Effects of Reductions in Body Mass Index on the Future Osteoarthritis Burden in Canada: A Population-Based Microsimulation Study

The burden of osteoarthritis due to high Body Mass Index in Iran from 1990 to 2019

High BMI related burden of knee and hip osteoarthritis (OA) is on a significant rise worldwide. OA not only causes joint pain and stiffness, but it also leads to disability. This study investigated the trend and burden of OA attributable to high body mass index (BMI) in Iran. The age-standardized disability-adjusted life years (DALYs) rates of knee and hip OA due to high BMI, were estimated using data from the Global Burden of Disease 2019. We evaluated DALYs rate trend of high BMI related OA by sex and age in span of 30 years from 1990-2019 across the 31 provinces of Iran. The age-standardized prevalence trend of OA in the knee and hip showed an increase from 1990 to 2019. In 2019 there were 29.92 (95% CI: 10.98-64.92) and 42.50 (95% CI: 16.32-97.37) DALYs/100,000 related to OA from high BMI in men and women, respectively. 2019 saw the greatest DALYs/100,000 rate in the 65-79 age group. From 2005 to 2019, men and women saw DALYs/100,000 rate changes of 24.87 and 17.43 percent, respectively. The burden of knee OA was significantly higher than that of hip OA. DALYs rate of OA due to high BMI was found to be positively associated with the Socio-demographic Index (SDI). The burden of knee and hip OA due to high BMI has increased significantly in recent years in Iran among all age groups of both men and women. It is recommended that health policymakers develop weight control strategies to reduce the burden of OA and implement them at the national level.

A comparison of three strategies to reduce the burden of osteoarthritis: A population-based microsimulation study

Objectives

The purpose of this study was to compare three strategies for reducing population health burden of osteoarthritis (OA): improved pharmacological treatment of OA-related pain, improved access to joint replacement surgery, and prevention of OA by reducing obesity and overweight.

Methods

We applied a validated computer microsimulation model of OA in Canada. The model simulated a Canadian-representative open population aged 20 years and older. Variables in the model included demographics, body mass index, OA diagnosis, OA treatment, mortality, and health-related quality of life. Model parameters were derived from analyses of national surveys, population-based administrative data, a hospital-based cohort study, and the literature. We compared 8 what-if intervention scenarios in terms of disability-adjusted life years (DALYs) relative to base-case, over a wide range of time horizons.

Results

Reductions in DALYs depended on the type of intervention, magnitude of the intervention, and the time horizon. Medical interventions (a targeted increase in the use of painkillers) tended to produce effects quickly and were, therefore, most effective over a short time horizon (a decade). Surgical interventions (increased access to joint replacement) were most effective over a medium time horizon (two decades or longer). Preventive interventions required a substantial change in BMI to generate a significant impact, but produced more reduction in DALYs than treatment strategies over a very long time horizon (several decades).

Conclusions

In this population-based modeling study we assessed the potential impact of three different burden reduction strategies in OA. Data generated by our model may help inform the implementation of strategies to reduce the burden of OA in Canada and elsewhere.

Modeling the natural history of fatty liver using lifestyle-related risk factors: Effects of body mass index (BMI) on the life-course of fatty liver

Background

Incident fatty liver increases the risk of non–alcoholic fatty liver disease (NAFLD), which may lead to end-stage liver diseases, and increase the risk of cardiovascular disease and diabetes. For its prevention, modeling the natural history of fatty liver is useful to demonstrate which lifestyle-related risk factors (e.g. body mass index and cholesterol) play the greatest role in the life-course of fatty liver.

Methods

Model predictors and their predictive algorithms were determined by prospective regression analyses using 5–year data from approximately 2000 Japanese men aged 20–69 years. The participants underwent health examinations and completed questionnaires on their lifestyle behaviors annually from 2012 to 2016. The life–course of fatty liver was simulated based on this participant data using Monte Carlo simulation methods. Sensitivity analyses were performed. The validity of the model was discussed.

Results

The body mass index (BMI) and low–density/high–density lipoprotein cholesterol (LDL–C/HDL–C) ratio significantly aided in predicting incident fatty liver. When the natural history of fatty liver was simulated using the data of participants aged 30–39 years, the prevalence increased from 20% to 32% at 40–59 years before decreasing to 24% at 70–79 years. When annual updates of BMI and LDL–C/HDL–C ratio decreased/increased by 1%, the peak prevalence of fatty liver (32%) changed by −8.0/10.7% and −1.6/1.4%, respectively.

Conclusions

We modeled the natural history of fatty liver for adult Japanese men. The model includes BMI and LDL‒C/HDL‒C ratio, which played a significant role in predicting the presence of fatty liver. Specifically, annual changes in BMI of individuals more strongly affected the life‒course of fatty liver than those in the LDL–C/HDL–C ratio. Sustainable BMI control for individuals may be the most effective option for preventing fatty liver in a population.

A Model of Care for Osteoarthritis of the Hip and Knee: Development of a System-Wide Plan for the Health Sector in Victoria, Australia

Osteoarthritis (OA) imposes a significant burden to the person, the health system and the community. Models of Care (MoCs) drive translation of evidence into policy and practice and provide a platform for health system reform. The Victorian MoC for OA of the hip and knee was developed following a best-practice framework, informed by best-evidence and iterative cross-sector consultation, including direct consumer consultation. Governance and external expert advisory committees consisting of local OA care champions facilitated the development and consultation processes. The MoC outlines key components of care, care that is not recommended, and suggests phased implementation strategies. This paper describes the MoC development process and lessons learned.

Development and validation of a new population-based simulation model of osteoarthritis in New Zealand

OBJECTIVE

To describe the construction and preliminary validation of a new population-based microsimulation model developed to analyse the health and economic burden and cost-effectiveness of treatments for knee osteoarthritis (OA) in New Zealand (NZ).

METHOD

We developed the New Zealand Management of Osteoarthritis (NZ-MOA) model, a discrete-time state-transition microsimulation model of the natural history of radiographic knee OA. In this article, we report on the model structure, derivation of input data, validation of baseline model parameters against external data sources, and validation of model outputs by comparison of the predicted population health loss with previous estimates.

RESULTS

The NZ-MOA model simulates both the structural progression of radiographic knee OA and the stochastic development of multiple disease symptoms. Input parameters were sourced from NZ population-based data where possible, and from international sources where NZ-specific data were not available. The predicted distributions of structural OA severity and health utility detriments associated with OA were externally validated against other sources of evidence, and uncertainty resulting from key input parameters was quantified. The resulting lifetime and current population health-loss burden was consistent with estimates of previous studies.

CONCLUSION

The new NZ-MOA model provides reliable estimates of the health loss associated with knee OA in the NZ population. The model structure is suitable for analysis of the effects of a range of potential treatments, and will be used in future work to evaluate the cost-effectiveness of recommended interventions within the NZ healthcare system.

Distribution and Drivers of Average Direct Cost of Osteoarthritis in Canada From 2003 to 2010

OBJECTIVE

To estimate the distribution and drivers of the average direct cost of osteoarthritis (OA) in Canada using a population-based health microsimulation model of OA from 2003 to 2010.

METHODS

We used a previously published microsimulation model to estimate the distribution of average cost of OA across different cost components and OA stages. OA stages were defined according to the patient flow within the health care system. Cost components associated with pharmacologic and nonpharmacologic treatments, physician visits, and hospitalization were included. Scenario analysis was performed to evaluate average cost drivers from 2003 to 2010.

RESULTS

During the study period, the OA population size grew from 2.9 to 3.6 million, while the average cost increased from $577 to $811 (Canadian) per patient per year. The highest increase in share of cost components was for total joint replacement (TJR) surgery (24% to 32%). The highest average cost was incurred by patients in stage 4 (during and after revision surgery), while around 80% of OA patients were in stage 1 (OA diagnosed but has not visited an orthopedic surgeon). Increase in the proportion of OA patients receiving TJR surgeries (34%) and price inflation (29%) were the most significant drivers of average cost.

CONCLUSION

The average cost of OA has been increasing during the study period mostly due to an increase in the proportion of patients receiving TJR surgeries and price inflation. The distribution of average cost of OA across disease stages needs to be considered when designing policies targeting specific aspects of OA care.

Alzheimer's and other dementias in Canada, 2011 to 2031: a microsimulation Population Health Modeling (POHEM) study of projected prevalence, health burden, health services, and caregiving use

BACKGROUND

Worldwide, there is concern that increases in the prevalence of dementia will result in large demands for caregivers and supportive services that will be challenging to address. Previous dementia projections have either been simple extrapolations of prevalence or macrosimulations based on dementia incidence.

METHODS

A population-based microsimulation model of Alzheimer's and related dementias (POHEM:Neurological) was created using Canadian demographic data, estimates of dementia incidence, health status (health-related quality of life and mortality risk), health care costs and informal caregiving use. Dementia prevalence and 12 other measures were projected to 2031.

RESULTS

Between 2011 and 2031, there was a projected two-fold increase in the number of people living with dementia in Canada (1.6-fold increase in prevalence rate). By 2031, the projected informal (unpaid) caregiving for dementia in Canada was two billion hours per year, or 100 h per year per Canadian of working age.

CONCLUSIONS

The projected increase in dementia prevalence was largely related to the expected increase in older Canadians, with projections sensitive to changes in the age of dementia onset.