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Keywords:

  • vertebral deformity;
  • impairments;
  • functional limitations;
  • disability;
  • health services use;
  • well-being

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

The objectives of this study were to ascertain the prevalence of the number and severity of vertebral deformities in elderly people and determine the extent to which these are associated with several aspects of functioning. The study was conducted in a subsample of the Longitudinal Aging Study Amsterdam (LASA) consisting of 527 participants (260 men and 267 women), aged 65 years or over. Lateral radiographs of the spine (T4-L5) were made of each participant and a semiquantitative method was used to assess the number and degree of vertebral deformities. The prevalence of having at least one vertebral deformity was 39% in both men and women. Six percent of the men and 5% of the women had at least three vertebral deformities. For severe deformities, the prevalence was 8% in men and 12% in women. The number of vertebral deformities was significantly associated with a height loss of more than 5 cm, difficulties in activities of daily living, poor performance, more than 3 days in bed and more than 3 days with limited activities because of health problems in the past month, and poor self-perceived health. For most of these outcome measures, associations were strongest when three or more deformities were present. The presence of a severe deformity was associated with a height loss of more than 5 cm, poor performance, more than 3 days with limited activities in the past month, and poor self-perceived health. None of the associations between number and severity of vertebral deformities and the level of functioning was modified by sex. We can conclude that vertebral deformities are very common in both older men and older women and that vertebral deformities, even if they are not clinically manifest, have a substantial impact on the level of functioning and well-being of older people.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

VERTEBRAL DEFORMITY is a common consequence of osteoporosis and occurs frequently in older people. The prevalence of vertebral deformities varies between 6% and 25% among people aged 50 years and older depending on the definition used. (1,2)

Only about one out of three vertebral deformities detected by radiographs comes to clinical attention.(3,4) This low rate indicates that vertebral deformities may pass unnoticed without serious symptoms, that patients with complaints do not seek medical care, or that the doctor does not always diagnose vertebral deformities. However, recent population-based studies have shown that clinically undiagnosed vertebral deformities are associated with diminished physical and functional performance, difficulties in performing activities of daily living, and a decline in several aspects of well-being.(4–10) During the last years, there has been growing emphasis on the measurement of functional outcome measures in addition to biomedical measures, such as bone mineral density.(11–14) Insight into the impact of diseases on the person's level of functioning is important for guiding decisions in public health. Because a decline in functioning is strongly associated with increased health care utilization, the information can be used to target services to those most in need and to set priorities in health care. In a clinical setting, measures of functioning are essential as outcome measures in clinical trials to assess the efficacy of different drugs and to set therapeutic goals. (15)

The clinical impact of vertebral deformities may depend on the number or severity of the deformities or on both. A few studies have examined the consequences of severity and number of vertebral deformities on several aspects of everyday functioning.(5,6,16–18) Most of these studies have been conducted only in women and involved either physical or psychosocial functioning.

The current study was conducted as a substudy of the Longitudinal Aging Study Amsterdam (LASA).(19) It includes men and women and a comprehensive range of outcomes has been collected. The main objectives were (1) to determine the prevalence of vertebral deformities according to age and sex and (2) to ascertain to what extent the number and severity of vertebral deformities are associated with functioning in daily life in a group of older men and women.

MATERIALS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

Study sample

Data for this study were collected within the LASA, a 10-year interdisciplinary study on predictors and consequences of changes in autonomy and well-being in the aging population in the Netherlands.(19) For this study, a sample of 3805 older adults (aged 55–85 years), stratified for age, sex, and expected 5 years mortality, was drawn from the population registry of 11 municipalities in areas in the west, northeast, and south of the Netherlands. The sample represents the older Dutch population with respect to geographic region and degree of urbanization. The sampling and data collection procedures have been described in more detail elsewhere.(20)

The subsample of the current study was comprised of participants who participated in the second follow-up of LASA (1995/1996), were born in 1930 or before (aged 65 years and older as of January 1, 1996), and were living in the west of the Netherlands (Amsterdam and its vicinity). Six hundred ninety-eight participants were eligible for inclusion in this study. After an interview at home, the participants were invited to the Academic Hospital of the Vrije Universiteit for additional measurements. Five hundred thirty-five were willing to come to the hospital, yielding a response rate of 77%. Valid spinal radiographs were obtained in 527 of these participants.

All interviews were conducted by specially trained and intensively supervised lay interviewers and were tape-recorded in order to monitor the quality of the data. Informed consent was obtained from all respondents and the study was approved by the Medical Ethics Committee of the Academic Hospital of the Vrije Universiteit and conducted according to the principles of the Helsinki Declaration.

Measurements

Vertebral morphometry

Lateral radiographs of the thoracic and lumbar spine (T4-L5) were obtained in each participant according to the protocol of the European Vertebral Osteoporosis Study.(2) The thoracic film was centered at T7 and the lumbar film at L2. The X-ray tube-to-film distance was 115 cm. The presence and degree of each vertebral deformity was assessed by an experienced clinician using a semiquantitative method.(21) Vertebrae T4-L5 were graded as grade 0 (normal, including minimal deformity with less than 20% reduction in anterior, middle, and/or posterior vertebral height), grade 1 (approximately 20–25% reduction in vertebral height), grade 2 (approximately 25–30% reduction in height), and grade 3 (approximately 30% or greater reduction in height). In the present study, a vertebra scoring of grade 1 or higher was considered a deformed vertebra. Respondents with mild vertebral deformities were defined as having at least one grade 1 deformity without grade 2 or grade 3 deformities. Respondents with moderate vertebral deformities were defined as having at least one grade 2 deformity without grade 3 deformities, while severe deformities were defined as having at least one grade 3 deformity. In a random sample of 50 radiographs, the intraobserver agreement of this semiquantitative method was tested with weighted κ-scores.(22) The κ-score was weighted as described by Altman.(23) Weighted κ-scores for presence of deformity (y/n), severity, and number of deformities were 0.80, 0.75, and 0.63, respectively.

Functional outcome measures

As a surrogate marker for the presence of vertebral deformities, height loss since the age of 40 years was estimated as the difference between the current height measured with a stadiometer and the height at the age of 40 years as reported by the respondent. Consequences of a disease can be classified according to several classifications. According to the model of Verbrugge and Jette,(24) which has been adapted from the well-known model of the World Health Organization,(25) we distinguished five dimensions of functioning: impairments, functional limitations, disability, well-being, and health services use. Because we used different types of outcome measures (continuous, categorical, and dichotomous), we decided to dichotomize all outcome measures to facilitate interpretation and presentation. Cut-off points were chosen at clinically relevant points or, when they did not exist, the risk gradients within deciles and quartiles were examined and the most optimal cut-off was chosen.(26) Because grip strength and peak flow values are generally higher in men than in women, sex-specific cut-off points were taken.

Measures of impairment included maximum peak expiratory flow (PEF) and grip strength. To measure PEF, the participants were asked to expire three times as fast and as hard as possible into a peak flow device. The maximum of three attempts was used in the analyses. Cut-off points were defined as 320 ml/s for men and 250 ml/s for women. Grip strength was determined by using a strain-gauged dynamometer. Respondents were asked to perform two maximum force trials with each hand. The maximum values of the left and right hand were summed up. Cut-off points were 59 kg for men and 34 kg for women.

Functional limitations were assessed with a questionnaire, previously validated in the Netherlands,(27,28) about the degree of difficulty with activities of daily living (ADL) and the ability to perform three physical performance tests.(29) The degree of difficulty with ADL (1, no difficulty; 2, with some difficulty; 3, with much difficulty; 4, only with help; 5, unable to do) was measured by 6 items: climbing stairs, dressing oneself, rising from a chair, cutting toenails, walking outside, and using own or public transportation. Functional limitations were considered to be present when the respondent reported difficulties (score per item, 2–5) with at least three of the six activities. The physical performance tests included time needed to put on a cardigan and take it off (cardigan test), time needed to walk 3 m back and forth along a rope (walking test), and the time to get up from a chair five times with arms folded (chair stands test). For each test, a score of 1–4 points was assigned corresponding to the quartile of the time needed. The more time that was needed, the lower the score. Participants who were not able to perform a test obtained a score of 0 points. For individual tests, respondents were considered physically limited when they had a score of 0–1 points. A total score (range, 0–12 points) was calculated by summation of the scores for the individual tests. Participants were classified as limited if the score was 4 points or less.

Disability was assessed in terms of general functioning(30) and the level of daily physical activities.(31,32) General functioning was assessed by asking the respondents how many days they had stayed in bed because of health problems and the number of days they were limited in performing normal daily activities in the last month. Disability was defined as “more than 3 days in bed because of health problems” or “more than 3 days with limited activities because of health problems.” The level of physical activity was estimated by asking seven yes-or-no questions about participation in the following activities during the past 2 weeks: walking, cycling, gardening, light and heavy household work, participation in one sport, and participation in a second sport. The scores on these seven items were summed up to a physical activity score. This score ranged from 0 (does not participate in any of these activities) to 7 (participates in all seven activities). Respondents were classified as not active when they participated in less than four activities.

Measures of well-being included self-perceived health compared with persons of the same age (very poor or poor vs. excellent, good, or fair),(33) general satisfaction with life (very dissatisfied or dissatisfied vs. not satisfied/not dissatisfied, satisfied, or very satisfied),(33) back pain since the previous examination lasting longer than 1 month, general pain, sleeping problems, and depression. General pain was estimated by using five items of the Nottingham Health Profile (NHP) pain scale.(34) This score ranged from 5 (no pain) to 10 (severe pain). Pain was present when the respondent had a score of 6 or higher. The occurrence of sleep problems (1, almost never; 2, some of the time; 3, often; 4, most of the time) was measured with a three-item questionnaire. The scores of these measures were summed into a total score ranging from 3 to 12. A score of 8 was used as cut-off. Depressive symptoms were assessed by the 20-item Center for Epidemiologic Studies-Depression Scale (CES-D).(35) Participants were classified as depressed if the score was 16 or higher.

Health services use was assessed by self-report. Variables included hospital admission and a visit to a general practitioner, medical specialist, or physical therapist in the past 6 months.

Potentially confounding variables that may be associated with both vertebral deformities and functional outcome measures included sociodemographic characteristics, comorbidity, spinal osteoarthritis, body mass index (BMI), and smoking status (current smoker, yes/no). Sociodemographic characteristics included sex, age, and the level of education, which was quantified as the highest level of education attained categorized into nine levels. Comorbidity was assessed with a detailed questionnaire on self-reported chronic diseases, including chronic obstructive pulmonary disease (COPD), cardiovascular diseases, stroke, diabetes mellitus, malignant neoplasm, osteoarthritis, and rheumatoid arthritis.(36) For this study, we only used the questions on whether respondents reported COPD, diabetes mellitus, osteoarthritis, and rheumatoid arthritis because it is known from literature that these diseases may be related to vertebral deformities. In addition, all radiographs were assessed for spinal osteoarthritis by using the Kellgren scale with a score ranging from 1 (small osteophytes) to 4 (large osteophytes and pronounced disc degeneration).

Data analysis

Means, SDs, and frequencies were used to describe sample characteristics. The crude prevalence of vertebral deformities was calculated for both sexes with respect to number and severity. Logistic regression analysis was used to examine the associations between vertebral deformities and functional outcome measures. Functional outcome measures were the dependent variables, with the number, the severity, or a combination score of number and severity as independent variables. Number of vertebral deformities was entered both as continuous and as categorical variable with four categories: zero, one, two, three, or more deformities. The number of vertebral deformities was then recoded as three dummy variables with the absence of deformities as the reference category. The same was done for severity, for which the presence of a mild, moderate, or severe deformity was compared with the absence of deformities. To obtain a combination score of the number and severity of deformities, the grade of severity of each deformed vertebra was added up so that a continuous score was obtained ranging in this study from 0–11. Results are presented as odds ratios (ORs) with 95% confidence intervals (CIs). All multivariate models included adjustments for potential confounders. For each association, we evaluated which of the potential confounders changed the OR. Those who changed the strength of the association substantially were then included as confounders. In addition, an interaction term was included in all models to examine possible effect modification between sex and vertebral deformities. If the associations were significantly different for men and women, the data are presented for men and women separately. Because variance is lost when continuous measures are dichotomized, we checked the results of the logistic regression models with multiple regression models for the outcome measures PEF, grip strength, functional limitations, physical performance, physical activity, self-perceived health, pain, sleeping problems, life satisfaction, and depression.

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

The sample included 260 (49.3%) men and 267 (50.1%) women. The mean age was 75.2 ± 6.3 years (range, 65.3-88.7 years). Nonresponse was significantly associated with a number of functional outcome variables. The respondents who did not come to the hospital were older, had more height loss, had lower peak flow values, had lower grip strength, had more functional limitations, had lower physical performance, were less physically active, had lower self-perception of health, were less satisfied about their lives, and had higher depression scores. After correcting for age, the outcome measures grip strength, functional limitations, level of physical performance, level of physical activity, self-perceived health, and depression score remained significantly associated with nonresponse. There were no associations between attrition and sex, the number of days in bed in the past month, the number of days with limited activities because of health problems, back pain, pain, and the various measures of health services use.

Tables 1 and 2 show the prevalence of vertebral deformities by sex and age with respect to number and severity. Overall, the prevalence of having at least one deformity was 39% in both men and women with an age-adjusted sex ratio (women vs. men) of 1.06 (95% CI, 0.74-1.51). The prevalence of vertebral deformity increased with age in both sexes (p < 0.01). In women, the prevalence was highest in the age group ≥ 80 year, whereas in men the prevalence was highest in the age group 75–79 years old. The prevalence of mild and moderate deformities was about similar in men and women, whereas the prevalence of severe deformities was slightly higher in women (12%) than in men (8%). In both men and women, no significant increase in the prevalence of mild and moderate deformities with age was shown, whereas the prevalence of severe deformities rose with age only in women. The prevalence of having one, two, three, or more deformities was similar in men and women. Six percent of the men and 5% of the women had at least three deformities.

Table Table 1.. Prevalence of Vertebral Deformity Classified by Severity According to Age and Sex
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Table Table 2.. Prevalence of Vertebral Deformities Classified by Number According to Age and Sex
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Table 3 presents cut-off points and accompanying frequencies of the functional outcome variables. Mean (SD) for height loss since age 40 was 3.8 (2.9) cm, for peak flow was 442 (132) ml/s in men and 337 (100) ml/s in women, for grip strength was 69.5 (15.1) kg in men and 41.8 (9.2) kg in women, and for performance score was 7.1 (2.8). Median (interquartile range) was for number of difficulties with ADL, 1 (0-2); for physical activity score, 3.5 (2.3-5.0); for pain, 5 (5-6); and for sleeping problems, 6 (4-7).

Table Table 3.. Baseline Characteristics of 527 LASA Participants (267 Women, 260 Men, Age Range 65.3-88.7 Years)
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Table 4 shows the associations between the number of vertebral deformities and 21 different functional outcome measures. In this table, the variables in the first column are the outcome variables. The second column describes the ORs for the number of deformities as a continuous score with each of the outcome variables, adjusted for the potential confounders age, sex, level of education, comorbidity, spinal osteoarthritis, BMI, and smoking. The third, fourth, and fifth columns describe the associations for the number of vertebral deformities as a categorical variable with three dummy variables (one deformity vs. zero deformities, two deformities vs. zero deformities, and three or more deformities vs. zero deformities) and the outcome measures. As can be seen from this table, respondents with multiple deformities reported more often a height loss of more than 5 cm since the age of 40 years than persons with no deformities. When entered as a continuous variable, the number of vertebral deformities, adjusted for potential confounders, was most strongly related to more than 3 days in bed in the past month, more than 3 days with limited activities because of health problems in the past month, and poor self-perceived health. The associations with measures of functional limitations, such as difficulties in ADL and poor performance, in particular difficulties with putting on a cardigan, were weaker but also significant. There were no significant interactions between the number of deformities and sex. When the number of vertebral deformities was treated as a categorical variable with four groups, it was seen that most of the significantly associated outcome measures were most strongly associated with the presence of three or more deformities.

Table Table 4.. Association Between the Number of Prevalent Vertebral Deformities and Functional Outcome Measures Adjusted for Potential Confoundersa
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In Table 5, in the first column, the outcome variables are presented. The second column describes the ORs for the presence of at least one mild deformity compared with the absence of deformity with each of the outcome measures, adjusted for the potential confounders age, sex, level of education, comorbidity, spinal osteoarthritis, BMI, and smoking. The third and fourth columns describe the associations for the presence of at least one moderate deformity, respectively, one severe deformity, compared with the absence of deformity in relation to the outcome measures. Respondents with moderate or severe deformities had lost more height since the age of 40 years compared with those without vertebral deformities. The associations of functional outcome measures with severity of vertebral deformities were generally weaker than those with the number of vertebral deformities. Compared with the absence of deformity, the presence of at least one mild vertebral deformity was not significantly associated with any of the outcome measures. Moderate vertebral deformities were significantly associated with putting on a cardigan and more than 3 days with limited activities in the past month. The presence of a severe deformity was associated with poor performance, in particular a poor chair-stand performance, more than 3 days with limited activities in the past month, and poor self-perceived health. Only for poor performance (in particular poor chair-stand performance), there was a clear threshold at severe deformities in which the association increased strongly. None of the associations was modified by gender. To confirm whether there is a threshold effect only when deformities are very severe, we also compared the presence of vertebral deformities with more than 40% reduction in height (n = 9) to the absence of deformities. Remarkably, a strong significant association with back pain longer than 1 month (OR, 3.23; 95% CI, 1.04-9.99) was found. For the other variables, ORs were similar compared with a cut-off of 30% reduction in vertebral height.

Table Table 5.. Association Between the Severity of Prevalent Vertebral Deformities and Functional Outcome Measures, Adjusted for Potential Confoundersa
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The combination score of number and severity of vertebral deformities was significantly related to height loss since the age of 40 years, poor performance (in particular difficulties with putting on a cardigan and the chair-stand test), more than 3 days in bed in the past month, more than 3 days with limited activities because of health problems in the past month, and poor self-perceived health. However, the ORs were not greater than when a number of deformities as a continuous score was taken as an independent variable. Probably, this may be caused by the fact that 14 of the 29 people with three or more deformities also have the most severe deformities.

The results of multiple regression analysis confirmed the results of logistic regression analyses for both number and severity of the deformities. In line with the logistic regression models, multiple regression analyses revealed that the number of vertebral deformities, entered as a continuous variable, was significantly related to height loss since the age of 40 years (p < 0.001), difficulties with ADL (p = 0.002), poor performance (p = 0.04), and poor self-perceived health (p = 0.007). When the number of deformities was treated as a categorical variable, it was seen that the presence of one deformity compared with the absence of deformity was significantly associated with height loss since the age of 40 years (p = 0.006) and difficulties with ADL (p = 0.03). The presence of two deformities was associated with height loss since the age of 40 years (p = 0.02), difficulties with ADL (p = 0.005), and poor self-perceived health (p = 0.01), whereas the presence of three or more deformities was significantly associated with height loss since the age of 40 years (p = 0.03), difficulties in ADL (p < 0.001), and poor self-perceived health (p = 0.03). In agreement with dichotomous outcome measures, the presence of at least one mild vertebral deformity was not significantly associated with any of the outcome measures. Moderate vertebral deformities were significantly associated with height loss since the age of 40 years only (p = 0.005). In contrast to the logistic regression model, in the multiple regression analyses, the presence of one severe deformity was associated with difficulties in ADL (p = 0.04), whereas it was not associated with poor performance or poor self-perceived health.

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

We found that vertebral deformities are very common in older people. The prevalence was very similar in both sexes, confirming results of other studies.(2) The prevalence of having at least one vertebral deformity was 39% in both men and women aged 65 years and older. Although the prevalence of three or more deformities also was approximately similar for men (5.8%) and women (5.2%), the prevalence of severe deformity was slightly higher in women (12.4%) than in men (7.7%). For both sexes, the prevalence of mild and moderate deformities did not increase with age, whereas the prevalence of severe deformities rose with age only in women. In addition, we observed that vertebral deformities are associated with impairments, functional limitations, disability, and impaired well-being and that these associations depend both on the number of vertebral deformities and on their severity. Having three or more deformities or at least one moderate deformity may result in a substantially reduced level of functioning. Furthermore, these associations did not seem to depend on gender.

One of the strengths of this study is that it included men as well as women. It is remarkable that both the prevalence and the impact of vertebral deformities were very similar in both sexes. Most previous studies examined the prevalence and consequences of vertebral deformities only in women. Another strong point is that this study included a variety of measures representing different levels of functioning. In addition to functional limitations, associations with disability, well-being, and health services use also were examined and appeared to be important. Until now, these aspects of functioning did not get much attention.

Comparison of these prevalences with those found in other studies is difficult. There is no gold standard for defining vertebral deformity and prevalences therefore depend on the various methods and criteria used. In our study, the presence of vertebral deformities was assessed by an experienced clinician using a semiquantitative method. The advantage of this method is that experts are able to discriminate between anatomical variants and technical artifacts on the photographs that are often not captured by a morphometric method.(21,37) Our results agree rather well with those found by Genant et al.(38) who compared the prevalences of semiquantitative and quantitative assessments in a population sample of 503 American women with an age range of 65–88 years. Semiquantitative assessment revealed that 33% of the women had at least one vertebral deformity (at least 20% vertebral height loss) and 14% of them had at least a vertebral deformity of grade 2 (25-30% vertebral height loss).

The finding that the prevalence of having at least one vertebral deformity was similar in men and women confirms the results of O'Neill et al.,(2) who compared prevalences measured with the methods of both Eastell(39) and McCloskey(40) in a large multicenter European study. They found that the prevalence of vertebral deformities across all countries was similar in men and women but that there was a large geographic variation for the sex ratio within Europe. Our finding that severe deformities are more frequent in women compared with men agrees with the results of Burger et al.(6) However, in their study these differences were more pronounced.

The finding that the number of vertebral deformities is related to height loss and functional limitations, such as difficulty with ADL and performance, confirms the results of several previous studies(5,8,9,16,17) but disagrees with the study of Burger et al.(6) who did not find a consistent relationship between the number of deformities and functional impairment. The impact of the number of vertebral deformities on disability and well-being confirms the results of recent studies on functional disability and quality of life.(4,41) In a prospective study, Nevitt et al.(4) found that the number days of bed rest per year and the number of days with limited activity increased strongly with the number of incident vertebral fractures. Silverman et al.(42) also found that health-related quality of life (HRQOL) started to decrease substantially at a threshold of three vertebral deformities.

In contrast to other studies, we found that several measures of functioning were as strongly associated with the presence of a moderate deformity as with the presence of a severe deformity. At least two studies(6,16) reported that especially severe deformities were associated with functional outcome. However, in a small sample we found that, in particular, back pain became an important problem only in people with very severe deformities (>40% reduction in vertebral height), which agrees with the findings of Ettinger et al.(17) They showed that women with very severe deformities had increased risk of back pain and disability involving the back.

This study has several limitations. First, the data are cross-sectional and do not allow causal inference. We are not able to verify whether vertebral deformities preceded diminished level of functioning or vice versa. In addition, cross-sectional data do not distinguish recent deformities from deformities that occurred several years ago. This makes it impossible to examine changes in functioning that followed in the period right after the occurrence of the vertebral deformity. Currently, longitudinal data are being collected to address these questions. Second, nonresponse was associated with most of the outcome measures; frail respondents were less likely to participate in the medical interview and to visit the hospital. Because they may have the more severe and the higher number of vertebral deformities, as is indicated by the greater height loss since the age of 40 years, prevalences and associations might have been underestimated. Third, because margins of the vertebrae on radiographs were in some cases difficult to identify because of imaging artifacts, parallax distortion, radiographic quality, or spinal osteoarthritis, nondifferential misclassification might have occurred. This also might have resulted in an underestimation of the observed associations. Finally, although we adjusted for several important confounders such as comorbidity, we cannot rule out the possibility of residual confounding in this observational study. Some of the relationships investigated in this study might have been affected by other measures of frailty than the ones that we have included in the analyses, such as, for example, other back-related disorders.

We can conclude that vertebral deformities are very common in both older men and older women. Vertebral deformities, even if they are not clinically manifest, have substantial consequences. Persons with multiple or severe vertebral deformities spend more days in bed, are limited in performing activities, and report poor self-perceived health. Appropriate treatment, including physical therapy and medication, may improve their level of daily functioning and quality of life.

Acknowledgements

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

This work could not have been completed without the assistance of Nel van de Kreeke, Els Lommerse, Mariëtte Westendorp-de Serière, and Jan Poppelaars and the useful advice of Marjolein Visser and Vianda Stel. This study is based on data collected in the context of the LASA, which is largely funded by the Ministry of Health, Welfare, and Sports of the Netherlands.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES
  • 1
    Melton LJ III, Lane AW, Cooper C, Eastell R, O'Fallon WM, Riggs BL 1993 Prevalence and incidence of vertebral deformities. Osteoporos Int 3:113119.
  • 2
    O'Neill TW, Felsenberg D, Varlow J, Cooper C, Kanis JA, Silman AJ 1996 The prevalence of vertebral deformity in european men and women: The European Vertebral Osteoporosis Study. J Bone Miner Res 11:10101018.
  • 3
    Cooper C, Atkinson EJ, O'Fallon WM, Melton LJ III 1992 Incidence of clinically diagnosed vertebral fractures: A population-based study in Rochester, Minnesota, 1985–1989. J Bone Miner Res 7:221227.
  • 4
    Nevitt MC, Ettinger B, Black DM, Stone K, Jamal SA, Ensrud K, Segal M, Genant HK, Cummings SR 1998 The association of radiographically detected vertebral fractures with back pain and function: a prospective study. Ann Intern Med 128:793800.
  • 5
    Huang C, Ross PD, Wasnich RD 1996 Vertebral fractures and other predictors of back pain among older women. J Bone Miner Res 11:10261032.
  • 6
    Burger H, Van Daele PLA, Grashuis K, Hofman A, Grobbee DE, Schütte HE, Birkenhäger JC, Pols HAP 1997 Vertebral deformities and functional impairment in men and women. J Bone Miner Res 12:152157.
  • 7
    Lyles KW, Gold DT, Shipp KM, Pieper CF, Martinez S, Mulhausen PL 1993 Association of osteoporotic vertebral compression fractures with impaired functional status. Am J Med 94:595601.
  • 8
    Ross PD, Ettinger B, Davis JW, Melton LJ III, Wasnich RD 1991 Evaluation of adverse health outcomes associated with vertebral fractures. Osteoporos Int 1:134140.
  • 9
    Huang C, Ross PD, Wasnich RD 1996 Vertebral fracture and other predictors of physical impairment and health care utilization. Arch Intern Med 156:24692475.
  • 10
    Gold DT, Smith SD, Bales CW, Lyles KW, Westlund RE, Drezner MK 1991 Osteoporosis in late life: does health locus of control affect psychosocial adaptation? J Am Geriatr Soc 39:670675.
  • 11
    Lips P, Cooper C, Agnusdei D, Caulin F, Egger P, Johnell O, Kanis JA, Liberman U, Minne H, Reeve J, Reginster JY, de Vernejoul MC, Wiklund I 1997 Quality of life as outcome in the treatment of osteoporosis: The development of a questionnaire for quality of life by the European Foundation for Osteoporosis. Osteoporos Int 7:3638.
  • 12
    Lips P, Cooper C, Agnusdei D, Caulin F, Egger P, Johnell O, Kanis JA, Kellingray S, Leplege A, Liberman UA, McCloskey E, Minne H, Reeve J, Reginster JY, Scholz M, Todd C, de Vernejoul MC, Wiklund I 1999 Quality of life in patients with vertebral fractures. Validation of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO). Osteoporos Int 10:150160.
  • 13
    Gold DT 1996 The clinical impact of vertebral fractures: Quality of life in women with osteoporosis. Bone 18:185S189S.
  • 14
    Kanis JA, Minne WH, Meunier PJ, Ziegler R, Allender E 1992 Quality of life and vertebral osteoporosis. Osteoporos Int 2:161163.
  • 15
    Greendale GA, Silverman SL, Hays RD, Cooper C, Spector T, Kiel D, Reuben DB 1993 Health-related quality of life in osteoporosis clinical trials. Calcif Tissue Int 53:7577.
  • 16
    Spector TD, McCloskey EV, Doyle DV, Kanis JA 1993 Prevalence of vertebral fracture in women and the relationship with bone density and symptoms: The Chingford Study. J Bone Miner Res 8:817822.
  • 17
    Ettinger B, Black DM, Nevitt MC, Rundle AC, Cauley JA, Cummings SR, Genant HK 1992 Contribution of vertebral deformities to chronic back pain and disability. J Bone Miner Res 7:449456.
  • 18
    Leidig G, Minne HW, Sauer P, Wüster C, Wüster J, Lojen M, Raue F, Ziegler R 1990 A study of complaints and their relation to vertebral destruction in patients with osteoporosis. Bone Miner 8:217229.
  • 19
    DeegDJH, KnipscheerCPM, Van TilburgW (eds.) 1993 Autonomy and Well-Being in the Aging Population: Concepts and Design of the Longitudinal Aging Study Amsterdam. Netherlands Institute of Gerontology, Bunnik, The Netherlands.
  • 20
    Smit JH, De Vries MZ 1994 Procedures and results of the field work. In: DeegDJH, Westendorp-de SeriereM (eds.) Autonomy and Well-Being in the Aging Population I: Report from the Longitudinal Aging Study Amsterdam 1992–1993. VU University Press, Amsterdam, The Netherlands, pp. 713.
  • 21
    Genant HK, Wu CY, van Kuijk C, Nevitt MC 1993 Vertebral fracture assessment using a semiquantitative technique. J Bone Miner Res 8:11371148.
  • 22
    Landis JR, Koch GG 1977 The measurement of observer agreement for categorical data. Biometrics 33:159174.
  • 23
    Altman DG 1991 Practical Statistics for Medical Research. Chapman & Hall, London, U.K.
  • 24
    Verbrugge LM, Jette AM 1994 The disablement process. Soc Sci Med 38:114.
  • 25
    Wood PHN 1980 Appreciating the consequences of disease: The international classification of impairments, disabilities and handicaps. WHO Chronicle 34:376380.
  • 26
    Hosmer DW, Lemeshow S 1989 Applied Logistic Regression. John Wiley & Sons, Inc., New York, NY, U.S.A.
  • 27
    Van Sonsbeek JLA 1988 Methodological and substantial aspects of the OECD indicator of chronic functional limitations. Maandbericht Gezondheid (CBS) 88:417.
  • 28
    Kriegsman DMW, Deeg DJH, van Eijk JThM, Penninx BWJH, Boeke AJP 1997 Do disease specific characteristics add to the explanation of mobility limitations in patients with different chronic diseases? A study in the Netherlands. J Epidemiol Community Health 51:676685.
  • 29
    Guralnik JM, Simonsick EM, Ferrucci L, Glynn RJ, Berkman LF, Blazer DG, Scherr PA, Wallace RB 1994 A short physical performance battery assessing lower extremity function: association with self-reported disability and prediction of mortality and nursing home admission. J Gerontol 49:M85M94.
  • 30
    Anderson JST, Sulivan F, Usherwood TP 1990 The Medical Outcome Study instrument (MOSI). Use of a new health status measure in Britain. Fam Pract 7:205218.
  • 31
    Voorrips LE, Ravelli ACJ, Dongelmans PCA, Deurenberg P, Van Staveren WA 1991 A physical activity questionnaire for the elderly. Med Sci Sports Exerc 23:974979.
  • 32
    Caspersen CJ, Bloemberg BP, Saris WH, Merritt RK, Kromhout D 1991 The prevalence of selected physical activities and their relation with coronary heart disease risk factors in elderly men: The Zutphen Study, 1985. Am J Epidemiol 133:10781092.
  • 33
    Netherlands Central Bureau of Statistics 1989 Health Interview Questionnaire. Central Bureau of Statistics, Heerlen, the Netherlands.
  • 34
    Hunt SM, McEwen J, McKenna SP 1985 Measuring health status: A new tool for clinicians and epidemiologists. J R Coll Gen Pract 35:185188.
  • 35
    Radloff LS 1977 The CES-D scale: A self-report depression scale for research in the general population. Appl Psychol Meas 3:385401.
  • 36
    Kriegsman DMW, Penninx BWJH, Eijk van JTM, Boeke AJP, Deeg DJH 1996 Self-reports and general practitioner information on the presence of chronic diseases in community-dwelling elderly: A study on the accuracy of patients' self-reports and on determinants of inaccuracy. J Clin Epidemiol 49:14071417.
  • 37
    National Osteoporosis Foundation Working Group on Vertebral Fractures 1995 Report assessing vertebral fractures. J Bone Miner Res 10:518523.
  • 38
    Genant HK, Jergas M, Palermo L, Nevitt M, Valentin RS, Black D, Cummings SR 1996 Comparison of semiquantitative visual and quantitative morphometric assessment of prevalent and incident vertebral fractures in osteoporosis. J Bone Miner Res 11:984996.
  • 39
    Eastell R, Cedel SL, Wahner HW, Riggs BL, Melton LJ III 1991 Classification of vertebral fractures. J Bone Miner Res 6:207215.
  • 40
    McCloskey EV, Spector TD, Eyres KS, Fern ED, O'Rourke N, Vasikaran S, Kanis JA 1993 The assessment of vertebral deformity: A method for use in population studies and clinical trials. Osteoporos Int 3:138147.
  • 41
    Oleksik A, Moseley E, Dawson A, Minshall M, Lips P 1998 The impact on health-related quality of life (HRQOL) in postmenopausal women with low BMD and prevalent fractures. J Bone Miner Res 23:S398. (abstract)
  • 42
    Silverman SL, Minshall ME, Shen W, Harper KD, Xie S 1998 The impact of vertebral fracture(s) on health related quality of life (HRQOL) in established postmenopausal osteoporosis depends on the number and location of the fracture(s). J Bone Miner Res 23:S305. (abstract)