Little is known about the association between health-related quality of life (HRQOL) and osteoporosis in the absence of fracture, and how HRQOL may change over time. This study provides evidence of substantially reduced HRQOL in women and men with self-reported and/or BMD-confirmed osteoporosis, even in the absence of fragility fracture.
Fragility fractures have a detrimental effect on the health-related quality of life (HRQOL) of those with osteoporosis. Less is known about the association between HRQOL and osteoporosis in the absence of fracture. Canadian Multicentre Osteoporosis Study participants completed the SF-36, a detailed health questionnaire and measures of bone mineral density (BMD) at baseline and follow-up. We report the results of participants ≥ 50 years with 10-year follow-up. Self-reported osteoporosis at baseline and BMD-based osteoporosis at follow-up were ascertained. Multivariable linear regression models were developed for baseline SF-36 domains, component summaries, and change over time, adjusting for relevant baseline information. Baseline data were available for 5266 women and 2112 men. Women in the osteoporosis group had substantially lower SF-36 baseline scores, particularly in the physically oriented domains, than those without osteoporosis. A similar but attenuated pattern was evident for the men. After 10-year follow-up (2797 women and 1023 men), most domain scores dropped for women and men regardless of osteoporosis status, with the exception of mentally-oriented ones. In general, a fragility fracture was associated with lower SF-36 scores and larger declines over time. This study provides evidence of substantially reduced HRQOL in women and men with self-reported and/or BMD-confirmed osteoporosis, even in the absence of fragility fracture. HRQOL should be thoroughly investigated even prior to fracture, to develop appropriate interventions for all stages of the disease.
To prospectively assess changes in health-related quality of life (HRQOL) over 10 years, by age and sex, and to compare measured within-person change to estimates of change based on cross-sectional data. Participants in the Canadian Multicentre Osteoporosis Study completed the 36-item short form (SF-36) in 1995/1997 and 2005/2007. Mean within-person changes for domain and summary components were calculated for men and women separately, stratified by 10-year age groups. Projected changes based on published ageand sex-stratified cross-sectional data were also calculated. Mean differences between the two methods were then estimated, along with the 95 % credible intervals of the differences. Data were available for 5,569/9,423 (59.1 %) of the original cohort. Prospectively collected 10-year changes suggested that the four physically oriented domains declined in all but the youngest group of men and women, with declines in the elderly men exceeding 25 points. The four mentally oriented domains tended to improve over time, only showing substantial declines in vitality and role emotional in older women, and all four domains in older men. Cross-sectional estimates identified a similar pattern of change but with a smaller magnitude, particularly in men. Correspondence between the two methods was generally high. Changes in HRQOL may be minimal over much of the life span, but physically oriented HRQOL can decline substantially after middle age. Although clinically relevant declines were more evident in prospectively collected data, differences in 10-year age increments of cross-sectional data may be a reasonable proxy for longitudinal changes, at least in those under 65 years of age. Results provide additional insight into the natural progression of HRQOL in the general population.
Berger C et al., 2012·J Bone Miner Res·
Open Access
Vitamin D is essential for facilitating calcium absorption and preventing increases in parathyroid hormone (PTH), which can augment bone resorption. Our objectives were to examine serum levels of 25-hydroxyvitamin D [25(OH)D] and PTH, and factors related to longitudinal change in a population-based cohort. This is the first longitudinal population-based study looking at PTH and 25(OH)D levels. We analyzed 3896 blood samples from 1896 women and 829 men in the Canadian Multicentre Osteoporosis Study over a 10-year period starting in 1995 to 1997. We fit hierarchical models with all available data and adjusted for season. Over 10 years, vitamin D supplement intake increased by 317 (95% confidence interval [CI] 277 to 359) IU/day in women and by 193 (135 to 252) IU/day in men. Serum 25(OH)D (without adjustment) increased by 9.3 (7.3 to 11.4) nmol/L in women and by 3.5 (0.6 to 6.4) nmol/L in men but increased by 4.7 (2.4 to 7.0) nmol/L in women and by 2.7 (-0.6 to 6.2) nmol/L in men after adjustment for vitamin D supplements. The percentage of participants with 25(OH)D levels <50 nmol/L was 29.7% (26.2 to 33.2) at baseline and 19.8% (18.0 to 21.6) at year 10 follow-up. PTH decreased over 10 years by 7.9 (5.4 to 11.3) pg/mL in women and by 4.6 (0.2 to 9.0) pg/mL in men. Higher 25(OH)D levels were associated with summer, younger age, lower body mass index (BMI), regular physical activity, sun exposure, and higher total calcium intake. Lower PTH levels were associated with younger age and higher 25(OH)D levels in both women and men and with lower BMI and participation in regular physical activity in women only. We have observed concurrent increasing 25(OH)D levels and decreasing PTH levels over 10 years. Secular increases in supplemental vitamin D intake influenced both changes in serum 25(OH)D and PTH levels.
Berger C et al., 2010·J Bone Miner Res·
Open Access
We estimated peak bone mass (PBM) in 615 women and 527 men aged 16 to 40 years using longitudinal data from the Canadian Multicentre Osteoporosis Study (CaMos). Individual rates of change were averaged to find the mean rate of change for each baseline age. The age range for PBM was defined as the period during which bone mineral density (BMD) was stable. PBM was estimated via hierarchical models, weighted according to 2006 Canadian Census data. Lumbar spine PBM (1.046 ± 0.123 g/cm(2)) occurred at ages 33 to 40 years in women and at 19 to 33 years in men (1.066 ± 0.129 g/cm(2)). Total hip PBM (0.981 ± 0.122 g/cm(2)) occurred at ages 16 to 19 years in women and 19 to 21 years in men (1.093 ± 0.169 g/cm(2)). Analysis of Canadian geographic variation revealed that the levels of PBM and of mean BMD in those over age 65 sometimes were discordant, suggesting that PBM and subsequent rates of bone loss may be subject to different genetic and/or environmental influences. Based on our longitudinally estimated PBM values, the estimated Canadian prevalences of osteoporosis (T-score < -2.5) were 12.0% (L(1)-L(4)) and 9.1% (total hip) in women aged 50 years and older and 2.9% (L(1)-L(4)) and 0.9% (total hip) in men aged 50 years and older. These were higher than prevalences using cross-sectional PBM data. In summary, we found that the age at which PBM is achieved varies by sex and skeletal site, and different reference values for PBM lead to different estimates of the prevalence of osteoporosis. Furthermore, lack of concordance of PBM and BMD over age 65 suggests different determinants of PBM and subsequent bone loss.
Measurement and Statistics · Instrument Development and Validation
Hopman WM et al., 2009·Can J Public Health·
Open Access
Normative data for the SF-36 measure of health-related quality of life (HRQOL) exist for those over 25 years of age, based on data from the population-based Canadian Multicentre Osteoporosis Study (CaMos). CaMos recently recruited a sample of young Canadians aged between 16 and 24 years. The purpose of this study was to develop normative SF-36 data for this age group. After direct standardization to the Canadian population, means, standard deviations (SD), 95% confidence intervals and percentage at floor and ceiling were produced for the eight domain and two summary scores of the SF-36. Domains are scored from 0 (poor) to 100 (excellent). Summary scores are standardized to a mean of 50, with scores over 50 representing better than average and below 50 poorer than average function. Separate analyses were completed for men and women, and for those 16-19 years and 20-24 years. The 1,001 community-based participants consisted of 474 men and 527 women from nine CaMos centres across Canada. Mean Physical Component Summary scores were 53.9 (SD = 6.9) and 53.3 (SD = 5.7) for young men and women, respectively. The equivalent Mental Component Summary scores were 49.3 (SD = 9.7) and 48.8 (SD = 8.9). In general, men scored somewhat higher than women, and younger (16-19 years) women scored higher than older (20-24 years) women, although the differences were small. HRQOL is good in this cohort of young Canadians. Both men and women scored somewhat better on physically than mentally oriented domains. In general, Canadian scores were similar to those of the US, while a comparable Swedish sample scored higher than both countries on most domains. Results underscore the importance of taking country, age and gender into consideration when using normative data. Objectifs: Des données normatives sur la qualité de vie liée à la santé (QVLS) dans le questionnaire sur l’état de santé SF-36 existent déjà pour les personnes de plus de 25 ans grâce aux données représentatives de l’Étude canadienne multicentrique sur l’ostéoporose (CaMos). La CaMos a recruté récemment un échantillon de jeunes Canadiens âgés de 16 à 24 ans. Le but de notre étude était d’élaborer des données normatives SF-36 pour ce groupe d’âge. MÉTHODE: Après avoir effectué une standardisation directe à partir de la population canadienne, nous avons calculé les moyennes, les écarts-types (ET), les intervalles de confiance de 95% et le pourcentage minimum et maximum pour les huit domaines et les deux notes globales du SF-36. Les domaines sont notés de 0 (mauvais) à 100 (excellent). Les notes globales sont standardisées selon une moyenne de 50, les notes de plus de 50 indiquant des fonctions supérieures à la moyenne, et les notes de moins de 50, des fonctions inférieures à la moyenne. Nous avons analysé séparément les hommes des femmes, et le groupe des 16 à 19 ans de celui des 20 à 24 ans. RÉSULTATS: Les 1 001 participants sélectionnés dans la communauté comprenaient 474 hommes et 527 femmes des neuf centres CaMos du Canada. Les notes globales moyennes pour la composante santé physique étaient de 53,9 (ET=6,9) et de 53,3 (ET=5,7) pour les jeunes hommes et les jeunes femmes, respectivement. Les notes équivalentes pour la composante santé mentale étaient de 49,3 (ET=9,7) et de 48,8 (ET=8,9). En général, les hommes ont obtenu des notes un peu meilleures que celles des femmes, et les femmes plus jeunes (16 à 19 ans), de meilleures notes que leurs aînées (20 à 24 ans), mais ces différences étaient faibles. La QVLS est bonne dans cette cohorte de jeunes Canadiens. Tant les hommes que les femmes ont obtenu des notes un peu meilleures pour la santé physique que pour la santé mentale. En général, les notes canadiennes étaient semblables à celles des États-Unis, mais un échantillon suédois comparable a obtenu des notes plus élevées que ces deux pays dans la plupart des domaines. Ces résultats soulignent l’importance de tenir compte du pays, de l’âge et du sexe lorsqu’on utilise des données normatives.
Berger C et al., 2008·J Bone Miner Res·
Open Access
Our objective was to estimate the relationship between longitudinal change in BMD and fragility fractures. We studied 3635 women and 1417 men 50-85 yr of age in the Canadian Multicentre Osteoporosis Study who had at least two BMD measurements (lumbar spine, femoral neck, total hip, and trochanter) within the first 5 yr of the study and fragility fractures (any, main, forearm/wrist, ribs, hip) within the first 7 yr. Multiple logistic regression was used to model the relationship between baseline BMD, BMD change, and fragility fractures. We found that, among nonusers of antiresorptives, independent of baseline BMD, a decrease of 0.01 g/cm(2)/yr in total hip BMD was associated with an increased risk of fragility fracture with ORs of 1.15 (95% CI: 1.01; 1.32) in women and 1.34 (95% CI: 1.02; 1.78) in men. The risk of fragility fractures in subgroups such as fast losers and those with osteopenia was better estimated by models that included BMD change than by models that included baseline BMD but excluded BMD change. Although the association between baseline BMD and fragility fractures was similar in users and nonusers of antiresorptives, the association was stronger in nonusers compared with users. These results show that BMD change in both men and women is an independent risk factor for fragility fractures and also predicts fracture risk in those with osteopenia. The results suggest that BMD change should be included with other variables in a comprehensive fracture prediction model to capture its contribution to osteoporotic fracture risk.
Measurement of bone mineral density is the most common method of diagnosing and assessing osteoporosis. We sought to estimate the average rate of change in bone mineral density as a function of age among Canadians aged 25-85, stratified by sex and use of antiresorptive agents. We examined a longitudinal cohort of 9423 participants. We measured the bone mineral density in the lumbar spine, total hip and femoral neck at baseline in 1995-1997, and at 3-year (participants aged 40-60 years only) and 5-year follow-up visits. We used the measurements to compute individual rates of change. Bone loss in all 3 skeletal sites began among women at age 40-44. Bone loss was particularly rapid in the total hip and was greatest among women aged 50-54 who were transitioning from premenopause to postmenopause, with a change from baseline of -6.8% (95% confidence interval [CI] -7.5% to -4.9%) over 5 years. The rate of decline, particularly in the total hip, increased again among women older than 70 years. Bone loss in all 3 skeletal sites began at an earlier age (25-39) among men than among women. The rate of decline of bone density in the total hip was nearly constant among men 35 and older and then increased among men older than 65. Use of antiresorptive agents was associated with attenuated bone loss in both sexes among participants aged 50-79. Interpretation: The period of accelerated loss of bone mineral density in the hip bones occurring among women and men older than 65 may be an important contributor to the increased incidence of hip fracture among patients in that age group. The extent of bone loss that we observed in both sexes indicates that, in the absence of additional risk factors or therapy, repeat testing of bone mineral density to diagnose osteoporosis could be delayed to every 5 years.
Deviation from normal weight is associated with health risks, but less is known about the association between weight and health-related quality of life (HRQOL). We investigated this in the context of a population-based study, using a standard five-category weight classification system based on body mass index (BMI). The Canadian Multicentre Osteoporosis Study is a randomly selected sample of men and women over 25 years of age from nine centres across Canada. Data were obtained by interview, and height and weight were measured and used to calculate BMI. HRQOL was measured using the SF-36. Multivariable linear regression was used to identify the association between BMI category and SF-36 scores after controlling for potential confounders. Complete data were available for 6,302 women and 2,792 men. Mean BMI for every age and gender group exceeded healthy weight guidelines. For women, being underweight, overweight or obese was associated with poorer HRQOL in most SF-36 outcomes while for men, this was associated with poorer HRQOL in some domains and with higher HRQOL in others. A significant proportion of the population may be putting their health at risk due to excess weight, which may have a substantial negative effect on HRQOL, particularly in women. This underscores the need for continued public health efforts aimed at combating overweight and obesity.
Hopman WM et al., 2007·BMC Public Health·
Open Access
The initiation of the Canadian Multicentre Osteoporosis Study in 1996, and subsequent follow-up of the cohort 5 years later, provided longitudinal body mass index (BMI) data for a random sample of Canadians. Height and weight were measured at baseline and 5 years and used to calculate BMI and assign one of six weight categories. Multiple imputation was used to adjust for missing weight at year 5. Data were stratified by age and gender. The proportion of participants moving between categories was generated, and multivariable linear regression was used to identify factors associated with weight change. Baseline data were available for 8548 participants, year 5 data for 6721, and year 5 weight was imputed for 1827 (17.6%). Mean BMI for every age and gender group exceeded healthy weight guidelines. Most remained within their BMI classification over 5 years, but when change occurred, BMI category was more likely to increase than decrease. Several sociodemographic, lifestyle and clinical characteristics were associated with change. Mean baseline BMI tended to be higher than recommended. Moreover, on average, men under age 45 and women under age 55 were gaining approximately 0.45 kilograms (one pound) per year, which leveled off with increased age and reversed in the oldest age groups. These findings underscore the need for public health efforts aimed at combating obesity.
The impact of clinical risk factor-based absolute risk methods on the prevalence of high risk for osteoporotic fracture is unknown. We applied absolute risk methods to 6646 subjects and found that the prevalence of elderly women deemed to be at high risk increased substantially, whereas the overall prevalence was highly dependent on the threshold used to designate high risk.
Many groups have advocated using absolute risk methods that incorporate clinical risk factors to target patients for osteoporosis therapy. We examined how the application of such absolute risk classification systems influences the prevalence of those considered to be at high risk for osteoporotic fracture and compared these systems to one based solely on BMD. Using 6646 subjects from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective, randomly selected, population-based cohort, we assessed three different systems for determining prevalence of high risk for osteoporotic fracture: a BMD-based system; a simplified risk factor system incorporating age, sex, BMD, and two clinical risk factors; and a comprehensive system, incorporating age, sex, BMD, and seven clinical risk factors. The 10-year absolute risks of incident fragility fracture were compared across systems using three different high-risk thresholds. The prevalence of a T score < or = -2.5 was 18.8% (95% CI: 17.7-19.9%) in women and 3.9% (95% CI: 3.0-4.7%) in men. Using a 15% 10-year risk of fracture threshold, the prevalence of women at high risk increased to 46.9% (95% CI: 45.4-48.4) and 42.5% (95% CI: 41.1-43.9) when the comprehensive and simplified risk factor classification systems were used, respectively. Using a 25% 10-year absolute risk threshold, the prevalence of high risk was similar to that of the BMD-based system, whereas the 20% threshold gave intermediate rates. All thresholds analyzed resulted in an increased prevalence of older women at high risk for fracture, whereas only the 15% 10-year risk of fracture threshold resulted in an increase in the prevalence of men at high risk. The application of risk factor-based systems results in an increased prevalence of older women at high risk. The prevalence of individuals at high risk may increase with changes to the methods used to determine those who are eligible for therapy. These data have important implications for the pattern of care and costs of treating osteoporotic fractures.
Depression and osteoporotic fractures are common ailments among elderly persons. Selective serotonin reuptake inhibitors (SSRIs) are frequently used in the treatment of depression in this population, and the association between daily SSRI use and fragility fractures is unclear. Our objective was to examine the effect of daily SSRI use on the risk of incident clinical fragility fracture. A population-based, randomly selected, prospective cohort study of 5008 community-dwelling adults 50 years and older, followed up over 5 years for incident fractures. Clinical fragility fractures were classified as minimal trauma fractures that were clinically reported and radiographically confirmed. The risk of fragility fracture associated with daily SSRI use was determined while controlling for relevant covariates. Daily SSRI use was reported by 137 subjects. After adjustment for many potential covariates, daily SSRI use was associated with substantially increased risk of incident clinical fragility fracture (hazard rate, 2.1; 95% confidence interval, 1.3-3.4). Daily SSRI use was also associated with increased odds of falling (odds ratio, 2.2; 95% confidence interval, 1.4-3.5), lower bone mineral density at the hip, and a trend toward lower bone mineral density at the spine. These effects were dose dependent and were similar for those who reported taking SSRIs at baseline and at 5 years' follow-up. Daily SSRI use in adults 50 years and older remained associated with a 2-fold increased risk of clinical fragility fracture after adjustment for potential covariates. Depression and fragility fractures are common in this age group, and the elevated risk attributed to daily SSRI use may have important public health consequences.
The use of cyclooxygenase-2 (COX-2) inhibitors has been demonstrated to not only impair load-induced bone formation but also prevent menopause-associated bone loss. We hypothesized that COX-2 inhibitor use would be associated with increased bone mineral density (BMD) in postmenopausal women not using estrogen therapy and, conversely, with decreased BMD in men. The Canadian Multicentre Osteoporosis Study is a longitudinal, randomly selected, population-based community cohort. We present data from men (n=2,004) and postmenopausal women age 65 and older (n=2,776) who underwent a BMD measurement and structured interview in the 5th year of the study. The outcome measure was percent difference in BMD (g/cm(2)). Daily COX-2 inhibitor use was reported by 394 subjects. In men, daily use of COX-2 inhibitors was associated with a lower BMD at all hip sites, with a percent difference of -3.1% [95% confidence interval (CI), -6.0, -0.3] between users and nonusers at total hip. In postmenopausal women not using estrogen replacement therapy, daily COX-2 inhibitor use was associated with higher BMD at most sites [percent difference at total hip: +3.0% (95% CI, 0.3, 5.8)]. These effects appeared to be dose-dependent. COX-2 inhibitor use was associated with a lower BMD in men and, on the other hand, with a higher BMD in postmenopausal women not using estrogen replacement therapy. Men who have used COX-2 inhibitors may wish to seek BMD measurement to assess their fracture risk. However, COX-2 inhibitors may have utility in postmenopausal women if bone-selective analogs can be developed.
Limited information exists regarding the natural progression of health-related quality of life (HRQOL) in the general population, as most research has been cross-sectional or has followed populations with specific medical conditions. Such norms are important to establish, because the effect of any intervention may be confounded by changes due to the natural progression of HRQOL over time. Participants were randomly selected from 9 Canadian cities and surrounding rural areas. Changes in the eight domains and 2 summary component scores of the Medical Outcomes Study 36-item short form (SF-36) were examined over a 5 year period (1996/1997-2001/2002). Mean changes were calculated for men and women within 10 year age categories. Multiple imputation was used to adjust for potential selection bias due to missing data. The baseline sample included 6539 women and 2884 men. Loss to follow-up was 17% for women and 23% for men. Mean changes tended to be small, but there was an overall trend towards decreasing HRQOL over time. Changes were more pronounced in the older age groups and in the physically oriented domains. Younger age groups tended towards small mean improvements, particularly in the mentally oriented domains. Large standard errors suggest that on an individual level, large improvements in some participants are balanced by large declines in others. In general, the HRQOL of Canadians appears relatively stable over a 5 year period. However, care should be taken when assessing HRQOL longitudinally in certain age or gender groups, as changes associated with an intervention can potentially be confounded by the natural progression of HRQOL.
Utilizing data from the Canadian Multicentre Osteoporosis Study (CaMos), we examined the association between potential risk factors and incident vertebral and nonvertebral fractures. A total of 5,143 postmenopausal women were enrolled. Information collected during the study included data from the CaMos baseline and annually mailed fracture questionnaires, the Short Form 36 (SF-36), the Health Utilities Index, and physical measurements. Participants were followed for 3 years. Postmenopausal women were classified into four groups according to their incident fracture status since baseline: those without a new fracture; those with a new clinically recognized vertebral fracture; those with an incident nonvertebral fracture at the wrist, hip, humerus, pelvis, or ribs (main nonvertebral fracture group); and those with any new nonvertebral fracture (any-nonvertebral-fracture group). We performed multivariate Cox proportional hazard analysis using all possible risk factors to determine the association between risk factors and the time to the first minimal trauma fracture. Best predictive models were also determined using variables that were included in the full models. The Bayesian information criterion was used for model selection. For all analyses, relative risks and associated 95% confidence intervals were calculated. During the follow-up period, 34, 163, and 280 women developed a vertebral, a main nonvertebral, or any nonvertebral fracture, respectively. The best predictive models indicated that a five point lower quality of life as measured by the SF-36 physical component summary score was associated with relative risks of 1.21 (95% CI, 1.02 to 1.44), 1.17 (95% CI, 1.07 to 1.28), and 1.19 (95% CI, 1.11 to 1.27) for incident vertebral, main nonvertebral, and all nonvertebral fractures, respectively. In addition, for a one standard deviation (SD=0.12) lower femoral neck BMD, the relative risks for incident vertebral, main nonvertebral, and any nonvertebral fractures increased by 2.73 (95% CI, 1.74 to 4.28), 1.39 (95% CI, 1.06 to 1.82), and 1.34 (95% CI, 1.09 to 1.65), respectively. Furthermore, various anthropometric measures, disease conditions, and medications are associated with a new fracture. Identifying postmenopausal women at risk is important given that fracture prevention therapies are now available.
Measurement and Statistics · Instrument Development and Validation
The SF-36 is widely used to assess health-related quality of life (HRQOL), but with few longitudinal studies in healthy populations, it is difficult to quantify its natural history. This is important because any measure of change following an intervention may be confounded by natural changes in HRQOL. This paper assesses mean changes in SF-36 scores over a 3-year period in men and women between the ages of 40 and 59 years at baseline. Subjects were randomly selected from nine Canadian cities. Mean SF-36 changes over a 3-year period (1996/1997-1999/2000) were calculated for each gender within 5-year age categories. Multiple imputation was used to correct for potential bias due to missing data. The baseline cohort included 1,974 women and 975 men between 40 and 59 years. Mean changes in HRQOL tended to be small. Women demonstrated small average declines in 22 of the 32 age and domain groupings (4 age groups, 8 SF-36 domains) while men showed declines in 14/32. Most participants stayed within 10 points of their original baseline score. Interpretation: Mean SF-36 scores change only slightly over three years in middle-aged Canadians, although there is much individual variation. It may be necessary to adjust for the natural evolution of SF-36 scores when interpreting results from longitudinal studies. Contexte: Le SF-36 est un court questionnaire très utilisé pour évaluer la qualité de vie liée à la santé (HRQOL). Toutefois, vu le petit nombre d’études longitudinales menées auprès de populations en bonne santé, il est difficile d’évaluer l’histoire naturelle du SF-36, ce qui est important parce que tout changement noté résultant d’une intervention peut être confondu avec des changements normaux de la qualité de vie liée à la santé. Cet article évalue les changements moyens dans les scores des SF-36 sur une période de trois ans chez les hommes et les femmes qui étaient âgés de 40 à 59 ans lors de leur visite initiale. Méthode: Les sujets ont été choisis au hasard dans neuf villes canadiennes. Les changements moyens dans les résultats du SF-36 sur une période de trois ans (1996–1997 à 1999–2000) ont été calculés par sexe et par groupe d’âge de cinq ans. L’imputation multiple a été utilisée pour corriger tout biais résultant d’informations manquantes. Résultats: La cohorte initiale comportait 1 974 femmes et 975 hommes âgés de 40 à 59 ans. Les changements moyens étaient plutôt légers. Chez les femmes, 22 des 32 groupes d’âge et sous-échelles (quatre groupes d’âge, huit sous-échelles SF-36) présentaient de légères diminutions moyennes, alors que chez les hommes, ce nombre était de 14 groupes sur 32. Le score de la plupart des participants est demeuré en deçà de 10 points du score initial lors de l’entrée dans l’étude. Interprétation: Les scores moyens du SF-36 ne changent que légèrement sur une période de trois ans dans la population canadienne d’âge moyen. Toutefois, il pourrait s’avérer nécessaire de tenir compte de l’évolution naturelle des scores du SF-36 lors de l’interprétation des résultats d’études longitudinales.
Osteoporotic fractures can be a major cause of morbidity. It is important to determine the impact of fractures on health-related quality of life (HRQL). A total of 3,394 women and 1,122 men 50 years of age and older, who were recruited for the Canadian Multicentre Osteoporosis Study (CaMos), participated in this cross-sectional study. Minimal trauma fractures of the hip, pelvis, spine, lower body (included upper and lower leg, knee, ankle, and foot), upper body (included arm, elbow, sternum, shoulder, and clavicle), wrist and hand (included forearm, hand, and finger), and ribs were studied. Participants with subclinical vertebral deformities were also examined. The Health Utilities Index Mark II and III Systems were used to assess HRQL. Past osteoporotic fractures varied in prevalence from 1.2% (pelvis) to 27.8% (lower body) in women and 0.3% (pelvis) to 29.3% (wrist) in men. Multivariate linear regression analyses [parameter estimates and corresponding 95% confidence intervals (CI)] indicated that minimal trauma fractures were negatively associated with HRQL and that this relationship depends on fracture type and gender. The multi-attribute scores for the Mark II system were negatively related to hip (-0.05; 95% CI: -0.09, -0.01), lower body (-0.02; 95% CI: -0.03, -0.000), and subclinical vertebral fractures (-0.02; 95% CI: -0.03, -0.00) for women. The multi-attribute scores for the Mark III system were negatively related to hip (-0.09; 95% CI: -0.14, -0.03) and rib fractures (-0.06; 95% CI: -0.11, -0.00) for women, and rib fractures (-0.06; 95% CI: -0.12, -0.00) for men. In conclusion, this study demonstrates a negative association between osteoporotic fractures and quality of life in both women and men.
This cross-sectional cohort study of 5566 women and 2187 men 50 years of age and older in the population-based Canadian Multicentre Osteoporosis Study was conducted to determine whether reported past diseases are associated with bone mineral density or prevalent vertebral deformities. We examined 12 self-reported disease conditions including diabetes mellitus (types 1 or 2), nephrolithiasis, hypertension, heart attack, rheumatoid arthritis, thyroid disease, breast cancer, inflammatory bowel disease, neuromuscular disease, Paget's disease, and chronic obstructive pulmonary disease. Multivariate linear and logistic regression analyses were performed to determine whether there were associations among these disease conditions and bone mineral density of the lumbar spine, femoral neck, and trochanter, as well as prevalent vertebral deformities. Bone mineral density measurements were higher in women and men with type 2 diabetes compared with those without after appropriate adjustments. The differences were most notable at the lumbar spine (+0.053 g/cm2), femoral neck (+0.028 g/cm2), and trochanter (+0.025 g/cm2) in women, and at the femoral neck (+0.025 g/cm2) in men. Hypertension was also associated with higher bone mineral density measurements for both women and men. The differences were most pronounced at the lumbar spine (+0.022 g/cm2) and femoral neck (+0.007 g/cm2) in women and at the lumbar spine (+0.028 g/cm2) in men. Although results were statistically inconclusive, men reporting versus not reporting past nephrolithiasis appeared to have clinically relevant lower bone mineral density values. Bone mineral density differences were -0.022, -0.015, and -0.016 g/cm2 at the lumbar spine, femoral neck, and trochanter, respectively. Disease conditions were not strongly associated with vertebral deformities. In summary, these cross-sectional population-based data show that type 2 diabetes and hypertension are associated with higher bone mineral density in women and men, and nephrolithiasis may be associated with lower bone mineral density in men. The importance of these associations for osteoporosis case finding and management require further and prospective studies.
Hopman WM et al., 2002·Can J Public Health·
Open Access
Canadian normative data for the Medical Outcomes Study 36-item short form (SF-36) have recently been published. However, there is evidence from other countries to suggest that regional variation in health-related quality of life (HRQOL) may exist. We therefore examined the SF-36 data from nine Canadian centres for evidence of systematic differences. Bayesian hierarchical modelling was used to compare the differences in the eight SF-36 domains and the two summary component scores within each of the age and gender strata across the nine sites. Five domains and the two summary component scores showed little clinically important variation. Other than a small number of exceptions, there was little overall evidence of HRQOL differences across most domains and across most sites. Interpretation: Our finding of only a few small differences suggests that there is no need to develop region-specific Canadian normative data for the SF-36 health survey. Contexte: Les données normatives canadiennes s’appliquant à la version abrégée du questionnaire sur l’évolution médicale comportant 36 questions (SF-36) ont été publiées récemment. Toutefois, les données recueillies dans d’autres pays suggèrent qu’il peut exister des variations régionales au niveau de la qualité de vie reliée à l’état de santé (HRQOL). Nous avons donc étudié les données du SF-36 provenant de neuf centres canadiens pour démontrer les différences systématiques. Méthodes: Un modèle hiérarchique bayésien a été utilisé pour comparer les différences entre les résultats des huit domaines du SF-36 et des deux composantes sommaires pour chaque strate d’âge et de sexe, et ce, pour les neuf centres. Résultats: Les résultats de cinq domaines et des deux composantes sommaires démontraient des différences peu significatives cliniquement. Outre de rares exceptions, il y avait peu d’évidence de variations du HRQOL entre la plupart des domaines et des centres. Interprétation: Les résultats obtenus, ne démontrant que de légères différences, suggèrent qu’il n’est pas nécessaire d’établir des données normatives spécifiques aux régions du Canada pour le questionnaire de santé SF-36.
Positive and negative effects on bone mineral density (BMD) have been described as a result of the premenopausal use of oral contraceptives (OCs); increased fracture rates have also been reported. This study assessed the relation between OC use and BMD in a population-based, 9-centre, national sample of women aged 25-45 years. Premenopausal women who had been enrolled in the Canadian Multicentre Osteoporosis Study were classified as having ever been OC users (> or = 3 months) or as having never been OC users (0 to < 3 months). Data were obtained through extensive questionnaires and measuring of participants' weight, height and the BMD of lumbar vertebrae and the proximal femur. Of the sample of 524 women, whose mean age was 36.3 (standard deviation [SD] 5.9) years, 454 had used OCs; their mean age when they started using OCs was 19.8 (SD 3.5) years and the mean duration of use was 6.8 (SD 4.8) years. Women who had ever and those who had never used OCs showed no differences in age, age at menarche, parity, current calcium intake, exercise, body mass index (BMI), education, past irregular cycles or amenorrhea. OC users reported more alcohol and cigarette use and more use of medications to create regular cycles. Mean BMD values (adjusted for age, BMI and height) were 0.02-0.04 g/cm2 (that is, 2.3%-3.7%) lower in OC users, and were significantly lower in the spine and trochanter. The BMD of the spine in OC users was 1.03 (SD 0.12) g/cm2 versus 1.07 (SD 0.12) g/cm2 (95% confidence interval [CI] of difference -0.07 to -0.001) in those who had never used OCs. BMD was neither related to the duration of OC use nor to gynecological age at first use. Current and past users had similar BMD values. Interpretation: National, population-based data show lower BMD values for the trochanter and spine in premenopausal women who have used OCs compared with those who have never used OCs.
Health-related quality of life (HRQL) was examined in relation to prevalent fractures in 4816 community-dwelling Canadian men and women 50 years and older participating in the Canadian Multicentre Osteoporosis Study (CaMos). Fractures were of three categories: clinically recognized main fractures, subclinical vertebral fractures and fractures at other sites. Main fractures were divided and analyzed at the hip, spine, wrist/forearm, pelvis and rib sites. Baseline assessments of anthropometric data, medical history, therapeutic drug use, spinal radiographs and prevalent fractures were obtained from all participants. The SF-36 instrument was used as a tool to measure HRQL. A total of 652 (13.5%) main fractures were reported. Results indicated that hip, spine, wrist/forearm, pelvis and rib fractures had occurred in 78 (1.6%), 40 (0.8%), 390 (8.1%), 19 (0.4%) and 125 (2.6%) individuals, respectively (subjects may have had more than one main fracture). Subjects who had experienced a main prevalent fracture had lower HRQL scores compared with non-fractured participants. The largest differences were observed in the physical functioning (-4.0; 95% confidence intervals (CI): -6.0, -2.0) and role-physical functioning domains (-5.8; 95% CI: -9.5, -2.2). In women, the physical functioning domain was most influenced by hip (-14.9%; 95% CI: -20.9, -9.0) and pelvis (-18.1; 95% CI: -27.6, -8.6) fractures. In men, the role-physical domain was most affected by hip fractures (-35.7; 95% CI: -60.4, -11.1). Subjects who experienced subclinical vertebral fractures had lower HRQL scores than those without prevalent fractures. In conclusion, HRQL was lower in the physical functioning domain in women and the role-physical domain in men who sustained main fractures at the hip. Subclinical vertebral fractures exerted a moderate effect on HRQL.
Identification of women with low bone mineral density (BMD) is an important strategy in reducing the incidence of osteoporotic fractures. However, screening all women is not recommended. To assess the diagnostic properties of 4 decision rules--Simple Calculated Osteoporosis Risk Estimation (SCORE), Osteoporosis Risk Assessment Instrument (ORAI), Age, Body Size, No Estrogen (ABONE), and body weight less than 70 kg (weight criterion)--for selecting women for dual-energy x-ray absorptiometry (DXA) testing and to compare results with recommendations made in the National Osteoporosis Foundation (NOF) practice guidelines. DESIGN AND Analysis of data from the Canadian Multicentre Osteoporosis Study, a population-based community sample, collected from 9 study centers across Canada between February 1996 and September 1997. Postmenopausal women aged 45 years or older (N = 2365) without bone disease who had DXA data for the femoral neck, data to apply selection criteria, and who were not currently taking estrogens or who had been taking hormone replacement therapy for 5 or more years. Sensitivity, specificity, and area under the receiver operating characteristic (AUROC) curve of each of the 4 decision rules and the NOF guidelines for identifying women with a BMD T score of less than -1.0 SD, less than -2.0 SD, and no more than -2.5 SD at the femoral neck, and percentages of women recommended for testing, stratified by BMD level and age. The percent of women with a BMD T score less than -1, less than -2, and no more than -2.5 were 68.3%, 25.4%, and 10.0%, respectively. The AUROC curves were greatest using SCORE and ORAI. The sensitivity for identifying women with a BMD T score of less than -2.0 was 93.7% (95% confidence interval [CI], 91.8%-95.6%) using the NOF guidelines and was 97.5% (95% CI, 96.3%-98.8%), 94.2% (95% CI, 92.3%-96.1%), 79.1% (95% CI, 75.9%-82.3%), and 79.6% (95% CI, 76.4%-82.8%), respectively, using the SCORE, ORAI, ABONE, and weight criterion. However, the NOF guidelines also resulted in 74.4% (95% CI, 71.3%-77.6%) of women with a normal BMD (T score of -1.0 or higher) being tested compared with 69.2% (95% CI, 65.9%-72.5%), 56.3% (95% CI, 52.7%-59.8%), 35.8% (95% CI, 32.4%-39.2%), and 38.1% (95% CI, 34.6%-41.6%), respectively, using the 4 decision rules. Assessments suggest that ABONE and weight criterion are not useful case-finding approaches. The SCORE and ORAI decision rules are better than the NOF guidelines at targeting BMD testing in high-risk patients. The acceptability of these rules in clinical practice merits further investigation given their potential effect on the use of densitometry services.
The Canadian Multicentre Osteoporosis Study (CaMos) is a prospective cohort study which will measure the incidence and prevalence of osteoporosis and fractures, and the effect of putative risk factors, in a random sample of 10,061 women and men aged > or = 25 years recruited in approximately equal numbers in nine centers across Canada. In this paper we report the results of studies to establish peak bone mass (PBM) which would be appropriate reference data for use in Canada. These reference data are used to estimate the prevalence of osteoporosis and osteopenia in Canadian women and men aged > or = 50 years. Participants were recruited via randomly selected household telephone listings. Bone mineral density (BMD) of the lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry using Hologic QDR 1000 or 2000 or Lunar DPX densitometers. BMD results for lumbar spine and femoral neck were converted to a Hologic base. BMD of the lumbar spine in 578 women and 467 men was constant to age 39 years giving a PBM of 1.042 +/- 0.121 g/cm2 for women and 1.058 +/- 0.127 g/cm2 for men. BMD at the femoral neck declined from age 29 years. The mean femoral neck BMD between 25 and 29 years was taken as PBM and was found to be 0.857 +/- 0.125 g/cm2 for women and 0.910 +/- 0.125 g/cm2 for men. Prevalence of osteoporosis, as defined by WHO criteria, in Canadian women aged > or = 50 years was 12.1% at the lumbar spine and 7.9% at the femoral neck with a combined prevalence of 15.8%. In men it was 2.9% at the lumbar spine and 4.8% at the femoral neck with a combined prevalence of 6.6%.
Measurement and Statistics · Instrument Development and Validation
The Medical Outcomes Study 36-item Short Form (SF-36) is a widely used measure of health-related quality of life. Normative data are the key to determining whether a group or an individual scores above or below the average for their country, age or sex. Published norms for the SF-36 exist for other countries but have not been previously published for Canada. The Canadian Multicentre Osteoporosis Study is a prospective cohort study involving 9423 randomly selected Canadian men and women aged 25 years or more living in the community. The sample was drawn within a 50-km radius of 9 Canadian cities, and the information collected included the SF-36 as a measure of health-related quality of life. This provided a unique opportunity to develop ageand sex-adjusted normative data for the Canadian population. Canadian men scored substantially higher than women on all 8 domains and the 2 summary component scales of the SF-36. Canadians scored higher than their US counterparts on all SF-36 domains and both summary component scales and scored higher than their UK counterparts on 4 domains, although many of the differences are not large. Interpretation: The differences in the SF-36 scores between age groups, sexes and countries confirm that these Canadian norms are necessary for comparative purposes. The data will be useful for assessing the health status of the general population and of patient populations, and the effect of interventions on health-related quality of life.
Relatively little is known about the factors in Canada which lead to osteoporosis and its concomitant fractures. The Canadian Multicentre Osteoporosis Study (CaMos) is a prospective cohort study which will estimate the incidence and prevalence of declining bone mass and fractures. The impact of osteoporosis in Canada will be assessed, including regional variation and the effect of various risk factors. The study will provide information for developing prevention programs. The cohort has been drawn from a random population-based sample of non-institutionalized men and women 25 years old or more and living within 50 km. of nine cities in Canada. Through telephone interviews 9,423 participants have been recruited. All answered an extensive questionnaire, and had physical measurements related to bone quality taken. This paper details the CaMos baseline and five-year follow-up protocol.