Impact of switching to new spirometric reference equations on severity staging of airflow obstruction in COPD: a crosssectional observational study in primary care.

Background: Severity of airflow obstruction in chronic obstructive pulmonary disease (COPD) is based on forced expiratory volume in one second expressed as percentage predicted (FEV1%predicted) derived from reference equations for spirometry results.

Aims: To establish how switching to new spirometric reference equations would affect severity staging of airflow obstruction in the Dutch primary care COPD patient population.

Methods: Spirometry tests of 3,370 adults aged >40 years with obstruction (postbronchodilator FEV1/forced vital capacity (FVC) <0.

Lung function decline in relation to diagnostic criteria for airflow obstruction in respiratory symptomatic subjects.

Background: Current COPD guidelines advocate a fixed < 0.70 FEV1/FVC cutpoint to define airflow obstruction. We compared rate of lung function decline in respiratory symptomatic 40+ subjects who were 'obstructive' or 'non-obstructive' according to the fixed and/or age and gender specific lower limit of normal (LLN) FEV1/FVC cutpoints.

Effect of e-learning and repeated performance feedback on spirometry test quality in family practice: a cluster trial.

Purpose: Spirometry has become an indispensable tool in primary care to exclude, diagnose, and monitor chronic respiratory conditions, but the quality of spirometry tests in family practices is a reason for concern. Aim of this study was to investigate whether a combination of e-learning and bimonthly performance feedback would improve spirometry test quality in family practices in the course of 1 year.

Methods: Our study was a cluster trial with 19 family practices allocated to intervention or control conditions through minimization.

An expert-supported monitoring system for patients with chronic obstructive pulmonary disease in general practice: results of a cluster randomised controlled trial.

Objective: To investigate the long-term effectiveness of a general practice monitoring system with respiratory expert recommendations for general practitioners' management of patients with chronic obstructive pulmonary disease (COPD), compared with usual care.

Design, Settings And Participants: A multicentre randomised controlled trial of patients with COPD, clustered by general practices; 200 participants were recruited to maintain at least 75 participants per group for analysis. The trial took place from July 2005 to February 2008 in the south-western region of the Netherlands.