Catherine S. K. Cheung

Development of a quality assessment tool for systematic reviews of observational studies (QATSO) of HIV prevalence in men having sex with men and associated risk behaviours

BackgroundSystematic reviews based on the critical appraisal of observational and analytic studies on HIV prevalence and risk factors for HIV transmission among men having sex with men are very useful for health care decisions and planning. Such appraisal is particularly difficult, however, as the quality assessment tools available for use with observational and analytic studies are poorly established.MethodsWe reviewed the existing quality assessment tools for systematic reviews of observational studies and developed a concise quality assessment checklist to help standardise decisions regarding the quality of studies, with careful consideration of issues such as external and internal validity.ResultsA pilot version of the checklist was developed based on epidemiological principles, reviews of study designs, and existing checklists for the assessment of observational studies. The Quality Assessment Tool for Systematic Reviews of Observational Studies (QATSO) Score consists of five items: External validity (1 item), reporting (2 items), bias (1 item) and confounding factors (1 item). Expert opinions were sought and it was tested on manuscripts that fulfil the inclusion criteria of a systematic review. Like all assessment scales, QATSO may oversimplify and generalise information yet it is inclusive, simple and practical to use, and allows comparability between papers.ConclusionA specific tool that allows researchers to appraise and guide study quality of observational studies is developed and can be modified for similar studies in the future.

Generalized low areal and volumetric bone mineral density in adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) may be associated with generalized low bone mineral status. The bone mineral density (BMD) of 75 girls of 12–14 years of age and diagnosed as having AIS were compared with 94 age‐matched female control subjects. Areal BMD (aBMD) of the lumbar spine (L2‐L4) and the bilateral proximal femur were measured using ‐energy X‐ray absorptiometry (DEXA), and volumetric BMD (vBMD) of the nondominant distal radius and bilateral distal tibias was measured with peripheral quantitative computer tomography (pQCT). Relevant anthropometric parameters and the severity of the spinal deformity (Cobbs angle) also were evaluated and correlated with the BMD measurements. Results revealed the presence of a generalized lower bone mineral status in AIS patients. Detailed analysis showed that the aBMD and vBMD measured at the bilateral lower extremities were significantly lower in AIS patients when compared with the same in the normal controls. The most significant effect was seen in the trabecular BMD (tBMD) of the distal tibias. Of all the AIS girls, 38% of the aBMD and 36% of the vBMD were below −1 SD of the normal. BMD was found to correlate better with “years since menarche” (YSM) than with chronological age. When the BMD was evaluated for the 3 YSM groups, aBMD of the proximal femur and tBMD of distal tibias were found to be significantly lower in the AIS patients. Neither the aBMD nor the vBMD of AIS patients was found to be associated with the severity of spinal deformity. In addition, anthropometric measurements showed significantly longer arm span and lower extremities in the AIS girls. We concluded that the AIS girls had generalized lower aBMDs and vBMDs.

Balance control in adolescents with idiopathic scoliosis and disturbed somatosensory function.

Study Design. A cross-sectional study of the balance control in adolescents with idiopathic scoliosis. Objective. To investigate the relationship among somatosensory function, balance control, and adolescent idiopathic scoliosis (AIS). Summary of Background Data. Balance control requires the contribution of somatosensory, visual, and vestibular inputs. Previous studies have shown that abnormal somatosensory evoked potentials (SSEPs) were associated with AIS. Methods. A total of 105 girls with AIS and 57 normal girls aged 11–14 years entered the study, and were evaluated with bilateral tibial nerve evoked cerebral SSEPs and standing balance control under reduced or conflicting sensory conditions (i.e., the sensory organization test). One-way analysis of variance was conducted to evaluate the effects of scoliosis and somatosensory function tested by SSEPs on the performance of sensory organization test. Results. There were 15 patients with AIS who had abnormal SSEPs. Postural sway was measured on all subjects under normal, reduced, or conflicting somatosensory, visual, and vestibular conditions. One-way analysis of variance indicated no significant effect of spinal deformity or SSEPs on the balance control when there was an increased reliance on the somatosensory, visual, and vestibular systems during stance (P > 0.05). However, in the patients with abnormal SSEPs, a significant effect was found when subjects had to rely on somatosensory input for their balance control (P = 0.023). The effect of scoliosis by itself was not found to be significant (P = 1.0). Conclusions. The finding of significantly larger difference in bilateral SSEP latencies in patients with AIS indicated the association of abnormal SSEPs with AIS. The finding of a significant effect of SSEPs on the balance control further indicated the presence of abnormal somatosensory function in a subgroup of patients with AIS.

Osteopenia: A New Prognostic Factor of Curve Progression in Adolescent Idiopathic Scoliosis

BACKGROUND Studies have shown that 27% to 38% of girls with adolescent idiopathic scoliosis have systemic osteopenia. The aim of this study was to investigate whether osteopenia could serve as one of the important prognostic factors in predicting curve progression. METHODS A prospective study was performed in 324 adolescent girls with adolescent idiopathic scoliosis who had a mean age of thirteen and a half years. Bone mineral density of the spine and both hips was measured at the time of the clinical diagnosis of scoliosis. All patients were followed longitudinally until skeletal maturity or until the curve had progressed > or =6 degrees . The univariate chi-square test and stepwise logistic regression were used to predict the prevalence of curve progression, and a receiver operating characteristic curve was plotted. RESULTS The overall prevalence of curve progression was 50%. The prevalence of osteopenia at the spine and hips was 27.5% and 23.1%, respectively. A larger initial Cobb angle (odds ratio = 4.6), a lower Risser grade (odds ratio = 4.7), premenarchal status (odds ratio = 2.5), osteopenia in the femoral neck of the hip on the side of the concavity (odds ratio = 2.3), and a younger age at the time of diagnosis (odds ratio = 2.1) were identified as risk factors in predicting curve progression. A predictive model was established, and the area under the receiver operating characteristic curve of the model was 0.80 (p < 0.01). CONCLUSION Osteopenia may be an important risk factor in curve progression. The measurement of bone mineral density at the time of diagnosis may serve as an additional objective measurement in predicting curve progression in adolescent idiopathic scoliosis. The bone mineral density-inclusive predictive model may be used in treatment planning for patients with adolescent idiopathic scoliosis who are at high risk of curve progression.

Predictors of important neurological causes of dizziness among patients presenting to the emergency department.

Objectives Dizziness is a common presenting complaint in the emergency department (ED). This prospective study describes the incidence, causes and outcome of ED patients presenting with dizziness and tries to identify predictors of central neurological causes of dizziness. Methods Single-centre prospective observational study in a university teaching hospital ED in Hong Kong. All ED patients (≥18 years old) presenting with dizziness were recruited for 1 month. Symptoms, previous health, physical findings, diagnosis and disposition were recorded. The outcome at 3 months was evaluated using hospital records and telephone interviews. Follow-up was also performed at 55 months using computerised hospital records to identify patients with subsequent stroke and those who had died. Results 413 adults (65% female, mean 57 years) were recruited. The incidence of dizziness was 3.6% (413/11 319). Nausea and/or vomiting (46%) and headache (20%) were the commonest associated findings. Hypertension (33%) was the commonest previous illness. Central neurological causes of dizziness were found in 6% (23/413) of patients. Age ≥65 years (OR=6.13, 95% CI 1.97 to 19.09), ataxia symptoms (OR=11.39, 95% CI 2.404 to 53.95), focal neurological symptoms (OR=11.78, 95% CI 1.61 to 86.29), and history of previous stroke (OR=3.89, 95% CI 1.12 to 13.46) and diabetes mellitus (OR=3.57, 95% CI 1.04 to 12.28) predicted central causes of dizziness. Conclusions Most dizzy patients had benign causes. Several clinical factors favoured a diagnosis of central neurological causes of dizziness.

Neuraminidase inhibitors, superinfection and corticosteroids affect survival of influenza patients

We aimed to study factors influencing outcomes of adults hospitalised for seasonal and pandemic influenza. Individual-patient data from three Asian cohorts (Hong Kong, Singapore and Beijing; N=2649) were analysed. Adults hospitalised for laboratory-confirmed influenza (prospectively diagnosed) during 2008–2011 were studied. The primary outcome measure was 30-day survival. Multivariate Cox regression models (time-fixed and time-dependent) were used. Patients had high morbidity (respiratory/nonrespiratory complications in 68.4%, respiratory failure in 48.6%, pneumonia in 40.8% and bacterial superinfections in 10.8%) and mortality (5.9% at 30 days and 6.9% at 60 days). 75.2% received neuraminidase inhibitors (NAI) (73.8% received oseltamivir and 1.4% received peramivir/zanamivir; 44.5% of patients received NAI ≤2 days and 65.5% ≤5 days after onset of illness); 23.1% received systemic corticosteroids. There were fewer deaths among NAI-treated patients (5.3% versus 7.6%; p=0.032). NAI treatment was independently associated with survival (adjusted hazard ratio (HR) 0.28, 95% CI 0.19–0.43), adjusted for treatment-propensity score and patient characteristics. Superinfections increased (adjusted HR 2.18, 95% CI 1.52–3.11) and chronic statin use decreased (adjusted HR 0.44, 95% CI 0.23–0.84) death risks. Best survival was shown when treatment started within ≤2 days (adjusted HR 0.20, 95% CI 0.12–0.32), but there was benefit with treatment within 3–5 days (adjusted HR 0.35, 95% CI 0.21–0.58). Time-dependent analysis showed consistent results of NAI treatment (adjusted HR 0.39, 95% CI 0.27–0.57). Corticosteroids increased superinfection (9.7% versus 2.7%) and deaths when controlled for indications (adjusted HR 1.73, 95% CI 1.14–2.62). Early NAI treatment was associated with shorter length of stay in a subanalysis. NAI treatment may improve survival of hospitalised influenza patients; benefit is greatest from, but not limited to, treatment started within 2 days of illness. Superinfections and corticosteroids increase mortality. Antiviral and non-antiviral management strategies should be considered. NAI treatment, secondary infections and corticosteroids may impact on survival of hospitalised influenza patients http://ow.ly/ErOsT

High Viral Load and Respiratory Failure in Adults Hospitalized for Respiratory Syncytial Virus Infections

Abstract A prospective study among adults hospitalized for polymerase chain reaction–confirmed respiratory syncytial virus infections (n = 123) showed frequent occurrence of lower respiratory-tract complications causing respiratory insufficiency (52.8%), requirement for assisted ventilation (16.3%), and intensive care unit admission/death (12.2%). High viral RNA concentration was detected at time of hospitalization, including in patients who presented later than 2 days of illness (day 1–2, 7.29 ± 1.47; day 3–4, 7.28 ± 1.41; day 5–8, 6.66 ± 1.87 log10 copies/mL). RNA concentration was independently associated with risk of complications and respiratory insufficiency (adjusted odds ratio 1.40 per log10 copies/mL increase, 95% confidence interval, 1.03–1.90; P = .034). Our data indicate the need and provide a basis for clinical research on antiviral therapy in this population.

EMS systems in China.

The prehospital emergency service is the initial part of the Emergency Medical Service System (EMSS) in China, and is the de facto overall emergency medical service for China. As the EMSS in China continues to undergo rapid development, it faces the challenge of providing rapid response times with adequate coverage for this highly populated country. The recent Sichuan earthquake on 12 May 2008 tested the ability of the EMSS response. This article focuses on the prehospital emergency service of the EMSS and discusses the strengths and weaknesses of the current system.

Disease severity prediction for nursing home-acquired pneumonia in the emergency department

Background Prediction rules exist for the assessment of community-acquired pneumonia but their use in nursing home-acquired pneumonia (NHAP) remains undefined. The objectives of this study were to compare the prognostic ability for severe NHAP of five prediction rules (PSI, CURB-65, M-ATS, R-ATS, España rule), and to evaluate their usefulness to identify patients with less severe disease in the emergency department for outpatient care. Methods A prospective observational study of consecutive NHAP patients was conducted at a university teaching hospital emergency department in Hong Kong between January 2004 and June 2005. The primary outcome was severe pneumonia (defined as combined 30-day mortality and/or intensive care unit (ICU) admission). Results 767 consecutive NHAP patients were included. Mean (SD) age was 83.4 (9.0) years; 350 (45.6%) were male and 644 (84.0%) had coexisting illness. 95 patients died within 30 days (12.4%), five patients were admitted to the ICU (0.7%) and 98 patients had severe pneumonia (12.8%). Sensitivity and specificity of each decision rule ranged from 37.8% to 95.9% and 15.1% to 87.6% respectively. The overall predictive performance of each rule was between 0.627 and 0.712. The negative likelihood ratios of PSI (0.27) and CURB-65 (0.23) were lower than M-ATS (0.71), R-ATS (0.45) and España (0.39). After excluding 204 patients with either poor functional status or those >90 years of age, sensitivities of M-ATS (96.0%) and R-ATS (100%) improved greatly with negative likelihood ratios of <0.1. Conclusion PSI and CURB-65 are useful for identification of patients with less severe NHAP.

EMS systems in Hong Kong.

Emergency medical services (EMS) in Hong Kong, now a Special Administrative Region of the Peoples Republic of China, have a distinguished history spanning more than 50 years. This paper outlines the history and the development of the Hong Kong EMS, with a particular focus on the ambulance service, the design of the system and the training of its staff.