Sarah Derrett

The global burden of injury: incidence, mortality, disability-adjusted life years and time trends from the Global Burden of Disease study 2013

Background The Global Burden of Diseases (GBD), Injuries, and Risk Factors study used the disability-adjusted life year (DALY) to quantify the burden of diseases, injuries, and risk factors. This paper provides an overview of injury estimates from the 2013 update of GBD, with detailed information on incidence, mortality, DALYs and rates of change from 1990 to 2013 for 26 causes of injury, globally, by region and by country. Methods Injury mortality was estimated using the extensive GBD mortality database, corrections for ill-defined cause of death and the cause of death ensemble modelling tool. Morbidity estimation was based on inpatient and outpatient data sets, 26 cause-of-injury and 47 nature-of-injury categories, and seven follow-up studies with patient-reported long-term outcome measures. Results In 2013, 973 million (uncertainty interval (UI) 942 to 993) people sustained injuries that warranted some type of healthcare and 4.8 million (UI 4.5 to 5.1) people died from injuries. Between 1990 and 2013 the global age-standardised injury DALY rate decreased by 31% (UI 26% to 35%). The rate of decline in DALY rates was significant for 22 cause-of-injury categories, including all the major injuries. Conclusions Injuries continue to be an important cause of morbidity and mortality in the developed and developing world. The decline in rates for almost all injuries is so prominent that it warrants a general statement that the world is becoming a safer place to live in. However, the patterns vary widely by cause, age, sex, region and time and there are still large improvements that need to be made.

Disabling musculoskeletal pain in working populations: is it the job, the person, or the culture?

&NA; Large international variation in the prevalence of disabling forearm and low back pain was only partially explained by established personal and socioeconomic risk factors. &NA; To compare the prevalence of disabling low back pain (DLBP) and disabling wrist/hand pain (DWHP) among groups of workers carrying out similar physical activities in different cultural environments, and to explore explanations for observed differences, we conducted a cross‐sectional survey in 18 countries. Standardised questionnaires were used to ascertain pain that interfered with everyday activities and exposure to possible risk factors in 12,426 participants from 47 occupational groups (mostly nurses and office workers). Associations with risk factors were assessed by Poisson regression. The 1‐month prevalence of DLBP in nurses varied from 9.6% to 42.6%, and that of DWHP in office workers from 2.2% to 31.6%. Rates of disabling pain at the 2 anatomical sites covaried (r = 0.76), but DLBP tended to be relatively more common in nurses and DWHP in office workers. Established risk factors such as occupational physical activities, psychosocial aspects of work, and tendency to somatise were confirmed, and associations were found also with adverse health beliefs and group awareness of people outside work with musculoskeletal pain. However, after allowance for these risk factors, an up‐to 8‐fold difference in prevalence remained. Systems of compensation for work‐related illness and financial support for health‐related incapacity for work appeared to have little influence on the occurrence of symptoms. Our findings indicate large international variation in the prevalence of disabling forearm and back pain among occupational groups carrying out similar tasks, which is only partially explained by the personal and socioeconomic risk factors that were analysed.

Physical and psychosocial risk factors for musculoskeletal disorders in New Zealand nurses, postal workers and office workers

Objective To investigate the association of physical and psychosocial risk factors with musculoskeletal disorders (MSDs) in New Zealand nurses, postal workers and office workers. Design A cross-sectional postal survey asking about demographic, physical and psychosocial factors and MSDs. Participants A total of 911 participants was randomly selected; nurses from the Nursing Council of New Zealand database (n=280), postal workers from their employers database (n=280) and office workers from the 2005 electoral roll (n=351). Outcome Measures Self-reported pain in the low back, neck, shoulder, elbow, wrist/hand or knee lasting more than 1 day in the month before the survey. Results The response rate was 58%, 443 from 770 potential participants. 70% (n=310) reported at least one MSDs. Physical work tasks were associated with low back (odds ratio (OR) 1.35, 95% CI 1.14 to 1.6), shoulder (OR 1.41, 95% CI 1.17 to 1.69), elbow (OR 1.14, 95% CI 1.13 to 1.83) and wrist/hand pain (OR 1.39, 95% CI 1.15 to 1.69). Job strain had the strongest association with neck pain (OR 3.46, 95% CI 1.30 to 9.21) and wrist/hand pain. Somatisation was weakly associated with MSDs at most sites. Better general and mental health status were weakly associated with lower odds of MSDs. Conclusions In injury prevention and rehabilitation the physical nature of the work needs to be addressed for most MSDs, with modest decreases in risk seemingly possible. Addressing job strain could provide significant benefit for those with neck and wrist/hand pain, while the effects of somatisation and the promotion of good mental health may provide smaller but global benefits.

Prevalence and impact of musculoskeletal disorders in New Zealand nurses, postal workers and office workers.

Objectives: To describe the prevalence, characteristics and impact of musculoskeletal disorders (MSDs) in New Zealand nurses, postal workers and office workers.

Descriptive Epidemiology of Somatising Tendency: Findings from the CUPID Study

Somatising tendency, defined as a predisposition to worry about common somatic symptoms, is importantly associated with various aspects of health and health-related behaviour, including musculoskeletal pain and associated disability. To explore its epidemiological characteristics, and how it can be specified most efficiently, we analysed data from an international longitudinal study. A baseline questionnaire, which included questions from the Brief Symptom Inventory about seven common symptoms, was completed by 12,072 participants aged 20–59 from 46 occupational groups in 18 countries (response rate 70%). The seven symptoms were all mutually associated (odds ratios for pairwise associations 3.4 to 9.3), and each contributed to a measure of somatising tendency that exhibited an exposure-response relationship both with multi-site pain (prevalence rate ratios up to six), and also with sickness absence for non-musculoskeletal reasons. In most participants, the level of somatising tendency was little changed when reassessed after a mean interval of 14 months (75% having a change of 0 or 1 in their symptom count), although the specific symptoms reported at follow-up often differed from those at baseline. Somatising tendency was more common in women than men, especially at older ages, and varied markedly across the 46 occupational groups studied, with higher rates in South and Central America. It was weakly associated with smoking, but not with level of education. Our study supports the use of questions from the Brief Symptom Inventory as a method for measuring somatising tendency, and suggests that in adults of working age, it is a fairly stable trait.

Patterns of multisite pain and associations with risk factors

Summary In a large cross‐sectional survey, pain affecting 6–10 anatomical sites showed substantially different associations with risk factors from pain limited to 1–3 sites. ABSTRACT To explore definitions for multisite pain, and compare associations with risk factors for different patterns of musculoskeletal pain, we analysed cross‐sectional data from the Cultural and Psychosocial Influences on Disability (CUPID) study. The study sample comprised 12,410 adults aged 20–59 years from 47 occupational groups in 18 countries. A standardised questionnaire was used to collect information about pain in the past month at each of 10 anatomical sites, and about potential risk factors. Associations with pain outcomes were assessed by Poisson regression, and characterised by prevalence rate ratios (PRRs). Extensive pain, affecting 6–10 anatomical sites, was reported much more frequently than would be expected if the occurrence of pain at each site were independent (674 participants vs 41.9 expected). In comparison with pain involving only 1–3 sites, it showed much stronger associations (relative to no pain) with risk factors such as female sex (PRR 1.6 vs 1.1), older age (PRR 2.6 vs 1.1), somatising tendency (PRR 4.6 vs 1.3), and exposure to multiple physically stressing occupational activities (PRR 5.0 vs 1.4). After adjustment for number of sites with pain, these risk factors showed no additional association with a distribution of pain that was widespread according to the frequently used American College of Rheumatology criteria. Our analysis supports the classification of pain at multiple anatomical sites simply by the number of sites affected, and suggests that extensive pain differs importantly in its associations with risk factors from pain that is limited to only a small number of anatomical sites.

Measuring the population burden of fatal and nonfatal injury.

The value of measuring the population burden of fatal and nonfatal injury is well established. Population health metrics are important for assessing health status and health-related quality of life after injury and for integrating mortality, disability, and quality-of-life consequences. A frequently used population health metric is the disability-adjusted life-year. This metric was launched in 1996 in the original Global Burden of Disease and Injury study and has been widely adopted by countries and health development agencies alike to identify the relative magnitude of different health problems. Apart from its obvious advantages and wide adherence, a number of challenges are encountered when the disability-adjusted life-year is applied to injuries. Validation of disability-adjusted life-year estimates for injury has been largely absent. This paper provides an overview of methods and existing knowledge regarding the population burden of injury measurement. The review of studies that measured burden of injury shows that estimates of the population burden remain uncertain because of a weak epidemiologic foundation; limited information on incidence, outcomes, and duration of disability; and a range of methodological problems, including definition and selection of incident and fatal cases, choices in selection of assessment instruments and timings of use for nonfatal injury outcomes, and the underlying concepts of valuation of disability. Recommendations are given for methodological refinements to improve the validity and comparability of future burden of injury studies.

Prospective outcomes of injury study

Background: In New Zealand (NZ), 20% of adults report a disability, of which one-third is caused by injury. No prospective epidemiological studies of predictors of disability following all-cause injury among New Zealanders have been undertaken. Internationally, studies have focused on a limited range of predictors or specific injuries. Although these studies provide useful insights, applicability to NZ is limited given the importance of NZ’s unique macro-social factors, such as NZ’s no-fault accident compensation and rehabilitation scheme, the Accident Compensation Corporation (ACC). Objectives: (1) To quantitatively determine the injury, rehabilitation, personal, social and economic factors leading to disability outcomes following injury in NZ. (2) To qualitatively explore experiences and perceptions of injury-related outcomes in face-to-face interviews with 15 Māori and 15 other New Zealanders, 6 and 12 months after injury. Setting: Four geographical regions within NZ. Design: Prospective cohort study with telephone interviews 1, 4 and 12 months after injury. Participants: 2500 people (including 460 Māori), aged 18–64 years, randomly selected from ACC’s entitlement claims register (people likely to be off work for at least 1 week or equivalent). Data: Telephone interviews, electronic hospital and ACC injury data. Exposures include demographic, social, economic, work-related, health status, participation and/or environmental factors. Outcome measures: Primary: disability (including WHODAS II) and health-related quality of life (including EQ-5D). Secondary: participation (paid and unpaid activities), life satisfaction and costs. Analysis: Separate regression models will be developed for each of the outcomes. Repeated measures outcomes will be modelled using general estimating equation models and generalised linear mixed models.

Prospective Outcomes of Injury Study: recruitment, and participant characteristics, health and disability status

The Prospective Outcomes of Injury Study aims to identify predictors of disability following injury. Participants were selected from the entitlement claims register of New Zealands no-fault compensation insurer, the Accident Compensation Corporation, and followed up by interview for 2 years. This report describes changes to intended Prospective Outcomes of Injury Study methods and key characteristics of the cohort, with an emphasis on general health and disability before injury and soon afterwards. There were 2856 injured participants in the first interview, which occurred 3.2 months (median) after injury. The recruitment period was extended to enable inclusion of sufficient Māori participants. At the first interview, most participants were experiencing worse health status and increased disability compared to before injury, despite less than one-third reporting admission to hospital because of their injury. Analysis of outcome predictors related to post-injury function, disability and return-to-work soon after injury and 1 year later is now under way.

Outcome After Injury-A Systematic Literature Search of Studies Using the EQ-5D

PURPOSE Information is required about recovery after injury, including general health measures such as the EQ-5D. This project aimed to: (1) search for studies of injury outcome using the EQ-5D, (2) describe EQ-5D administration and analysis, (3) summarize reliability and validity, and (4) report EQ-5D outcomes. METHODS A systematic search was undertaken for publications (January 1990 to May 2008). Studies were excluded if the EQ-5D was not used or if injury was a secondary outcome or resulted from a degenerative condition. RESULTS Of 79 potentially eligible articles retrieved, 35 were excluded and 44 remained. Sample sizes ranged between n = 14 and n = 3,231. Two thirds of studies described injury outcomes, the remainder focused on specific treatments after injury. Of studies reporting EQ-5D index scores, most used the UK value set, and 29% did not specify a value set. In 16 studies, the EQ-5D was self-completed by participants, and in others, administration was by interviewer, proxy, or unspecified. Time of administration varied between 6 days and 7 years after injury. The absence of a cognitive dimension in the EQ-5D was a concern. DISCUSSION Given the global impact of injury-related disability, our search supports calls for comprehensive population-level research exploring outcomes. Many studies considered only specific treatments after injury, had small sample sizes, or were undertaken in wealthy countries. Although noting reservations about the EQ-5D, such as the absence of a cognitive dimension; the EQ-SD being freely available to nonprofit-making organizations, and with many language versions available, seems suitable for studies in wealthy and poorer nations alike.