Radiographic findings in patients suspected of subacromial impingement syndrome: prevalence and reliability

OBJECTIVE

Aims were to (i) report prevalence and (ii) evaluate reliability of the radiographic findings in examinations of patients suspected of subacromial impingement syndrome (SIS), performed before a patient's first consultation at orthopaedic department.

MATERIALS AND METHODS

This cross-sectional study examined radiographs from 850 patients, age 18 to 63 years, referred to orthopaedic clinic on suspicion of SIS. Prevalence (%) of radiographic findings were registered. Inter- and intrarater reliability was analysed using expected and observed agreement (%), kappa coefficients, Bland-Altman plots, or intraclass coefficients.

RESULTS

A total of 850 patients with a mean age of 48.2 years (SD = 8.8) were included. Prevalence of the radiographic findings was as follows: calcification 24.4%, Bigliani type III (hooked) acromion 15.8%, lateral/medial acromial spurs 11.1%/6.6%, acromioclavicular osteoarthritis 12.0%, and Bankart/Hill-Sachs lesions 7.1%. Inter- and intrarater Kappa values for most radiographic findings ranged between 0.40 and 0.89; highest values for the presence of calcification (0.85 and 0.89) and acromion type (0.63 and 0.66). The inter- and intrarater intraclass coefficients ranged between 0.41 and 0.83; highest values for acromial tilt (0.79 and 0.83) and calcification area (0.69 and 0.81).

CONCLUSION

Calcification, Bigliani type III (hooked) acromion, and acromioclavicular osteoarthritis were prevalent findings among patients seen in orthopaedic departments on suspicion of SIS. Spurs and Bankart/Hill-Sachs lesions were less common. Optimal reliabilities were found for the presence of calcification, calcification area, and acromial tilt. Calcification qualities, acromion type, lateral spur, and acromioclavicular osteoarthritis showed suboptimal reliabilities. Newer architectural measures (acromion index and lateral acromial angle) performed well with respect to reliability.

Acquired Brain Injury Among Adolescents and Young Adults: A Nationwide Study of Labor Market Attachment

Purpose Young patients represent a particularly vulnerable group regarding vocational prognosis after an acquired brain injury (ABI). We aimed to investigate how sequelae and rehabilitation needs are associated with vocational prognosis up to 3 years after an ABI in 15-30-year-old patients. Methods An incidence cohort of 285 patients with ABI completed a questionnaire on sequelae and rehabilitation interventions and needs 3 months after the index hospital contact. They were followed-up for up to 3 years with respect to the primary outcome "stable return to education/work (sRTW)", which was defined using a national register of public transfer payments. Data were analyzed using cumulative incidence curves and cause-specific hazard ratios. Results Young individuals reported a high frequency of mainly pain-related (52%) and cognitive sequelae (46%) at 3 months. Motor problems were less frequent (18%), but negatively associated with sRTW within 3 years (adjusted HR 0.57, 95% CI 0.39-0.84). Rehabilitation interventions were received by 28% while 21% reported unmet rehabilitation needs, and both factors were negatively associated with sRTW (adjusted HR 0.66, 95% CI 0.48-0.91 and adjusted HR 0.72, 95% CI 0.51-1.01). Conclusions Young patients frequently experienced sequelae and rehabilitation needs 3 months post ABI, which was negatively associated with long-term labor market attachment. The low rate of sRTW among patients with sequelae and unmet rehabilitation needs indicates an untapped potential for ameliorated vocational and rehabilitating initiatives targeted at young patients.

Reducing Shoulder Complaints in Employees with High Occupational Shoulder Exposures: A Cluster-Randomised Controlled Study (The Shoulder-Café Study)

PURPOSE

To evaluate if a group-based Shoulder-Café intervention could reduce shoulder complaints more effectively than an individual-based control intervention in employees with shoulder complaints and high occupational shoulder exposures.

METHODS

A cluster-randomised controlled study of 109 participants from 60 companies in Central Denmark Region. Companies were randomised and allocated to either Shoulder-Café or control intervention. Participants in both interventions received a pamphlet on home-based shoulder exercises and a pamphlet with general information on reducing occupational shoulder exposures. They also had their occupational shoulder exposures assessed. Shoulder-Café participants additionally received three café-meetings with casual discussion, clinical shoulder evaluation, education about shoulder anatomy and occupational shoulder exposures, supervised exercises, workplace-oriented counselling, and an optional workplace visit. The primary outcome measure was the Oxford Shoulder Score (OSS) at 6-month follow-up. Secondary outcome measures were the OSS at 12 months, Fear-Avoidance Beliefs Questionnaire - Physical Activity at 6 and 12 months, and Patients' Global Impression of Change at 6 months. The study also included seven supplementary outcome measures.

RESULTS

Both groups improved from baseline to 6 months with respect to the primary outcome (P < 0.01). No group differences were found for the primary outcome (mean difference (MD) [95% confidence interval]: 0.3 [- 1.6; 2.2]) or secondary outcomes. The supplementary outcomes "felt informed about handling shoulder complaints" and "felt informed about reducing occupational exposures" at 6 months, and "Patients' Global Impression of Change" and "overall satisfaction" at 12 months favoured the Shoulder-Café intervention.

CONCLUSION

The Shoulder-Café intervention did not reduce shoulder complaints more effectively than the control intervention.

TRIAL REGISTRATION

The trial was registered at Clinicaltrials.gov on 19 May 2017 (ID: NCT03159910).

Return to Work After Surgery For Trapeziometacarpal Joint Osteoarthritis in Relation to Occupational Hand Force Requirements

PURPOSE

This study evaluated the hypothesis that higher occupational hand force requirements are related to slower return to work (RTW) after surgery for trapeziometacarpal joint osteoarthritis.

METHODS

Patients treated surgically for trapeziometacarpal joint osteoarthritis from 2001 to 2017 were identified in the Danish National Patient Register. Sustainable RTW (sRTW) was defined as the first period of 4 consecutive weeks without health-related public transfer payments, according to the Danish National Register on Public Transfer Payments. Occupational codes from the Danish Employment Classification Module were linked to a hand-arm job exposure matrix to obtain occupational hand force requirements for each patient. Cox regression models were used to analyze time until sRTW in relation to hand force requirements with adjustment for age, sex, type of surgery, preoperative sick leave, and calendar year of surgery.

RESULTS

The study included 2,090 patients. Within 104 weeks, 91% sustainably returned to work. The percentage of individuals in the subgroups that did not RTW was 8% of low-force- and medium-force-exposed patients and 14% of high-force-exposed patients. Medium and high occupational hand force requirements were associated with slower sRTW. The adjusted hazard ratio for sRTW was 0.84 (95% confidence interval, 0.74-0.95) for medium and 0.59 (95% confidence interval, 0.50-0.68) for high compared with low hand force requirements. Among patients who returned to work, patients with medium and high hand force requirements had median periods until sRTW of 16 and 18 weeks, respectively, compared with 10 weeks among patients with low hand force requirements.

CONCLUSIONS

The prognosis regarding RTW after surgery for trapeziometacarpal joint osteoarthritis is generally good, but patients with higher occupational hand force requirements can expect slower RTW.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Vocational/educational prognosis in adolescents and young adults with acquired brain injury: a nationwide cohort study

OBJECTIVE

To determine prognostic factors for work ability and employment/educational status among young patients referred to outpatient neurorehabilitation clinics after an acquired brain injury.

METHODS

A nationwide cohort study of 471 15-30-year-old patients who attended an interdisciplinary clinical assessment and provided questionnaire data at baseline and after one year. The outcomes were the Work Ability Score (WAS, 0-10 (best)) and employment/educational status after one year. Prognostic performance was analyzed using univariable regression and multivariable Ridge regression in a five-fold cross-validated procedure.

RESULTS

Preinjury, 86% of the patients were employed, while the percentage had decreased to 55% at baseline and 52% at follow-up. The model, which included clinical measures of function, showed moderate prognostic performance with respect to WAS (R2=0.29) and employment/educational status (area under the curve (AUC)=0.77). Glasgow Outcome Scale Extended (R2=0.15, AUC=0.68) and the cognitive subscale of the Functional Independence Measure (R2=0.09, AUC=0.64), along with fatigue measured with the Multidimensional Fatigue Inventory (R2=0.15, AUC=0.60) were the single predictors with the highest predictive performance.

CONCLUSION

Despite generally high scores in motor and cognitive tests, only about half of the patients were employed at baseline and this proportion remained stable. Global disability, cognitive sequelae and fatigue had the highest prognostic performance.

Agreement between an expert-rated mini job exposure matrix of occupational biomechanical exposures to the lower body and technical measurements or observation: a method comparison study

OBJECTIVES

Investigating the agreement between an expert-rated mini job exposure matrix (JEM) of lower body exposures and technical measurements of worktime spent standing/walking and observation-based estimates of time spent kneeling/squatting and total load lifted per workday.

METHODS

We chose 16 job titles from the 121 job groups in the lower body JEM and included them in the mini JEM. New expert ratings for the mini JEM were performed by the same five occupational physicians who performed the ratings for the lower body JEM. For each job title and type of exposure, the exposure estimates were a mean of the five independent ratings. Technical measurements of standing/walking for all 16 job titles, and for 8 job titles workplace observations were performed of kneeling/squatting and total load lifted per workday. Data were collected from September to December 2015 and supplemented by data from the NOMAD and DPhacto studies collected between 2011 and 2013. All data were collected in Denmark. Agreement between expert-based and measured/observed lower body exposures by job titles was evaluated using Spearman's rank correlation, Bland-Altman plots evaluated systematic deviations and limits of agreement (LoA).

RESULTS

Standing/walking showed a rank correlation of 0.55, kneeling/squatting 0.83 and total load lifted per workday 0.71. The mini JEM estimates did not systematically deviate from the technical measurements/observations for time spent standing/walking (mean difference 0.20 hours/workday, LoA -1.63, 2.03 hours/workday) and kneeling/squatting (mean difference -0.35 hours/workday, LoA -1.21, 0.51 hours/workday). For total load lifted per workday, the mini JEM systematically overestimated the exposures compared with the observations (mean difference -909 kg/workday, LoA -3000, 1147 kg/workday).

CONCLUSIONS

There was moderate to very high agreement between an expert-rated mini JEM of standing/walking, kneeling/squatting, and lifting exposures and corresponding technical measurements/observations. This method comparison study supports the use of the expert-based lower body JEM in large-scale occupational epidemiological studies.

Associations between single and combined occupational mechanical exposures and surgery for subacromial impingement syndrome: a nationwide Danish cohort study

OBJECTIVE

This study aimed to evaluate whether the risk of surgery for subacromial impingement syndrome (SIS) increases with the number of combined occupational mechanical exposures compared with single exposure.

METHODS

We reanalyzed data from a register-based cohort study of the entire Danish working population (N=2 374 403) with 14 118 events of surgery for SIS (2003-2008). Exposure information in 10-year windows was obtained by combining occupational codes with a job exposure matrix. For single and combined mechanical exposures, we created three exposure variables of the number of years with specific exposure intensities with or without co-existing mechanical exposures. We used logistic regression as survival analysis.

RESULTS

We found exposure-response relations for duration and intensity of each single mechanical exposure except for repetition. The single effect of arm elevation >90º reached a maximum adjusted odds ratio (OR_adj) of 1.7 [95% confidence interval (CI) 1.5-2.0], which increased to 1.8 (95% CI 1.5-2.0), 2.0 (95% CI 1.9-2.2), and 2.2 (95% CI 2.0-2.5) when combined with repetition, force, and both. When combining repetition with arm elevation >90º, force, and both, OR_adj increased from 1.5 (95% CI 1.3-1.8) to 2.1 (95% CI 1.8-2.4), 2.5 (95% CI 2.4-2.9), and 2.7 (95% CI 2.4-3.0). For force, OR_adj increased from 2.5 (95% CI 2.1-2.9) to 2.6 (95% CI 2.3-2.8), 2.8 (95% CI 2.4-3.2), and 3.0 (95% CI 2.6-3.4).

CONCLUSION

We found an increased risk of surgery for SIS with the number of combined exposures; the risk was especially pronounced when the combined exposures included force.

Characterization of persistent post-traumatic headache and management strategies in adolescents and young adults following mild traumatic brain injury

Characteristics of persistent post-traumatic headache (PTH) in young individuals are poorly known leading to diagnostic problems and diverse management. We aimed to describe headache phenotypes and self-reported management strategies in young individuals with PTH following mild traumatic brain injury (mTBI). A comprehensive structured questionnaire was used to evaluate headache phenotypes/characteristics and management strategies to relieve headache in 107, 15–30-year-old individuals with PTH. Around 4 months post-injury, migraine-like headache in combination with tension-type like headache (40%) was the most commonly encountered headache phenotype followed by migraine-like headache (36%). Around 50% reported aura-like symptoms before/during the headache attack. Medication-overuse headache was diagnosed in 10%. Stress, sleep disturbances, and bright lights were the most common trigger factors. More than 80% reported that their headache was worsened by work-related activity and alleviated by rest/lying down. Simple analgesics were commonly used (88%) whereas prophylactic drugs were rarely used (5%). Bedrest and physiotherapy were also commonly used as management strategies by 56% and 34% of the participants, respectively. In conclusion, most young individuals with PTH after mTBI presented with combined migraine-like and tension-type-like headache followed by migraine-like headache, only. Preventive headache medication was rarely used, while simple analgesics and bedrest were commonly used for short-term headache relief.

Self-Rated Executive Function and Health-Related Quality of Life in Young Adults With Persistent Post-Concussion Symptoms: A Cross-Sectional Study

OBJECTIVE

To assess self-reported executive dysfunction in young adult patients with persistent post-concussion symptoms (PCS) 2-6 months post-injury, and the association with self-reported Health-Related Quality of Life (HRQoL).

METHOD

This cross-sectional study carried out in a hospital setting was a secondary analysis of data from a separate randomized trial testing the effect of a novel intervention, "Get going After concussIoN " (GAIN), for persistent PCS. Patients (18-30 years) were recruited from a clinical cohort of patients with a hospital diagnosis of concussion or referred by primary care physicians. Main measures were The Behaviour Rating Inventory of Executive Function-Adult Version providing two index scores, that is, the Metacognitive Index (MI) and the Behavioural Regulation Index (BRI), and the Quality of Life after Brain Injury-Overall Scale.

RESULTS

Compared with normative data, patients had elevated scores (i.e., worse functioning) on both the MI and the BRI. In linear regression analysis, the MI score, but not the BRI score, was negatively associated with self-reported HRQoL (MI: slope = -.27, 95% confidence interval, CI [-.53, -.02], p = .03; BRI: slope = -.19, 95% CI [-.49, .13], p = .24), suggesting a positive association of subjective executive dysfunction and lower HRQoL. However, the association was attenuated after adjustment for self-reported psychological distress (MI: slope = -.09, 95% CI [-.34, .17], p = .51).

CONCLUSION

Self-reported executive dysfunction is common in young adult patients with persistent PCS, but not strongly associated with decreased HRQoL after adjusting for concurrent psychological distress.

Attachment and symptom reporting in adolescents and young adults after a concussion

BACKGROUND

The incidence of hospital-treated concussion is 100-300/100,000 person years. Reporting of long-lasting post-concussion symptoms (PCS) is estimated at 5-15%. Attachment insecurity is a potential vulnerability factor for physical illness and poorer disease outcomes in general. This study aimed to explore associations between attachment insecurity and PCS in young people sustaining a concussion.

METHODS

This cross-sectional study was embedded in a cohort of 15-30-year-old patients (n = 3080) 3 months after sustaining a concussion. Data were obtained from a database and questionnaires. PCS were measured by the Rivermead Post-Concussion Symptoms Questionnaire and attachment dimensions (anxiety and avoidance) by the Experiences in Close Relationships-Relationship Structures Questionnaire. Multiple linear regression models were performed to investigate the association between the attachment dimensions and PCS with adjustment for demographic, injury-related and psychological factors and with additional testing for interaction between the attachment dimensions.

RESULTS

In the final study sample, comprising 973 patients (31.6%), we found an interaction between the attachment dimensions. Hence, the effect of attachment anxiety on PCS was statistically insignificant at low avoidance (25th percentile) but significant at high avoidance (75th percentile, β = 0.64 (95%CI: 0.02; 1.26)), whereas the effect of attachment avoidance was significant regardless of level of attachment anxiety (25th percentile, β = 1.09 (95%CI: 0.18; 2.01); 75th percentile, β = 2.71 (95%CI: 1.80; 3.61)).

CONCLUSION

Attachment insecurity, especially characterised by high avoidance in combination with high anxiety, also called fearful attachment, is associated with PCS. Considering the attachment perspective can potentially improve health care for this patient group.

Predictors of disability in adolescents and young adults with acquired brain injury after the acute phase

AIM

To develop and validate a prediction model for disability among young patients with acquired brain injury (ABI) after the acute phase.

METHODS

Within a nationwide cohort of 446 15-30-year-old ABI-patients, we predicted disability in terms of Glasgow Outcome Scale - Extended (GOS-E) <7 12 months after baseline assessment in outpatient neurorehabilitation clinics. We studied 22 potential predictors covering demographic and medical factors, clinical tests, and self-reported fatigue and alcohol/drug consumption. The model was developed using multivariable logistic regression analysis and validated by 5-fold cross-validation and geographical validation. The model's performance was assessed by receiver operating characteristic curves and calibration plots.

RESULTS

Baseline assessment took place a median of 12 months post-ABI. Low GOS-E (range 1-8 (best)) and Functional Independence Measure (range 18-126 (best)) along with high mental fatigue (range 4-20 (worst)) predicted disability. The model showed high validity and performance with an area under the curve of 0.82 (95% confidence interval (CI) 0.77, 0.87) in the cross-validation and 0.81 (95% CI 0.73, 0.88) in the geographical validation.

CONCLUSION

We developed and validated a parsimonious model which effectively predicted disability. The model may be useful to guide decision-making in outpatient neurorehabilitation clinics treating young patients with ABI.

Microstructural changes in the brain after long-term post-concussion symptoms: A randomized trial

A recent randomized controlled trial in young patients with long-term post-concussion symptoms showed that a novel behavioral intervention "Get going After concussIoN" is superior to enhanced usual care in terms of symptom reduction. It is unknown whether these interventional effects are associated with microstructural brain changes. The aim of this study was to examine whether diffusion-weighted MRI indices, which are sensitive to the interactions between cellular structures and water molecules' Brownian motion, respond differently to the interventions of the above-mentioned trial and whether such differences correlate with the improvement of post-concussion symptoms. Twenty-three patients from the intervention group (mean age 22.8, 18 females) and 19 patients from the control group (enhanced usual care) (mean age 23.9, 14 females) were enrolled. The primary outcome measure was the mean kurtosis tensor, which is sensitive to the microscopic complexity of brain tissue. The mean kurtosis tensor was significantly increased in the intervention group (p = 0.003) in the corpus callosum but not in the thalamus (p = 0.78) and the hippocampus (p = 0.34). An increase in mean kurtosis tensor in the corpus callosum tended to be associated with a reduction in symptoms, but this association did not reach significance (p = 0.059). Changes in diffusion tensor imaging metrics did not differ between intervention groups and were not associated with symptoms. The current study found different diffusion-weighted MRI responses from the microscopic cellular structures of the corpus callosum between patients receiving a novel behavioral intervention and patients receiving enhanced usual care. Correlations with improvement of post-concussion symptoms were not evident.

Surgery for trapeziometacarpal osteoarthritis in relation to cumulative occupational hand force requirements: a Danish nationwide cohort study

OBJECTIVES

To evaluate if higher cumulative occupational hand force requirements are associated with higher risks of surgery for trapeziometacarpal osteoarthritis and with surgery earlier in life.

METHODS

The study was based on Danish national registers. Among all persons born in Denmark 1931 to 1990, we included those who had been employed for at least 5 years since 1991 by the end of 2000, or later when this employment criterion was reached, up until the end of 2016. Cumulative exposure estimates for 10-year time windows (force-years) were assessed by combining individual year-by-year information on occupational codes with an expert based hand-arm job exposure matrix. First-time events of surgery for trapeziometacarpal osteoarthritis 2001 to 2017 constituted the outcome. Surgery rates were analysed by a logistic regression technique equivalent to discrete survival analysis using a 1-year lag. We also calculated rate advancement periods.

RESULTS

A total of 2 860 448 persons contributed with around 48 million person-years of follow-up, during which 3977 cases appeared (821 among men and 3156 among women). Compared with <5 force-years, the adjusted OR (OR_adj) for ≥5 to <10 force-years was 1.39 (95% CI 1.14 to 1.68) and for ≥10 to 30 force-years 1.47 (95% CI 1.26 to 1.71) among men and 1.64 (95% CI 1.50 to 1.78) and 1.29 (95% CI 1.16 to 1.43) among women. The sex combined OR_adj were 1.59 (95% CI 1.47 to 1.72) and 1.36 (95% CI 1.25 to 1.48). Among the exposed, surgery was advanced by 3 to 7 years.

CONCLUSION

Medium/high cumulative hand force requirements were associated with elevated hazard rates of surgery for trapeziometacarpal osteoarthritis and advanced the time of surgery by several years.

Acute myocardial infarction in relation to physical activities at work: a nationwide follow-up study based on job-exposure matrices

Objective This study aimed to evaluate sex-specific risks of acute myocardial infarction (AMI) according to lifting and standing/walking at work. Methods The study population included 1.15 million Danish wage earners. Annual job codes from 1976 onwards were linked to specific exposures using job-exposure matrices (JEM). Cases of AMI during follow-up 1996-2016 were retrieved from national registers. Incidence rate ratios (IRR) were computed by Poisson regression adjusting for demographic and JEM-assessed lifestyle factors. Models addressed physical activities at work the previous 0-2 years (short-term risk) and cumulative physical activities (long-term risk). Results During 21.4 million person-years of follow-up, 22 037 AMI occurred in men and 6942 in women. Exposure-response relationships between recent physical activities at work and AMI were not evident. In men, the fully adjusted long-term IRR for the highest of five exposure categories compared to the lowest were 1.09 [95% confidence interval (CI) 1.03-1.15] for lifting and 1.01 (95% CI 0.96-1.07) for standing/walking. In women, the corresponding figures were 1.27 (95% CI 1.15-1.40) and 1.18 (95% CI 1.07-1.30). The latter risk estimate was strongly attenuated, and the trend became insignificant when adjusted for lifting. Findings were only partially supported by sensitivity analyses. Conclusion The study provides limited support to the hypothesis that long-term lifting and standing/walking at work is related to increased risk of AMI. Possible effects of acute physical exertion are not addressed and bias towards the null because of crude exposure assignment cannot be ruled out.

Novel interdisciplinary intervention, GAIN, vs. enhanced usual care to reduce high levels of post-concussion symptoms in adolescents and young adults 2-6 months post-injury: A randomised trial

BACKGROUND

Evidence for effective interventions to prevent long-term sequelae after concussion is sparse. This study aimed to test the efficacy of Get going After concussIoN (GAIN), an interdisciplinary, individually-tailored intervention of 8 weeks duration based on gradual return to activities and principles from cognitive behavioural therapy.

METHODS

We conducted an open-label, parallel-group randomised trial in a hospital setting in Central Denmark Region. Participants were 15-30-year-old patients with high levels of post-concussion symptoms (PCS) 2-6 months post-concussion (i.e., a score ≥20 on the Rivermead Post-concussion Symptoms Questionnaire (RPQ)). They were randomly assigned (1:1) to either enhanced usual care (EUC) or GAIN+EUC. Masking of participants and therapists was not possible. The primary outcome was change in RPQ-score from baseline to 3-month FU. All analyses were done on an intention-to-treat basis using linear mixed-effects models. This trial is registered with ClinicalTrials.gov, number NCT02337101.

FINDINGS

Between March 1, 2015, and September 1, 2017, we included 112 patients. Patients allocated to GAIN+EUC (n=57) reported a significantly larger reduction of PCS than patients allocated to EUC (n=55) with a mean adjusted difference in improvement of 7·6 points (95% confidence interval (CI) 2·0-13·1, p=0·008), Cohen's d=0·5 (95% CI 0·1-0·9). Number needed to treat for prevention of one additional patient with RPQ ≥20 at 3-month FU was 3·6 (95% CI 2·2-11·3). No adverse events were observed.

INTERPRETATION

Compared with EUC, GAIN+EUC was associated with a larger reduction of post-concussion symptoms at 3-month FU.

FUNDING

Central Denmark Region and the foundation "Public Health in Central Denmark Region - a collaboration between municipalities and the region".

Reducing shoulder complaints in employees with high occupational shoulder exposures: study protocol for a cluster-randomised controlled study (The Shoulder-Café Study)

Background

In Denmark, exercise therapy in combination with work modification is the first-choice treatment for persons with shoulder complaints and high occupational shoulder exposures. To obtain this treatment they must visit several healthcare providers, which makes usual care fragmented and uncoordinated. Therefore, we developed a new intervention which unifies the expertise that is needed. The main hypotheses are that a group-based Shoulder-Café intervention will more effectively reduce (1) shoulder complaints and (2) occupational shoulder exposures than an individual-based Shoulder-Guidance intervention (active control – enhanced usual care).

Methods

A cluster-randomised trial is conducted including 120 employees with high occupational shoulder exposures. Companies (clusters) are randomised to either Shoulder-Café or Shoulder-Guidance with a 1:1 allocation ratio. Participants are 18–65 years old and have an Oxford Shoulder Score (OSS) ≤ 40. Both interventions include a home-based shoulder-exercise programme, assessment of shoulder exposures by technical measurements and self-report, and general information on how to reduce shoulder exposures. The Shoulder-Café course also includes three café meetings with physiotherapist-supervised exercises, clinical shoulder evaluation, education on shoulder anatomy, workplace-orientated counselling, and an opportunity for a workplace visit by a health and safety consultant. The primary outcomes are the OSS at 6-month follow-up (hypothesis I), and the mean number of min/day with the arm elevated > 60° shortly after the end of the intervention (hypothesis II). We will use a mixed-model analysis that allows for company clustering, and data will be analysed according to the intention-to-treat principle.

Discussion

Persons with shoulder complaints and high occupational shoulder exposures are an obvious target group for secondary prevention efforts. We developed the Shoulder-Café to reduce shoulder complaints and shoulder exposures while unifying the expertise that is needed to evaluate and treat shoulder complaints. If the intervention is effective, it would warrant widespread implementation.

Trial registration

Clinicaltrials.gov, ID: NCT03159910. Registered on 18 May 2017

Influence of errors in job codes on job exposure matrix-based exposure assessment in the register-based occupational cohort DOC*X

Objective Job-exposure matrices (JEM) may be efficient for exposure assessment in occupational epidemiological studies, but they rely on valid job information. We evaluated the agreement between JEM-based exposure estimates according to self-reported job titles converted to DISCO-88 codes and according to register-based DISCO-88 codes in the Danish Occupational Cohort with eXposure data (DOC*X). Furthermore, we evaluated the agreement between these two sets of DISCO-88 codes. Methods We used JEM regarding wood dust, lifting, standing/walking, arm elevation >90°, and noise from DOC*X. Participants from previous questionnaire studies were assigned JEM-based exposure estimates using (i) self-reported job titles converted to DISCO-88 codes and (ii) DISCO-88 codes registered in DOC*X, in four time periods (1976-78: N=7707; 1981-83: N=2193; 1991-94: N=2664; 2004: N=11 782). Agreement between the exposure estimates and between the DISCO-88 codes (four-digit levels, 1-4) was evaluated by kappa (κ) statistics. Sensitivities were calculated using the self-reported observation as the gold standard. Results We found substantial agreement (κ>0.60) between exposure estimates for all types of job-exposures and all time periods except for one κ. Low sensitivity (30-65%) was found for the period 1981-83, but for the other time periods the sensitivities varied between 60-91%. For individual 4-digit DISCO-88 codes, the sensitivities varied substantially and overall the sensitivities increased by lower digit level of DISCO-88. Conclusion The validity of the DISCO-88 codes in DOC*X was generally high. Substantial agreement was found for the JEM-based exposure estimates and the DISCO-88 codes per se, although the DISCO-88 code-specific agreement varied across digit levels and time periods.

Persistent postoperative pain after inguinal hernia repair in relation to occupational lifting and standing/walking: a 6-month follow-up study

OBJECTIVES

This study aims to evaluate the risk of persistent postoperative pain after inguinal hernia repair in relation to occupational lifting and standing/walking.

METHODS

We conducted a 6-month follow-up study that included all men with an inguinal hernia repair registered in the Danish Hernia Database from 1 January 2015 to 31 October 2016, who were born from 1 October 1949 to 1 October 1998, and who were alive, living in Denmark, and active in the labour market in the week before surgery. Members of the cohort received a questionnaire 6 months after surgery. Exposure estimates were allocated by combining self reported job titles with a job exposure matrix. Prevalence ratios of persistent postoperative pain during activity ≥2 on a numerical rating scale (range 0-10) according to occupational lifting and standing/walking were estimated using Poisson regression.

RESULTS

Of 4817 eligible patients, 2609 (54%) returned the questionnaire and 2508 contributed to the analyses. A total of 473 men (18.9%) reported persistent postoperative pain. In the group lifting >1000 to 6125 kg/day, the prevalence was 26.8% compared with 17.5% in the minimally exposed group; adjusted prevalence ratio: 1.44 (95% CI 1.16 to 1.79). For standing/walking >6 hours/day, the prevalence was 23.6% compared with 17.0% in the group standing <4 hours/day; adjusted prevalence ratio: 1.18 (95% CI 0.92 to 1.50).

CONCLUSIONS

The risk of persistent postoperative pain after inguinal hernia repair was elevated among men with occupational lifting exposures >1000 kg/day. This finding suggests a preventive potential.

Design of an early intervention for persistent post-concussion symptoms in adolescents and young adults: A feasibility study

BACKGROUND

About 5-15 % of patients with concussion experience persistent post-concussion symptoms (PCS) longer than 3 months post-injury.

OBJECTIVE

To explore the feasibility of a new intervention for young patients with persistent PCS and long-term changes after intervention.

METHODS

Thirty-two consecutive patients (15-30 years) with persistent PCS 2-4 months post-injury were recruited from a cohort study or referred to a non-randomized feasibility study of an individually tailored, 8-week, multidisciplinary intervention. Assessment was performed at baseline, end of intervention (EOI), and at 3- and 12-month follow-up (FU). Main measures were The Experience of Service Questionnaire (ESQ), Rivermead Post-Concussion Symptoms Questionnaire (RPQ) and The Quality of Life after Brain Injury - Overall Scale (QOLIBRI-OS).

RESULTS

Twenty-three (72%) patients completed the intervention. The ESQ demonstrated high patient satisfaction. There was a decrease of PCS and an increase in quality of life from baseline to EOI: RPQ score -8.9 points, 95% CI 4.5 to 13.3, p < 0.001; QOLIBRI-OS score +10.5 points, 95% CI 2.5 to 18.5, p = 0.010. Improvement was maintained at 3- and 12-month FU.

CONCLUSION

The new early intervention is feasible and may prevent chronification of PCS. An RCT is currently performed to evaluate the effect of the intervention.

Improving work for the body - a participatory ergonomic intervention aiming at reducing physical exertion and musculoskeletal pain among childcare workers (the TOY-project): study protocol for a wait-list cluster-randomized controlled trial

Background

The prevalence of musculoskeletal pain (MSP) is persistently high throughout the world. Work-related factors such as high physical workload (lifting, bending and twisting of the back) are considered to be among the main causes of MSP. Work in childcare includes the need to lift, carry, and support children in a range of activities, requiring several demanding postures and movements, such as bending forward and twisting of the back and sitting on the floor. Participatory ergonomics may represent a solution for decreasing the physical workload to reduce MSP. We present the protocol of a study aiming to evaluate the effect and process of a participatory ergonomics intervention designed to reduce physical exertion during work and MSP (including MSP interfering with work) among childcare workers.

Methods/design

This study will use a two-arm cluster-randomized design employing a wait-list control, with childcare institutions forming the clusters. Three workshops will be conducted during the 4-month intervention period. Participants will identify risk factors for strenuous work and MSP, develop solutions for reducing the identified risk factors, and implement them in their team. An ergonomic consultant will guide the process. The data collection will consist of questionnaires and objective measures of heart rate and physical activity, observations of physical workload, and information on sickness absence based on company records. Primary outcomes are physical exertion during work and MSP (including pain-related work interference) measured at 4 months. Secondary outcomes measured at 4 months are sickness absence due to MSP; objectively measured occupational physical activity and heart rate; and self-reported self-efficacy, employee involvement, and need for recovery. Alongside the trial, a process evaluation and an economic evaluation will be conducted.

Discussion

The study will evaluate the effect and process of a participatory ergonomics intervention to reduce physical exertion at work and MSP among childcare workers. By performing a cluster-randomized controlled trial with an effect evaluation based on both objective and self-reported measures with the addition of a process evaluation and economic evaluation, this study will contribute to the evidence for prevention of MSP among a less studied occupational group. Results are expected in 2018–2019.

Trial registration

ISRCTN, ISRCTN10928313. Registered on 11 January 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2788-z) contains supplementary material, which is available to authorized users.

Disability and return to work after MRI on suspicion of scaphoid fracture: Influence of MRI pathology and occupational mechanical exposures

Objectives

We aimed to determine the prognosis after early MRI on clinical suspicion of scaphoid fracture, hypothesising that MRI pathology is associated with more disability and that MRI pathology and high occupational mechanical hand-arm exposures are associated with slower return to work (RTW).

Methods

We conducted a follow-up study of a cohort of 469 patients, who were scanned in the period 2006 to 2010. The respondents constituted our cohort for disability analysis and the subset that was in the labour market at the time of the trauma constituted our sub-cohort for RTW analysis. Questionnaires included disability scores, job title, and lifestyle factors. Job titles were linked with a job exposure matrix to estimate occupational exposures. Register information was obtained on time until RTW. We used logistic regression analysis of disability and Cox regression analysis of time until RTW.

Results

The proportion that responded was 53% (249/469) for the disability analysis and 59% (125/212) for the RTW analysis. The mean age at follow up was 43.5 years, the mean time since trauma was 4.8 years, 53% had injury of the dominant hand, and 54% had MRI pathology. Men constituted 43% of the cohort and 56% of the sub-cohort. MRI pathology was not associated with more disability [e.g., for a 'Disabilities of the Arm Shoulder and Hand'-score ≥20 the odds ratio was 0.58 (95% confidence interval 0.26–1.17)]. Patients without MRI pathology and with low occupational exposures were off work for an average of four weeks. Patients with MRI pathology or high occupational exposures were off work for twice as long time.

Conclusion

MRI pathology was not associated with more disability. For patients, who were in the labour market at the time of the trauma, MRI pathology and high occupational mechanical hand-arm exposures were associated with slower RTW.

Predicting shoulder function after constraint-induced movement therapy: a retrospective cohort study

Background Several predictors have been associated with upper extremity (UE) recovery after stroke, but characteristics that predict shoulder function after constraint-induced movement therapy (CIMT) have not yet been identified. Objectives To identify predictors associated with satisfactory shoulder function in patients with reduced shoulder function at admission to CIMT. Methods One hundred and seventy five patients were treated using CIMT while in a specialized inpatient hospital. Satisfactory shoulder function was defined according to the functional ability scale of the Wolf Motor Function test. Predictors of satisfactory shoulder function after CIMT were identified using multivariable logistic regression. Results Better distal arm function and good proximal shoulder function on admission to CIMT were strong predictors of satisfactory shoulder function, while age and time of admission to CIMT since stroke were not. Seventeen percent of all CIMT-participants with reduced shoulder function pre-CIMT reached a level of satisfactory shoulder function after CIMT. Discussion A substantial part of patients with reduced shoulder function reached a level of satisfactory shoulder function after CIMT. Intensive CIMT training, comprising tasks that require both distal and proximal UE function, may increase shoulder function in patients with a potential functional reserve.

Diffusion MRI findings in patients with extensive and minimal post-concussion symptoms after mTBI and healthy controls: a cross sectional study

PRIMARY OBJECTIVES

We hypothesized that the microstructure of the corpus callosum, thalamus and hippocampus, as measured with diffusion and Mean of the Kurtosis Tensor (MKT) MRI, differs between healthy subjects and patients with extensive and minimal post-concussion symptoms (PCS) and that MKT measures correlate with PCS severity and self-reported cognitive symptoms.

RESEARCH DESIGN

A cross-sectional study comparing patients with extensive PCS and patients with minimal PCS 2-5 months after mild traumatic brain injury (mTBI) with each other and with an external healthy control group.

METHODS AND PROCEDURES

Diffusion MRI was obtained in 25 patients with extensive PCS and in 25 patients with minimal PCS as measured by the Rivermead Post-concussion Symptoms Questionnaire. The patients were matched on age, sex and time since accident. Data from an external healthy control group (n = 27) was included.

MAIN OUTCOME AND RESULTS

There was no difference in MKT between the two groups with mTBI and no correlation between MKT and PCS. There was no difference between the three groups in other diffusion measures.

CONCLUSIONS

Our results did not point to microstructural changes in the corpus callosum, thalamus and hippocampus in relation to PCS after mTBI.

Prevalence and severity of fatigue in adolescents and young adults with acquired brain injury: A nationwide study

Objective: To investigate the prevalence and severity of fatigue in adolescents and young adults with acquired brain injury (ABI) compared with healthy controls (HCs) and to examine associations between fatigue and gender, age and level of education. Methods: This cross-sectional study included 15-30 year old patients with ABI and a convenience sample of 15-30 year old HCs. All participants completed the 20-item Multidimensional Fatigue Inventory (MFI-20). Pathological fatigue was defined as "General Fatigue" ≥12. Adjusted mean differences between groups were calculated using multivariate analysis of covariance (MANCOVA). The adjusted prevalence proportion ratio (PPR_adj) of pathological fatigue was calculated using Poisson regression. Results: The patients (n = 334) had higher scores than the HCs (n = 168) on all MFI-20 subscales with adjusted mean differences ranging from 1.7 to 4.7 and a higher prevalence of pathological fatigue (73% versus 29%), PPR_adj 2.7 (95% confidence interval 2.1-3.5). Female patients experienced more fatigue than males on the "General Fatigue" and "Reduced Activity" subscales, while no gender differences were found in the HC group. Patients and HCs with elementary education had elevated scores on the "Reduced Activity" and "Mental Fatigue" subscales. Age was not associated with any of the subscale scores. Conclusion: Young patients with ABI had markedly higher prevalence and severity of fatigue than HCs. Age (15-30 years) was not associated with fatigue. No clear patterns of associations were evident with gender and level of education. Abbreviations: ABI: acquired brain injury; CI: confidence interval; GF: general fatigue; GOSE: Glasgow Outcome Scale Extended; HC: healthy control; MANCOVA: multivariate analysis of covariance; MF: mental fatigue; MFI-20: Multidimensional Fatigue Inventory-20; PF: physical fatigue; RA: reduced activity; RM: reduced motivation; TBI: traumatic brain injury.

Surgery for subacromial impingement syndrome in relation to intensities of occupational mechanical exposures across 10-year exposure time windows

Objectives

We aimed to identify intensities of occupational mechanical exposures (force, arm elevation and repetition) that do not entail an increased risk of surgery for subacromial impingement syndrome (SIS) even after prolonged durations of exposure. Additionally, we wanted to evaluate if exposure to hand-arm vibration (HAV) is an independent risk factor.

Methods

We used data from a register-based cohort study of the entire Danish working population (n=2 374 403). During follow-up (2003–2008), 14 118 first-time events of surgery for SIS occurred. For each person, we linked register-based occupational codes (1993–2007) to a general population job exposure matrix to obtain year-by-year exposure intensities on measurement scales for force, upper arm elevation >90° and repetition and expert rated intensities of exposure to HAV. For 10-year exposure time windows, we calculated the duration of exposure at specific intensities above minimal (low, medium and high). We used a logistic regression technique equivalent to discrete survival analysis adjusting for cumulative effects of other mechanical exposures.

Results

We found indications of safe exposure intensities for repetition (median angular velocity <45°/s), while force exertion ≥10% of maximal voluntary electrical activity and upper arm elevation >90° >2 min/day implied an increased risk reaching ORs of 1.7 and 1.5 after 10 years at low intensities. No associations were found for HAV.

Conclusions

We found indications of safe exposure intensities for repetition. Any intensities of force and upper arm elevation >90° above minimal implied an increased risk across 10-year exposure time windows. No independent associations were found for HAV.

Inguinal hernia repair among men in relation to occupational mechanical exposures and lifestyle factors: a longitudinal study

OBJECTIVES

To evaluate exposure-response relationships between occupational mechanical exposures and first-time lateral and medial inguinal hernia repair and effects of lifestyle factors. To estimate if occupational mechanical exposures advance the repairs.

METHODS

This longitudinal study was based on a cohort of men aged 18-65 years with questionnaire data from the Musculoskeletal Research Database at the Danish Ramazzini Centre. We estimated occupational mechanical exposures using a job exposure matrix. First-time inguinal hernia repairs from 1998 to 2014 were identified in the Danish Hernia Database. We used Cox regression analyses and calculated excess fractions among the exposed and rate advancement periods (RAPs).

RESULTS

Among 17 967 men, we identified 382 lateral and 314 medial repairs. The risk of lateral repairs increased with time spent standing/walking with an HR of 1.45 (95% CI 1.12 to 1.88) for ≥6 hours/day versus <4 hours/day, corresponding to an excess fraction of cases of 31% in the group with ≥6 hours/day. This group had a RAP of 6.7 (95% CI 2.6 to 10.8) years. Medial repairs were not associated with occupational mechanical exposures. A body mass index ≥30 kg/m² showed lower HRs for both repair types. Leisure-time physical activity and smoking status were not related to any of the outcomes.

CONCLUSIONS

Assuming a causal relationship, the results suggest that around 30% of all first-time lateral inguinal hernia repairs in the highest exposure category would be preventable if the time spent standing/walking could be reduced from ≥6 to <4 hours/day. The repairs might even be postponed by 6-7 years.

Reversible median nerve impairment after three weeks of repetitive work

Objectives The aim of this study was to evaluate the development of impaired median nerve function in relation to hand-intensive seasonal work. We hypothesized that at end-season, median nerve conduction would be impaired and then recover within weeks. Methods Using nerve conduction studies (NCS), we examined median nerve conduction before, during, and after engaging in 22 days of mink skinning. For a subgroup, we used goniometry and surface electromyography to characterize occupational mechanical exposures. Questionnaire information on symptoms, disability, and lifestyle factors was obtained. Results The study comprised 11 male mink skinners with normal median nerve conduction at pre-season (mean age 35.7 years, mean number of seasons with skinning 8.9 years). Mink skinning was characterized by a median angle of wrist flexion/extension of 16º extension, a median velocity of wrist flexion/extension of 22 °/s, and force exertions of 11% of maximal voluntary electrical activity. At end-season, mean distal motor latency (DML) had increased 0.41 ms (P<0.001), mean sensory nerve conduction velocity (SNCV) digit 2 had decreased 6.3 m/s (P=0.004), and mean SNCV digit 3 had decreased 6.2 m/s (P=0.01); 9 mink skinners had decreases in nerve conduction, 5 fulfilled electrodiagnostic criteria and 4 fulfilled electrodiagnostic and clinical criteria (a positive Katz hand diagram) for carpal tunnel syndrome (CTS). Three to six weeks post-season, the changes had reverted to normal. Symptom and disability scores showed corresponding changes. Conclusions In this natural experiment, impaired median nerve conduction developed during 22 days of repetitive industrial work with moderate wrist postures and limited force exertion. Recovery occurred within 3-6 weeks post-season.

Exposure-response relationships between movements and postures of the wrist and carpal tunnel syndrome among male and female house painters: a retrospective cohort study

OBJECTIVES

To investigate exposure-response relationships between measured movements and postures of the wrist and the incidence of carpal tunnel syndrome (CTS), and any modifications by sex.

METHODS

In 2011, we established a historical cohort of 9364 members of the Painters' Union in Denmark. Self-reported task distributions were obtained by questionnaire (53% responded) and combined with sex-specific task exposure matrices to get individual estimates of exposure intensity, that is, velocity of wrist flexion/extension, mean power frequency (MPF) and non-neutral wrist postures. Exposure duration was assessed from yearly working proportions. Registered first-time hospital discharge CTS diagnoses and CTS surgery were collected as outcomes. The cohort was followed from 1994 to 2010. Log-linear Poisson regression was used.

RESULTS

For CTS diagnoses, the adjusted incidence rate ratios (IRRs) increased with increasing wrist velocity (IRR=1.37 (95% CI 1.10 to 1.71) per °/s) and MPF (IRR=1.53 (95% CI 1.21 to 1.91) per 0.01 Hz). For CTS surgery, the results were similar. The outcomes were not related to non-neutral postures or exposure duration. The adjusted IRRs for women were higher than those for men. There were no multiplicative interaction effects between exposure intensity, exposure duration and sex. However, the absolute incidence rates (IRs) increased at a steeper rate for women than for men, indicating an additive interaction.

CONCLUSIONS

The incidence of CTS increased with increasing velocity of wrist flexion/extension and MPF of wrist movements. The relative increase in incidence rates was the same for women and men, but the absolute incidence rates increased at a steeper rate for women than for men.

The Use of Physiotherapy among Patients with Subacromial Impingement Syndrome: Impact of Sex, Socio-Demographic and Clinical Factors

Background

Physiotherapy with exercises is generally recommended in the treatment of patients with subacromial impingement syndrome (SIS).

Objective

We aimed to investigate the use of physiotherapy in patients with SIS in Danish hospital settings as part of initial non-surgical treatment and after SIS-related surgery and to evaluate to which extent sex, socio-demographic and clinical factors predict the use of physiotherapy.

Methods

Using national health registers, we identified 57,311 patients who had a first hospital contact with a diagnosis of ICD-10, groups M75.1–75.9, 1 July 2007 to 30 June 2011. Records of physiotherapy were extracted within 52 weeks after first contact (or until surgery), and for surgically treated patients within 26 weeks after surgery. Predictors of the use of physiotherapy after first contact and after surgery were analysed as time-to-event.

Results

Within 52 weeks after first contact, 43% of the patients had physiotherapy and 30% underwent surgery. Within 26 weeks after surgery, 80% had a record of physiotherapy. After first contact and after surgery, exercise was part of physiotherapy in 65% and 84% of the patients, respectively. A public hospital contact, physiotherapy before hospital contact, administrative region, female sex, a diagnosis of other or unspecified disorders (M75.8-M75.9), and surgical procedure predicted higher use of physiotherapy. Low education level predicted slightly lower use of physiotherapy after first contact, but not after surgery.

Conclusion

In patients with SIS in Danish hospital settings, physiotherapy was more often used after surgery than as part of initial non-surgical treatment. The use of physiotherapy was less common among men than women, whereas unequal use of physiotherapy in relation to education level was not noticeable. The use of physiotherapy with exercises in initial non-surgical treatment was relatively limited.

Proteomics perspectives in rotator cuff research: a systematic review of gene expression and protein composition in human tendinopathy

BACKGROUND

Rotator cuff tendinopathy including tears is a cause of significant morbidity. The molecular pathogenesis of the disorder is largely unknown. This review aimed to present an overview of the literature on gene expression and protein composition in human rotator cuff tendinopathy and other tendinopathies, and to evaluate perspectives of proteomics--the comprehensive study of protein composition--in tendon research.

MATERIALS AND METHODS

We conducted a systematic search of the literature published between 1 January 1990 and 18 December 2012 in PubMed, Embase, and Web of Science. We included studies on objectively quantified differential gene expression and/or protein composition in human rotator cuff tendinopathy and other tendinopathies as compared to control tissue.

RESULTS

We identified 2199 studies, of which 54 were included; 25 studies focussed on rotator cuff or biceps tendinopathy. Most of the included studies quantified prespecified mRNA molecules and proteins using polymerase chain reactions and immunoassays, respectively. There was a tendency towards an increase of collagen I (11 of 15 studies) and III (13 of 14), metalloproteinase (MMP)-1 (6 of 12), -9 (7 of 7), -13 (4 of 7), tissue inhibitor of metalloproteinase (TIMP)-1 (4 of 7), and vascular endothelial growth factor (4 of 7), and a decrease in MMP-3 (10 of 12). Fourteen proteomics studies of tendon tissues/cells failed inclusion, mostly because they were conducted in animals or in vitro.

CONCLUSIONS

Based on methods, which only allowed simultaneous quantification of a limited number of prespecified mRNA molecules or proteins, several proteins appeared to be differentially expressed/represented in rotator cuff tendinopathy and other tendinopathies. No proteomics studies fulfilled our inclusion criteria, although proteomics technologies may be a way to identify protein profiles (including non-prespecified proteins) that characterise specific tendon disorders or stages of tendinopathy. Thus, our results suggested an untapped potential for proteomics in tendon research.

Combined musculoskeletal pain in the upper and lower body: associations with occupational mechanical and psychosocial exposures

PURPOSE

Pain in more than one site is common in working populations. We aimed to characterise combined pain (pain in the upper and lower body) and to evaluate whether the prevalence of combined pain is positively related to combined occupational mechanical exposures to the upper and lower body and to high psychosocial job strain.

METHODS

This cross-sectional study was based on questionnaire data from the Musculoskeletal Research Database at the Danish Ramazzini Centre. The study included 14,081 men and 20,173 women. Occupational exposures were assessed by job exposure matrices. We analysed the prevalence of pain limited to the upper body, pain limited to the lower body, and combined pain in relation to occupational exposures using Poisson regression.

RESULTS

During the last year, 23.2 % of the men and 33.9 % of the women reported combined pain, which was characterised by somatisation, illness worrying, and low SF-36 scores. For men, the adjusted prevalence ratio for combined pain was 1.51 [95 % confidence interval (95 % CI) 1.40-1.64] in relation to exposures limited to the upper body and 2.24 (95 % CI 2.11-2.39) in relation to combined exposures. For women, the corresponding adjusted prevalence ratios were 1.56 (95 % CI 1.50-1.63) and 1.55 (95 % CI 1.50-1.61). High job strain was related to pain among men, only.

CONCLUSION

Combined pain may in part be explained by local effects of occupational mechanical exposures acting at more than one site.

Occupational mechanical exposures and reoperation after first-time inguinal hernia repair: a prognosis study in a male cohort

PURPOSE

The aim of this study was to evaluate exposure-response relationships between occupational mechanical exposures and risk of reoperation after inguinal hernia repair.

METHODS

Using register information, we identified all men born in Denmark 1938-1988, who had their first inguinal hernia repair 1998-2008, and who were 18-65 years old and active in the labour market at the time of surgery. The Danish Hernia Database provided information on repairs and reoperations. We used registered occupational codes and a job exposure matrix based on experts' ratings to estimate total load lifted per day, frequency of heavy lifting, and number of hours per day spent standing/walking. We also obtained register information on sickness absence. Multivariable Cox regression analysis was used.

RESULTS

The cohort comprised 34,822 patients. We did not reveal exposure-response relationships between occupational mechanical exposures and the hazard ratio (HR) of reoperation. The percentage of patients with >2 weeks of sickness absence within 8 weeks after surgery increased with total load lifted per day from 15 to 53%. Longer sickness absence was associated with an increased HR of reoperation, but within strata of sickness absence, we found no increase in the HR of reoperation with increasing exposures.

CONCLUSION

We did not find indications that the HR of reoperation was related to occupational mechanical exposures, even after accounting for a potential protective effect of sickness absence. Hence, the exposure-related prolonged duration of sickness absence could not be explained by exposure-related complications that led to reoperation.

An expert-based job exposure matrix for large scale epidemiologic studies of primary hip and knee osteoarthritis: the Lower Body JEM

BACKGROUND

When conducting large scale epidemiologic studies, it is a challenge to obtain quantitative exposure estimates, which do not rely on self-report where estimates may be influenced by symptoms and knowledge of disease status. In this study we developed a job exposure matrix (JEM) for use in population studies of the work-relatedness of hip and knee osteoarthritis.

METHODS

Based on all 2227 occupational titles in the Danish version of the International Standard Classification of Occupations (D-ISCO 88), we constructed 121 job groups comprising occupational titles with expected homogeneous exposure patterns in addition to a minimally exposed job group, which was not included in the JEM. The job groups were allocated the mean value of five experts' ratings of daily duration (hours/day) of standing/walking, kneeling/squatting, and whole-body vibration as well as total load lifted (kg/day), and frequency of lifting loads weighing ≥20 kg (times/day). Weighted kappa statistics were used to evaluate inter-rater agreement on rankings of the job groups for four of these exposures (whole-body vibration could not be evaluated due to few exposed job groups). Two external experts checked the face validity of the rankings of the mean values.

RESULTS

A JEM was constructed and English ISCO codes were provided where possible. The experts' ratings showed fair to moderate agreement with respect to rankings of the job groups (mean weighted kappa values between 0.36 and 0.49). The external experts agreed on 586 of the 605 rankings.

CONCLUSION

The Lower Body JEM based on experts' ratings was established. Experts agreed on rankings of the job groups, and rankings based on mean values were in accordance with the opinion of external experts.

Occupational lifting, fetal death and preterm birth: findings from the Danish National Birth Cohort using a job exposure matrix

Objective

We examined the association between occupational lifting during pregnancy and risk of fetal death and preterm birth using a job exposure matrix (JEM).

Methods

For 68,086 occupationally active women in the Danish National Birth Cohort, interview information on occupational lifting was collected around gestational week 16. We established a JEM based on information from women, who were still pregnant when interviewed. The JEM provided mean total loads lifted per day within homogeneous exposure groups as informed by job and industry codes. All women were assigned an exposure estimate from the JEM. We used Cox regression models with gestational age as underlying time variable and adjustment for covariates.

Results

We observed 2,717 fetal deaths and 3,128 preterm births within the study cohort. No exposure-response relation was observed for fetal death, but for women with a prior fetal death, we found a hazard ratio (HR) of 2.87 (95% CI 1.37, 6.01) for stillbirth (fetal death ≥22 completed gestational weeks) among those who lifted >200 kg/day. For preterm birth, we found an exposure-response relation for primigravid women, reaching a HR of 1.43 (95% CI 1.13, 1.80) for total loads >200 kg per day. These findings correspond to an excess fraction of 11% for stillbirth and 10% for preterm birth.

Conclusion

We found an increased risk of stillbirth among women with a prior fetal death, who lifted >200 kg/day, and an exposure-response relationship between occupational lifting and preterm birth among primigravid women. The study adds to a large body of prospective studies on occupational lifting and adverse pregnancy outcomes by refined exposure assessment.

Occupational lifting of heavy loads and preterm birth: a study within the Danish National Birth Cohort

OBJECTIVES

To examine the association between occupational lifting during pregnancy and preterm birth. The risk of preterm birth was estimated for total burden lifted per day and number of medium and heavy loads lifted per day.

METHODS

In a study population of 62 803 pregnant women enrolled to the Danish National Birth Cohort from 1996 to 2002, the association between self-reported occupational lifting in the first part of pregnancy and preterm birth was analysed using logistic regression models with adjustment for age, parity, cervical cone biopsy, assisted reproduction and smoking. Associations between lifting and extremely (before 28 weeks), very (28-32 weeks) and moderately (33-37 weeks) preterm birth were analysed using Cox regression models.

RESULTS

We found a dose-response relation between total daily burden lifted and preterm birth with an OR of 1.50 (95% CI 1.03 to 2.19) with loads over 1000 kg/day. No threshold value was found. The associations were strongest for extremely and very preterm birth with HRs (95% CIs) of 4.3 (1.4 to 13.8) and 1.7 (0.7 to 4.0), respectively. Lifting heavy loads (>20 kg) more than10 times/day was associated with preterm birth up to an OR of 2.03 (95% CI 1.14 to 3.62).

CONCLUSION

In a society with social welfare and a highly regulated working environment, occupational lifting was associated with an increased risk of preterm birth.

Standardised test protocol (Constant Score) for evaluation of functionality in patients with shoulder disorders

INTRODUCTION

The Constant Score (CS), developed as a scoring system to evaluate overall functionality of patients with shoulder disorders, is widely used but has been criticised for relying on an imprecise terminology and for lack of a standardised methodology. A modified guideline was therefore published in 2008 with several new recommendations, but a standardised test protocol was not included. Also, this new version has not been translated into Danish. The aims of the present study were to develop a standardised English test protocol for the newly modified CS, and to translate and cross-culturally adapt this version into Danish.

MATERIAL AND METHODS

An English test protocol was developed and translated into Danish at two independent centres according to international recommendations. Consensus on a preliminary version was achieved. The subjective part was tested on six patients, while two physiotherapists gave feedback on the objective part. Relevant items were culturally adapted and rephrased, and a simple standardised test protocol was developed.

RESULTS

Only minor inconsistencies in the translations were found. A few questions and words had to be rephrased due to cultural and linguistic differences. One of the authors of the modified CS approved both the English and the Danish test protocol.

CONCLUSION

A simple test protocol of the modified CS was developed in both English and Danish. With precise terminology and definitions, the test protocol is the first of its kind. We suggest its use internationally for standardised assessment of the CS. Testing of validity, reliability and responsiveness of both versions needs to be done in future research.

FUNDING

not relevant.

TRIAL REGISTRATION

not relevant.