Predicting the long term course of low back pain and its consequences for sickness absence and associated work disability

The potential association of musculoskeletal pain with presenteeism and work engagement among intensive care unit nurses: a cross-sectional study

Aim: Work-related musculoskeletal disorders and associated musculoskeletal pain among intensive care nurses are important, as these factors may be related to presenteeism and work engagement. The aim of this study was to investigate the potential association of musculoskeletal pain with presenteeism and work engagement among intensive care nurses. Material and Method: This descriptive study was carried out with members of the Turkish Society of Critical Care Nurses. All the participants completed a questionnaire, which included questions about general demographic data and occupational musculoskeletal exposures (Occupational Safety and Health Administration [OSHA] Ergonomic Assessment Checklist). To measure pain, work engagement and presenteeism, the following instruments were used: The Brief Pain Inventory Short Form (BPI SF), Utrecht Work Engagement Scale (UWES-17) and Stanford Presenteeism Scale-6 (SPS-6). This study was performed in 2021, and the questionnaire was distributed via email to the database of Turkish Society of Critical Care Nurses. Results: Our study was completed with 153 intensive care unit nurses. Among the study population, 76.5% (n=117) of the nurses had chronic musculoskeletal pain, 80% of whom had exposure to lifting heavy weights. There was a weak negative correlation between pain and work engagement, as shown by the BPI SF pain interference subscale and the vigour subscale of the UWES-17 (p=0.04, r=-.166). There was also a weak negative correlation between pain and presenteeism according to the BPI SF pain interference subscale and SPS-6 (p=0.04, r=-.193). There was no statistically significant association between workplace ergonomic exposures, presenteeism, work engagement and the presence of chronic musculoskeletal pain. Conclusion: Neither chronic musculoskeletal system pain nor pain intensity was significantly correlated with work engagement, occupational musculoskeletal exposures or presenteeism. However, musculoskeletal pain-related effects on daily activities of living had a negative impact on work engagement (vigour) and presenteeism.

Work Ability and Quality of Life in Patients with Rheumatoid Arthritis

BACKGROUND

Reduced work participation has social implications (sickness absence, economic impact) and consequences for the individual patient (impoverishment, depression, limited social interaction). As patients with rheumatoid arthritis (RA) are more likely to experience job loss and/or at-work productivity loss and are at higher risk of sickness absence and, ultimately, permanent work productivity, consideration should be given to the association between work productivity or partial work capacity and quality of life (QoL). The aim of the study was to assess the relationship between QoL and the risk of work disability, as well as to estimate the risk of a future event and identify factors affecting the risk of work disability in RA inpatients.

MATERIAL AND METHODS

This cross-sectional study included 142 inpatients (65 male) aged 47 (38-58) years, who met the established criteria for a diagnosis of RA and treatment with biologic drugs. Only standardized tools were used to examine the patients: WHOQOL-BREF, MFIS and AS-WIS.

RESULTS

An analysis of the QoL scores on the WHOQOL-BREF demonstrated that the patients' QoL was lowest in the physical health domain and highest in the social relationships domain. The median WHOQOL-BREF total score in the group studied was 62.8, which indicates a moderate QoL. The median total score for the risk of work disability (AS-WIS) was 10.1, which indicates that the level of risk of work disability in the patients was higher than the average level reported in the literature. A multivariate analysis showed that the following were significant independent determinants of a higher risk of work disability: low QoL in the WHOQOL-BREF physical health (β = 0.961; p = 0.029) and psychological health (β = 1.752; p = 0.002) domains, being in a relationship (β = 0.043; p = 0.005) and the use of opioids for pain (β = 3.054; p = 0.012).

CONCLUSIONS

RA patients presented with moderate QoL, moderate fatigue (MFIS) and high risk of disability (AS-WIS). There is an association between a high risk of work disability and lower QoL, especially in the physical and psychological health domains. The lower the QoL in those domains, the higher the risk of work disability. The identification of factors increasing the risk of work disability will help in planning tailored interventions to improve at-work productivity loss and thus prevent work disability.

Reducing the burden of low back pain: results from a new microsimulation model

Background

Low back pain (LBP) causes the highest morbidity burden globally. The purpose of the present study was to project and compare the impact of three strategies for reducing the population health burden of LBP: weight loss, ergonomic interventions, and an exercise program.

Methods

We have developed a microsimulation model of LBP in Canada using a new modeling platform called SimYouLate. The initial population was derived from Cycle 1 (2001) of the Canadian Community Health Survey (CCHS). We modeled an open population 20 years of age and older. Key variables included age, sex, education, body mass index (BMI), type of work, having back problems, pain level in persons with back problems, and exercise participation. The effects of interventions on the risk of LBP were obtained from the CCHS for the effect of BMI, the Global Burden of Disease Study for occupational risks, and a published meta-analysis for the effect of exercise. All interventions lasted from 2021 to 2040. The population health impact of the interventions was calculated as a difference in years lived with disability (YLDs) between the base-case scenario and each intervention scenario, and expressed as YLDs averted per intervention unit or a proportion (%) of total LBP-related YLDs.

Results

In the base-case scenario, LBP in 2020 was responsible for 424,900 YLDs in Canada and the amount increased to 460,312 YLDs in 2040. The effects of the interventions were as follows: 27,993 (95% CI 23,373, 32,614) YLDs averted over 20 years per 0.1 unit change in log-transformed BMI (9.5% change in BMI) among individuals who were overweight and those with obesity, 19,416 (16,275, 22,557) YLDs per 1% reduction in the proportion of workers exposed to occupational risks, and 26,058 (22,455, 29,661) YLDs averted per 1% increase in the proportion of eligible patients with back problems participating in an exercise program.

Conclusions

The study provides new data on the relationship between three types of interventions and the resultant reductions in LBP burden in Canada. According to our model, each of the interventions studied could potentially result in a substantial reduction in LBP-related disability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05747-2.

Development and validation of a prediction model for unemployment and work disability among 55 950 Dutch workers

Background

This study developed prediction models for involuntary exit from paid employment through unemployment and disability benefits and examined if predictors and discriminative ability of these models differ between five common chronic diseases.

Methods

Data from workers in the Lifelines Cohort Study (n = 55 950) were enriched with monthly information on employment status from Statistics Netherlands. Potential predictors included sociodemographic factors, chronic diseases, unhealthy behaviours and working conditions. Data were analyzed using cause-specific Cox regression analyses. Models were evaluated with the C-index and the positive and negative predictive values (PPV and NPV, respectively). The developed models were externally validated using data from the Study on Transitions in Employment, Ability and Motivation.

Results

Being female, low education, depression, smoking, obesity, low development possibilities and low social support were predictors of unemployment and disability. Low meaning of work and low physical activity increased the risk for unemployment, while all chronic diseases increased the risk of disability benefits. The discriminative ability of the models of the development and validation cohort were low for unemployment (c = 0.62; c = 0.60) and disability benefits (c = 0.68; c = 0.75). After stratification for specific chronic diseases, the discriminative ability of models predicting disability benefits improved for cardiovascular disease (c = 0.81), chronic obstructive pulmonary disease (c = 0.74) and diabetes mellitus type 2 (c = 0.74). The PPV was low while the NPV was high for all models.

Conclusion

Taking workers’ particular disease into account may contribute to an improved prediction of disability benefits, yet risk factors are better examined at the population level rather than at the individual level.

Simultaneous measurement of centre of pressure and centre of mass in assessing postural sway in healthcare workers with non-specific back pain: protocol for a cross-sectional study

INTRODUCTION

Low back pain (LBP) is widely prevalent in healthcare workers. It is associated with impaired postural and core stability. So far, centre of pressure (CoP) measures have been commonly recorded through the use of a force plate in order to assess postural stability. However, this approach provides limited information about the centre of mass (CoM) movement in the lumbar region in individuals with LBP. Recent developments in sensor technology enable measurement of the trunk motion which could provide additional information on postural sway. However, the question remains as to whether CoM measures would be more sensitive in discriminating individuals with mild and moderate back pain than traditional CoP analyses. This study aims to investigate the sensitivity of CoP and CoM measures under varied stable, metastable and unstable testing conditions in healthcare workers, and their relationship with the level of subjective reported back pain.

METHODS AND ANALYSIS

This is a cross-sectional controlled laboratory study. A group of 90 healthcare professionals will be recruited from rehabilitation centres within local areas. Participants will complete the Oswestry Disability Questionnaire. The primary outcome will be the rate of their back pain on the 0-10 Low Back Pain Scale (1-3 mild pain and 4-6 moderate pain). Secondary outcomes will include variables of postural and core stability testing during bipedal and one-legged stance on a force plate, a foam mat placed on the force plate, and a spring-supported platform with either eyes open or eyes closed. Both CoP using the posturography system based on a force plate and CoM using the inertial sensor system placed on the trunk will be simultaneously measured.

ETHICS AND DISSEMINATION

Projects were approved by the ethics committee of the Faculty of Physical Education and Sport, Comenius University in Bratislava (Nos. 4/2017, 1/2020). Findings will be published in peer-reviewed journals and presented at conferences.

Occupational lower back pain and associated factors among taxi drivers in Mekelle city, north Ethiopia: a cross-sectional study

Objectives. This study aimed to assess the prevalence and associated factors of lower back pain (LBP) among taxi drivers working in Mekelle city, Tigray, Ethiopia in 2018. Methods. A community-based cross-sectional study was conducted from April to May 2018 on a sample of 294 male taxi drivers in Mekelle city, Tigray, Ethiopia. A self-administered questionnaire adapted from the Nordic musculoskeletal questionnaire was used to collect data. Independent variables that had a significant association were identified using logistic regression models. Results were reported using texts and frequency distribution tables. Results. From a total sample of 304 male drivers, 294 taxi drivers participated; hence, the response rate was 96.7%. Prevalence of self-reported LBP in the past 12 months among taxi drivers was 27.9%. Average daily hours of driving (adjusted odds ratio [AOR] 2.296, 95% confidence interval [CI] [1.194, 4.416]), using lumbar support while driving (AOR 2.075, 95% CI [1.130, 3.808]) and lack of ergonomic awareness (AOR 2.478, 95% CI [1.343, 4.575]) were significantly associated (p < 0.05) with LBP among taxi drivers. Conclusion. Prevalence of LBP in this study was more than a quarter. Average daily hours driving, use of lumbar support and ergonomics awareness were significant determinants of LBP among taxi drivers.

Evaluation of Absenteeism, Pain, and Disability in Nurses With Persistent Low Back Pain Following Cognitive Functional Therapy: A Case Series Pilot Study With 3-Year Follow-Up

OBJECTIVE

Persistent low back pain (PLBP) is a common and costly health problem worldwide. Better strategies to manage it are required. The purpose of this study was to longitudinally evaluate absenteeism, pain, and disability in nurses with PLBP following a cognitive functional therapy (CFT) intervention.

METHODS

In this case series pilot study, 33 eligible nurses with PLBP were recruited. During the baseline phase (phase A; no intervention), outcome measures were collected on 2 occasions 6 months apart (A1 and A2). During phase B, participants received an individualized CFT intervention for 14 weeks. During phase C (no intervention), outcomes were measured immediately after the intervention, as well as 3, 6, 9, 12, and 36 months after the intervention (secondary outcomes only until 12 months). LBP-related work absenteeism, pain intensity (numerical pain rating scale) and disability (Oswestry Disability Index) were the primary outcomes. Health care seeking, a range of psychological and lifestyle variables, and global perceived effect were secondary outcomes.

RESULTS

Days of absenteeism due to LBP were significantly reduced in the first and second calendar years after the CFT intervention but not the third and fourth. Disability was significantly reduced immediately after (-4.4; 95% CI = -6.5 to -2.2) and at 3 months (-4.3; 95% CI = -6.6 to -2.0), 9 months (-6.0; 95% CI = -8.1 to -3.9), and 12 months (-4.9; 95% CI = -7.0 to -2.8) after the intervention. Pain was significantly reduced immediately after (-1.2; 95% CI = -1.7 to -0.8) and at 3 months (-1.5; 95% CI = -2.0 to -0.9), 9 months (-1.1; 95% CI = -1.9 to -0.3), and 12 months (-0.9; 95% CI = -1.5 to -0.2) after the intervention. Total health care seeking (consults and proportion of participants) was significantly reduced after the intervention. All psychosocial variables, except for 1, demonstrated significant improvements at all follow-up assessments.

CONCLUSIONS

This case series pilot study demonstrated significant reductions in LBP-related absenteeism, pain intensity, disability, health care seeking, and several psychological and lifestyle behaviors until the 1-year follow-up among nurses with PLBP following an individualized CFT intervention. Further evaluation of the efficacy of CFT in high-quality randomized clinical trials among nurses is recommended.

Working conditions as risk factors for early exit from work-in a cohort of 2351 employees in Germany

Objectives

We would assess the possible impact of a range of physical and psychosocial working conditions on early exit from paid employment (i.e., before retirement age) in a representative employee population in Germany.

Methods

We analysed a cohort from the German Study on Mental Health at Work (S-MGA) with a baseline of 2351 employees in 2011/12, sampled randomly from the register of integrated employment biographies (IEB) at the Institute for Employment Research (IAB). Follow-up ended mid-2015. Early Exit comprised episodes of either pensioning, long-term sickness absence or unemployment ≥ 18 months. Total follow-up years were 8.422. Working conditions were partly assessed by the Copenhagen Psychosocial Questionnaire (COPSOQ). Through Cox regressions, associations of baseline working conditions with time to event of exit were estimated—adjusting for baseline age, gender, poverty, fixed-term contract and socioeconomic position.

Results

In multiple regressions, awkward body postures (HR = 1.24; 95% CI = 1.07–1.44), heavy lifting (1.17; 1.00–1.37) and high work pace (1.41; 1.16–1.72) were associated with exit. The estimated attributable fraction of exit for being exposed to less than optimal work environment was 25%. Regarding specific exit routes, repetitive movements (1.25; 1.03–1.53) increased the risk for the long-term sickness absence; work pace (1.86; 1.22–2.86) and role clarity (0.55; 0.31–1.00) were associated to unemployment; and control over working time (0.72; 0.56–0.95) decreased the risk of the early retirement.

Conclusions

Work environment seems to be important for subsequent early exit from work. Physical and psychosocial demands seem to be associated to exit to a stronger extent than resources at work.

Recurrent pain and work disability: a record linkage study

Purpose

We examined the associations between recurrent single- and multisite pain and incident sickness absence (SA) of different lengths and the risk of disability pension (DP).

Methods

The data were derived from the Finnish Helsinki Health Study. Pain measures were recorded for panel 1 in 2000/2 and 2007, and for panel 2 in 2007 and 2012 (altogether 3191 employees). SA data were obtained from the employer’s personnel register and DP events from the Finnish Centre for Pensions. Negative binomial regression models with generalized estimation equations were used to model the incidence of self-certified short- (1–3 days), and medically certified medium- (4–14 days) and long-term (more than 14 days) SA episodes. Cox regression models were fitted for the associations between pain and all-cause DP and competing risk models for DP by diagnostic groups. Social and health-related covariates were adjusted for.

Results

Recurrent pain was associated with short-, medium- and long-term SA. Additionally, recurrent single- and multisite pain increased the risk of long-term SA. Recurrent single or multisite pain was further associated with an increased risk of DP, while a single instance of pain did not increase the risk.

Conclusions

These results suggest that recurrent pain is a robust determinant of subsequent SA and DP risk. Improved understanding of determinants of recurrent pain is needed to inform the development of targeted measures to reduce SA and premature exit from employment.

Electronic supplementary material

The online version of this article (10.1007/s00420-019-01494-5) contains supplementary material, which is available to authorized users.

Impact of a Safe Resident Handling Program in Nursing Homes on Return-to-Work and Re-injury Outcomes Following Work Injury

Purpose This study examined the impact of a Safe Resident Handling Program (SRHP) on length of disability and re-injury, following work-related injuries of nursing home workers. Resident handling-related injuries and back injuries were of particular interest. Methods A large national nursing home corporation introduced a SRHP followed by three years of training for 136 centers. Lost-time workers' compensation claims (3 years pre-SRHP and 6 years post-SRHP) were evaluated. For each claim, length of first episode of disability and recurrence of disabling injury were evaluated over time. Differences were assessed using Chi square analyses and a generalized linear model, and "avoided" costs were projected. Results The SRHP had no impact on length of disability, but did appear to significantly reduce the rate of recurrence among resident handling-related injuries. As indemnity and medical costs were three times higher for claimants with recurrent disabling injuries, the SRHP resulted in significant "avoided" costs due to "avoided" recurrence. Conclusions In addition to reducing overall injury rates, SRHPs appear to improve long-term return-to-work success by reducing the rate of recurrent disabling injuries resulting in work disability. In this study, the impact was sustained over years, even after a formal training and implementation program ended. Since back pain is inherently a recurrent condition, results suggest that SRHPs help workers remain at work and return-to-work.

Within-individual analysis of pain and sickness absence among employees from low and high occupational classes: a record linkage study

OBJECTIVES

Pain is linked to an increased risk of sickness absence (SA); however, the extent to which unmeasured time-invariant differences explain this association is yet unknown. Therefore, we determined the within-individual associations between pain and short-term (in the survey year) and long-term (2 years following the survey years) SA risk in high and low occupational classes while controlling for the potential bias due to unobservable time-invariant characteristics.

METHODS

The Helsinki Health Study data consisting of midlife public sector employees with mailed surveys from up to four time points, and SA record linkage were used (3983 persons). The within-individual estimates were calculated using hybrid negative binomial regression models.

RESULTS

Acute/subacute pain was associated with a 13% increase in the rate of short-term SA days (incidence rate ratio 1.13 [95% CI 1.01 to 1.27]), while the association was somewhat stronger for chronic pain (1.32 [1.19-1.47]). For the employees in the low occupational class, these associations were robust (1.29 [1.10-1.50] for acute/subacute and 1.43 [1.23-1.66] for chronic pain), whereas only chronic pain was associated with SA among those in the high occupational class (1.25 [1.08-1.46]). Chronic pain was also associated with SA days in the long term without occupational class differences. Similar results were obtained for multisite pain (pain in several locations).

CONCLUSIONS

These results indicate that particularly chronic and multisite pain have a within-individual link to SA but ignoring unobservable differences between those reporting pain and those not might yield overstated effect sizes. Pain might have a different relation to SA in low and high occupational classes.

Distress and worry as mediators in the relationship between psychosocial risks and upper body musculoskeletal complaints in highly automated manufacturing

As a result of changes in manufacturing including an upward trend in automation and the advent of the fourth industrial revolution, the requirement for supervisory monitoring and consequently, cognitive demand has increased in automated manufacturing. The incidence of musculoskeletal disorders has also increased in the manufacturing sector. A model was developed based on survey data to test if distress and worry mediate the relationship between psychosocial factors (job control, cognitive demand, social isolation and skill discretion), stress states and symptoms of upper body musculoskeletal disorders in highly automated manufacturing companies (n = 235). These constructs facilitated the development of a statistically significant model (RMSEA 0.057, TLI 0.924, CFI 0.935). Cognitive demand was shown to be related to higher distress in employees, and distress to a higher incidence of self-reported shoulder and lower back symptoms. The mediation model incorporating stress states (distress, worry) as mediators is a novel approach in linking psychosocial risks to musculoskeletal disorders. Practitioners' Summary With little requirement for physical work in many modern automated manufacturing workplaces, there is often minimal management focus on Work-Related Musculoskeletal Disorders (WRMSDs) as important occupational health problems. Our model provides evidence that psychosocial factors are important risk factors in symptoms of WRMSD and should be managed.

Prevalence and factors associated with low back pain among nurses at a regional hospital in KwaZulu-Natal, South Africa

Background

Low back pain (LBP) is a public health problem worldwide and is a common cause of work-related disorder among workers, especially in the nursing profession. Recruitment and retention of nurses is a challenge, and the nursing shortage has been exacerbated by the burden of occupational injuries such as LBP and related disabilities. The physiotherapy clinical records revealed that caseload of nurses presenting for the management of LBP was increasing. The prevalence and factors associated with LBP were unclear.

Methods

A cross-sectional study design with an analytic component was implemented. Data were collected utilising a self-administered questionnaire to determine the prevalence and factors associated with LBP among nurses at a regional hospital. Bivariate analyses were performed to determine the factors associated with LBP.

Results

The point prevalence of current LBP in nurses was 59%. The highest prevalence was recorded among enrolled nurses (54%), respondents aged 30–39 (46%), overweight respondents (58%) and those working in obstetrics and gynaecology (49%). Bending (p = 0.002), prolonged position (p = 0.03) and transferring patients (p = 0.004) were strongly associated with LBP. Nurses with more than 20 years in the profession reported a high prevalence of LBP. The prevalence of LBP was higher among the participants who were on six-month rotations (76%) compared with those on yearly rotation (16%).

Conclusion

A high proportion of nurses reported to have LBP. Occupational factors are strongly associated with LBP. Education programmes on prevention and workplace interventions are required in order to reduce occupational injuries.

Electromyographic activity of the erector spinae: The short-effect of one workday for welders with nonspecific chronic low back pain, an observational study

OBJECTIVE

This study aimed to evaluate the effect of one workday on pain and perceived exertion, muscular strength, and electromyographic activity of the erector spinae muscles in welders with and without low back pain. This is an observational cohort study.

PARTICIPANTS

Twenty-two welders, metallurgical shipbuilding, were equally divided into 2 groups: low back pain and no low back pain. Pain and perceived exertion. Muscular strength by maximal voluntary contractions and electromyographic activity of right and left erector spinae muscles during maximal voluntary contractions and in the 3 welding positions for 2 periods of the workday (in the morning and at the end of the workday).

RESULTS

At the end of workday, the pain increased significantly for the low back pain group (t(22) = 2.448; P= 0.023). The perceived exertion also increased significantly for both groups at the end of workday groups (F(1,22) = 8.570, P= 0.000) and periods (F(1,22) = 8.142, P= 0.000). There were no significant differences between groups and workday periods for muscular strength and electromyographic activity during maximal voluntary contractions of the erector spinae. There was no significance difference for electromyographic activity between groups and workday period and in the 3 welding positions.

CONCLUSION

Although the pain and perceived exertion increased at the end of the workday, these results did not interfere in muscular strength and electromyographic activity of right and left erector spinae muscles. Thus, we can conclude that welders with chronic low back pain had a good physical capacity (muscular strength) and that muscle performance was maintained.

Cultural adaptation, reliability and validity of Japanese Orthopaedic Association Back Pain Evaluation Questionnaire to Brazilian Portuguese

OBJECTIVE

To describe the translation and cultural adaptation of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire into Brazilian Portuguese, and verifies the reliability and validity of this new version.

METHODS

A cross-cultural adaptation of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire was performed using the following steps: translation, back-translation, committee review, and pre-testing phase (50 subjects). The psychometric properties were evaluated by application of the questionnaire to 102 patients. Reliability was assessed by homogeneity and stability of measures. The criterion-related validity was tested by comparing scores of Japanese Orthopaedic Association Back Pain Evaluation Questionnaire to Oswestry and Medical Outcomes Study 36 - Item Short questionnaires.

RESULTS

Excellent internal consistency was found in both test (Cronbach's α of 0.90) and re-test (Cronbach's α of 0.91). The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire showed good reliability and the correlations ranged from reasonable (0.64) to very good (r=0.91).

CONCLUSION

The Brazilian Portuguese version of Medical Outcomes Study 36 - Item Short was easy to apply and understand. The questionnaire had a great impact on assessment and multidimensional care of patients with low back pain.

The contribution from psychological, social, and organizational work factors to risk of disability retirement: a systematic review with meta-analyses

BACKGROUND

Previous studies indicate that psychological, social, and organizational factors at work contribute to health, motivation, absence from work, and functional ability. The objective of the study was to assess the current state of knowledge of the contribution of psychological, social, and organizational factors to disability retirement by a systematic review and meta-analyses.

METHODS

Data sources: A systematic literature search for studies of retirement due to disability in Medline, Embase, and PsychINFO was performed. Reference lists of relevant articles were hand-searched for additional studies.

DATA EXTRACTION

Internal validity was assessed independently by two referees with a detailed checklist for sources of bias. Conclusions were drawn based on studies with acceptable quality.

DATA SYNTHESIS

We calculated combined effect estimates by means of averaged associations (Risk ratios) across samples, weighting observed associations by the study's sample size. Thirty-nine studies of accepted quality were found, 37 of which from the Nordic countries.

RESULTS

There was moderate evidence for the role of low control (supported by weighted average RR = 1.40; 95% CI = 1.21-1.61) and moderate evidence for the combination of high demands and low control (although weighted average was RR = 1.45; 95% CI = 0.96-2.19) as predictors of disability retirement. There were no major systematic differences in findings between the highest rated and the lowest rated studies that passed the criterion for adequate quality. There was limited evidence for downsizing, organizational change, lack of employee development and supplementary training, repetitive work tasks, effort-reward imbalance to increase risk of disability pension. Very limited evidence was found for job demands, evening or night work, and low social support from ones superior.

CONCLUSIONS

Psychological and organizational factors at work contribute to disability retirement with the most robust evidence for the role of work control. We recommend the measurement of specific exposure factors in future studies.

Towards exposure limits for working postures and musculoskeletal symptoms - a prospective cohort study

Occupational postures are considered to be an important group of risk factors for musculoskeletal pain. However, the exposure-outcome association is not clear yet. Therefore, we aimed to determine the exposure-outcome association of working postures and musculoskeletal symptoms. Also, we aimed to establish exposure limits for working postures. In a prospective cohort study among 789 workers, intensity, frequency and duration of postures were assessed at baseline using observations. Musculoskeletal pain was assessed cross-sectionally and longitudinally and associations of postures and pain were addressed using logistic regression analyses. Cut-off points were estimated based on ROC-curve analyses. Associations were found for kneeling/crouching and low-back pain, neck flexion and rotation and neck pain, trunk flexion and low-back pain, and arm elevation and neck and shoulder pain. The results provide insight into exposure-outcome relations between working postures and musculoskeletal symptoms as well as evidence-based working posture exposure limits that can be used in future guidelines and risk assessment tools. Practitioner Summary: Our study gives insight into exposure-outcome associations of working postures and musculoskeletal symptoms (kneeling/crouching and low-back pain, neck flexion/rotation and neck pain, trunk flexion and low-back pain, and arm elevation and neck and shoulder pain). Results furthermore deliver evidence-based postural exposure limits that can be used in guidelines and risk assessments.

Recurrence of sickness absence episodes certified by general practitioners in the UK

BACKGROUND

Compared to other areas of sickness certification, recurrence of certified sickness absence has been relatively under-researched.

OBJECTIVES

This study aims to report the extent and patterns of recurrence and to identify factors associated with higher rates of recurrence.

METHODS

Sickness certification ('fit note') data were collected from 68 general practices in eight regions of the UK for 12 months.

RESULTS

Twenty percent of 31,453 patients in the study had a recurrent certified sickness episode, with over half of these having the second episode in the same diagnostic category as their first. Mental health problems accounted for over a half of all days certified in same-diagnosis recurrent episodes. Male gender, residing in an area of social deprivation, a longer episode of initial certified sickness absence, not having return to work ('may be fit') advice in the first episode, having a mental disorder or musculoskeletal (particularly back) problem were all independently associated with a higher incidence of recurrence.

CONCLUSION

Differential risk of recurrence needs to be considered when designing return-to-work interventions. Evaluation of effectiveness of interventions (particularly for sickness absentees with mental health problems) has to consider the sustainability of employment after a return to work.

Detailed assessment of low-back loads may not be worth the effort: A comparison of two methods for exposure-outcome assessment of low-back pain

The trade-off between feasibility and accuracy of measurements of physical exposure at the workplace has often been discussed, but is unsufficiently understood. We therefore explored the effect of two low-back loading measurement tools with different accuracies on exposure estimates and their associations with low-back pain (LBP). Low-back moments of 93 workers were obtained using two methods: a moderately accurate observation-based method and a relatively more accurate video-analysis method. Group-based exposure metrics were assigned to a total of 1131 workers who reported on their LBP status during three follow-up years. The two methods were compared regarding individual and group-based moments and their predictive value for LBP. Differences between the two methods for peak moments were high at the individual level and remained substantial at group level. For cumulative moments, differences between the two methods were attenuated as random inaccuracies cancelled out. Peak moments were not predictive for LBP in any method while cumulative moments were, suggesting comparable predictive values of the two methods. While assessment of low-back load improves from investing in collecting relatively more accurate individual-based data, this does not necessarily lead to better predictive values on a group level, especially not for cumulative loads.

Associations of work-related factors and work engagement with mental and physical health: a 1-year follow-up study among older workers

PURPOSE

The goals of this study were to determine whether, among older employees, unfavourable physical and psychosocial work-related factors were associated with poorer mental and physical health and whether high work engagement buffered the associations between unfavourable work-related factors and poorer health.

METHODS

A 1-year longitudinal study with employed persons aged 45-64 was conducted within the Study on Transitions in Employment, Ability and Motivation (n = 8,837). Using an online questionnaire, work-related factors (physical: physical load; psychosocial: psychological job demands, autonomy, and support) and work engagement were measured at baseline and health at baseline and 1-year follow-up. General linear models were used to assess associations of work-related factors and work engagement with health. Tests of interaction terms assessed whether work engagement buffered the work-related factor-health associations.

RESULTS

Unfavourable psychosocial work-related factors at baseline were associated with poorer mental health at follow-up. Higher physical load, higher psychological job demands, and lower autonomy at baseline were associated with poorer physical health at follow-up. Higher work engagement at baseline was related to better physical and especially better mental health during the 1-year follow-up. Work engagement had a small effect on the associations between work-related factors and health.

CONCLUSIONS

Among older employees, especially the promotion of a high work engagement and, to a lesser extent, favourable work-related factors can be beneficial for mental health in particular.

Bias and power in group-based epidemiologic studies of low-back pain exposure and outcome--effects of study size and exposure measurement efforts

OBJECTIVES

Exposure-outcome studies, for instance on work-related low-back pain (LBP), often classify workers into groups for which exposures are estimated from measurements on a sample of workers within or outside the specific study. The present study investigated the influence on bias and power in exposure-outcome associations of the sizes of the total study population and the sample used to estimate exposures.

METHODS

At baseline, lifting, trunk flexion, and trunk rotation were observed for 371 of 1131 workers allocated to 19 a-priori defined occupational groups. LBP (dichotomous) was reported by all workers during 3 years of follow-up. All three exposures were associated with LBP in this parent study (P < 0.01). All 21 combinations of n = 10, 20, 30 workers per group with an outcome, and k = 1, 2, 3, 5, 10, 15, 20 workers actually being observed were investigated using bootstrapping, repeating each combination 10000 times. Odds ratios (OR) with P values were determined for each of these virtual studies. Average OR and statistical power (P < 0.05 and P < 0.01) was determined from the bootstrap distributions at each (n, k) combination.

RESULTS

For lifting and flexed trunk, studies including n ≥ 20 workers, with k ≥ 5 observed, led to an almost unbiased OR and a power >0.80 (P level = 0.05). A similar performance required n ≥ 30 workers for rotated trunk. Small numbers of observed workers (k) resulted in biased OR, while power was, in general, more sensitive to the total number of workers (n).

CONCLUSIONS

In epidemiologic studies using a group-based exposure assessment strategy, statistical performance may be sufficient if outcome is obtained from a reasonably large number of workers, even if exposure is estimated from only few workers per group.

Does rare use of assistive devices during patient handling increase the risk of low back pain? A prospective cohort study among female healthcare workers

PURPOSE

To investigate whether rare use of assistive devices during patient handling increases the respective risk for infrequent and frequent low back pain (LBP) among female healthcare workers reporting to be free of LBP at baseline.

METHOD

Female healthcare workers replied to questionnaires about use of assistive devices during patient handling activities (rarely, occasionally and often) and LBP in both 2005 and 2006. Among those reporting to be free of LBP (0 days the past 12 months) in 2005 (n = 1,478), the multi-adjusted odds ratio for developing infrequent LBP (1-30 days the past 12 months) and frequent LBP (>30 days the past 12 months) in 2006 depending on use of assistive devices was prospectively investigated.

RESULTS

The multi-adjusted odds ratio for developing infrequent LBP was 1.21 (95 % CI 0.90-1.62) for those occasionally using assistive devices, and 1.78 (95 % CI 1.19-2.66) for those rarely using assistive devices, referencing healthcare workers often using assistive devices during patient handling (p < 0.01 for trend). No associations between use of assistive devices during patient handling and risk of frequent LBP were found.

CONCLUSION

The study indicates that rare use of assistive devices can increase the risk for developing infrequent LBP in female healthcare workers reporting to be free from LBP at baseline.

Trunk muscles strength as a risk factor for nonspecific low back pain: a pilot study

OBJECTIVE

To investigate the effects of asymptomatic back muscle weakness and spinal deformity on low back pain (LBP).

METHODS

Sixty healthy subjects without LBP participated in this study. Radiography and an isokinetic/isometric dynamometer were used to respectively measure spinal scoliosis/lordosis and the strength of the trunk flexors/extensors. After 2 years, 48 subjects visited the hospital again and LBP episodes, its severity and the Korean version of the Oswestry Disability Index were assessed. Differences between the group with LBP and the group without LBP were evaluated and the association with LBP incidence and severity was determined.

RESULTS

Sex, age, and trunk strength were significantly different in both group. Sex and age were significantly positive associated with LBP incidence. The isometric trunk flexor and extensor strength, maximum isokinetic trunk flexor and extensor strength were significantly and negatively associated with the LBP severity. The maximum isokinetic trunk extensor and maximum isometric trunk extensor strength was significantly negative associated with the LBP incidence.

CONCLUSION

LBP incidence is associated with isometric and isokinetic trunk extensor weakness, whereas LBP severity is associated with age, sex, isokinetic trunk extensor and flexor weakness, isometric trunk extensor and flexor weakness.

Prevention of low back pain and its consequences among nurses' aides in elderly care: a stepped-wedge multi-faceted cluster-randomized controlled trial

BACKGROUND

A high prevalence of low back pain has persisted over the years despite extensive primary prevention initiatives among nurses' aides. Many single-faceted interventions addressing just one aspect of low back pain have been carried out at workplaces, but with low success rate. This may be due to the multi-factorial origin of low back pain. Participatory ergonomics, cognitive behavioral training and physical training have previously shown promising effects on prevention and rehabilitation of low back pain. Therefore, the main aim of this study is to examine whether a multi-faceted workplace intervention consisting of participatory ergonomics, physical training and cognitive behavioral training can prevent low back pain and its consequences among nurses' aides. External resources for the participating workplace and a strong commitment from the management and the organization support the intervention.

METHODS/DESIGN

To overcome implementation barriers within usual randomized controlled trial designed workplace interventions, this study uses a stepped-wedge cluster-randomized controlled trial design with 4 groups. The intervention is delivered to the groups at random along four successive time periods three months apart. The intervention lasts three months and integrates participatory ergonomics, physical training and cognitive behavioral training tailored to the target group. Local physiotherapists and occupational therapists conduct the intervention after having received standardized training. Primary outcomes are low back pain and its consequences measured monthly by text messages up to three months after initiation of the intervention.

DISCUSSION

Intervention effectiveness trials for preventing low back pain and its consequences in workplaces with physically demanding work are few, primarily single-faceted, with strict adherence to a traditional randomized controlled trial design that may hamper implementation and compliance, and have mostly been unsuccessful. By using a stepped wedge design, and obtain high management commitment and support we intend to improve implementation and aim to establish the effectiveness of a multi-faceted intervention to prevent low back pain. This study will potentially provide knowledge of prevention of low back pain and its consequences among nurses' aides. Results are expected to be published in 2015-2016.

TRIAL REGISTRATION

The study is registered as ISRCTN78113519.

Data processing costs for three posture assessment methods

Background

Data processing contributes a non-trivial proportion to total research costs, but documentation of these costs is rare. This paper employed a priori cost tracking for three posture assessment methods (self-report, observation of video, and inclinometry), developed a model describing the fixed and variable cost components, and simulated additional study scenarios to demonstrate the utility of the model.

Methods

Trunk and shoulder postures of aircraft baggage handlers were assessed for 80 working days using all three methods. A model was developed to estimate data processing phase costs, including fixed and variable components related to study planning and administration, custom software development, training of analysts, and processing time.

Results

Observation of video was the most costly data processing method with total cost of € 30,630, and was 1.2-fold more costly than inclinometry (€ 26,255), and 2.5-fold more costly than self-reported data (€ 12,491). Simulated scenarios showed altering design strategy could substantially impact processing costs. This was shown for both fixed parameters, such as software development and training costs, and variable parameters, such as the number of work-shift files processed, as well as the sampling frequency for video observation. When data collection and data processing costs were combined, the cost difference between video and inclinometer methods was reduced to 7%; simulated data showed this difference could be diminished and, even, reversed at larger study sample sizes. Self-report remained substantially less costly under all design strategies, but produced alternate exposure metrics.

Conclusions

These findings build on the previously published data collection phase cost model by reporting costs for post-collection data processing of the same data set. Together, these models permit empirically based study planning and identification of cost-efficient study designs.

Employment consequences of depressive symptoms and work demands individually and combined

BACKGROUND

Denmark, like other Western countries, is recently burdened by increasingly high social spending on employment consequences caused by ill mental health. This might be the result of high work demands affecting persons with ill mental health. Therefore, this study assesses to what extent depressive symptoms and high work demands, individually and combined, have an effect on employment consequences.

METHODS

We conducted a population-based 7-year longitudinal follow-up study with baseline information from the year 2000 on socio-demographics, lifestyle, depressive symptoms and work demands. In total, 5785 employed persons, aged 40 and 50 years, were included. Information about employment status, sick leave and work disability was obtained from registers. Logistic regression models were used to measure separate and combined effects of depressive symptoms and work demands on job change, unemployment and sick leave during 2001-02 and work disability during 2003-07.

RESULTS

After adjustment for covariates, high physical work demands and depressive symptoms had a graded effect on subsequent unemployment, sick leave and permanent work disability. Persons with both depressive symptoms and high physical demands had the highest risks, especially for sick leave, but the combined effect did not exceed the product of single effects. Persons who perceived high amount of work changed job significantly more frequently.

CONCLUSION

Persons with depressive symptoms might have an increased risk of negative employment consequences irrespective of the kind and amount of work demands. This might be an effect on the level of work ability in general as well as partly the result of health selection and co-morbidity.

Prevalence and work-related risk factors for reduced activities and absenteeism due to low back symptoms

Although quite a lot is known about the risk factors for low back symptoms (LBS), less is known about the risk factors for the consequences of LBS. A sample of 3003 men and women randomly selected from the New Zealand Electoral Roll, were interviewed by telephone about self reported physical, psychosocial, organizational, environmental factors and the consequences of LBS (i.e. self-reported reduced activities and absenteeism). The 12-month period prevalence of reduced activities and absenteeism were 18% and 9%, respectively. Lifting (OR 1.79 95% CI 1.16-2.77) increased the risk of reduced activities. Working in awkward/tiring positions (OR 2.11 95% CI 1.20-3.70) and in a cold/damp environment (OR 2.18 95% CI 1.11-4.28) increased the risk of absenteeism. Among those with LBS, reduced activities increased with working in a hot/warm environment (OR 2.14 95% CI 1.22-3.76) and absenteeism was increased with work in awkward/tiring positions (OR 2.06 95% CI 1.13-3.77), tight deadlines (OR 1.89 95% CI 1.02-3.50), and a hot/warm environment (OR 3.35 95% CI 1.68-6.68). Interventions to reduce the consequences of LBS should aim to reduce awkward/tiring positions, lifting and work in a cold/damp environment. For individuals with LBS, additional focus should be to reduce tight deadlines, and work in hot/warm environments.

Does occupational lifting and carrying among female health care workers contribute to an escalation of pain-day frequency?

BACKGROUND

The aim of the study was to investigate if different frequencies, loads and trunk postures of occupational lifting and carrying increases the risk of sub-chronic (1-30 days last 12 months) low back pain (LBP) to become persistent (>30 days last 12 months) among female health care workers.

METHODS

Female health care workers answered a questionnaire about occupational lifting or carrying frequency (rarely, occasionally and frequently), load (low: 1-7 kg, moderate: 8-30 kg and heavy: >30 kg) and trunk posture (upright or forward bent back), and days with LBP in 2005 and 2006.

RESULTS

The odds ratio (OR) for developing persistent LBP in 2006 from these characteristics of occupational lifting and carrying was investigated with multi-adjusted logistic regressions among female health care workers with sub-chronic LBP (n = 2381) in 2005. Among health care workers with sub-chronic LBP, increased risk of persistent LBP was found from frequently lifting or carrying with forward bent back of moderate loads (OR: 1.63; 95% CI: 1.15-2.33) and heavy loads (OR: 1.56; 95% CI: 1.04-2.34). No increased risk for LBP to develop into a persistent condition was found for frequent lifting with upright back, frequent lifting or carrying of light loads, or occasionally lifting or carrying of any loads.

CONCLUSIONS

Preventive initiatives for sub-chronic LBP to develop into a persistent condition ought to focus on reducing frequent lifting and carrying of moderate and heavy loads with forward bent back.

Prevalence and risk factors for low back pain in industrial workers

OBJECTIVES

The aim of the present study was to determine the prevalence of low back pain (LBP) in industrial workers, check for possible LBP related risk factors and investigate the associations between physical activity and severity of low back pain.

METHODS

We conducted a cross-sectional study among 430 workers of an industrial company over the previous 12 months. The industrial workers were given questionnaires and assigned to two groups: (1) with low back pain, (2) without low back pain. Group 1 was then divided into three subgroups according to the answer to question (a) LBP without irradiation, called mild cases, (b) LBP with irradiation above the knee, called moderate cases, LBP with the irradiation below the knee, called severe cases.

RESULTS

LBP was found in 61.6% of workers. The prevalence of LBP was significantly associated with physical activity (p = 0.03). There was a significant difference between frequent physical activity and severity of LBP (p = 0.01). Work-related physical factors showed strong associations with LBP. The main risk factors for low back pain among production workers were extreme trunk flexion (OR = 3.5, 95% CI 1.7-7.3), as well as lifting of loads (OR = 3.5, 95% CI 1.9-6.2), pushing or pulling heavy loads (OR = 3.5, 95% CI 1.9-6.2) and exposure to whole body vibration (OR = 1.7, 95% CI 1.0 -3.0).

CONCLUSION

Daily life conditions, job-related factors are associated with the occurrence of low back pain. These results suggest that individuals with LBP should avoid nonspecific physical activities to reduce pain and improve psychological health.

Low back pain predict sickness absence among power plant workers

Background:

Low back pain (LBP) remains the predominant occupational health problem in most industrialized countries and low-income countries. Both work characteristics and individual factors have been identified as risk factors. More knowledge about the predictors of sickness absence from LBP in the industry will be valuable in determining strategies for prevention.

Objectives:

The aim of this longitudinal study was to investigate whether individual, work-related physical risk factors were involved in the occurrence of LBP sickness absence.

Methods:

A follow-up study was conducted among 489 workers, aged 18–65 years, at Kosovo Energetic Corporation in Kosovo. This cross-sectional study used a self-administered questionnaire to collect data on individual and work-related risk factors and the occurrence of LBP sickness absence. Logistic regression models were used to determine associations between risk factors and the occurrence of sickness absence due to LBP.

Results:

Individual factors did not influence sickness absence, whereas work-related physical factors showed strong associations with sickness absence. The main risk factors for sickness absence due to LBP among production workers were extreme trunk flexion (OR = 1.71, 95% CI = 1.05–2.78) as well as very extreme trunk flexion (OR = 6.04, 95% CI = 1.12–32.49) and exposure to whole-body vibration (OR = 1.75, 95% CI = 1.04–2.95).

Conclusion:

Reducing sickness absence from LBP among power plant workers requires focusing on the working conditions of blue-collar workers and risk factors for LBP. Increasing social support in the work environment may have effects in reducing sickness absence from LBP.

Physical activity and low back pain: a systematic review of recent literature

The objective of the study is to systematically evaluate the available evidence on the association between physical activity (i.e. occupational load and non-occupational physical activities) and low back pain (LBP). A systematic approach was used to explore the literature between 1999 and 2009. Studies were selected for inclusion following a comprehensive search of Medline, Embase and CINAHL. The methodological quality of each study was assessed. Studies were considered to be of 'high quality' if they met the cut-off criterion of 60% of the maximum available quality score. Thirty-six cohort or case-control studies were retrieved. Heavy workload and the accumulation of loads or frequency of lifts were moderate to strong risk factors for LBP. Strong associations were found for flexed, rotated and the awkward positions of the lumbar spine. Inconsistent results were found for leisure time physical activities, sports and physical exercise. Studies focusing on daily habitual physical activities (e.g. domestic activities and commuting) in association with LBP are lacking. In conclusion, the occurrence of LBP is related to the nature and intensity of the physical activities undertaken. However, physical activities can be subdivided into separate types and intensities and the ultimate physical load is the sum of all these activities. This makes it difficult to designate one particular activity as the cause of LBP.

Biopsychosocial factors and perceived disability in saleswomen with concurrent low back pain

Objectives

To quantify disability level in salespeople with concurrent low back pain (LBP) and to determine the relative associations between demographic, occupational, psychosocial and clinical factors and back disability. LBP is the most common cause of work-related disability in people under 45 years of age and the most expensive cause of work-related disability, in terms of workers' compensation and medical expenses. Evidence suggests high prevalence of LBP in salespeople.

Methods

A cross-sectional survey was conducted in which 184 saleswomen with a current episode of self-reported LBP working in a large up-scale department store filled out a battery of 6 self-administered questionnaires and received a standardised physical examination.

Results

Saleswomen with concurrent LBP had low disability levels. Factors significantly associated with disability were pain intensity, measured by a visual analogue scale, in the past week (p < 0.001), physical and mental health status (p < 0.001, p = 0.003, respectively), fear avoidance scores for both work and physical activities (p = 0.031, p = 0.014, respectively), past history of LBP (p = 0.019), and self-reported frequency of pushing or pulling objects placed in high positions during work (p = 0.047). A significant level (45%) of the variance in disability status was explained by these variables.

Conclusion

In clinical management of LBP workers who required prolonged standing, such as salespeople, clinicians should look for modifiable risk factors associated with disability. Specific measures need to be taken to prevent disability due to LBP among salespeople.

Causal assessment of occupational carrying and low back pain: results of a systematic review

BACKGROUND CONTEXT

Occupational low back pain (LBP) is a common musculoskeletal disorder that results in high healthcare use and a heavy societal burden from morbidity and medical costs. The etiology of LBP is unclear, although numerous physical activities in the workplace have been implicated in its development. Determining the causal relationship between LBP and specific occupational activities requires a rigorous methodological approach.

PURPOSE

To conduct a systematic review of the scientific literature focused on establishing a causal relationship between occupational carrying and LBP.

STUDY DESIGN

Systematic review of the literature was performed.

SAMPLE

Studies reporting an association between occupational carrying and LBP.

OUTCOME MEASURES

Numerical association between different levels of exposure to occupational carrying and the presence or severity of LBP.

METHODS

A systematic review was performed to identify, evaluate, and summarize the literature related to establishing a causal relationship between occupational carrying and LBP by using the commonly used Bradford-Hill framework. The literature was searched using Medline, Embase, CINAHL, Cochrane Library, the Occupational Safety and Health (OSH-ROM) database, gray literature (eg, studies not published in peer-reviewed journals), hand-searching occupational health journals, reference lists of included studies, and content experts. Study quality was evaluated using a modified version of the Newcastle-Ottawa Scale. Levels of evidence supporting specific Bradford-Hill criteria were evaluated for different categories of carrying and types of LBP outcomes.

RESULTS

This search yielded 2,766 citations. A total of nine high-quality studies reported on occupational carrying and LBP, including four case-control studies and five prospective cohort studies. These nine studies reported strong and consistent evidence against a statistical association between carrying and LBP. Three studies assessed dose-response, of which only one reported a dose-response trend that was not statistically significant. Five studies were able to assess temporality, but none reported results fulfilling this aspect of causality. The biological plausibility of carrying and LBP was not discussed in any of the nine studies. None of these studies attempted to evaluate the experiment criterion by devising studies in which the exposure to carrying and level of LBP could be measured before and after implementing a strategy aimed at reducing carrying in the workplace to determine its effect on LBP.

CONCLUSIONS

This review failed to identify high-quality studies that supported any of the Bradford-Hill criteria to establish causality between occupational carrying and LBP. Based on these results, it is unlikely that occupational carrying is independently causative of LBP in the populations of workers studied.

Recurrence of medically certified sickness absence according to diagnosis: a sickness absence register study

INTRODUCTION

Sickness absence is a major public health problem. Research on sickness absence focuses on interventions aimed at expediting return to work. However, we need to know more about sustaining employees at work after return to work. Therefore, this study investigated the recurrence of sickness absence according to diagnosis.

METHODS

We analyzed the registered sickness absence data of 137,172 employees working for the Dutch Post and Telecom. Episodes of sickness absence were medically certified, according to the ICD-10 classification of diseases, by an occupational physician. The incidence density (ID) and recurrence density (RD) of medically certified absences were calculated per 1,000 person-years in each ICD-10 category.

RESULTS

Sickness absence due to musculoskeletal disorders had the highest recurrence (RD = 118.7 per 1,000 person-years), followed by recurrence of sickness absence due to mental disorders (RD = 80.4 per 1,000 person-years). The median time to recurrent sickness absence due to musculoskeletal disorders was 409 days after the index episode. Recurrences of sickness absence due to musculoskeletal disorders accounted for 37% of the total number of recurrent sickness absence days. For recurrences of sickness absence due to mental disorders this was 328 days and 21%, respectively. Unskilled employees with a short duration (<5 years) of employment had a higher risk of recurrent sickness absence.

CONCLUSIONS

Interventions to expedite return to work of employees sick-listed due to musculoskeletal or mental disorders should also aim at reducing recurrence of sickness absence in order to sustain employees at work.

Musculoskeletal impairments in the Norwegian working population: the prognostic role of diagnoses and socioeconomic status: a prospective study of sickness absence and transition to disability pension

STUDY DESIGN

Population-based, 5-year prospective cohort study.

OBJECTIVE

To assess the incidence of musculoskeletal disorders (MSDs) in sickness absence longer than 8 weeks in Norway, and to identify diagnostic and socioeconomic predictors of the transition to disability pension (DP).

SUMMARY OF BACKGROUND DATA

MSDs are prevalent and of major concern for sickness absence. Previous epidemiological studies are largely cross-sectional and based on self-reports, often with low response rates, selection, and reporting bias. Prospective studies with physician-verified diagnoses might be a better approach.

METHODS

Thirty-seven thousand nine hundred forty-two females and 26,307 males with an episode of sickness absence >8 weeks in 1997, certified with a MSD were followed up for 5 years. Diagnostic and sociodemographic data were obtained from a national database. Cases were divided into 9 diagnostic subgroups, based on the International Classification of Primary Health Care. Survival analysis was performed with granting of DP as the endpoint, in the full sample and for diagnostic subgroups.

RESULTS

Over all 20% of cases obtained DP during follow-up. Among those aged 50 to 62 and among those with only basic education 46% obtained DP. DP rates were highest for osteoarthrosis (47%), rheumatoid arthritis (46%), and myalgia/fibromyalgia (38%). Fractures/injuries had the lowest rate. Controlled for age, education and income, relative risk of DP was 1.5 (95% CI: 1.4-1.6) for upper limb problems, 2.0 (95% CI: 1.8-2.1) for back problems, 2.8 (95% CI: 2.5-3.1) for osteoarthrosis, 3.3 (95% CI: 3.0-3.6) for myalgia/fibromyalgia, and 4.2 (95% CI: 3.9-4.7) for rheumatoid arthritis, compared to "fractures and injuries."

CONCLUSION

Age, diagnoses, and socioeconomic variables were important predictors of an adverse outcome among workers with a sickness absence of 8 or more weeks. Further research is needed to determine whether differentiated follow-up strategies might prevent permanent disability.

Quantifying relationships between selected work-related risk factors and back pain: a systematic review of objective biomechanical measures and cost-related health outcomes

The objective of this investigation was to use published literature to demonstrate that specific changes in workplace biomechanical exposure levels can predict reductions in back injuries. A systematic literature review was conducted to identify epidemiologic studies which could be used to quantify relationships between several well-recognized biomechanical measures of back stress and economically relevant outcome measures. Eighteen publications, describing 15 research studies, which fulfilled search criteria were found. Quantitative associations were observed between back injuries and measures of spinal compression, lifting, lifting ratios, postures, and combinations thereof. Results were intended to provide safety practitioners with information that could be applied to their own work situations to estimate costs and benefits of ergonomic intervention strategies before they are implemented.

A prospective study of the effectiveness of early intervention with high-risk back-injured workers--a pilot study

INTRODUCTION

It was postulated that workers, at the sub-acute stage after injury, respond differently to clinical and occupational interventions offered in a workers' compensation environment. Individual worker risk of disability, it was further believed, would influence the effectiveness of early intervention. The objective of the current pilot study was to evaluate return to work (RTW) outcomes following proactive, combined clinical, occupational and case management-based interdisciplinary early intervention, provided in a workers' compensation environment 4-10 weeks of onset of back pain, to workers with medium and high risk for disability.

METHODS

The project was a controlled study comparing conventional workers' compensation case management with integrated, interdisciplinary and multimodal early intervention (hereinafter referred to as "EI"). At baseline, risk status was determined by a validated Risk for Disability Questionnaire by Carragee et al. (Spine 5(1):24-35, 2005). Seventeen workers at high risk of protracted disability and 20 workers at moderate risk of disability received conventional case management, and 17 workers assessed at high risk of protracted disability and 18 workers at moderate risk of disability received the Early Intervention.

RESULTS

At 3 months post back pain onset, no statistically significant differences were identified in RTW outcomes between conventional case management and the Early Intervention. However, by 6 months post back pain onset, workers at high risk of work disability who received the Early Intervention were significantly more likely to RTW than high risk workers who received conventional case management. In contrast, moderate risk workers continued to exhibit no statistically significant differences in RTW outcomes.

CONCLUSION

Multimodal Early Intervention in the workers' compensation case management context is likely effective for workers with sub-acute back pain who are at high risk of occupational disability. The comprehensive Early Intervention is, however, likely redundant for workers who are not at high risk for disability and should not be applied indiscriminately. Further studies are required to determine longer-term Early Intervention outcomes, and to replicate the findings using a randomized control design. Also, with a larger sample size, it will be possible to determine predictors of occupational outcomes.

Is a history of work-related low back injury associated with prevalent low back pain and depression in the general population?

Background

Little is known about the role of prior occupational low back injury in future episodes of low back pain and disability in the general population. We conducted a study to determine if a lifetime history of work-related low back injury is associated with prevalent severity-graded low back pain, depressive symptoms, or both, in the general population.

Methods

We used data from the Saskatchewan Health and Back Pain Survey – a population-based cross-sectional survey mailed to a random, stratified sample of 2,184 Saskatchewan adults 20 to 69 years of age in 1995. Information on the main independent variable was gathered by asking respondents whether they had ever injured their low back at work. Our outcomes, the 6-month period prevalence of severity-graded low back pain and depressive symptoms during the past week, were measured with valid and reliable questionnaires. The associations between prior work-related low back injury and our outcomes were estimated through multinomial and binary multivariable logistic regression with adjustment for age, gender, and other important covariates.

Results

Fifty-five percent of the eligible population participated. Of the 1,086 participants who responded to the question about the main independent variable, 38.0% reported a history of work-related low back injury. A history of work-related low back injury was positively associated with low intensity/low disability low back pain (OR, 3.66; 95%CI, 2.48–5.42), with high intensity/low disability low back pain (OR, 4.03; 95%CI, 2.41–6.76), and with high disability low back pain (OR, 6.76; 95%CI, 3.80–12.01). No association was found between a history of work-related low back injury and depression (OR, 0.85; 95%CI, 0.55–1.30).

Conclusion

Our analysis shows an association between past occupational low back injury and increasing severity of prevalent low back pain, but not depression. These results suggest that past work-related low back injury may be an important risk factor for future episodes of low back pain and disability in the general population.