Evaluating Effectiveness of Telerehabilitation Services Among Injured Workers Treated in a Canadian Workers' Compensation System: A Population-Based Study.

PURPOSE: To evaluate the effectiveness of telerehabilitation for promoting return-to-work (RTW) among injured workers. METHODS: We conducted a pragmatic, quasi-experimental study comparing telerehabilitation, in-person, or hybrid services. Descriptive statistics analyzed demographics, occupational factors, and patient-reported outcome measures (PROMs). Kruskal-Wallis tests investigated differences between mode of delivery and changes in PROM scores. Logistic and Cox-proportional hazard regression examined associations between mode of delivery and RTW status or days receiving wage replacement benefits in the first-year post-discharge, respectively, while controlling for potential confounders. RESULTS: A slightly higher percentage of the 3,708 worker sample were male (52.8%). Mean (standard deviation (SD)) age across all delivery formats was 45.5 (12.5) years. Edmonton zone had the highest amount of telerehabilitation delivery (53.5%). The majority of workers had their program delivered in a hybrid format (54.1%) and returned to work (74.4%) at discharge. All PROMs showed improvement although differences across delivery formats were not clinically meaningful. Delivery via telerehabilitation had significantly lower odds of RTW at discharge (Odds Ratio: 0.82, 95% Confidence Interval: 0.70-0.97) and a significantly lower risk of experiencing suspension of wage replacement benefits in the first year following discharge (Hazard Ratio: 0.92, 95% Confidence Interval: 0.84-0.99). Associations were no longer significant when confounders were controlled for. CONCLUSION: RTW outcomes were not statistically different across delivery formats, suggesting that telerehabilitation is a novel strategy that may improve equitable access and earlier engagement in occupational rehabilitation. Factors such as gender and geographic location should be considered when deciding on service delivery format.

Return-to-Work Following Occupational Rehabilitation for Long COVID: Descriptive Cohort Study.

BACKGROUND: Emerging evidence suggests that worldwide, between 30% and 50% of those who are infected with COVID-19 experience long COVID (LC) symptoms. These symptoms create challenges with return-to-work (RTW) in a high proportion of individuals with LC. To tailor rehabilitation programs to LC sequelae and help improve RTW outcomes, more research on LC rehabilitation program outcomes is needed. OBJECTIVE: This study describes the characteristics and outcomes of workers who participated in an LC occupational rehabilitation program. METHODS: A cohort study was conducted. Descriptive variables included demographic and occupational factors as well as patient-reported outcome measures (PROMs, ie, the Fatigue Severity Scale [FSS], the Post-COVID Functional Scale [PCFS], the 36-item Short Form Health Survey [SF-36], the Pain Disability Index [PDI], the pain Visual Analogue Scale [VAS], the 9-item Patient Health Questionnaire [PHQ-9], the 7-item Generalized Anxiety Disorder Questionnaire [GAD-7], and the Diagnostic and Statistical Manual for Mental Disorders Fifth Edition [DSM-5] posttraumatic stress disorder [PTSD] checklist [PCL-5]). The main outcome variable was the RTW status at discharge. Descriptive statistics were calculated. Logistic regression examined predictors of RTW. RESULTS: The sample consisted of 81 workers. Most workers were female (n=52, 64%) and from health-related occupations (n=43, 53%). Only 43 (53%) individuals returned to work at program discharge, with 40 (93%) of these returning to modified duties. Although there were statistically significant improvements on the pain VAS (mean 11.1, SD 25.6, t31=2.5, P=.02), the PDI (mean 9.4, SD 12.5, t32=4.3, P<.001), the FSS (mean 3.9, SD 8.7, t38=2.8, P=.01), the SF-36 PCS (mean 4.8, SD 8.7, t38=-3.5, P=.001), the PHQ-9 (mean 3.7, SD 4.0, t31=5.2, P<.001), and the GAD-7 (mean 1.8, SD 4.4, t22=1.8, P=.03), there were no significant improvements in the PCFS, the overall mental component score (MCS) of the SF-36, or on the PCL-5. The availability of modified duties (odds ratio [OR] 3.38, 95% CI 1.26-9.10) and shorter time between infection and admission for rehabilitation (OR 0.99, 95% CI 0.99-1.00) predicted RTW even when controlling for age and gender. CONCLUSIONS: Workers undergoing LC rehabilitation reported significant but modest improvements on a variety of PROMs, but only 43 (53%) returned to work. Outcomes would likely improve with increased availability of modified duties and timelier rehabilitation. Additional research is needed, including larger observational cohorts as well as randomized controlled trials to evaluate the effectiveness of LC rehabilitation.

A Descriptive Study of the Implementation of Remote Occupational Rehabilitation Services Due to the COVID-19 Pandemic Within a Workers' Compensation Context.

Purpose The Coronavirus Disease (COVID-19) pandemic resulted in dramatic changes to avoid virus spread. In Canada, following provincial legislation the Workers' Compensation Board of Alberta (WCB-Alberta) stopped in-person rehabilitation services on March 23, 2020. On April 1, training began on remote service delivery using videoconferencing or telerehabilitation, which started April 3. We studied WCB-Alberta's transition to remote rehabilitation service delivery. Methods A population-based descriptive study was conducted, with data extracted from the WCB-Alberta database. This included clinical data from rehabilitation providers. We included workers completing services between January 1 and May 31, 2020. We statistically examined differences before and after the transition to remote services. Results The dataset included 4,516 individuals with work-related injuries. The mean number of work assessments per week pre-COVID was 244.6 (SD 83.5), which reduced to 135.9 (SD 74.5). Workers undergoing remote assessments were significantly more likely to work in health care or trades, did not require an interpreter, and were less likely to be working or judged as ready to return to work. Number of completed rehabilitation programs also reduced from 125.6 to 40.8 per week, with most (67.1%) remote programs being functional restoration. Few adverse effects were observed. Conclusions We describe the transition to completely remote delivery of occupational rehabilitation due to COVID-19 physical distancing restrictions in one Canadian compensation jurisdiction. It appears the use of remote services was successful but proceeded cautiously, with fewer complex cases being referred for assessment or rehabilitation. Further research examining longer-term work outcomes and stakeholder perceptions is needed.

Word Memory Test Predicts Recovery in Claimants With Work-Related Head Injury.

OBJECTIVE: To investigate the predictive validity of the Word Memory Test (WMT), a verbal memory neuropsychological test developed as a performance validity measure to assess memory, effort, and performance consistency. DESIGN: Cohort study with 1-year follow-up. SETTING: Workers' compensation rehabilitation facility. PARTICIPANTS: Participants included workers' compensation claimants with work-related head injury (N=188; mean age, 44y; 161 men [85.6%]). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Outcome measures for determining predictive validity included days to suspension of wage replacement benefits during the 1-year follow-up and work status at discharge in claimants undergoing rehabilitation. Analysis included multivariable Cox and logistic regression. RESULTS: Better WMT performance was significantly but weakly correlated with younger age (r=-.30), documented brain abnormality (r=.28), and loss of consciousness at the time of injury (r=.25). Claimants with documented brain abnormalities on diagnostic imaging scans performed better (∼9%) on the WMT than those without brain abnormalities. The WMT predicted days receiving benefits (adjusted hazard ratio, 1.13; 95% confidence interval, 1.04-1.24) and work status outcome at program discharge (adjusted odds ratio, 1.62; 95% confidence interval, 1.13-2.34). CONCLUSIONS: Our results provide evidence for the predictive validity of the WMT in workers' compensation claimants. Younger claimants and those with more severe brain injuries performed better on the WMT. It may be that financial incentives or other factors related to the compensation claim affected the performance.

Reference values for the SF-36 in Canadian injured workers undergoing rehabilitation.

PURPOSE: The Medical Outcomes Study 36-item Short Form Survey (SF-36) is a widely used measure of health-related quality of life and normative reference values have been published for the general population of several countries. Since injured workers often experience pain, disability and other health challenges, we evaluated SF-36 reference values for Canadian workers' compensation claimants undergoing rehabilitation. METHODS: Descriptive cross-sectional design. Data were gathered as part of a study aimed at developing a tool for selecting rehabilitation programs. Data were available on a wide variety of measures, including the SF-36. We calculated age- and sex-adjusted reference values, and stratified analyses based on type of rehabilitation, employment status and diagnostic group. RESULTS: Data were available on 5,622 claimants undergoing rehabilitation. Claimants reported significant limitations on all SF-36 scales, but were especially limited on the Role Emotional and Bodily Pain scales (~3 standard deviations below typical Canadian norms). Unemployed, middle-aged claimants undergoing chronic pain programs reported the lowest health status, but SF-36 scores varied minimally across diagnoses. CONCLUSIONS: Claimant scores on the SF-36 were below population norms across all health scales and differed depending on age, employment status and type of rehabilitation. These data will be useful for assessing the health status of injured workers and evaluating the effect of rehabilitation interventions.

Lumbar spinal stenosis is a highly genetic condition partly mediated by disc degeneration.

Objective. Lumbar spinal stenosis is one of the most commonly diagnosed spinal disorders in older adults. Although the pathophysiology of the clinical syndrome is not well understood, a narrow central canal or intervertebral foramen is an essential or defining feature. The aim of the present study was to estimate the magnitude of genetic versus environmental influences on central lumbar spinal stenosis and to investigate disc degeneration and stature or bone development as possible genetic pathways.Methods. A classic twin study with multivariate analyses considering lumbar level and other covariates was conducted. The study sample comprised 598 male twins (147 monozygotic and 152 dizygotic pairs), 35-70 years of age, from the population-based Finnish Twin Cohort. The primary phenotypes were central lumbar stenosis as assessed qualitatively on magnetic resonance imaging (MRI) and quantitatively measured dural sac cross-sectional area. Additional phenotypes (to examine possible genetic pathways) included disc bulging and standing height, as an indicator of overall skeletal size or development.Results. The heritability estimate (h²) for qualitatively assessed central lumbar spinal stenosis on MRI was 66.9% (95% confidence interval [95% CI] 56.8,74.5). The broad-sense heritability estimate for dural sac cross-sectional area was 81.2% (95% CI 74.5, 86.1),with a similar magnitude of genetic influences across lumbar levels (h²=72.4­75.6). The additive genetic correlation of quantitatively assessed stenosis and disc bulging was extremely high. There was no indication of shared genetic influences between stenosis and stature.Conclusion. Central lumbar spinal stenosis and associated dural sac dimensions are highly genetic, and disc degeneration (bulging) appears to be one pathway through which genes influence spinal stenosis.

Are performance-based functional assessments superior to semistructured interviews for enhancing return-to-work outcomes?

OBJECTIVE: To examine whether use of functional capacity evaluation (FCE) leads to better outcomes for injured workers. DESIGN: Cluster randomized controlled trial conducted with analysis at level of claimant. SETTING: Rehabilitation facility. PARTICIPANTS: Participants included claimants (N=203); of these, 103 were tested with FCE. Data were collected on all claimants undergoing RTW assessment at the facility for musculoskeletal conditions. Participants were predominantly employed (59%) men (73%) with chronic musculoskeletal conditions (median duration, 496d). INTERVENTIONS: FCEs are commonly used to identify work abilities and inform return-to-work (RTW) decisions. Therefore, FCE results have important consequences. Clinicians who were trained and experienced in performing FCEs were randomized into 2 groups. One group included 14 clinicians who were trained to conduct a semistructured functional interview; the other group (control group) continued to use standard FCE procedures. MAIN OUTCOME MEASURES: Outcomes included RTW recommendations after assessment, functional work level at time of assessment and 1, 3, and 6 months after assessment, and compensation outcomes. Analysis included Mann-Whitney U, chi-square, and t tests. RESULTS: All outcomes were similar between groups, and no statistically or clinically significant differences were observed. Mean differences between groups on functional work levels at assessment and follow-up ranged from 0.1 to 0.3 out of 4 (3%-8% difference, P>.05). CONCLUSIONS: Performance-based FCEs did not appear to enhance RTW outcomes beyond information gained from semistructured functional interviewing. Use of functional interviewing has the potential to improve efficiency of RTW assessment without compromising clinical, RTW, or compensation outcomes.

A cluster randomized clinical trial comparing functional capacity evaluation and functional interviewing as components of occupational rehabilitation programs.

PURPOSE: Functional capacity evaluations (FCE) are used to identify work abilities and are commonly integrated into rehabilitation programs. We studied whether integrating FCE into rehabilitation leads to better outcomes for injured workers. METHODS: A cluster randomised controlled trial was conducted at a workers' compensation rehabilitation facility (registration ISRCTN61284905). Clinicians were randomised into 2 groups: 1 group used FCE while another conducted semi-structured functional interviews. Outcomes included recommendations following assessment, rehabilitation program outcomes including functional work levels and pain intensity, as well as compensation outcomes at 1, 3, and 6 months after assessment. Analysis included Mann-Whitney U, Chi square and t tests. RESULTS: Subjects included 225 claimants of whom 105 were tested with FCE. Subjects were predominantly employed (84 %) males (63 %) with sub-acute musculoskeletal conditions (median duration 67 days). Claimants undergoing FCE had ~15 % higher average functional work levels recommended at time of assessment (Mann-Whitney U = 4,391.0, p < 0.001) but differences at other follow-up times were smaller (0-8 %), in favour of functional interviewing, and not statistically significant. Clinically important improvement during rehabilitation in functional work level (0.9/4, SRM = 0.94), pain intensity (2.0/10, SRM = 0.88) and self-reported disability (21.8/100, SRM = 1.45) were only observed in those undergoing the functional interview. CONCLUSIONS: Performance-based FCE integrated into occupational rehabilitation appears to lead to higher baseline functional work levels compared to a semi-structured functional interview, but not improved RTW rates or functional work levels at follow-up. Functional interviewing has potential for efficiency gains and higher likelihood of clinically important improvement following rehabilitation, however further research is needed.

Is level- and side-specific multifidus asymmetry a marker for lumbar disc pathology?

BACKGROUND CONTEXT: Several reports suggest that level- and side-specific multifidus atrophy or fat infiltration may be related to localized spinal pathology and symptoms. In particular, a study using a porcine model reported rapid level- and side-specific multifidus atrophy and adipocyte enlargement resulting from anterolateral disc or nerve root lesions. PURPOSE: To investigate asymmetry in cross-sectional area (CSA) and fat infiltration in multifidus and other paraspinal muscles in patients with acute or subacute unilateral symptoms of radiculopathy and concordant posterolateral disc herniation. If multifidus asymmetry is indeed related to local pathology, this may serve as a marker for helping to target the search for less clearly identifiable pathology responsible for low back-related symptoms, which currently remains elusive in approximately 85% of those seeking care. STUDY DESIGN: Cross-sectional observational study. PATIENT SAMPLE: Subjects were patients referred to magnetic resonance imaging (MRI) with unilateral leg symptoms of less than 6 weeks onset suggestive of radiculopathy, with a consistent posterolateral lumbar disc herniation verified on imaging. METHODS: Using T2-weighted axial MRI, measurements were obtained for total muscle CSA and signal intensity, functional (fat-free) CSA, and the ratio of functional CSA to total CSA. RESULTS: Forty-three subjects met the inclusion criteria. The ratio of functional CSA to total muscle CSA was smaller on the side of the herniation than on the unaffected side, both below (mean 0.69 vs. 0.72, p=.007) and at the level of herniation (mean 0.78 vs. 0.80, p=.031). Multifidus signal intensity (fat infiltration) was greater on the side of the herniation at the level below the herniation (p=.014). Contrary to expectation, greater total multifidus CSA was found ipsilateral to the pathology at the level of herniation (p=.033). No asymmetries were found at the level above the herniation or in any other paraspinal muscles, with the exception of higher signal in the erector spinae at the level and side of herniation. CONCLUSIONS: Multifidus may be particularly responsive to, or indicative of, localized lumbar disc or nerve root pathology within the first 6 weeks of symptoms as expressed through fat infiltration, but not through CSA asymmetry on MRI. However, such measurements are not reliable markers of lumbar pathology on an individual basis for use in clinical or research settings.

What is the rate of functional improvement during occupational rehabilitation in workers' compensation claimants?

OBJECTIVES: We examined the rate of functional change (using performance measures and a self-report questionnaire) during interdisciplinary occupational rehabilitation in workers' compensation claimants with a variety of musculoskeletal conditions. We also estimated the rate of improvement that could be considered clinically important and examined factors associated with rate of functional improvement. METHODS: A prospective cohort design was used, with data collected before and after claimants participated in an interdisciplinary occupational rehabilitation program. A consecutive sample was formed of claimants admitted between July 2005 and June 2007. Measures included performance-based functional measures (functional capacity evaluation, FCE) and a self-report questionnaire (pain disability index, PDI). RESULTS: The sample included 582 compensation claimants with a variety of musculoskeletal conditions. The majority of claimants experienced functional improvement during rehabilitation. Claimants with the outcome status 'Return-to-Work Pre-accident' had the highest rate of functional change (up to 5 kg/week on floor to waist lifting, ~7 points/week on the PDI). CONCLUSION: The clinically important rate of functional change appears to be 5 kg/week on FCE floor-to-waist lifting and 7 points/week on the PDI (scored out of 100). Rate of functional change appears to be multifactorial, with a variety of physical, demographic, clinical, and environmental factors explaining rate of change.

Visual and quantitative assessment of lateral lumbar spinal canal stenosis with magnetic resonance imaging.

BACKGROUND: Lateral lumbar spinal canal stenosis is a common etiology of lumbar radicular symptoms. Quantitative measurements have commonly demonstrated better repeatability than visual assessments. We are not aware of any studies examining the repeatability of quantitative assessment of the lateral canal. PURPOSE: To evaluate the repeatability of visual assessments and newly developed quantitative measurements of lateral lumbar spinal canal stenosis using magnetic resonance imaging (MRI). MATERIAL AND METHODS: Twenty-eight patients with lateral lumbar spinal canal stenosis or prior spinal surgery with recurrent symptoms were imaged with MRI. A radiologist, a neurosurgeon and a spine research trainee graded visually and quantitatively subarticular (n = 188) and foraminal zones (n = 260) of the lateral spinal canal. Quantitative measurements included the minimal subarticular width and the cross-sectional area of the foramen. RESULTS: The repeatability of visual assessment at the subarticular zone and foraminal zones between raters varied from 0.45-0.59 and 0.42-0.53, respectively. Similarly, the intraclass correlation coefficients for the quantitative measurements varied from 0.67-0.71 and 0.66-0.76, respectively. The intra-rater repeatability for the visual assessments of the subarticular and foraminal zones was 0.70 and 0.62, respectively, while the corresponding intraclass correlation coefficients for quantitative measurements were 0.83 and 0.81, respectively. CONCLUSION: Inter-rater repeatability of visual assessments of lateral stenosis is moderate, whereas quantitative measurements of both subarticular width and the cross-sectional area of the foramen have substantial reproducibility and may be particularly useful for longitudinal studies and research purposes. The clinical value of these parameters requires further study.

Substantial asymmetry in paraspinal muscle cross-sectional area in healthy adults questions its value as a marker of low back pain and pathology.

STUDY DESIGN: A cross-sectional population-based study of paraspinal muscle asymmetry. OBJECTIVE: To examine level- and side-to-side differences in paraspinal muscle areas on magnetic resonance images in a population-based sample of middle aged men without low back pain (LBP). SUMMARY OF BACKGROUND DATA: Level- and side-specific multifidus muscle atrophy and fat infiltration have been suggested as possible markers for localized spinal pathology and LBP, but prior studies have limited generalizability due to small sample sizes, young age of samples and measurement issues. METHODS: From a general population sample of 600 twin men, those reporting no LBP during the prior year, no previous spinal fractures, and no bed rest for at least 1 week in the last 12 months were included in the study. All subjects had T2-weighted axial images available for the three lowest lumbar levels. Both total and fat-free cross-sectional areas (CSAs) of the multifidus and erector spinae muscles at the mid-disc level were measured. Intrarater reliability ranged between 0.90 and 0.98 for area measurements and 0.86 and 0.92 for measurements of side-to-side differences. Data were analyzed using descriptive statistics and paired t tests. RESULTS: Subjects consisted of 126 men whose mean multifidus total CSA measurements varied between 7.3 and 11.1 cm and between 6.9 and 10.8 cm for right and left sides, respectively, depending on the level. The corresponding mean areas for erector spinae were 9.4 to 19.6 cm2 for right side and 10.4 to 19.7 cm2 for left side. The multifidus was larger on the right side than on the left side in 65% to 68% of subjects, depending on spinal level (P < 0.001). The mean asymmetry at the three lowest lumbar levels was 10% to 13.2% and was smallest at L4-L5. Multifidus side-to-side asymmetry ranged from 0.1% to 44.3%. For erector spinae, the left-side measurements tended to be larger, reaching statistical significance (P < 0.0001) for the two lowest levels. The mean side-to-side asymmetry increased caudally for erector spinae, from 8.2% to 18.8% and was significantly different between adjacent levels (P < 0.01). The amount of intramuscular fat significantly increased caudally for both muscles. CONCLUSION: Paraspinal muscle asymmetry greater than 10% was commonly found in men without a history of LBP. This suggests caution in using level- and side-specific paraspinal muscle asymmetry to identify subjects with LBP and spinal pathology.

Quantitative measures of modic changes in lumbar spine magnetic resonance imaging: intra- and inter-rater reliability.

STUDY DESIGN: A measurement reliability study. OBJECTIVE: To develop quantitative measures for Modic changes (MCs) on magnetic resonance (MR) images and evaluate measurement reliability. SUMMARY OF BACKGROUND DATA: MCs have been studied for more than 20 years but the clinical significance remains controversial. Little effort has been made to improve the measurement of MCs. METHODS: The study was approved by the responsible institutional review board. On the basis of Modic classification, a series of quantitative dimension and signal intensity measures were developed for assessing MCs. Midsagittal T1- and T2-weighted MR images from 83 lumbar spines were then qualitatively and quantitatively assessed by two observers independently. Kappa and intraclass correlation coefficient (ICC) were used to examine intra- and inter-rater reliability. Pearson correlation coefficient was used to assess the relationships between the quantitative measurements of MCs. Mean absolute deviation (MAD) and Bland-Altman plots also were used to evaluate measurement errors and limits of agreement for selected measures. RESULTS: For Modic classification, intrarater agreement was excellent (κ = 0.88) and inter-rater agreement was substantial (κ = 0.79). Intrarater agreement also was excellent when obtaining dimension measurements (ICC = 0.82-0.96) from T1- or T2-weighted images and inter-rater agreement was slightly greater using T1-weighted images (ICC = 0.73-0.88) than T2-weighted images (ICC = 0.66-0.82). Signal intensity measurements on T2-weighted images were found to have almost perfect intra- and inter-rater reliability (ICC = 0.92-0.99). The correlation analysis demonstrated that the quantitative measures represent different constructs. The MAD and Bland-Altman Plots further confirmed the high reliability of the area ratio, MCs mean signal intensity and MCs total signal intensity measurements. CONCLUSION: Three quantitative measures are suggested to assess the severity of MCs, which provide reliable, precise measurements for research on the etiology, pathogenesis, and clinical relevance of MCs.

The prevalence and characteristics of thoracic magnetic resonance imaging findings in men.

STUDY DESIGN: A cross-sectional study of thoracic magnetic resonance image (MRI) findings. OBJECTIVE: To examine the prevalence of different thoracic MRI findings for T6-T12 and their associations with age and one another by level. SUMMARY OF BACKGROUND DATA: There is a dearth of descriptive epidemiology of thoracic MRI findings in the general population. METHODS: Thoracic MRIs of 524 men were assessed qualitatively and quantitatively for a variety of findings, including disc bulging, height and signal, vertebral deformities, endplate irregularities, osteophytes, and hemangiomas. Descriptive statistics, correlation coefficients and STATA's survey analysis were used. RESULTS: In the lower thoracic spine, 5.4% to 9.5% of the discs, depending on level, were qualitatively assessed as moderately to severely narrowed. Anterior bulging was more common than posterior, which was relatively rare and mild when present. Signal was lower in the midthoracic than lower discs. At least 1 moderate or severe vertebral deformity was found in 6.1% of the subjects, suggesting fracture, and hemangiomas were identified in 2.3% of subjects. Disc signal correlated most highly with age (r = 0.31-0.42). Qualitatively assessed disc height narrowing (r = 0.29-0.46) and quantitative disc height (r = 0.11-0.29) were associated with disc signal. Upper and lower endplate irregularities were associated with one another (r = 0.17-0.32), as were bulging and osteophytes, anteriorly (r = 0.35-0.61) and posteriorly (r = 0.26-0.45). CONCLUSION: Degenerative MRI findings beyond a mild grade were not commonly observed in the thoracic spine among 35-70-year-old men. Posterior bulges, in particular, were rare. The highest correlation with age existed for disc signal. Different MRI findings were associated with one another, but the magnitude of association varied by level. The effects of individual judgments and disc level on prevalence rates were apparent.

Prevalence and characteristics of upper or mid-back pain in Finnish men.

STUDY DESIGN: Descriptive epidemiologic study. OBJECTIVES: To examine the 1-year prevalence, severity, and frequency of mid-back pain in a general population sample of men, with comparisons to neck and low back pain. SUMMARY OF BACKGROUND DATA: No previous studies reporting the characteristics of mid-back pain in a general population were found. METHODS: A total of 600 Finnish men 35 to 70 years of age were drawn from a population-based twin sample and interviewed with standardized pain questions. RESULTS: The 1-year prevalence of mid-back pain was 17.0% (95% confidence interval, 14.3-19.7) compared to 64.0% (95% confidence interval, 60.6-67.5) for neck and 66.8% (95% confidence interval, 63.4-70.3) for low back pain. The frequency of pain over the previous year among those with mid- and low back pain was less than for neck pain. The mean severity of the worst pain episode was highest for low back pain followed by mid-back and neck pain, which were similar. Associated disability tended to be less frequent from mid-back pain (23.5% vs. 30.3%-41.1%). Odds ratios for neck and low back pain when mid-back pain was reported were 2.32 and 2.86, respectively. CONCLUSION: The prevalence of mid-back pain was approximately one fourth that of neck and low back pain and was somewhat less likely to be disabling. In cases of mid-back pain, spinal comorbidity was nearly always reported.