Criteria and recruitment
mental illness
RECRUITMENT, RECRUITMENT
The recruitment for convenience samples took place from April 2020 to September 2021 at the orthopaedic departments with stratification at the national level and with blocks of unknown size (ranging from 1 to 3). Recruitment was closed due to the lockdown of elective surgery by the COVID-19 pandemic. For the feasibility test (IA), eight patients fulfilling the inclusion criteria (and meeting none of the exclusion criteria) were included with their six staff members. However, in case of major app adjustments, it would be necessary to repeat the 1A part and include more participants. For the validation (1B), we aimed to include ten other patients for the apps in each country; altogether, 30 patients and their staff members.All staff had two to four of training sessions each per app. The inclusion criteria were adult patients scheduled for hip or knee arthroplasty with daily smoking, risky drinking, or both. Exclusion criteria were not being able to give informed consent (e.g., being less than 18 years old, having a severe mental illness, not understanding the national language), acute surgery, withdrawal of consent, being pregnant or lactating, not having or being able to press the buttons, or otherwise use a smartphone/tablet.