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Objective Although chronic obstructive pulmonary disease (COPD) is a common form of structural lung disease associated with pulmonary non-tuberculous mycobacteria (NTM) infection, no longitudinal studies have investigated the role of NTM in COPD disease progression. Design From 2000 to 2008, spirometry-confirmed COPD patients with sputum specimens sent for mycobacterial cultures were included. Analysis of clinical, microbiological and pulmonary function data was performed. Results The 251 patients were divided into three groups according to the number of NTM isolates: multiple (n = 47), single (n = 63), and no (n = 141) isolates. Mycobacterium avium complex was the most common species in multiple isolates (36.2%) and single isolate (28.6%) groups. Overall, 24.7% of COPD patients had been admitted for exacerbations at least once a year, and patients with multiple and single NTM isolates were more than twice as likely as those with no isolate to experience such exacerbations (38.3% vs. 31.7% vs. 17.0%). After controlling for confounders, patients with multiple NTM isolates had a greater decline in forced expiratory volume in one second than those with single or no isolates (-79.4 ± 32.8 ml vs. -61.6 ± 31.9 ml and -56.2 ± 31.5 ml). Conclusion This study suggests that NTM may play a role in disease progression and deterioration of pulmonary function in COPD patients.

This study examined the complex relationships among recession news, the state of the economy, and people's perceptions toward the economy from January 1987 through March 1996 using trivariate vector autoregression (VAR) analysis. Most of the time-series variables were found to have structural changes during this time frame. With the help of the Chow test, the researchers were able to determine January 1991 as the cut-off point to divide the entire period into two: downturn period and recovery period. The relationships among these three time-series were found to be dramatically different across the two distinct periods. The paper concludes that: (1) the situational factor (different states of economy) played a crucial role in determining how the public evaluates the economy; (2) the extent to which recession news' impact on people's assessment of the economy depended on different economic circumstances; (3) news coverage responded differently across these two distinct periods but, in the long run, followed the economic reality; and (4) the public's sentiments toward the economy can predict economic performance.