Vaidya T, Thomas-Ollivier V, Hug F, et al. - Using the guidelines for cross-cultural adaptation process, researchers tried to translate the recently developed daily and clinical visit PROactive physical activity in COPD (PPAC) instruments (meant for objective quantification of the level of physical activity as well as the difficulties encountered in everyday life) for the French-speaking chronic obstructive pulmonary disease (COPD) community worldwide. They also assessed how weather and pollution could influence the difficulty score. In this study with 117 participants (age 65 ± 9 years; FEV1: 51 ± 20%), the translated clinical visit (C-PPAC) was evaluated in COPD patients in France. Good internal consistency, as well as a good test retest reliability of the French version of C-PPAC, was evident. Lower difficulty score was shown by patients taking long term oxygen therapy, but this score did not correlate with the pollution indices. Overall, findings revealed the acceptance for as well as comprehensibility of the French versions of the questionnaires of the PPAC instruments among COPD patients. Sensitivity to the duration of daylight and rainfall was shown by the difficulty score of C-PPAC. When assessing the physical activity behavior applying these tools in COPD, it is mandatory to take such weather factors into account.