Table 1.

Eligibility criteria for nursing homes, residents and nurse specialists

Participants	Eligibility criteria
Nursing homes	All of the following conditions apply: Provides in-patient long-term care services. Provides a minimum of 50 beds. Does not participate in other research projects on prevention of hospital admissions and emergency service utilisation.
Residents	One of the following conditions applies: Receives care services at the care level 3 or higher. Receives care services at the care level 2 and fulfils at least one of the following conditions: …multimorbidity confirmed by suffering from three or more co-existing chronic diseases (DEGAM 2017).39 …hospital admission or utilisation of out-of-hour physician contacts or emergency services within the previous 8 weeks.
Nurse specialists	One of the following conditions applies: Academic qualification (Bachelor degree) and at least 1 year of job practice after professional licensing. 3 years vocational training and additional qualification in geriatric, gerontopsychiatric or palliative care after professional licensing. 3 years vocational training and additional qualification (300 hours cumulative in the last 2 years) after professional licensing. 3 years vocational training and above average performance, assessed by head nurses based on prespecified criteria (eg, knowledge and skills, open-mindedness for innovation and improvement of nursing practice, and personal competencies).40

DEGAM: Deutsche Gesellschaft für Allgemeinmedizin und Familienmedizin e.V. (German association for primary care)³⁹; German care levels (range from 0 to 5) are assessed by expert raters of the German statutory healthcare insurance and can be described as low (0/1/2), medium (3/4), high (5).