SABINA + Hong Kong: a territory wide study of prescribing trends and outcomes associated with the use of short-acting β2 agonists in the Chinese population

BACKGROUND

Excessive use of short-acting β2 agonists (SABA) in patients with asthma continues to be a notable concern due to its link to higher mortality rates. Global relevance of SABA overuse in asthma management cannot be understated, it poses significant health risk to patients with asthma and imposes burden on healthcare systems. This study, as part of global SABINA progamme, aimed to describe the prescribing patterns and clinical outcomes associated with SABA use in the Chinese population.

METHODS

Retrospective cohort study was conducted using anonymized electronic healthcare records of Clinical Data Analysis and Reporting System (CDARS) from Hong Kong Hospital Authority (HA). Patients newly diagnosed with asthma between 2011 and 2018 and aged ≥12 years were included, stratified by SABA use (≤2, 3-6, 7-10, or ≥11 canisters/year) during one-year baseline period since asthma diagnosis date. Patients were followed up from one-year post-index until earliest censoring of events: outcome occurrence and end of study period (31 December 2020). Cox proportional regression and negative binomial regression were used to estimate the mortality risk and frequency of hospital admissions associated with SABA use respectively, after adjusting for age, sex, Charlson Comorbidity Index (CCI), and inhaled corticosteroid (ICS) dose. Outcomes include all-cause, asthma-related, and respiratory-related mortality, frequency of hospital admissions for any cause, and frequency of hospital admissions due to asthma.

RESULTS

17,782 patients with asthma (mean age 46.7 years, 40.8% male) were included and 59.1% of patients were overusing SABA (≥ 3 canisters per year). Each patient was prescribed a median of 5.61 SABA canisters/year. SABA overuse during baseline period was associated with higher all-cause mortality risk compared to patients with ≤2 canisters/year. Association was dose-dependent, highest risk in those used ≥11 canisters/year (adjusted hazard ratio: 1.42, 95% CI: 1.13, 1.79) and 3-6 canisters/year (adjusted hazard ratio: 1.22, 95% CI: 1.00, 1.50). Higher SABA prescription volume associated with increased frequency of hospital admissions with greatest risk observed in 7-10 canisters/year subgroup (adjusted rate ratio: 4.81, 95% CI: 3.66, 6.37).

CONCLUSIONS

SABA overuse is prevalent and is associated with increased all-cause mortality risk and frequency of hospital admissions among the patients with asthma in Hong Kong.

Association between prenatal antipsychotic exposure and the risk of attention-deficit/hyperactivity disorder and autism spectrum disorder: a systematic review and meta-analysis

The paucity of evidence regarding the safety of gestational antipsychotic exposure has led to treatment discontinuation in pregnant women with severe mental health conditions. This systematic review and meta-analysis aimed to summarise the current evidence on the association between gestational antipsychotic exposure and attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in children (Study protocol registered in PROSPERO:CRD42022311354). Five studies included in our meta-analysis with around 8.6 million pregnancy episodes in nine different countries/regions. Results from our meta-analysis indicate that the heightened risks of ASD and ADHD in children gestationally exposed to antipsychotics appear to be attributable to maternal characteristics, rather than having a causal relationship with the antipsychotic exposure during pregnancy. The results underscore the importance of meticulously monitoring the neurodevelopment of children born to mothers with mental illnesses, which can facilitate early interventions and provide requisite support.

The trends in lung cancer prevalence, incidence, and survival in Hong Kong over the past two decades (2002-2021): a population-based study

Background

Over the past decades, significant progress in lung cancer management has been made. However, the trends in prevalence and survival of lung cancer in the Chinese population over the last decade remain unexplored. This study utilised a territory-wide electronic medical database in Hong Kong to provide the most up-to-date and comprehensive analysis of the trends in prevalence, incidence, and survival over the past two decades.

Methods

Descriptive epidemiology study using a retrospective cohort of lung cancer patients from the Clinical Data Analysis and Reporting System (CDARS). 10-year limited-duration prevalence, incidence, and relative period survival were calculated between 2002 and 2021. Sub-groups of age, sex, and comorbidity were examined. The annual percent change (APC) and average annual percent change (AAPC) were estimated using joinpoint regression.

Findings

This study included 87,259 incident cases between 2002 and 2021. The 10-year limited duration prevalence (per 100,000 persons) of lung cancer increased from 153.4 to 228.7 (AAPC: 3.08%). Crude incidence (per 100,000 persons) increased from 55.0 to 70.3 (APC: 1.23%), while age-standardised incidence decreased from 42.9 to 33.2 (APC: -1.32%). The 1-year and 5-year relative period survivals showed an increasing trend but remained low. Disparity in trends was observed among different sex and age groups.

Interpretation

Lung cancer burden has been increasing partly due to population ageing. Although survival showed improvement over the years, it remained low, highlighting the potential need for interventions. Further study exploring the disparity in sex-specific trends is warranted.

Funding

The Innovation and Technology Commission, Hong Kong.

Oral morphine versus transmucosal diamorphine for breakthrough pain in children: methods and outcomes: UK (DIPPER study) consensus

OBJECTIVES

No randomised controlled trials have been conducted for breakthrough pain in paediatric palliative care and there are currently no standardised outcome measures. The DIPPER study aims to establish the feasibility of conducting a prospective randomised controlled trial comparing oral and transmucosal administration of opioids for breakthrough pain. The aim of the current study was to achieve consensus on design aspects for a small-scale prospective study to inform a future randomised controlled trial of oral morphine, the current first-line treatment, versus transmucosal diamorphine.

METHODS

The nominal group technique was used to achieve consensus on best practice for mode of administration, dose regimen and a range of suitable pain intensity outcome measures for transmucosal diamorphine in children and young people with breakthrough pain. An expert panel of ten clinicians in paediatric palliative care and three parent representatives participated. Consensus was achieved when agreement was reached and no further comments from participants were forthcoming.

RESULTS

The panel favoured the buccal route of administration, with dosing according to the recommendations in the Association for Paediatric Palliative Medicine formulary (fifth Edition, 2020). The verbal Numerical Rating Scale was selected to measure pain in children 8 years old and older, the Faces Pain Scale-Revised for children between 4 and 8 years old, and Face, Legs, Activity, Cry and Consolability (FLACC)/FLACC-Revised as the observational tools.

CONCLUSIONS

The nominal group technique allowed consensus to be reached for a small-scale, prospective, cohort study and provided information to inform the design of a randomised controlled trial.

ADHD medication discontinuation and persistence across the lifespan: a retrospective observational study using population-based databases

BACKGROUND

Although often intended for long-term treatment, discontinuation of medication for ADHD is common. However, cross-national estimates of discontinuation are missing due to the absence of standardised measures. The aim of this study was to determine the rate of ADHD treatment discontinuation across the lifespan and to describe similarities and differences across countries to guide clinical practice.

METHODS

We did a retrospective, observational study using population-based databases from eight countries and one Special Administrative Region (Australia, Denmark, Hong Kong, Iceland, the Netherlands, Norway, Sweden, the UK, and the USA). We used a common analytical protocol approach and extracted prescription data to identify new users of ADHD medication. Eligible individuals were aged 3 years or older who had initiated ADHD medication between 2010 and 2020. We estimated treatment discontinuation and persistence in the 5 years after treatment initiation, stratified by age at initiation (children [age 4-11 years], adolescents [age 12-17 years], young adults [age 18-24 years], and adults [age ≥25 years]) and sex. Ethnicity data were not available.

FINDINGS

1 229 972 individuals (735 503 [60%] males, 494 469 females [40%]; median age 8-21 years) were included in the study. Across countries, treatment discontinuation 1-5 years after initiation was lowest in children, and highest in young adults and adolescents. Within 1 year of initiation, 65% (95% CI 60-70) of children, 47% (43-51) of adolescents, 39% (36-42) of young adults, and 48% (44-52) of adults remained on treatment. The proportion of patients discontinuing was highest between age 18 and 19 years. Treatment persistence for up to 5 years was higher across countries when accounting for reinitiation of medication; at 5 years of follow-up, 50-60% of children and 30-40% of adolescents and adults were covered by treatment in most countries. Patterns were similar across sex.

INTERPRETATION

Early medication discontinuation is prevalent in ADHD treatment, particularly among young adults. Although reinitiation of medication is common, treatment persistence in adolescents and young adults is lower than expected based on previous estimates of ADHD symptom persistence in these age groups. This study highlights the scope of medication treatment discontinuation and persistence in ADHD across the lifespan and provides new knowledge about long-term ADHD medication use.

FUNDING

European Union Horizon 2020 Research and Innovation Programme.

Cardiovascular risk in rheumatoid arthritis patients treated with targeted synthetic and biological disease-modifying antirheumatic drugs: A multi-centre cohort study

BACKGROUND

This study aimed to compare the cardiovascular safety of interleukin-6 inhibitors (IL-6i) and Janus Kinase inhibitors (JAKi) to tumour necrosis factor inhibitors (TNFi).

METHODS

We conducted a retrospective cohort study using population-based electronic databases from Hong Kong, Taiwan and Korea. We identified newly diagnosed patients with rheumatoid arthritis (RA) who received b/tsDMARDs first time. We followed patients from b/tsDMARD initiation to the earliest outcome (acute coronary heart disease, stroke, heart failure, venous thromboembolism and systemic embolism) or censoring events (death, transformation of b/tsDMARDs on different targets, discontinuation and study end). Using TNFi as reference, we applied generalized linear regression for the incidence rate ratio estimation adjusted by age, sex, disease duration and comorbidities. Random effects meta-analysis was used for pooled analysis.

RESULTS

We identified 8689 participants for this study. Median (interquartile range) follow-up years were 1.45 (2.77) in Hong Kong, 1.72 (2.39) in Taiwan and 1.45 (2.46) in Korea. Compared to TNFi, the adjusted incidence rate ratios (aIRRs) (95% confidence interval [CI]) of IL-6i in Hong Kong, Taiwan and Korea are 0.99 (0.25, 3.95), 1.06 (0.57, 1.98) and 1.05 (0.59, 1.86) and corresponding aIRR of JAKi are 1.50 (0.42, 5.41), 0.60 (0.26, 1.41), and 0.81 (0.38, 1.74), respectively. Pooled aIRRs showed no significant risk of cardiovascular events (CVEs) associated with IL-6i (1.05 [0.70, 1.57]) nor JAKi (0.80 [0.48, 1.35]) compared to TNFi.

CONCLUSION

There was no difference in the risk of CVE among RA patients initiated with IL-6i, or JAKi compared to TNFi. The finding is consistent in Hong Kong, Taiwan and Korea.

Associations between usual glycated haemoglobin and cardiovascular disease in patients with type 2 diabetes mellitus: A 10-year diabetes cohort study

AIM

To investigate the assocation between glycated haemoglobin (HbA1c) level and cardiovascular disease (CVD) risk among patients with type 2 diabetes.

MATERIALS AND METHODS

This retrospective cohort study conducted in Hong Kong selected patients aged 45 to 84 years with type 2 diabetes mellitus and without CVD from primary care clinics during the period 2008 to 2010. Usual HbA1c measurement was calculated using a mixed-effects model to minimize regression dilution bias. The association between usual HbA1c and CVD risk was assessed by Cox regression, with adjustment for baseline covariates. Subgroup analyses by patient characteristics were also conducted.

RESULTS

After a median follow-up period of 8.4 years (1.4 million person-years), 174 028 patients with 34 074 CVD events were observed. A curvilinear association was found between usual HbA1c and total CVD, stroke, heart failure and CVD mortality risk. No significant difference was found among patients with usual HbA1c <53 mmol/mol (7%). A positive linear association was found between usual HbA1c and the risks of outcomes when the usual HbA1c was 53 mmol/mol (7%) or above. The adjusted hazard ratios (HRs) for CVD risk per 1% increment in usual HbA1c >7% was 21% (HR 1.21, 95% confidence interval [CI] 1.18-1.23) (HR for CVD per 1mmol/mol increment in usual HbA1c > 53 mmol/mol was 1.7% (HR 1.017, CI 1.015-1.019)). A similar pattern was identified in a patient subgroup analysis, but the effects of usual HbA1c in younger patients were more prominent than in older patients.

CONCLUSIONS

Usual HbA1c increments for levels >53 mmol/mol (7.0%) were associated with elevated CVD risk, but no difference was found in the population with usual HbA1c <53 mmol/mol (7.0%), irrespective of patient characteristics. For CVD prevention, strict adherence to an HbA1c target of <53 mmol/mol (7%) should apply to younger patients.

False-positive SARS-CoV-2 serology in 3 children with Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is an acute febrile and eruptive disease with systemic vasculitis predominantly affecting young East Asian children. Recent reports showed that children with KD-like disease from KD low prevalence regions had positive SARS-CoV-2 serology despite a negative SARS-CoV-2 polymerase chain reaction (PCR) in respiratory samples.

OBJECTIVES

To describe 3 pediatric Kawasaki Disease patients with false positive SARS-CoV-2 serology.

STUDY DESIGN

We retrospectively recruited children with KD diagnosed during the COVID-19 outbreak in Hong Kong. Clinical characteristics and laboratory test results including SARS-CoV-2 PCR results were retrieved. We performed a microparticle-based immunoassay for the detection of IgG against nucleoprotein (NP) and spike protein receptor binding domain (RBD), and a microneutralization assay for the detection of neutralizing antibodies.

RESULTS

Three Chinese children with typical KD were identified. They had no epidemiological links with COVID-19 patients and tested negative for SARS-CoV-2 NPA PCR. They were treated with IVIG and aspirin, and were discharged without complications. Subsequently 2 of them were tested positive against anti-RBD and anti-NP antibodies and 1 was tested positive against anti- RBD antibodies. However, microneutralization assay showed that neutralizing antibodies were absent, suggesting a false-positive IgG result.

CONCLUSION

Detection of neutralizing antibodies is recommended to confirm previous SARS-CoV-2 infection in IgG-positive but PCR-negative patients.

Nitrogen-Containing Bisphosphonates Are Associated With Reduced Risk of Pneumonia in Patients With Hip Fracture

The objective of this work was to study the risk of pneumonia and pneumonia mortality among patients receiving nitrogen-containing bisphosphonates (N-BPs), non-N-BP anti-osteoporosis medications, and no anti-osteoporosis medications after hip fracture. We studied a historical cohort using a population-wide database. Patients with first hip fracture during 2005-2015 were identified and matched by time-dependent propensity score. The cohort was followed until December 31, 2016, to capture any pneumonia and pneumonia mortality. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox-proportional hazards regression. Absolute risk difference (ARD) and number needed to treat (NNT) were calculated. We identified 54,047 patients with hip fracture. Of these, 4041 patients who received N-BPs and 11,802 without anti-osteoporosis medication were propensity score-matched. N-BPs were associated with a significantly lower risk of pneumonia compared with no treatment (6.9 versus 9.0 per 100 person-years; HR 0.76; 95% CI, 0.70 to 0.83), resulting in an ARD of 0.02 and NNT of 46. A similar association was observed with pneumonia mortality (HR 0.65; 95% CI, 0.56 to 0.75). When N-BPs were compared with non-N-BP anti-osteoporosis medications, the association remained significant. N-BPs were associated with lower risks of pneumonia and pneumonia mortality. Randomized controlled trials are now required to determine whether N-BPs, non-vaccine-based medications, can reduce pneumonia incidence in high risk groups. © 2020 American Society for Bone and Mineral Research.

Coronavirus disease 2019 (COVID-19): latest developments in potential treatments

Many viral respiratory infections can cause severe acute respiratory symptoms leading to mortality and morbidity. In the spring of 2003, the severe acute respiratory syndrome (SARS) outbreak caused by SARS-CoV spread globally. In the summer of 2012, the Middle East respiratory syndrome (MERS) outbreak caused by MERS-CoV occurred in Saudi Arabia. In the winter of 2019, the coronavirus disease 2019 (COVID-19) outbreak caused by a novel coronavirus SARS-CoV-2 occurred in China which rapidly spread worldwide causing a global pandemic. Up until 27 May 2020, there are 5.5 million confirmed cases of COVID-19 and 347,587 COVID-19 related deaths worldwide, and there has also been an unprecedented increase in socioeconomic and psychosocial issues related to COVID-19. This overview aims to review the current developments in preventive treatments and therapies for COVID-19. The development of vaccines for SARS-CoV-2 is ongoing and various clinical trials are currently underway around the world. It is hoped that existing antivirals including remdesivir and lopinavir-ritonavir might have roles in the treatment of COVID-19, but results from trials thus far have not been promising. COVID-19 causes a mild respiratory disease in the majority of cases, but in some cases, cytokine activation causes sepsis and acute respiratory distress syndrome, leading to morbidity and mortality. Immunomodulatory treatments and biologics are also being actively explored as therapeutics for COVID-19. On the other hand, the use of steroidal and nonsteroidal anti-inflammatory drugs (NSAIDs) has been discouraged based on concerns about their adverse effects. Over the past two decades, coronaviruses have caused major epidemics and outbreaks worldwide, whilst modern medicine has been playing catch-up all along.

Incidences, temporal trends and risks of hospitalisation for gastrointestinal bleeding in new or chronic low-dose aspirin users after treatment for Helicobacter pylori: a territory-wide cohort study

OBJECTIVE

The risk of GI bleeding (GIB) in aspirin users after Helicobacter pylori (HP) eradication remains poorly defined. We characterised the incidences and temporal trends of hospitalisations for all GIB in aspirin users after HP eradication therapy.

DESIGN

Based on a territory-wide health database, we identified all patients who had received the first course of clarithromycin-based triple therapy between 2003 and 2012. Patients were divided into three cohorts according to aspirin use: new users (commenced after HP eradication), chronic users (commenced before and resumed after HP eradication) and non-users. The primary outcome was to determine the risk of hospitalisation for GIB.

RESULTS

We included 6985 new aspirin users, 5545 chronic users and 48 908 non-users. The age-adjusted and sex-adjusted incidence of hospitalisation for all GIB in new, chronic and non-users was 10.4, 7.2 and 4.6 per 1000 person-years, respectively. Upper and lower GIB accounted for 34.7% and 45.3% of all bleeding, respectively. Compared with chronic users, new users had a higher risk of GIB (HR with propensity score matching: 1.89; 95% CI 1.29 to 2.70). Landmark analysis showed that the increased risk in new aspirin users was only observed in the first 6 months for all GIB (HR 2.10, 95% CI 1.41 to 3.13) and upper GIB (HR 2.52, 95% CI 1.38 to 4.60), but not for lower GIB.

CONCLUSION

New aspirin users had a higher risk of GIB than chronic aspirin users, particularly during the initial 6 months. Lower GIB is more frequent than upper GIB in aspirin users who had HP eradicated.

Risk factors for drug allergies in Chinese children

BACKGROUND

Drug allergy, or drug hypersensitivity, is a potentially fatal disorder, and patients labeled with drug allergies have restricted access to first-line treatments. Full knowledge of the characteristics associated with drug allergies and severe reactions during allergy evaluation is beneficial for appropriate risk stratification.

OBJECTIVE

We sought to determine whether certain clinical characteristics are associated with drug allergies in Chinese children.

METHODS

Charts were reviewed for ethnic Chinese patients less than 18 years old referred to our tertiary allergy center for suspected drug allergies and completed skin and drug provocative testing between 2005 to 2017. Univariate and multivariate analyses were performed on the age of onset of drug allergies, gender, and other atopy versus drug allergies.

RESULTS

Out of 75 children, 18 (24%) had IgE-mediated drug allergies, while 8 (10.7%) had delayed drug hypersensitivities, with a cumulative 26 subjects (34.7%) with any drug hypersensitivity. There were positive independent associations between drug hypersensitivities onset age vs IgE-mediated drug allergies (odds ratio (OR) = 14.9, 95% confidence intervals (CIs) = 1.5-148.3, P = 0.017) and between male gender and IgE-mediated drug allergies (OR = 4.4, CIs = 1.2-16.4, P = 0.019). Age 13 years was the best cut-off for IgE-mediated drug allergies according to the receiver operating characteristic curve (P = 0.026). Older age group (OR = 24.0, CIs = 1.4-417.8, P = 0.024) and atopic dermatitis (OR = 8.2, CIs = 1.4-49.8, P = 0.015) were correlated with delayed drug hypersensitivities.

CONCLUSIONS

While several previous studies suggested a higher prevalence of IgE-mediated drug allergies in younger adult females, older boys were more likely to have drug allergies for Chinese children.

Association of Alendronate and Risk of Cardiovascular Events in Patients With Hip Fracture

The risk of cardiovascular events (CVEs) with alendronate use in real-world hip fracture patients is unknown. This study aimed to investigate the risk of CVE with and without use of alendronate in patients with hip fracture. We conducted a retrospective cohort study using a population-wide database managed by the Hong Kong Hospital Authority. Patients newly diagnosed with hip fracture from 2005 through 2013 were followed until November 6, 2016. Alendronate and other antiosteoporosis medications use during the study period were examined. We matched treated and nontreated patients based on time-dependent propensity score. The risks of cardiovascular mortality, myocardial infarction, and stroke between treatment groups were evaluated using conditional Cox regression stratified by match pairs. To examine the associations over time, outcomes were assessed at 1 year, 3 years, 5 years, and 10 years. Among 34,991 patients with newly diagnosed hip fracture, 4602 (13.2%) received antiosteoporosis treatment during follow-up. Physical functioning or survival prospect was not significantly different between treated and nontreated patients. A total of 4594 treated patients were matched with 13,568 nontreated patients. Results of Cox regression analysis revealed that alendronate was associated with a significantly lower risk of 1-year cardiovascular mortality (HR 0.33; 95% CI, 0.17 to 0.65) and incident myocardial infarction (HR 0.55; 95% CI, 0.34 to 0.89), whereas marginally significant reduction in risk of stroke was observed at 5 years and 10 years (HR at 5 years: 0.82; 95% CI, 0.67 to 1.00; p = 0.049; HR at 10 years: 0.83; 95% CI, 0.69 to 1.01; p = 0.065). The strength of the association declined over time but remained significant. Similar results were observed when all nitrogen-containing bisphosphonates (N-BPs) were analyzed together. These findings were robust in multiple sensitivity analyses. Additional studies in other population samples and randomized clinical trials may be warranted to further understand the relationship between use of various antiosteoporosis medication and risk of CVE in patients with hip fracture. © 2018 American Society for Bone and Mineral Research.

Applying a common data model to Asian databases for multinational pharmacoepidemiologic studies: opportunities and challenges

Objective

The goal of the Asian Pharmacoepidemiology Network is to study the effectiveness and safety of medications commonly used in Asia using databases from individual Asian countries. An efficient infrastructure to support multinational pharmacoepidemiologic studies is critical to this effort.

Study design and setting

We converted data from the Japan Medical Data Center database, Taiwan’s National Health Insurance Research Database, Hong Kong’s Clinical Data Analysis and Reporting System, South Korea’s Ajou University School of Medicine database, and the US Medicare 5% sample to the Observational Medical Outcome Partnership common data model (CDM).

Results

We completed and documented the process for the CDM conversion. The coordinating center and participating sites reviewed the documents and refined the conversions based on the comments. The time required to convert data to the CDM varied widely across sites and included conversion to standard terminology codes and refinements of the conversion based on reviews. We mapped 97.2%, 86.7%, 92.6%, and 80.1% of domestic drug codes from the USA, Taiwan, Hong Kong, and Korea to RxNorm, respectively. The mapping rate from Japanese domestic drug codes to RxNorm (70.7%) was lower than from other countries, and we mapped remaining unmapped drugs to Anatomical Therapeutic Chemical Classification System codes. Because the native databases used international procedure coding systems for which mapping tables have been established, we were able to map >90% of diagnosis and procedure codes to standard terminology codes.

Conclusion

The CDM established the foundation and reinforced collaboration for multinational pharmacoepidemiologic studies in Asia. Mapping of terminology codes was the greatest challenge, because of differences in health systems, cultures, and coding systems.

Proton pump inhibitors and risk of Clostridium difficile infection: a multi-country study using sequence symmetry analysis

OBJECTIVE

To determine the association between incident proton pump inhibitor (PPI) use and Clostridium difficile infections across multiple countries Method: National data covering the total population in Australia and Korea, the Canadian population over 65 years and a 3 million person random sample data set from Taiwan were assessed, as were data from a worker insurance population and a hospital inpatient/outpatient population in Japan. Sequence symmetry analysis was used to assess the association with oral vancomycin dispensing as the outcome of interest.

RESULTS

54,957 patients were included. Positive associations were observed in Australia; adjusted sequence ratio (ASR) 2.48 (95% CI 1.90, 3.12), Korea ASR 2.15 (95%CI 2.11, 2.19), Canada ASR 1.45 (95% CI 1.16, 1.79), Japan hospital dataset ASR 3.21 (95%CI 2.12, 4.55) and Japan worker insurance dataset ASR 5.40 (95% CI 2.73, 8.75). The pooled result was ASR 2.40 (95%CI 1.88, 3.05) and 3.16 (95%CI 1.95, 5.10) when limited to Japan, Korean and Taiwan. Results did not vary by individual PPI. The temporal analysis showed effects within the first two weeks of PPI initiation.

CONCLUSION

Our study confirms the association between PPI initiation and C. difficile infections across countries in the Asia-Pacific region.

How valid are IMS DA summary statistics of children's vaccination status?

PURPOSE

Accurate recording of immunization status is essential for the evaluation of any immunization programme. In September 2006, 7-valent pneumococcal conjugate vaccination (PCV7) was introduced into the UK's routine childhood immunization programme. This study validated the PCV7 immunization status of children aged 2 years recorded in the IMS Disease Analyses (DA) database.

METHODS

The PCV7 vaccination uptake rate for children born in 2008 in the IMS DA database was calculated. A sample of 173 of the 2497 children not recorded as vaccinated was identified, and a questionnaire was sent to each of their general practitioners to ascertain the child's true PCV7 vaccination status.

RESULTS

In the IMS DA data of 15 237 children born in 2008, 12 740 (83.6%) had a vaccination record of PCV7. One-hundred and eleven of the 167 questionnaires sent to the child's general practitioners were returned, giving an adjusted response rate of 111/167 (66.5%). Based on the general practitioners' responses, 71 (64%) of these children were fully vaccinated according to their general practitioner's records making the revised estimated vaccination rate for this cohort 94.1% CONCLUSION: This validation study has shown that caution is needed if using historical IMS patient-level data to analyse the effectiveness of PCV7 as there is a potential under-recording of immunization leading to under representation of vaccination rates by approximately 10%. Copyright © 2016 John Wiley & Sons, Ltd.

A pharmacoepidemiologic study of factors influencing the outcome of treatment with lamotrigine in chronic epilepsy

PURPOSE

To identify prognostic factors for freedom from seizures and long-term retention of treatment in patients receiving lamotrigine (LTG).

METHODS

A multicenter, retrospective, case record study of 1,050 patients with chronic epilepsy was carried out. Logistic regression and Cox regression analyses were used to identify clinical features associated with freedom from seizures and retention of treatment, respectively. Long-term retention rates of LTG therapy were estimated using Kaplan-Meier survival analysis.

RESULTS

The 1,050 patients with chronic epilepsy were included in the study. Patients with generalized epilepsy (p = 0.01), who were not receiving carbamazepine (CBZ; p = 0.02) were more likely to become seizure-free. Sixty percent of patients continued on LTG therapy >1 year and estimated retention at 8 years was 38%. Patients with generalized epilepsy (p = 0.002), patients receiving concurrent sodium valproate (VPA; p < 0.0001), those not previously exposed to gabapentin and vigabatrin (p < 0.0001), and those in whom the starting dose was lower (p < 0.0012), were more likely to remain on long-term treatment with LTG. The relationships with exposure to other antiepileptic drugs remained significant in patients with focal and with generalized epilepsy when considered separately.

CONCLUSIONS

The best results from LTG treatment in terms of freedom from seizures and long-term retention of treatment were obtained in patients with generalized epilepsy. Retention of treatment was enhanced by VPA not only in generalized but also in focal epilepsy. The importance of a low starting dose of LTG was again confirmed. The apparent negative effect of CBZ in patients taking LTG merits further investigation.

Adverse event monitoring in lamotrigine patients: a pharmacoepidemiologic study in the United Kingdom

PURPOSE

This postmarketing surveillance study of lamotrigine (LTG) was performed to provide complementary data to large-scale Prescription-Event Monitoring study with a retrospective case records survey in five tertiary referral epilepsy centres in the United Kingdom.

METHODS

Adverse events were recorded and compared with those of two other new antiepileptic drugs (AEDs), gabapentin (GBP) and vigabatrin (VGB). All deaths were followed up and standardised mortality ratios (SMRs) were calculated. Serious adverse events were assessed individually.

RESULTS

A total of 2,701 patients was identified as being exposed to LTG and/or the comparators. It was necessary to exclude 1,326 patients because LTG and/or comparators had been commenced outside the study centres. The adverse events with LTG reported by this study were similar to those reported in the literature. Skin rash was the major adverse event. Life-threatening hepatic failure, acute exacerbation of ulcerative colitis, disseminated intravascular coagulation, and renal failure were reported. No death could be directly attributed to the use of LTG. The SMR was slightly higher than that reported in the literature; this probably reflects severity of epilepsy in the study population.

CONCLUSIONS

The safety profile of LTG was similar to that in the large-scale Prescription-Event Monitoring study and generally acceptable. Life-threatening adverse reactions were rare.

Long-term retention rates of lamotrigine, gabapentin, and topiramate in chronic epilepsy

PURPOSE

We sought to determine the long-term retention rates of lamotrigine (LTG), gabapentin (GBP), and topiramate (TPM) therapy for patients at a tertiary referral clinic for chronic, refractory epilepsy.

METHODS

We analyzed 424 consecutive patients with chronic, refractory partial and/or generalized epilepsy who were started on LTG, 158 patients who were started on GBP, and 393 patients who were started on TPM. The percentages of patients who continued therapy with LTG, GBP, and TPM were estimated with the use of Kaplan-Meier survival analysis. Factors that influence retention were analyzed with the use of Cox regression analysis.

RESULTS

Kaplan-Meier survival analysis showed that at 3 years, 30% continued therapy on TPM compared with 29% on LTG and fewer than 10% on GBP. Adverse events resulted in therapy withdrawal in 40% of patients on TPM compared with GBP (37%) and LTG (22%). Perceived lack of efficacy led to treatment withdrawal in 39% of patients on GBP compared with 34% on LTG and 19% on TPM. Cox regression estimated that a fourth or fewer of patients with chronic partial epilepsy are likely to continue therapy with a new antiepileptic drug beyond 5 years.

CONCLUSIONS

The impact of these new antiepileptic drugs on the long-term course of chronic partial epilepsy is likely to be small, as approximately three of four patients will discontinue therapy. More patients appear to continue on TPM compared with LTG or GBP, with a possible reason being better perceived efficacy of TPM, despite having the highest incidence of adverse events.

A survey on factors that could affect adverse drug reaction reporting according to hospital pharmacists in Great Britain

INTRODUCTION

Since April 1997, UK hospital pharmacists have been invited to submit reports of suspected adverse drug reactions (ADRs) to the Committee on Safety of Medicines (CSM) and Medicines Control Agency. Three studies have investigated the involvement of hospital pharmacists in ADR reporting; however, they did not investigate the possible factors that could affect ADR reporting.

OBJECTIVES

(i) To analyse the extent to which hospital pharmacists think that specified factors could affect reporting ADRs; (ii) to identify any additional factors that could hinder reporting; and (iii) to recommend possible methods to improve reporting.

METHODS

Piloted questionnaires were sent to 548 hospital pharmacists in Great Britain randomly selected by the Royal Pharmaceutical Society of Great Britain (RPSGB) from their computer database. 346 questionnaires were returned and 280 were included in this study.

RESULTS

46% of the pharmacists had identified ADRs that were considered to be reportable according to the CSM criteria in the 6 months prior to the survey. 39% did not report these ADRs either to the CSM or the manufacturers. Only 8.2% reported that their hospitals had a written policy; conversely, 73.7% agreed that such a policy could enhance ADR reporting. Although not statistically significant, the result showed an increasing tendency to report ADRs by pharmacists who had received training. Furthermore, there was an increasing tendency to report ADRs with increasing seniority.

DISCUSSION

The results show that hospital pharmacists say they are more likely to report serious and rare ADRs and ADRs associated with newly marketed drugs. Factors that could reduce ADR reporting included being busy at work, lack of confidence in recognising ADRs and the fear of breaching patient confidentiality. Most common suggestions on methods to improve ADR reporting were to provide ADR training and meetings (34%) and a hospital written policy (24%).

RECOMMENDATIONS

ADR training and meetings would be a useful step in improving hospital pharmacist ADR reporting. Therefore, we recommend that the CSM and the RPSGB liaise with regional drug information centres and schools of pharmacy to provide more study days and training programmes for hospital pharmacists. Furthermore, the CSM should write to the 'Drugs and Therapeutics Committee' of each hospital and encourage them to develop a written local policy for pharmacist ADR reporting. Further studies should be conducted to test the recommendations noted here, assessing the response of the pharmacists in terms of absolute numbers of reports made. It would be particularly interesting to study the need for a written hospital policy and education.

Adverse reactions to new anticonvulsant drugs

A lack of systematic pharmacoepidemiological studies investigating adverse drug reactions (ADRs) to anticonvulsants makes it difficult to assess accurately the incidence of anticonvulsant-related ADRs. Most of the available information in this regard stems from clinical trial experience, case reports and postmarketing surveillance, sources that are not, by any means, structured to provide precise data on adverse event epidemiology. For various ethical, statistical and logistical reasons, the organisation of structured clinical trials that are likely to provide substantial data on ADRs is extremely difficult. This review concentrates on current literature concerning serious and life-threatening ADRs. As with the older anticonvulsants, the majority of ADRs to newer anticonvulsants are CNS-related, although there are several that are apparently unique to some of these new drugs. Gabapentin has been reported to cause aggravation of seizures, movement disorders and psychiatric disturbances. Felbamate should only be prescribed under close medical supervision because of aplastic anaemia and hepatotoxicity. Lamotrigine causes hypersensitivity reactions that range from simple morbilliform rashes to multi-organ failure. Psychiatric ADRs and deterioration of seizure control have also been reported with lamotrigine treatment. Oxcarbazepine has a safety profile similar to that of carbamazepine. Hyponatraemia associated with oxcarbazepine is also a problem; however, it is less likely to cause rash than carbamazepine. Nonconvulsive status epilepticus has been reported frequently with tiagabine, although there are insufficient data at present to identify risk factors for this ADR. Topiramate frequently causes cognitive ADRs and, in addition, also appears to cause word-finding difficulties, renal calculi and bodyweight loss. Vigabatrin has been reported to cause seizure aggravation, especially in myoclonic seizures. There have been rare reports of other neurological ADRs to vigabatrin, such as encephalopathy, aphasia and motor disturbances. Vigabatrin-induced visual field constriction is the latest and most worrying ADR. Many questions regarding the nature of this potentially serious ADR remain unanswered, as no prospective controlled study examining the phenomenon has been published. Rare cases of behavioural ADRs and IgA and IgG2 deficiency associated with the use of zonisamide have been reported. However, relatively few patients so far have been exposed to this drug, and therefore more postmarketing information is required. The relatively late establishment of aplastic anaemia and hepatic failure as potentially fatal ADRs of felbamate, and of visual field constriction with vigabatrin, should serve as ample reminders that ADRs can appear at any time.

Prognostic factors affecting long-term retention of topiramate in patients with chronic epilepsy

PURPOSE

To determine the long-term retention rate of topiramate (TPM) therapy in patients with chronic epilepsy and to identify the relevant prognostic factors that influence retention.

METHODS

All patients with chronic epilepsy (n = 393) prescribed TPM between October 1, 1995, and December 31, 1998, at a tertiary referral centre for epilepsy were analysed. The retention rate for TPM was calculated by using Kaplan-Meier survival analysis, and the prognostic factors influencing retention were analysed by using Cox regression.

RESULTS

Of patients prescribed TPM, 30% continued taking the drug beyond 3 years. Discontinuation was mainly due to adverse events and lack of efficacy. Use of more than one new concurrent antiepileptic drug (AED) and lower maximal daily doses were more likely to result in treatment discontinuation due to adverse events. Older age at onset of epilepsy, a history of having previously taken more than one new AED [lamotrigine (LTG), gabapentin (GBP), or vigabatrin (VGB)], and lower maximal daily doses were more likely to lead to discontinuation due to lack of efficacy.

CONCLUSIONS

A third of patients with chronic epilepsy started on TPM therapy will continue on treatment for >3 years. Absence of learning disabilities, late age at onset of seizures, previous use of more than one new AED, two or more concurrent AED use, and low maximal daily doses of TPM are more likely to result in discontinuation of medication. These factors should be taken into account when considering the use of TPM for the treatment of chronic epilepsy.

The long-term use of gabapentin, lamotrigine, and vigabatrin in patients with chronic epilepsy

PURPOSE

To compare the long-term retention of gabapentin (GBP), lamotrigine (LTG), and vigabatrin (VGB) by patients with chronic epilepsy and the reasons for treatment discontinuation. To assess the likelihood of seizure freedom, seizure-related injury/hospital admission and mortality after these drugs were commenced.

METHODS

This was a retrospective case-records survey in five tertiary referral epilepsy centres in the U.K. The retention times on treatment (from initiation to discontinuation) for the different antiepileptic drugs (AEDs) were compared by using Kaplan-Meier survival analysis and Cox regression. Incidences of seizure freedom and seizure-related injury/hospital admissions and standardised mortality ratios were calculated.

RESULTS

There were 1,375 patients with chronic epilepsy included; 361 were taking GBP, 1,050 LTG, and 713 VGB. The retention of GBP, LTG, or VGB was <40% at 6 years. Fewer than 4% of patients become seizure free while taking one of the drugs. There was no reduction in mortality or seizure-related injury/admission.

CONCLUSIONS

The impact of these new AEDs on chronic epilepsy can be described only as modest. This view may be revised, however, as more experience is gained with new drugs in previously untreated patients.

Factors influencing the incidence of lamotrigine-related skin rash

OBJECTIVE

To determine the incidences of serious and nonserious lamotrigine-related rash, determine the risk factors for lamotrigine-related rash, and evaluate the impact on the incidence of rash of the manufacturer's recommendation to reduce the starting dose of lamotrigine.

METHODS

This was a retrospective case record survey at five tertiary referral epilepsy centers in the UK. The risk factors for lamotrigine-related rash were identified by logistic regression. The independent factors tested were gender, age, epilepsy type, concurrent medication, and starting dose of lamotrigine. The incidences of rash before and after the recommendation of reduction in starting dose were compared by chi2 analysis.

RESULTS

A total of 1050 patients were included. The incidences of serious and nonserious rash were 1.1% (95% CI 0.5% to 1.8%) and 7% (95% CI 5.5% to 8.6%), respectively. Females were at higher risk of developing rash than were males, with a relative risk of 1.8 (95% CI 1.2 to 2.8). The starting dose of lamotrigine was reduced in response to the manufacturer's recommendation, and there was a significant reduction (p = 0.045) in the incidence of serious rash, from 1.5% (12/805) to 0% (0/245). However, there was no reduction in the overall incidence of lamotrigine-related rash, with 63/805 (8%) before and 23/245 (9%) after the recommendation.

CONCLUSIONS

Failure to detect a reduction in the incidence of lamotrigine-related rash since the new (reduced) recommended starting dose of lamotrigine may arise from failure to reduce the starting dose below a critical threshold level, incomplete compliance with current recommendations, or insufficient sample size. The results of this and other studies show that the starting dose of lamotrigine is a significant factor affecting the incidence of rash; furthermore, this study also shows that significant reduction in the incidence of serious rash can be achieved by reducing the starting dose. Therefore, clinicians should not deviate from the recommendations.

Readability of patient information leaflets on antiepileptic drugs in the UK

The Audit Commission in the UK recommends that patient information leaflets (PILs) should be audited by health professionals using a formal readability test. However, no such study on antiepileptic drugs (AEDs) has been identified in a Medline search. The aim of this study was to audit the readability of PILs prepared for marketed proprietary AEDs in the UK. Twelve PILs were compared with six antiepileptic drug articles from medical journals and six headline articles from UK newspapers. The Gunning Fog index and the Flesch Reading Ease index were calculated for each PIL and article. The results of the Gunning Fog index and the Flesch Reading Ease score were compared using the Kruskal-Wallis non-parametric test. PILs were shown to have a statistically significant lower mean reading age than the medical articles and newspapers (P < 0.001). The Gunning Fog index and Flesch Reading Ease score showed that PILs had a mean reading age of 8.8 and mean readability score of 69, respectively. In conclusion, the PILs prepared for proprietary antiepileptic drugs in the UK are suitable for the reading age of the general adult population.

Protective heterologous antiviral immunity and enhanced immunopathogenesis mediated by memory T cell populations

A basic principle of immunology is that prior immunity results in complete protection against a homologous agent. In this study, we show that memory T cells specific to unrelated viruses may alter the host's primary immune response to a second virus. Studies with a panel of heterologous viruses, including lymphocytic choriomeningitis (LCMV), Pichinde (PV), vaccinia (VV), and murine cytomegalo (MCMV) viruses showed that prior immunity with one of these viruses in many cases enhanced clearance of a second unrelated virus early in infection. Such protective immunity was common, but it depended on the virus sequence and was not necessarily reciprocal. Cell transfer studies showed that both CD4 and CD8 T cell populations from LCMV-immune mice were required to transfer protective immunity to naive hosts challenged with PV or VV. In the case of LCMV-immune versus naive mice challenged with VV, there was an enhanced early recruitment of memory phenotype interferon (IFN) gamma-secreting CD4(+) and CD8(+) cells into the peritoneal cavity and increased IFN-gamma levels in this initial site of virus replication. Studies with IFN-gamma receptor knockout mice confirmed a role for IFN-gamma in mediating the protective effect by LCMV-immune T cell populations when mice were challenged with VV but not PV. In some virus sequences memory cell populations, although clearing the challenge virus more rapidly, elicited enhanced IFN-gamma-dependent immunopathogenesis in the form of acute fatty necrosis. These results indicate that how a host responds to an infectious agent is a function of its history of previous infections and their influence on the memory T cell pool.

Interleukin-5 receptor alpha subunit gene regulation in human eosinophil development: identification of a unique cis-element that acts lie an enhancer in regulating activity of the IL-5R alpha promoter

Further functional and biochemical characterization of the nuclear factor(s) which interacts with the EOS1 enhancer-like element in the IL-5R alpha promoter is currently in progress. Since different transcription factors recognize and interact with DNA in distinct fashions and with distinct structural motifs, we have modeled potential binding of the EOS1 factor to its cis-element based upon its methylation interference pattern (Fig. 2), using a cylindrical DNA helical projection (Fig. 6). Over a length of two helical turns, all nuclear protein contacts indicated by methylation interference map to one side of the DNA helix, suggesting that EOS1 binds in the major groove, across the minor groove, and on only one side of the helix. Further review of the model also reveals a potential diad symmetry for the binding site, suggestive of binding by a homodimer and consistent with the formation of the two DNA-protein complexes in our electrophoretic mobility shift experiments that could represent interactions with monomer versus dimer. Comparison of the EOS1 binding motif to similar models for the binding of other transcription factor families for which structural crystallographic and/or binding data is available suggests a similarity of the EOS1 complex to that of the bacterial helix-turn-helix phage lambda and 434 repressor-operator complexes, and the Cys4 zinc finger glucocorticoid response element (GRE) DNA-binding motifs, all of which show similar diad symmetry and binding in the major groove on one side of the DNA. The possibility that EOS1 functions as a GRE is being investigated, especially since there is a consensus AP-1 site at bp -440 to -432 of the IL-5R alpha promoter, immediately adjacent to the EOS1 binding site (see Fig. 5 in reference [36]) and AP-1/GRE interactions have been identified for composite response elements in the regulation of a number of different genes. The identification or cloning of EOS1, a potentially novel and eosinophil lineage-active transcription factor, should enhance our understanding of the processes involved in eosinophil development in particular and myeloid lineage commitment and differentiation in general.

Retrospective study of vigabatrin and psychiatric behavioural disturbances

Vigabatrin (VGB) is an effective add-on anti-epileptic drug. The major serious adverse drug reactions (ADRs) are behavioural and psychiatric disturbances. This study does not support the view that a previous history of behavioural and psychiatric features increases the risk of behavioural/psychiatric ADRs (relative risk 1.23, 95% CI 0.57-2.66, P = 0.61). The results suggest that a low starting does of vigabatrin does not reduce the risk of psychiatric and behavioural ADRs (P = 0.31) or prevent a more overt psychotic reaction from occurring.

Rechallenge with lamotrigine after initial rash

Eight patients rechallenged with lamotrigine after initial exposure which resulted in a skin rash are reported. On reintroduction of the lamotrigine, six of the patients had no recurrence of the rash. Of the other two patients, one had the occurrence of a mild fluctuating and qualitatively different skin rash on rechallenge. The other patient had developed a dose-related rash on initial challenge resulting in a dose reduction. The first attempt to re-increase the dose resulted in reappearance of the rash which again disappeared on dose reduction. However a further attempt to re-increase the dose did not result in reappearance of a rash. It is suggested that patients who experience a rash but good therapeutic response to lamotrigine might be considered for re-dosing.