Use of the General Practice Research Database (GPRD) for respiratory epidemiology: a comparison with the 4th Morbidity Survey in General Practice (MSGP4)

Program for data extraction in primary health records: a valid tool for knowledge production in general practice?

Objectives

Research in general practice demands it-tools which give the practitioner trusty results. Medrave 4 is a program designed for extraction of data from all areas of the health record. We wanted to do research on the database in a health center, but found no proof of the quality of the data extracted by Medrave 4. Today the database contains about 40,000 records. In this study we wanted to examine if the program could extract correct data.

Results

From the database 20 records were randomly selected from five different time periods, making a total of 100 records. 14 records did not meet the inclusion criteria, resulting in 86 records included in the study. In phase one these variables were registered manually from the records: Age, gender, systolic and diastolic blood pressure (from free text) and six different laboratory tests. In phase two, Medrave 4 extracted the same variables from the same records. Medrave 4 found correct systolic and diastolic blood pressure values in 79 records (92%). The laboratory results were extracted correct in all 86 records (100%). We conclude that Medrave 4 can be a useful tool in quantifying the work of general practitioners.

Cardiovascular Outcomes after a Respiratory Tract Infection among Adults with Non-Cystic Fibrosis Bronchiectasis: A General Population-based Study

RATIONALE

Studies suggest that adults with bronchiectasis are at increased risk of cardiovascular comorbidities.

OBJECTIVES

We aimed to quantify the relative risk of incident cardiovascular events after a respiratory tract infection among adults with bronchiectasis.

METHODS

Using UK electronic primary care records, we conducted a within-person comparison using the self-controlled case series method. We calculated the relative risk of first-time cardiovascular events (either first myocardial infarction or stroke) after a respiratory tract infection compared with the individual's baseline risk.

RESULTS

Our cohort consisted of 895 adult men and women with non-cystic fibrosis bronchiectasis with a first myocardial infarction or stroke and at least one respiratory tract infection. There was an increased rate of first-time cardiovascular events in the 91-day period after a respiratory tract infection (incidence rate ratio, 1.56; 95% confidence interval, 1.20-2.02). The rate of a first cardiovascular event was highest in the first 3 days after a respiratory tract infection (incidence rate ratio, 2.73; 95% confidence interval, 1.41-5.27).

CONCLUSIONS

These data suggest that respiratory tract infections are strongly associated with a transient increased risk of first-time myocardial infarction or stroke among people with bronchiectasis. As respiratory tract infections are six times more common in people with bronchiectasis than the general population, the increased risk has a disproportionately greater impact in these individuals. These findings may have implications for including cardiovascular risk modifications in airway infection treatment pathways in this population.

Incidence, Prevalence, and Survival of Patients with Idiopathic Pulmonary Fibrosis in the UK

Introduction

Recent developments in the care of patients with idiopathic pulmonary fibrosis have the potential to improve survival rates. Population-based estimates of the current disease burden are needed to evaluate the future impact of newly approved therapies. The objective of this study is to describe incidence, prevalence, and survival of idiopathic pulmonary fibrosis patients in the UK.

Methods

Between 2000 and 2012, a patient cohort (N = 9,748,108), identified from Clinical Practice Research Datalink primary care data, was used to identify incident and prevalent cases of idiopathic pulmonary fibrosis–clinical syndrome. Incident cases were followed up to identify deaths. Poisson and Cox regressions were used to calculate incidence rate ratios (IRR) and hazard ratios for mortality, respectively. Adjustments were made for age, gender, and strategic health authority. Survival from diagnosis was estimated using Kaplan–Meier analysis.

Results

In total 1491 and 4527 incident cases were identified using narrow and broad idiopathic pulmonary fibrosis–clinical syndrome definitions, respectively. Incidence and prevalence increased during the study. Compared with 2000, a near 80% increase in incidence was observed by 2012 [IRR 1.78 (95% CI 1.50–2.11; broad definition)], despite an observed decrease using the narrow definition [0.50 (0.38–0.65)]. Median survival was 3.0 years (95% CI 2.8–3.1) and 2.7 years (95% CI 2.5–3.0) in broad (n = 2168) and narrow case sets (n = 996), respectively. No significant changes in survival were observed.

Conclusions

Idiopathic pulmonary fibrosis incidence rates have increased since 2000 and survival remains poor. These results provide a benchmark against which the effects of future treatment changes can be measured.

Funding

InterMune UK and Ireland (now part of F. Hoffman La Roche).

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0693-1) contains supplementary material, which is available to authorized users.

A validation study of the CirCom comorbidity score in an English cirrhosis population using the Clinical Practice Research Datalink

Purpose

The CirCom score has been developed from Danish data as a specific measure of comorbidity for cirrhosis to predict all-cause mortality. We compared its performance with the Charlson Comorbidity Index (CCI) in an English cirrhosis population.

Patients and methods

We used comorbidity scores in a survival model to predict mortality in a cirrhosis cohort in the Clinical Practice Research Datalink. The discrimination of each score was compared by age, gender, socioeconomic status, cirrhosis etiology, cirrhosis stage, and year after cirrhosis diagnosis. We also measured their ability to predict liver-related versus non-liver-related death.

Results

There was a small improvement in the C statistic from the model using the CirCom score (C=0.63) compared to the CCI (C=0.62), and there was an overall improvement in the net reclassification index of 1.5%. The improvement was more notable in younger patients, those with an alcohol etiology, and those with compensated cirrhosis. Both scores performed better (C statistic >0.7) for non-liver-related deaths than liver-related deaths (C statistic <0.6), as comorbidity was only weakly predictive of liver-related death.

Conclusion

The CirCom score provided a small improvement in performance over the CCI in the prediction of all-cause and non-liver mortality, but not liver-related mortality. Therefore, it is important to include a measure of comorbidity in studies of cirrhosis survival, alongside a measure of cirrhosis severity.

Childhood asthma prevalence: cross-sectional record linkage study comparing parent-reported wheeze with general practitioner-recorded asthma diagnoses from primary care electronic health records in Wales

Introduction

Electronic health records (EHRs) are increasingly used to estimate the prevalence of childhood asthma. The relation of these estimates to those obtained from parent-reported wheezing suggestive of asthma is unclear. We hypothesised that parent-reported wheezing would be more prevalent than general practitioner (GP)-recorded asthma diagnoses in preschool-aged children.

Methods

1529 of 1840 (83%) Millennium Cohort Study children registered with GPs in the Welsh Secure Anonymised Information Linkage databank were linked. Prevalences of parent-reported wheezing and GP-recorded asthma diagnoses in the previous 12 months were estimated, respectively, from parent report at ages 3, 5, 7 and 11 years, and from Read codes for asthma diagnoses and prescriptions based on GP EHRs over the same time period. Prevalences were weighted to account for clustered survey design and non-response. Cohen’s kappa statistics were used to assess agreement.

Results

Parent-reported wheezing was more prevalent than GP-recorded asthma diagnoses at 3 and 5 years. Both diminished with age: by age 11, prevalences of parent-reported wheezing and GP-recorded asthma diagnosis were 12.9% (95% CI 10.6 to 15.4) and 10.9% (8.8 to 13.3), respectively (difference: 2% (−0.5 to 4.5)). Other GP-recorded respiratory diagnoses accounted for 45.7% (95% CI 37.7 to 53.9) and 44.8% (33.9 to 56.2) of the excess in parent-reported wheezing at ages 3 and 5 years, respectively.

Conclusion

Parent-reported wheezing is more prevalent than GP-recorded asthma diagnoses in the preschool years, and this difference diminishes in primary school-aged children. Further research is needed to evaluate the implications of these differences for the characterisation of longitudinal childhood asthma phenotypes from EHRs.

Comparative Effectiveness of Step-up Therapies in Children with Asthma Prescribed Inhaled Corticosteroids: A Historical Cohort Study

BACKGROUND

In children with uncontrolled asthma prescribed low-dose inhaled corticosteroids (ICSs), various step-up options are available: fixed-dose combination ICS/long-acting β₂-agonist (FDC), increasing ICS dose, or adding leukotriene receptor antagonist (LTRA). However, evidence of their relative effectiveness is limited.

OBJECTIVE

To compare the effectiveness of step-up treatment to FDC in children with asthma versus increased ICS dose, or LTRA.

METHODS

This matched cohort study used UK primary-care databases to study children prescribed their first step-up treatment to FDC, increased ICS dose, or LTRA. A year of baseline data was used for matching and identifying confounders. Outcomes over the following year were examined. The primary outcome was severe exacerbation rate; secondary outcomes included overall asthma control, derived from databases (no asthma-related admissions/hospital attendances/oral corticosteroids or antibiotics prescribed with a respiratory review, and average prescribed salbutamol ≤200 μg/day).

RESULTS

There were 971 matched pairs in the FDC and increased ICS dose cohorts (59% males; mean age, 9.4 years) and 785 in the FDC and LTRA cohorts (60% males; mean age, 9.0 years). Exacerbation rates in the outcome year were similar between FDC and increased ICS (adjusted incidence rate ratio [95% CI], 1.09 [0.75-1.59]) and FDC and LTRA (incidence rate ratio, 1.36 [0.93-2.01]). Increased ICS and LTRA significantly reduced the odds of achieving overall asthma control, compared with FDC (odds ratios [95% CI], 0.52 [0.42-0.64] and 0.53 [0.42-0.66], respectively)-this was driven by reduced short-acting beta-agonist use.

CONCLUSIONS

FDC is as effective as increased ICS or LTRA in reducing severe exacerbation rate, but more effective in achieving asthma control.

The Use of a Bayesian Hierarchy to Develop and Validate a Co-Morbidity Score to Predict Mortality for Linked Primary and Secondary Care Data from the NHS in England

Background

We have assessed whether the linkage between routine primary and secondary care records provided an opportunity to develop an improved population based co-morbidity score with the combined information on co-morbidities from both health care settings.

Methods

We extracted all people older than 20 years at the start of 2005 within the linkage between the Hospital Episodes Statistics, Clinical Practice Research Datalink, and Office for National Statistics death register in England. A random 50% sample was used to identify relevant diagnostic codes using a Bayesian hierarchy to share information between similar Read and ICD 10 code groupings. Internal validation of the score was performed in the remaining 50% and discrimination was assessed using Harrell’s C statistic. Comparisons were made over time, age, and consultation rate with the Charlson and Elixhauser indexes.

Results

657,264 people were followed up from the 1st January 2005. 98 groupings of codes were derived from the Bayesian hierarchy, and 37 had an adjusted weighting of greater than zero in the Cox proportional hazards model. 11 of these groupings had a different weighting dependent on whether they were coded from hospital or primary care. The C statistic reduced from 0.88 (95% confidence interval 0.88–0.88) in the first year of follow up, to 0.85 (0.85–0.85) including all 5 years. When we stratified the linked score by consultation rate the association with mortality remained consistent, but there was a significant interaction with age, with improved discrimination and fit in those under 50 years old (C = 0.85, 0.83–0.87) compared to the Charlson (C = 0.79, 0.77–0.82) or Elixhauser index (C = 0.81, 0.79–0.83).

Conclusions

The use of linked population based primary and secondary care data developed a co-morbidity score that had improved discrimination, particularly in younger age groups, and had a greater effect when adjusting for co-morbidity than existing scores.

Vitamin D supplementation during pregnancy and infancy reduces aeroallergen sensitization: a randomized controlled trial

BACKGROUND

Vitamin D has immune-modulating effects. We determined whether vitamin D supplementation during pregnancy and infancy prevents aeroallergen sensitization and primary care respiratory illness presentations.

METHODS

A randomized, double-blind, placebo-controlled parallel-group trial. We assigned pregnant women, from 27-week gestation to birth, and then their infants, from birth to 6 months, to placebo or one of two dosages of daily oral vitamin D. Woman/infant pairs were randomized to: placebo/placebo, 1000 IU/400 IU or 2000 IU/800 IU. When the children were 18 months old, we measured serum-specific IgE antibodies and identified acute primary care visits described by the doctor to be due to a cold, otitis media, an upper respiratory infection, croup, asthma, bronchitis, bronchiolitis, a wheezy lower respiratory infection or fever and cough.

RESULTS

Specific IgE was measured on 185 of 260 (71%) enrolled children. The proportion of children sensitized differed by study group for four mite antigens: Dermatophagoides farinae (Der-f1, Der-f2) and Dermatophagoides pteronyssinus (Der-p1, Der-p2). With results presented for placebo, lower dose, and higher dose vitamin D, respectively (all P < 0.05): Der-f1 (18%, 10%, 2%), Der-f2 (14%, 3%, 2%), Der-p1 (19%, 14%, 3%) and Der-p2 (12%, 2%, 3%). There were study group differences in the proportion of children with primary care visits described by the doctor as being for asthma (11%, 0%, 4%, P = 0.002), but not for the other respiratory diagnoses.

CONCLUSIONS

Vitamin D supplementation during pregnancy and infancy reduces the proportion of children sensitized to mites at age 18 months. Preliminary data indicate a possible effect on primary care visits where asthma is diagnosed.

Bronchiectasis and the risk of cardiovascular disease: a population-based study

BACKGROUND

There are limited data on the burden of cardiovascular comorbidities in people with bronchiectasis. Our cross-sectional study estimates the burden of pre-existing diagnoses of coronary heart disease (CHD) and stroke in people with bronchiectasis compared with the general population. The historical cohort study investigates if individuals with bronchiectasis are at increased risk of incident CHD and stroke events.

METHODS

We used primary care electronic records from the Clinical Practice Research Datalink. The cross-sectional study used logistic regression to quantify the association between bronchiectasis and recorded diagnoses of CHD or stroke. Cox regression was used to investigate if people with bronchiectasis experienced increased incident CHD and strokes compared with the general population, adjusting for age, sex, smoking habit and other risk factors for cardiovascular disease.

RESULTS

Pre-existing diagnoses of CHD (OR 1.33, 95% CI 1.25 to 1.41) and stroke (OR 1.92, 95% CI 1.85 to 2.01) were higher in people with bronchiectasis compared with those without bronchiectasis, after adjusting for age, sex, smoking and risk factors for cardiovascular disease. The rate of first CHD and stroke were also higher in people with bronchiectasis (HR for CHD 1.44 (95% CI 1.27 to 1.63) and HR for stroke 1.71 (95% CI 1.54 to 1.90)).

CONCLUSION

The risk of CHD and stroke are higher among people with bronchiectasis compared with the general population. An increased awareness of these cardiovascular comorbidities in this population is needed to provide a more integrated approach to the care of these patients.

The risk of community-acquired pneumonia among 9803 patients with coeliac disease compared to the general population: a cohort study

BACKGROUND

Patients with coeliac disease are considered as individuals for whom pneumococcal vaccination is advocated.

AIM

To quantify the risk of community-acquired pneumonia among patients with coeliac disease, assessing whether vaccination against streptococcal pneumonia modified this risk.

METHODS

We identified all patients with coeliac disease within the Clinical Practice Research Datalink linked with English Hospital Episodes Statistics between April 1997 and March 2011 and up to 10 controls per patient with coeliac disease frequency matched in 10-year age bands. Absolute rates of community-acquired pneumonia were calculated for patients with coeliac disease compared to controls stratified by vaccination status and time of diagnosis using Cox regression in terms of adjusted hazard ratios (HR).

RESULTS

Among 9803 patients with coeliac disease and 101 755 controls, respectively, there were 179 and 1864 first community-acquired pneumonia events. Overall absolute rate of pneumonia was similar in patients with coeliac disease and controls: 3.42 and 3.12 per 1000 person-years respectively (HR 1.07, 95% CI 0.91-1.24). However, we found a 28% increased risk of pneumonia in coeliac disease unvaccinated subjects compared to unvaccinated controls (HR 1.28, 95% CI 1.02-1.60). This increased risk was limited to those younger than 65, was highest around the time of diagnosis and was maintained for more than 5 years after diagnosis. Only 26.6% underwent vaccination after their coeliac disease diagnosis.

CONCLUSIONS

Unvaccinated patients with coeliac disease under the age of 65 have an excess risk of community-acquired pneumonia that was not found in vaccinated patients with coeliac disease. As only a minority of patients with coeliac disease are being vaccinated there is a missed opportunity to intervene to protect these patients from pneumonia.

Two-stage Bayesian model to evaluate the effect of air pollution on chronic respiratory diseases using drug prescriptions

Exposure to high levels of air pollutant concentration is known to be associated with respiratory problems which can translate into higher morbidity and mortality rates. The link between air pollution and population health has mainly been assessed considering air quality and hospitalisation or mortality data. However, this approach limits the analysis to individuals characterised by severe conditions. In this paper we evaluate the link between air pollution and respiratory diseases using general practice drug prescriptions for chronic respiratory diseases, which allow to draw conclusions based on the general population. We propose a two-stage statistical approach: in the first stage we specify a space-time model to estimate the monthly NO2 concentration integrating several data sources characterised by different spatio-temporal resolution; in the second stage we link the concentration to the β2-agonists prescribed monthly by general practices in England and we model the prescription rates through a small area approach.

Changes in the incidence, prevalence and mortality of bronchiectasis in the UK from 2004 to 2013: a population-based cohort study

There is a paucity of data on incidence, prevalence and mortality associated with non-cystic fibrosis bronchiectasis.Using the Clinical Practice Research Datalink for participants registered between January 1, 2004 and December 31, 2013, we determined incidence, prevalence and mortality associated with bronchiectasis in the UK and investigated changes over time.The incidence and point prevalence of bronchiectasis increased yearly during the study period. Across all age groups, the incidence in women increased from 21.2 per 100 000 person-years in 2004 to 35.2 per 100 000 person-years in 2013 and in men from 18.2 per 100 000 person-years in 2004 to 26.9 per 100 000 person-years in 2013. The point prevalence in women increased from 350.5 per 100 000 in 2004 to 566.1 per 100 000 in 2013 and in men from 301.2 per 100 000 in 2004 to 485.5 per 100 000 in 2013. Comparing morality rates in women and men with bronchiectasis in England and Wales (n=11 862) with mortality rates in the general population from Office of National Statistics data showed that in women the age-adjusted mortality rate for the bronchiectasis population was 1437.7 per 100 000 and for the general population 635.9 per 100 000 (comparative mortality figure of 2.26). In men, the age-adjusted mortality rate for the bronchiectasis population was 1914.6 per 100 000 and for the general population 895.2 per 100 000 (comparative mortality figure of 2.14).Bronchiectasis is surprisingly common and is increasing in incidence and prevalence in the UK, particularly in older age groups. Bronchiectasis is associated with a markedly increased mortality.

Risk of community-acquired pneumonia in patients with a diagnosis of pernicious anemia: a population-based retrospective cohort study

OBJECTIVE

Pernicious anemia (PA) is an autoimmune disease that causes achlorhydria or profound hypochlorhydria. We conducted a population-based study to determine whether individuals with PA are at an increased risk for community-acquired pneumonia (CAP).

METHODS

We performed a retrospective cohort study using The Health Improvement Network (THIN) from the UK (1993-2009). The eligible study cohort included individuals 18 years of age or older, with at least 1 year of THIN follow-up. The exposed group consisted of individuals with a diagnosis code for PA. The unexposed group consisted of individuals without a diagnosis of PA and was frequency matched with the exposed group with respect to age, sex, and practice site. Cox regression analysis was used to determine the hazard ratio with the 95% confidence interval for CAP associated with PA, accounting for a comprehensive list of potential confounders.

RESULTS

The study included 13,605 individuals with PA and 50,586 non-PA individuals. The crude incidence rate of CAP was 9.4/1000 person-years for those with PA, versus 6.4/1000 person-years for those without PA. The multivariable adjusted hazard ratio for CAP associated with PA was 1.18 (95% confidence interval 1.08-1.29).

CONCLUSION

In this large population-based cohort study, individuals with PA and presumed chronic achlorhydria were at an increased risk for CAP.

Can different primary care databases produce comparable estimates of burden of disease: results of a study exploring venous leg ulceration

BACKGROUND

Primary care databases from the UK have been widely used to produce evidence on the epidemiology and health service usage of a wide range of conditions. To date there have been few evaluations of the comparability of estimates between different sources of these data.

AIM

To estimate the comparability of two widely used primary care databases, the Health Improvement Network Database (THIN) and the General Practice Research Database (GPRD) using venous leg ulceration as an exemplar condition.

DESIGN OF STUDY

Cross prospective cohort comparison.

SETTING

GPRD and the THIN databases using data from 1998 to 2006.

METHOD

A data set was extracted from both databases containing all cases of persons aged 20 years or greater with a database diagnosis of venous leg ulceration recorded in the databases for the period 1998-2006. Annual rates of incidence and prevalence of venous leg ulceration were calculated within each database and standardized to the European standard population and compared using standardized rate ratios.

RESULTS

Comparable estimates of venous leg ulcer incidence from the GPRD and THIN databases could be obtained using data from 2000 to 2006 and of prevalence using data from 2001 to 2006.

CONCLUSIONS

Recent data collected by these two databases are more likely to produce comparable results of the burden venous leg ulceration. These results require confirmation in other disease areas to enable researchers to have confidence in the comparability of findings from these two widely used primary care research resources.

Small-particle Inhaled Corticosteroid as First-line or Step-up Controller Therapy in Childhood Asthma

BACKGROUND

Because randomized controlled trials of established pediatric asthma therapies are expensive and difficult to perform, observational studies may fill gaps in the evidence base.

OBJECTIVES

To compare the effectiveness of representative small-particle inhaled corticosteroid (ICS) with that of standard size-particle ICS for children initiating or stepping up ICS therapy for asthma (analysis 1) and to compare the effectiveness of ICS dose step-up using small-particle ICS with adding long-acting β2-agonist (LABA) to the ICS (analysis 2).

METHODS

These historical matched cohort analyses drew on electronic medical records of children with asthma aged 5 to 11 years. Variables measured during 2 consecutive years (1 baseline year for confounder definition and 1 outcome year) included risk-domain asthma control (no hospital attendance for asthma, acute oral corticosteroids, or lower respiratory tract infection requiring antibiotics) and rate of severe exacerbations (asthma-related emergency, hospitalization, or oral corticosteroids).

RESULTS

In the initiation population (n = 797 in each cohort), children prescribed small-particle ICS versus standard size-particle ICS experienced greater odds of asthma control (adjusted odds ratio, 1.49; 95% CI, 1.10-2.02) and lower severe exacerbation rate (adjusted rate ratio, 0.56; 95% CI, 0.35-0.88). Step-up outcomes (n = 206 in each cohort) were also significantly better for small-particle ICS, with asthma control adjusted odds ratio of 2.22 (95% CI, 1.23-4.03) and exacerbations adjusted rate ratio of 0.49 (95% CI, 0.27-0.89). The number needed to treat with small-particle ICS to achieve 1 additional child with asthma control was 17 (95% CI, 9-107) for the initiation population and 5 (95% CI, 3-78) for the step-up population. Outcomes were not significantly different for stepped-up small-particle ICS dose versus ICS/LABA combination (n = 185 in each cohort).

CONCLUSIONS

Initiating or stepping up the ICS dose with small-particle ICS rather than with standard size-particle ICS is more effective and shows similar effectiveness to add-on LABA in childhood asthma.

Adherence-adjusted estimates of benefits and harms from treatment with amoxicillin for LRTI: secondary analysis of a 12-country randomised placebo-controlled trial using randomisation-based efficacy estimators

OBJECTIVES

Estimate the efficacy of amoxicillin for acute uncomplicated lower-respiratory-tract infection (LRTI) in primary care and demonstrate the use of randomisation-based efficacy estimators.

DESIGN

Secondary analysis of a two-arm individually-randomised placebo-controlled trial.

SETTING

Primary care practices in 12 European countries.

PARTICIPANTS

Patients aged 18 or older consulting with an acute LRTI in whom pneumonia was not suspected by the clinician.

INTERVENTIONS

Amoxicillin (two 500 mg tablets three times a day for 7 days) or matched placebo.

MAIN OUTCOME MEASURES

Clinician-rated symptom severity between days 2-4; new/worsening symptoms and presence of side effects at 4-weeks. Adherence was captured using self-report and tablet counts.

RESULTS

2061 participants were randomised to the amoxicillin or placebo group. On average, 88% of the prescribed amoxicillin was taken. The original analysis demonstrated small increases in both benefits and harms from amoxicillin. Minor improvements in the benefits of amoxicillin were observed when an adjustments for adherence were made (mean difference in symptom severity -0.08, 95% CI -0.17 to 0.01, OR for new/worsening symptoms 0.81, 95% CI 0.66 to 0.98) as well as minor increases in harms (OR for side effects 1.32, 95% CI 1.12 to 1.57).

CONCLUSIONS

Adherence to amoxicillin was high, and the findings from the original analysis were robust to non-adherence. Participants consulting to primary care with an acute uncomplicated LRTI can on average expect minor improvements in outcome from taking amoxicillin. However, they are also at an increased risk of experiencing side effects.

TRIAL REGISTRATION NUMBERS

Eudract-CT 2007-001586-15 and ISRCTN52261229. The trial was registered at EudraCT in 2007 due to an administrative misunderstanding that EudraCT was a suitable registry--which it was not in 2007, but has become since. On discovery of this error, the trial was also registered at ISRCTN (January 2009). Trial procedures did not change between the two registrations.

Application of multicategory exposure marginal structural models to investigate the association between long-acting beta-agonists and prescribing of oral corticosteroids for asthma exacerbations in the Clinical Practice Research Datalink

OBJECTIVE

To examine the comparative effectiveness of inhaled long-acting beta-agonist (LABA), inhaled corticosteroid (ICS), and ICS/LABA combinations.

METHODS

We used a retrospective cohort design of patients older than 12 years with asthma diagnosis in the Clinical Practice Research Datalink to evaluate asthma-related morbidity measured by oral corticosteroid (OCS) initiation within 12 months of initiating LABAs, ICSs, or ICSs/LABAs. Asthma severity 12 months before drug initiation (use of OCSs, asthma-related hospital or emergency department visits, and number of short-acting beta-agonist prescriptions) and during follow-up (short-acting beta-agonist prescriptions and total number of asthma drug classes) was adjusted as a time-varying variable via marginal structural models.

RESULTS

A total of 51,103 patients with asthma were followed for 12 months after receiving first prescription for study drugs from 1993 to 2010. About 92% initiated ICSs, 1% initiated LABAs, and 7% initiated ICSs/LABAs. Compared with ICSs, LABAs were associated with a 10% increased risk of asthma exacerbations requiring short courses of OCSs (hazard ratio [HR] 1.10; 95% confidence interval [CI] 1.07-1.18). ICS/LABA initiators were 62% less likely than ICS initiators (HR 0.38; 95% CI 0.12-0.66) and 50% less likely than LABA initiators to receive OCS prescriptions for asthma exacerbations (HR 0.50; 95% CI 0.14-0.78).

CONCLUSIONS

In concordance with current asthma management guidelines, inhaled LABAs should not be prescribed as monotherapy to patients with asthma. The findings suggest the presence of time-dependent confounding by asthma severity, which was accounted for by the marginal structural model.

Using an electronic medical record (EMR) to conduct clinical trials: Salford Lung Study feasibility

Background

Real-world data on the benefit/risk profile of medicines is needed, particularly in patients who are ineligible for randomised controlled trials conducted for registration purposes. This paper describes the methodology and source data verification which enables the conduct of pre-licensing clinical trials of COPD and asthma in the community using the electronic medical record (EMR), NorthWest EHealth linked database (NWEH-LDB) and alert systems.

Methods

Dual verification of extracts into NWEH-LDB was performed using two independent data sources (Salford Integrated Record [SIR] and Apollo database) from one primary care practice in Salford (N = 3504). A feasibility study was conducted to test the reliability of the NWEH-LDB to support longitudinal data analysis and pragmatic clinical trials in asthma and COPD. This involved a retrospective extraction of data from all registered practices in Salford to identify a cohort of patients with a diagnosis of asthma (aged ≥18) and/or COPD (aged ≥40) and ≥2 prescriptions for inhaled bronchodilators during 2008. Health care resource utilisation (HRU) outcomes during 2009 were assessed. Exacerbations were defined as: prescription for oral corticosteroids (OCS) in asthma and prescription of OCS or antibiotics in COPD; and/or hospitalisation for a respiratory cause.

Results

Dual verification demonstrated consistency between SIR and Apollo data sources: 3453 (98.6%) patients were common to both systems; 99.9% of prescription records were matched and of 29,830 diagnosis records, one record was missing from Apollo and 272 (0.9%) from SIR. Identified COPD patients were also highly concordant (Kappa coefficient = 0.98).

A total of 7981 asthma patients and 4478 COPD patients were identified within the NWEH-LDB. Cohort analyses enumerated the most commonly prescribed respiratory medication classes to be: inhaled corticosteroids (ICS) (42%) and ICS plus long-acting β₂-agonist (LABA) (40%) in asthma; ICS plus LABA (55%) and long-acting muscarinic antagonists (36%) in COPD. During 2009 HRU was greater in the COPD versus asthma cohorts, and exacerbation rates in 2009 were higher in patients who had ≥2 exacerbations versus ≤1 exacerbation in 2008 for both asthma (137.5 vs. 20.3 per 100 person-years, respectively) and COPD (144.6 vs. 41.0, respectively).

Conclusion

Apollo and SIR data extracts into NWEH-LDB showed a high level of concordance for asthma and COPD patients. Longitudinal data analysis characterized the COPD and asthma populations in Salford including medications prescribed and health care utilisation outcomes suitable for clinical trial planning.

Responsiveness of primary care services: development of a patient-report measure – qualitative study and initial quantitative pilot testing

Background

Primary care service providers do not always respond to the needs of diverse groups of patients, and so certain patients groups are disadvantaged. General practitioner (GP) practices are increasingly encouraged to be more responsive to patients’ needs in order to address inequalities.

Objectives

(1) Explore the meaning of responsiveness in primary care. (2) Develop a patient-report questionnaire for use as a measure of patient experience of responsiveness by a range of primary care organisations (PCOs). (3) Investigate methods of population mapping available to GP practices.

Design setting

PCOs, including GP practices, walk-in centres and community pharmacies.

Participants

Patients and staff from 12 PCOs in the East Midlands in the development stage, and 15 PCOs across three different regions of England in stage 3.

Interventions

To investigate what responsiveness means, we conducted a literature review and interviews with patients and staff in 12 PCOs. We developed, tested and piloted the use of a questionnaire. We explored approaches for GP practices to understand the diversity of their populations.

Main outcome measures

(1) Definition of primary care responsiveness. (2) Three patient-report questionnaires to provide an assessment of patient experience of GP, pharmacy and walk-in centre responsiveness. (3) Insight into challenges in collecting diversity data in primary care.

Results

The literature covers three overlapping themes of service quality, inequalities and patient involvement. We suggest that responsiveness is achieved through alignment between service delivery and patient needs, involving strategies to improve responsive service delivery, and efforts to manage patient expectations. We identified three components of responsive service delivery: proactive population orientation, reactive population orientation and individual patient orientation. PCOs tend to utilise reactive strategies rather than proactive approaches. Questionnaire development involved efforts to include patients who are ‘seldom heard’. The questionnaire was checked for validity and consistency and is available in three versions (GP, pharmacy, and walk-in centre), and in Easy Read format. We found the questionnaires to be acceptable to patients, and to have content validity. We produced some preliminary evidence of reliability and construct validity. Measuring and improving responsiveness requires PCOs to understand the characteristics of their patient population, but we identified significant barriers and challenges to this.

Conclusions

Responsiveness is a complex concept. It involves alignment between service delivery and the needs of diverse patient groups. Reactive and proactive strategies at individual and population level are required, but PCOs mainly rely on reactive approaches. Being responsive means giving good care equally to all, and some groups may require extra support. What this extra support is will differ in different patient populations, and so knowledge of the practice population is essential. Practices need to be motivated to collect and use diversity data. Future work needed includes further evaluation of the patient-report questionnaires, including Easy Read versions, to provide further evidence of their quality and acceptability; research into how to facilitative the use of patient experience data in primary care; and implementation of strategies to improve responsiveness, and evaluation of effectiveness.

Funding

The National Institute for Health Research Service Delivery and Organisation programme.

Reuse of clinical data

OBJECTIVES

To provide an overview of the benefits of clinical data collected as a by-product of the care process, the potential problems with large aggregations of these data, the policy frameworks that have been formulated, and the major challenges in the coming years.

METHODS

This report summarizes some of the major observations from AMIA and IMIA conferences held on this admittedly broad topic from 2006 through 2013. This report also includes many unsupported opinions of the author.

RESULTS

The benefits of aggregating larger and larger sets of routinely collected clinical data are well documented and of great societal benefit. These large data sets will probably never answer all possible clinical questions for methodological reasons. Non-traditional sources of health data that are patient-sources will pose new data science challenges.

CONCLUSIONS

If we ever hope to have tools that can rapidly provide evidence for daily practice of medicine we need a science of health data perhaps modeled after the science of astronomy.

Risk of pneumonia with inhaled corticosteroid versus long-acting bronchodilator regimens in chronic obstructive pulmonary disease: a new-user cohort study

INTRODUCTION

Observational studies using case-control designs have showed an increased risk of pneumonia associated with inhaled corticosteroid (ICS)-containing medications in patients with chronic obstructive pulmonary disease (COPD). New-user observational cohort designs may minimize biases associated with previous case-control designs.

OBJECTIVE

To estimate the association between ICS and pneumonia among new users of ICS relative to inhaled long-acting bronchodilator (LABD) monotherapy.

METHODS

Pneumonia events in COPD patients ≥45 years old were compared among new users of ICS medications (n = 11,555; ICS, ICS/long-acting β2-agonist [LABA] combination) and inhaled LABD monotherapies (n = 6,492; LABA, long-acting muscarinic antagonists) using Cox proportional hazards models, with propensity scores to adjust for confounding.

SETTING

United Kingdom electronic medical records with linked hospitalization and mortality data (2002-2010). New users were censored at earliest of: pneumonia event, death, changing/discontinuing treatment, or end of follow-up.

OUTCOMES

severe pneumonia (primary) and any pneumonia (secondary).

RESULTS

Following adjustment, new use of ICS-containing medications was associated with an increased risk of pneumonia hospitalization (n = 322 events; HR = 1.55, 95% CI: 1.14, 2.10) and any pneumonia (n = 702 events; HR = 1.49, 95% CI: 1.22, 1.83). Crude incidence rates of any pneumonia were 48.7 and 30.9 per 1000 person years among the ICS-containing and LABD cohorts, respectively. Excess risk of pneumonia with ICS was reduced when requiring ≥1 month or ≥ 6 months of new use. There was an apparent dose-related effect, with greater risk at higher daily doses of ICS. There was evidence of channeling bias, with more severe patients prescribed ICS, for which the analysis may not have completely adjusted.

CONCLUSIONS

The results of this new-user cohort study are consistent with published findings; ICS were associated with a 20-50% increased risk of pneumonia in COPD, which reduced with exposure time. This risk must be weighed against the benefits when prescribing ICS to patients with COPD.

Opportunities to diagnose chronic obstructive pulmonary disease in routine care in the UK: a retrospective study of a clinical cohort

BACKGROUND

Patterns of health-care use and comorbidities present in patients in the period before diagnosis of chronic obstructive pulmonary disease (COPD) are unknown. We investigated these factors to inform future case-finding strategies.

METHODS

We did a retrospective analysis of a clinical cohort in the UK with data from Jan 1, 1990 to Dec 31, 2009 (General Practice Research Database and Optimum Patient Care Research Database). We assessed patients aged 40 years or older who had an electronically coded diagnosis of COPD in their primary care records and had a minimum of 3 years of continuous practice data for COPD (2 years before diagnosis up to a maximum of 20 years, and 1 year after diagnosis) and at least two prescriptions for COPD since diagnosis. We identified missed opportunites to diagnose COPD from routinely collected patient data by reviewing patterns of health-care use and comorbidities present before diagnosis. We assessed patterns of health-care use in terms of lower respiratory consultations (infective and non-infective), lower respiratory consultations with a course of antibiotics or oral steroids, and chest radiography. If these events did not lead to a diagnosis of COPD, they were deemed to be missed opportunities. This study is registered with ClinicalTrials.gov, number NCT01655667.

FINDINGS

We assessed data for 38,859 patients. Opportunities for diagnosis were missed in 32,900 (85%) of 38,859 patients in the 5 years immediately preceding diagnosis of COPD; in 12,856 (58%) of 22,286 in the 6-10 years before diagnosis, in 3943 (42%) of 9351 in the 11-15 years before diagnosis; and in 95 (8%) of 1167 in the 16-20 years before diagnosis. Between 1990 and 2009, we noted decreases in the age at diagnosis (0·05 years of age per year, 95% CI 0·03-0·07) and yearly frequency of lower respiratory prescribing consultations (rate ratio 0·982 opportunities per year, 95% CI 0·979-0·985). Prevalence of all comorbidities present at COPD diagnosis increased except for asthma and bronchiectasis, which decreased between 1990 and 2007, from 281 (33·4%) of 842 patients to 451 of 1465 (30·8%) for asthma, and from 53 of 842 (6·3%) to 53 of 1465 (3·6%) for bronchiectasis. In the 2 years before diagnosis, of 6897 patients who had had a chest radiography, only 2296 (33%) also had spirometry.

INTERPRETATION

Opportunities to diagnose COPD at an earlier stage are being missed, and could be improved by case-finding in patients with lower respiratory tract symptoms and concordant long-term comorbidities.

FUNDING

UK Department of Health, Research in Real Life.

Real-life comparison of beclometasone dipropionate as an extrafine- or larger-particle formulation for asthma

BACKGROUND

Beclometasone dipropionate is an inhaled corticosteroid (ICS) available in both extrafine and larger-particle hydrofluoroalkane formulations. Extrafine beclometasone has greater small airway distribution and inhalation technique tolerance than larger-particle beclometasone; therefore, its use may be associated with improved asthma outcomes at population levels. The study objective was to compare real-life effectiveness of extrafine and larger-particle beclometasone.

METHODS

Retrospective matched cohort study including primary care patients with asthma (ages 12-60 and non-smokers 61-80 years) prescribed extrafine or larger-particle beclometasone by metered-dose inhaler. We studied patients receiving their first ICS (initiation population, n = 11,289) or switched from another ICS without dose change (switch population, n = 19,065). The extrafine and larger-particle beclometasone cohorts were matched in each population for demographic and database measures of asthma control during a baseline year; and endpoints assessed during 1 outcome year were adjusted for residual confounding factors.

RESULTS

The odds of no loss of asthma control (no asthma-related hospital attendance, consultation for lower respiratory tract infection, or oral corticosteroids) were significantly higher in the extrafine beclometasone cohorts of both initiation population (adjusted odds ratio [aOR] 1.12; 95% CI 1.02-1.23) and switch population (aOR 1.10; 95% CI 1.01-1.19). The odds of better adherence to ICS therapy were also significantly higher in both extrafine beclometasone cohorts (initiation population, aOR 1.64; 95% CI 1.52-1.75 and switch population, aOR 1.35; 95% CI 1.27-1.43).

CONCLUSIONS

These findings are consistent with the hypothesis that delivery of beclometasone in extrafine particle size produces real-life asthma treatment benefits. Clinical trials no. NCT01400217.

Optimising use of electronic health records to describe the presentation of rheumatoid arthritis in primary care: a strategy for developing code lists

Background

Research using electronic health records (EHRs) relies heavily on coded clinical data. Due to variation in coding practices, it can be difficult to aggregate the codes for a condition in order to define cases. This paper describes a methodology to develop ‘indicator markers’ found in patients with early rheumatoid arthritis (RA); these are a broader range of codes which may allow a probabilistic case definition to use in cases where no diagnostic code is yet recorded.

Methods

We examined EHRs of 5,843 patients in the General Practice Research Database, aged ≥30y, with a first coded diagnosis of RA between 2005 and 2008. Lists of indicator markers for RA were developed initially by panels of clinicians drawing up code-lists and then modified based on scrutiny of available data. The prevalence of indicator markers, and their temporal relationship to RA codes, was examined in patients from 3y before to 14d after recorded RA diagnosis.

Findings

Indicator markers were common throughout EHRs of RA patients, with 83.5% having 2 or more markers. 34% of patients received a disease-specific prescription before RA was coded; 42% had a referral to rheumatology, and 63% had a test for rheumatoid factor. 65% had at least one joint symptom or sign recorded and in 44% this was at least 6-months before recorded RA diagnosis.

Conclusion

Indicator markers of RA may be valuable for case definition in cases which do not yet have a diagnostic code. The clinical diagnosis of RA is likely to occur some months before it is coded, shown by markers frequently occurring ≥6 months before recorded diagnosis. It is difficult to differentiate delay in diagnosis from delay in recording. Information concealed in free text may be required for the accurate identification of patients and to assess the quality of care in general practice.

Drug-/radiation-induced interstitial lung disease in the United Kingdom general population: incidence, all-cause mortality and characteristics at diagnosis

BACKGROUND AND OBJECTIVE

Radiotherapy and an increasing number of substances are implicated in the pathogenesis of interstitial lung disease (ILD). While the frequency of published data on more common ILD entities such as the idiopathic interstitial pneumonias has increased in recent years, less attention has been given to relatively rarely occurring forms such as drug-/radiation-induced ILD.

METHODS

Data from the UK-based General Practice Research Database (GPRD) was used to estimate the incidence of drug-/radiation-induced ILD over a 12-year period (1997-2008). Crude incidence rates were stratified by gender, age group and calendar period, and rate ratios were adjusted using Poisson regression. All-cause mortality was modelled using Cox regression, and characteristics at diagnosis were compared with a random sample of matched, non-ILD controls using conditional logistic regression.

RESULTS

A total of 128 patients with an incident diagnosis of drug-/radiation-induced ILD were identified, and the overall incidence density during the study period was 4.1 (95% confidence interval 3.4-4.9) per million person-years. Incidence rates increased during the time period 1997-2005 and decreased thereafter. The adjusted all-cause mortality was >4 times higher in cases compared with controls.

CONCLUSIONS

This UK population-based study characterizes patients diagnosed with drug-/radiation-induced ILD and quantifies incidence and all-cause mortality during 1997-2008. No statistically significant time trend in incidence was found, despite having observed numeric increases in incidence rates during the study window. Future research using the GPRD and other data sources is required to better understand the disposition of patients diagnosed with drug-/radiation-induced ILD and to investigate potential trends incidence and mortality over time.

Methods and dimensions of electronic health record data quality assessment: enabling reuse for clinical research

OBJECTIVE

To review the methods and dimensions of data quality assessment in the context of electronic health record (EHR) data reuse for research.

MATERIALS AND METHODS

A review of the clinical research literature discussing data quality assessment methodology for EHR data was performed. Using an iterative process, the aspects of data quality being measured were abstracted and categorized, as well as the methods of assessment used.

RESULTS

Five dimensions of data quality were identified, which are completeness, correctness, concordance, plausibility, and currency, and seven broad categories of data quality assessment methods: comparison with gold standards, data element agreement, data source agreement, distribution comparison, validity checks, log review, and element presence.

DISCUSSION

Examination of the methods by which clinical researchers have investigated the quality and suitability of EHR data for research shows that there are fundamental features of data quality, which may be difficult to measure, as well as proxy dimensions. Researchers interested in the reuse of EHR data for clinical research are recommended to consider the adoption of a consistent taxonomy of EHR data quality, to remain aware of the task-dependence of data quality, to integrate work on data quality assessment from other fields, and to adopt systematic, empirically driven, statistically based methods of data quality assessment.

CONCLUSION

There is currently little consistency or potential generalizability in the methods used to assess EHR data quality. If the reuse of EHR data for clinical research is to become accepted, researchers should adopt validated, systematic methods of EHR data quality assessment.

Epidemiology of clinical body mass index recording in an obese population in primary care: a cohort study

BACKGROUND

Protecting and promoting the health of obese people is an important public health concern. This study evaluated the recording of body mass index and medical diagnostic codes for obesity in obese patients in UK primary care.

METHODS

A cohort study was implemented in the UK General Practice Research Database. Subjects were aged 18-100 years and were diagnosed with obesity between 1997 and 2007. The frequency of obesity monitoring was evaluated.

RESULTS

There were 67 000 obese patients at 127 family practices. The proportion of obese patients with no annual body mass index (BMI) record reached 65% of men and 63% of women in 2000, declining to 55 and 48% in 2009. Medical diagnostic codes for obesity were infrequently recorded. The mean BMI of obese patients increased to 35.5 kg/m(2) [95% confidence interval (CI): 35.4-35.7] in men and 37.0 kg/m(2) (95% CI: 36.9-37.1) in women by 2009. In 2009, 37% of obese men with BMI records, and 39% of women, showed a BMI increase of ≥1 kg/m(2) since the previous reading.

CONCLUSIONS

Obese patients do not have BMI values recorded regularly. The mean BMI of obese patients, and the proportion gaining weight over time, is increasing. Improved strategies for monitoring and managing obesity are required.

Incidence of the pneumoconioses in the United Kingdom general population between 1997 and 2008

BACKGROUND

The incidence of the pneumoconioses in the UK is primarily estimated using occupational-based registries and disability pension schemes. These sources indicate a downward trend in the incidence of the pneumoconioses from 1995 onwards. There are no previously published general population-based observational studies quantifying the incidence of the pneumoconioses in the UK.

OBJECTIVES

The aim of this study was to investigate the incidence of the pneumoconioses in the UK general population between 1997 and 2008 using data from the General Practice Research Database (GPRD).

METHODS

Data from the UK-based GPRD were used to estimate the incidence of pneumoconioses over a 12-year period (1997-2008). Crude incidence rates for asbestosis and non-asbestos-related pneumoconioses were stratified by gender, age group and calendar period, and rate ratios were adjusted using Poisson regression.

RESULTS

The majority of cases was diagnosed with asbestosis, and the overall, crude incidence density for this pneumoconiosis during the 12-year study period was 2.7 (95% confidence interval 2.5-2.9) per 100,000 person-years. The incidence increased progressively during the period 1997-2005 and then decreased slightly during the period 2006-2008, even after controlling for the strong effect of an ageing UK population. The non-asbestos-related pneumoconioses, in contrast to asbestosis, showed a progressive reduction in incidence from 2003 onwards.

CONCLUSIONS

This study demonstrates that the pneumoconioses remain an important public health issue and, furthermore, documents an overall increase in asbestosis incidence in the UK between 1997 and 2008.

The natural history of community-acquired pneumonia in COPD patients: a population database analysis

BACKGROUND

Patients with Chronic Obstructive Pulmonary Disease (COPD) are at higher risk of developing Community-Acquired Pneumonia (CAP) than patients in the general population. However, no studies have been performed in general practice assessing longitudinal incidence rates for CAP in COPD patients or risk factors for pneumonia onset.

METHODS

A cohort of COPD patients aged ≥ 45 years, was identified in the General Research Practice Database (GPRD) between 1996 and 2005, and annual and 10-year incidence rates of CAP evaluated. A nested case-control analysis was performed, comparing descriptors in COPD patients with and without CAP using conditional logistic regression generating odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

The COPD cohort consisted of 40,414 adults. During the observation period, 3149 patients (8%) experienced CAP, producing an incidence rate of 22.4 (95% CI 21.7-23.2) per 1000 person years. 92% of patients with pneumonia diagnosis had suffered only one episode. Multivariate modelling of pneumonia descriptors in COPD indicate that age over 65 years was significantly associated with increased risk of CAP. Other independent risk factors associated with CAP were co-morbidities including congestive heart failure (OR 1.4, 95% CI 1.2-1.6), and dementia (OR 2.6, 95%CI 1.9-3.). Prior severe COPD exacerbations requiring hospitalization (OR 2.7, 95% CI 2.3-3.2) and severe COPD requiring home oxygen or nebulised therapy (OR 1.4, 95% CI 1.1-1.6) were also significantly associated with risk of CAP.

CONCLUSION

COPD patients presenting in general practice with specific co-morbidities, severe COPD, and age >65 years are at increased risk of CAP.

Effectiveness of same versus mixed asthma inhaler devices: a retrospective observational study in primary care

PURPOSE

Correct use of inhaler devices is fundamental to effective asthma management but represents an important challenge for patients. The correct inhalation manoeuvre differs markedly for different inhaler types. The objective of this study was to compare outcomes for patients prescribed the same inhaler device versus mixed device types for asthma controller and reliever therapy.

METHODS

This retrospective observational study identified patients with asthma (ages 4-80 years) in a large primary care database who were prescribed an inhaled corticosteroid (ICS) for the first time. We compared outcomes for patients prescribed the same breath-actuated inhaler (BAI) for ICS controller and salbutamol reliever versus mixed devices (BAI for controller and pressurised metered-dose inhaler [pMDI] for reliever). The 2-year study included 1 baseline year before the ICS prescription (to identify and correct for confounding factors) and 1 outcome year. Endpoints were asthma control (defined as no hospital attendance for asthma, oral corticosteroids, or antibiotics for lower respiratory tract infection) and severe exacerbations (hospitalisation or oral corticosteroids for asthma).

RESULTS

Patients prescribed the same device (n=3,428) were significantly more likely to achieve asthma control (adjusted odds ratio, 1.15; 95% confidence interval [CI], 1.02-1.28) and recorded significantly lower severe exacerbation rates (adjusted rate ratio, 0.79; 95% CI, 0.68-0.93) than those prescribed mixed devices (n=5,452).

CONCLUSIONS

These findings suggest that, when possible, the same device should be prescribed for both ICS and reliever therapy when patients are initiating ICS.

Long-term health outcomes in a British cohort of breast, colorectal and prostate cancer survivors: a database study

Background:

The community-based incidence of cancer treatment-related long-term consequences is uncertain. We sought to establish the burden of health outcomes that have been associated with treatment among British long-term cancer survivors.

Methods:

We identified 26 213 adults from the General Practice Research Database who have survived 5 years or more following breast, colorectal or prostate cancer. Four age-, sex- and general practice-matched non-cancer controls were selected for each survivor. We considered the incidence of treatment-associated health outcomes using Cox proportional hazards models.

Results:

Breast cancer survivors had an elevated incidence of heart failure (hazards ratio (HR) 1.95, 95% confidence interval (CI) 1.27–3.01), coronary artery disease (HR 1.27, 95% CI 1.11–1.44), hypothyroidism (HR 1.26, 95% CI 1.02–1.56) and osteoporosis (HR 1.26, 95% CI 1.13–1.40). Among colorectal cancer survivors, there was increased incidence of dementia (HR 1.68, 95% CI 1.20–2.35), diabetes (HR 1.39, 95% CI 1.12–1.72) and osteoporosis (HR 1.41, 95% CI 1.15–1.73). Prostate cancer survivors had the highest risk of osteoporosis (HR 2.49, 95% CI 1.93–3.22).

Conclusions:

The study confirms the occurrence of increased incidence of chronic illnesses in long-term cancer survivors attributable to underlying lifestyle and/or cancer treatments. Although the absolute risk of the majority of late effects in the cancer survivors cohort is low, identifying prior risk of osteoporosis by bone mineral density scanning for prostate survivors should be considered. There is an urgent need to improve primary care recording of cancer treatment.

Long-term use of fluticasone propionate/salmeterol fixed-dose combination and incidence of cataracts and glaucoma among chronic obstructive pulmonary disease patients in the UK General Practice Research Database

Objectives

Some large population-based studies have reported a dose-related increased risk of cataracts and glaucoma associated with use of inhaled corticosteroids (ICS) in patients with asthma or chronic obstructive pulmonary disease (COPD). We evaluated the association between use of ICS-containing products, specifically fluticasone propionate/salmeterol fixed-dose combination (FSC), and incidence of cataracts and glaucoma among patients with COPD in a large electronic medical record database in the United Kingdom.

Methods

We identified a cohort of patients aged 45 years and over with COPD in the General Practice Research Database (GPRD) between 2003 and 2006. Cases of incident cataracts or glaucoma were defined based on diagnosis and procedure codes and matched to controls from the risk set to estimate odds ratios (OR) and 95% confidence intervals (CI). The association with FSC or ICS exposure was modeled using conditional logistic regression. Medication exposure was assessed with respect to recency, duration, and number of prescriptions prior to the index date. Average daily dose was defined as none, low (1–250 mcg), medium (251–500 mcg), high (501–1000 mcg), or very high (1001+ mcg) using fluticasone propionate (FP) equivalents.

Results

We identified 2941 incident cataract cases and 327 incident glaucoma cases in the COPD cohort (n = 53,191). FSC or ICS prescriptions were not associated with risk of incident cataracts or glaucoma for any exposure category, after adjusting for confounders. We observed a lack of a dose response in all analyses, where low dose was the reference group. The odds of cataracts associated with FSC dose were medium OR: 1.1 (95% CI: 0.9–1.4); high OR: 1.2 (95% CI: 0.9–1.5); and very high OR: 1.2 (95% CI: 0.9–1.7). The odds of glaucoma associated with FSC dose: medium OR: 1.0 (95% CI: 0.5–2.1); high OR: 1.0 (95% CI: 0.5–2.0); and very high OR: 1.0 (95% CI: 0.4–2.8).

Conclusions

FSC or other ICS exposure was not associated with an increased odds of cataracts or glaucoma, nor was a dose–response relationship observed in this population-based nested case-control study of COPD patients in the United Kingdom.

The relationship between asthma and depression in primary care patients: a historical cohort and nested case control study

BACKGROUND AND OBJECTIVES

Asthma and depression are common health problems in primary care. Evidence of a relationship between asthma and depression is conflicting.

OBJECTIVES

to determine 1. The incidence rate and incidence rate ratio of depression in primary care patients with asthma compared to those without asthma, and 2. The standardized mortality ratio of depressed compared to non-depressed patients with asthma.

METHODS

A historical cohort and nested case control study using data derived from the United Kingdom General Practice Research Database.

PARTICIPANTS

11,275 incident cases of asthma recorded between 1/1/95 and 31/12/96 age, sex and practice matched with non-cases from the database (ratio 1:1) and followed up through the database for 10 years. 1,660 cases were matched by date of asthma diagnosis with 1,660 controls.

MAIN OUTCOME MEASURES

number of cases diagnosed with depression, the number of deaths over the study period.

RESULTS

The rate of depression in patients with asthma was 22.4/1,000 person years and without asthma 13.8 /1,000 person years. The incident rate ratio (adjusted for age, sex, practice, diabetes, cardiovascular disease, cerebrovascular disease, smoking) was 1.59 (95% CI 1.48-1.71). The increased rate of depression was not associated with asthma severity or oral corticosteroid use. It was associated with the number of consultations (odds ratio per visit 1.09; 95% CI 1.07-1.11). The age and sex adjusted standardized mortality ratio for depressed patients with asthma was 1.87 (95% CI: 1.54-2.27).

CONCLUSIONS

Asthma is associated with depression. This was not related to asthma severity or oral corticosteroid use but was related to service use. This suggests that a diagnosis of depression is related to health seeking behavior in patients with asthma. There is an increased mortality rate in depressed patients with asthma. The cause of this needs further exploration. Consideration should be given to case-finding for depression in this population.

Prevalence of long-term oral glucocorticoid prescriptions in the UK over the past 20 years

OBJECTIVE

To assess trends in long-term (i.e. ≥3 months) oral glucocorticoid (GC) prescriptions over the past 20 years.

METHODS

Data of UK adult patients registered between January 1989 and December 2008 with general practices contributing to The Health Improvement Network (THIN) database were obtained. The annual prevalence of long-term oral GC prescriptions was assessed in the whole population and specifically in people with RA, PMR/GCA, asthma, chronic obstructive pulmonary disease (COPD), Crohn's disease and ulcerative colitis (UC). Trends over the 20-year period were estimated using sex- and age-adjusted Poisson regression models.

RESULTS

During the 26 035 154 person-years of follow-up, an average of 0.75% (95% CI 0.74, 0.75) of the study population was prescribed long-term oral GC therapy at any time point. This rose from 0.59% (0.52, 0.67) in 1989 to 0.79% (0.78, 0.80) in 2008. Long-term prescriptions significantly increased in patients with RA [from 10.3% (8.7, 11.9) to 13.6% (12.9, 14.2)] and PMR/GCA [from 57.6% (53.3, 62.0) to 66.5% (65.2, 67.7)], decreased in patients with asthma, COPD and Crohn's disease and remained stable in patients with UC. However, when only incident cases were considered, we found a decreased use of GCs in patients with RA and UC [odds ratio 0.97 (95% CI 0.96, 0.97) and 0.94 (95% CI 0.93, 0.96) per increasing year, respectively].

CONCLUSION

Over the past 20 years, long-term oral GC prescriptions have increased by 34%. Patients newly diagnosed with RA, Crohn's disease or UC are, however, less likely to receive long-term GC prescriptions than patients with a long past medical history of the disease, suggesting changes in physicians' practice.

[Incidence rate of community acquired pneumonia in a population cohort registered in BIFAP]

OBJECTIVE

To estimate the incidence rate (IR) of community acquired pneumonia (CAP) using the information in the Primary Healthcare database in Spain.

DESIGN

Retrospective study (2003-2007) using the information registered in the Database for Pharmaco-Epidemiological Research in Primary Care (BIFAP).

STUDY POPULATION

Subjects aged 20 to 79 years old, were followed up until the occurrence of a pneumonia episode, death, age of 80, or the end of the study, whichever came first. CASE SELECTION: A computerised search was performed to detect suggestive cases of pneumonia using ICPC codes (International Classification of Primary Care) and free text. The computerised histories were manually reviewed in order to identify those cases fulfilling the CAP's determined definition. ANALYSE: IR of pneumonia was computed by age, sex and season. The percentage of hospitalisation was estimated. These results were compared with the IR from the United Kingdom using THIN database (The Health Improvement Network).

RESULTS

IR of CAP was 2.69 per 1000 persons-year (IR women=2.29; IR men=3.16) with BIFAP database, and 32 % of the CAP cases were hospitalised. In United Kingdom, IR was 1.07 per 1000 persons-year (IR women=0.93; IR men=1.22) and 17% of CAP were hospitalised.

CONCLUSION

The BIFAP computerised Primary Care database is useful to estimate the incidence rate of CAP in Spain, as well as to compare the results with those obtained using other European computerised Primary Care databases.

Validation of ischemic cerebrovascular diagnoses in the health improvement network (THIN)

PURPOSE

To evaluate the validity of recorded diagnoses of ischemic cerebrovascular events requiring hospitalization within The Health Improvement Network (THIN) UK primary care database.

METHODS

We identified 15 397 individuals aged 40-84 years with a first recorded ischemic event in 2000-2004. Of these, 4239 had a code suggestive of a hospitalization within 2 weeks of the event. A three-step strategy was used to validate the records of these patients: manual review of computerized medical records excluding free-text comments; manual review including free-text comments (which include information gained from specialists, hospital discharge letters and results of diagnostic tests) of a random sample of possible cases (n = 300) and non-cases (n = 100); and review of full medical records of this random sample and a questionnaire completed by their primary care physician. The positive predictive value (PPV) of each step was calculated. The confirmation rate was used to estimate incidence in the general population.

RESULTS

After step 1, 3447 individuals were classified as possible cases and 792 were excluded as non-cases. After step 2, 82% of possible cases were still classified as such. Step 3 showed that inclusion of free-text comments increased the PPV of a diagnosis from 76 to 86%. The weighted incidence of hospitalized ischemic cerebrovascular events was 1.73 per 1000 person-years (95% CI:1.68-1.77).

CONCLUSIONS

THIN demonstrates a high validity for the study of ischemic cerebrovascular events when reviewing computer records with additional free-text comments. Accuracy of hospitalization status was not as well recorded.

Cost-effectiveness analysis of corticosteroid inhaler devices in primary care asthma management: A real world observational study

PURPOSE

To evaluate and compare real world cost-effectiveness of inhaled corticosteroids (ICS) administered by metered dose inhaler (MDI), breath-actuated MDI (BAI), or dry powder inhaler (DPI) in asthma.

PATIENTS AND METHODS

This retrospective database study analyzed the direct health care costs and proportion of patients (aged 5-60 years) achieving asthma control over 1 year in two population groups: those starting ICS (initiation population) and those receiving a first increase in ICS dose (step-up population). Asthma control was defined as no unplanned asthma visits, oral corticosteroids, or antibiotics for lower respiratory infection; outcomes were adjusted for confounding variables. Cost-effectiveness of BAI and DPI were compared with MDI.

RESULTS

For the initiation population (n = 56,347), average annual health care costs per person (adjusted results), as compared with MDIs, were £9 higher (95% CI: -1.65 to 19.71) for BAIs and £32 higher (95% CI: 19.51 to 43.66) for DPIs. The probability of BAIs being the dominant strategy (more effective and less costly than MDIs) was 5% and of BAIs being more effective and more costly than MDIs was 94%. DPIs were consistently more effective and more costly than MDIs, with an incremental cost-effectiveness ratio of £1711 (95% CI: 760 to 3,576) per additional controlled patient per year. For the step-up population (n = 9169), mean total health care costs per person, (adjusted) as compared with MDIs, were £1 higher (95% CI: -27.28 to 31.55) for BAIs and £73 higher (95% CI: 44.48 to 103.29) for DPIs. The probability of BAIs being dominant was 48% and of BAIs being more effective but more costly than MDIs was 52%; the probability of DPIs being more effective but more costly than MDIs was 96%.

CONCLUSION

The real world effectiveness of ICS inhalers may vary, and inhaler device selection for patients with asthma should take into consideration not only initial device cost but also the subsequent health care resource costs.

Validity of diagnostic coding within the General Practice Research Database: a systematic review

BACKGROUND

The UK-based General Practice Research Database (GPRD) is a valuable source of longitudinal primary care records and is increasingly used for epidemiological research.

AIM

To conduct a systematic review of the literature on accuracy and completeness of diagnostic coding in the GPRD.

DESIGN OF STUDY

Systematic review.

METHOD

Six electronic databases were searched using search terms relating to the GPRD, in association with terms synonymous with validity, accuracy, concordance, and recording. A positive predictive value was calculated for each diagnosis that considered a comparison with a gold standard. Studies were also considered that compared the GPRD with other databases and national statistics.

RESULTS

A total of 49 papers are included in this review. Forty papers conducted validation of a clinical diagnosis in the GPRD. When assessed against a gold standard (validation using GP questionnaire, primary care medical records, or hospital correspondence), most of the diagnoses were accurately recorded in the patient electronic record. Acute conditions were not as well recorded, with positive predictive values lower than 50%. Twelve papers compared prevalence or consultation rates in the GPRD against other primary care databases or national statistics. Generally, there was good agreement between disease prevalence and consultation rates between the GPRD and other datasets; however, rates of diabetes and musculoskeletal conditions were underestimated in the GPRD.

CONCLUSION

Most of the diagnoses coded in the GPRD are well recorded. Researchers using the GPRD may want to consider how well the disease of interest is recorded before planning research, and consider how to optimise the identification of clinical events.

Prescribing patterns of asthma controller therapy for children in UK primary care: a cross-sectional observational study

Background

Asthma management guidelines recommend a stepwise approach to instituting and adjusting anti-inflammatory controller therapy for children with asthma. The objective of this retrospective observational study was to describe prescribing patterns of asthma controller therapies for children in a primary care setting.

Methods

Data from the UK General Practice Research Database were examined for children with recorded asthma or recurrent wheezing who, from September 2006 through February 2007, were ≤ 14 years old at the time of a first asthma controller prescription after ≥ 6 months without a controller prescription. We evaluated demographic characteristics, asthma duration, comorbidities, asthma-related health care resource use, and prescribed daily dose of controller medication. In addition, physicians for 635 randomly selected patients completed a survey retrospectively classifying asthma severity at the prescription date and describing therapy and health care utilization for 6 prior months.

Results

We identified 10,004 children, 5942 (59.4%) of them boys, of mean (SD) age of 8.0 (3.8) years. Asthma controller prescriptions were for inhaled corticosteroid (ICS) monotherapy for 9059 (90.6%) children; ICS plus long-acting β2-agonist (LABA) for 698 (7.0%); leukotriene antagonist monotherapy for 91 (0.9%); ICS plus leukotriene antagonist for 55 (0.6%); and other therapy for 101 (1.0%), including 45 (0.45%) children who were prescribed LABA as monotherapy. High doses of ICS (> 400 μg) were prescribed for 44/2140 (2.1%) children < 5 years old and for 420/7452 (5.6%) children ≥ 5 years. Physicians reported asthma severity as intermittent for 346/635 (55%) patients and as mild, moderate, and severe persistent for 159 (25%), 71 (11%), and 11 (2%), respectively (severity data missing for 48 [8%]). The baseline characteristics and controller therapy prescriptions of the survey cohort were similar to those of the full cohort.

Conclusions

Physician classifications of asthma severity did not always correspond to guideline recommendations, as leukotriene receptor antagonists were rarely used and high-dose ICS or add-on LABA was prescribed even in intermittent and mild disease. In UK primary care, monotherapy with ICS is the most common controller therapy at all levels of asthma severity.

Pulmonary sarcoidosis: the 'Great Pretender'

Sarcoidosis has a wide spectrum of appearances within the thorax. This review will discuss and illustrate the range of pulmonary manifestations on high-resolution computed tomography and chest radiography, concentrating on atypical features and examples of sarcoidosis mimicking other lung diseases. All included cases have been histologically confirmed. Such variable imaging appearances should alert the radiologist to consider sarcoidosis as a differential diagnosis in the context of interstitial lung disease.

Declining 1-year case-fatality of stroke and increasing coverage of vascular risk management: population-based cohort study

BACKGROUND

The authors estimated trends in 1-year case-fatality of stroke in relation to changes in vascular risk management from 1997 to 2005.

METHODS

A cohort study was implemented using data for 407 family practices in the UK General Practice Research Database, including subjects with first acute strokes between 1997 and 2005. One-year case-fatality was estimated by year and sex. Rate ratios were estimated using Poisson regression.

RESULTS

There were 19 143 women and 16 552 men who had first acute strokes between 1997 and 2005. In women, the 1-year case-fatality declined from 41.2% in 1997 to 29.2% in 2005. In men, the decline was from 29.2% in 1997 to 22.2% in 2005. The proportion of general practices that prescribed antihypertensive drugs to two-thirds or more of new patients with stroke increased from 6% in 1997 to 48% in 2005, for statins from 1% to 39% and for antiplatelet drugs from 11% to 39%. The rate ratio for 1-year mortality in 2005, compared with 1997-1998, adjusted for age group, sex, prevalent coronary heart disease, prevalent hypertension and deprivation quintile was 0.79 (0.74 to 0.86, p<0.001). After adjustment for antihypertensive, statin and antiplatelet prescribing, the rate ratio was 1.29 (1.17 to 1.42).

CONCLUSIONS

Reducing 1-year case-fatality after acute stroke may be partly explained by increased prescribing of antihypertensive, statin and antiplatelet drugs to patients with recent strokes. However, these analyses did not include measures of possible changes over time in stroke severity or acute stroke management.

Chronic obstructive pulmonary disease in UK primary care: incidence and risk factors

We evaluated the association of chronic obstructive pulmonary disease (COPD) with modifiable risk factors such as smoking and prescription medications, and investigated possible risk factors unique to patients who had never smoked. The UK General Practice Research Database was used to identify a cohort of patients with a first diagnosis of COPD (n = 1927) along with age- and sex-matched controls without COPD (n = 16 546). The incidence of COPD diagnoses and the risks associated with medication use, co-morbidities, and demographic factors, were estimated. The incidence of COPD was 2.6 per 1000 person-years (95% confidence interval [CI]: 2.5-2.7) among 40-89 year-olds. The risk significantly increased in current and former smokers (OR: 6.15 [95% CI: 5.41-7.00] and 3.45 [95% CI: 2.96-4.02]), respectively. The risk was significantly lower in former smokers than current smokers (OR: 0.61; 95% CI: 0.52-0.71). Current statin use was significantly associated with a reduced risk (OR: 0.45; 95% CI: 0.25-0.80). In never smokers, risk factors included advanced age and obesity. The risk in never smokers was more strongly related to paracetamol use (OR: 1.82; 95% CI: 1.33-2.49) than in current and former smokers (OR: 1.48; 95% CI: 1.18-1.86). In summary, COPD is associated with a range of cardiovascular and respiratory conditions and the risk is influenced by current and past medications. While the risk factors are similar in smokers and never smokers, some were unique to never smokers. Moreover, subjects who stopped smoking had a substantially lower COPD risk than those who continued smoking.

Selective decrease in consultations and antibiotic prescribing for acute respiratory tract infections in UK primary care up to 2006

BACKGROUND

The aim of this study was to estimate trends in primary care consultations and antibiotic prescribing for acute respiratory tract infections (RTIs) in the UK from 1997 to 2006.

METHODS

Data were analysed for 100,000 subjects registered with 78 family practices in the UK General Practice Research Database; the numbers of consultations for RTI and associated antibiotic prescriptions were enumerated.

RESULTS

The consultation rate for RTI declined in females from 442.2 per 1000 registered patients in 1997 to 330.9 in 2006, and in males from 318.5 to 249.0. The rate of consultations for colds, rhinitis and upper respiratory tract infection (URTI) declined by 4.2 (95% CI 2.3-6.1) per 1000 per year in females and by 3.6 (2.3-4.8) in males. The rate of antibiotic prescribing for RTI was higher in females and declined by 8.5 (2.0-15.1) per 1000 in females and 6.7 (2.7-10.8) in males. For colds, rhinitis and URTI, the proportion of consultations with antibiotics was prescribed declined by 1.7% per year in females and 1.8% in males.

CONCLUSIONS

Decreasing frequency of consultation and antibiotic prescription for colds, rhinitis and 'URTI' continues to drive a reduction in the rate of antibiotic utilization for RTIs.

Previous maternal oral contraception and the risk among subsequent offspring of asthma diagnosis in early childhood

Previous maternal use of the oral contraceptive pill (OCP) has been linked with asthma in subsequent offspring and has been implicated in the increased prevalence of childhood asthma in recent decades. We conducted a matched case-control study to test the hypothesis that maternal OCP used close to conception is associated with asthma in the offspring, particularly in children with coexistent eczema. We examined maternal OCP exposure in relation to asthma in the offspring (n = 6730) compared with offspring with no asthma (n = 6730) further stratifying by eczema, age group, treatment category and gender of the offspring. Maternal use of OCP was classified as: no OCP use in the 2 years prior to conception; past OCP use within 2 years but >6 months before conception; and recent OCP use within 6 months of conception. The adjusted odds ratio (OR) for asthma in the offspring was 1.16 [95% confidence interval 1.06, 1.27] among mothers who were recent users of the OCP when compared with mothers who had not used the OCP. Past OCP use was not associated with asthma in the offspring. In the stratified analyses, we observed weak but statistically significant associations between recent maternal OCP use and asthma in the offspring among children: without a history of eczema (adjusted OR 1.22 [1.09, 1.36]), those aged < or = 3 years (adjusted OR 1.24 [1.12, 1.37]), those not on treatment for their asthma (adjusted OR 1.33 [1.12, 1.58]) and among females (adjusted OR 1.34 [1.13, 1.51]). We did not find convincing evidence for a causal relationship between maternal OCP used close to conception and asthma in the offspring. The small statistically significant associations were not among children with characteristic features of asthma such as those with eczema and may be due to bias, uncontrolled confounding or chance.