## 1 Introduction  
Since the 1880s, Western healthcare systems have successfully and primarily focused on acute diseases, the reduction of deaths, and the treatment and prevention of such conditions [1]. However, presently healthcare systems in Western countries are facing several challenges due to aging populations; increasing amounts of chronically ill citizens; continuous accumulation of information and data and innovations in clinical practice and technology [2]. Consequently, a paradigm shift in healthcare is slowly evolving, which entails a shift from a heavy focus on deadly diseases and acute conditions, towards a heavier emphasis on chronic illness and patient's health-related quality of life (HRQoL) [3]. On top of this, a new type of patient is emerging, demanding adequate information, and active participation when managing their health [2]. Therefore, new healthcare measures, value-basedhealthcare, standardization of data, coordination of patient pathways, and more holistic healthcare systems are focal subjects in current healthcare [4; 5; 6]. It is within this complex context, Patient-reported outcome (PRO) is anticipated to be an advantageous instrument, on an individual level as part of clinical practice or on a population level as part of research and preventive healthcare [7]. Thus, PROs are spreading horizontally across sectors and disease areas and vertically across organizational levels, widening its functionality [8]. An evolvement especially made possible by PROs digitalization, supported by current health data policies regarding themes such as e.g., \"the patient as an active partner\", \"health by and with people\", \"knowledge on time\", \"prevention\" and \"a health knowledge commons\" [9; 10]. A common definition of PRO was coined by the American Food and Drug Administrations (FDA) in 2009, as part of their \"Guidance for Industry\" report, where PRO is considered: \"Any report of the status of patient's health condition that comes directly from the patient, without interpretation of the patient's response by a clinician or anyone else\" [11]. A definition making it clear that PRO concerns patients' health condition, reported directly by the patient; however, the phrase 'any report'; allows flexible interpretations of a PROs actual content as this remains quite unclear. However, a full read of the white paper, reveals that PRO, according to FDA, mainly is an instrument used in clinical trials when testing drugs [11]. Hence, the report \"does not address the use of PRO instruments for purposes beyond the evaluation of claims made about a medical product in labeling\" [FDA]; meaning that patient-oriented and disease management purposes are not included in this description of PRO. Patient-reported outcome measures (PROMs) are applied when measuring patients' health conditions and belongs under the umbrella term patient-reported data. Other types of data in this category are patient-reported experience measures (PREMs), used to assess the quality of care based on patient's satisfaction and surveys based on patient-reported data [7]. The different scopes of PREM and PROM mean they act as complementary tools when evaluating the quality of healthcare [12]. The term PROM is typically used when PRO is considered a measure or when referred to as a questionnaire. Examples of frequently used PROM questionnaires are the five-item World Health Organization Well-Being Index (WHO-5) and Short Form-36 (SF-36), which measures patients' well-being and HRQoL, respectively [13; 14]. The WHO-5 questionnaire is used to calculate patients well-being over the last two weeks on a six-point Likert scale by asking patients to consider the following statements: (a) I have felt cheerful and in good spirit, (b) I have felt calm and relaxed, (c) I have felt active and vigorous, (d) I woke up feeling fresh and rested, (e) My daily life has been filled with things that interest me [13].