Twiss J, McKenna SP, Graham J, Swetz K, Sloan J, Gomberg-Maitland M. Applying Rasch analysis to evaluate measurement equivalence of different administration formats of the activity limitation scale of the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR). Health Qual Life Outcomes. 2016 Apr 9;14(1):57. doi: 10.1186/s12955-016-0462-2.
Cima K, Twiss J, Speich R, McKenna SP, Grunig E, Kahler CM, Ehlken N, Treder U, Crawford SR, Huber LC, Ulrich S. The German adaptation of the Cambridge pulmonary hypertension outcome review (CAMPHOR). Health Qual Life Outcomes. 2012 Sep 13;10:110. doi: 10.1186/1477-7525-10-110