In Canada The Cost of Treating Osteoarthritis Expected to Quadruple
Osteoarthritis, or OA as it is commonly called, is the most common joint disease affecting middle-age and older people. It is characterized by progressive damage to the joint cartilage-the cushioning material at the end of long bones. It can cause changes in the structures around the joint including fluid accumulation, bony overgrowth, and weakness of muscles and tendons, all of which may limit movement and cause pain and swelling.
To estimate the number of people in Canada who would be diagnosed with osteoarthritis by the year 2031, researchers from the Arthritis Research Centre of Canada developed a population-based microsimulation - a computer model that creates life histories of all people in the Canadian population in terms of OA risk factors and its burden - called Population Health Model-Osteoarthritis (POHEM - OA). The study used data from the 2001 Canadian Community Health Survey and was conducted to assess treatment and future health care costs for the years 2010 to 2031.
"This is the first time an individual-level simulation model was used in conjunction with a cost-of-illness study to project the direct cost burden of osteoarthritis in the next 20 years," says Behnam Sharif, MSc, lead investigator in the study and PhD Candidate at the School of Population and Public Health, University of British Columbia in Vancouver, Canada.
Researchers reviewed health care records between 1986 and 2003 that included physician visits, surgical procedures, medication, and all hospital admissions covered by the Medical Services Plan (a government-assisted health insurance plan for British Columbia residents). Surgical procedures related to OA were estimated based on expenses from the St. Paul''s Hospital in Vancouver. The researchers then used Canadian Joint Registry data collected between 1997 and 2007 to estimate the total number of hip and knee replacements. Average drug costs (both over-the-counter and prescription drugs) were then estimated by evaluating data for the four main types of drugs prescribed to treat OA (acetaminophen, nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 inhibitors and opioids).
Each patient was assigned a cost variable, which reflects costs of care, based on sex, age, disease activity, orthopedic surgeon assessment, primary joint replacement surgery and any additional surgeries. The researchers entered all of the collected data into the POHEM model and divided medical expenses into two categories - ongoing costs and event-based costs. Ongoing costs were calculated based on the number of years living with the disease. Event-based costs were considered expenses for hip and knee surgeries.
Based on the results of the modeling, total health care costs of treating Canadians with OA were estimated to rise from $1.8 billion dollars in 2010 to $8.1 billion dollars in 2031. The rise in cost was directly associated with an increase in the number of people living with the disease. The model predicted an increase in the number of people with OA from three million (14 percent) in 2010 to 5.8 million (18 percent) in 2031. Other factors that contributed to rising medical costs to treat patients with OA are growing demand for total knee and hip replacements and the aging of the OA population.
"Our research shows that OA will continue to be a major concern for health policy makers in the next two decades, as the baby boomers enter the last decades of their lives. This research also underscores the importance of disease prevention to reduce the burden of OA," says Mr. Sharif.
This study was funded by a grant from the Canadian Institutes of Health Research. Mr. Sharif is supported by a doctoral scholarship from the Canadian Arthritis Network.