significantly larger increases in lean body mass (+ 0.8 kg [2.4%] vs. +0.3 kg [1.0%], p < 0.05) and total bone mineral content (+46.9 g [3.9%] vs. +33.6 g [2.9%], p < 0.05) than those in the control group. At the end of the study, these trends were maintained in the continued-training subgroup, though no longer reaching statistical significance. We conclude that in diet-controlled prepubertal obese/overweight children, participation in an exercise program with emphasis on strength training resulted in improved lean mass and bone mineral accrual.

Comparison of thoracic ultrasound, clinical acumen, and radiography in patients with minor chest injury.

BACKGROUND: This study was designed to compare ultrasonography, clinical findings, and radiography in the detection of rib and sternal fractures. METHODS: In a prospective study, 88 patients presenting consecutively to an emergency department with isolated blunt chest injury of mild to moderate force were recruited. RESULTS: Ultrasonography yielded a sensitivity of 80.3 (95% confidence interval [CI], 69.5-88.5) for detecting chest wall fractures compared with sensitivities of 26.0 (95% CI, 15.8-36.3) for clinical acumen and 23.7 (95% CI, 14.7-34.8) for radiography. CONCLUSION: Early ultrasonography is more accurate than clinical and radiologic evaluation at detecting rib and sternal fractures.

Correlation between color power Doppler sonographic measurement of breast tumor vasculature and immunohistochemical analysis of microvessel density for the quantitation of angiogenesis.

OBJECTIVE: To record the correlation between color power Doppler sonographic measurement of breast tumor vasculature and immunohistochemical analysis of microvessel density for the quantitation of angiogenesis. METHODS: Women with palpable breast masses scheduled for excision biopsy were scanned with two- and three-dimensional color power Doppler sonography before and after the administration of a sonographic contrast agent. Vessel counts were performed on two- and three-dimensional sonographic images before and after contrast agent administration. All tumors were surgically removed and underwent immunohistochemical analysis for microvessel density assessment. The sonographic measure of tumor vascularity was correlated with microvessel density. RESULTS: Pathologic examination showed 43 breast cancers and 14 benign breast masses. Higher microvessel density was noted in malignant than benign breast masses (P < .0005). Color power Doppler sonographic measurement of tumor vessel number showed a significant positive correlation with tumor size (P < .05) and progesterone receptor negativity (P < .05). A significant positive correlation was observed between microvessel density and the number of intratumoral blood vessels assessed by both two- and three-dimensional color power Doppler sonography (P < .05). Regression models showed three-dimensional color power Doppler sonography to have a significantly higher correlation with microvessel density when compared with two-dimensional color power Doppler sonography at baseline (P < .005). The administration of a sonographic contrast agent did not improve correlation with microvessel density. CONCLUSIONS: A significant correlation was shown between color power Doppler sonographic measurement of tumor vascularity and microvessel density by immunohistochemical analysis. Further improvement in Doppler sonographic techniques to map capillary vessel flow should be explored to improve the current association with pathologic findings.

Accuracy of clinical diagnostic methods of threatened abortion.

OBJECTIVE: To examine the accuracy of clinical diagnostic methods in assessing vaginal bleeding in pregnant women before 28 weeks' gestation. METHODS: 772 consecutive women who presented with threatened abortion before 28 weeks' gestation were studied. Structured history and physical examination were performed on each woman as initial clinical assessment. This was followed by transvaginal sonography to determine the status of pregnancy. The accuracy of diagnoses at different clinical stages (history, physical examination, and transvaginal sonography) relative to the final diagnosis was compared using the kappa coefficient (kappa). RESULTS: Clinicians were unable to accurately diagnose or predict the status of the pregnancy from history alone (kappa = 0.33; 95% CI 0.28, 0.38) or after physical examination (kappa = 0.57; 95% CI 0.52, 0.62). Transvaginal sonography led to an accurate diagnosis of pregnancy status (kappa = 0.96; 95% CI 0.95, 0.98) in most cases, except where an ectopic pregnancy existed. Absence of abdominal tenderness (p = 0.04), cervical excitation (p = 0.02), and incorrect identification of retained products of conception on transvaginal sonography (p = 0.01) were features of missed ectopic pregnancy. CONCLUSIONS: The clinical assessment of threatened abortion by history and physical examination is unreliable in most cases. The diagnostic accuracy is improved by the addition of transvaginal sonography. Even with the help of transvaginal sonography, a small proportion of ectopic pregnancies will be missed.