Assessments, diagnostic criteria and outcome measures for growing pains and persistent pain in the presence of restless leg syndrome in children: a scoping review

Abstract

Objective

To identify the assessments, diagnostic criteria and outcome measures reported in peer-reviewed literature for children with growing pains and persistent lower limb pain in the presence of restless leg syndrome (RLS).

Study design

Scoping review completed in line with Joanna Briggs Institute methodological guidance

Data sources

Five online databases were searched—MEDLINE, Embase, CINAHL, PsycINFO and AMED—for records up to 14 October 2024.

Eligibility criteria

Records reporting on the use of assessments, diagnostic criteria or outcome measures in children (aged 0–18 years) with growing pains or persistent lower limb pain in the presence of RLS. Articles were required to have a sample size of ≥10 and be available in English language.

Data extraction and synthesis

Data were extracted by two independent reviewers and analysed using descriptive statistics.

Results

Following review of 19 806 records, 61 unique records were included. Most were observational cross-sectional or case–control designs. Assessments were varied and primarily focused on body functions and pain characteristics rather than activities and participation. There were 15 unique diagnostic criteria reported for growing pains with limited consistency and sometimes conflict between included items. Outcomes measures were only reported in eight records and typically measured pain presence and intensity.

Conclusions

Assessment and subsequent diagnosis of growing pains and persistent pain in the presence of RLS lack consistency. Outcome measures were seldom used as most records were not designed to measure change over time. Standardised practices for assessment and management of these conditions may benefit clinicians and optimise patient care.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• Comprehensive review of available literature due to high search yield.

• Alignment of assessments and outcome measures to International Classification of Functioning, Disability and Health: child and youth version domains demonstrates historic focus on body structures and functions.

• Methodological quality of the included studies was not assessed; however, the objective of the review was to chart available literature irrespective of quality.

Introduction

Children commonly report nocturnal leg pain, which can be variable in the length of time it presents.¹ Families often seek advice from health professionals when it is persistent and results in distress and impact on sleep.^{2 3} In the absence of clear underlying disease, this is often clinically labelled as ‘growing pains’.⁴ Growing pains are typically described as benign, bilateral, intermittent pain in the muscles or around lower limb joints with no abnormalities on physical examination or laboratory testing.^{2 5} Although benign, growing pains is a complex phenomenon characterised by a lack of understanding regarding the aetiology and pathophysiology, and disagreements concerning terminology and definition, particularly in the absence of a confirmed association with growth.^{6 7}

A clear definition of the condition is further complicated by researchers questioning if there is a link between growing pains and restless leg syndrome (RLS).⁸,¹⁰ RLS is a sensorimotor disorder characterised by a strong urge to move the legs, often significantly affecting sleep.¹¹ Current diagnostic criteria for RLS describe sensations as ‘uncomfortable’ and ‘unpleasant’, but the presence of pain is not required for the diagnosis of RLS.¹¹ Despite this, there are reports in the literature that some children describe persistent lower limb pain accompanying RLS, with some authors classifying this as a distinct phenotype of the condition (eg, RLS-Painful).^{12 13} However, some studies of children with RLS also report parents describing concomitant ‘growing pains’.^{9 14 15} These inconsistencies in the terminology used to describe nocturnal leg pain in children provide no clear delineation between growing pains and pain in the presence of RLS. Therefore, it is challenging to determine whether these conditions are similar yet separate clinical entities or could represent a spectrum of one disorder.

Children impacted by growing pains or painful RLS frequently seek the care of medical and allied health professionals (AHPs); however, the management of growing pains has limited focused research. Small studies have trialled interventions, including muscle stretching, in shoe padding or vitamin D supplementation, while expert opinions and clinical reviews typically recommend massage, parental reassurance or use of analgesic medication.^{34 16},¹⁹ There are no known guidelines for physical examination to guide the exclusion of other conditions known to cause lower limb pain or when additional invasive testing is necessary. There is also limited guidance for clinicians to select measures of treatment outcomes. Consequently, children with growing pains and persistent lower limb pain in the presence of RLS and their families may not receive consistent evidence-based care.

To assist the future development of clinical practice recommendations, the aim of this scoping review was to collate the assessments health professionals use to make a diagnosis, the diagnostic criteria and outcome measures of treatment success reported in studies, including children with growing pains and persistent lower limb pain in the presence of RLS. This information can form the foundation of guidance for health professionals to improve consistent care for families and children who experience nocturnal leg pain.

Methods

Protocol and registration

This scoping review was conducted in accordance with the Joanna Briggs Institute methodology guidance for scoping reviews.²⁰ It is reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR),²⁰ with a checklist available as online supplemental appendix 1. A protocol for this review was prospectively registered on Open Science Framework on 28 August 2023 (https://doi.org/10.17605/OSF.IO/RDQVP).

Scope of the review

At its inception, this review was intended to encompass a broad spectrum of paediatric lower limb pain conditions which could be considered under the general term ‘chronic primary musculoskeletal pain’. Chronic primary musculoskeletal pain was defined using the International Association for the Study of Pain description of pain located in the muscles, bones, joints or tendons which has persisted for more than 3 months and is associated with significant emotional distress and/or functional disability, and the pain is not better accounted for by another condition.²¹ The inclusion of conditions within the search terms was informed by a recent Delphi panel where experts in the field of paediatric pain categorised children’s lower limb pain conditions as either chronic primary or secondary musculoskeletal pain.²² Four conditions reached consensus for categorisation as chronic primary musculoskeletal pain, including ‘growing pains’, ‘musculoskeletal pain’ (a banner term including ‘regional fibromyalgia’, ‘chronic musculoskeletal pain’, ‘idiopathic pain’) and persistent lower limb pain in the presence of ‘restless leg syndrome’ and ‘functional neurological disorder’.²² As this is a relatively new classification, alternate terminologies for chronic pain not associated with another diagnosis were also included such as ‘idiopathic pain’, ‘functional pain’ and ‘non-organic pain’.

The registered protocol and search strategy detailed below reflect the intention to review all conditions categorised as chronic primary musculoskeletal pain. Once full-text screening was completed, it was determined by the research team that the volume of records retrieved was too large to be meaningfully synthesised in a single scoping review. Therefore, we have focused on reporting the results relating to ‘growing pains’ and ‘persistent lower limb pain in the presence of RLS in this review.

Eligibility criteria

Initially, records were eligible for inclusion if they reported on the assessment, use of diagnostic criteria or outcome measurement in children (0–18 years) with chronic primary musculoskeletal pain. Assessments were defined as examinations or tests used to gain information about a participant at one timepoint, whereas outcome measures were used to measure change in a particular variable over time. Following the alterations to the protocol, only records reporting growing pains and persistent lower limb pain in the presence of RLS were eligible. In records with mixed populations, only data from participants that met this review’s eligibility criteria were included, and the record was excluded if this was not able to be extracted separately from non-eligible data. There were no limitations on research setting, geographic location or other contextual factors.

Primary research records were included, as well as case series with a sample size >10 that included any outcomes of interest in the eligible population. Systematic reviews, narrative reviews, opinion pieces, editorials and records with a sample size of <10 were excluded. Qualitative records were included if they reported on the primary outcomes. Records in languages other than English were excluded.

Information sources and search

A full search strategy was developed in consultation with a university librarian and five online databases were searched, including Ovid MEDLINE, Ovid Embase, Ovid AMED, CINAHL and Ovid PsycINFO. The initial search was conducted on 21 November 2023 and updated on 14 October 2024, searching from database inception up to this date. The search strategy included multiple terms for chronic primary musculoskeletal pain impacting the lower limb such as ‘growing pains’, ‘fibromyalgia’ and ‘regional fibromyalgia’, ‘idiopathic pain’ and ‘functional pain’, as well as search terms for a paediatric population such as ‘child’, ‘adolescent’ and ‘p$ediatric’. A comprehensive search strategy was used to gather relevant articles to ensure the broadest number of research papers were identified. The search strategy, including identified key words, index terms and MeSH headings, was adapted for each database. The full electronic search strategy for all databases is presented in online supplemental appendix 2.

Source of evidence selection

Following the search, all identified records were collated and uploaded into EndNote 20 (Clarivate Analytics, Pennsylvania, USA) and then exported into Covidence Systematic Review Software (Veritas Health Innovation, Melbourne, Australia) where duplicates were removed. Titles and abstracts were screened by two of three independent reviewers (MS, JC and LMD) against the eligibility criteria, with conflicts screened by a third reviewer (CMW). Full texts were screened independently by two of four independent reviewers (MS, JC, LMD and CMW). Forward and backward chaining of citations from included articles was completed by one reviewer (MS), with eligible articles from this process included for data extraction. Reasons for exclusion of full text records were recorded and reported in the PRISMA-ScR flow diagram, generated using the Shiny app.²³

Data charting process and data items

Data from eligible records were double extracted by two of five reviewers (MS, VP, LMD, EI and CMW) using a data extraction spreadsheet developed by the research team in Microsoft Excel.²⁴ Data items included author name, year of publication, study design, participant age and sex and/or gender, description of all assessments, diagnostic criteria and outcome measures relevant to growing pains or RLS, anatomical location of pain and health professionals involved in care. Sex and/or gender was only extracted where data for the review population were discretely reported, that is, not combined with a control group. Age data were extracted for both the whole sample and the population of interest where reported. Where two records reported data from the same cohort, these were collapsed into one record with data points only tallied once to avoid over-representation.

Synthesis of results

Data were summarised descriptively using frequencies and percentages where applicable (ie, study and participant characteristics and reported assessments or outcome measures). To describe the study participants, combined means and SDs were calculated where records reported age data for sex and/or gender separately. Assessments and outcome measures were categorised under broad headings of ‘Subjective’, ‘Objective’ or ‘Laboratory tests and imaging’ assessments or outcomes. Assessments and outcome measures were charted against the domains of the International Classification of Functioning, Disability and Health: child and youth version (ICF-CY).²⁵ The use of each diagnostic criteria was tallied, as well as the inclusion of individual items within each criteria set. Where records created their own diagnostic or inclusion criteria, this was named after the primary author of the record.

Patient and public involvement

This research is part of a larger project with a steering committee, including patient representatives. Findings from this research are planned to be disseminated to the public and healthcare providers.

Results

In total, 19 806 records were identified through database searching. After removal of duplicates and title and abstract screening, 649 records were retrieved for full-text screening. An additional 3885 records were identified from forward and backward chaining of included articles, of which 181 full texts were deemed relevant for full-text screening. Following full-text screening, 62 records were considered eligible for inclusion in the review (figure 1). Two records reported on identical participant cohorts^{26 27}; hence, data were combined, with 61 unique records in the final yield. The most common reason for exclusion was that records did not explicitly describe lower limb involvement in pain or did not specify that participants had chronic primary musculoskeletal pain (ie, pain may have been associated with another underlying disease).

Figure 1. Flow diagram of selection of sources of evidence. AMED, Allied and Complementary Medicine Database; CINAHL, Cumulative Index to Nursing and Allied Health Literature; Embase, Excerpta Medica Database; MEDLINE, Medical Literature Analysis and Retrieval System Online.

A summary of the characteristics of the included studies is shown in table 1 and detailed information in online supplemental appendix 55. Included records were primarily cross-sectional or case–control designs. There were 7992 children with growing pains included across 60 records and 259 children with persistent pain in the presence of RLS across 11 records, with 10 of these including cohorts of both conditions. Of the 36 records that reported sex of participants, males (n=2747) and females (n=2634) were relatively evenly represented. All records reported on age data for the entire population included. The age of included participants with growing pains and/or persistent lower limb pain in the presence of RLS was reported in 36/61 (59.0%) records, ranging from 1 to 18 years, with all other studies reporting age for a broader sample only.

Table 1. Characteristics of the included studies.

	n/61 (%)
Study type
Cross-sectional	34 (55.7)
Case–control	13 (21.3)
Prospective cohort	7 (11.5)
Retrospective cohort	6 (9.8)
Qualitative interviews	2 (3.3)
Case series	2 (3.3)
Randomised controlled trial	1 (1.6)
Pre-post	1 (1.6)
Quasi experimental	1 (1.6)
Country
Australia	11 (18.0)
The USA	8 (13.1)
Turkey	5 (8.2)
Israel	5 (8.2)
Italy	4 (6.6)
India	4 (6.6)
The UK	4 (6.6)
Other	21 (34.4)
Condition
Growing pains	50 (82.0)
Persistent lower limb pain in the presence of restless leg syndrome	1 (1.6)
Both	10 (16.4)
Health professionals involved in care
Paediatrician	14 (23.0)
Developmental paediatrician	1 (1.6)
Paediatric rheumatologist	11 (18.0)
Paediatric orthopaedic surgeon	6 (9.8)
Paediatric sleep physician	4 (6.6)
Paediatric neurologist	3 (4.9)
Community physician/general practitioner	2 (3.3)
Paediatric psychiatrist	2 (3.3)
Paediatric endocrinologist	1 (1.6)
Paediatric haematologist	1 (1.6)
Medical specialist (unspecified)	1 (1.6)
Doctor (unspecified)	1 (1.6)
Chiropractor	2 (3.3)
Podiatrist	1 (1.6)
Physiotherapist	1 (1.6)
Nurse	1 (1.6)

Subjective assessments to guide diagnosis

A full list of assessments is provided in online supplemental appendix 4. Subjective assessments were reported in 51/61 (83.6%) records, primarily related to the clinical characteristics of pain, and most commonly assessed by using non-validated questionnaires and clinical interviews. The pain constructs most frequently reported were location (28/51, 54.9%), frequency and timing (25/51, 49.1%) and duration (14/51, 27.5%). 14 studies used validated tools, most frequently the University of South Australia Growing Pains Questionnaire (4/14, 28.6%)²⁸,³¹ and Wong-Baker FACES Pain Rating Scale (3/14, 21.4%).^{28 31 32} Reports of children with RLS more frequently reported on the child’s qualitative description of RLS sensations (8/11, 72.7%). Other subjective measures focused on the impact of pain on the child, including impact on sleep (17/51, 33.3%), activities of daily living (7/51, 13.7%), measured using child or parent-reported questions and school attendance (6/51, 11.8%), typically measured by number of days absent.

Objective assessments to guide diagnosis

Objective measures were reported in 41/61 (66.7%) records. Anthropometric data, including height and weight (23/41, 56.1%) and body mass index (13/41, 31.7%), were the most common constructs collected during physical examinations. There were few validated objective assessments used, including the Beighton score of joint hypermobility (6/41, 14.6%)²⁸³³,³⁷ and pGALS - paediatric gait, arms, legs, spine (1/61, 2.4%).³⁸ A broad collation of neurological responses, including strength, tone, reflexes and sensation, was reported in 6/41 (14.6%) records.^{834 39},⁴²

Laboratory tests and imaging to guide diagnosis

Laboratory tests were reported in 25/61 (41.0%) records, with 42 unique tests reported. Erythrocyte sedimentation rate (8/25, 32.0%), serum vitamin D (8/25, 32.0%), complete blood count (7/25, 28.0%) and alkaline phosphatase (7/25, 28.0%) were most frequently reported. Ferritin (3/11, 27.3%) was the most commonly reported laboratory test in records of persistent lower limb pain in the presence of RLS. Imaging and other diagnostic tests were reported in 18/61 (29.5%) records, most frequently X-ray (6/18, 33.3%), polysomnography (4/18, 22.2%) and MRI (2/18, 11.1%) were used.

Diagnostic criteria

Diagnostic criteria for ‘growing pains’ were reported in 37/60 (61.7%) records which reported on the condition. The diagnostic criteria reported for each included record are provided in online supplemental appendix 4. The most frequently reported were criteria described by Peterson in 1986⁶ (14/37, 37.8%),126 27 31 32 35 37 43,⁵⁰ followed by Evans and Scutter in 2004¹ (4/37, 10.8%)²⁸,³⁰⁴¹ and Champion et al in 2012⁵¹ (3/37, 8.1%).⁵¹,⁵³ Peterson’s description of growing pains has been adapted several times to create unique diagnostic criteria, with varying additions such as the impact on physical activity in Evans’ 2008 criteria,² or pain starting between the ages of 3 and 12 years in Champion and colleagues’ 2012 criteria.⁵¹ A number of records also generated their own criteria which do not appear to have been otherwise replicated.⁵⁴,⁵⁸ Clinical diagnosis without specified criteria was reported in 14/60 (23.3%) records,833 34 36 42 59,⁶⁷ while 5/60 (8.3%) records reported children or parents self-reporting growing pains.¹⁴⁶⁸,⁷¹ Items in each of the reported diagnostic criteria are provided in online supplemental appendix 3.

Persistent lower limb pain in the presence of RLS was self-reported by participants in all 11 relevant records using descriptors such as ‘ache’, ‘hurts’ or ‘pain’.⁸¹²,15 39 42 69 RLS was primarily diagnosed using the National Institute of Health (NIH) 2003 Workshop criteria for RLS in children (8/11, 72.7%)812 14 15 39 69,⁷¹ or the updated International Restless Leg Syndrome Study Group (IRLSSG) 2013 criteria (2/11, 18.2%).^{13 72} One record used novel criteria based on the NIH Workshop 2003 criteria, which was created due to a lack of direct translation into Polish language.⁴² This criterion differs from both the NIH and IRLSSG criteria by including ‘pain’ in the description of sensations associated with RLS. Additionally, one record (1/11, 9.1%) used the NIH 2003 criteria for children below the age of 13 and adult RLS criteria for those 13 and above.⁷¹

Outcome measures

A full list of outcome measures is provided in online supplemental appendix 6. Outcome measures to describe the impact of treatment were reported in 8/61 (13.1%) records.1618 32 45 58 63 73,⁷⁵ All eight records focused on growing pains. The most common subjective outcomes included the Visual Analogue Scale for pain intensity (3/8, 37.5%), with others relating to the absence of symptoms (3/61, 37.5%) or a pain diary (2/8, 25.0%). Two objective outcomes were reported: the use of dolorimetry to measure pain pressure thresholds (1/8, 12.5%) and a measure of static and dynamic balance using specialised equipment (1/8, 12.5%). Laboratory testing was reported as an outcome measure in three records, specifically serum levels of vitamin D (3/8, 37.5%), parathyroid hormone (2/8, 25.0%) and alkaline phosphatase (2/8, 25.0%).

Aligning assessments and outcome measures to ICF domains

Table 2 shows how assessments and outcome measures in included records correspond to the ICF-CY domains. The majority of both assessments and outcome measures were categorised as ‘body functions’ as this included characteristics of pain, some physical examination findings and many laboratory tests.

Table 2. Alignment of assessments and outcome measures to the ICF domains.

	n (%)*
Subjective assessments (N=95)
Body functions	50 (52.6)
Activities and participation	22 (23.2)
Personal factors	16 (16.8)
Environmental factors	9 (9.5)
Body structures	4 (4.2)
Objective assessments (N=106)
Body functions	74 (69.8)
Body structures	32 (30.2)
Activities and participation	1 (0.9)
Subjective outcome measures (N=9)
Body functions	9 (100)
Objective outcome measures (N=6)
Body functions	5 (83.3)
Body structures	1 (16.7)

^*Subcategories may not sum to 100% as some assessments span multiple ICF domains.

ICF, International Classification of Functioning, Disability and Health.

Discussion

This scoping review identified significant inconsistency in the diagnostic criteria, assessments and outcome measures being used for children with growing pains and persistent lower limb pain in the presence of RLS. All but one of the 11 records reporting on persistent lower limb pain in the presence of RLS also reported on growing pains. In some, these were concurrent diagnoses, whereas some reported the conditions as mutually exclusive groups. It is not within the scope of this research to provide insight into where growing pains and RLS intersect in their aetiology and clinical presentation, and there remain conflicting views on how to consider these conditions in relation to each other.⁸,¹⁰¹² While pain was the primary consideration within diagnosis, assessment and outcome measurement in growing pains, it remains sparsely measured and poorly understood in RLS. Assessments used by researchers were primarily linked to body functions and structures. This was also observed in the small number of outcome measures. Laboratory testing and imaging were often used in records of children with growing pains to exclude organic disease, particularly markers of possible inflammatory disease. However, this was infrequently reported for children with persistent lower limb pain in the presence of RLS. Researchers were not primarily focused on pain during research on children with RLS; therefore, pain was not well described. Contrastingly, clinical characteristics of pain were the most frequently reported assessments for children with growing pains, although measures and descriptors of pain lacked consistency across records. While there are published diagnostic criteria for growing pains, the included studies commonly modified these with the addition of assessment items intending to support the diagnosis of growing pains or exclude underlying disease through physical examination or other investigation.

Our findings are not the first to note conflicting use of diagnostic criteria and working definitions of growing pains in research with the poor consistency between included studies. Of particular note is a 2022 scoping review, which examined terminology, definitions and diagnostic criteria in studies containing text referring to growing pains, including author opinions, n=1 articles or narrative reviews.⁶ In this review, O’Keeffe and colleagues concluded there is ‘no clarity’ in the available literature on how growing pains is defined.⁶ Our review only included records with participants with growing pains or persistent lower limb pain in the presence of RLS. This enabled us to capture, more specifically, the use of diagnostic criteria in research and practice, demonstrating a slightly more consistent inclusion of items in growing pains criteria such as intermittent pain episodes (54% in this review vs 42% in O’Keeffe et al),⁶ pain in the evening or night (49% vs 48%)⁶ and bilateral pain (48% vs 31%).⁶ However, there remains a lack of consistent application of diagnostic criteria for growing pains, with 15 unique criteria used across included records within research and practice within this current review. Even with attempts to standardise growing pains diagnostic criteria by various research groups, one clear definition and criteria have not been accepted by the research and health professional community.

The majority of included records were cross-sectional, and therefore were not designed to measure change over time or employ the use of outcome measures. Only six records assessed the impact of an intervention. When researchers did measure change over time, they primarily selected outcomes focused on presence and severity of pain. We were surprised to find no outcome measures used to understand the impact of treatments on psychosocial or activity-related factors. This finding was particularly concerning given the well-established impacts of chronic pain on daily function for children, particularly in the domains of sleep, physical activity and school absenteeism.^{76 77} Growing pains may not limit a child’s ability to be physically active due to their presence primarily at night; however, they are highly likely to disturb sleep, which can have an impact on school attendance, performance and participation with peers.⁷⁸ These are important metrics that give a broad insight into the child’s quality of life. No records reported the use of outcome measures for persistent lower limb pain in the presence of RLS. Improvement in pain was typically not a measured outcome in treatment studies for paediatric RLS, although this may be recognised as part of overall improvement.⁷⁹ Overall, outcome measure use was limited in growing pains and persistent lower limb pain in the presence of RLS, providing little guidance for health professionals on what could be used in clinical practice.

Health professional involvement was primarily medical, with very limited allied health representation in included records. Multidisciplinary care involving AHPs is known to have positive effects on pain intensity, functional disability and emotional health in children with various chronic pain diagnoses, while children with lower limb pain also often seek care from AHPs such as podiatrists and physiotherapists.^{80 81} This was not reflected in the included records, although comprehensive detail of all professionals involved in the care of participants was not reported in most records. The role of AHPs in the care of children with growing pains and persistent lower limb pain in the presence of RLS spans diagnosis, assessment and treatment. Distinguishing between growing pains, considered to be a benign and self-limiting condition, and other presentations requiring escalation and specialist referral is part of the AHPs’ role. AHPs are often limited in their ability to order laboratory tests and imaging depending on profession and jurisdiction, leaving assessment to subjective questioning and physical examination. The results of this review do not reveal a clear outline of this subjective or objective assessment for growing pains and persistent lower limb pain in the presence of RLS. This presents a challenge to the clinician in the selection of appropriate assessment tools.

The strength of this scoping review was the yield of records within the search strategy, which enabled a comprehensive review of available literature. This was particularly important because of the various ways researchers described growing pains. While a limitation of this review may be that an assessment of methodological quality was not performed, this review primarily focused on the breadth of diagnostic criteria, assessments and outcome measures being used and therefore quality of the included records was not considered to have a significant impact on the synthesis of the results. Future research, including effectiveness of treatment, should be subject to methodological quality assessment where the scope of the question is narrowed. Authors were not contacted for additional or missing information as this review aimed to evaluate only data which were published and available. Relevant data may have also been missed with the exclusion of clinical reviews and records with <10 participants, although this is not expected to have had a significant impact on the findings of the review given the large number of studies included.

Conclusion

The use of assessments and outcome measures in the included records was disparate and primarily focused on body functions rather than daily activities and participation. Growing pains and persistent lower limb pain in the presence of RLS were not consistently reported as discrete conditions, and based on current knowledge should not be considered interchangeable. While diagnostic criteria for growing pains often contained similar items, no definitive criteria have been established and applied to clinical populations. Future research should aim to develop consensus on the diagnosis and establish consistent assessment and outcome measures for both research and clinical use.

Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information.