Respirology : official journal of the Asian Pacific Society of Respirology
-
Although randomization provides a gold-standard method of assessing causal relationships, it is not always possible to randomly allocate exposures. Where exposures are not randomized, estimating exposure effects is complicated by confounding. The traditional approach to dealing with confounding is to adjust for measured confounding variables within a regression model for the outcome variable. ⋯ These estimated propensity scores can then be used in various ways-matching, stratification, covariate-adjustment or inverse-probability weighting-to obtain estimates of the exposure effect. In this paper, we provide an introduction to propensity score methodology and review its use within respiratory health research. We illustrate propensity score methods by investigating the research question: 'Does personal smoking affect the risk of subsequent asthma?' using data taken from the Tasmanian Longitudinal Health Study.
-
Comparative Study
Impact of pulmonary hypertension on exercise performance in patients with interstitial lung disease undergoing evaluation for lung transplantation.
Pulmonary hypertension (PH) is a known complication in patients with interstitial lung disease (ILD). Cardiopulmonary exercise testing (CPET) is an essential tool for the assessment of patients with cardiac and pulmonary diseases due to its prognostic and therapeutic implications. Few studies have evaluated the relationship between CPET response and mean pulmonary artery pressures (mPAP) in ILD. The purpose of the present study was to determine and compare the potential correlations between CPET, 6-min walk test (6MWT), pulmonary function testing (PFT) and PH in patients with ILD being evaluated for lung transplantation. ⋯ This is the first study that analyses 6MWD, PFT and CPET in patients with ILD awaiting lung transplantation with and without PH. The present study demonstrates the significant impact of PH on exercise capacity and performance in patients with ILD awaiting lung transplantation.
-
Early diagnosis of chronic obstructive pulmonary disease (COPD) in primary care settings is difficult to achieve chiefly due to lack of availability of spirometry. This study estimated the prevalence of airflow limitation among chronic smokers using a handheld spirometer in this setting. ⋯ In a primary care setting, handheld spirometry (COPd-6) found a prevalence of airflow limitation of ∼10% in smokers. Patients were older, not overweight and had an ill-defined history of health problems.
-
Multicenter Study Comparative Study
Diagnostic performance comparison of the Chartis System and high-resolution computerized tomography fissure analysis for planning endoscopic lung volume reduction.
Endobronchial valve (EBV) therapy is optimized in patients who demonstrate little or no collateral ventilation (CV). The accuracy of the Chartis System and visual assessment of high-resolution computerized tomography (HRCT) fissure completeness by a core radiology laboratory for classifying CV status was compared by evaluating the relationship of each method with target lobe volume reduction (TLVR) after EBV placement. ⋯ When evaluating patients for likelihood of successful EBV therapy, the Chartis System CV assessment and HRCT fissure analysis appear to have comparable accuracy. Both techniques were found to be beneficial for EBV procedure planning.
-
The soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is a promising diagnostic marker for many types of infections. A bivariate meta-analysis was performed to evaluate its diagnostic value for lower respiratory tract infections (LRTI). We searched PubMed, Cochrane Library and Web of Science (from January 1966 to August 2013) for all trials assessing diagnostic value of sTREM-1 for LRTI. ⋯ The Q* of sTREM-1 for distinguishing culture-positive LRTI from culture-negative diseases was 0.79, and the area under SROC curve was 0.86. Current evidence suggests that sTREM-1 is an accurate marker of LRTI. The overall diagnostic value of sTREM-1 for LRTI, community-acquired LRTI and hospital-acquired LRTI is similar.