Descriptive analysis

Of the 176 reviewed studies, 35 (19.9%) were related to individualisation, 79 (44.9%) to personalisation and 62 (35.2%) to person-centredness. The number of publications increased considerably over the years, with 5 (2.8%) published in 2012 and 36 (20.5%) in 2021. The majority were published in Europe and North America, and a major share was identified as primary research. The study characteristics are presented in table 2.

Table 2

Main characteristics of the reviewed studies

Out of 176 articles, 106 (60.2%) provided a conceptualisation or at least a definition of the respective term individualisation, personalisation or person-centredness. Individualisation was defined in 10 studies (28.6%), personalisation in 46 (57.5%) and patient-centredness in 50 (82.0%) articles.

Overall, 84 articles (47.7%) were related to a specific disorder, with a major share (26) on depression and/or anxiety (2631.0%), 17 on psychosis (20.2%) and 9 (10.7%) on dementia. Other somatic disorders were discussed in 10 (11.6%) papers, and other mental disorders (bipolar, attention deficit hyperactivity disorder, autism spectrum disorder, etc) were discussed in 24 (26.2%) studies.

Thematic and linguistic analysesConcepts of individualisation

A major share of the 10 studies that provided definitions or conceptualisations of ‘individualised’ treatment or care was related to psychosis or neurodevelopmental disorders, such as ADHD and autism spectrum disorders. Thematically, the definitions included concepts of the psychological and behavioural dimensions, closely followed by the medical and sociocultural dimensions. No dimension was observed to be predominant.

The behavioural dimension of individualisation discussed individual lifestyle interventions for behavioural changes, for example, targeting the prevention of cardiovascular diseases in patients with psychosis29 or in women with obesity.30 The psychological dimension focused on mental and cognitive functioning and specific symptoms of mental health, for example, in the case of a programme for children:

An Individualised Mental Health Intervention for ASD (AIM HI) clinical intervention and corresponding therapist training protocol were developed. The AIM HI protocol was developed based on a systematic needs assessment of the clinical needs of children with ASD receiving MH services and the training needs of MH therapists.31 (ASD, autism spectrum disorders; MH, mental health)

Moreover, in one study, the role of the individual was contrasted to collectivist values observed in Asian cultures.32 Recognising personhood and the uniqueness of the individual was interpreted here as part of the sociocultural dimension:

Therefore, one’s own thoughts, feelings and interests play the most significant role in defining their goal-directed behaviours and decisions; and not those of the group they are members of (eg, family, religious community).32

Frameworks of individualisation

In the studies defining individualisation, only one framework was found related to this term. The concept of psychotherapy by Carl Rogers33 originally had the title of person-centred or client-centred therapy.34

Co-occurring words of individualisation

In the 1004 abstracts referring to the keyword individualisation, 24 970 words were found and 321 words were included in the network visualisation. As shown in figure 3, abstracts focusing on individualisation show words related to the care system, with programmes, services, exercises and interventions in one cluster (green), gynaecological terms in the blue cluster, and psychiatric terms such as major depression, symptoms, biomarkers and adolescence in the red cluster.

Figure 3

Co-occurrences of words used in 1004 titles and abstracts of studies on individualisation. CAMH, child and adolescent mental health; EBP, evidence-based practice; IDPD, intellectual disability co-occurrent with psychiatric disorders; MTBI, mild traumatic brain injury; PTSD post-traumatic stress disorder.

Concepts of personalisation

A total of 20 out of 46 papers conceptualising personalisation were related to a specific mental disorder, mostly depression. The term ‘personalised’ was shaped by the medical dimension to a certain extent as the most prominent aspects were related to diagnostics, such as personalising an intervention through assessments, methods of digital phenotyping or individual predictors of a disease. The medical dimension also included specific treatment concepts, such as triage, monitoring or individual treatment responses. Cuijpers et al 35 pointed out the prevalence of medical but biological aspects of the concept as well in the context of depression:

And if we really want to develop personalised treatments of depression, we should not only look at individual characteristics of patients and treatments, but also on combinations of characteristics, such as older adults with atypical depression and a specific biomarker. Furthermore, we may want to look at other outcomes, such as side effects of medications, long-term outcomes, patient preferences, and prediction of treatment dropout.35

Treatment-related concepts often referred to the advantage of using new technologies, such as e-mental health applications supported by real-time data collection via mobile phones for the benefit of targeted interventions.36 Some often discussed aspects of the medical dimension were individual health needs, as discussed for example in the context of personalised care planning in line with patients’ preferences and needs.

Concepts of personalisation were also characterised under the biological dimension, especially in articles referring to personalising treatments through biomarkers and gene sequencing.37 38

The psychological dimension was the third prominent category of concepts, with the patient and his or her individual cognitive functions, symptoms of mental health, and preferences and needs in the foreground of considerations:

In psychiatry, the term ‘personalised’ applies to different levels of health-care provision, such as the service organization (accessibility, flexibility, scalability) and the implementation of treatment plans based on the characterization of the individual patient (psychopathological characteristics, personal history including premorbid functioning, family history, individual preferences, environment and lifestyle, physical comorbidities, cognitive functioning, resilience).39

Frameworks of personalisation

Some theoretical frameworks were found using personalisation in a standardised manner. The predictive preventive personalised medicine or the 3PM model40 related to an integrative concept in healthcare that aimed at predicting individual predisposition before the onset of a disease and providing tailored prevention and highly personalised treatments via algorithms.41 Another framework was the RDoC project initiated by the National Institute of Mental Health in 2009 with the aim of improving classification of mental disorders by research domains based on neurobiology and observable behaviour.8 Moreover, the Precision Medicine Initiative of the National Institutes of Health14 was cited in the context of personalisation; however, the study subsumed the term under ‘person-centredness’. One practical framework, the UK governmental initiative ‘Putting People First’ launched in 2007, was also cited,15 which focused on the introduction of personal budgets for adult and social care.

Co-occurring words of personalisation

A total of 1123 abstracts referred to personalisation with 27 980 words, out of which 388 were analysed in VOSViewer. Figure 4 illustrates the network visualisation of word co-occurrences found in articles on personalisation. Again, three clusters were formed, with similar psychiatric terms in the red cluster, treatment-related terms like technology, chatbot, engagement, feedback and adherence in the green cluster, and behavioural terms such as smoking, weight, activity, pain and remotely related occupational stress included in the blue cluster. Some of these terms were connected to ADHD and Alzheimer’s disease with related drugs.

Figure 4

Co-occurrences of words found in 1123 titles and abstracts of studies on personalisation. ADHD, attention deficit hyperactivity disorder; BBT, brief behavioral therapy; BMI, body mass index; DHIS, digital health interventions; FND, functional neurological disorder; HIV, human immunodeficiency virus; PTSD, post-traumatic stress disorder; SPSMS, standard plus personalized SMS.

Concepts of person-centredness

Most of the studies that provided definitions or conceptual aspects of person-centred care were related to dementia and depression and/or anxiety. The highest prevalence of these concepts was in the fields of psychiatry, clinical psychology and psychosomatics (see table 3). Thematically, person-centred care was categorised predominantly in the sociocultural dimension of care, with medical and psychological dimensions as the second and third most prevalently discussed aspects in the literature, respectively. The major conceptual focus of definitions was related to recognising the personhood and individual needs of the service users and shared decision-making between the individual and the caregivers. Within the sociocultural dimension, the concepts of person-centred care emphasised on recognising the individual as unique while providing individualised care and empowering the person for self-determination.

Table 3

Medical fields of application of the reviewed studies using the different terms

Person-centered medicine aims at the promotion of health and well-being of the totality of the person. The person is perceived as the center and goal of health care and the emphasis is shifted from patient to person.42

In the medical dimension, the concepts focused more on the individual’s relationship and interactions with the caregivers for shared decision-making and the unique health needs and experiences of the person.

… a collaborative process between the person and his or her supporters (including the clinical practitioner) that results in the development and implementation of an action plan to assist the person in achieving his or her unique, personal goals along the journey of recovery.43

In the psychological dimension, again the need for recognising the individual preferences and needs was emphasised in the literature, with additional focus on respecting the self-management abilities and autonomy of the individual.

… supporting people to recognize and develop their own strengths and abilities to enable them to live an independent and fulfilling life.44

Some further concepts were categorised in the biological and behavioural dimensions, which are not discussed here (see online supplemental file 2). Additionally, in some papers, an economic dimension to person-centred care concepts was reported.45–47

Frameworks of person-centredness

Most of the frameworks and models were found in the reviewed studies on person-centred care. Kitwood’s model, which we categorised as a theoretical framework, was the most prominent that described five dimensions of personhood.48 Some other frameworks for person-centred care in the studies were those provided by the US Institute of Medicine (2001), which defined it as ‘providing care that is respectful of and responsive to individual patient preferences, needs, and cultural values and ensuring that patient values guide all clinical decisions’49; by the UK Health Foundation, which defined it as ‘a care system that supports us to make informed decisions, helps us to successfully manage our own health and care, and delivers care with respect for our individual abilities, preferences, lifestyles and goals’50; and McCormack’s person-centred practice framework ‘consisting of five domains of macro-context, prerequisites, care environment, person-centred processes, and person-centred outcomes’.51

Co-occurring words of person-centredness

A total of 498 abstracts were related to the term person-centredness with 12 312 words used, of which 206 were chosen for analysis. In figure 5, word co-occurrences in studies on person-centredness show many terms on dementia care, staff, nursing and service use in the red cluster. Psychiatric terms such as depression, anxiety, symptom or guideline, often related to youth and adolescence, are shown in the green cluster. Clinical terms like programme, visit, discharge or care home are shown in the blue cluster.

Figure 5

Co-occurrences of words found in 498 titles and abstracts of studies on person-centredness. PTSL, part-time sick leave; SDS, self-rating depression scale.