nan Hurst

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. Bronchiectasis is increasing in incidence and prevalence in the UK, and is associated with an increased mortality http://ow.ly/Sh3Y9

Predictive accuracy of patient-reported exacerbation frequency in COPD

Chronic obstructive pulmonary disease (COPD) exacerbation frequency is important for clinical risk assessment and trial recruitment. In order to accurately establish exacerbation frequency, patients need to be followed for 1 yr, although this is not always practical. 1) Patient recall of exacerbation number during the year prior to recruitment to the London COPD cohort was compared with the number of exacerbations recorded on diary cards during the subsequent year; and 2) patient recall of their exacerbation number after 1 yr of follow-up was compared with documented exacerbations over the same year. A total of 267 patients (forced expiratory volume in 1 s 1.14 L) recorded worsening of respiratory symptoms on daily diary cards for 1 yr. Exacerbations were defined according to previously validated criteria. There was no difference between the exacerbation number recalled by patients prior to recruitment and the number detected during the first year (median 2.0 (interquartile range 1.0–4.0) and 2.0 (1.0–4.0); expected agreement 76.4%; agreement 84.6%; &kgr; = 0.3469). There was no difference between the number of exacerbations remembered by patients and the number recorded on diary cards over the same 1-yr period (2.0 (1.0–4.0) for both groups; expected agreement 74.9%; actual agreement 93.3%; &kgr; = 0.6146). Patients remember the number of exacerbations they have in a year. Accuracy is increased when comparing the same 1-yr period. Patient recall is sufficiently robust for stratification into frequent and infrequent exacerbator groups for subsequent years.

Validation of chronic obstructive pulmonary disease recording in the Clinical Practice Research Datalink (CPRD-GOLD)

Objectives The optimal method of identifying people with chronic obstructive pulmonary disease (COPD) from electronic primary care records is not known. We assessed the accuracy of different approaches using the Clinical Practice Research Datalink, a UK electronic health record database. Setting 951 participants registered with a CPRD practice in the UK between 1 January 2004 and 31 December 2012. Individuals were selected for ≥1 of 8 algorithms to identify people with COPD. General practitioners were sent a brief questionnaire and additional evidence to support a COPD diagnosis was requested. All information received was reviewed independently by two respiratory physicians whose opinion was taken as the gold standard. Primary outcome measure The primary measure of accuracy was the positive predictive value (PPV), the proportion of people identified by each algorithm for whom COPD was confirmed. Results 951 questionnaires were sent and 738 (78%) returned. After quality control, 696 (73.2%) patients were included in the final analysis. All four algorithms including a specific COPD diagnostic code performed well. Using a diagnostic code alone, the PPV was 86.5% (77.5–92.3%) while requiring a diagnosis plus spirometry plus specific medication; the PPV was slightly higher at 89.4% (80.7–94.5%) but reduced case numbers by 10%. Algorithms without specific diagnostic codes had low PPVs (range 12.2–44.4%). Conclusions Patients with COPD can be accurately identified from UK primary care records using specific diagnostic codes. Requiring spirometry or COPD medications only marginally improved accuracy. The high accuracy applies since the introduction of an incentivised disease register for COPD as part of Quality and Outcomes Framework in 2004.

Detrended fluctuation analysis of peak expiratory flow and exacerbation frequency in COPD

We investigated whether exacerbation frequency in chronic obstructive pulmonary disease (COPD) was related to an exponent &agr; which quantifies self-similarity in daily peak expiratory flow (PEF) and is calculated using detrended fluctuation analysis (DFA). We examined data from COPD patients who recorded an increase in respiratory symptoms and post-bronchodilator PEF on daily diary cards. We also investigated PEF data from a double-blind, placebo-controlled trial of the anti-cholinergic agent, tiotropium. In the observational study there were 308 patients with COPD (195 males; mean±sd age 68.3±8.4 yrs, forced expiratory volume in 1 s (FEV1) 1.12±0.46 L, FEV1 % predicted 44.5±16.4%). The mean±sd &agr; over the first year was 0.944±0.19 and it was positively related to the frequency of exacerbations per year (p=0.009). In the clinical trial, &agr; was lower in COPD patients randomised to tiotropium, mean±sd 0.87±0.21 (n=48) than on placebo, mean±sd 0.95±0.19 (n=52; p=0.035). Power analysis showed that fewer patients would be required for clinical studies with &agr; as the outcome measure than exacerbation frequency. DFA shows that daily PEF in COPD has long-term correlations which are related to exacerbation frequency. Monitoring of PEF and use of &agr; may result in smaller COPD patient sample sizes in trials.

How to assess the severity of bronchiectasis.

Wait long enough for a bus and two arrive at once. As with buses, so with bronchiectasis scoring systems. In this issue of the European Respiratory Journal Martinez-Garcia et al. [1] report the development of a “FACED” bronchiectasis prognostic score. This follows the recent publication by Chalmers et al. [2] of the “Bronchiectasis Severity Index” (BSI). Bronchiectasis is a neglected disease and research in the area is to be welcomed, especially when it enables us to manage our patients more appropriately. But, like any good research, these studies raise as many questions as answers: most importantly, what do we even mean when we talk about bronchiectasis “severity”? Current definitions of bronchiectasis have two components. The landmark British Thoracic Society guidance emphasises the concept of “clinically significant” bronchiectasis [3]; the presence of “symptoms of persistent or recurrent bronchial sepsis”, in addition to the permanent airway structural damage that represents the accepted pathology definition. Tools to grade the degree and extent, or “severity” of the radiological component already exist; e.g. scoring systems described by Reiff et al. [4] and Bhalla et al. [5]. These are not without problems. Importantly, patients can have similar severity scores arising from structurally more abnormal but localised disease, or …

Dose response of continuous positive airway pressure on nasal symptoms, obstruction and inflammation in vivo and in vitro

Obstructive sleep apnoea is a common condition associated with cardiovascular risk. Continuous positive airway pressure (CPAP) is an effective treatment but is associated with nasal side-effects, which hinder compliance and may result from inflammation. We investigated whether CPAP was pro-inflammatory to human subjects in vivo, and to cultured bronchial epithelial cells in vitro. In vivo, we further investigated whether induction of nasal inflammation was associated with the development of systemic inflammation, nasal symptoms and changes in nasal mucociliary clearance. In vitro, CPAP resulted in cytokine release from cultured BEAS-2B cells in a time- and dose (pressure)-dependent manner. In vivo, CPAP resulted in dose-dependent upregulation of nasal inflammatory markers associated with the development of nasal symptoms, and reduced mucociliary clearance. CPAP also upregulated selected markers of systemic inflammation. CPAP results in dose-dependent release of inflammatory cytokines from human epithelial cells in vitro and in vivo. In vivo responses were associated with systemic inflammation, reductions in nasal mucociliary function and the development of nasal symptoms. This emphasises the need for novel strategies to reduce nasal inflammation and therefore aid compliance.

Recording of hospitalizations for acute exacerbations of COPD in UK electronic health care records.

Background Accurate identification of hospitalizations for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) within electronic health care records is important for research, public health, and to inform health care utilization and service provision. We aimed to develop a strategy to identify hospitalizations for AECOPD in secondary care data and to investigate the validity of strategies to identify hospitalizations for AECOPD in primary care data. Methods We identified patients with chronic obstructive pulmonary disease (COPD) in the Clinical Practice Research Datalink (CPRD) with linked Hospital Episodes Statistics (HES) data. We used discharge summaries for recent hospitalizations for AECOPD to develop a strategy to identify the recording of hospitalizations for AECOPD in HES. We then used the HES strategy as a reference standard to investigate the positive predictive value (PPV) and sensitivity of strategies for identifying AECOPD using general practice CPRD data. We tested two strategies: 1) codes for hospitalization for AECOPD and 2) a code for AECOPD other than hospitalization on the same day as a code for hospitalization due to unspecified reason. Results In total, 27,182 patients with COPD were included. Our strategy to identify hospitalizations for AECOPD in HES had a sensitivity of 87.5%. When compared with HES, using a code suggesting hospitalization for AECOPD in CPRD resulted in a PPV of 50.2% (95% confidence interval [CI] 48.5%–51.8%) and a sensitivity of 4.1% (95% CI 3.9%–4.3%). Using a code for AECOPD and a code for hospitalization due to unspecified reason resulted in a PPV of 43.3% (95% CI 42.3%–44.2%) and a sensitivity of 5.4% (95% CI 5.1%–5.7%). Conclusion Hospitalization for AECOPD can be identified with high sensitivity in the HES database. The PPV and sensitivity of strategies to identify hospitalizations for AECOPD in primary care data alone are very poor. Primary care data alone should not be used to identify hospitalizations for AECOPD. Instead, researchers should use data that are linked to data from secondary care.

Effect of time and day of admission on hospital care quality for patients with chronic obstructive pulmonary disease exacerbation in England and Wales: single cohort study

Objective To evaluate if observed increased weekend mortality was associated with poorer quality of care for patients admitted to hospital with chronic obstructive pulmonary disease (COPD) exacerbation. Design Prospective case ascertainment cohort study. Setting 199 acute hospitals in England and Wales, UK. Participants Consecutive COPD admissions, excluding subsequent readmissions, from 1 February to 30 April 2014 of whom 13 414 cases were entered into the study. Main outcomes Process of care mapped to the National Institute for Health and Care Excellence clinical quality standards, access to specialist respiratory teams and facilities, mortality and length of stay, related to time and day of the week of admission. Results Mortality was higher for weekend admissions (unadjusted OR 1.20, 95% CI 1.00 to 1.43), and for case-mix adjusted weekend mortality when calculated for admissions Friday morning through to Monday night (adjusted OR 1.19, 95% CI 1.00 to 1.43). Median time to death was 6 days. Some clinical processes were poorer on Mondays and during normal working hours but not weekends or out of hours. Specialist respiratory care was less available and less prompt for Friday and Saturday admissions. Admission to a specialist ward or high dependency unit was less likely on a Saturday or Sunday. Conclusions Increased mortality observed in weekend admissions is not easily explained by deficiencies in early clinical guideline care. Further study of out-of-hospital factors, specialty care and deaths later in the admission are required if effective interventions are to be made to reduce variation by day of the week of admission.