Alternative approaches to derive disability weights in injuries: do they make a difference?

Humeral shaft fractures: a cost-effectiveness analysis of operative versus nonoperative management

BACKGROUND

Humeral shaft fractures can be managed operatively or nonoperatively with functional bracing in the absence of neurovascular injury, open fracture, or polytrauma. A consensus on optimal management has not been reached, nor has the cost-effectiveness perspective been investigated.

METHODS

A decision tree was constructed describing the management of humeral shaft fractures with open reduction-internal fixation (ORIF), intramedullary nailing (IMN), and functional bracing in a non-elderly population. Probabilities were defined using weighted averages determined from systematic review of the literature. Cost-effectiveness was evaluated with incremental cost-effectiveness ratios, measured in cost per quality-adjusted life-year (QALY). Willingness-to-pay thresholds of $50,000/QALY and $100,000/QALY were evaluated.

RESULTS

Eighty-six studies were included. Using bracing as the referent in the health care model, we observed that bracing was the preferred strategy at both incremental cost-effectiveness ratio thresholds. ORIF and IMN had higher overall effectiveness (0.917 QALYs and 0.913 QALYs, respectively) compared with bracing (0.877 QALYs). The cost-effectiveness of bracing was driven by a substantially lower overall cost. In the societal model-accounting for both health care and societal costs-the cost difference narrowed between bracing, ORIF, and IMN. Bracing remained the preferred strategy at the $50,000/QALY threshold; ORIF was preferred at the $100,000/QALY threshold. ORIF and IMN were comparable strategies across a range of probability values in sensitivity analyses.

CONCLUSIONS

Functional bracing, with its low cost and satisfactory clinical outcomes, is often the most cost-effective strategy for humeral shaft fracture management. ORIF becomes preferable at the higher willingness-to-pay threshold when societal burden is considered. QALY values for ORIF and IMN were comparable.

A systematic literature review of disability weights measurement studies: evolution of methodological choices

Background

The disability weight is an essential factor to estimate the healthy time that is lost due to living with a certain state of illness. A 2014 review showed a considerable variation in methods used to derive disability weights. Since then, several sets of disability weights have been developed. This systematic review aimed to provide an updated and comparative overview of the methodological design choices and surveying techniques that have been used in disability weights measurement studies and how they evolved over time.

Methods

A literature search was conducted in multiple international databases (early-1990 to mid-2021). Records were screened according to pre-defined eligibility criteria. The quality of the included disability weights measurement studies was assessed using the Checklist for Reporting Valuation Studies (CREATE) instrument. Studies were collated by characteristics and methodological design approaches. Data extraction was performed by one reviewer and discussed with a second.

Results

Forty-six unique disability weights measurement studies met our eligibility criteria. More than half (n = 27; 59%) of the identified studies assessed disability weights for multiple ill-health outcomes. Thirty studies (65%) described the health states using disease-specific descriptions or a combination of a disease-specific descriptions and generic-preference instruments. The percentage of studies obtaining health preferences from a population-based panel increased from 14% (2004–2011) to 32% (2012–2021). None of the disability weight studies published in the past 10 years used the annual profile approach. Most studies performed panel-meetings to obtain disability weights data.

Conclusions

Our review reveals that a methodological uniformity between national and GBD disability weights studies increased, especially from 2010 onwards. Over years, more studies used disease-specific health state descriptions in line with those of the GBD study, panel from general populations, and data from web-based surveys and/or household surveys. There is, however, a wide variation in valuation techniques that were used to derive disability weights at national-level and that persisted over time.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-022-00860-z.

Rockwood Grade-III Acromioclavicular Joint Separation: A Cost-Effectiveness Analysis of Treatment Options

Background:

The treatment of Rockwood Grade-III acromioclavicular (AC) joint separation has been widely disputed since the introduction of the classification system. The present literature does not reach consensus on whether operative or nonoperative management is more advantageous, nor does it effectively distinguish between operative measures. We hypothesized that nonoperative treatment of Rockwood Grade-III AC joint separation would be more cost-effective when compared with surgical options.

Methods:

We created a decision-tree model outlining the treatment of Rockwood Grade-III separations using nonoperative management or hook-plate, suture-button, or allograft fixation. After nonoperative intervention, the possible outcomes predicted by the model were uneventful healing, delayed operative management, a second round of sling use and physical therapy, or no reduction and no action; and after operative intervention, the possible outcomes were uneventful healing, loss of reduction and revision, and depending on the implant, loss of reduction and no action, or removal of the implant. A systematic review was conducted, and probabilities of each model state were averaged. A cost-effectiveness analysis was conducted both through rollback analysis yielding net monetary benefit and through incremental cost-effectiveness ratios (ICERs). Thresholds of $50,000/quality-adjusted life-year (QALY) and $100,000/QALY were used for ICER analysis. Furthermore, a sensitivity analysis was utilized to determine whether differential probabilities could impact the model.

Results:

Forty-five papers were selected from a potential 768 papers identified through our literature review. Nonoperative treatment was used as our reference case and showed dominance over all 3 of the operative measures at both the $50,000 and $100,000 ICER thresholds. Nonoperative treatment also showed the greatest net monetary benefit. Nonoperative management yielded the lowest total cost ($6,060) and greatest utility (0.95 QALY). Sensitivity analysis showed that allograft fixation became the favored technique at a willingness-to-pay threshold of $50,000 if the rate of failure of nonoperative treatment rose to 14.6%. Similarly, at the $100,000 threshold, allograft became dominant if the probability of failure of nonoperative treatment rose to 22.8%.

Conclusions:

The cost-effectiveness of nonoperative treatment is fueled by its notably lower costs and overall high rates of success in Grade-III separations. It is important to note that, in our analysis, the societal cost (measured in lost productivity) of nonoperative treatment neared that of surgical treatment, but the cost from the health-care system perspective was minimal. Physicians should bear in mind the sensitivity of these conclusions and should consider cost-effectiveness analyses in their decision-making guidelines.

Level of Evidence:

Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

Social and economic cost of eating disorders in the United States: Evidence to inform policy action

OBJECTIVE

To estimate one-year costs of eating disorders in the United States (U.S.) from a societal perspective, including the costs to the U.S. health system, individual and family productivity costs, lost wellbeing, and other societal economic costs, by setting and payer. Findings will inform needed policy action to mitigate the impact of eating disorders in the U.S.

METHOD

Costs of eating disorders were estimated using a bottom-up cost-of-illness methodology, based on the estimated one-year prevalence of eating disorders. Intangible costs of reduced wellbeing were also estimated using disability-adjusted life years.

RESULTS

Total economic costs associated with eating disorders were estimated to be $64.7 billion (95% CI: $63.5-$66.0 billion) in fiscal year 2018-2019, equivalent to $11,808 per affected person (95% CI: $11,754-$11,863 per affected person). Otherwise Specified Feeding or Eating Disorder accounted for 35% of total economic costs, followed by Binge Eating Disorder (30%), Bulimia Nervosa (18%) and Anorexia Nervosa (17%). The substantial reduction in wellbeing associated with eating disorders was further valued at $326.5 billion (95% CI: $316.8-$336.2 billion).

DISCUSSION

The impact of eating disorders in the U.S. is substantial when considering both economic costs and reduced wellbeing (nearly $400 billion in fiscal year 2018-2019). Study findings underscore the urgency of identifying effective policy actions to reduce the impact of eating disorders, such as through primary prevention and screening to identify people with emerging or early eating disorders in primary care, schools, and workplaces and ensuring access to early evidence-based treatment.

Quantification of injury burden using multiple data sources: a longitudinal study

Quantification of injury burden is vital for injury prevention, as it provides a guide for setting policies and priorities. This study generated a set of Hong Kong specific disability weights (DWs) derived from patient experiences and hospital records. Patients were recruited from the Accident and Emergency Department (AED) of three major trauma centers in Hong Kong between September 2014 and December 2015 and subsequently interviewed with a focus on health-related quality of life at most three times over a 12-month period. These patient-reported data were then used for estimation of DWs. The burden of injury was determined using the mortality and inpatient data from 2001 to 2012 and then compared with those reported in the UK Burden of Injury (UKBOI) and global burden of diseases (GBD) studies. There were 22,856 mortality cases and 817,953 morbidity cases caused by injuries, in total contributing to 1,027,641 disability-adjusted life years (DALYs) in the 12-year study timeframe. Estimates for DALYs per 100,000 in Hong Kong amounted to 1192, compared with 2924 in UKBOI and 3459 in GBD. Our findings support the use of multiple data sources including patient-reported data and hospital records for estimation of injury burden.

Updating Disability Weights for Measurement of Healthy Life Expectancy and Disability-adjusted Life Year in Korea

BACKGROUND

The present study aimed to update the methodology to estimate cause-specific disability weight (DW) for the calculation of disability adjusted life year (DALY) and health-adjusted life expectancy (HALE) based on the opinion of medical professional experts. Furthermore, the study also aimed to compare and assess the size of DW according to two analytical methods and estimate the most valid DW from the perspective of years lost due to disability and HALE estimation.

METHODS

A self-administered web-based survey was conducted ranking five causes of disease. A total of 901 participants started the survey and response data of 806 participants were used in the analyses. In the process of rescaling predicted probability to DW on a scale from 0 to 1, two models were used for two groups: Group 1 (physicians and medical students) and Group 2 (nurses and oriental medical doctors). In Model 1, predicted probabilities were rescaled according to the normal distribution of DWs. In Model 2, the natural logarithms of predicted probabilities were rescaled according to the asymmetric distribution of DWs.

RESULTS

We estimated DWs for a total of 313 causes of disease in each model and group. The mean of DWs according to the models in each group was 0.490 (Model 1 in Group 1), 0.378 (Model 2 in Group 1), 0.506 (Model 1 in Group 2), and 0.459 (Model 2 in Group 2), respectively. About two-thirds of the causes of disease had DWs of 0.2 to 0.4 in Model 2 in Group 1. In Group 2, but not in Group 1, there were some cases where the DWs had a reversed order of severity.

CONCLUSION

We attempted to calculate DWs of 313 causes of disease based on the opinions of various types of medical professionals using the previous analysis methods as well as the revised analysis method. The DWs from this study can be used to accurately estimate DALY and health life expectancy, such as HALE, in the Korean population.

Comparison of three different methods to estimate the burden of disease of burn injuries in Western Australia in 2011-2018

BACKGROUND

Priority setting and resource allocation in health care, surveillance and interventions is based increasingly on burden of disease. Several methods exist to calculate the non-fatal burden of disease of burns expressed in years lived with disability (YLDs). The aim of this study was to assess the burden of disease due to burns in Western Australia 2011-2018 and compare YLD outcomes between three existing methods.

METHODS

Data from the Burns Service of Western Australia was used. Three existing methods to assess YLDs were compared: the Global Burden of Disease (GBD) method, a method dedicated to assess injury YLDs (Injury-VIBES), and a method dedicated to assess burns YLDs (INTEGRIS-burns).

RESULTS

Incidence data from 2,866 burn patients were used. Non-fatal burden of disease estimates differed substantially between the different methods. Estimates for 2011-2018 ranged between 610 and 1,085 YLDs per 100.000 based on the Injury-VIBES method; between 209 and 324 YLDs based on the INTEGRIS-burns method; and between 89 and 120 YLDs based on the GBD method. YLDs per case were three to nine times higher when the Injury-VIBES method was applied compared to the other methods. Also trends in time differed widely through application of the different methods. There was a strong increase in YLDs over the years when the Injury-VIBES method was applied, a slight increase when the INTEGRIS-burns method was applied and a stable pattern when the GBD method was applied.

CONCLUSION

This study showed that the choice for a specific method heavily influences the non-fatal burden of disease expressed in YLDs, both in terms of annual estimates as well as in trends over time. By addressing the methodological limitations evident in previously published calculations of the non-fatal burden of disease, the INTEGRIS-burns seems to present a method to provide the most robust estimates to date, as it is the only method adapted to the nature of burn injuries and their recovery.

Neer Type-II Distal Clavicle Fractures: A Cost-Effectiveness Analysis of Fixation Techniques

BACKGROUND

Neer type-II distal clavicle fractures are unstable and are generally appropriately managed with operative fixation. Fixation options include locking plates, hook plates, and suture button devices. No consensus on optimal technique exists.

METHODS

A decision tree model was created describing fixation of Neer type-II fractures using hook plates, locking plates, or suture buttons. Outcomes included uneventful healing, symptomatic implant removal, deep infection requiring debridement, and nonunion requiring revision. Weighted averages derived from a systematic review were used for probabilities. Cost-effectiveness was evaluated by calculating incremental cost-effectiveness ratios (ICERs). The ICER is defined as the ratio of the difference in cost and difference in effectiveness of each strategy, and is measured in cost per quality-adjusted life year (QALY). The model was evaluated using thresholds of $50,000/QALY and $100,000/QALY. Sensitivity analysis was performed on all outcome probabilities for each fixation strategy to assess cost-effectiveness across a range of values.

RESULTS

Forty-three papers met final inclusion criteria. Using suture buttons as the reference case in the health-care cost model, suture button repair was dominant (both less expensive and clinically superior). Hook plates cost substantially more ($5,360.52) compared with suture buttons and locking plates ($3,713.50 and $4,007.44, respectively). Suture buttons and locking plates yielded similar clinical outcomes (0.92 and 0.91 QALY, respectively). Suture button dominance persisted in the societal perspective model. Sensitivity analysis on outcome probabilities showed that locking plates became the most cost-effective strategy if the revision rate after their use was lowered to 2.2%, from the overall average in the sources of >19%. No other changes in outcome probabilities for any of the 3 techniques allowed suture buttons to be surpassed as the most cost-effective.

CONCLUSIONS

The cost-effectiveness of suture buttons is driven by low revision rates and high uneventful healing rates. Similar QALY values for locking plate and suture button fixation were observed, which is consistent with existing literature that has failed to identify either as the clinically superior technique. Cost-effectiveness should fit prominently into the decision-making rubric for these injuries.

LEVEL OF EVIDENCE

Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Cost-Effectiveness Analysis of Syndesmotic Screw Versus Suture Button Fixation in Tibiofibular Syndesmotic Injuries

OBJECTIVES

To evaluate the cost effectiveness of suture buttons compared with syndesmotic screws for repair of tibiofibular syndesmotic injuries.

METHODS

A decision tree model was constructed to describe outcomes after syndesmosis repair using suture buttons and syndesmotic screws from the perspective of a capitated health care system. Outcomes were uneventful healing, removal of symptomatic implants, deep infection, and persistent diastasis requiring revision. Weighted literature averages were used to estimate variables for a baseline model. Outcomes were measured in quality adjusted life years. Procedure and implant costs were derived from Medicare reimbursement rates and the University Health System Consortium. An incremental cost-effectiveness ratio threshold of $50,000 per quality-adjusted life years was used to evaluate cost effectiveness.

RESULTS

The baseline model did not identify suture buttons to be cost effective. Sensitivity analysis demonstrates the model to be exquisitely sensitive to small changes in reoperation rates and implant price. At median University Health System Consortium implant prices, if the removal rate for symptomatic screws is below 13.7%, then screws are cost effective. If the screw removal rate is greater than 17.5%, then a suture button is cost effective. Within this interval, detailed analysis of the model suggests that screws may be the cost-effective strategy, but that determination should be taken with caution.

CONCLUSIONS

Moving away from the practice of routinely removing all syndesmotic screws has changed the financial landscape of syndesmosis repair. At their median cost, suture buttons are likely to be cost effective over screws for symptomatic screw removal rates greater than 17.5%. Cost effectiveness is sensitive to changes in implant removal rates and the number of devices used per patient.

LEVEL OF EVIDENCE

Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Psychological morbidity and health-related quality of life after injury: multicentre cohort study

PURPOSE

To demonstrate the impact of psychological morbidity 1 month post-injury on subsequent post-injury quality of life (HRQoL) in a general injury population in the UK to inform development of trauma care and rehabilitation services.

METHODS

Multicentre cohort study of 16-70-year-olds admitted to 4 UK hospitals following injury. Psychological morbidity and HRQoL (EQ-5D-3L) were measured at recruitment and 1, 2, 4 and 12 months post-injury. A reduction in EQ-5D compared to retrospectively assessed pre-injury levels of at least 0.074 was taken as the minimal important difference (MID). Multilevel logistic regression explored relationships between psychological morbidity 1 month post-injury and MID in HRQoL over the 12 months after injury.

RESULTS

A total of 668 adults participated. Follow-up rates were 77% (1 month) and 63% (12 months). Substantial reductions in HRQoL were seen; 93% reported a MID at 1 month and 58% at 12 months. Problems with pain, mobility and usual activities were commonly reported at each time point. Depression and anxiety scores 1 month post-injury were independently associated with subsequent MID in HRQoL. The relationship between depression and HRQoL was partly explained by anxiety and to a lesser extent by pain and social functioning. The relationship between anxiety and HRQoL was not explained by factors measured in our study.

CONCLUSIONS

Hospitalised injuries result in substantial reductions in HRQoL up to 12 months later. Depression and anxiety early in the recovery period are independently associated with lower HRQoL. Identifying and managing these problems, ensuring adequate pain control and facilitating social functioning are key elements in improving HRQoL post-injury.

International Classification of Diseases 10th edition-based disability adjusted life years for measuring of burden of specific injury

Objective

We aimed to develop an International Classification of Diseases (ICD) 10th edition injury code-based disability-adjusted life year (DALY) to measure the burden of specific injuries.

Methods

Three independent panels used novel methods to score disability weights (DWs) of 130 indicator codes sampled from 1,284 ICD injury codes. The DWs were interpolated into the remaining injury codes (n=1,154) to estimate DWs for all ICD injury codes. The reliability of the estimated DWs was evaluated using the test-retest method. We calculated ICD-DALYs for individual injury episodes using the DWs from the Korean National Hospital Discharge Injury Survey (HDIS, n=23,160 of 2004) database and compared them with DALY based on a global burden of disease study (GBD-DALY) regarding validation, correlation, and agreement for 32 injury categories.

Results

Using 130 ICD 10th edition injury indicator codes, three panels determined the DWs using the highest reliability (person trade-off 1, Spearman r=0.724, 0.788, and 0.875 for the three panel groups). The test-retest results for the reliability were excellent (Spearman r=0.932) (P<0.001). The HDIS database revealed injury burden (years) as follows: GBD-DALY (138,548), GBD-years of life disabled (130,481), and GBD-years of life lost (8,117) versus ICD-DALY (262,246), ICD-years of life disabled (255,710), and ICD-years of life lost (6,537), respectively. Spearman’s correlation coefficient of the DALYs between the two methods was 0.759 (P<0.001), and the Bland-Altman test displayed an acceptable agreement, with exception of two categories among 32 injury groups.

Conclusion

The ICD-DALY was developed to calculate the burden of injury for all injury codes and was validated with the GBD-DALY. The ICD-DALY was higher than the GBD-DALY but showed acceptable agreement.

Disability weights based on patient-reported data from a multinational injury cohort

Objective

To create patient-based disability weights for individual injury diagnosis codes and nature-of-injury classifications, for use, as an alternative to panel-based weights, in studies on the burden of disease.

Methods

Self-reported data based on the EQ-5D standardized measure of health status were collected from 29 770 participants in the Injury-VIBES injury cohort study, which covered Australia, the Netherlands, New Zealand, the United Kingdom of Great Britain and Northern Ireland and the United States of America. The data were combined to calculate new disability weights for each common injury classification and for each type of diagnosis covered by the 10th revision of the International statistical classification of diseases and related health problems. Weights were calculated separately for hospital admissions and presentations confined to emergency departments.

Findings

There were 29 770 injury cases with at least one EQ-5D score. The mean age of the participants providing data was 51 years. Most participants were male and almost a third had road traffic injuries. The new disability weights were higher for admitted cases than for cases confined to emergency departments and higher than the corresponding weights used by the Global Burden of Disease 2013 study. Long-term disability was common in most categories of injuries.

Conclusion

Injury is often a chronic disorder and burden of disease estimates should reflect this. Application of the new weights to burden studies would substantially increase estimates of disability-adjusted life-years and provide a more accurate reflection of the impact of injuries on peoples’ lives.

Implications for public health research of models and theories of disability: a scoping study and evidence synthesis

Background

Public health interventions that are effective in the general population are often assumed to apply to people with impairments. However, the evidence to support this is limited and hence there is a need for public health research to take a more explicit account of disability and the perspectives of people with impairments.

Objectives

(1) To examine the literature on theories and models of disability; (2) to assess whether or not, and how, intervention studies of effectiveness could incorporate more inclusive approaches that are consistent with these theories and models; and (3) to use the findings to draw out implications for improving evaluative study designs and evidence-based practice.

Review methods

The project is a scoping review of the literature. The first stage examines theories and models of disability and reflects on possible connections between theories of disability and public health paradigms. This discussion is used to develop an ethical–empirical decision aid/checklist, informed by a human rights approach to disability and ecological approaches to public health. We apply this decision aid in the second stage of the review to evaluate the extent to which the 30 generic public health reviews of interventions and the 30 disability-specific public health interventions include the diverse experiences of disability. Five deliberation panels were also organised to further refine the decision aid: one with health-care professionals and four with politically and socially active disabled people.

Results

The evidence from the review indicated that there has been limited public health engagement with theories and models of disability. Outcome measures were often insensitive to the experiences of disability. Even when disabled people were included, studies rarely engaged with their experiences in any meaningful way. More inclusive research should reflect how people live and ‘flourish’ with disability.

Limitations

The scoping review provides a broad appraisal of a particular field. It generates ideas for future practice rather than a definite framework for action.

Conclusions

Our ethical–empirical decision aid offers a critical framework with which to evaluate current research practice. It also offers a resource for promoting more ethical and evidence-based public health research that is methodologically robust while being sensitive to the experiences of disability.

Future work

Developing more inclusive research and interventions that avoid conceptualising disability as either a ‘burden’ or ‘problem’ is an important starting point. This includes exploring ways of refining and validating current common outcome measures to ensure that they capture a diverse range of disabling experiences, as well as generating evidence on meaningful ways of engaging a broad range of disabled children and adults in the research process.

Funding

The National Institute for Health Research Public Health Research programme.

The measurement of disability weights for 18 prevalent acute poisoning conditions

BACKGROUND

Disability weights (DWs) are used in disease burden studies, with the calculation of the weight of the disability as years lived with disability versus years of lost life accounting for mortalities. Currently, there is a single DW score available for poisoning, which is considered to be a single health state. This makes it difficult to evaluate the differing burdens of poisonings involving various substances/conditions in comparison with other health states in countries with different patterns of substance abuse. The aim of this study is therefore to estimate the DWs of 18 common poisonings based on the expert elicitation method.

METHODS

A panel of 10 medical clinicians who were familiar with the clinical aspects of different poisonings estimated the DWs of 50 health states by interpolating them on a calibrated Visual Analogue Scale. The DWs of some poisonings, such as alcohol, cannabis and heroin, had been estimated in previous studies and so were used to determine the external consistency of our panel. As a matter of routine, the DWs could vary on a scale between 0 (best health state) and 1 (worst health state).

RESULTS

Statistical analysis showed that both the internal (Cronbach's α = 0.912) and external consistency of the panel were acceptable. The DWs for the different poisonings were estimated along a range from 0.830 for severe aluminium phosphide to 0.022 for mild benzodiazepine.

CONCLUSIONS

Different poisonings should be weighted differently since they vary widely. Unfortunately, they are currently all weighted the same.

Burden of road traffic injuries: Disability-adjusted life years in relation to hospitalization and the maximum abbreviated injury scale

BACKGROUND

The consequences of non-fatal road traffic injuries (RTI) are increasingly adopted by policy makers as an indicator of traffic safety. However, it is not agreed upon which level of severity should be used as cut-off point for assessing road safety performance. Internationally, within road safety, injury severity is assessed by means of the maximum abbreviated injury scale (MAIS). The choice for a severity cut-off point highly influences the measured disease burden of RTI. This paper assesses the burden of RTI in terms of disability adjusted life years (DALYs) by hospitalization status and MAIS cut-off point in the Netherlands.

METHODS

Hospital discharge register (HDR) and emergency department (ED) data for RTI in the Netherlands were selected for the years 2007-2009, as well as mortality data. The incidence, years lived with disability (YLD), years of life lost (YLL) owing to premature death, and DALYs were calculated. YLD for admitted patients was subdivided by MAIS severity levels.

RESULTS

RTI resulted in 48,500 YLD and 27,900 YLL respectively, amounting to 76,400 DALYs per year in the Netherlands. The largest proportion of DALYs is related to fatalities (37%), followed by admitted MAIS 2 injuries (25%), ED treated injuries (16%) and admitted MAIS 3+ injuries (18%). Admitted MAIS 1 injuries only account for a small fraction of DALYs (4%). In the Netherlands, the diseases burden of RTI is highest among cyclists with 39% of total DALYs. One half of all bicycle related DALYs are attributable to admitted MAIS 2+ injuries, but ED treated injuries also account for a large proportion of DALYs in this group (28%). Car occupants are responsible for 26% of all DALYs, primarily caused by fatalities (66%), followed by admitted MAIS 2+ injuries (25%). ED treated injuries only account for 5% of DALYs in this group.

CONCLUSIONS

When using admitted MAIS 3+ or admitted MAIS 2+ as severity cut-off point, 54% and 80% of all DALYs are captured respectively. Assessing the influence of different severity cut-off points by MAIS on the proportion and number of DALYs captured gives valuable information for guiding choices on the definition of serious RTI.

The burden of Lyme borreliosis expressed in disability-adjusted life years

BACKGROUND

Lyme borreliosis (LB) is the most commonly reported tick-borne infection in Europe and North America. In the last 15 years a 3-fold increase was observed in general practitioner consultations for LB in the Netherlands. To support prioritization of prevention and control efforts for LB, we estimated its burden expressed in Disability-Adjusted Life Years (DALYs).

METHODS

We used available incidence estimates for three LB outcomes: (i) erythema migrans (EM), (ii) disseminated LB and (iii) Lyme-related persisting symptoms. To generate DALYs, disability weights and duration per outcome were derived using a patient questionnaire including health-related quality of life as measured by the EQ-5D.

RESULTS

We estimated the total LB burden for the Netherlands in 2010 at 10.55 DALYs per 100,000 population (95% CI: 8.80-12.43); i.e. 0.60 DALYs for EM, 0.86 DALYs for disseminated LB and 9.09 DALYs for Lyme-related persisting symptoms. Per patient this was 0.005 DALYs for EM, 0.113 for disseminated LB and 1.661 DALYs for a patient with Lyme-related persisting symptoms. In a sensitivity analysis the total LB burden ranged from 7.58 to 16.93 DALYs per 100,000 population.

CONCLUSIONS

LB causes a substantial disease burden in the Netherlands. The vast majority of this burden is caused by patients with Lyme-related persisting symptoms. EM and disseminated Lyme have a more modest impact. Further research should focus on the mechanisms that trigger development of these persisting symptoms that patients and their physicians attribute to LB.

Reduced population burden of road transport-related major trauma after introduction of an inclusive trauma system

This population-based study found that since the introduction of an inclusive, regionalized trauma system in Victoria, Australia, the burden of road transport–related serious injury has decreased. Hospitalized major trauma cases increased, but disability burden per case declined. Increased survival did not result in an overall increase in nonfatal injury burden.

Objective:

To describe the burden of road transport–related serious injury in Victoria, Australia, over a 10-year period, after the introduction of an integrated trauma system.

Background:

Road traffic injury is a leading cause of death and disability worldwide. Efforts to improve care of the injured are important for reducing burden, but the impact of trauma care systems on burden and cost of road traffic injury has not been evaluated.

Methods:

All road transport–related deaths and major trauma (injury severity score >12) cases were extracted from population-based coroner and trauma registry data sets for July 2001 to June 2011. Modeling was used to assess changes in population incidence rates and odds of in-hospital mortality. Disability-adjusted life years, combining years of life lost and years lived with disability, were calculated. Cost of health loss was calculated from estimates of the value of a disability-adjusted life year.

Results:

Incidence of road transport–related deaths decreased (incidence rate ratio 0.95, 95% confidence interval: 0.94–0.96), whereas the incidence of hospitalized major trauma increased (incidence rate ratio 1.03, 95% confidence interval: 1.02–1.04). Years of life lost decreased by 43%, and years lived with disability increased by 32%, with an overall 28% reduction in disability-adjusted life years over the decade. There was a cost saving per case of A$633,446 in 2010–2011 compared with the 2001–2002 financial year.

Conclusions:

Since introduction of the trauma system in Victoria, Australia, the burden of road transport–related serious injury has decreased. Hospitalized major trauma cases increased, whereas disability burden per case declined. Increased survival does not necessarily result in an overall increase in nonfatal injury burden.

Review of disability weight studies: comparison of methodological choices and values

INTRODUCTION

The disability-adjusted life year (DALY) is widely used to assess the burden of different health problems and risk factors. The disability weight, a value anchored between 0 (perfect health) and 1 (equivalent to death), is necessary to estimate the disability component (years lived with disability, YLDs) of the DALY. After publication of the ground-breaking Global Burden of Disease (GBD) 1996, alternative sets of disability weights have been developed over the past 16 years, each using different approaches with regards to the panel, health state description, and valuation methods. The objective of this study was to review all studies that developed disability weights and to critically assess the methodological design choices (health state and time description, panel composition, and valuation method). Furthermore, disability weights of eight specific conditions were compared.

METHODS

Disability weights studies (1990¿2012) in international peer-reviewed journals and grey literature were identified with main inclusion criteria being that the study assessed DALY disability weights for several conditions or a specific group of illnesses. Studies were collated by design and methods and evaluation of results.

RESULTS

Twenty-two studies met the inclusion criteria of our review. There is considerable variation in methods used to derive disability weights, although most studies used a disease-specific description of the health state, a panel that consisted of medical experts, and nonpreference-based valuation method to assess the values for the majority of the disability weights. Comparisons of disability weights across 15 specific disease and injury groups showed that the subdivision of a disease into separate health states (stages) differed markedly across studies. Additionally, weights for similar health states differed, particularly in the case of mild diseases, for which the disability weight differed by a factor of two or more.

CONCLUSIONS

In terms of comparability of the resulting YLDs, the global use of the same set of disability weights has advantages, though practical constraints and intercultural differences should be taken into account into such a set.

Validating and Improving Injury Burden Estimates Study: the Injury-VIBES study protocol

BACKGROUND

Priority setting, identification of unmet and changing healthcare needs, service and policy planning, and the capacity to evaluate the impact of health interventions requires valid and reliable methods for quantifying disease and injury burden. The methodology developed for the Global Burden of Disease (GBD) studies has been adopted to estimate the burden of disease in national, regional and global projects. However, there has been little validation of the methods for estimating injury burden using empirical data.

OBJECTIVE

To provide valid estimates of the burden of non-fatal injury using empirical data.

SETTING

Data from prospective cohort studies of injury outcomes undertaken in the UK, USA, Australia, New Zealand and The Netherlands.

DESIGN AND PARTICIPANTS

Meta-analysis of deidentified, patient-level data from over 40 000 injured participants in six prospective cohort studies: Victorian State Trauma Registry, Victorian Orthopaedic Trauma Outcomes Registry, UK Burden of Injury study, Prospective Outcomes of Injury study, National Study on Costs and Outcomes of Trauma and the Dutch Injury Patient Survey.

ANALYSIS

Data will be systematically analysed to evaluate and refine injury classification, development of disability weights, establishing the duration of disability and handling of cases with more than one injury in burden estimates. Developed methods will be applied to incidence data to compare and contrast various methods for estimating non-fatal injury burden.

CONTRIBUTION TO THE FIELD

The findings of this international collaboration have the capacity to drive how injury burden is measured for future GBD estimates and for individual country or region-specific studies.

Common values in assessing health outcomes from disease and injury: disability weights measurement study for the Global Burden of Disease Study 2010

BACKGROUND

Measurement of the global burden of disease with disability-adjusted life-years (DALYs) requires disability weights that quantify health losses for all non-fatal consequences of disease and injury. There has been extensive debate about a range of conceptual and methodological issues concerning the definition and measurement of these weights. Our primary objective was a comprehensive re-estimation of disability weights for the Global Burden of Disease Study 2010 through a large-scale empirical investigation in which judgments about health losses associated with many causes of disease and injury were elicited from the general public in diverse communities through a new, standardised approach.

METHODS

We surveyed respondents in two ways: household surveys of adults aged 18 years or older (face-to-face interviews in Bangladesh, Indonesia, Peru, and Tanzania; telephone interviews in the USA) between Oct 28, 2009, and June 23, 2010; and an open-access web-based survey between July 26, 2010, and May 16, 2011. The surveys used paired comparison questions, in which respondents considered two hypothetical individuals with different, randomly selected health states and indicated which person they regarded as healthier. The web survey added questions about population health equivalence, which compared the overall health benefits of different life-saving or disease-prevention programmes. We analysed paired comparison responses with probit regression analysis on all 220 unique states in the study. We used results from the population health equivalence responses to anchor the results from the paired comparisons on the disability weight scale from 0 (implying no loss of health) to 1 (implying a health loss equivalent to death). Additionally, we compared new disability weights with those used in WHO's most recent update of the Global Burden of Disease Study for 2004.

FINDINGS

13,902 individuals participated in household surveys and 16,328 in the web survey. Analysis of paired comparison responses indicated a high degree of consistency across surveys: correlations between individual survey results and results from analysis of the pooled dataset were 0·9 or higher in all surveys except in Bangladesh (r=0·75). Most of the 220 disability weights were located on the mild end of the severity scale, with 58 (26%) having weights below 0·05. Five (11%) states had weights below 0·01, such as mild anaemia, mild hearing or vision loss, and secondary infertility. The health states with the highest disability weights were acute schizophrenia (0·76) and severe multiple sclerosis (0·71). We identified a broad pattern of agreement between the old and new weights (r=0·70), particularly in the moderate-to-severe range. However, in the mild range below 0·2, many states had significantly lower weights in our study than previously.

INTERPRETATION

This study represents the most extensive empirical effort as yet to measure disability weights. By contrast with the popular hypothesis that disability assessments vary widely across samples with different cultural environments, we have reported strong evidence of highly consistent results.

FUNDING

Bill & Melinda Gates Foundation.

Burden of disease resulting from chronic mountain sickness among young Chinese male immigrants in Tibet

Background

In young Chinese men of the highland immigrant population, chronic mountain sickness (CMS) is a major public health problem. The aim of this study was to measure the disease burden of CMS in this population.

Methods

We used disability-adjusted life years (DALYs) to estimate the disease burden of CMS. Disability weights were derived using the person trade-off methodology. CMS diagnoses, symptom severity, and individual characteristics were obtained from surveys collected in Tibet in 2009 and 2010. The DALYs of individual patients and the DALYs/1,000 were calculated.

Results

Disability weights were obtained for 21 CMS health stages. The results of the analyses of the two surveys were consistent with each other. At different altitudes, the CMS rates ranged from 2.1-37.4%; the individual DALYs of patients ranged from 0.13-0.33, and the DALYs/1,000 ranged from 3.60-52.78. The age, highland service years, blood pressure, heart rate, smoking rate, and proportion of the sample working in engineering or construction were significantly higher in the CMS group than in the non-CMS group (p < 0.05). These variables were also positively associated with the individual DALYs (p < 0.05). Among the symptoms, headaches caused the largest proportion of DALYs.

Conclusion

The results show that CMS imposes a considerable burden on Chinese immigrants to Tibet. Immigrants with characteristics such as a higher residential altitude, more advanced age, longer highland service years, being a smoker, and working in engineering or construction were more likely to develop CMS and to increase the disease burden. Higher blood pressure and heart rate as a result of CMS were also positively associated with the disease burden. The authorities should pay attention to the highland disease burden and support the development and application of DALYs studies of CMS and other highland diseases.

Epidemiological burden of minor, major and fatal trauma in a national injury pyramid

BACKGROUND

The impact of trauma on population health is underestimated because comprehensive overviews of the entire severity spectrum of injuries are scarce. The aim of this study was to measure the total health impact of fatal and non-fatal unintentional injury in the Netherlands.

METHODS

Epidemiological data for the four levels of the injury pyramid (general practitioner (GP) registry, emergency department (ED) registers, hospital discharge and mortality data) were obtained for the whole country. For all levels, the incidence and years of life lost (YLL) owing to premature death, years lived with disability (YLD) and disability-adjusted life-years (DALYs) were calculated.

RESULTS

Unintentional injury resulted in 67 547 YLL and 161 775 YLD respectively, amounting to 229 322 DALYs (14.1 per 1000 inhabitants). Home and leisure, and traffic injuries caused most DALYs. Minor injury (GP and ED treatment) contributed 37.3 per cent (85 504 DALYs; 5.2 per 1000) to the total burden of injury, whereas injuries requiring hospital admission contributed 33.3 per cent (76 271 DALYs; 4.7 per 1000) and fatalities contributed 29.5 per cent (67 547 DALYs; 4.1 per 1000). Men aged 15-65 years had the greatest burden of injury, resulting in a share of 39.6 per cent for total DALYs owing to unintentional injury. The highest individual burden resulted from death (19 DALYs per patient).

CONCLUSION

Trauma causes a major burden to society. For priority setting in public health and the identification of opportunities for prevention it is important that burden-of-injury estimates cover the entire spectrum of injuries, ranging from minor injury to death.

Improved and standardized method for assessing years lived with disability after injury

OBJECTIVE

To develop a standardized method for calculating years lived with disability (YLD) after injury.

METHODS

The method developed consists of obtaining data on injury cases seen in emergency departments as well as injury-related hospital admissions, using the EUROCOST system to link the injury cases to disability information and employing empirical data to describe functional outcomes in injured patients.

FINDINGS

Overall, 87 weights and proportions for 27 injury diagnoses involving lifelong consequences were included in the method. Almost all of the injuries investigated (96-100%) could be assigned to EUROCOST categories. The mean number of YLD per case of injury varied with the country studied. Use of the novel method resulted in estimated burdens of injury that were 3 to 8 times higher, in terms of YLD, than the corresponding estimates produced using the conventional methods employed in global burden of disease studies, which employ disability-adjusted life years.

CONCLUSION

The novel method for calculating YLD after injury can be applied in different settings, overcomes some limitations of the method used to calculate the global burden of disease, and allows more accurate estimates of the population burden of injury.

Measuring the population burden of injuries--implications for global and national estimates: a multi-centre prospective UK longitudinal study

BACKGROUND

Current methods of measuring the population burden of injuries rely on many assumptions and limited data available to the global burden of diseases (GBD) studies. The aim of this study was to compare the population burden of injuries using different approaches from the UK Burden of Injury (UKBOI) and GBD studies.

METHODS AND FINDINGS

The UKBOI was a prospective cohort of 1,517 injured individuals that collected patient-reported outcomes. Extrapolated outcome data were combined with multiple sources of morbidity and mortality data to derive population metrics of the burden of injury in the UK. Participants were injured patients recruited from hospitals in four UK cities and towns: Swansea, Nottingham, Bristol, and Guildford, between September 2005 and April 2007. Patient-reported changes in quality of life using the EQ-5D at baseline, 1, 4, and 12 months after injury provided disability weights used to calculate the years lived with disability (YLDs) component of disability adjusted life years (DALYs). DALYs were calculated for the UK and extrapolated to global estimates using both UKBOI and GBD disability weights. Estimated numbers (and rates per 100,000) for UK population extrapolations were 750,999 (1,240) for hospital admissions, 7,982,947 (13,339) for emergency department (ED) attendances, and 22,185 (36.8) for injury-related deaths in 2005. Nonadmitted ED-treated injuries accounted for 67% of YLDs. Estimates for UK DALYs amounted to 1,771,486 (82% due to YLDs), compared with 669,822 (52% due to YLDs) using the GBD approach. Extrapolating patient-derived disability weights to GBD estimates would increase injury-related DALYs 2.6-fold.

CONCLUSIONS

The use of disability weights derived from patient experiences combined with additional morbidity data on ED-treated patients and inpatients suggests that the absolute burden of injury is higher than previously estimated. These findings have substantial implications for improving measurement of the national and global burden of injury.

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.