Standard set of patient-reported outcomes for personality disorder

People with personality disorder (PD) have problems in functioning of aspects of self and interpersonal dysfunction which lead to emotional distress and impaired social function [1]. With onset early in life [2], high prevalence of over 5% of the general population and 50% in the outpatient psychiatric settings [3], it contributes to a substantial portion of health-care spending [4]. Most of the costs are incurred by inpatient and community mental health care and increased levels of unemployment and lost productivity among people with PD. A variety of psychological and psychosocial interventions have been shown to improve the mental health of people with PD [5‐7]. The wide consensus is that the primary treatment for PD should be outpatient psychosocial therapy, with pharmacological treatment used mainly for the treatment of coexisting conditions. Further recommendation regarding the length and modality of treatments for each trait profile of PD is not clear, differs among countries and are often not in line with the latest research [8]. Compared to other common mental disorders, personality pathology is rarely tracked in routine clinical care. While many settings routinely assess the outcomes of people with depression and anxiety [9], outcome assessment in PD is rare and mostly refers to borderline personality disorders (BPD). In BPD, meta-analyses and reviews highlight the variety of outcomes utilized. Stoffers et al. [10] defined primary outcomes, which included overall BPD severity and BPD symptoms severity; and secondary outcomes, which included psychiatric comorbidity, general distress, global assessment of functioning, attrition/noncompliance with treatment, and adverse events. Lieb et al. [11] used all the outcomes from Stoffers et al. but added hospitalizations, emergency department visits, medication tolerability and side effects. Further outcomes measured in longer-term studies are social and vocational functioning, symptomatic remission and recovery from BPD [12].

In order to establish the value of each treatment for each service user, monitoring of health outcomes is essential. Value of treatment is defined as ‘the outcomes achieved relative to the costs’ [13]. For multiple reasons, measuring outcomes in the mental health is less common and more difficult than elsewhere, in spite of many available and validated health outcomes measures [14]. First of all, measurement precision of instruments might be lower compared to biomarkers. In addition, many instruments are time consuming, and clinicians might lack resources to implement them in busy clinical settings [14]. Also, there are many outcome measures available to measure each domain or symptom, making the results difficult to compare.

ICHOM was established to review the existing outcome measures that matter most to patients and to outline minimum standard sets of outcomes, measurement instruments, timepoints and risk adjustment factors for various conditions [15]. In 2018, ICHOM set out to cover some of the most prevalent mental health conditions. An international, multidisciplinary working group, led by ICHOM, was set up in the end of 2018. Our aim was to define the outcomes that matter most to persons with PD and prepare the standardized set of instruments to measure these outcomes.

As the case for measuring patient outcomes becomes increasingly accepted by clinicians and decision makers in health care, one of the challenges we are faced with is selecting which measures to use from among the vast array of different instruments that could be used. The ICHOM working group for PD responded to this challenge by selecting and defining a standardized minimum set of outcome measures that would be appropriate to use across different cultural and geographical settings [23]. The included outcomes represent those that matter most to people with PD. The measurement of these outcomes across different environments should help to build better communication between patients and providers. Benchmarking of the results should motivate and empower providers to seek and share good practices and improve care and clinical protocols; payers would be able to clearly see the value of care and make informed decisions on strategic purchase strategies [24]. All the outcomes alongside case-mix variables, timepoints for collection and questionnaires are freely available at the ICHOM website (https://​www.​ichom.​org/​standard-sets/​).

ICHOM entered the mental health area in 2018. This area depends to an even higher degree on patient-reported outcomes in comparison with some other clinical areas, where clinical readings can describe the outcomes relatively better. Previous research [25] has shown that defining patient-reported outcomes for PD, particularly BPD has many challenges. BPD has heterogeneous clinical features, meaning that patient-reported outcomes should include broad assessment of psychopathology, but at the same time, measure stable as well as more dynamic aspects of the disorder. Social and occupational functioning are especially salient when assessing the outcomes of people with PD, because a number of studies have shown impaired functioning even when mental health improves [26]. Crawford et al. [27] conducted a Delphi study with service providers, services users and academic experts and similarly established that people with a wide range of PD felt that the most important outcome measure that should be assessed was health-related quality of life, followed by mental health and social functioning. Previous attempt [12] to identify core outcome measures in PD that capture quality of life, functioning and symptoms, highlighted that the number of outcomes for BPD is extensive. Above all, this attempt as well as the guidelines on the development of an agreed set of outcomes measures [26] were focused solely on BPD, while the ICHOM recommended standard set is designed for all those with PD and related mental health conditions.

During the whole working process, lasting between October 2018 and June 2020, many scientists, clinicians and service user representatives were included in the formulation of the standard set. All the members discussed the different steps of the work, from defining the scope to the preparation of the final manuscript. Due to the long period of preparing the final set, there was quite a high degree of fluctuation in the project team, as well as in the working group, but all involved expressed their valuable opinion and contributed effectively to the final outcome. The inclusion of the working group members was, however, based on their work recommendations and limited to people from 17 countries. In spite of extensive literature reviews and use of Delphi processes throughout the project, the results might have differed with a different group of participants from different cultural backgrounds.

The primary aim of the standard set is to reflect outcomes that are important to service users. Therefore, including their views and extensive inputs through the whole process is a strength of this work. There were six service user representatives included in the working group and, in the end, 63 users (among them seven carers or parents) reviewed the final version of the standard set, with 94% saying that all important outcomes are captured in the standard set and 96% saying that it would be useful having these outcomes collected. All of the service user representatives came from developed countries and most of them are from Europe.

The process of data collection via suggested questionnaires represents a significant time burden for service users as well as for clinicians. The participants had this in mind and tried to cover all the outcomes in the standard set with as few instruments as possible. Still, the outcomes in the final standard set are measured by eight instruments and the complete collection of all outcomes lasts up to 30 min (including optional instruments). In many countries, the collection of PROMs is still not supported by information communication technology that would enable more efficient collection of data, less reluctance of the stakeholders and automated analysis and results. ICHOM is working on the information of data collection to support the users of the standard sets. In order to promote the use of the standard set in all international environments, the selected outcomes we chose are already translated into many languages. They are available in multiple formats, easily integrated into diverse data collection tools, are computer adaptive and can be used free of charge. A very important issue in mental health standard sets is comorbidity of PDs with other mental health disorders, such as substance use disorders [28], attention-deficit hyperactivity disorder [29] and schizophrenia [30]. Therefore, harmonization of measures across the mental health standard set, as well as among other standard sets that include the same domains, is an important issue, which was taken into account in the process of the selection of measures.

Available evidence suggests that self-assessed measures made by people with PD have high test–retest reliability [31]. However, concerns have been raised about the reliability of self-reported accounts of aggression and other externalizing behaviours [32]. ICHOM aims to establish person-centred outcomes. However, in recognition of the challenges of relying on self-report measures of aggression, a clinician-rated measure, the Modified Overt Aggression Scale, was selected to measure this outcome.

After undertaking a thorough systematic review, the working group was not able to identify an adequate outcome measure to capture the ‘Coping with Past Experiences of Trauma’ outcome. As the outcome is important to service users, the working group identified the lack of an appropriate instrument as a gap in the currently available outcome measures. Future research should be directed toward defining an appropriate instrument to measure this outcome. Various scales measuring similar constructs, such as ‘Posttraumatic growth’ have been looked at in the process and some of them overlap with ‘Coping with Past Experiences of Trauma’. As such, they might be helpful in defining an appropriate measure in the future. Additionally, discriminatory effects among different types of PD through the Standard Set of this ICHOM endeavour need to be studied further.

Furthermore, the standard set is not seen as fixed but should be updated regularly, following new developments in the clinical environment, as well as developments in the health measurement area. The standard set should be seen as a minimal set of outcomes and instruments for their measurement, and further outcomes and measures could be freely added to this set if needed.

The development of a minimal standard set of value-based service user-centred outcome measures in PD should lead to higher value of care, and better outcomes of care, for people with PD all across the world. Widespread use of these measures will lead to benchmarking and exchange of good practices, to greater inclusion of service users in care processes, and to better communication between clinicians and service users. It will also provide the payer with evidence that could serve as a basis for informed decision making on allocation of funds.