Tip of the iceberg: unveiling the impact on back disorders from cumulative physical job exposure and evaluating bias from the healthy worker effect using a nationwide longitudinal cohort study.

PURPOSE: Longitudinal studies across various sectors with physically demanding jobs are notably absent in back disorder risk research. This study aimed to investigate the relationship between cumulative physical job exposure (PJE) and hospital-diagnosed back disorders among individuals in Denmark. To assess the healthy worker effect, we compared the cumulative risk estimate with results from a naive cross-sectional model ignoring PJE history. METHODS: A nationwide longitudinal cohort study was conducted using Danish registers, encompassing individuals born between 1975 and 1978 and working in 1996. Cumulative PJE was measured with a 10-year look-back period for each year 2006-2017. PJE consisted of lower-body occupational exposures, including the total weight lifted, stand/sit ratio, and the frequency of lifting more than 20 kg per day from a job exposure matrix. Odds ratio for back disorders was estimated for each year and all years combined. RESULTS: The results unveiled a significant 31% increase in the risk of hospital-diagnosed back disorders after 4 years of cumulative PJE. The lowest risk (7%) was observed for incident back disorders with 1 year of exposure, suggesting a healthy worker effect. Nevertheless, this risk is still significantly elevated. This cumulative estimate is fourfold the estimate from the 2006 naive cross section model. CONCLUSION: Our study clearly demonstrates an 31% increase in the risk of hospital-diagnosed back disorders with just 4 years of PJE over a 10-year period. Further, we find that cross-sectional studies strongly underestimate the risk of back disorders due to the healthy worker effect.

Back disorder incidence and occupation in Denmark: a cross-sectional register-based study.

PURPOSE: The purpose of the present paper is (1) to describe the occupational distribution of persons with incident back disorders and (2) to determine the incidence rate ratio (RR) for back pain amongst patients working in specific occupation groups. METHODS: Using Danish registries, a total of 20,921 employed persons with incidents back disorders aged 18-64 years were identified in 2016 based on the inclusion criteria from the Danish Back Register. RR was estimated to test for differences in incident back disorder diagnoses across occupations. Pearson's Chi-square test was used to test for homogeneity in back disorder incidence across occupations. RESULTS: The distribution of back disorder incidence for employed is above the distribution of employment in the background population for all age groups above 35 years. For employed women the three occupation groups with the highest RR of back pain incidence are: 'water, sewage and waste'; 'residential institutions and home care'; and 'transport of passengers', while similarly, amongst employed men: 'hairdressers and other personal care'; 'hospitals'; and 'cleaning'. RR of incident back pain disorders is lowest for women employed in 'universities and research' and for men employed in 'IT and telecommunications'. CONCLUSIONS: This study is the first to investigate the occupational status and RR of back disorder incidence across occupation groups in Denmark. The distribution of back pain disorder incidents in the cross-sectional study is weighted to occupation groups involving hard physical activity. This evidence may be useful for considering work environment or pension reforms. These slides can be retrieved under Electronic Supplementary Material.

Predictive validity of PRISMA-7 as a screening instrument for frailty in a hospital setting.

OBJECTIVES: Frailty is a major clinical geriatric syndrome associated with serious adverse events including functional disability, falls, hospitalisation, increased morbidity and mortality. The aim of this study was to study the associations between frailty defined as Program of Research to Integrate Services for the Maintenance of Autonomy (PRISMA-7) score ≥3 and use of healthcare resources in hospital and in the municipality as well as association between frailty and mortality. DESIGN: Register-based retrospective study. SETTING: The target population consists of patients aged 75 years or above who, during hospital stay, were assessed by a physiotherapist, and at discharge from hospital were prescribed further physical training in the community. PARTICIPANTS: 973 individuals aged 75+ years were included. OUTCOME MEASURES: We examined associations between frailty and use of healthcare resources in hospital and in the municipality as well as the association between frailty and mortality. RESULTS: 973 individuals aged 75+ years were included. Of these, 63.9% had a PRISMA-7 score ≥3 and were thus defined as frail. Frail individuals were older compared with non-frail with mean ages of 84.6 and 80.4 years, respectively, p>0.001. Age and gender-adjusted mortality after 1 year was higher among the frail (OR 2.46, 95% CI 1.53 to 3.97). Use of healthcare services in the municipality as well as hospital admissions was significantly higher among frail individuals. CONCLUSIONS: Based on these findings we consider PRISMA-7 to be useful in an in-hospital setting as a screening tool to identify frail elderly patients who may profit from further geriatric assessment during hospital stay. TRIAL REGISTRATION NUMBER: ID REG-070-2017.