About the study

Osteoporosis is the most common metabolic bone disease in the elderly affecting an estimated 25% of post-menopausal women in North America, and is a major determinant of fracture occurrence. Patients suffering hip fractures are at high risk for death in the first year following their injury, and vertebral osteoporosis is a cause of substantial pain, loss of functional ability and psychosocial difficulty.However, little is known about the dimensions of osteoporosis in Canada. Recent data from Sweden suggests that each hip fracture represents a total cost of $26 000 US, including:

• $6 000 initial hospital stay
• $12 000 rehabilitation
• $8 000 in aid from the social welfare system

The economic impact in Canada is thought to be similar, and researchers believe current costs will double during the next 30 years unless comprehensive programs for screening, prevention and treatment are started.To develop the programs needed to combat this major public health problem, more information about the population at risk, obtained through primary research, is needed.

Our study population, recruited between 1995 and 1997, includes 9 423 men and women age 25 and older among which 6539 are women and 2884 are men. A youth cohort composed of 474 young men and 527 young women aged 16-24 were recruited between 2004 and 2006. Participants live within 50 kilometers of one of nine CaMos research centres:

1. Vancouver
2. Calgary
3. Saskatoon
4. Toronto
5. Hamilton
6. Kingston
7. Quebec
8. Halifax
9. St. John’s

Recruitment

Initially, a questionnaire was administered and participants underwent  bone mineral density (DXA) of the lumbar spine and hip and ultrasound testing of the shin and wrist.

• Participants aged 50 years and older also had spine X-rays taken at baseline  to assess the prevalence of fractures.
• Blood and urine samples were obtained at 2 centres.

Follow-up

• Participants received a follow up questionnaire annually.
• At the end of the five and ten year periods, all respondents answered an interviewer administered questionnaire and underwent a repeat bone mineral density test (DXA), spine X-rays, and ultrasound.
• Blood and urine samples were collected at the year 5 and year 10 follow-up visit
• At the year 16 follow-up, all respondents aged 60 to 75 answered an interviewer administered questionnaire and underwent a repeat bone mineral density test (DXA) and spine X-rays.
• Blood samples were collected at the year 16 follow-up interview visit.

Analysis of the Data

CaMos will examine:

• the distribution and pattern of change over time of osteoporotic fractures, and of bone characteristics related to osteoporosis, as measured by dual energy X-ray absorptiometry (DXA) and ultrasound.
• the relationship, in Canadian women and men, between  socio-demographic characteristics (e.g. sex, age, race, geographic region) or exposures (e.g. exogenous hormones and medication, diet, physical activity) and these bone characteristics as well as  osteoporotic fractures.
• the impact of osteoporosis and/or fractures on health status
• the economic burden of illness as a result of osteoporotic fractures.

• The 5 year study (Phase 1) was completed in 2002.
  
• The 10 year study (Phase 2) was completed between 2005 and 2008.
  
• The Youth Cohort Study was completed in 2009.
  
• The 16 year study (Phase 2) was completed between 2012 and 2014.