Is kinesiophobia and pain catastrophising at baseline associated with chronic pain and disability in whiplash-associated disorders? A systematic review

Prognostic factors of pain, disability, and poor outcomes in persons with neck pain - an umbrella review

OBJECTIVE

The aim of this study was to identify prognostic factors pertaining to neck pain from systematic reviews.

DATA SOURCES

A search on PubMed, Scopus, and CINAHL was performed on June 27, 2024. Additional grey literature searches were performed.

REVIEW METHODS

We conducted an umbrella review and included systematic reviews reporting the prognostic factors associated with non-specific or trauma-related neck pain and cervical radiculopathy. Prognostic factors were sorted according to the outcome predicted, the direction of the predicted outcome (worse, better, inconsistent), and the grade of evidence (Oxford Center of Evidence). The predicted outcomes were regrouped into five categories: pain, disability, work-related outcomes, quality of life, and poor outcomes (as "recovery"). Risk of bias analysis was performed with the ROBIS tool.

RESULTS

We retrieved 884 citations from three databases, read 39 full texts, and included 16 studies that met all selection criteria. From these studies, we extracted 44 prognostic factors restricted to non-specific neck pain, 47 for trauma-related neck pain, and one for cervical radiculopathy. We observed that among the prognostic factors, most were associated with characteristics of the condition, cognitive-emotional factors, or socio-environmental and lifestyle factors.

CONCLUSION

This study identified over 40 prognostic factors associated mainly with non-specific neck pain or trauma-related neck pain. We found that a majority were associated with worse outcomes and pertained to domains mainly involving cognitive-emotional factors, socio-environmental and lifestyle factors, and the characteristics of the condition to predict outcomes and potentially guide clinicians to tailor their interventions for people living with neck pain.

Reply to Kovacs, F.M.; Seco-Calvo, J. Limitations of a Cross-Sectional Correlation Study. Comment on "Elabd et al. Prediction of Back Disability Using Clinical, Functional, and Biomechanical Variables in Adults with Chronic Nonspecific Low Back Pain. J. Clin. Med. 2024, 13, 3980"

Herein, we reply to comments made by Kovacs and Seco-Calvo [...].

Higher Neck Pain Intensity and Pain Catastrophizing Soon After A Whiplash Injury Partially Explain the Presence of Persistent Headache: A Prospective Study

OBJECTIVE

To understand whether pain-related factors soon after a whiplash injury can explain the presence of chronic headache.

MATERIALS AND METHODS

A prospective study with a follow-up of 6 months was performed, including 42 patients with acute whiplash-associated disorders. Neck pain intensity, the Neck Disability Index, the Tampa Scale of Kinesiophobia, the Pain Catastrophizing Scale, and the Anxiety State-Trait Scale were assessed at baseline. Differences in clinical characteristics between those with and without headache at 6 months were determined. The relative risk of presenting with headache was evaluated. A logistic regression model was performed to assess which factors at baseline could explain the presence of headache at 6 months.

RESULTS

At 6 months, one-third of the sample presented with chronic headache. Significant differences were found for several outcome measures when people with and without headache were compared ( P <0.001). The highest relative risk of presenting with headache was found for moderate/severe levels of pain catastrophizing during the acute phase (RR=15.00, 95% CI=3.93, 57.22). The level of neck pain intensity and pain catastrophizing at baseline partially explained the presence of headache at 6 months ( R2 =0.627).

DISCUSSION

The risk of presenting with persistent headache attributed to a whiplash injury is increased when people present with higher neck pain intensity and pain catastrophizing soon after a whiplash injury. Evaluating neck pain intensity and pain catastrophizing at baseline may assist in identifying those more likely to develop chronic headache, potentially providing an opportunity for early targeted interventions.

Network analyses reveal the interaction between physical features, fear of movement and neck pain and disability in people with acute and chronic whiplash-associated disorders

BACKGROUND AND OBJECTIVE

A network analysis can be used to quantitatively assess and graphically describe multiple interactions. This study applied network analyses to determine the interaction between physical and pain-related factors and fear of movement in people with whiplash-associated disorders (WAD) during periods of acute and chronic pain.

METHODS

Physical measurements, including pressure pain-thresholds (PPT) over neural structures, cervical range of motion, neck flexor and extensor endurance and the cranio-cervical flexion test (CCFT), in addition to subjective reports including the Tampa Scale of Kinesiophobia (TSK-11), Neck Disability Index (NDI) and neck pain and headache intensity, were assessed at baseline in 47 participants with acute WAD. TSK-11, NDI and pain intensity were assessed for the same participants 6 months later (n = 45). Two network analyses were conducted to estimate the associations between features at baseline and at 6 months and their centrality indices.

RESULTS

Both network analyses revealed that the greatest weight indices were found for NDI and CCFT at baseline and for neck pain and headache intensity and NDI and TSK-11 at both time points. Associations were also found betweeen cervical muscle endurance and neck pain intensity in the acute phase. Cervical muscle endurance assesssed during the acute phase was also associated with NDI after 6 months - whereas PPT measured at baseline was associsated with headache intensity after 6 months.

CONCLUSION

The strongest associations were found for headache and neck pain intensity and neck disability and fear of movement, both during acute pain and when mesured 6 months later. The extent of neck endurance and measures of PPT at baseline may be associated with neck disability and headache, respectively, 6 months after a whiplash injury.

SIGNIFICANCE

Through two network analyses, we evaluated the interaction between pain-related factors, fear of movement, neck disability and physical factors in people who had experienced a whiplash injury. We demonstrated that physical factors may be involved in the maintenance and development of chronic pain after a whiplash injury. Nevertheless, the strongest associations were found for headache and neck pain intensity and neck disability and fear of movement, both during acute and chronic phases.

Integrating jigsaw puzzle thinking into practice: the assessment of cervical spine radiculopathy

PURPOSE OF REVIEW

Cervical spine radiculopathy (CSR) presents a complex socioeconomic problem for patients, clinicians, families, employers and healthcare systems. Due to the heterogeneity of clinical presentation and underlying mechanisms, clinical assessment can be challenging. This review will examine the literature on the underlying pathophysiology and studies investigating the holistic assessment strategies for this disabling condition. The authors will focus particular attention on the psychological factors associated with CSR and the physical and imaging strategies to establish a diagnosis.

RECENT FINDINGS

Contemporary CSR assessment should identify the underlying pathomechanisms and how this may impact the somatosensory nervous system integrity and function. No physical assessment test in isolation will establish CSR diagnosis; therefore, clinicians should utilise a cluster of tests and recognise the potential limitations as part of a clinical reasoning framework. The assessment of the somatosensory nervous system can provide insights into particular subgroups of CSR presentation, which may provide interesting opportunities to continue to enhance individualised assessment and management strategies for CSR. The interplay between psychological factors can influence the diagnosis and recovery times for a person with CSR, and clinicians should continue to explore how these factors may influence a person's prognosis. The authors will discuss the opportunities for future research and limitations of contemporary approaches to assessment, underpinned by evidence, and how this supports a clinical assessment to establish CSR diagnosis.

SUMMARY

Research should continue to investigate how clinicians assess the interplay between physical and psychological factors to inform the establishment of CSR. Specifically, there is a need to investigate the validity and reliability of combining somatosensory, motor and imaging assessment findings to reach a diagnosis and inform onward management plans.

Don't Throw the 'Bio' out of the Bio-Psycho-Social Model: Editorial for Spine Rehabilitation in 2022 and Beyond

Spinal injuries, disorders and disabilities are among the leading causes for work loss, suffering, and health care expenditures throughout the industrialized world [...].

The development and measurement properties of the Dutch version of the fear-avoidance components scale (FACS-D) in persons with chronic musculoskeletal pain

OBJECTIVES

The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument assessing different constructs related to the fear-avoidance model of pain. The aim was to translate the original English FACS into Dutch (FACS-D) and assess its measurement properties in persons with chronic musculoskeletal pain.

METHODS

The original English FACS (20 item-scale, range: 0-100) was translated in Dutch through standard forward-backward translation methodology. The FACS-D's measurement properties were evaluated in 224 persons with chronic musculoskeletal pain. Internal consistency, test-retest reliability and measurement error were assessed with the Cronbach's alpha coefficient (α), intraclass correlation coefficient (ICC), and standard error of measurement (SEM). Construct validity was assessed through inter-item correlation analyses, exploratory factor analysis, association with other fear-avoidance-related constructs, and hypothesis testing.

RESULTS

Internal consistency, test-retest reliability and hypotheses testing were good (α=0.92; ICC=0.92, CI 0.80-0.96; 7/8 hypotheses confirmed). Similar to the original FACS and other translated versions, a two-factor model best fit the data. However, the item distribution differed from other versions. One factor represented "pain-related cognitions and emotions" and a second factor represented "avoidance behaviour." In contrast to the original FACS, low inter-item correlations for item 12 were found. The FACS-D was more strongly associated with fear-avoidance-related constructs of pain severity, perceived disability, feelings of injustice, and depressive/anxiety symptoms than the other fear-avoidance-related scales studied here.

CONCLUSIONS

The FACS-D demonstrated good reliability and construct validity, suggesting that it may be a useful measure for Dutch-speaking healthcare providers. Two clinically relevant factors, with a different item distribution than the original FACS, were identified: one covering items on pain-related cognitions and emotions, and one covering items on avoidance behaviour. The stronger association between FACS-D and fear-avoidance related constructs suggests that the FACS-D may be more effective in evaluating the cognitive, emotional and behavioural constructs of pain-related fear-avoidance than other similar measures.

Clinical phenotypes and prognostic factors in persons with hip osteoarthritis undergoing total hip arthroplasty: protocol for a longitudinal prospective cohort study (HIPPROCLIPS)

BACKGROUND

Large heterogeneity exists in the clinical manifestation of hip osteoarthritis (OA). It is therefore not surprising that pain and disability in individuals with hip OA and after total hip arthroplasty (THA) cannot be explained by biomedical variables alone. Indeed, also maladaptive pain-related cognitions and emotions can contribute to pain and disability, and can lead to poor treatment outcomes. Traumatic experiences, mental disorders, self-efficacy and social support can influence stress appraisal and strategies to cope with pain, but their influence on pain and disability has not yet been established in individuals with hip OA undergoing THA. This study aims (1) to determine the influence of traumatic experiences and mental disorders on pain processing before and shortly after THA (2) to identify preoperative clinical phenotypes in individuals with hip OA eligible for THA, (3) to identify pre- and early postoperative prognostic factors for outcomes in pain and disability after THA, and (4) to identify postoperative clinical phenotypes in individuals after THA.

METHODS

This prospective longitudinal cohort study will investigate 200 individuals undergoing THA for hip OA. Phenotyping variables and candidate prognostic factors include pain-related fear-avoidance behaviour, perceived injustice, mental disorders, traumatic experiences, self-efficacy, and social support. Peripheral and central pain mechanisms will be assessed with thermal quantitative sensory testing. The primary outcome measure is the hip disability and osteoarthritis outcome score. Other outcome measures include performance-based measures, hip muscle strength, the patient-specific functional scale, pain intensity, global perceived effect, and outcome satisfaction. All these measurements will be performed before surgery, as well as 6 weeks, 3 months, and 12 months after surgery. Pain-related cognitions and emotions will additionally be assessed in the early postoperative phase, on the first, third, fifth, and seventh day after THA. Main statistical methods that will be used to answer the respective research questions include: LASSO regression, decision tree learning, gradient boosting algorithms, and recurrent neural networks.

DISCUSSION

The identification of clinical phenotypes and prognostic factors for outcomes in pain and disability will be a first step towards pre- and postoperative precision medicine for individuals with hip OA undergoing THA.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05265858. Registered on 04/03/2022.

The Relationship Between Pain-Related Psychological Factors and Maximal Physical Performance in Low Back Pain: A Systematic Review and Meta-Analysis

Theoretical frameworks explain how pain-related psychological factors may influence the physical performance. In this systematic review and meta-analysis, we evaluated the evidence regarding the relationship between the pain-related psychological factors and the maximal physical performance in patients with low back pain (LBP). Pubmed, Embase, CINAHL and Web of Science databases were searched from inception to May 2022. Cross-sectional or longitudinal studies reporting cross-sectional measures of association between at least one pain-related psychological factor and a quantitatively measured outcome of maximal physical performance in patients with LBP were eligible for inclusion. Thirty-eight studies (n = 2,490; 27 cross-sectional studies, n = 1,647 (66%); 11 longitudinal studies, n = 843 (34%)) were included, with 92% of participants (n = 2,284) having chronic LBP. Results showed that pain-related fear, pain catastrophizing, and anticipated pain were consistently and negatively associated with the maximal physical performance in chronic LBP, whereas pain-self efficacy showed positive correlations. Overall, magnitudes of absolute pooled r-values were small (r ≤ 0.25), except for anticipated pain, which was moderately associated with maximal physical performance (r = -0.34 to -0.37). Subanalyses and sensitivity analyses yielded similar pooled correlation coefficients. Certainty of evidence using the GRADE recommendations was very low to moderate for pain-related fear, and very low to low for the other pain-related psychological factors. Prospero registration: CRD42021227486. PERSPECTIVE: Overall, small pooled correlation coefficients were shown between pain-related psychological factors and maximal physical performance in chronic LBP. Certainty of evidence was very low to low for all pain-related psychological factors other than pain-related fear. Future studies taking into account limitations of the current literature may therefore change these conclusions.

A systematic review shows minimal evidence for measurement properties of psychological functioning outcomes in whiplash

OBJECTIVES

The aim of this study was to systematically identify, synthesize, and appraise studies on the measurement properties of patient-reported outcome measures (PROMs) for anxiety, depression, fear of movement, pain catastrophizing, post-traumatic stress, self-efficacy, and stress in people with whiplash-associated disorders (WAD).

STUDY DESIGN AND SETTING

PsycINFO, MEDLINE, EMBASE, CINAHL, PILOTS, Web of Science, and Scopus were searched (November 9, 2021). Studies evaluating any measurement property of relevant PROMs in WAD were included. Two reviewers independently screened the studies and assessed the measurement properties in accordance with the COSMIN guidelines.

RESULTS

Measurement properties of 10 PROMs were evaluated in WAD: Pictorial Fear of Activity Scale-Cervical (PFActS-C), Tampa Scale of Kinesiophobia-11, Pain Catastrophizing Scale (PCS), Pain Self-Efficacy Questionnaire (PSEQ), PSEQ-4 item, PSEQ-2a, PSEQ-2b, Self-Efficacy Scale, Harvard Trauma Questionnaire, and Post-Traumatic Stress Diagnostic Scale. Content validity was not examined in any of these PROMs in whiplash. Moderate- or high-quality evidence showed adequate internal structure for the PSEQ, PCS, and PFActS-C, whereas the original structures of the remaining seven PROMs were not confirmed in whiplash.

CONCLUSION

Until further research on the measurement properties of these PROMs is available, researchers may opt to use the PSEQ, PCS, or PFActS-C if the construct is aligned with research aims.

Higher Neck Pain Intensity and the Presence of Psychosocial Factors Are More Likely When Headache is Present after a Whiplash Injury: A Case-Control Study

BACKGROUND

Several factors such as neck pain intensity, disability, anxiety, depression, female sex, or a previous history of headache are associated with post-whiplash headache. However, the possible role of psychosocial factors contributing to the presence of headache or worsening of headache after a whiplash trauma remains unclear. To address this gap in knowledge, there is the need to assess psychosocial factors concerning headache shortly after a whiplash injury.

OBJECTIVE

To evaluate psychological features, pain and disability in people with acute whiplash associated disorders (WAD) and compare these features between those with and without headache.

DESIGN

Case-control study.

SETTING

A secondary care traumatology center.

METHODS

Forty-seven people with acute WAD were recruited; 28 with headache, and 19 without. All participants completed self-reported questionnaires including Visual Analogue Scale (VAS) for neck pain intensity, the Neck Disability Index (NDI), Pain Catastrophizing Scale (PCS), Tampa Scale Kinesiophobia-11 (TSK-11), and State-Trait Anxiety Inventory.

RESULTS

Neck pain intensity (P < .001), neck disability (P < 0.001), pain catastrophizing (P < .001), kinesiophobia (P < .001), and anxiety state (P = .007) and trait (P = .05) were higher in those with headache when compared to those without. In addition, high levels of neck pain (P = .025), moderate levels of neck disability (P < .001), moderate levels of pain catastrophizing (P = .015), and moderate (P = .002) and severe (P = .016) levels of kinesiophobia were related to the presence of headache.

CONCLUSIONS

The level of neck pain intensity and disability, kinesiophobia, catastrophizing, and anxiety were all greater in people with acute WAD who presented with a headache compared to those without headache.

Influence of kinesiophobia on pain intensity, disability, muscle endurance, and position sense in patients with chronic low back pain-a case-control study

Background

Patients with chronic low back pain (CLBP) frequently present with kinesiophobia. Though large body of evidence reported the impact of kinesiophobia in patients with CLBP, there are paucity of studies in associating kinesiophobia to muscle endurance and position sense in patients with CLBP. The primary aim of the study is to compare the impact of kinesiophobia on lumbar extensor endurance, position sense in patient with CLBP, and asymptomatic individuals. Secondarily, we aim to examine the association between kinesiophobia and lumbar extensor endurance, position sense, pain intensity, and functional ability in patients with CLBP. Thirdly, we aim to assess the degree of association of various factors on CLBP, lumbar endurance, and position sense.

Material and methods

This case-control study will have 200 patients with CLBP and 400 controls. Kinesiophobia, lumbar endurance, and lumbar position sense will be assessed with Tampa Scale, Soren’s lumbar extensor test, and lumbar repositioning test respectively. Secondarily, the pain intensity will be assessed with visual analog scale and functional ability with Patient-specific Functional Scale in patients with CLBP. Lumbar endurance and joint position sense will be compared between subjects with and without kinesiophobia. Kinesiophobia scores will be compared with lumbar extensor endurance and proprioception joint position errors, pain intensity, and functional ability. Simple and multiple binary logistic regression will be used to determine crude and adjusted odd’s ratio for kinesiophobia, lumbar position sense and kinesiophobia, and lumbar endurance.

Discussion

The finding from this study can be generalized as this study has adequate sample size and subgroup analysis by adjusting the variables to draw a valid conclusion. The finding of this study will help the working physician to include assessment of kinesiophobia as part of musculoskeletal evaluation for patient with CLBP in a prospective diagnostic intervention.

Trial registration

ClinicalTrials.gov NCT05079893. Registered on 14 October 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06406-6.

Negative Psychological Factors' Influence on Delayed Onset Muscle Soreness Intensity, Reduced Cervical Function and Daily Activities in Healthy Participants

We examined the influence of negative psychological factors (catastrophizing, distress and kinesiophobia) on delayed onset muscle soreness (DOMS) intensity, cervical function (strength and range of motion) and on daily activities (ADL), and the suitability of an exercise protocol designed to induce DOMS within the cervical region. Psychological factors and cervical function were assessed in 86 healthy participants at baseline before applying a DOMS provocation protocol in the cervical flexor muscles. After 24hour, cervical function was reassessed. In addition, at 24hour and 48hour, the intensity of DOMS and its impact on ADL were assessed using the visual analog scale (VAS). The protocol was effective given that it generated low-moderate intensity DOMS (VAS≈30 -40mm) and a statistically significant reduction in cervical strength and range of motion. Psychological distress (anxiety and depression), but not kinesiophobia and catastrophism, predicted a loss of cervical strength (explained 43% of the variance) and range of motion (explained 22% of the variance) after induction of DOMS. In addition, participants' anxiety level predicted DOMS intensity at 24hour (explained 19% of the variance). PERSPECTIVE: The present findings highlight the relevance of evaluating psychological distress as a preventive/therapeutic measure, given that high levels of distress could lead to more intense and disabling pain in acute injuries, and all these aspects are considered risk factors for the chronification of symptoms.

Kinesiophobia and related factors in cancer patients with TIAPs during the long term: a cross-sectional survey

OBJECTIVE

This study is designed to investigate the status of kinesiophobia and related factors in cancer patients with totally implantable venous access ports (TIAPs).

METHODS

This is a cross-sectional study; all the participants were recruited from the Oncology Department and the Daytime Chemotherapy Center, Renji Hospital, Shanghai Jiao Tong University School of Medicine, from April 1 to May 31, 2021. The participants were interviewed by researchers using the self-made general information questionnaire and the Tampa Scale of Kinesiophobia-11 (TSK-11) scale, which allows the fear of movement to be quantified. Eligible patients were aged ≥ 18 years, confirmed with cancer, and implanted with a port. The logistic regression model was used to evaluate clinical factors and the risk of kinesiophobia.

RESULTS

A total of 282 patients were recruited (aged 58.0 ± 11.5 years), of which gastrointestinal cancer accounted for 54.6%, breast cancer accounted for 22.7%, lung cancer accounted for 11.3%, and other types accounted for 11.3%. The TSK-11 score of the 282 patients was 17.84 ± 6.06 points, 45.7% of the patients reported mild kinesiophobia (TSK-11 ≥ 18), 18.4% of the patients reported moderate to severe kinesiophobia (TSK-11 ≥ 25), and the highest score reached 34 points. Results of logistic regression analysis showed that exercise habits (P = 0.025), pain (P = 0.023), and foreign body sensation (P = 0.003) were the risk factors of kinesiophobia.

CONCLUSION

Kinesiophobia is common in cancer patients with TIAPs, and it is closely related to the subjective experience of daily activities, which requires more attention and early intervention to reduce the potential adverse effects.

Understanding the Psychological, Physiological, and Genetic Factors Affecting Precision Pain Medicine: A Narrative Review

PURPOSE

Precision pain medicine focuses on employing methods to assess each patient individually, identify their risk profile for disproportionate pain and/or the development of chronic pain, and optimize therapeutic strategies to target specific pathological processes underlying chronic pain. This review aims to provide a concise summary of the current body of knowledge regarding psychological, physiological, and genetic determinants of chronic pain related to precision pain medicine.

METHODS

Following the Scale for the Assessment of Narrative Review Articles (SANRA) criteria, we employed PubMed/Medline to identify relevant articles using primary database search terms to query articles such as: precision medicine, non-modifiable factors, pain, anesthesiology, quantitative sensory testing, genetics, pain medicine, and psychological.

RESULTS

Precision pain medicine provides an opportunity to identify populations at risk, develop personalized treatment strategies, and reduce side effects and cost through elimination of ineffective treatment strategies. As in other complex chronic health conditions, there are two broad categories that contribute to chronic pain risk: modifiable and non-modifiable patient factors. This review focuses on three primary determinants of health, representing both modifiable and non-modifiable factors, that may contribute to a patient's profile for risk of developing pain and most effective management strategies: psychological, physiological, and genetic factors.

CONCLUSION

Consideration of these three domains is already being integrated into patient care in other specialties, but by understanding the role they play in development and maintenance of chronic pain, we can begin to implement both precision and personalized treatment regimens.

The strength of association between psychological factors and clinical outcome in tendinopathy: A systematic review

Objective

Tendinopathy is often a disabling, and persistent musculoskeletal disorder. Psychological factors appear to play a role in the perpetuation of symptoms and influence recovery in musculoskeletal pain. To date, the impact of psychological factors on clinical outcome in tendinopathy remains unclear. Therefore, the purpose of this systematic review was to investigate the strength of association between psychological factors and clinical outcome in tendinopathy.

Methods

A systematic review of the literature and qualitative synthesis of published trials was conducted. Electronic searches of ovid MEDLINE, ovid EMBASE, PsychINFO, CINAHL and Cochrane Library was undertaken from their inception to June 2020. Eligibility criteria included RCT’s and studies of observational design incorporating measurements of psychological factors and pain, disability and physical functional outcomes in people with tendinopathy. Risk of Bias was assessed by two authors using a modified version of the Newcastle Ottawa Scale. High or low certainty evidence was examined using the GRADE criteria.

Results

Ten studies of observational design (6-cross sectional and 4 prospective studies), involving a sample of 719 participants with tendinopathy were included. Risk of bias for the included studies ranged from 12/21 to 21/21. Cross-sectional studies of low to very low level of certainty evidence revealed significant weak to moderate strength of association (r = 0.24 to 0.53) between psychological factors and clinical outcomes. Prospective baseline data of very low certainty evidence showed weak strength of association between psychological factors and clinical outcome. However, prospective studies were inconsistent in showing a predictive relationship between baseline psychological factors on long-term outcome. Cross sectional studies report similar strengths of association between psychological factors and clinical outcomes in tendinopathy to those found in other musculoskeletal conditions.

Conclusion

The overall body of the evidence after applying the GRADE criteria was low to very low certainty evidence, due to risk of bias, imprecision and indirectness found across included studies. Future, high quality longitudinal cohort studies are required to investigate the predictive value of baseline psychological factors on long-term clinical outcome.