Machine Learning Based Linking of Patient Reported Outcome Measures to WHO International Classification of Functioning, Disability, and Health Activity/Participation Categories.

BACKGROUND: In the primary and secondary medical health sector, patient reported outcome measures (PROMs) are widely used to assess a patient's disease-related functional health state. However, the World Health Organization (WHO), in its recently adopted resolution on "strengthening rehabilitation in all health systems", encourages that all health sectors, not only the rehabilitation sector, classify a patient's functioning and health state according to the International Classification of Functioning, Disability and Health (ICF). AIM: This research sought to optimize machine learning (ML) methods that fully and automatically link information collected from PROMs in persons with unspecific chronic low back pain (cLBP) to limitations in activities and restrictions in participation that are listed in the WHO core set categories for LBP. The study also aimed to identify the minimal set of PROMs necessary for linking without compromising performance. METHODS: A total of 806 patients with cLBP completed a comprehensive set of validated PROMs and were interviewed by clinical psychologists who assessed patients' performance in activity limitations and restrictions in participation according to the ICF brief core set for low back pain (LBP). The information collected was then utilized to further develop random forest (RF) methods that classified the presence or absence of a problem within each of the activity participation ICF categories of the ICF core set for LBP. Further analyses identified those PROM items relevant to the linking process and validated the respective linking performance that utilized a minimal subset of items. RESULTS: Compared to a recently developed ML linking method, receiver operating characteristic curve (ROC-AUC) values for the novel RF methods showed overall improved performance, with AUC values ranging from 0.73 for the ICF category d850 to 0.81 for the ICF category d540. Variable importance measurements revealed that minimal subsets of either 24 or 15 important PROM variables (out of 80 items included in full set of PROMs) would show similar linking performance. CONCLUSIONS: Findings suggest that our optimized ML based methods more accurately predict the presence or absence of limitations and restrictions listed in ICF core categories for cLBP. In addition, this accurate performance would not suffer if the list of PROM items was reduced to a minimum of 15 out of 80 items assessed.

The Back Muscle Surface Electromyography-Based Fatigue Index: A Digital Biomarker of Human Neuromuscular Aging?

As part of our quest for digital biomarkers of neuromuscular aging, and encouraged by recent findings in healthy volunteers, this study investigated if the instantaneous median frequency (IMDF) derived from back muscle surface electromyographic (SEMG) data monitored during cyclic back extensions could reliably differentiate between younger and older individuals with cLBP. A total of 243 persons with cLBP participated in three experimental sessions: at baseline, one to two days after the first session, and then again approximately six weeks later. During each session, the study participants performed a series of three isometric maximal voluntary contractions (MVC) of back extensors using a dynamometer. These were followed by an isometric back extension at 80% MVC, and-after a break-25 slow cyclic back extensions at 50% MVC. SEMG data were recorded bilaterally at L5 (multifidus), L2 (longissimus dorsi), and L1 (iliocostalis lumborum). Linear mixed-effects models found the IMDF-SEMG time-course changes more rapidly in younger than in older individuals, and more prominently in male participants. The absolute and relative reliabilities of the SEMG time-frequency representations were well compared between older and younger participants. The results indicated an overall good relative reliability, but variable absolute reliability levels. IMDF-SEMG estimates derived from cyclic back extensions proved to be successful in reliably detecting differences in back muscle function in younger vs. older persons with cLBP. These findings encourage further research, with a focus on assessing whether an IMDF-SEMG-based index could be utilized as a tool to achieve the preclinical detection of back muscle aging, and possibly predict the development of back muscle sarcopenia.

Do the WHO-ICF personal factors "age" and "sex" impact limited activity and restricted participation category profiles differently between younger and older women and men in multimodal chronic back pain rehabilitation?

PURPOSE: To investigate if the International Classification of Functioning and Health (ICF) context factors "age" and "sex" would impact the disablement and respective improvement with rehabilitation defined with the ICF core set for chronic low back pain (cLBP). Furthermore, associations between limitations/restrictions and measures of body function or quality of life were of interest. MATERIALS AND METHODS: One thousand five hundred and twelve employed cLBP patients who completed 6 months of outpatient rehabilitation and for whom complete assessments were available before and after rehabilitation. Rehabilitation comprised of progressive resistance training, psychological counseling, and educational sessions. Main outcome measures were the ICF-activity/participation core categories automatically predicted from random forests and utilizing information from the Roland Morris Disability Questionnaire and Pain Disability Index. RESULTS: Generalized linear-mixed models revealed that upon completion of rehabilitation the presence of a limitation within the ICF activity "walking" significantly decreased with significant between-group differences. The category "doing housework" demonstrated gender-specific differences, and both gender- and age-specific differences were observed for work-related participation categories. There were no meaningful associations between ICF limitation/restriction categories and body function measures (point-biserial/Spearman's correlations). CONCLUSIONS: The personal factors "age" and "sex" impact some ICF limitation/restriction categories in cLBP; appropriately addressing these personal features could further improve phase III rehabilitation outcome.Implications for rehabilitationConsistent with calls to explore the age and sex/gender influence on health and disease, little is known how these factors affect the disablement of individuals with chronic back pain.The factors "age" and "sex" drive differences in some categories within the ICF activity/restriction categories.If age- and gender-specific features in activities and participation are not appropriately addressed through interventions, rehabilitation outcome may remain suboptimal in cLBP.

Reproducibility of the 6-minute walk test in lung transplant recipients.

PURPOSE: There is reason to believe that the favorable measurement properties of the 6­minute walk test (6MWT) reported for retest reliability and its capability to detect a true change in healthy individuals or persons with chronic respiratory disease may not apply to lung transplant recipients (LuTXr). We therefore investigated retest reliability of the 6MWT and, in addition, made an attempt to explore whether the 6MWT was sensitive enough to detect important changes that occur with postacute rehabilitation in LuTXr after first time LuTX. METHODS: Immediately before postacute rehabilitation, 50 LuTXr completed 6MWT testing twice, separated by 1-2 workdays (retest reliability), and were reassessed after completion of rehabilitation 2 months later (sensitivity to changes). Body function measures and health-related quality of life (HRQoL) assessments were collected at baseline. RESULTS: Baseline retest 6­minute walk distance (6MWD) and the age-related predicted walking distance (6MWD%pred) scores significantly increased before postacute rehabilitation. The intraclass coefficient of correlation ICC of the 6MWD was 0.93 (95% confidence interval, CI: 0.88-0.96) and its smallest real difference (SRD) 79 m (95% CI: 52;107). Receiver operating curve analyses revealed the rehabilitation associated changes in 6MWD/6MWD%pred to exceed the SRD/SRD% values in a highly accurate way. CONCLUSION: The 6MWT overall represents a reliable functional performance tool in LuTXr that is sensitive to detect changes in physical performance as a result of medical postacute rehabilitation.

Perceived psychosocial stressors and coping resources in chronic low back pain patients as classified by the avoidance-endurance model.

Objectives: The Avoidance-Endurance Model distinguishes between subgroups of low back pain (LBP) patients with three maladaptive styles of coping with pain: fear-avoidance (FAR), distress-endurance (DER), eustress-endurance (EER), and one adaptive coping style (AR). This study aimed to compare the quantity of patients' perceived psychosocial stressors and coping resources across these subgroups. Materials and methods: This cross-sectional study was conducted at an outpatient rehabilitation center for patients with chronic musculoskeletal pain. One hundred and thirty-seven patients (69 women/68 men) with chronic LBP were assessed using the following: a demographic checklist, the visual analogue scale, Avoidance-Endurance Questionnaire, Roland-Morris Disability Questionnaire, Pain Disability Index, and 36-Item Short Form. Subsequently, patients participated in semi-structured interviews led by clinical psychologists, which were intended to identify their perception of stressors and coping resources. The quantity of psychosocial stressors and coping resources were analyzed using deductive and inductive content analyses and then compared between subgroups using chi-square-tests. Results: FARs experienced significantly higher levels of "mental suffering" (p = <0.001) and "other workplace problems" compared to ARs and EERs (p = <0.001). DERs reported significantly higher levels of "mental suffering" (p = <0.001), "job stress" (p = 0.022), and "familial losses" (p = 0.029) compared to ARs, whereas the AR group demonstrated significantly more "coping resources" (p = 0.001) compared to FARs. Conclusion: AEM-subgroups differed in the quantity of perceived psychosocial stressors and coping resources with AR, who demonstrated a lower risk for pain chronicity and reported the highest quantity of resources. The variability across subgroups may imply differences in patients needs regarding therapeutic interventions and suggests that a resource-centered approach to cope with stress and pain may be beneficial.

Changes in the International Classification of Functioning, Disability, and Health Components "Activity/Participation" as Predicted Through Patient-Reported Outcomes Along With Comprehensive Back Pain Rehabilitation.

OBJECTIVES: The World Health Organization (WHO) recommended the International Classification of Functioning, Disability and Health (ICF) but its use in clinical practice is sparse. This study investigated the limitations and restrictions in the most relevant brief ICF core set categories for chronic low back pain (cLBP) as automatically predicted from routinely measured outcomes using a novel, validated mapping algorithm. MATERIALS AND METHODS: Of 2718 cLBP patients recruited, data from 1541 (64% females) were available from before and at the end of 6 months comprehensive outpatient rehabilitation. Assessments included the Roland Morris Disability Questionnaire (RMDQ) and Pain Disability Index (PDI) questionnaires, the percentage of patients with predicted limitations and restrictions in important activity and participation ICF categories, bodily functional measurements, pain intensity, and anxiety/depression (EQ-5D). RESULTS: At baseline, both the RMDQ and the PDI measures were within the third of the lowest disability scores whilst 80% of the patients had limitations with "maintaining a body position" and 30% with "walking" ICF categories. Intervention-associated gains in the maximum isometric lumbar extension and flexion strength and the lumbar range of motion were significant overall, but improvements in patients' ICF limitations/restrictions varied. Anxiety/depression, lumbar range of motion, and extension strength all had a significant impact on the majority of the ICF categories, whereas flexion strength had none. DISCUSSION: The rate of patients with predicted limitations/restrictions in activity/participation ICF core categories for cLBP partly mirrored disability levels and the impact of the body function scores on these limitations/restrictions in ICF categories was varied. Thus, assessing problems in the ICF activity/participation core categories is of relevance to clinical practice for both treatment goal setting and intervention planning. This may be achieved by computer-generated mapping without additional time burden.

In-depth analysis of life values and their corresponding inhibitors and facilitators in chronic low back pain patients: A mixed-method approach.

BACKGROUND: The struggle with pain often interferes with the ability of chronic low back pain (CLBP) patients to pursue important life values due to psychological inflexibility. OBJECTIVE: This research examined life values, related inhibitors and facilitators relevant to personalized therapy planning. METHODS: Two hundred and forty-four CLBP patients completed the Chronic Pain Values Inventory (CPVI). Of these, 68 patients were interviewed to assess inhibitors and facilitators related to life values. Mixed-effects models quantitatively examined differences in the values, structuring content analysis served to qualitatively analyze the interviews. RESULTS: Participants rated the value "family" as being of highest importance and success. The largest discrepancy between importance and success was found for "health". Content analyses revealed a broad range of inhibitors and facilitators related to the examined life values with the highest number of inhibitors related to "work". Facilitators were also found to be of relevance to all life values, but to a lower extent than inhibitors. CONCLUSIONS: The perceived importance and success of life values and their related inhibitors and facilitators may differentially affect CLBP patients. Considering such individual aspects is therefore of utmost importance to improve patient care, as they enable treatment goals and the therapeutic strategies to be adapted accordingly.

Mapping patient reported outcome measures for low back pain to the International Classification of Functioning, Disability and Health using random forests.

BACKGROUND: There is need for feasible and efficient concepts to document patients functioning impairment according to the International Classification of Functioning, Disability and Health (ICF) without imposing additional burden to clinical practice. AIM: The aim of this study was to develop and validate an automatic linking approach that translates information derived from patient reported outcome measures (PROMs) into the ICF. DESIGN: Proof-of-concept study. SETTING: Participants completed both the Roland-Morris disability questionnaire and the Pain Disability Index and were interviewed using the activity and participation component of the ICF brief core set for low back pain. POPULATION: A total of 244 patients with light to moderate chronic low back pain (cLBP); additionally, 19 patients with higher levels of pain were recruited and assessed for validation purposes. METHODS: Based on information extracted from the PROMs and considering the factors age and gender, random forest models that predicted the presence or absence of an impairment at the specific ICF category were computed and validated. RESULTS: Accuracy of the models was found to be acceptable for the most relevant ICF brief core set categories for low back pain if applied at the population level. CONCLUSIONS: The presented approach can be assumed valid if applied at large on population level. The results are of relevance for the further development of automatic linking programs that would allow the ICF-based classification of functioning properties within the International Classification of Diseases (ICD-11) for any health condition. CLINICAL REHABILITATION IMPACT: The presented approach eases the documentation of patients' functioning impairment according to the standardized ICF.

Correction to: Age- and sex-specific effects in paravertebral surface electromyographic back extensor muscle fatigue in chronic low back pain.

Unfortunately, the author names in the author group section were incorrectly captured in the published online paper.

Psychological Subgrouping to Assess the Risk for the Development or Maintenance of Chronic Musculoskeletal Pain: Is This the Way Forward?

BACKGROUND: Because musculoskeletal pain problems are so prevalent, new methods of evaluating and treating patients are needed to increase effectiveness. Subgrouping is a method wherein patients are classified into defined groups on the basis of psychosocial factors with the expectation of more specific and tailored treatments can be prescribed for them. For those seeking care for a new episode, the risk of developing chronic pain-related disability is assessed, whereas, for those with existing pain, the risk for the maintenance of the chronic pain problem is evaluated. AIM: The purpose of this narrative review is to examine how patients are classified into subgroups with regard to methods of evaluation and to ascertain whether subgrouping actually facilitates treatment. RESULTS: For the development of disability, screening tools, for example, the Örebro Musculoskeletal Pain Screening Questionnaire, accurately stratify patients into groups (eg, high, medium, low risk) that predict future pain-related work disability. In addition, several studies show that treatments that directly key in on risk groups enjoy enhanced outcomes compared with treatment as usual. For the maintenance of chronic musculoskeletal pain problems, there are several instruments that classify patients into specific groups or profiles, for example, on the basis of the avoidance and endurance model or the International Classification of Functioning, Disability and Health (ICF) assessment. Although some evidence shows that these classifications are related to treatment outcome, we found no study that directly tested a system for providing treatment matched to the subgrouping for maintenance. CONCLUSIONS: We conclude that it is possible to reliably subgroup patients with musculoskeletal problems. Likewise, treatments that address the risk factors in the screening procedure may enhance outcomes compared with treatment as usual. More work is needed, however, to better understand the mechanism, so that assessment methods can be improved, and treatment specific to subgroups can be developed and evaluated.