Projecting the direct cost burden of osteoarthritis in Canada using a microsimulation model.

OBJECTIVES: To estimate the future direct cost of OA in Canada using a population-based health microsimulation model of osteoarthritis (POHEM-OA). METHODS: We used administrative health data from the province of British Columbia (BC), Canada, a survey of a random sample of BC residents diagnosed with OA (Ministry of Health of BC data), Canadian Institute of Health Information (CIHI) cost data and literature estimates to populate a microsimulation model. Cost components associated with pharmacological and non-pharmacological treatments, total joint replacement (TJR) surgery, as well as use of hospital resources and management of complications arising from the treatment of osteoarthritis (OA) were included. Future costs were then simulated using the POHEM-OA model to construct profiles for each adult Canadian. RESULTS: From 2010 to 2031, as the prevalence of OA is projected to increase from 13.8% to 18.6%, the total direct cost of OA is projected to increase from $2.9 billion to $7.6 billion, an almost 2.6-fold increase (in 2010 $CAD). From the highest to the lowest, the cost components that will constitute the total direct cost of OA in 2031 are hospitalization cost ($2.9 billion), outpatient services ($1.2 billion), alternative care and out-of-pocket cost categories ($1.2 billion), drugs ($1 billion), rehabilitation ($0.7 billion) and side-effect of drugs ($0.6 billion). CONCLUSIONS: Projecting the future trends in the cost of OA enables policy makers to anticipate the significant shifts in its distribution of burden in the future.

Intentional injury hospitalizations in geographical areas with a high percentage of Aboriginal-identity residents, 2004/2005 to 2009/2010.

INTRODUCTION: This study describes rates of self-inflicted and assault-related injury hospitalizations in areas with a relatively high percentage of residents identifying as First Nations, Métis and Inuit, by injury cause, age group and sex. METHODS: All separation records from acute in-patient hospitals for Canadian provinces and territories excluding Quebec were obtained from the Discharge Abstract Database. Dissemination areas with more than 33% of residents reporting an Aboriginal identity in the 2006 Census were categorized as high-percentage Aboriginal-identity areas. RESULTS: Overall, in high-percentage Aboriginal-identity areas, age-standardized hospitalization rates (ASHRs) for self-inflicted injuries were higher among females, while ASHRs for assault-related injuries were higher among males. Residents of high-percentage Aboriginal-identity areas were at least three times more likely to be hospitalized due to a self-inflicted injury and at least five times more likely to be hospitalized due to an assault-related injury compared with those living in low-percentage Aboriginal-identity areas. CONCLUSION: Future research should examine co-morbidities, socio-economic conditions and individual risk behaviours as factors associated with intentional injury hospitalizations.

TITRE: Hospitalisations pour blessures intentionnelles dans les régions à fort pourcentage de résidents d'identité autochtone, 2004-2005 à 2009-2010. INTRODUCTION: Cette étude décrit les taux d'hospitalisation pour blessures auto-infligées et pour blessures par agression dans les régions à pourcentage relativement élevé de résidents s'identifiant comme membres des Premières nations, Métis ou Inuits, par cause de blessure, par tranche d'âge et par sexe. MÉTHODOLOGIE: Tous les dossiers de sortie des hôpitaux de soins de courte durée des provinces et territoires du Canada hors Québec ont été tirés de la Base de données sur les congés des patients. Les aires de diffusion où plus de 33 % des résidents ont déclaré appartenir à un groupe autochtone au recensement de 2006 ont été classées comme « régions à fort pourcentage d'Autochtones ¼. RÉSULTATS: Dans l'ensemble, dans les régions à fort pourcentage d'Autochtones, les taux d'hospitalisation normalisés selon l'âge (THNA) pour blessures auto-infligées étaient plus élevés chez les femmes, tandis que les THNA pour blessures par agression étaient plus élevés chez les hommes. Comparativement aux résidents des régions à faible pourcentage d'Autochtones, les résidents des régions à fort pourcentage d'Autochtones étaient au moins trois fois plus susceptibles d'avoir été hospitalisés pour blessures autoinfligées et au moins cinq fois plus susceptibles d'avoir été hospitalisés pour blessures par agression. CONCLUSION: Les recherches à venir devraient analyser les comorbidités et les conditions socioéconomiques ainsi que les comportements à risque individuels comme facteurs associés à l'hospitalisation pour blessures auto-infligées.

Hospitalizations for unintentional injuries among Canadian adults in areas with a high percentage of Aboriginal-identity residents.

INTRODUCTION: Injuries are a leading cause of death and morbidity. While individual Aboriginal identifiers are not routinely available on national administrative databases, this study examines unintentional injury hospitalization, by cause, in areas with a high percentage of Aboriginal-identity residents. METHODS: Age-standardized hospitalization rates (ASHRs) and rate ratios were calculated based on 2004/2005-2009/2010 data from the Discharge Abstract Database. RESULTS: Falls were the most frequent cause of injury. For both sexes, ASHRs were highest in high-percentage First Nations-identity areas; high-percentage Métis-identity areas presented the highest overall ASHR among men aged 20-29 years, and high-percentage Inuit-identity areas presented the lowest ASHRs among men of all age groups. Some causes, such as falls, presented a high ASHR but a rate ratio similar to that for all causes combined; other causes, such as firearm injuries among men in high-percentage First Nations-identity areas, presented a relatively low ASHR but a high rate ratio. Residents of high-percentage Aboriginal-identity areas have a higher ASHR for hospitalization for injuries than residents of low-percentage Aboriginal-identity areas. CONCLUSION: Residents of high-percentage Aboriginal-identity areas also live in areas of lower socio-economic conditions, suggesting that the causes for rate differences among areas require further investigation.

TITRE: Hospitalisations pour blessures non intentionnelles chez les adultes au Canada, dans les régions ayant un fort pourcentage de résidents d'identité autochtone. INTRODUCTION: Les blessures constituent une cause importante de décès et de morbidité. Bien qu'aucun indicateur d'identité autochtone ne soit directement disponible dans les bases de données administratives nationales, cette étude porte sur les hospitalisations pour blessure non intentionnelle, selon la cause, dans les régions ayant un fort pourcentage de résidents d'identité autochtone. MÉTHODOLOGIE: Nous avons calculé les taux d'hospitalisation normalisés selon l'âge (THNA) et les rapports de taux pour 2004-2005 à 2009-2010, à partir de la Base de données sur les congés des patients. RÉSULTATS: Les chutes étaient la cause principale de blessure. Les THNA étaient plus élevés pour les hommes comme pour les femmes dans les régions ayant un fort pourcentage de membres des Premières nations; dans les régions ayant un fort pourcentage de Métis, c'est chez les hommes de 20 à 29 ans que le THNA global était le plus élevé, tandis qu'il était le plus bas chez les hommes de tous les groupes d'âge dans les régions à fort pourcentage d'Inuits. Certaines causes, telles que les chutes, étaient associées à un THNA élevé mais avec un rapport de taux semblable à celui observé pour toutes causes confondues; d'autres causes, comme les blessures par arme à feu chez les hommes dans les régions à fort pourcentage de membres des Premières nations, présentaient un THNA relativement faible mais un rapport de taux élevé. Les résidents des régions à fort pourcentage d'Autochtones présentaient un THNA pour blessure plus élevé que ceux des régions à faible pourcentage d'Autochtones. CONCLUSION: Les résidents des régions à fort pourcentage d'Autochtones vivent dans des régions dont le statut socioéconomique était faible, ce qui invite à une recherche plus approfondie à propos des différences de taux entre régions.

Development of a population-based microsimulation model of osteoarthritis in Canada.

OBJECTIVES: The purpose of the study was to develop a population-based simulation model of osteoarthritis (OA) in Canada that can be used to quantify the future health and economic burden of OA under a range of scenarios for changes in the OA risk factors and treatments. In this article we describe the overall structure of the model, sources of data, derivation of key input parameters for the epidemiological component of the model, and preliminary validation studies. DESIGN: We used the Population Health Model (POHEM) platform to develop a stochastic continuous-time microsimulation model of physician-diagnosed OA. Incidence rates were calibrated to agree with administrative data for the province of British Columbia, Canada. The effect of obesity on OA incidence and the impact of OA on health-related quality of life (HRQL) were modeled using Canadian national surveys. RESULTS: Incidence rates of OA in the model increase approximately linearly with age in both sexes between the ages of 50 and 80 and plateau in the very old. In those aged 50+, the rates are substantially higher in women. At baseline, the prevalence of OA is 11.5%, 13.6% in women and 9.3% in men. The OA hazard ratios for obesity are 2.0 in women and 1.7 in men. The effect of OA diagnosis on HRQL, as measured by the Health Utilities Index Mark 3 (HUI3), is to reduce it by 0.10 in women and 0.14 in men. CONCLUSIONS: We describe the development of the first population-based microsimulation model of OA. Strengths of this model include the use of large population databases to derive the key parameters and the application of modern microsimulation technology. Limitations of the model reflect the limitations of administrative and survey data and gaps in the epidemiological and HRQL literature.

Coeur en santé St-Henri--a heart health promotion programme in Montreal, Canada: design and methods for evaluation.

STUDY OBJECTIVE: This paper describes the objectives, design, and methods of evaluation of the impact of the coeur en santé St-Henri programme, as well as selected results from the evaluation to date. It discusses the possible effects of study design choices made to maintain the impact evaluation within budget. DESIGN: The impact of the programme is evaluated in a community trial which compares the prevalence of cardiovascular disease behavioural risk factors before and after programme implementation in the intervention and a matched comparison community, in both longitudinal cohort and independent sample surveys. In addition, repeated independent sample surveys are conducted in the intervention community to monitor awareness of and participation in the programme. PARTICIPANTS: The baseline sample for both the longitudinal cohort and independent sample surveys included 849 subjects from the intervention community (79.3% of 1071 eligible subjects--8.0% could not be contacted and 12.6% refused) and 825 subjects from the comparison community (77.8% of 1066 eligible subjects--6.6% could not be contacted and 15.6% refused). The two surveys on awareness and participation conducted to date, included 461 (71.0% of 649 eligible subjects) and 387 (67.9% of 570 eligible subjects) subjects respectively from the intervention community. MEASUREMENTS: Baseline data for the longitudinal cohort and independent sample surveys on behavioural risk factor outcomes including use of tobacco, physical activity behaviour, high fat diet, and behaviours related to blood pressure and cholesterol control were collected in 35 minute telephone interviews in both the intervention and comparison communities. Data on awareness of and participation in the programme were collected in 10 minute interviews in the intervention community only in two independent sample surveys conducted seven and 22 months respectively after the baseline survey. RESULTS: With the exception of smoking, the intervention and comparison communities were similar at baseline with regard to the prevalence of behavioural risk factors studied. Awareness of the coeur en santé programme increased from 64.1% in January 1993 to 72.9% 15 months later. Participation in the programme increased from 21.3% to 33.7%. CONCLUSIONS: This paper presents background information on the evaluation of the impact of the coeur en santé programme, as a reference for future publications.

The prognostic consequences in the making of the initial medical diagnosis of work-related back injuries.

STUDY DESIGN: A cohort of 1848 workers, representative of all sectors of industry, who were compensated for a low back injury in 1988 but not in the previous 2 years, was followed over 24 months. OBJECTIVES: To determine the prognostic value of the physician's initial diagnosis of back problems. SUMMARY OF BACKGROUND DATA: In the absence of a standardized classification of diagnoses of back pain, this study aimed to provide an element of validity to a classification previously proposed that consists of "specific" and "nonspecific" back pain. METHODS: Medical charts were reviewed at the Quebec Worker's Compensation Board to extract the diagnosis made by the treating physicians within 7 days of the first day of absence from work. Diagnoses were categorized into "specific" (lesions of vertebrae and discs) and "nonspecific" (pain, sprains, and strains). The history of compensated work absence for low back pain in the following 24 months was obtained. RESULTS: A specific diagnosis was found in 8.9% (165) of the workers, accounting for 31.0% of the patients who accumulated 6 months or more of absence in 2 years. Increasing age and daily amount of compensation also were associated with an increased risk of chronicity. CONCLUSIONS: The physician's initial diagnosis was highly associated with the risk of chronicity. The explanation for this result is complex, involving the nature of the underlying lesion as well as the impact of the diagnosis "label" on the worker and on the physician-patient relationship.

A logistic regression analysis of multiple noninvasive tests for the prediction of the presence and extent of coronary artery disease in men.

The incremental diagnostic yield of clinical data, exercise ECG, stress thallium scintigraphy, and cardiac fluoroscopy to predict coronary and multivessel disease was assessed in 171 symptomatic men by means of multiple logistic regression analyses. When clinical variables alone were analyzed, chest pain type and age were predictive of coronary disease, whereas chest pain type, age, a family history of premature coronary disease before age 55 years, and abnormal ST-T wave changes on the rest ECG were predictive of multivessel disease. The percentage of patients correctly classified by cardiac fluoroscopy (presence or absence of coronary artery calcification), exercise ECG, and thallium scintigraphy was 9%, 25%, and 50%, respectively, greater than for clinical variables, when the presence or absence of coronary disease was the outcome, and 13%, 25%, and 29%, respectively, when multivessel disease was studied; 5% of patients were misclassified. When the 37 clinical and noninvasive test variables were analyzed jointly, the most significant variable predictive of coronary disease was an abnormal thallium scan and for multivessel disease, the amount of exercise performed. The data from this study provide a quantitative model and confirm previous reports that optimal diagnostic efficacy is obtained when noninvasive tests are ordered sequentially. In symptomatic men, cardiac fluoroscopy is a relatively ineffective test when compared to exercise ECG and thallium scintigraphy.

Noninvasive diagnostic test choices for the evaluation of coronary artery disease in women: a multivariate comparison of cardiac fluoroscopy, exercise electrocardiography and exercise thallium myocardial perfusion scintigraphy.

Several diagnostic noninvasive tests to detect coronary and multivessel coronary disease are available for women. However, all are imperfect and it is not yet clear whether one particular test provides substantially more information than others. The aim of this study was to evaluate clinical findings, exercise electrocardiography, exercise thallium myocardial scintigraphy and cardiac fluoroscopy in 92 symptomatic women without previous infarction and determine which tests were most useful in determining the presence of coronary disease and its severity. Univariate analysis revealed two clinical, eight exercise electrocardiographic, seven myocardial scintigraphic and seven fluoroscopic variables predictive of coronary or multivessel disease with 70% or greater stenosis. The multivariate discriminant function analysis selected a reversible thallium defect, coronary calcification and character of chest pain syndrome (p less than 0.05) as the variables most predictive of presence or absence of coronary disease. The ranked order of variables most predictive of multivessel disease were cardiac fluoroscopy score, thallium score and extent of ST segment depression in 14 electrocardiographic leads. Each provided statistically significant information to the model. The estimate of predictive accuracy was 89% for coronary disease and 97% for multivessel coronary disease. The results suggest that cardiac fluoroscopy or thallium scintigraphy provide significantly more diagnostic information than exercise electrocardiography in women over a wide range of clinical patient subsets.

Clinical and angiographic factors associated with progression of coronary artery disease.

To characterize the clinical and angiographic factors associated with progression of coronary atherosclerosis, 313 consecutive medically treated patients who had had two coronary arteriograms 3 to 119 months (mean 39 +/- 25) apart were studied. One hundred eighty-one patients underwent recatheterization for stable angina, 52 for unstable angina and 80 for various other reasons. In addition to the conventional angiographic features present at the first angiographic study (number of diseased vessels 1.5 +/- 0.8, ejection fraction 59 +/- 11%), an extent score was defined based on the number of coronary segments with 5 to 75% narrowings from a 15 segment coding system. Multivariate logistic regression identified four independent predictors of progression of coronary artery disease: the interval between studies (p less than 0.0001), unstable angina (p less than 0.0001), a high extent score (p = 0.0001) and young age (p = 0.0026). In a subset of 74 patients aged 50 years or younger with, at the time of the first evaluation, an extent score of 4 or more, the probability of progression between 2 and 4 years and after 4 years was, respectively, 80 and 90% compared with 50% for the other patients. Risk stratification for progression of coronary artery disease can thus be obtained.