@article{3102735,
    title = "Validity and responsiveness of the Daily-and Clinical visit-PROactive Physical Activity in COPD (D-PPAC and C-PPAC) instruments",
    author = "Garcia-Aymerich, J. and Puhan, M.A. and Corriol-Rohou, S. and De Jong, C. and Demeyer, H. and Dobbels, F. and Erzen, D. and Frei, A. and Gimeno-Santos, E. and Hopkinson, N.S. and Ivanoff, N. and Karlsson, N. and Louvaris, Z. and Polkey, M.I. and Rabinovich, R.A. and Scuri, M. and Tabberer, M. and Vogiatzis, I. and Troosters, T.",
    journal = "Thorax",
    year = "2021",
    volume = "76",
    number = "3",
    pages = "228-238",
    publisher = "BMJ Publishing Group",
    issn = "0040-6376, 1468-3296",
    doi = "10.1136/thoraxjnl-2020-214554",
    keywords = "adult;  age distribution;  Article;  chronic obstructive lung disease;  clinical visit proactive physical activity instrument;  construct validity;  controlled study;  daily proactive physical activity instrument;  disease exacerbation;  disease severity;  dyspnea;  exercise;  female;  forced expiratory volume;  human;  internal consistency;  major clinical study;  male;  personal experience;  physical activity;  population distribution;  psychometry;  pulmonary rehabilitation;  quality of life;  randomized controlled trial;  reliability;  respiratory tract disease assessment;  retrospective study;  self report;  sex difference;  validation study;  chronic obstructive lung disease;  clinical trial;  exercise tolerance;  follow up;  kinesiotherapy;  multicenter study;  pathophysiology;  physiology;  procedures;  prospective study;  quality of life;  questionnaire, Exercise;  Exercise Therapy;  Exercise Tolerance;  Follow-Up Studies;  Forced Expiratory Volume;  Humans;  Prospective Studies;  Psychometrics;  Pulmonary Disease, Chronic Obstructive;  Quality of Life;  Surveys and Questionnaires",
    abstract = "Background The Daily-PROactive and Clinical visit-PROactive Physical Activity (D-PPAC and C-PPAC) instruments in chronic obstructive pulmonary disease (COPD) combines questionnaire with activity monitor data to measure patients' experience of physical activity. Their amount, difficulty and total scores range from 0 (worst) to 100 (best) but require further psychometric evaluation. Objective To test reliability, validity and responsiveness, and to define minimal important difference (MID), of the D-PPAC and C-PPAC instruments, in a large population of patients with stable COPD from diverse severities, settings and countries. Methods We used data from seven randomised controlled trials to evaluate D-PPAC and C-PPAC internal consistency and construct validity by sex, age groups, COPD severity, country and language as well as responsiveness to interventions, ability to detect change and MID. Results We included 1324 patients (mean (SD) age 66 (8) years, forced expiratory volume in 1 s 55 (17)% predicted). Scores covered almost the full range from 0 to 100, showed strong internal consistency after stratification and correlated as a priori hypothesised with dyspnoea, health-related quality of life and exercise capacity. Difficulty scores improved after pharmacological treatment and pulmonary rehabilitation, while amount scores improved after behavioural physical activity interventions. All scores were responsive to changes in self-reported physical activity experience (both worsening and improvement) and to the occurrence of COPD exacerbations during follow-up. The MID was estimated to 6 for amount and difficulty scores and 4 for total score. Conclusions The D-PPAC and C-PPAC instruments are reliable and valid across diverse COPD populations and responsive to pharmacological and non-pharmacological interventions and changes in clinically relevant variables. © Author(s) (or their employer(s)) 2021."
}