Ola Leijon

Validity of a self-administered questionnaire for assessing physical work loads in a general population.

Learning ObjectivesDescribe the design and rationale for this study evaluating eight questions on perceived physical load that are commonly a part of public health questionnaires.Recount the findings on validity of the eight physical-load questions, and the implications for which questions may be retained and which should be redesigned.Explain whether and how these findings were influenced by gender, type of work, and the presence of musculoskeletal complaints. The aim of the study was to evaluate eight questions concerning physical loads, used in public health questionnaires. Working women and men (203) completed a self-administered questionnaire twice, following a test-retest method. The questions were also validated with a structured interview. Response agreement was calculated with Cohen’s &kgr; statistics with quadratic weights (&kgr;w). Test-retest agreement varied from 0.74 to 0.92, and inter-method agreement from 0.38 to 0.81. The lowest coefficients were for the questions concerning bent/twisted work postures (&kgr;w 0.38) and repetitive movements (&kgr;w 0.39). The results did not indicate any substantial influence of gender, type of work or musculoskeletal complaint. The questions concerning general physical activity and sitting work postures, and physical exercise/sports during leisure times, had good validity. The questions concerning bent/twisted work posture and repetitive movements need to be re-designed.

Multilevel analyses of organizational change and working conditions in public and private sector

The aim was to investigate organizational impact on working conditions and to explore the associations between sector, different types of organizational change, and working conditions. A strategic selection was made of representative staff members from 72 work sites. Data pertaining to organizational factors were collected from managers, and to working conditions from employees. Multilevel analyses were performed, with 10 aspects of self-reported and expert assessed psychosocial and ergonomic/physical working conditions as the dependent variables, and patterns of organizational change and sector as the explanatory variables. The results showed that the variance in working conditions was significantly attributed to organizational level (16 – 65% of the variance), and that both the pattern of change and the sector were important. Organizations that had not undergone change provided the best work conditions. The “standardizing” and “market-adjusting” patterns of change had deleterious effects, while the “lean” and “centralizing” patterns led to dual outcomes. Organizational change was perceived as having more negative consequences in the public sector than in the private sector. The results indicate that organizational change contributes to increased differentiation of working conditions, as different types of changes congregate in specific areas of the labour market and affect groups of employees differently.

Educational differences in disability pension among Swedish middle-aged men: role of factors in late adolescence and work characteristics in adulthood

Background The association between level of education and disability pension (DP) is well known. Earlier studies have investigated the importance of early life factors and work characteristics but not in combination. The aim of this study was to investigate the association between level of education and DP among Swedish middle-aged working men and to what extent such an association can be explained by factors measured in late adolescence and work characteristics in adulthood. Methods Information about IQ, health-related lifestyle factors, psychiatric and musculoskeletal diagnoses was obtained from the 1969 conscription cohort, consisting of 49 321 Swedish men. Data collected when subjects were 18–20 years of age were combined with national register-based information about level of education, job control and physical strain at work in adulthood, and information about DP between 1991 and 2002. Results There was a strong graded association between level of education and DP. Those with the lowest level of education had a four times greater probability of having DP as compared with those with the highest level. In multivariable analyses, factors measured in late adolescence, IQ in particular, attenuated the association more than work-related characteristics in adulthood. Conclusions The authors found an association between level of education and DP among Swedish middle-aged working men. A large part of the association was explained by factors measured in late adolescence, IQ in particular, and somewhat less by work characteristics measured in adulthood. Level of education remained as a significant predictor of DP in middle age after full adjustment.

Prevalence of self-reported neck-shoulder-arm pain and concurrent low back pain or psychological distress: time-trends in a general population, 1990-2006.

Study Design. Analysis of repeated cross-sectional surveys. Objective. To investigate the prevalence of neck-shoulder-arm pain and concurrent low back pain and psychological distress in a geographical area over a 16-year period. Summary of Background Data. A large number of studies have shown that nonspecific neck, shoulder, and arm pain is a very common symptom in the general population. However, few studies have followed the prevalence of neck-shoulder-arm pain within a geographical area, in order to investigate time-trends. Methods. This study provides an analysis of questionnaire data collected every 4 years between 1990 and 2006 on the prevalence of neck-shoulder-arm pain and concurrent low back pain or psychological distress in the County of Stockholm, Sweden (response rate: 61%–69%). All individuals aged 21 to 64 years (n = 1976–26,611) were included in the study. Results. Over the 16-year period, the prevalence of self-reported neck-shoulder-arm pain rose slightly, from 22.8% to 25.0% among females (prevalence rate ratio [PRR]: 1.10) and from 12.8% to 15.4% among males (PRR: 1.21). The prevalence of neck-shoulder-arm pain with concurrent low back pain also rose slightly, from 8.4% to 10.8% among females (PRR: 1.28) and from 5.3% to 6.6% among males (PRR: 1.24). In contrast, the prevalence of neck-shoulder-arm pain with concurrent psychological distress rose more substantially, from 4.4% to 8.5% among females (PRR: 1.91) and from 2.0% to 4.3% among males (PRR: 2.18). All prevalence rates rose between 1990 and 2002, and decreased in 2006 compared to 2002. The gender gap in prevalence did not change over time. Conclusion. Although the prevalence of neck-shoulder-arm pain and concurrent symptoms decreased in 2006 compared to 2002, it is still too early to conclude that we have reached and passed the peak of the “epidemic” of neck-shoulder-arm pain.

Prevalence of low back pain and concurrent psychological distress over a 16-year period

Objectives: To investigate time trends of low back pain (LBP) and concurrent psychological distress in the general population. Methods: Every 4 years between 1990 and 2006, a self-administered questionnaire including the General Health Questionnaire (GHQ-12) and a question on LBP were sent to a random sample of the population in the county of Stockholm (response rate 61–69%). All individuals aged 21–64 years in the five samples (n = 1976–26 611) were included in the study. Results: Among women, the prevalence of self-reported LBP rose rather moderately during the 16-year period, from 12.5% to 16.4% (prevalence rate ratio (PRR) 1.31; 95% CI 1.11 to 1.55). The prevalence did not change at all among men (PRR 1.02; 95% CI 0.85 to 1.23). In contrast, the prevalence of LBP with concurrent psychological distress rose more substantially, from 2.6% to 5.9% among women (PRR 2.23; 95% CI 1.53 to 3.24) and from 1.9% to 3.5% among men (PRR 1.82; 95% CI 1.14 to 2.90). The prevalence of both LBP and LBP with concurrent psychological distress seemed to fluctuate somewhat over the period. Conclusions: Between 1990 and 2006, the focus of discussion of the high societal costs for sickness absence and disability pensions gradually shifted from musculoskeletal disorders to psychological well-being. As a result, the general population’s awareness and perception of pain and psychological distress may have changed and, in turn, affected individuals’ willingness to report these symptoms. Further research is necessary to investigate the impact of cultural changes on subjective symptom reporting.

Work and health among immigrants and native Swedes 1990–2008: a register-based study on hospitalization for common potentially work-related disorders, disability pension and mortality

BackgroundThere are many immigrants in the Swedish workforce, but knowledge of their general and work-related health is limited. The aim of this register-based study was to explore whether documented migrant residents in Sweden have a different health status regarding receipt of a disability pension, mortality and hospitalization for lung, heart, psychiatric, and musculoskeletal disorders compared with the native population, and if there were variations in relation to sex, geographical origin, position on the labor market, and time since first immigration.MethodsThis study included migrants to Sweden since 1960 who were 28–47 years old in 1990, and included 243 860 individuals. The comparison group comprised a random sample of 859 653 native Swedes. These cohorts were followed from 1991 to 2008 in national registers. The immigrants were divided into four groups based on geographic origin. Hazard ratios for men and women from different geographic origins and with different employment status were analyzed separately for the six outcomes, with adjustment for age, education level, and income. The influence of length of residence in Sweden was analyzed separately.ResultsNordic immigrants had increased risks for all investigated outcomes while most other groups had equal or lower risks for those outcomes than the Swedes. The lowest HRs were found in the EU 15+ group (from western Europe, North America, Australia and New Zealand). All groups, except Nordic immigrants, had lower risk of mortality, but all had higher risk of disability pension receipt compared with native Swedes. Unemployed non-Nordic men displayed equal or lower HRs for most outcomes, except disability pension receipt, compared with unemployed Swedish men. A longer time since first immigration improved the health status of men, while women showed opposite results.ConclusionsEmployment status and length of residence are important factors for health. The contradictory results of low mortality and high disability pension risks need more attention. There is great potential to increase the knowledge in this field in Sweden, because of the high quality registers.

The effect of flooring on musculoskeletal symptoms in the lower extremities and low back among female nursing assistants

This study examines the effect of changing the floor from a 2-mm homogenous vinyl floor to a 4-mm heterogeneous vinyl floor (1.5-mm wear layer and 2.5-mm foam layer) on musculoskeletal symptoms in the lower extremities and low back among nursing assistants in a geriatric care centre. A pre-post design with a reference group consisting of nursing assistants from a similar geriatric care centre was used. Follow-up measurements were carried out 12 and 24 months after the intervention by means of questionnaires. At the 1-year follow-up, the pain intensity score in the feet of the intervention group had decreased compared with the baseline value and remained statistically significant at the 2-year follow-up. The decrease in pain intensity score of the feet in the intervention group was statistically significantly different from the reference group, both after 1 and 2 years. Practitioner Summary: The results show the importance of flooring in the workplace with regard to reducing musculoskeletal symptoms. Appropriate flooring is especially important in the female-dominated health care sector, where workers must stand or walk for long periods.

Different working and living conditions and their associations with persistent neck/shoulder and/or low back disorders

Objectives: To investigate whether different combinations of working and living conditions are associated with the risk for persistent neck/shoulder and/or low back disorders. The underlying purpose of this contextual approach was to identify target groups for primary/secondary prevention. Methods: In a baseline study, 11 groups with different working and living conditions were identified by cluster analysis. In this study, these 11 groups were followed up by a postal questionnaire 5 years after baseline (response rate 82%, n = 1095). Results: Five of the groups—the onerous human services job, the free agent, the family burden, the mentally stretched and the physically strained groups—had an increased risk for persistent disorders (OR 2.38–2.70). Four of these groups had rather sex-specific working and living conditions. Conclusions: The results support the hypothesis that different combinations of working and living conditions may increase the risk for persistent neck/shoulder and/or low back disorders to different degrees. Sex-specific working and living conditions increased the risk for women as well as for men, irrespective of whether the conditions were specific to women or men.

Predictive validity of the Work Ability Index and its individual items in the general population

Aim: This study assesses the predictive ability of the full Work Ability Index (WAI) as well as its individual items in the general population. Methods: The Work, Health and Retirement Study (WHRS) is a stratified random national sample of 25–75-year-olds living in Sweden in 2000 that received a postal questionnaire (n = 6637, response rate = 53%). Current and subsequent sickness absence was obtained from registers. The ability of the WAI to predict long-term sickness absence (LTSA; ⩾ 90 consecutive days) during a period of four years was analysed by logistic regression, from which the Area Under the Receiver Operating Characteristic curve (AUC) was computed. Results: There were 313 incident LTSA cases among 1786 employed individuals. The full WAI had acceptable ability to predict LTSA during the 4-year follow-up (AUC = 0.79; 95% CI 0.76 to 0.82). Individual items were less stable in their predictive ability. However, three of the individual items: current work ability compared with lifetime best, estimated work impairment due to diseases, and number of diagnosed current diseases, exceeded AUC > 0.70. Excluding the WAI item on number of days on sickness absence did not result in an inferior predictive ability of the WAI. Conclusions: The full WAI has acceptable predictive validity, and is superior to its individual items. For public health surveys, three items may be suitable proxies of the full WAI; current work ability compared with lifetime best, estimated work impairment due to diseases, and number of current diseases diagnosed by a physician.

How common is change of primary diagnosis during an episode of sickness benefit? A register study of medical sickness certificates issued 2010–2012 in Sweden

Aim: The aims of this study were to investigate how common it is to change primary diagnosis between different diagnostic chapters during a sick-leave spell, and to explore patterns of diagnostic changes. Methods: The unit for analysis was episode of sickness benefit, that is, sick leave >14 days, which commenced between 2010 and 2012 in Sweden. For each case, the primary diagnosis was retrieved from the first and last/latest medical sickness certificate, respectively. The number of days of sickness benefit was linked to the cases. Any change of primary diagnosis was analysed by diagnostic chapter according to the ICD-10, and this was done separately for women and men. Results: In total, 803,041 cases of sickness benefit (63% women) were included in the study. During a sick-leave spell, 7.1% of female cases and 6.6% of male cases changed their primary diagnosis to a diagnosis from another diagnostic chapter. The change of primary diagnosis increased with the number of days with sickness benefit. For female cases, this increase was from 2.0% for cases that lasted 15–30 days to 20.2% for cases that lasted >365 days. For male cases, the corresponding increase was from 1.8% to 21.2%. A change of primary diagnosis was least common among those initially sick-listed for mental disorders and musculoskeletal disorders. The patterns of diagnostic changes were rather similar for women and men. Conclusions: A change of diagnosis during a sick-leave spell needs to be taken into consideration by the sickness insurance system and in the actions taken by its administration. Registry-based studies of sickness insurance need to consider diagnostic changes in both the study design and the interpretation of results.