title: [Recruitment difficulties for clinical trials in primary care. When sample size is not reached].
authors.forename: Carles
authors.initials: C
authors.lastname: Llor
authors.forename: Ana
authors.initials: A
authors.lastname: Moragas
mesh_terms: D000465:Algorithms; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D006801:Humans; D018579:Patient Selection; D011320:Primary Health Care; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy; D018401:Sample Size