Effect of an interprofessional care concept on the hospitalization of nursing home residents: study protocol for a cluster-randomized controlled trial. - Piotrowski, Alexandra; Meyer, Martha; Burkholder, Iris; Renaud, Dagmar; Müller, Markus Alexander; Lehr, Thorsten; Laag, Sonja; Meiser, Joachim; Manderscheid, Lisa; Köberlein-Neu, Juliane (Trials, 2020)