Prevalence and Economic Burden of Bronchiectasis

Microbiologic follow-up study in adult bronchiectasis

There is minimal published longitudinal data about pathogenic microorganisms in adults with bronchiectasis. Therefore a study was undertaken to assess the microbiologic profile over time in bronchiectasis. A prospective study of clinical and microbiologic outcomes was performed. Subjects were assessed by a respiratory physician and sputum sample were collected for analysis. Subjects were followed up and had repeat assessment performed. Eighty-nine subjects were followed up for a period of 5.7+/-3.6 years. On initial assessment the two most common pathogens isolated were Haemophilus influenzae (47%) and Pseudomonas aeruginosa (12%) whilst 21% had no pathogens isolated. On follow-up review results were similar (40% H. influenzae, 18% P. aeruginosa and 26% no pathogens). The prevalence of antibiotic resistance of isolates increased from 13% to 30%. Analysis of a series of H. influenzae isolates showed they were nearly all nontypeable and all were different subtypes. Subjects with no pathogens isolated from their sputum had the mildest disease, while subjects with P. aeruginosa had the most severe bronchiectasis. Many subjects with bronchiectasis are colonized with the same bacterium over an average follow-up of 5 years. Different pathogens are associated with different patterns of clinical disease.

Addition of inhaled tobramycin to ciprofloxacin for acute exacerbations of Pseudomonas aeruginosa infection in adult bronchiectasis

RATIONALE

Pseudomonas aeruginosa lung infection in patients with bronchiectasis, a chronic airway disease that is characterized by episodes of exacerbation, is associated with more severe disease and a higher utilization of health-care resources. Inhaled tobramycin solution reduces the number of acute exacerbations in patients with cystic fibrosis (CF)-related bronchiectasis with P aeruginosa infection but remains untested in the treatment of exacerbations in patients with non-CF bronchiectasis.

OBJECTIVES

This study tested the effect of adding inhaled tobramycin solution to oral ciprofloxacin (Cip) for the treatment of acute exacerbations of non-CF bronchiectasis in patients with P aeruginosa infection.

METHODS

A double-blind, randomized, active comparator, parallel-design study conducted at 17 study centers (5 in the United Kingdom, and 12 in the United States) compared 2 weeks of therapy with Cip with either an inhaled tobramycin solution or placebo in 53 adults with known P aeruginosa infection who were having acute exacerbations of bronchiectasis.

MEASUREMENTS

Clinical symptoms, pulmonary function, clinical efficacy, and sputum microbiology were investigated prospectively.

MAIN RESULTS

An inhaled solution of Cip with tobramycin, compared to placebo, achieved greater microbiological response but no statistically significant difference in clinical efficacy at days 14 or 21. Clinical and microbiological outcomes at the test of cure (ie, the clinical outcome assessment at day 21) were concordant when an inhaled tobramycin solution was added to therapy with Cip and compared to placebo (p = 0.01). Both subject groups had similar overall adverse event rates, but subjects receiving therapy with an inhaled tobramycin solution reported an increased frequency of wheeze (50%; placebo group, 15%).

CONCLUSIONS

The addition of an inhaled tobramycin solution to therapy with oral Cip for the treatment of acute exacerbations of bronchiectasis due to P aeruginosa improved microbiological outcome and was concordant with clinical outcome; the inability to demonstrate an additional clinical benefit may have been due to emergent wheeze resulting from treatment.

Bronchiectasis

Bronchiectasis is generally classified into cystic fibrosis and non-cystic fibrosis bronchiectasis. This review article describes non-cystic fibrosis bronchiectasis in adults. Bronchiectasis can be considered a heterogeneous condition characterized by irreversible airway dilatation with chronic bronchial infection/inflammation. It remains a common condition and is a major cause of respiratory morbidity. Many factors are associated with bronchiectasis, but most commonly patients will have idiopathic disease. Important clinical findings include chronic productive cough, rhinosinusitis, fatigue and bi-basal crackles. Patients have usually had symptoms for many years. Diagnosis is confirmed by high-resolution computed tomography scanning using standardized criteria. Spirometry shows moderate airflow obstruction and there is a high prevalence of bronchial hyperreactivity. The most common pathogens are non-typeable Haemophilus influenzae and Pseudomonas aeruginosa. There may be considerable overlap with other chronic airway diseases. Treatment regimens are still not well defined. Patients tend to have ongoing symptoms and decline in respiratory function despite treatment.

Incidence and Prevalence of Idiopathic Pulmonary Fibrosis

RATIONALE

Idiopathic pulmonary fibrosis is a chronic interstitial lung disease of unknown etiology; its epidemiology in the United States has not been well characterized.

OBJECTIVE

To estimate the annual incidence and prevalence of idiopathic pulmonary fibrosis in the United States.

METHODS

Retrospective cohort design utilizing a large health care claims database spanning the period January 1996 through December 2000.

MEASUREMENTS AND MAIN RESULTS

Persons with idiopathic pulmonary fibrosis were identified based on diagnosis and procedure codes. Using broad case-finding criteria, prevalence was estimated to range from 4.0 per 100,000 persons aged 18 to 34 yr to 227.2 per 100,000 among those 75 yr or older; annual incidence was estimated to range from 1.2 to 76.4 per 100,000. Using narrow case-finding criteria, prevalence ranged from 0.8 to 64.7 per 100,000 persons; comparable figures for incidence were 0.4 to 27.1 per 100,000 persons. Extrapolating these rates to the overall United States' population, prevalence was estimated to be 42.7 per 100,000 (incidence, 16.3 per 100,000) using broad criteria; with narrow criteria, prevalence was estimated to be 14.0 per 100,000 (incidence, 6.8 per 100,000).

CONCLUSIONS

Our results suggest that idiopathic pulmonary fibrosis is probably more common in the United States than previously reported.