A conceptual framework for reporting experience of physical activity in COPD
Authors: Enrico M. Clini, Laura Fregonese
Journal: European Respiratory Journal (2014)

PROs integrate patients' perspective into clinical/regulatory assessment; conceptual framework adds new information http://ow.ly/AqXrOThe importance of physical activity in chronic diseases is increasingly acknowledged.The amount of physical activity has been shown to predict mortality indirectly in patients suffering from multiple conditions [1], while physical inactivity is important predictor of the risk of hospital readmission, and associated with higher mortality in elderly [2] and in patients with chronic obstructive pulmonary disease (COPD) [3,4].However, even though physical activity represents one of the most intriguing extrapulmonary clinical aspects of patients suffering from COPD, there is little evidence that either pharmacological or nonpharmacological interventions (e.g.counselling and rehabilitation) can enhance and durably maintain increased levels of physical activity in COPD or, conversely, that an increase in physical activity would result in favourable outcomes relevant to COPD patients [5].Methods quantifying physical activity objectively, such as portable and wearable devices to monitor daily activities, are available and will allow further research on physical activity in COPD, and on its relation to the progression of the disease and the response to treatment [6][7][8].COPD is traditionally measured by lung function, mainly forced expiratory volume in 1 s (FEV1) and the FEV1/forced vital capacity ratio.FEV1 correlates poorly with important symptoms such as breathlessness and with the impact of the disease on daily life in COPD [9]; it is therefore important to complement lung function assessment with measures directly related to the patients' experience of the disease, such as patientreported outcomes (PROs), for a comprehensive evaluation of the disease.''PRO'' is an umbrella term covering single and/or multidimensional measures of symptoms, health-related quality of life (HRQoL), health status, adherence to treatment, satisfaction, etc. [10].The importance of PROs for regulatory purposes, according to the US Food Drug Administration (FDA), is based on: 1) some treatment effects are known only to the patient; 2) there is a desire to know the patients' perspective on the effectiveness of a treatment; and 3) systematic assessment of the patients' perspective may provide valuable information that can be lost when that perspective is filtered through a clinician's evaluation [11].The article by DOBBELS et al. [12] in this issue of the European Respiratory Journal presents the initial results of the Innovative Medicines Initiative-funded PROactive project (www.proactiveCOPD.com),aimed at developing PROs capturing the dimension of physical activity in COPD, mainly for use clinical trials.The authors describe the methodological process leading to two new PRO instruments in stable patients with COPD, one for daily use and one for site visits.The three-step qualitative study (one-to-one interviews, focus groups and cognitive debriefing) included 116 patients from four different countries.Three main