Relationship between frequency, length, and treatment outcome of exacerbations to baseline lung function and lung density in alpha-1 antitrypsin-deficient COPD

Patient-Reported Pulmonary Symptoms, Exacerbations, and Management in a Cohort of Patients With Alpha-1 Antitrypsin Deficiency

Rationale

Identifying pulmonary exacerbations in patients with alpha-1 antitrypsin deficiency (AATD) is critical as they are associated with disease progression and poor health-related quality of life. Not all changes in usual respiratory symptoms will be identified as exacerbations by patients with AATD.

Methods

Data collected via regular monthly telephone calls during the first year of the AlphaNet Step Forward Study were analyzed. AlphaNet subscribers were asked about changes in their usual respiratory symptoms, whether they considered changes in symptoms to be pulmonary exacerbations, and their management. Participants who reported changes in their usual respiratory symptoms throughout the year were included in the study. Per-patient and per-event analyses were performed.

Results

Participants (n=316, age 58±10 years, 53% female) reported 797 events of changes in their usual respiratory symptoms in 1 year. Almost half (48%) of these symptom events were identified as pulmonary exacerbations by the study participants. The average number of symptoms was higher in events recognized by participants as exacerbations than those not identified as exacerbations (3.3±1.5 versus 1.8±1.1, respectively). A greater proportion of the exacerbation events were managed by taking antibiotics or corticosteroids or both (81%, 53%, and 41% of the events, respectively). With exacerbations, participants mainly spoke to the pulmonary specialist (39%) or went to the doctor's office (37%). Symptom events not recognized as exacerbations were mostly self-treated (56%).

Conclusions

Changes in usual pulmonary symptoms are not universally recognized as exacerbations. Patients' perspectives in recognizing changes in pulmonary symptoms as exacerbation events are critical.

Management of lung disease in alpha-1 antitrypsin deficiency: what we do and what we do not know

Management of lung disease in patients with alpha-1 antitrypsin deficiency (AATD) includes both non-pharmacological and pharmacological approaches. Lifestyle changes with avoidance of environmental pollutants, including tobacco smoke, improving exercise levels and nutritional status, all encompassed under a disease management program, are crucial pillars of AATD management. Non-pharmacological therapies follow conventional treatment guidelines for chronic obstructive pulmonary disease. Specific pharmacological treatment consists of administering exogenous alpha-1 antitrypsin (AAT) protein intravenously (augmentation therapy). This intervention raises AAT levels in serum and lung epithelial lining fluid, increases anti-elastase capacity, and decreases several inflammatory mediators in the lung. Radiologically, augmentation therapy reduces lung density loss over time, thus delaying disease progression. The effect of augmentation therapy on other lung-related outcomes, such as exacerbation frequency/length, quality of life, lung function decline, and mortality, are less clear and questions regarding dose optimization or route of administration are still debatable. This review discusses the rationale and available evidence for these interventions in AATD.

Exacerbations of Lung Disease in Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency (AATD) is an important risk factor for development of chronic obstructive pulmonary disease (COPD). Patients with AATD classically develop a different pattern of lung disease from those with usual COPD, decline faster and exhibit a range of differences in pathogenesis, all of which may be relevant to phenotype and/or impact of exacerbations. There are a number of definitions of exacerbation, with the main features being worsening of symptoms over at least 2 days, which may be associated with a change in treatment. In this article we review the literature surrounding exacerbations in AATD, focusing, in particular, on ways in which they may differ from such events in usual COPD, and the potential impact on clinical management.

CT densitometry in emphysema: a systematic review of its clinical utility

BACKGROUND

The aim of the study was to assess the relationship between computed tomography (CT) densitometry and routine clinical markers in patients with chronic obstructive pulmonary disease (COPD) and alpha-1 anti-trypsin deficiency (AATD).

METHODS

Multiple databases were searched using a combination of pertinent terms and those articles relating quantitatively measured CT densitometry to clinical outcomes. Studies that used visual scoring only were excluded, as were those measured in expiration only. A thorough review of abstracts and full manuscripts was conducted by 2 reviewers; data extraction and assessment of bias was conducted by 1 reviewer and the 4 reviewers independently assessed for quality. Pooled correlation coefficients were calculated, and heterogeneity was explored.

RESULTS

A total of 112 studies were identified, 82 being suitable for meta-analysis. The most commonly used density threshold was -950 HU, and a significant association between CT density and all included clinical parameters was demonstrated. There was marked heterogeneity between studies secondary to large variety of disease severity within commonly included cohorts and differences in CT acquisition parameters.

CONCLUSION

CT density shows a good relationship to clinically relevant parameters; however, study heterogeneity and lack of longitudinal data mean that it is difficult to compare studies or derive a minimal clinically important difference. We recommend that international consensus is reached to standardize CT conduct and analysis in future COPD and AATD studies.

Hospital readmissions for COPD: a retrospective longitudinal study

Prevention of chronic obstructive pulmonary disease hospital readmissions is an international priority aimed to slow disease progression and limit costs. Evidence of the risk of readmission and of interventions that might prevent it is lacking. We aimed to determine readmission risk for chronic obstructive pulmonary disease, factors influencing that risk, and variation in readmission risk between hospitals across 7.5 million people in London. This retrospective longitudinal observational study included all chronic obstructive pulmonary disease admissions to any hospital in the United Kingdom among patients registered at London general practices who had emergency National Health Service chronic obstructive pulmonary disease hospital admissions between April 2006 and March 2010. Influence of patient characteristics, geographical deprivation score, length of stay, day of week of admission or of discharge, and admitting hospital, were assessed using multiple logistic regression. 38,894 chronic obstructive pulmonary disease admissions of 20,932 patients aged ≥ 45 years registered with London general practices were recorded. 6295 patients (32.2%) had at least one chronic obstructive pulmonary disease readmission within 1 year. 1993 patients (10.2%) were readmitted within 30 days and 3471 patients (17.8%) were readmitted within 90 days. Age and patient geographical deprivation score were very weak predictors of readmission. Rates of chronic obstructive pulmonary disease readmissions within 30 days and within 90 days did not vary among the majority of hospitals. The finding of lower chronic obstructive pulmonary disease readmission rates than was previously estimated and the limited variation in these rates between hospitals suggests that the opportunity to reduce chronic obstructive pulmonary disease readmission risk is small.

A managed reduction of hospital readmissions for London-based chronic lung disease patients may not be needed. Preventing hospital readmissions for patients with chronic obstructive pulmonary disease (COPD) is a key priority to improve patient care and limit costs. However, few data are available to determine and ultimately reduce the risk of readmission. Timothy Harries at King’s College, London, and co-workers conducted a longitudinal study incorporating all COPD admissions into UK hospitals for 20,932 patients registered at London general practitioners between 2006 and 2010. They found that 32% of patients were readmitted within a year, 17.8% within 90 days and 10% within 30 days. Neither age nor geographical deprivation were useful predictors of readmission. These represent lower than estimated levels of readmission, suggesting there may be fewer opportunities to reduce the risk of readmission further.

Length of stay of COPD hospital admissions between 2006 and 2010: a retrospective longitudinal study

Background

Hospitalizations for COPD are associated with poor patient prognosis. Length of stay (LOS) of COPD admissions in a large urban area and patient and hospital factors associated with it are described.

Methods

Retrospective longitudinal study. All COPD patients registered with London general practitioners and admitted as an emergency with COPD (2006–2010), not having been admitted with COPD in the preceding 12 months were included. Association of patient and hospital characteristics with mean LOS of COPD admissions was assessed. Association between hospital and LOS was determined by negative binomial regression.

Results

The total number of admissions was 38,504, from 22,462 patients. The mean LOS for first admissions fell by 0.8 days (95% confidence interval [CI]: 0.7–1.5) from 8.2 to 7.0 days between 2006 and 2010. Seventy-nine percent of first admissions were ≤10 days, with a mean LOS of 3.7 days (2009–2010). The mean LOS of successive COPD admissions of the same patients was the same or less throughout the study period. The interval between successive admissions fell from a mean of 357 days between the first and second admission to a mean of 19 days after eight admissions. Age accounted for 2.3% of the variance in LOS. Socioeconomic deprivation did not predict LOS. Fewer discharges happened at the weekend (1,893/day) than on weekdays (5,218/day). The mean LOS varied between hospitals, from 4.9 days (95% CI: 3.8–5.9) to 9.5 days (95% CI: 8.6–10.3) when adjusting for clustering, age, sex, and socioeconomic deprivation.

Conclusion

The fall in LOS of the first COPD admission between 2006 and 2010 reflects international trends. The stability of LOS in successive admissions suggests that increasing severity of disease does not affect recovery time from an exacerbation. Variations between hospitals of nearly 5 days in LOS for COPD admissions suggests that significant improvements in patient outcomes and in savings in health care utilization could be made in hospitals with longer LOS.