High physical work load and low job satisfaction increase the risk of sickness absence due to low back pain: results of a prospective cohort study

Objective: To determine whether physical and psychosocial load at work influence sickness absence due to low back pain.

Methods: The research was a part of the study on musculoskeletal disorders, absenteeism, stress, and health (SMASH), a 3 year prospective cohort study on risk factors for musculoskeletal disorders. Workers from 21 companies located throughout The Netherlands participated in the part of this study on sickness absence due to low back pain. The study population consisted of 732 workers with no sickness absences of 3 days or longer due to low back pain in the 3 months before the baseline survey and complete data on the reasons for absences during the follow up period. The mean (range) period of follow up in this group was 37 (7–44) months. Physical load at work was assessed by analyses of video recordings. Baseline information on psychosocial work characteristics was obtained by a questionnaire. Data on sickness absence were collected from company records. The main outcome measure was the rate of sickness absences of 3 days or longer due to low back pain during the follow up period.

Results: After adjustment of the work related physical and psychosocial factors for each other and for other potential determinants, significant rate ratios ranging from 2.0 to 3.2 were found for trunk flexion, trunk rotation, lifting, and low job satisfaction. A dose-response relation was found for trunk flexion, but not for trunk rotation or lifting. Non-significant rate ratios of about 1.4 were found for low supervisor support and low coworker support. Quantitative job demands, conflicting demands, decision authority, and skill discretion showed no relation with sickness absence due to low back pain.

Conclusions: Flexion and rotation of the trunk, lifting, and low job satisfaction are risk factors for sickness absence due to low back pain. Some indications of a relation between low social support, either from supervisors or coworkers, and sickness absence due to low back pain are also present.

     

Prognostic factors related to recurrent low-back pain and sickness absence

OBJECTIVES: This study aimed at determining the prognostic factors related to the recurrence of low-back pain and future sickness absence due to low-back pain. METHODS: Data were used from a prospective cohort study in a working population with a 3-year follow-up period. They were collected with annual questionnaires. A generalized estimating equation model was used to study the relation between pain characteristics, individual characteristics, and work-related factors and the recurrence of low-back pain or sickness absence due to low-back pain in the following year. Adjustments were made for potential confounders. RESULTS: All the pain characteristics [odds ratios (OR) varying from 1.4 to 2.4], flexion and rotation of the upper part of the body [OR 1.6, 95% confidence interval (95% CI) 1.1-2.5], low decision authority (OR 1.6, 95% CI 1.0-2.6), and low job satisfaction (OR 1.5, 95% CI 1.0-2.3), increased the risk of recurrent low-back pain. High disability due to low-back pain (OR 2.6, 95% CI 1.2-5.7), low co-worker support (OR 4.1, 95% CI 1.6-10.5), and low job satisfaction (OR 2.4, 95% CI 1.3-4.5) were predictors of sickness absence due to low-back pain. Lifting weights did not influence the risk of recurrences or sick leave. CONCLUSIONS: According to this study, high disability due to low-back pain is a prognostic factor for recurrent low-back pain and future sickness absence due to low-back pain. In addition, the following work-related factors predict a poor prognosis of low-back pain: flexion or rotation of the trunk, low job satisfaction, low decision authority, and low social support.     

Psychosocial work characteristics and psychological strain in relation to low-back pain

OBJECTIVES: This study investigated the relationship between psychosocial work characteristics and low-back pain and the potential intermediate role of psychological strain variables in this relationship. METHODS: The research was part of a prospective cohort study of risk factors for musculoskeletal symptoms. The study population consisted of 861 workers from 34 companies in The Netherlands who had no low-back pain at baseline and for whom data on the occurrence of low-back pain were obtained with annual questionnaires during a 3-year follow-up period. Information on psychosocial work characteristics and psychological strain variables was collected using a questionnaire at baseline. Cases of low-back pain were defined as workers who reported, in at least one of the annual follow-up questionnaires, that they had had regular or prolonged low-back pain in the previous 12 months. RESULTS: After adjustment for individual factors and quantified physical load at work, nonsignificant relative risks ranging from 1.3 to 1.6 were observed for high quantitative job demands, high conflicting demands, low supervisory support, and low co-worker support. Decision authority and skill discretion showed no relationship with low-back pain. In general, the estimated relative risks for the psychosocial work characteristics were scarcely influenced by additional adjustment for job satisfaction, emotional exhaustion, and sleeping difficulties. CONCLUSIONS: It can be concluded that low social support, from either supervisors or co-workers, appears to be a risk factor for low-back pain. Some indications of a relationship between high quantitative job demands and high conflicting demands and low-back pain were also found. Little evidence was found for an intermediate role for the psychological strain variables under study.     

Risk factors for first-ever low back pain among workers in their first employment

BACKGROUND: Low back pain has been estimated to be the most costly ailment of people of working age. Both work characteristics and individual factors have been identified as risk factors. The first interaction between work characteristics and individual factors occurs when workers start in their first job. AIMS: To investigate work-related risk factors for first-ever low back pain in young workers in their first employment. METHODS: A cross-sectional analysis was performed on 278 young workers in their first employment and without a history of low back pain prior to working. Work-related physical factors, psychosocial work characteristics, individual variables and first-ever low back pain were queried by means of a questionnaire. RESULTS: About half of the workers who developed low back pain after job start did so in the first year of employment. An increased risk was observed for (i) long periods of seated work [relative risk (RR) = 3.2, 95% confidence interval (CI) = 1.6-6.4]; (ii) more than 12 flexion or rotation movements of the trunk per hour (RR = 3.0, 95%CI = 1.4-6.4); and (iii) more than 3 years seniority in a job involving lifting more than 25 kg at least once an hour (RR = 3.7, 95%CI = 1.4-9.4). As to psychosocial work characteristics, first-ever low back pain was associated with a combination of low psychological job demands and low supervisor support. CONCLUSION: Work-related physical factors and psychosocial work characteristics should be considered as risk factors for first-ever low back pain. First-ever episodes of low back pain are common in the first year of employment. This may reflect a lack of work experience or training.     

Prospective study of physical and psychosocial risk factors for sickness absence

AIM: To investigate the associations between psychosocial and physical work environment exposures and sickness absence from work taking into account health, health behaviour and employer characteristics known to affect sickness absence. METHODS: In 1995, a random sample of 5574 employees aged 18-64 years were interviewed. In 2000, 3792 of those still employed supplied data on days absent from work the year preceding the date of follow-up. Associations between risk factors at baseline and sickness absence at follow-up were studied. Logistic regression analyses were performed. RESULTS: Sickness absence was associated with working with arms lifted/hands twisted, extreme bending/stooping of the back/neck, repetitive monotonous work, low skill discretion, low decision authority, obesity, current and former smoking, poor self-rated health, female gender, increasing age and public employer. The aetiological fraction attributable to differences in work environment exposures was calculated to be 40%. CONCLUSION: The study suggests a potential for reducing sickness absence through multifactorial interventions towards smoking, obesity, physical and psychosocial work environment exposures. The study showed that differences in work environment exposures account for 40% of the cases of high sickness absence.     

Different risk factors for musculoskeletal complaints and musculoskeletal sickness absence

OBJECTIVES: The aim of this study was to investigate whether individual, work-related physical and psychosocial risk factors involved in the occurrence of musculoskeletal complaints also determine musculoskeletal sickness absence. METHODS: This cross-sectional study used a self-administered questionnaire to collect data on individual and work-related risk factors and the occurrence of musculoskeletal complaints and musculoskeletal sickness absence among 373 employees of laundry-works and dry-cleaning establishments (response rate 87%). Logistic regression models were used to determine associations between risk factors and the occurrence of musculoskeletal complaints and sickness absence due to these complaints. RESULTS: Both work-related physical and psychosocial factors showed strong associations with low-back pain and upper-extremity complaints. Work-related physical factors did not influence sickness absence, whereas psychosocial factors showed some associations with sickness absence. Sickness absence was associated with The Netherlands as the country of birth [odds ratio (OR) 0.3, 95% confidence interval (95% CI) 0.2-0.6], and female workers had an episode of sickness absence due to low-back pain less often (OR 0.5, 95% CI 0.3-0.9), but more often due to upper-extremity complaints (OR 2.2, 95% CI 1.14.5). CONCLUSIONS: Work-related physical and psychosocial factors largely determine the occurrence of low-back pain and upper-extremity complaints, whereas individual factors predominantly determine whether persons with these musculoskeletal complaints take sick leave.     

Psychosocial work environment and registered absence from work: estimating the etiologic fraction

BACKGROUND: Evidence is growing that an adverse psychosocial work environment increases sickness absence, but little is known on the magnitude of this problem or the impact of specific factors. METHODS: Psychological demands, decision authority, skill discretion, social support from colleagues or supervisor, predictability, and meaning of work were assessed with questionnaires at baseline and sickness absence was followed-up in employers' registers for 1,919 respondents (response rate 75.2%, 68% women, mainly low-skilled jobs) from 52 Danish workplaces during a 2-year period. Etiologic fractions (EFs) were calculated with the most favorable quartiles as reference. RESULTS: In the fully adjusted model, the following EFs were found: decision authority: 12%; social support from supervisors: 8%; psychological demands: 6%; and predictability: 5%. In total, the seven psychosocial factors explained 29% of all sick-leave days. CONCLUSIONS: The results suggest that improving the psychosocial work environment among the less favorable 75% may prevent substantial amounts of absence.     

Work-related psychosocial factors and chronic pain: a prospective cohort study in Canadian workers

OBJECTIVE: The purpose of this study was to determine whether organizational and psychosocial aspects of work experience affect the risk of chronic pain conditions. METHODS: We used longitudinal data from the National Population Health Survey in Canada (n = 6571). The data were analyzed using the Cox model. RESULTS: Work-related stress was a risk factor for developing chronic pain or discomfort. The relative risk was 1.39 (95% CI = 1.01-1.91) for medium stress and 1.80 (95% CI = 1.28-2.52) for high stress. High psychological demands and low skill discretion were independently associated with pain/discomfort. There was no association between psychosocial factors at work and physician-diagnosed chronic back problems, arthritis, or migraine headaches. CONCLUSIONS: Work-related stress is a significant risk factor for nonspecific complaints of pain or discomfort among workers.     

Workplace levels of psychosocial factors as prospective predictors of registered sickness absence

OBJECTIVE: We sought to investigate whether workplace levels of psychosocial work environment factors predict individual sickness absence. METHODS: Data were collected in a prospective study in 52 Danish workplaces in three organizations: municipal care, technical services, and a pharmaceutical company. Psychosocial factors were aggregated as workplace means. We used multilevel Poisson regression models with psychosocial factors as predictors and individual level sickness absence from absence registries as outcome. RESULTS: High workplace levels of decision authority predicted low sickness absence in the technical services (rate ratio = 0.66, 95% confidence interval = 0.51-0.86) and high workplace levels of skill discretion predicted low sickness absence in the pharmaceutical company (rate ratio = 0.74, 95% confidence interval = 0.62-0.88) after control for relevant confounders. Workplaces in municipal care did not differ with respect to the psychosocial factors. CONCLUSIONS: Psychosocial factors at the workplace level may be important predictors of sickness absence.     

Psychosocial risk factors for neck pain: a systematic review

BACKGROUND: Neck pain, which is assumed to be a multifactorial disease, is a major problem in modern society. METHODS: To identify the most important psychosocial risk factors for neck pain, a systematic review of the literature was carried out. The methodological quality of all studies in the review was assessed. Four levels of evidence were defined to assess the strength of evidence for potential risk factors for neck pain (strong, moderate, some or inconclusive evidence). RESULTS: Some evidence was found for a positive relationship between neck pain and high quantitative job demands, low social (coworker) support, low job control, high and low skill discretion and low job satisfaction. Inconclusive evidence was found for high job strain, low supervisor support, conflicts at work, low job security, and limited rest break opportunities. CONCLUSIONS: The procedure of the assessment of the methodological quality and the rating system applied to distinguish between high- and low-score studies, had a considerable influence on the level of evidence, indicating that changes in this procedure may have a major impact on the overall conclusions of this review.     

Risk factors for musculoskeletal disorders among nursing personnel in Greek hospitals

OBJECTIVES: To investigate the relationships between physical, psychosocial, and individual characteristics and different endpoints of musculoskeletal complaints of the lower back, neck and shoulders. METHODS: In this cross-sectional study a questionnaire survey was carried out among 351 nursing personnel (response 84%) in six general hospitals in Athens, Greece. A questionnaire was used on physical and psychosocial workload, need for recovery, perceived general health and (1) the occurrence of musculoskeletal complaints in the past 12 months, (2) chronic complaints during at least 3 months, and (3) complaints which led to sickness absence. In logistic regression analysis odds ratios (ORs) were estimated for all relevant risk factors. RESULTS: Self-reported factors of physical load were associated with the occurrence of back pain (OR=1.85), neck pain (OR=1.88), and shoulder pain (OR=1.87) but these factors were not associated with chronic complaints and musculoskeletal sickness absence. Physical load showed a trend with the number of musculoskeletal complaints with ORs of 2.47 and 4.13 for two and three musculoskeletal complaints, respectively. No consistent influence of psychosocial factors on complaints, chronicity, or sickness absence was observed. A perceived moderate general health was also a risk factor, and strongest associations were observed for sickness absence due to back pain (OR=2.03), neck pain (OR=8.31), and shoulder pain (OR=6.84). CONCLUSIONS: The handling of physical loads among nurses seems to put them at risk for the occurrence of musculoskeletal disorders. The development of these complaints into chronic complaints and associated sickness absence is strongly determined by perceived general health and almost not associated with work-related physical and psychosocial risk factors. When the influence of work-related risk factors on musculoskeletal health is being investigated, the general health status of individual workers should be taken into account.     

Experimental manipulation of psychosocial exposure and questionnaire sensitivity in a simulated manufacturing setting

Purpose  The objectives of this study were to determine the efficacy of experimental manipulations of psychosocial exposures and to evaluate the sensitivity of a psychosocial questionnaire by determining the factors perceived. Methods  A 50-item questionnaire was developed from the job content questionnaire (JCQ) and the quality of worklife survey (QWL). The experiment involved simulated work at different physical and psychosocial levels. Forty-eight participants were exposed to two levels of one psychosocial manipulation (job control, job demands, social support, or time pressure). Results  Significantly different questionnaire responses supported the effectiveness of psychosocial manipulations. Exploratory factor analysis revealed five factors: skill discretion and decision authority, stress level and supervisor support, physical demands, quality of coworker support, and decision-making support. Conclusions  These results suggest that psychosocial factors can be manipulated experimentally, and that questionnaires can distinguish perceptions of these factors. These questionnaires may be used to assess perceptions of psychosocial factors in experimental settings.     

Does high income buffer the association between adverse working conditions and ill health?

AIM: A study was undertaken to analyse the possible interaction between work environment and income for the probability of self-rated health being less than good. METHODS: Data from the Swedish Survey of Living Conditions for the years 1998 and 1999 were analysed. Employed 20- to 64-year-olds with a registered wage were included (n=5982). The synergy index (SI) was applied, using odds ratios from logistic regressions for men, women, and all. Low and high levels of physical demands, decision authority, skill discretion and psychological demands were separately combined with low- and high-wage income (median split). Full-time work and four sociodemographic factors were controlled for. RESULTS: Significant synergy was found for women when they were exposed to low income and a low level of skill discretion (SI=1.46 [1.01-2.13]), although this was attenuated by education level (SI=1.47 [0.96-2.25]). In general (both sexes), poor health caused by low income and unfavourable work is additive rather than multiplicatively exaggerating the risk among the jointly exposed. CONCLUSION: Work exposures in the form of high physical load, low levels of decision authority and skill discretion, or a high level of psychological demands were significantly related to poor health also when income was high, suggesting that high income does not seem to buffer the detrimental effects of adverse working conditions. As nearly half of employed women were found to be in circumstances marked by synergy, it seems a relevant public health issue to improve these women's conditions at work, by simultaneously increasing, for example, job variety and wages.     

Organisational downsizing and musculoskeletal problems in employees: a prospective study

OBJECTIVES—To study the association between organisational downsizing and subsequent musculoskeletal problems in employees and to determine the association with changes in psychosocial and behavioural risk factors.
METHODS—Participants were 764 municipal employees working in Raisio, Finland before and after an organisational downsizing carried out between 1991 and 1993. The outcome measures were self reports of severity and sites of musculoskeletal pain at the end of 1993 and medically certified musculoskeletal sickness absence for 1993-5. The contribution of changes in psychosocial work characteristics and health related behaviour between the 1990 and 1993 surveys was assessed by adjustment.
RESULTS—After adjustment for age, sex, and income, the odds ratio (OR) for severe musculoskeletal pain between major and minor downsizing and the corresponding rate ratios for musculoskeletal sickness absence were 2.59 (95% confidence interval (95% CI) 1.5 to 4.5) and 5.50 (3.6 to 7.6), respectively. Differences between the mean number of sites of pain after major and minor downsizing was 0.99 (0.4 to 1.6). The largest contribution from changes in work characteristics and health related behaviour to the association between downsizing and musculoskeletal problems was from increases in physical demands, particularly in women and low income employees. Additional contributory factors were reduction of skill discretion (relative to musculoskeletal pain) and job insecurity. The results were little different when analyses were confined to initially healthy participants.
CONCLUSIONS—Downsizing is a risk factor for musculoskeletal problems among those who remain in employment. Much of this risk is attributable to increased physical demands, but adverse changes in other psychosocial factors may also play a part.


Keywords: ocupational health; musculoskeletal disorders; downsizing     

Psychosocial work environment predictors of short and long spells of registered sickness absence during a 2-year follow up

OBJECTIVE: The objective of this study was to investigate the impact of psychosocial work environment factors on short and long absence spells. METHODS: Questionnaire data on work environment exposures and registered absence data during 2-year follow up were analyzed with Poisson regression for 1919 employees from the private and public sector. RESULTS: Short spells (1-10 working days) were predicted by low supervisor support, low predictability, and low meaning at work among men and high skill discretion among women. Long spells (>10 days) were predicted by low decision authority, low supervisor support, and low predictability among men and high psychologic demands and low decision authority among women. The variables predictability and meaning at work were developed for this study. CONCLUSION: Specific psychosocial work environment factors have both common and different effects on short and long absence spells. Effects also differ by gender.     

Psychosocial factors and work related sickness absence among permanent and non-permanent employees

STUDY OBJECTIVE: To examine the association between psychosocial work factors and work related sickness absence among permanent and non-permanent employees by sex. DESIGN: A cross sectional survey conducted in 2000 of a representative sample of the European Union total active population, aged 15 years and older. The independent variables were psychological job demands and job control as measures of psychosocial work environment, and work related sickness absence as the main outcome. Poisson regression models were used to compute sickness absence days' rate ratios. SETTING: 15 countries of the European Union. PARTICIPANTS: A sample of permanent (n = 12 875) and non-permanent (n = 1203) workers from the Third European Survey on Working Conditions. RESULTS: High psychological job demands, low job control, and high strain and passive work were associated with higher work related sickness absence. The risks were more pronounced in non-permanent compared with permanent employees and men compared with women. CONCLUSIONS: This work extends previous research on employment contracts and sickness absence, suggesting different effects depending on psychosocial working conditions and sex.     

Work relatedness of chronic neck pain with physical findings--a systematic review

OBJECTIVES: This paper systematically reviews the work-relatedness of neck-shoulder disorders with associated physical findings. METHODS: Studies incorporating a physical examination were focused upon. Four detailed reviews were searched, and a systematic search of the MEDLINE, Embase BIDS, and Psychinfo databases was conducted until May 2006, the key words for the outcome and various occupational exposures being combined. The quality of each paper was rated by criteria related to study design, power, sampling methods, response rate, potential for bias, or confounding, and approaches to the assessment of exposure outcome. Weight was given to studies with objective exposure-response information. RESULTS: Twenty-one relevant reports (four prospective) were found. Most considered the outcome neck pain with palpation tenderness (tension neck syndrome) or mixed neck-shoulder disorder (predominantly tension neck syndrome). Most investigations shared common limitations--small sample size, potential for confounding, incomplete blinding, and crude exposure assessment. The overall quality of the information was rated as excellent for only two reports. Exposures included repetitive work (14 studies), static loading (12 studies), neck flexion (7 studies), force (5 studies), and occupational psychosocial factors (7 studies). Moderate evidence was found for a causal relation for repetition at the shoulder and for neck flexion allied with repetition. Limited evidence was found for hand-wrist repetition, neck flexion with respect to static loading and force in the absence of repetition, and high job demands, low control, low job support and job strain. CONCLUSION: There is some evidence that neck pain with palpation tenderness is causally related to workplace exposures. However, evidence is lacking on the validity, clinical course, and functional importance of this diagnostic entity.     

Are neck flexion,neck rotation,and sitting at work risk factors for neck pain? Results of a prospective cohort study

OBJECTIVE—To study the relation between neck pain and work related neck flexion, neck rotation, and sitting.
METHODS—A prospective cohort study was performed with a follow up of 3 years among 1334 workers from 34 companies. Work related physical load was assessed by analysing objectively measured exposure data (video recordings) of neck flexion, neck rotation, and sitting posture. Neck pain was assessed by a questionnaire. Adjustments were made for various physical factors that were related or not related to work, psychosocial factors, and individual characteristics.
RESULTS—A significant positive relation was found between the percentage of the working time in a sitting position and neck pain, implying an increased risk of neck pain for workers who were sitting for more than 95% of the working time (crude relative risk (RR) 2.01, 95% confidence interval (95% CI) 1.04 to 3.88; adjusted RR 2.34, 95% CI 1.05 to 5.21). A trend for a positive relation between neck flexion and neck pain was found, suggesting an increased risk of neck pain for people working with the neck at a minimum of 20° of flexion for more than 70% of the working time (crude RR 2.01, 95% CI 0.98 to 4.11; adjusted RR 1.63, 95% CI 0.70 to 3.82). No clear relation was found between neck rotation and neck pain.
CONCLUSION—Sitting at work for more than 95% of the working time seems to be a risk factor for neck pain and there is a trend for a positive relation between neck flexion and neck pain. No clear relation was found between neck rotation and neck pain.


Keywords: neck pain; physical risk factors; longitudinal cohort study     

Biomechanical and psychosocial risk factors for low back pain at work.

OBJECTIVES: This study determined whether the physical and psychosocial demands of work are associated with low back pain. METHODS: A case-control approach was used. Case subjects (n = 137) reported a new episode of low back pain to their employer, a large automobile manufacturing complex. Control subjects were randomly selected from the study base as cases accrued (n = 179) or were matched to cases by exact job (n = 65). Individual, clinical, and psychosocial variables were assessed by interview. Physical demands were assessed with direct workplace measurements of subjects at their usual jobs. The analysis used multiple logistic regression adjusted for individual characteristics. RESULTS: Self-reported risk factors included a physically demanding job, a poor workplace social environment, inconsistency between job and education level, better job satisfaction, and better coworker support. Low job control showed a borderline association. Physical-measure risk factors included peak lumbar shear force, peak load handled, and cumulative lumbar disc compression. Low body mass index and prior low back pain compensation claims were the only significant individual characteristics. CONCLUSIONS: This study identified specific physical and psychosocial demands of work as independent risk factors for low back pain.     

Job demands, health perception and sickness absence

BACKGROUND: Investigation of the relations between job demands, health and sickness absence is required to design a strategy for the prevention of absence and disability. AIM: To study the relationships between (physical and psychological) job demands, health perception and sickness absence. METHODS: Prospective study of 414 male employees working in two organizations with low company absence levels. Job demands and health were examined using the Basic Occupational Health Questionnaire. Sickness absence was followed for 1 year thereafter. The number of days and episodes of absence were counted. RESULTS: The questionnaires of 247 workers (60%) were suitable for statistical analysis. Physical job demands (r = 0.41; P <0.01) and, to a lesser extent, psychological job demands (r = 0.16; P = 0.01) were related to the number of health complaints. Short (1-7 days) duration absence was neither related to job demands nor to the number of health complaints. Longer (>7 days) duration absence was positively related to psychological job demands and to the number of health complaints. CONCLUSIONS: Job demands, particularly physical demands, correlated with perceived health. Poor health predicted long-term sickness absence. Early recognition of poor health should be the basis of a strategy that prevents long-term sickness absence.