Validity and interpretation of mortality, health service and survey data on COPD and asthma in England

Impact of pharmacological and non-pharmacological interventions on mortality in chronic obstructive pulmonary disease (COPD) patients

PURPOSE

This review aimed to summarise evidence about the impact of pharmacological and non-pharmacological interventions on survival in COPD patients.

METHODS

We performed a narrative literature review on the effect of pharmacological and non-pharmacological interventions on survival in COPD patients.

RESULTS

Inhaled therapies are central to reduce symptoms in COPD. In particular, inhaled steroids seem to have the greatest effect on mortality. Despite the anti-inflammatory effects attributed to statins, their benefit in COPD has been shown only in cases of combined cardiovascular diseases. The use of beta-blockers in COPD has not been associated with increased COPD-related mortality and a beneficial effect on all-cause mortality has even been shown in COPD patients with cardiovascular diseases. Influenza and pneumococcal vaccination reduced the occurrence of exacerbations and mortality due to COPD. In addition, long-term oxygen therapy (LTOT) (≥15h/day) in COPD patients with severe hypoxemia had a positive effect on survival. Regarding non-pharmacological interventions, it has been demonstrated that smoking cessation, treatment compliance and nutritional supplementation for underweight patients also have a positive effect on survival. Non-invasive ventilation results were dependent on patient PaCO2 levels. In patients with advanced COPD, further prospective studies are needed to know the effect of bronchoscopic lung volume reduction and lung transplant on COPD survival. Regarding lung transplant, a survival benefit in patients with a pre-transplant BODE score of ≥7 has been shown in retrospective studies.

CONCLUSION

Most of the studies did not evaluate survival as the main criteria and further long-term studies on the global management of COPD are required.

Algorithms to identify COPD in health systems with and without access to ICD coding: a systematic review

Background

Chronic obstructive pulmonary disease (COPD) causes significant morbidity and mortality worldwide. Estimation of incidence, prevalence and disease burden through routine insurance data is challenging because of under-diagnosis and under-treatment, particularly for early stage disease in health care systems where outpatient International Classification of Diseases (ICD) diagnoses are not collected. This poses the question of which criteria are commonly applied to identify COPD patients in claims datasets in the absence of ICD diagnoses, and which information can be used as a substitute. The aim of this systematic review is to summarize previously reported methodological approaches for the identification of COPD patients through routine data and to compile potential criteria for the identification of COPD patients if ICD codes are not available.

Methods

A systematic literature review was performed in Medline via PubMed and Google Scholar from January 2000 through October 2018, followed by a manual review of the included studies by at least two independent raters. Study characteristics and all identifying criteria used in the studies were systematically extracted from the publications, categorized, and compiled in evidence tables.

Results

In total, the systematic search yielded 151 publications. After title and abstract screening, 38 publications were included into the systematic assessment. In these studies, the most frequently used (22/38) criteria set to identify COPD patients included ICD codes, hospitalization, and ambulatory visits. Only four out of 38 studies used methods other than ICD coding. In a significant proportion of studies, the age range of the target population (33/38) and hospitalization (30/38) were provided. Ambulatory data were included in 24, physician claims in 22, and pharmaceutical data in 18 studies. Only five studies used spirometry, two used surgery and one used oxygen therapy.

Conclusions

A variety of different criteria is used for the identification of COPD from routine data. The most promising criteria set in data environments where ambulatory diagnosis codes are lacking is the consideration of additional illness-related information with special attention to pharmacotherapy data. Further health services research should focus on the application of more systematic internal and/or external validation approaches.

How to validate a diagnosis recorded in electronic health records

Over the last decades, the adoption of electronic health records (EHR) by health services worldwide has facilitated the construction of large population-based patient databases. These routinely generated longitudinal records have an enormous potential for epidemiological and clinical research [1–3]. EHR contain information on the health of an individual and are an electronic version of a patient's medical history. This contrasts with administrative claims data, whose main purpose is administration of reimbursement of medical services to healthcare providers. Due to the immense size of EHR, they can offer high statistical power and can often be representative of a population. Linkage between different EHR can further improve the completeness of the data. However, the primary raison d’être of most of these EHR is for clinical, administrative or audit purposes, which is a major challenge to their use for health research. Data elements that would be useful for research can therefore be wrongly classified, insufficiently specified or missing. Misclassified data can lead to systematic measurement errors. Missing data can lead to selection bias and counteract the statistical power provided by the magnitude of EHR [4].

Systematic measurement errors in electronic health record databases can lead to large inferential errors. Validation techniques can help determine the degree of these errors and therefore aid in the interpretation of findings.http://ow.ly/iHQ630np4xU

Persistent variations in national asthma mortality, hospital admissions and prevalence by socioeconomic status and region in England

BACKGROUND

The UK-wide National Review of Asthma Deaths sought to identify avoidable factors from the high numbers of deaths, but did not examine variation by socioeconomic status (SES) or region.

METHODS

We used asthma deaths in England over the period 2002-2015 obtained from national deaths registers, summarised by quintiles of Index of Multiple Deprivation (IMD) and Government Office Region. Emergency asthma admissions were obtained from Hospital Episode Statistics for England 2001-2011. The prevalence of asthma was derived from the Health Survey for England 2010. Associations of mortality, admissions and prevalence with IMD quintile and region were estimated cross-sectionally using incidence rate ratios (IRRs) adjusted for age and sex and, where possible, smoking.

RESULTS

Asthma mortality decreased among more deprived groups at younger ages. Among 5-44 year olds, those in the most deprived quintile, mortality was 19% lower than those in the least deprived quintile (IRR 0.81 (95% CI 0.69 to 0.96). In older adults, this pattern was reversed (45-74 years: IRR 1.37 (1.24-1.52), ≥75 years: IRR 1.30 (1.22-1.39)). In 5-44 year olds the inverse trend with asthma mortality contrasted with large positive associations for admissions (IRR 3.34 (3.30-3.38)) and prevalence of severe symptoms (IRR 2.38 (1.70-3.33)). Prevalence trends remained after adjustment for smoking. IRRs for asthma mortality, admissions and prevalence showed significant heterogeneity between English regions.

CONCLUSIONS

Despite asthma mortality, emergency admissions and prevalence decreasing over recent decades, England still experiences significant SES and regional variations. The previously undocumented inverse relation between deprivation and mortality in the young requires further investigation.

Validation of asthma recording in electronic health records: a systematic review

Objective

To describe the methods used to validate asthma diagnoses in electronic health records and summarize the results of the validation studies.

Background

Electronic health records are increasingly being used for research on asthma to inform health services and health policy. Validation of the recording of asthma diagnoses in electronic health records is essential to use these databases for credible epidemiological asthma research.

Methods

We searched EMBASE and MEDLINE databases for studies that validated asthma diagnoses detected in electronic health records up to October 2016. Two reviewers independently assessed the full text against the predetermined inclusion criteria. Key data including author, year, data source, case definitions, reference standard, and validation statistics (including sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) were summarized in two tables.

Results

Thirteen studies met the inclusion criteria. Most studies demonstrated a high validity using at least one case definition (PPV >80%). Ten studies used a manual validation as the reference standard; each had at least one case definition with a PPV of at least 63%, up to 100%. We also found two studies using a second independent database to validate asthma diagnoses. The PPVs of the best performing case definitions ranged from 46% to 58%. We found one study which used a questionnaire as the reference standard to validate a database case definition; the PPV of the case definition algorithm in this study was 89%.

Conclusion

Attaining high PPVs (>80%) is possible using each of the discussed validation methods. Identifying asthma cases in electronic health records is possible with high sensitivity, specificity or PPV, by combining multiple data sources, or by focusing on specific test measures. Studies testing a range of case definitions show wide variation in the validity of each definition, suggesting this may be important for obtaining asthma definitions with optimal validity.

Years of life lost due to bronchial asthma in Poland between 1999 and 2013

OBJECTIVE

The aim of this study was to analyze the years of life lost due to asthma in Poland between 1999 and 2013, with the use of the SEYLL measure (Standard Expected Years of Life Lost).

METHODS

The study was based on a dataset of 5,606,516 records gathered from death certificates of Polish residents from 1999 to 2013. The data on the deaths due to bronchial asthma and status asthmaticus (J45 and J46 according to ICD-10) were used for the analysis. The SEYLL, SEYLL_p (SEYLL per person) and SEYLL_d (SEYLL per death) were implemented to assess lost life years. The analysis of time trends was performed with the use of the join point model.

RESULTS

In 1999-2013, asthma and status asthmaticus were the cause of 11,380 deaths of Poles (0.20% of all deaths), resulting in 4.23 prematurely lost life years per 10,000 males and 3.22 years per 10,000 females. Over the analyzed years, the value of SEYLL decreased both for men and women. Every man who died due to bronchial asthma in Poland in the studied period, lost on average 19.12 years of life, and every woman 18.20 years.

CONCLUSIONS

The analysis of SEYLL indicated that premature mortality due to asthma is still a meaningful problem in the Polish population and a constant challenge for public health activities.

Investigating trends in asthma and COPD through multiple data sources: A small area study

This paper investigates trends in asthma and COPD by using multiple data sources to help understanding the relationships between disease prevalence, morbidity and mortality. GP drug prescriptions, hospital admissions, and deaths are analysed at clinical commissioning group (CCG) level in England from August 2010 to March 2011. A Bayesian hierarchical model is used for the analysis, which takes into account the complex space and time dependencies of asthma and COPD, while it is also able to detect unusual areas. Main findings show important discrepancies across the different data sources, reflecting the different groups of patients that are represented. In addition, the detection mechanism that is provided by the model, together with inference on the spatial, and temporal variation, provide a better picture of the respiratory health problem.

How Reliable Are Current Data for Assessing the Actual Prevalence of Chronic Obstructive Pulmonary Disease?

Background

Estimating COPD occurrence is perceived by the scientific community as a matter of increasing interest because of the worldwide diffusion of the disease. We aimed to estimate COPD prevalence by using administrative databases from a city in central Italy for 2002–2006, improving both the sensitivity and the reliability of the estimate.

Methods

Multiple sources were used, integrating the hospital discharge register (HDR), clinical charts, spirometry and the cause-specific mortality register (CMR) in a longitudinal algorithm, to reduce underestimation of COPD prevalence. Prevalence was also estimated on the basis of COPD cases confirmed through spirometry, to correct misclassification. Estimating such prevalence relied on using coefficients of validation, derived as the positive predictive value (PPV) for being an actual COPD case from clinical and spirometric data at the Institute of Clinical Physiology of the National Research Council.

Results

We found that sensitivity of COPD prevalence increased by 37%. The highest estimate (4.43 per 100 residents) was observed in the 5-year period, using a 3-year longitudinal approach and combined data from three sources. We found that 17% of COPD cases were misclassified. The above estimate of COPD prevalence decreased (3.66 per 100 residents) when coefficients of validation were applied. The PPV was 80% for the HDR, 82% for clinical diagnoses and 91% for the CMR.

Conclusions

Adjusting the COPD prevalence for both underestimation and misclassification of the cases makes administrative data more reliable for epidemiological purposes.

Detection of COPD Exacerbations and compliance with patient-reported daily symptom diaries using a smart phone-based information system [corrected]

BACKGROUND

Paper-based diaries and self-report of symptom worsening in COPD may lead to underdetection of exacerbations. Epidemiologically, COPD exacerbations exhibit seasonal patterns peaking at year-end. We examined whether the use of a BlackBerry-based daily symptom diary would detect 95% or more of exacerbations and enable characterization of seasonal differences among them.

METHODS

Fifty participants with GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage I to IV COPD began a community-based study in December 2007. Another 30 began in December 2008. Participants transmitted daily symptom diaries using a BlackBerry. Alerts were triggered when symptom changes, missed diary transmissions, or medical care for a respiratory problem occurred. Participant encounters were initiated if COPD exacerbations were suspected. Participants used their BlackBerrys to report returns to normal breathing.

RESULTS

Participants transmitted 99.9% of 28,514 possible daily diaries. All 191 (2.5/participant-year) COPD exacerbations meeting Anthonisen criteria were detected. During 148 of the 191 exacerbations (78%, 1.97/participant-year), patients were hospitalized and/or ordered prednisone, an antibiotic, or both. Respiratory viruses were detected in 78 of the 191 exacerbations (41%). Those coinciding with a respiratory viral infection averaged 12.0 days, and those without averaged 8.9 days (P < .04), with no difference in Anthonisen score. Respiratory symptom scores before exacerbations and after normal breathing return showed no differences. Exacerbations were more frequent during the Christmas period than the rest of the year but were not more frequent than in the rest of winter alone.

CONCLUSIONS

Smartphone-based collection of COPD symptom diaries enables near-complete identification of exacerbations at inception. Exacerbation rates in the Christmas season do not reach levels that necessitate changes in disease management.

Role of comorbid conditions in asthma hospitalizations in the south of France

BACKGROUND

Reasons for asthma hospitalizations are dynamic and complex. Comorbid conditions are important contributors to most chronic diseases today. We aim to characterize and describe risk factors associated with hospitalizations due to asthma in the Languedoc-Roussillon region (France) in 2009.

METHODS

Programme de Médicalisation des Systèmes d'Information (PMSI) data records from 2009 were sorted using selected International Classification of Diseases (ICD10) codes eliciting three groups of asthma hospitalizations according to acute severity. All available data including demographics, comorbid conditions, past hospitalizations either related or unrelated to asthma, seasonality and distance to medical facilities were used to compare the subjects within the three groups.

RESULTS

One thousand two hundred and eighty-nine hospitalizations due to asthma exacerbation were found, concerning 1122 patients. We observed significant differences within the groups, using univariate analysis, concerning duration of hospitalizations (mean ± SD, 4.9 ± 5.9 days vs 6.4 ± 6.8 vs 15.8 ± 16.8, P < 0.001), deaths (percentage, 0.03% vs 1.50% vs 9.20%, P < 0.001) and numbers of comorbid conditions (0.80 ± 0.95 vs 0.75 ± 0.97 vs 1.74 ± 1.36, P < 0.001). Recurrent admissions for asthma during the period 2006-2008 were significantly more frequent in the more severe group (1.93 ± 3.91 vs 2.56 ± 4.47 vs 2.81 ± 3.97, P = 0.006). In the multivariate model, age and number of comorbid conditions were independently associated with severe hospitalizations and deaths.

CONCLUSIONS

Asthma hospitalizations can be appropriately assessed using PMSI coding databases. In this study, age and the presence of comorbid conditions are the major risk factors for asthma hospitalizations and deaths.

BaySTDetect: detecting unusual temporal patterns in small area data via Bayesian model choice

Space-time modeling of small area data is often used in epidemiology for mapping chronic disease rates and by government statistical agencies for producing local estimates of, for example, unemployment or crime rates. Although there is typically a general temporal trend, which affects all areas similarly, abrupt changes may occur in a particular area, e.g. due to emergence of localized predictors/risk factor(s) or impact of a new policy. Detection of areas with "unusual" temporal patterns is therefore important as a screening tool for further investigations. In this paper, we propose BaySTDetect, a novel detection method for short-time series of small area data using Bayesian model choice between two competing space-time models. The first model is a multiplicative decomposition of the area effect and the temporal effect, assuming one common temporal pattern across the whole study region. The second model estimates the time trends independently for each area. For each area, the posterior probability of belonging to the common trend model is calculated, which is then used to classify the local time trend as unusual or not. Crucial to any detection method, we provide a Bayesian estimate of the false discovery rate (FDR). A comprehensive simulation study has demonstrated the consistent good performance of BaySTDetect in detecting various realistic departure patterns in addition to estimating well the FDR. The proposed method is applied retrospectively to mortality data on chronic obstructive pulmonary disease (COPD) in England and Wales between 1990 and 1997 (a) to test a hypothesis that a government policy increased the diagnosis of COPD and (b) to perform surveillance. While results showed no evidence supporting the hypothesis regarding the policy, an identified unusual district (Tower Hamlets in inner London) was later recognized to have higher than national rates of hospital readmission and mortality due to COPD by the National Health Service, which initiated various local enhanced services to tackle the problem. Our method would have led to an early detection of this local health issue.

The reliability of hospital and pharmaceutical data to assess prevalent cases of chronic obstructive pulmonary disease

Identifying chronic obstructive disease (COPD) cases is required to estimate COPD prevalence, to enroll COPD cohorts and to estimate air pollution health effects. Administrative health data are frequently used to identify COPD cases, though their validity has not been satisfactorily assessed. This paper aims to assess the contribution of pharmaceutical data in detecting COPD cases and to estimate the reliability of hospital/mortality databases in detecting COPD cases. Prevalent COPD cases among 35-plus-year-olds were estimated in four Italian areas in 2006 from hospital/mortality registries and adding pharmaceutical data. Age-specific and age-standardized prevalence rates were calculated in each area. Internal validity of COPD diagnoses from hospital and mortality databases was assessed. Pharmaceutical database was used to confirm the hospital/mortality COPD cases and to examine the selection and misclassification of hospitalized cases. Possible misclassification between COPD and asthma cases was estimated using hospital data. Prevalent COPD cases were 77,098 from hospital/mortality registries, 172,357 when respiratory prescriptions were added. Prevalence ranged from 4.0%-6.7%. Only 22.7% of pharmaceutical COPD cases were hospitalized or died and only 37.2% of hospital/mortality cases consumed respiratory medicines; this last proportion increased to 64.5% among the older cases with a principal diagnosis. COPD cases with a contemporary asthma diagnosis were 3.1%. We found that pharmaceutical data increases COPD prevalence estimates 2.2-2.5 times. Hospitalization does not necessarily indicate COPD severity, COPD as a principal diagnosis confirmed with medicine prescription more likely represented true cases. Misclassification affects asthma cases to greater extent than COPD cases.

The role of patient activation in frequent attendance at primary care: a population-based study of people with chronic disease

OBJECTIVE

This study explores a range of relevant socio-demographic, physical and psychological factors in a unique examination of the risk factors for frequent attendance at primary care. The impact of patient activation for self-management on health service utilisation is of particular interest.

METHODS

A population-based sample of people with chronic disease from Queensland, Australia, was interviewed using computer assisted telephone surveying. Data were collected from a random sample of 1470 people with either diabetes or a cardiovascular condition.

RESULTS

As participants became more activated they were less likely to frequently attend their main health care provider for assistance with their chronic condition. For both conditions the association was graduated and for participants with a cardiovascular condition this association remained statistically significant even after controlling for other potentially influential factors such as disease severity, length of time since diagnosis, and psychological distress.

CONCLUSION

Characteristics of the individual, including patient activation and psychological functioning, as well as disease factors contribute to primary care consulting patterns among people with chronic illness.

PRACTICAL IMPLICATIONS

Efforts to improve patient activation for self-management should remain a central element of chronic care.

Which practices are high antibiotic prescribers? A cross-sectional analysis

BACKGROUND

Substantial variation in antibiotic prescribing rates between general practices persists, but remains unexplained at national level.

AIM

To establish the degree of variation in antibiotic prescribing between practices in England and identify the characteristics of practices that prescribe higher volumes of antibiotics.

DESIGN OF STUDY

Cross-sectional study.

SETTING

8057 general practices in England.

METHOD

A dataset was constructed containing data on standardised antibiotic prescribing volumes, practice characteristics, patient morbidity, ethnicity, social deprivation, and Quality and Outcomes Framework achievement (2004-2005). Data were analysed using multiple regression modelling.

RESULTS

There was a twofold difference in standardised antibiotic prescribing volumes between practices in the 10th and 90th centiles of the sample (0.48 versus 0.95 antibiotic prescriptions per antibiotic STAR-PU [Specific Therapeutic group Age-sex weightings-Related Prescribing Unit]). A regression model containing nine variables explained 17.2% of the variance in antibiotic prescribing. Practice location in the north of England was the strongest predictor of high antibiotic prescribing. Practices serving populations with greater morbidity and a higher proportion of white patients prescribed more antibiotics, as did practices with shorter appointments, non-training practices, and practices with higher proportions of GPs who were male, >45 years of age, and qualified outside the UK.

CONCLUSION

Practice and practice population characteristics explained about one-sixth of the variation in antibiotic prescribing nationally. Consultation-level and qualitative studies are needed to help further explain these findings and improve our understanding of this variation.

Does the Relationship Between Neighborhood Socioeconomic Status and Health Outcomes Persist Into Very Old Age? A Population-Based Study

Objective: The purpose of this article is (a) to extend previous research on the relationship between neighborhood socioeconomic status (SES) and health by considering a wide range of health-related measures derived from administrative health care records and (b) to explore whether this relationship persists into old age. Method: The study involved a complete cohort of community-dwelling residents in Winnipeg, Canada, who were 65 years or older in 2004/2005 ( N = 77,930). Health measures were derived from administrative claims data. Census data were used to derive neighborhood-level SES. Results: Multilevel logistic regressions indicated that, relative to individuals living in the most affluent areas, those in the poorest areas had significantly higher odds of having arthritis, diabetes, hypertension, congestive heart failure, ischemic heart disease, chronic obstructive pulmonary disease, depression, and stroke. Significant neighborhood income effects tended to be evident among individuals age 65 to 75 as well as those age 75+. Discussion: A wide range of health conditions among older adults are disproportionately clustered into the poorest areas. Programs and services should be designed to meet the needs of older adults of any age in such neighborhoods.

Socio-spatial inequalities and the distribution of cash benefits to asthmatic children in Norway

Background

Previous research has observed large inequalities in the distribution of welfare benefits. The Norwegian welfare state includes several schemes that give households with children the opportunity to apply for public income support to compensate for expenses related to chronic disease. The aims of this study were to examine the geographic distribution of children receiving compensatory cash benefits because of a chronic asthma condition and to determine whether social or geographic factors account for area variations in uptake independent of the associations with need.

Results

Considerable variation between counties was evident, with rates of benefit uptake ranging from 10.5 recipients per 1,000 children younger than nine years in the highest-ranking county, to 1.5 per 1,000 in the lowest. It is argued that the observed area-level inequalities reflect more than variations in morbidity. In particular, the chance of receiving benefits reflects variations in the ability of street-level bureaucrats to inform families about their rights. Spatial variations also reflect, in part, the fact that families with different socio-economic standing inhabit different locations and that the threshold for receiving benefits is systematically lower for families with an academic background.

Conclusion

To be able to refine the implementation of a welfare policy, a better understanding of the processes that generate the outcomes of the various welfare schemes and services is required. This can be achieved by adopting an approach to the study of outcomes of welfare policy that integrates both the social and geographic perspective, and that focuses on specific diagnoses or distributional procedures.

Health care supply for cataract in Austrian public and private hospitals

PURPOSE

This study aims to explain spatial variability or cataract and cataract surgery in Austria. The effect of the availability of health care services on spatial variation is investigated.

METHODS

A retrospective study, using routine hospital data from all Austrian public and private hospitals. Calculation of age- and gender-standardized hospitalization ratios (SHR) for all 121 Austrian districts. Poisson regression for age-specific relative risks was performed.

RESULTS

The authors found high regional variability between districts and significant differences in the hospitalization rates of cataract disease and extraction between men and women. There was a significant correlation between standardized hospitalization ratios for districts and the availability of hospitals with departments of ophthalmology. There was a significant difference in length of stay for patients with cataract surgery between public and private hospitals.

CONCLUSIONS

Use of routine hospital data in geographic analysis allows large regional studies on health care supply for cataract surgery. Differences in the supply by hospitals between districts depend on the availability of hospitals with departments of ophthalmology. The overall demand for cataract surgery in Austria finds its proper supply in many Austrian regions, but needs further development.

Factors associated with mortality after an asthma admission: a national United Kingdom database analysis

BACKGROUND

Lack of a United Kingdom (UK) fatal asthma registry has resulted in few recent analyses regarding patient characteristics, co-morbidities, and admission type in relation to mortality post an asthma admission. This study aims to report these factors in addition to season of event for the years 2000-2005 to provide data regarding asthma burden in the in-patient hospital setting.

METHODS

Data were analysed from the CHKS database collated from UK National Health Service data providing 70% of in-patient coverage in the UK. Patients with admissions under ICD-10 codes J45 "Asthma" and J46 "acute severe asthma" were included. Codes for associated co-morbidity at time of admission were identified, as well as month of admission and death, age, gender and length of stay.

RESULTS

The mortality rate over the 5-year period was 1063 patients from 250,043 asthma admissions (0.43%). Critical care mortality was far higher and an annual rate indicated that for every 100,000 admissions 2878 (95% CI 2091;3857) patients died. Respiratory infection, cardiovascular disease and diabetes were common co-morbidities for all admissions. December and January had the peak number of deaths post asthma admission which were nearly all in adults, death being rarer in children. Women and those over 45 years had the highest rate of death which may reflect asthma prevalence.

CONCLUSIONS

Co-morbid conditions experienced by older asthma patients may contribute to mortality post an asthma admission and greater understanding of risk factors contributing to fatality are required.

Changing the burden of COPD mortality

COPD is a major cause of mortality and morbidity worldwide with an estimated 2.75 million deaths in 2000 (fourth leading cause of death). In addition to the considerable morbidity and mortality associated with COPD, this disease incurs significant healthcare and societal costs. Current COPD guidelines acknowledge that the following can improve COPD mortality: smoking cessation; long-term oxygen therapy; and lung volume reduction surgery in small subsets of COPD patients. To date, no randomized controlled trials have demonstrated an effect of pharmacological treatment on mortality, although several observational studies suggest that both long-acting bronchodilators and inhaled corticosteroids may provide a survival benefit. The possibility that these treatments reduce mortality is being investigated in ongoing large-scale clinical trials.