Modifiable prognostic factors of high societal costs among people on sick leave due to musculoskeletal disorders: findings from an occupational cohort study.

OBJECTIVES: The objective was to identify modifiable prognostic factors of high societal costs among people on sick leave due to musculoskeletal disorders, and to identify modifiable prognostic factors of high costs related to separately healthcare utilisation and productivity loss. DESIGN: A prospective cohort study with a 1-year follow-up. PARTICIPANTS AND SETTING: A total of 549 participants (aged 18-67 years) on sick leave (≥ 4 weeks) due to musculoskeletal disorders in Norway were included. OUTCOME MEASURES AND METHOD: The primary outcome was societal costs aggregated for 1 year of follow-up and dichotomised as high or low, defined by the top 25th percentile. Secondary outcomes were high costs related to separately healthcare utilisation and productivity loss aggregated for 1 year of follow-up. Healthcare utilisation was collected from public records and included primary, secondary and tertiary healthcare use. Productivity loss was collected from public records and included absenteeism, work assessment allowance and disability pension. Nine modifiable prognostic factors were selected based on previous literature. Univariable and multivariable binary logistic regression analyses were performed to identify associations (crude and adjusted for selected covariates) between each modifiable prognostic factor and having high costs. RESULTS: Adjusted for selected covariates, six modifiable prognostic factors associated with high societal costs were identified: pain severity, disability, self-perceived health, sleep quality, return to work expectation and long-lasting disorder expectation. Depressive symptoms, work satisfaction and health literacy showed no prognostic value. More or less similar results were observed when high costs were related to separately healthcare utilisation and productivity loss. CONCLUSION: Factors identified in this study are potential target areas for interventions which could reduce high societal costs among people on sick leave due to musculoskeletal disorders. However, future research aimed at replicating these findings is warranted. TRIAL REGISTRATION NUMBER: NCT04196634, 12 December 2019.

Identifying latent subgroups in the older population seeking primary health care for a new episode of back pain - findings from the BACE-N cohort.

BACKGROUND: Back pain is the number one condition contributing to years lived with disability worldwide, and one of the most common reasons for seeking primary care. Research on this condition in the ageing population is sparse. Further, the heterogeneity of patients with back pain complicates the management in clinical care. It is possible that subgrouping people with similar characteristics would improve management. This paper aimed to identify latent classes based on demographics, pain characteristics, psychosocial behavior, and beliefs and attitudes about back pain, among older patients seeking primary care with a new episode of back pain, and to examine if there were differences regarding the classes' first point-of-contact. METHODS: The study was part of the international BACE (Back complaints in elders) consortium and included 435 patients aged ≥ 55 years seeking primary care (general practitioners, physiotherapists, and chiropractors) in Norway from April 2015 to March 2020. A latent class analysis was performed to identify latent classes. The classes were described in terms of baseline characteristics and first point-of-contact in primary care. RESULTS: Four latent classes were identified. The mean age was similar across groups, as were high expectations towards improvement. Class 1 (n = 169, 39%), the "positive" class, had more positive attitudes and beliefs, less pain catastrophizing and shorter duration of current pain episode. Class 2 (n = 31, 7%), the "fearful" class, exhibited the most fear avoidance behavior, and had higher mean pain intensity. Class 3 (n = 33, 8%), the "distressed" class, had the highest scores on depression, disability, and catastrophizing. Finally, class 4 (n = 202, 46%), the "hopeful" class, showed the highest expectations for recovery, although having high pain intensity. The identified four classes showed high internal homogeneity, sufficient between-group heterogeneity and were considered clinically meaningful. The distribution of first point-of-contact was similar across classes, except for the positive class where significantly more patients visited chiropractors compared to general practitioners and physiotherapists. CONCLUSIONS: The identified classes may contribute to targeting clinical management of these patients. Longitudinal research on these latent classes is needed to explore whether the latent classes have prognostic value. Validation studies are needed to evaluate external validity. TRIAL REGISTRATION: Clinicaltrials.gov NCT04261309.

External validation and updating of prognostic prediction models for nonrecovery among older adults seeking primary care for back pain.

ABSTRACT: Prognostic prediction models for 3 different definitions of nonrecovery were developed in the Back Complaints in the Elders study in the Netherlands. The models' performance was good (optimism-adjusted area under receiver operating characteristics [AUC] curve ≥0.77, R2 ≥0.3). This study aimed to assess the external validity of the 3 prognostic prediction models in the Norwegian Back Complaints in the Elders study. We conducted a prospective cohort study, including 452 patients aged ≥55 years, seeking primary care for a new episode of back pain. Nonrecovery was defined for 2 outcomes, combining 6- and 12-month follow-up data: Persistent back pain (≥3/10 on numeric rating scale) and persistent disability (≥4/24 on Roland-Morris Disability Questionnaire). We could not assess the third model (self-reported nonrecovery) because of substantial missing data (>50%). The models consisted of biopsychosocial prognostic factors. First, we assessed Nagelkerke R2 , discrimination (AUC) and calibration (calibration-in-the-large [CITL], slope, and calibration plot). Step 2 was to recalibrate the models based on CITL and slope. Step 3 was to reestimate the model coefficients and assess if this improved performance. The back pain model demonstrated acceptable discrimination (AUC 0.74, 95% confidence interval: 0.69-0.79), and R2 was 0.23. The disability model demonstrated excellent discrimination (AUC 0.81, 95% confidence interval: 0.76-0.85), and R2 was 0.35. Both models had poor calibration (CITL <0, slope <1). Recalibration yielded acceptable calibration for both models, according to the calibration plots. Step 3 did not improve performance substantially. The recalibrated models may need further external validation, and the models' clinical impact should be assessed.

The one-year clinical course of back-related disability and the prognostic value of comorbidity among older adults with back pain in primary care.

ABSTRACT: Back pain and comorbidity are common in older adults. Comorbidity is a promising prognostic factor for the clinical course of back-related disability, but confirmatory studies assessing its prognostic value are needed. Thus, the aims of this study were to describe the clinical course of back-related disability during 1-year follow-up in patients aged ≥55 years visiting primary care (general practitioner, physiotherapist, or chiropractor) with a new episode of back pain and assess the prognostic value of comorbidity on back-related disability during 1-year follow-up. A prospective cohort study was conducted, including 452 patients. The outcome measure was Roland-Morris Disability Questionnaire (RMDQ, range 0-24) measured at baseline and at 3-, 6-, and 12-month follow-up. The Self-Administered Comorbidity Questionnaire was used to assess comorbidity count (CC, range 0-15) and comorbidity burden (CB, range 0-45). The RMDQ scores improved from median (interquartile range) 9 (4-13) at baseline to 4 (1-9), 4 (0-9), and 3 (0-9) at 3, 6, and 12 months, respectively. Using linear mixed-effects models, we found that CC and CB were independently associated with RMDQ scores. A 1-point increase in CC was associated with an increase in RMDQ score of 0.76 points (95% confidence interval [0.48-1.04]) over the follow-up year, adjusted for known prognostic factors. A 1-point increase in CB was associated with an increased RMDQ score of 0.47 points (95% confidence interval [0.33-0.61]). In conclusion, the clinical course of back-related disability for older adults presenting in primary care was favorable, and increased comorbidity was an independent prognostic factor for increased disability levels.

Healthcare utilization and related costs among older people seeking primary care due to back pain: findings from the BACE-N cohort study.

OBJECTIVES: To describe healthcare utilization and estimate associated costs during 1 year of follow-up among older people seeking primary care due to a new episode back pain and to describe healthcare utilization across patients with different risk profiles stratified using the StarT Back Screening Tool (SBST). DESIGN: Prospective cohort study. PARTICIPANTS AND SETTING: A total of 452 people aged ≥55 years seeking Norwegian primary care with a new episode of back pain were included. OUTCOME MEASURES: The primary outcome of this study was total cost of healthcare utilization aggregated for 1 year of follow-up. Secondary outcomes included components of healthcare utilization aggregated for 1 year of follow-up. Healthcare utilization was self-reported and included: primary care consultations, medications, examinations, hospitalisation, rehabilitation stay, and operations. Costs were estimated based on unit costs collected from national pricelists. Healthcare utilization across patients with different SBST risk profiles was compared using Kruskal-Wallis test, post hoc Mann-Whitney U tests and Bonferroni adjustment. RESULTS: In total, 438 patients were included in the analysis. Mean (BCa 95% CI) total cost per patient over 1 year was €825 (682-976). Median (BCa 95% CI) total cost was €364 (307-440). The largest cost category was primary care consultations, accounting for 56% of total costs. Imaging rate was 34%. The most commonly used medication was paracetamol (27%-35% of patients). Medium- and high-risk patients had a significantly higher degree of healthcare utilization compared with low-risk patients (p<0.030). CONCLUSION: This study estimated a 1 year mean and median cost of healthcare utilization of €825 and €364, respectively. Patients within the top 25th percentile accounted for 77% of all costs. Patients classified as medium risk and high risk had a significantly higher degree of healthcare utilization compared with patients classified as low risk. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT04261309, results.

Modifiable prognostic factors of high costs related to healthcare utilization among older people seeking primary care due to back pain: an identification and replication study.

BACKGROUND: Back pain is an extensive burden to our healthcare system, yet few studies have explored modifiable prognostic factors associated with high costs related to healthcare utilization, especially among older back pain patients. The aims of this study were to identify modifiable prognostic factors for high costs related to healthcare utilization among older people seeking primary care with a new episode of back pain; and to replicate the identified associations in a similar cohort, in a different country. METHODS: Data from two cohort studies within the BACE consortium were used, including 452 and 675 people aged ≥55 years seeking primary care with a new episode of back pain. High costs were defined as costs in the top 25th percentile. Healthcare utilization was self-reported, aggregated for one-year of follow-up and included: primary care consultations, medications, examinations, hospitalization, rehabilitation stay and operations. Costs were estimated based on unit costs collected from national pricelists. Nine potential modifiable prognostic factors were selected based on previous literature. Univariable and multivariable binary logistic regression models were used to identify and replicate associations (crude and adjusted for selected covariates) between each modifiable prognostic factor and high costs related to healthcare utilization. RESULTS: Four modifiable prognostic factors associated with high costs related to healthcare utilization were identified and replicated: a higher degree of pain severity, disability, depression, and a lower degree of physical health-related quality of life. Kinesiophobia and recovery expectations showed no prognostic value. There were inconsistent results across the two cohorts with regards to comorbidity, radiating pain below the knee and mental health-related quality of life. CONCLUSION: The factors identified in this study may be future targets for intervention with the potential to reduce high costs related to healthcare utilization among older back pain patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT04261309, 07 February 2020. Retrospectively registered.

Assessing physical workload among people with musculoskeletal disorders: validity and reliability of the physical workload questionnaire.

BACKGROUND: Demands of physical work are related to musculoskeletal disorders, and hence, important to assess. The Physical Workload Questionnaire (PWQ) is based on 26 items related to physical workload. The PWQ has been translated into Norwegian, but its psychometric properties have not yet been tested. The aim of this study was to assess the validity and reliability of the PWQ among patients with musculoskeletal disorders. METHODS: A cross-sectional study with a test-retest design was conducted to assess construct validity (structural validity and hypothesis testing) and reliability (internal consistency and test-retest reliability) among employed patients with musculoskeletal disorders. Exploratory factor analysis was performed to assess the structural validity and number of items to be included in the Norwegian version of the PWQ. Hypothesis testing was assessed by 14 a priori hypotheses ("known" group, convergent and discriminant validity). Internal consistency was evaluated using Cronbach's alpha and test-retest reliability by Intraclass Correlation Coefficient (ICC2.1), Standard Error of Measurement (SEMagreement) and Smallest Detectable Change (SDC95%ind). RESULTS: In total, 115 patients with a mean age (SD) of 46 (9) years were included, of which 48 were included in the reliability analyses. Exploratory factor analysis resulted in two subscales: "Heavy physical work" (15 items, range 0-100) and "Long-lasting postures and repetitive movements" (7 items, range 0-100). No floor or ceiling effects were seen in the subscales. Twelve of the 14 (85%) predefined hypotheses were confirmed. The internal consistency with Cronbach's alpha was 0.94 and 0.85 on subscales 1 and 2, respectively. Test-retest reliability analyses demonstrated an ICC2.1 of 0.96 (95% CI 0.88, 0.98) and 0.92 (95% CI 0.81, 0.96), SEM of 6.9 and 10.0 and SDC95%ind of 19.2 and 27.7 of subscales 1 and 2, respectively. CONCLUSIONS: The Norwegian version of the PWQ demonstrated good validity and reliability and can be used to evaluate physical workload in patients with musculoskeletal disorders.

Clinical Utility of the 6-Item CTS, Boston-CTS, and Hand-Diagram for Carpal Tunnel Syndrome.

Background: Self-reported measures are often used in research and clinical practice to diagnose carpal tunnel syndrome (CTS) and guide therapeutic choices. We aimed to assess the clinical utility of the Norwegian versions of two self-reported outcome measures for symptom severity assessment, the 6-item CTS (CTS-6), and Boston-CTS (BCTQ), and of one diagnostic measure, the hand-diagram, by evaluating measurement properties including discriminative ability for severity assessment (CTS-6, BCTQ), and diagnosis of CTS (hand-diagram). Methods: We performed forward and backward translation and cultural adaptation of the Norwegian CTS-6 and BCTQ. Following COSMIN guidelines, we investigated internal consistency, reliability, construct validity, and discriminative ability for distinguishing between severity levels of CTS in patients with confirmed CTS for the CTS-6 and BCTQ and reliability and discriminative ability for diagnosing CTS for the hand-diagram. Results: Two hundred and fifty-one patients referred for diagnostic work-up for CTS with nerve conduction studies (NCS) participated. The CTS-6 and BCTQ had acceptable internal consistency (Crohnbach's α = 0.82 and 0.86, respectively), reliability (ICC = 0.86 and 0.90; SEM = 0.24 and 0.20; SDC95% = 0.68 and 0.55, respectively), construct validity (all eight pre-defined hypotheses confirmed) and discriminative ability to distinguish between severity levels of CTS [Area under the curve (AUC) = 0.75, 95% CI 0.64-0.85]. The hand-diagram had acceptable reliability (Cohen's kappa = 0.69) and discriminative ability to diagnose CTS (sensitivity = 0.72, specificity = 0.90). Conclusion: Our findings support the clinical utility of the CTS-6 and BCTQ for symptom severity assessment and of the hand-diagram for diagnostic screening.