Interdisciplinary pharmacometrics linking oseltamivir pharmacology, influenza epidemiology and health economics to inform antiviral use in pandemics.

AIMS: A modular interdisciplinary platform was developed to investigate the economic impact of oseltamivir treatment by dosage regimen under simulated influenza pandemic scenarios. METHODS: The pharmacology module consisted of a pharmacokinetic distribution of oseltamivir carboxylate daily area under the concentration-time curve at steady state (simulated for 75 mg and 150 mg twice daily regimens for 5 days) and a pharmacodynamic distribution of viral shedding duration obtained from phase II influenza inoculation data. The epidemiological module comprised a susceptible, exposed, infected, recovered (SEIR) model to which drug effect on the basic reproductive number (R0 ), a measure of transmissibility, was linked by reduction of viral shedding duration. The number of infected patients per population of 100 000 susceptible individuals was simulated for a series of pandemic scenarios, varying oseltamivir dose, R0 (1.9 vs. 2.7), and drug uptake (25%, 50%, and 80%). The number of infected patients for each scenario was entered into the health economics module, a decision analytic model populated with branch probabilities, disease utility, costs of hospitalized patients developing complications, and case-fatality rates. Change in quality-adjusted life years was determined relative to base case. RESULTS: Oseltamivir 75 mg relative to no treatment reduced the median number of infected patients, increased change in quality-adjusted life years by deaths averted, and was cost-saving under all scenarios; 150 mg relative to 75 mg was not cost effective in low transmissibility scenarios but was cost saving in high transmissibility scenarios. CONCLUSION: This methodological study demonstrates proof of concept that the disciplines of pharmacology, disease epidemiology and health economics can be linked in a single quantitative framework.

Temperature-compensated fiber-optic 3D shape sensor based on femtosecond laser direct-written Bragg grating waveguides.

Temperature-compensated 3D fiber shape sensing is demonstrated with femtosecond laser direct-written optical and Bragg grating waveguides that were distributed axially and radially inside a single coreless optical fiber. Efficient light coupling between the laser-written optical circuit elements and a standard single-mode fiber (SMF) was obtained for the first time by 3D laser writing of a 1 × 3 directional coupler to meet with the core waveguide in the fusion-spliced SMF. Simultaneous interrogation of nine Bragg gratings, distributed along three laterally offset waveguides, is presented through a single waveguide port at 1 kHz sampling rate to follow the Bragg wavelength shifts in real-time and thereby infer shape and temperature profile unambiguously along the fiber length. This distributed 3D strain and thermal sensor is freestanding, flexible, compact, lightweight and opens new directions for creating fiber cladding photonic devices for a wide range of applications from shape and thermal sensing to guidance of biomedical catheters and tools in minimally invasive surgery.

Study of potential cardioprotective effects of Ganoderma lucidum (Lingzhi): results of a controlled human intervention trial.

Previous studies have suggested that Lingzhi (Ganoderma lucidum) has antioxidant effects and possibly beneficial effects on blood pressure, plasma lipids and glucose, but these have not been confirmed in subjects with mild hypertension or hyperlipidaemia. The objective of the present study was to assess the cardiovascular, metabolic, antioxidant and immunomodulatory responses to therapy with Lingzhi in patients with borderline elevations of blood pressure and/or cholesterol in a controlled cross-over trial. A total of twenty-six patients received 1·44 g Lingzhi daily or matching placebo for 12 weeks in a randomised, double-blind, cross-over study with placebo-controlled run-in and cross-over periods. Body weight, blood pressure, metabolic parameters, urine catecholamines and cortisol, antioxidant status and lymphocyte subsets were measured after each period. Lingzhi was well tolerated and data from twenty-three evaluable subjects showed no changes in BMI or blood pressure when treated with Lingzhi or placebo. Plasma insulin and homeostasis model assessment-insulin resistance were lower after treatment with Lingzhi than after placebo. TAG decreased and HDL-cholesterol increased with Lingzhi but not with placebo in the first treatment period, but significant carry-over effects prevented complete analysis of these parameters. Urine catecholamines and cortisol, plasma antioxidant status and blood lymphocyte subsets showed no significant differences across treatments. Results indicate that Lingzhi might have mild antidiabetic effects and potentially improve the dyslipidaemia of diabetes, as shown previously in some animal studies. Further studies are desirable in patients with hyperglycaemia.

Economic analysis between entecavir and lamivudine for the treatment of chronic hepatitis B in Hong Kong.

BACKGROUND AND AIM: Tremendous healthcare resources have been spent on the management of chronic hepatitis B (CHB) and its related complications. Therefore, a proper evaluation of the cost-effectiveness of pharmacotherapy is vital in aid of decision-making. The aim of the present study was to examine the long-term economic and clinical influence if lamivudine was replaced by entecavir in a group of CHB patients. METHODS: A recently published decision analytic model was adapted to study the cost-effectiveness of 2 years of treatment of entecavir in a hypothetical cohort of 1000 hepatitis B e antigen (HBeAg)-negative CHB patients from a public hospital perspective. Compensated cirrhosis (CC) and de-compensated cirrhosis (DC) and hepatocellular carcinoma (HCC) events were projected to 10 years. Hong Kong-specific health care costs were used. Quality Adjusted Life Years (QALYs) were calculated using the utility values obtained from a local study. RESULTS: In the base case analysis, compared with lamivudine, the use of entecavir was expected to reduce the incidences of CC, DC and HCC by 41.8%, 57.1% and 49.3%, respectively, and lead to a saving of $US 1.17 million in medical cost. The overall disease management cost for entecavir, which was 67.7% higher than lamivudine for 2 years treatment was reduced to 17.2% after projecting 2-year treatment duration to 10 years. The incremental cost per QALY gained for entecavir compared with lamivudine was $US 13 759. CONCLUSIONS: Based on the recommended cost-effectiveness threshold of the World Health Organization, entecavir is considered cost-effective compared with lamivudine in treating CHB in Hong Kong when long term medical consequences were considered.

Combined antibiotic/corticosteroid cream in the empirical treatment of moderate to severe eczema: friend or foe?

BACKGROUND: Eczema is a common atopic disease associated with pruritus, sleep disturbance, and impaired quality of life. Staphylococcus aureus colonization/infection is important in its pathophysiology. AIM: To evaluate the prevalence of S aureus colonization/infection and the efficacy and acceptability of a combined antibiotic/corticosteroid cream in the empirical treatment of eczema. METHODS: Consecutive patients with moderate to severe eczema were recruited. Swab and cultures from the right antecubital fossa and the worst eczematous area, disease severity (SCORAD) and quality of life (Children's Dermatology Life Quality Index, CDLQI), skin hydration (SH), and transepidermal water loss (TEWL) were obtained prior to and following a two week twice-daily course of treatment with a fucidin/corticosteroid cream. General acceptability of treatment (GAT) was documented at completion. RESULTS: Thirty-five patients (63% males; mean age 13.5, standard deviation 3.6 years; with 21 moderate and 14 severe disease) were recruited. At start, S aureus was isolated from the right antecubital fossa and the worst affected areas in 66% and 71% of these patients, respectively. At completion, S aureus was isolated in 23% and 40% at the antecubital fossae and worst affected areas (P=0.001 and P=0.003, respectively). No methicillin-resistant S aureus was isolated in this series, but the percentage of fucidin-resistant S aureus increased from 8% to 58% (P<0.001). Disease severity and quality of life were significantly improved (pre-Objective SCORAD and post-Objective SCORAD were 38.4±13.7 and 29.7±14.2, P<0.001; pre-CDLQI and post-CDLQI were 9.4±5.2 and 7.1±4.8, P<0.001). At the right antecubital fossa, skin hydration improved from 30.8±14.2 to 36.7±15.2 (P=0.015); and TEWL from 10.7±2.3 to 9.4±2.2 (P<0.001). Eighty percent of patients found the treatment good or very good, and only one (3%) patient found it unacceptable. CONCLUSIONS: The most prevalent organism in moderate to severe eczema was S aureus. Usage of the combined fucidin/corticosteroid cream is convenient and associated with a reduction in disease severity, improvement in quality of life, SH, and TEWL, but caution has to be taken with emergence of fucidin-resistant S aureus.

Pseudoceramide for childhood eczema: does it work?

OBJECTIVES: Atopic eczema is a chronic relapsing skin disease associated with atopy, and characterised by reduced skin hydration, impaired skin integrity (transepidermal water loss), and poor quality of life. Proper emollient usage is an important facet of its management. This study aimed to establish an approach to evaluate the efficacy of using an emollient over a 4-week period. DESIGN: Prospective observational study. SETTING: A paediatric dermatology out-patient clinic of a university teaching hospital in Hong Kong. PATIENTS: Consecutive new patients aged 5 to 18 years with atopic eczema diagnosed according to Hanifin and Rajka's criteria were recruited from March to August 2009. They or their parents were instructed to liberally apply the test emollient to the flexures and areas affected with eczema, twice daily. Outcome assessments were repeated 2 and 4 weeks later. MAIN OUTCOME MEASURES: Skin hydration and transepidermal water loss in the right forearm (2 cm below antecubital flexure), and disease severity (SCORing Atopic Dermatitis index) and Children's Dermatology Life Quality Index. At the end of the study period, a global assessment of treatment was recorded. RESULTS: Thirty-three patients with atopic eczema were recruited and treated with applications of a pseudoceramide-containing cream (Curel, Kao, Japan). The mean age of the patients (16 males and 17 females) was 12 (standard deviation, 4) years. Four weeks following the use of the cream, skin hydration improved significantly and fewer patients were using topical corticosteroids. In these patients, there was no deterioration in transepidermal water loss, eczema severity, or quality of life. CONCLUSION: The pseudoceramide cream improved skin hydration but not severity or quality of life over a 4-week usage.

Omeprazole before endoscopy in patients with gastrointestinal bleeding.

BACKGROUND: A neutral gastric pH is critical for the stability of clots over bleeding arteries. We investigated the effect of preemptive infusion of omeprazole before endoscopy on the need for endoscopic therapy. METHODS: Consecutive patients admitted with upper gastrointestinal bleeding underwent stabilization and were then randomly assigned to receive either omeprazole or placebo (each as an 80-mg intravenous bolus followed by an 8-mg infusion per hour) before endoscopy the next morning. RESULTS: Over a 17-month period, 638 patients were enrolled and randomly assigned to omeprazole or placebo (319 in each group). The need for endoscopic treatment was lower in the omeprazole group than in the placebo group (60 of the 314 patients included in the analysis [19.1%] vs. 90 of 317 patients [28.4%], P=0.007). There were no significant differences between the omeprazole group and the placebo group in the mean amount of blood transfused (1.54 and 1.88 units, respectively; P=0.12) or the number of patients who had recurrent bleeding (11 and 8, P=0.49), who underwent emergency surgery (3 and 4, P=1.00), or who died within 30 days (8 and 7, P=0.78). The hospital stay was less than 3 days in 60.5% of patients in the omeprazole group, as compared with 49.2% in the placebo group (P=0.005). On endoscopy, fewer patients in the omeprazole group had actively bleeding ulcers (12 of 187, vs. 28 of 190 in the placebo group; P=0.01) and more omeprazole-treated patients had ulcers with clean bases (120 vs. 90, P=0.001). CONCLUSIONS: Infusion of high-dose omeprazole before endoscopy accelerated the resolution of signs of bleeding in ulcers and reduced the need for endoscopic therapy. (ClinicalTrials.gov number, NCT00164866 [ClinicalTrials.gov] .).

High-power wavelength-swept laser in Littman telescope-less polygon filter and dual-amplifier configuration for multichannel optical coherence tomography.

We report a high-power wavelength-swept laser source for multichannel optical coherence tomography (OCT) imaging. Wavelength tuning is performed by a compact telescope-less polygon-based filter in Littman arrangement. High output power is achieved by incorporating two serial semiconductor optical amplifiers in the laser cavity in Fourier domain mode-locked configuration. The measured wavelength tuning range of the laser is 111 nm centered at 1329 nm, coherence length of 5.5 mm, and total average output power of 131 mW at 43 kHz sweeping rate. Multichannel simultaneous OCT imaging at an equivalent A-scan rate of 258 kHz is demonstrated.

Economic evaluation of universal infant vaccination with 7vPCV in Hong Kong.

OBJECTIVES: The purpose of this study was to evaluate the clinical and economic benefits of routine infant vaccination with seven-valent pneumococcal conjugate vaccine (7vPCV) in Hong Kong. METHODS: A decision-analytic model was populated with local age-specific incidence data to simulate the expected health outcomes resulting from 7vPCV vaccination of a birth cohort of 57,100 children compared with an unvaccinated cohort over a 10-year horizon. Primary analyses were conducted from a payer perspective, using local inpatient and outpatient costs associated with the treatment of pneumococcal disease. Vaccine efficacy rates were consistent with results from pivotal clinical trials. The reduction in adult invasive pneumococcal disease (IPD) and associated cost avoidance due to the indirect effect of vaccination were estimated in line with published overseas rates. RESULTS: Universal 7vPCV vaccination was estimated to prevent 524 cases of IPD and more than 2580 cases of otitis media in the birth cohort over a 10-year period, leading to a reduction of HK$28.7 million (US$3.7 million) in direct medical costs. Additional cost savings from the indirect prevention of 919 adult cases of IPD during this time period also resulted. Overall, 7vPCV vaccination was estimated to have an incremental cost per life-year gained of HK$50,456 (US$6460) from a payer perspective or HK$46,308 (US$5929) when both direct and indirect costs were included. CONCLUSION: With reference to the World Health Organization's threshold for cost-effectiveness, results from this study indicate that routine infant vaccination with 7vPCV is a cost-effective intervention because of the added cost savings resulting from the indirect effect of vaccination on adult disease.

A cost-minimisation analysis comparing different antibiotic regimens used in treating all-cause bacterial pneumonia in Hong Kong.

BACKGROUND: To find out the antibiotic treatment regimens with the lowest cost for all-cause bacterial pneumonia, a study to compare the costs of different antibiotic regimens in the treatment of patients diagnosed with all-cause bacterial pneumonia who required hospitalisation was carried out. METHODOLOGY: This was a multicentre, retrospective study of patient medical records. The primary aim was to examine whether the initial choice of antibiotic had affected the total cost of treatment, while the secondary aim was to find out whether the initial choice of antibiotic had affected the initial treatment failure rates and death rates. A cost-minimisation analysis (CMA) from a public hospital perspective was employed. RESULTS: A total of 333 patient medical case notes were reviewed. The most commonly prescribed antibiotic regimen was amoxycillin-clavulanate (AC) followed by amoxycillin-clavulanate plus macrolide (ACM) and quinolone (Q). In the study population, no statistical significance could be detected between the mean cost of the three regimens. In the subgroup analysis of patients with a history of chronic obstructive pulmonary disease (COPD) and patients with a history of smoking, the Q regimen appeared to be the least expensive. CONCLUSION: In the study population, no significant difference could be identified between the mean cost of the three antibiotic regimens. In a special populations such as patients with a history of COPD and patients with a history of smoking, the Q regimen appeared to be superior. Further studies in these areas are needed.

Real-world evidence of improved healthcare utilization in patients with schizophrenia or schizoaffective disorder after early treatment of paliperidone palmitate once-monthly treatment in Hong Kong.

BACKGROUND: Very few data are available to demonstrate the economic benefit of early paliperidone palmitate once-monthly long-acting injectable (PP1M) treatment in patients with schizophrenia or schizoaffective disorder. METHODS AND MATERIALS: This study has retrospectively compared the healthcare utilization and associated costs of pre- and post-PPIM treatment in 413 patients with schizophrenia or schizoaffective disorder recruited from three major public hospitals providing psychiatric services in Hong Kong. Patients were categorized into early treatment (≤3 years since diagnosis) and chronic (>3 years) groups, and also whether they were receiving polypharmacy (POP). RESULTS: It was found that patients who were started on early therapy with no POP had the most favourable outcomes. Overall results of the entire cohort, including both early and late treatments, indicate that there was a slight increase in annual in-patient days (IP) per patient and outpatient visit (OP) by 3.18 and 1.87, respectively, and a decrease in emergency room visit (ER) of 0.9 (p < 0.05). For non-polypharmacy (NP) patients receiving early PP1M therapy, there was a significant decrease in IP and ER of 21.56 (p < 0.05) and 1.15 (p < 0.05), respectively, but an increase in OP of 1.88 (p < 0.05). For patients with POP, there was an all-across increase in IP and all-across decrease in OP and ER. In monetary terms, a NP patient receiving early therapy may have an overall saving of HKD40,878 (USD5,241, 1USD = 7.8HKD) per year compared to HKD6,224 (USD798) in patients where therapy was given after 3 years. For patients with POP, there was an all-across increase in overall spending despite reductions in OP and ER. CONCLUSIONS: From the 413 patients studied, potential annual savings is higher by early administration of PPIM in patients with NP. Analysis using multivariate linear regression based on generalized estimating equations and sensitivity analysis using a linear mixed model supported the findings.

Clopidogrel versus aspirin and esomeprazole to prevent recurrent ulcer bleeding.

BACKGROUND: Concurrent therapy with a proton-pump inhibitor is a standard treatment for patients receiving aspirin who are at risk for ulcer. Current U.S. guidelines also recommend clopidrogel for patients who have major gastrointestinal intolerance of aspirin. We compared clopidogrel with aspirin plus esomeprazole for the prevention of recurrent bleeding from ulcers in high-risk patients. METHODS: We studied patients who took aspirin to prevent vascular diseases and who presented with ulcer bleeding. After the ulcers had healed, we randomly assigned patients who were negative for Helicobacter pylori to receive either 75 mg of clopidogrel daily plus esomeprazole placebo twice daily or 80 mg of aspirin daily plus 20 mg of esomeprazole twice daily for 12 months. The end point was recurrent ulcer bleeding. RESULTS: We enrolled 320 patients (161 patients assigned to receive clopidogrel and 159 to receive aspirin plus esomeprazole). Recurrent ulcer bleeding occurred in 13 patients receiving clopidogrel and 1 receiving aspirin plus esomeprazole. The cumulative incidence of recurrent bleeding during the 12-month period was 8.6 percent (95 percent confidence interval, 4.1 to 13.1 percent) among patients who received clopidogrel and 0.7 percent (95 percent confidence interval, 0 to 2.0 percent) among those who received aspirin plus esomeprazole (difference, 7.9 percentage points; 95 percent confidence interval for the difference, 3.4 to 12.4; P=0.001). CONCLUSIONS: Among patients with a history of aspirin-induced ulcer bleeding whose ulcers had healed before they received the study treatment, aspirin plus esomeprazole was superior to clopidogrel in the prevention of recurrent ulcer bleeding. Our finding does not support the current recommendation that patients with major gastrointestinal intolerance of aspirin be given clopidogrel.

Cholesterol goal attainment in patients with coronary heart disease and elevated coronary risk: results of the Hong Kong hospital audit study.

OBJECTIVE: We sought to determine 1) long-term lipid-lowering treatment patterns; 2) cholesterol goal attainment rates and possible determinants of goal achievement; and 3) effects of cholesterol goal attainment on coronary events in hospitalized Hong Kong patients. METHODS: In this retrospective cohort analysis, records of two public Hong Kong hospitals were reviewed for 196 adults (69% with coronary heart disease (CHD) or CHD-risk equivalent) who received at least one lipid-lowering therapy during hospitalization. Low-density lipoprotein cholesterol (LDL-C) targets were <2.6 mmol/l (<100 mg/dL) for patients with CHD or CHD risk equivalents and <3.37 mmol/l (<130 mg/dL) for those without. RESULTS: Most participants were initiated on regimens of low to midequipotency doses and never had their regimens adjusted to higher potency. Approximately 44% of patients not at LDL-C at baseline failed to achieve goal during a median follow-up of 1.9 years. Patients with higher coronary risk and/or LDL-C levels at baseline were less likely than their lower-risk counterparts to achieve goal; for each 1-mmol/l (38.7-mg/dL) increase in LDL-C at baseline, the likelihood of attaining goal declined by 64%. Patients achieving cholesterol goal had significantly longer cardiovascular event-free times. CONCLUSIONS: A total of 44% of Hong Kong patients not at LDL-C goals at baseline did not achieve them over 1.9 years. More effective and well-tolerated therapies, including adjunctive regimens (e.g., ezetimibe-statin, niacin-statin), may be necessary to enhance LDL-C goal achievement and increase event-free time.

Statin utilization patterns for the primary prevention of cardiovascular events: a retrospective study in patients with diabetes mellitus in Hong Kong.

BACKGROUND AND OBJECTIVE: In Hong Kong, about 10% of adults 25-74 years of age have diabetes mellitus. The management of dyslipidemia with lipid-lowering agents (LLAs), including HMG-CoA reductase inhibitors (statins) for the primary prevention of cardiovascular complications, has been found to be beneficial. This study examined statin utilization patterns for the primary prevention of cardiovascular events in patients with diabetes mellitus in two public hospitals in Kong Kong; clinical outcomes in patients who received statins for primary prevention were compared with those in patients not treated with any LLAs. METHODS: This was a retrospective study in patients who were diagnosed with diabetes mellitus. Only patients with no prior history of coronary artery disease were included in the study. Utilization patterns of LLAs and the incidences of cardiovascular complications were recorded from 1 January 2002 to 31 December 2003. RESULTS: A total of 222 patient records were reviewed. Only 75/222 (33.8%) of patients with diabetes mellitus received one or more LLAs for the primary prevention of cardiovascular events. Among these patients, only 21% of patients attained target lipid goals. Nearly half of the patients who were not treated with LLAs (n=147) had dyslipidemia problems. The overall incidence of cardiovascular complications in patients treated and not treated with LLAs was 12.2%. Absence of routine screening for cardiovascular risk and sub-optimal utilization and inadequate dosage titration of LLAs were identified as contributory factors towards cardiovascular events in this patient group. CONCLUSION: The current study failed to prove the benefits of LLAs in reducing the risk of first cardiovascular events in diabetic patients. This may have been due to the use of low doses of LLAs and a lack of laboratory monitoring of cholesterol levels. Development and implementation of guidelines may help promote the use of LLAs in primary prevention of cardiovascular complications.

A study of the health and economic effects of influenza-like illness on the working population under different working environments of a large corporation in Hong Kong.

OBJECTIVE: The incidence, health and economic impacts of influenza-like illness (ILI) among the working population in Hong Kong had never been studied. Due to the nature of the disease, ILIs can have a significant impact on the operation of a corporation in terms of loss of productivity and reduced work performance. The present study was undertaken to determine the health and economic impacts of ILIs under different environmental conditions on the working population of a large corporation. METHOD: Over 2,000 employees of a large corporation in the travelling and tourism industry were studied with three different types of working environment (confined, typical office and well ventilated) by two structured questionnaires. RESULTS: The most affected group in terms of productivity and health was the group working in a confined area, whilst those working in a well-ventilated area were least affected. However, symptoms of the confined area group seemed to disappear faster. The infection rate appeared to vary according to work environment for the studied population. CONCLUSION: Policies on preventive measures and early treatment are important for a corporation to reduce loss in productivity due to ILIs.