Teresia Nyman

Sickness absence and concurrent low back and neck–shoulder pain: results from the MUSIC-Norrtälje study

In Sweden, musculoskeletal disorders, in particular low back disorders (LBD) and neck–shoulder disorders (NSD) constitute by far the most common disorders, causing sick leave and early retirement. Studies that compare sickness absence in individuals with LBD and individuals with NSD are lacking. Moreover, it is likely that having concurrent complaints from the low back region and the neck–shoulder region could influence sickness absence. The purpose of the present study was to explore potential differences in sickness absence and in long-term sickness absence during a 5-year period, 1995–2001, among individuals with (1) solely LBD, (2) solely NSD, and (3) concurrent LBD and NSD. The present study was based on 817 subjects from the MUSIC-Norrtalje study, whom were working at baseline and whom at both baseline and follow-up reported LBD and/or NSD. Three groups were identified based on pain and pain-related disability at both baseline and follow-up: (1) solely LBD, (2) solely NSD, and (3) concurrent LBD and NSD. Subjects who did not give consistent answers at both the baseline and follow-up occasions were assigned a fourth group: (4) migrating LBD/NSD. Two outcomes were analysed: (1) prevalence of sickness absence, and (2) long-term sickness absence among those with sickness absence days. Logistic regression analysis was used to calculate odds ratios (OR) for sickness absence in the different disorder groups, taking into account confounding factors such as gender, age and other non-musculoskeletal-related disorders. In the group concurrent LBD and NSD, 59% had been sickness absent between baseline and follow up, compared to 42% in the group solely LBD, 41% in the group solely NSD, and 46% in the group migrating LBD/NSD. No difference in sickness absence was found between the group solely LBD compared to the group solely NSD [OR 0.65 (0.36–1.17)]. The adjusted OR for sickness absence in the group concurrent LBD and NSD compared to subjects with solely LBD or solely NSD was [OR 1.69 (1.14–2.51)]. The adjusted OR for having long-term sickness absence was 2.48 (95% CI = 1.32–4.66) for the group concurrent LBD and NSD. In the present study, having concurrent LBD and NSD were associated with a higher risk for sickness absence and also long-term sickness absence. This suggests that, when research on sickness absence and return to work after a period of LBD or NSD is performed, it is important to take into consideration any concurrent pain from the other spinal region. The study also implies that spinal co-morbidity is an important factor to be considered by clinicians and occupational health providers in planning treatment, or in prevention of these disorders.

High heritability for concurrent low back and neck-shoulder pain: a study of twins.

Study Design. A cross-sectional study on 21,225 twins based on a Web-based questionnaire was performed in 2005–2006 and administered by the Swedish Twin Registry. Objective. To investigate the importance of genetic factors for the occurrence of “Concurrent low back (LBP) and neck-shoulder pain (NSP)” as well as of “Solely LBP,” and “Solely NSP” in an adult population of women and men. Summary of Background Data. Many individuals suffering from LBP also have concurrent NSP, and little is known about the factors influencing the occurrence of this spinal comorbidity. Methods. Heritability of Concurrent LBP and NSP, solely LBP, and solely NSP was analyzed in 2934 monozygotic twin pairs, 2009 same-sex dizygotic (DZ) twin pairs, and 1960 opposite-sex DZ twin pairs without any known rheumatic disorders using structural equation modeling (SEM). Results. The SEM showed that 60% of the total variance for concurrent LBP and NSP can be explained by additive genetic effects, which was twice as large as for solely LBP (30%) and more than twice as large as for solely NSP (24%). Conclusion. Genetic factors had a considerably greater importance for the occurrence of concurrent LBP and NSP compared with solely LBP or solely NSP. The influence of genetic factors was similar for solely LBP and solely NSP.

Sleep as a predictive factor for the onset and resolution of multi-site pain: A 5-year prospective study

Disturbed sleep and pain often co‐exist and the relationship between the two conditions is complex and likely reciprocal. This 5‐year prospective study examines whether disturbed sleep can predict the onset of multi‐site pain, and whether non‐disturbed sleep can predict the resolution of multi‐site pain.

Physical workload, low back pain and neck-shoulder pain - a Swedish twin study

Objectives: To investigate if high physical workload is associated with low back pain (LBP) and/or neck–shoulder pain (NSP) when taking into account the influence of genetic and shared environmental factors. Further, the study aims to explore the potential influence of genetic and shared environmental factors in the associations between high physical workload and the three disorder subgroups: solely LBP, solely NSP, and concurrent LBP and NSP. Methods: Data on 16 107 monozygotic and dizygotic twins, born during 1959–1985, were obtained from a cross-sectional study, performed in 2005–2006 by the Swedish Twin Registry. Odds ratios (ORs) calculated in cohort analyses and co-twin control analyses were used to assess the associations between high physical workload and LBP and NSP when controlling for genetic and shared environmental factors. Results: In the cohort analysis, the association between high physical workload and the group with any one symptom (LBP and/or NSP) was OR 1.47 (95% CI 1.37 to 1.57). The co-twin control analyses indicated that the association was not confounded by genetic and shared environmental factors with OR 1.34 (95% CI 1.02 to 1.75) for dizygotic twins and OR 1.44 (95% CI 1.06 to 1.95) for monozygotic twins. In the cohort analyses the association with high physical workload was higher for concurrent LBP and NSP (OR 1.80 (95% CI 1.62 to 1.99)) than for solely LBP (OR 1.41 (95% CI 1.27 to 1.57)) and solely NSP (OR 1.31 (95% CI 1.20 to 1.43)). Concurrent LBP and NSP was the only group that showed a stepwise decrease of the point estimates between the cohort analysis and the co-twin control analyses, OR 1.71 (95% CI 1.00 to 2.94) for dizygotic twins, and OR 1.29 (95% CI 0.64 to 2.59) for monozygotic twins indicating confounding by genetic and shared environmental factors. Conclusions: High physical workload was associated with LBP and/or NSP even after adjusting for genetic or shared environmental factors. Only for concurrent LBP and NSP, genetic and shared environmental factors seemed to have an influence on the association with high physical workload.