Post-injury long-term sickness absence and risk of disability pension: The role of socioeconomic status.

INTRODUCTION: Previous research has identified low socioeconomic status (SES) as a risk factor for long-term sickness absence (LTSA) and disability pension (DP) following trauma. However, most studies lack information on medical diagnoses, limiting our understanding of the underlying factors. To address this gap, we retrieved information about diagnostic causes for receipt of welfare benefits to explore the role of SES in the transition from post-injury LTSA to permanent DP among the working population in Norway. MATERIALS AND METHODS: We conducted a population-based cohort study of all Norwegian residents aged 25-59 years registered with a spell of LTSA due to injury commencing in the period 2000-2003. This cohort was followed through 2014 by linking information on receipt of welfare benefits with sociodemographic data from administrative registers. SES was defined as a composite measure of educational attainment and income level. We used flexible parametric survival models to estimate hazard ratios (HR) with 95 % confidence intervals (CI) for all-cause and diagnosis-specific DP according to SES, adjusting for sex, age, marital status, immigrant status and healthcare region of residence. RESULTS: Of 53,937 adults with post-injury LTSA, 9,665 (18 %) transferred to DP during follow-up. The crude risk of DP was highest for LTSA spells due to poisoning and head injuries. Overall, individuals in the lowest SES category had twice the risk of DP compared to those in the highest SES category (HR = 2.25, 95 % CI 2.13-2.38). The difference by SES was greatest for LTSA due to poisoning and smallest for LTSA due to head injuries. A majority (75 %) of DP recipients had a non-injury diagnosis as the primary cause of DP. The socioeconomic gradient was more pronounced for non-injury causes of DP (HR = 2.47, 95 % CI 2.31-2.63) than for injury causes (HR = 1.73, 95 % CI 1.56-1.92) and was especially steep for DP due to musculoskeletal diseases and mental and behavioural disorders. CONCLUSIONS: The relationship between SES and DP varied by both the type of injury that caused LTSA and the diagnosis used to grant DP, highlighting the importance of taking diagnostic information into account when investigating long-term consequences of injuries.

Injury severity and increased socioeconomic differences: A population-based cohort study.

BACKGROUND: Several studies have documented an inverse gradient between socioeconomic status (SES) and injury mortality, but the evidence is less consistent for injury morbidity. The aim of this study was to investigate the association between SES and injury severity for acute hospitalizations in a nationwide population-based cohort. METHODS: We conducted a registry-based cohort study of all individuals aged 25-64 years residing in Norway by 1st of January 2008. This cohort was followed from 2008 through 2014 using inpatient registrations for acute hospitalizations due to all-cause injuries. We derived two measures of severity: threat-to-life using the International Classification of Disease-based Injury Severity Score (ICISS), and threat of disability using long-term disability weights from the Injury-VIBES project. Robust Poisson regression models, with adjustment for age, sex, marital status, immigrant status, municipality population size and healthcare region of residence, were used to calculate incidence rate ratios (IRRs) by SES measured as an index of education, income, and occupation. RESULTS: We identified 177,663 individuals (7% of the population) hospitalized with at least one acute injury in the observation period. Two percent (n = 4,186) had injuries categorized with high threat-to-life, while one quarter (n = 43,530) had injuries with high threat of disability. The overall adjusted IRR of hospitalization among people with low compared to high SES was 1.57 (95% CI 1.55, 1.60). Comparing low to high SES, injuries with low threat-to-life were associated with an IRR of 1.56 (95% CI 1.54, 1.59), while injuries with high threat-to-life had an IRR of 2.25 (95% CI 2.03, 2.51). Comparing low to high SES, injuries with low, medium, and high threat of disability were associated with IRRs of respectively, 1.15 (95% CI 1.11, 1.19), 1.70 (95% CI 1.66, 1.73) and 1.99 (95% CI 1.92, 2.07). DISCUSSION: We observed an inverse gradient between SES and injury morbidity, with the steepest gradient for the most severe injuries. This suggests a need for targeted preventive measures to reduce the magnitude and burden of severe injuries for patients with low socioeconomic status.

Incidence of injuries in Norway: linking primary and secondary care data.

Aims: Most studies of injury incidence underestimate the total burden of injury, as they do not include injuries treated in primary care. The aim of this study was to measure the total incidence of medically treated injuries in Norway. We further investigated the epidemiology of injuries treated in primary and secondary care. Methods: We collected individual-level data on injury diagnoses from the Norwegian Patient Registry and the national registry dataset for reimbursement of primary care providers for the period 2009-2014, and estimated the annual incidence of patients registered with an injury diagnosis in either or both of these registries. We also converted ICD-10 codes in secondary care into ICPC-2 codes to compare the types of injuries treated in primary and secondary care. Results: The annual incidence of medically treated injuries in Norway was 125 patients per 1000 inhabitants. Fifty-five per cent of injured patients received treatment exclusively in primary care. We observed stable time trends over the six-year period. Incidence rates were higher in primary care for the youngest children and in middle adulthood, but were higher in secondary care for older people. Overall, injury incidence was higher for men, but women became more injury prone with age. We only observed this gender reversal in secondary care. With the exception of fractures, all injury types were predominantly treated in primary care. Conclusions: A substantial proportion of injured patients in Norway are treated exclusively in primary care. The demographic profile of these patients differs from those treated in secondary care.

The Oslo Health Study: Is bone mineral density higher in affluent areas?

BACKGROUND: Based on previously reported differences in fracture incidence in the socioeconomic less affluent Oslo East compared to the more privileged West, our aim was to study bone mineral density (BMD) in the same socioeconomic areas in Oslo. We also wanted to study whether possible associations were explained by socio-demographic factors, level of education or lifestyle factors. METHODS: Distal forearm BMD was measured in random samples of the participants in The Oslo Health Study by single energy x-ray absorptiometry (SXA). 578 men and 702 women born in Norway in the age-groups 40/45, 60 and 75 years were included in the analyses. Socioeconomic regions, based on a social index dividing Oslo in two regions - East and West, were used. RESULTS: Age-adjusted mean BMD in women living in the less affluent Eastern region was 0.405 g/cm2 and significantly lower than in West where BMD was 0.419 g/cm2. Similarly, the odds ratio of low BMD (Z-score

Bone mineral density in ethnic Norwegians and Pakistani immigrants living in Oslo--The Oslo Health Study.

Bone mineral density (BMD, grams per square centimeter) is scarcely studied in immigrants from the Indian subcontinent. Pakistani immigrants in Oslo, Norway, have a very high prevalence of vitamin D deficiency. Thus, it is of great interest to compare BMD between Pakistani immigrants and ethnic Norwegians in Oslo. The comparison was done with and without adjustment for skeletal size, and we examined whether known risk factors explained possible differences in bone density between these two ethnic groups. BMD was measured at the distal and ultra-distal forearm site in a random sample of the participants in the Oslo Health Study by single energy X-ray absorptiometry (SXA). One hundred and seventy-three Pakistani-born subjects (71 women, 102 men) and 1,386 Norwegian-born subjects (675 women, 711 men) aged 30, 40, 45 and 59/60 years, living in Oslo, were included in the analysis. To account for variation in skeletal size, we computed height-adjusted BMD values, BMD/height (grams per cubic centimeter), and volumetric bone mineral apparent density (BMAD, grams per cubic centimeter). We found no differences in distal or ultra-distal forearm BMD between Pakistanis and Norwegians in either women or men. We found, however, higher values in Pakistani men when BMD was height-adjusted (2% higher in distal sites and 5% in ultra-distal sites). We also found higher bone mass values (both distal and ultra-distal) in Pakistani women and men than in their Norwegian counterparts when volumetric measures, such as BMD/height (7%-8% higher in women, 6%-7% in men) and BMAD (6% higher in women, 8% in men), were used. In a regression model that included ethnicity, anthropometry and lifestyle factors, BMD was higher in Pakistani men than in Norwegian men, but not in women. We conclude that Pakistanis living in Oslo have similar BMD to ethnic Norwegians, but they have higher volumetric bone mass values. When we adjusted for confounders we found higher BMD values in Pakistani men than in Norwegian men.