Identification of chronic obstructive pulmonary disease subgroups in 13 Asian cities.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition that can differ in its clinical manifestation, structural changes and response to treatment. OBJECTIVE: To identify subgroups of COPD with distinct phenotypes, evaluate the distribution of phenotypes in four related regions and calculate the 1-year change in lung function and quality of life according to subgroup. METHODS: Using clinical characteristics, we performed factor analysis and hierarchical cluster analysis in a cohort of 1676 COPD patients from 13 Asian cities. We compared the 1-year change in forced expiratory volume in one second (FEV1), modified Medical Research Council dyspnoea scale score, St George's Respiratory Questionnaire (SGRQ) score and exacerbations according to subgroup derived from cluster analysis. RESULTS: Factor analysis revealed that body mass index, Charlson comorbidity index, SGRQ total score and FEV1 were principal factors. Using these four factors, cluster analysis identified three distinct subgroups with differing disease severity and symptoms. Among the three subgroups, patients in subgroup 2 (severe disease and more symptoms) had the most frequent exacerbations, most rapid FEV1 decline and greatest decline in SGRQ total score. CONCLUSION: Three subgroups with differing severities and symptoms were identified in Asian COPD subjects.

Gaps in using bronchodilators, inhaled corticosteroids and influenza vaccine among 23 high- and low-income sites.

BACKGROUND: Increasing access to essential respiratory medicines and influenza vaccination has been a priority for over three decades. Their use remains low in low- and middle-income countries (LMICs), where little is known about factors influencing use, or about the use of influenza vaccination for preventing respiratory exacerbations. METHODS: We estimated rates of regular use of bronchodilators, inhaled corticosteroids and influenza vaccine, and predictors for use among 19 000 adults in 23 high-income countries (HICs) and LMIC sites. RESULTS: Bronchodilators, inhaled corticosteroids and influenza vaccine were used significantly more in HICs than in LMICs, after adjusting for similar clinical needs. Although they are used more commonly by people with symptomatic or severe respiratory disease, the gap between HICs and LMICs is not explained by the prevalence of chronic obstructive pulmonary disease or doctor-diagnosed asthma. Site-specific factors are likely to influence use differently. The gross national income per capita for the country is a strong predictor for use of these treatments, suggesting that economics influence under-treatment. CONCLUSION: We still need a better understanding of determinants for the low use of essential respiratory medicines and influenza vaccine in low-income settings. Identifying and addressing these more systematically could improve the access and use of effective treatments.

Evaluation of transbronchial lung biopsy specimens in the diagnosis of bronchiolitis obliterans after lung transplantation.

We investigated the utility of transbronchial lung biopsy in allograft evaluation, particularly with reference to rejection-mediated bronchiolitis obliterans in 105 transplant recipients surviving 3 months or more (29 single lung, 76 double lung). A sensitivity and specificity of one transbronchial biopsy procedure with an average procurement of 7.6 tissue fragments was 17.1% and 94.5%, respectively, according to results obtained from biopsies carried out after 2 months transplantation in 29 patients with confirmed rejection-mediated bronchiolitis obliterans and 61 patients known not to have the disease. The predictive value of a positive procedure for the presence of disease was 65.5% and that of a negative procedure for the absence of disease was 65.2%. Similarly, the sensitivity and specificity for the finding of bronchiolar mural fibrosis were 18.5% and 85.3%, respectively; and, for lymphocytic bronchiolitis, the values were 1.9% and 100%, respectively. We conclude that, although the sensitivity of transbronchial biopsy and the predictive value of a procedure which shows microscopic bronchiolitis obliterans are low, attempts should be made to support a clinical diagnosis of bronchiolitis obliterans through biopsy, given the problems inherent in achieving an early and certain diagnosis according to clinical criteria alone.