Biomedical subjects

M C Nevitt

Publications and source records attributed to M C Nevitt.

At least 109 records · Page 6Linked to original sources

PubMed1993

Type of fall and risk of hip and wrist fractures: the study of osteoporotic fractures. The Study of Osteoporotic Fractures Research Group.

OBJECTIVE: To determine the causes of hip or wrist fractures. DESIGN: Case-control analysis nested in a prospective cohort study. SETTING: Four clinical centers in Baltimore, Maryland, Minneapolis, Minnesota, Portland, Oregon, and Monessen, Pennsylvania. PARTICIPANTS: Non-black women age 65 and older living in the community. MEASUREMENTS: We measured bone density, arm strength, and anthropometric characteristics at a baseline examination. Those who subsequently suffered hip (n = 130) or wrist (n = 294) fractures as a result of a fall and a consecutive sample of those who fell without a fracture (n = 467) were interviewed about their falls. RESULTS: In multivariate analyses, those who suffered hip fractures were more likely to have fallen sideways or straight down (odds ratio 3.3; 95% confidence interval 2.0 to 5.6) and to have landed on or near the hip (32.5; 9.9, 107.1) than women who fell without a fracture. Among women who fell on the hip, those with hip fractures were taller (1.5; 1.2, 2.2 per SD increase), less likely to have landed on a hand (0.3; 0.1 to 0.6) or to break the fall by grabbing or hitting an object (0.4; 0.2, 0.9), had weaker triceps (1.7; 1.2, 2.5 per SD decrease), and were more likely to land on a hard surface (2.8; 1.4, 5.5) than those without fractures. Women with wrist fractures were more likely to have fallen backward (2.2; 1.3, 3.8) and to have landed on a hand (20.4; 11.5, 36.0) than those who fell without a fracture. Among women who fell on the hand, those with wrist fractures were taller (1.4; 1.1, 1.8 per SD increase) and less likely to break the fall by grabbing or hitting an object (0.4; 0.2, 0.7). Among women who fell on their hip or hand, the risk of fracturing that site more than doubled for each standard deviation decrease in bone density at the site of fracture. CONCLUSIONS: The nature of the fall determines the type of fracture, while bone density and factors that increase or attenuate the force of impact of the fall determine whether a fracture will occur when a faller lands on a particular bone. These findings have important implications for prevention of fractures in older women.

Accidental Falls↗

PubMed1993

Association between low bone density and stroke in elderly women. The study of osteoporotic fractures.

BACKGROUND AND PURPOSE: To determine whether women with low bone mineral density are at increased risk of stroke, the present study was conducted. METHODS: We studied 4024 ambulatory women aged 65 years or older participating in the prospective Study of Osteoporotic Fractures. Bone mineral density was measured at baseline using single photon absorptiometry; strokes were ascertained using a computerized Medicare data base and death certificates. RESULTS: During a mean of 1.98 years of follow-up, 83 women suffered first strokes (five fatal). Osteopenia was associated with an increased stroke risk: Each SD decrease in bone mineral density at the calcaneus (0.09 g/cm2) was associated with a 1.31-fold increase in stroke (95% confidence interval, 1.03-1.65), adjusted for age, follow-up time, and several potential confounders, including diabetes, systolic blood pressure, use of alcohol, cigarettes or postmenopausal estrogens, cognitive ability, grip strength, and functional ability. The observed relation between bone density and stroke was strongest for intracerebral hemorrhages and occlusions. CONCLUSIONS: Most likely, low bone density does not cause stroke; some other process probably results in both osteopenia and cerebrovascular disease.

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PubMed1993

Reliability of new indices of radiographic osteoarthritis of the hand and hip and lumbar disc degeneration.

OBJECTIVE: To develop a method for assessing the presence and severity of radiographic features of osteoarthritis (OA) of the hip and hand, and thoracic and lumbar disc degeneration. METHODS: An atlas illustrating scoring of individual radiographic features and summary grades for individual joints was developed. Three readers evaluated 31 pelvic films, 27 hand films, and 25 lateral lumbar and thoracic spine films selected from a community based sample of healthy elderly women. Interrater agreement between the 3 readers, and test-retest agreement for one of the readers, were estimated by the intraclass correlation coefficient (ICC) and kappa statistic. RESULTS: Interrater agreement (ICC, unless otherwise noted) for individual radiographic features of the hip ranged from 0.66 for osteophytes to 0.80 for narrowing. For the 9 interphalangeal (IP) joints of the hand, agreement ranged from 0.42 (kappa) for sclerosis to 0.93 for narrowing, and for the lumbar spine from 0.55 (kappa) for sclerosis to 0.95 for narrowing. Interrater agreement for summary grades of radiographic findings was as follows: hip, 0.81; 5 distal interphalangeal joints (DIP), 0.89; 4 proximal interphalangeal joints (PIP), 0.82; and lumbar spine, 0.93. Intrarater agreement for summary grades was as follows: hips, 0.79; 5 DIP, 0.86; 4 PIP, 0.81; and lumbar spine, 0.90. CONCLUSION: We have developed reliable indices of the presence and severity of radiographic features of hip and hand OA and spinal disc degeneration for use in epidemiologic studies. The assessment includes grading of individual radiographic features, which allows for the independent variation in these features often found in OA and a summary grade of disease that is derived from the presence and severity of individual features.

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PubMed1993

Serum sex hormones and severity of osteoarthritis of the hand.

OBJECTIVE: To examine the relationship of endogenous sex hormones to the severity of radiographic hand osteoarthritis (ROA) in 229 white women, mean age 74 years. METHODS: Hand ROA was graded according to the Kellgren-Lawrence scale and according to individual features of OA: osteophytes, joint space narrowing, subchondral sclerosis, lateral deformity and joint collapse. Two measures of hand ROA were considered: the worst joint score assigned to any one of 10 hand joints and the sum of the scores for the 10 joints. RESULTS: Comparison of the age and obesity adjusted sex hormone concentrations by the worst Kellgren-Lawrence score or the worst score of the individual features of OA revealed little difference. There were no trends in the sex hormone concentrations with increasing severity of hand ROA. CONCLUSIONS: Our results do not support an association between endogenous hormone levels and severity of hand ROA.

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PubMed1992

Risk factors for fractures of the distal forearm and proximal humerus. The Study of Osteoporotic Fractures Research Group.

The Study of Osteoporotic Fractures is a prospective cohort study begun in 1986 that includes 9,704 women aged 65 years and older from Maryland, Minnesota, Oregon, and Pennsylvania. A total of 171 women suffered fractures of the distal forearm, and 79 women had fractures of the proximal humerus during the first 2.2 years of follow-up. Most fractures at both sites occurred as a result of a fall. Low bone mineral density was a strong predictor of these fractures; comparing those in the lowest quintile of bone mineral density in the distal radius with those in the highest quintile, the rate ratio was 4.1 for fractures of the distal forearm and 7.5 for fractures of the proximal humerus. Other factors associated with an increased rate of distal forearm fracture independently of low bone mineral density included poor visual acuity, number of falls in the year before baseline, and frequent walking. Factors that appeared to be independently associated with an increased rate of fracture of the proximal humerus included a recent decline in health status, insulin-dependent diabetes mellitus, infrequent walking, and several indicators of neuromuscular weakness such as inability to stand with feet in a tandem position for more than a few seconds. These data support the hypothesis that distal forearm fractures often occur as a result of a fall in women with low bone mineral density who are relatively healthy and active and have good neuromuscular function, while fractures of the proximal humerus tend to occur as a result of a fall in women with low bone mineral density who are less healthy and less active than average and who have poor neuromuscular function.

Age Factors↗

PubMed1992

The accuracy of self-report of fractures in elderly women: evidence from a prospective study.

The authors compared self-reports of non-spine fractures in a cohort of elderly white women with radiologic reports and medical records. Subjects (n = 9,704) were recruited between 1986 and 1988 in Baltimore, Pittsburgh, Minneapolis, and Portland, Oregon. Eleven percent (95% confidence interval 9-13%) of self-reports of fracture were false-positive (radiographs were negative) and a total of 20% (18-23%) could not be confirmed (radiographs were negative, uncertain, or not available). Report by proxy respondent was more accurate than self-report. There were no confirmed fractures in the medical records of a random sample of 283 participants who did not report a fracture. The percent of false-positives varied by the site of the injury and was low for self-reported fractures of the shoulder or upper arm (5%; 1-13%), wrist (8%; 4-11%), and hip (11%; 5-19%), but was high for hand or finger (20%; 12-30%), rib (23%; 15-32%), and face or skull (33%; 17-54%). Having a college education was associated with increased accuracy, while a history of falls and self-reported osteoporosis were associated with decreased accuracy. The authors conclude that elderly women overreport fractures, but that self-report is relatively accurate for several important osteoporotic fractures, including those of the hip, wrist, and humerus. Self-report of "any" fracture, rib, distal extremity, and head fracture, and fractures in women with a tendency to fall or with osteoporosis should be verified by a radiologic diagnosis.

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PubMed1992

Contribution of vertebral deformities to chronic back pain and disability. The Study of Osteoporotic Fractures Research Group.

Among 2992 white women aged 65-70 years recruited from population-based listings, we measured radiographic vertebral dimensions of T5-L4 and calculated ratios of heights: anterior/posterior, mid/posterior, and posterior/posterior of either adjacent vertebra. The degree of deformity for each vertebra was analyzed in terms of the number of standard deviations (SD) that ratio differed from the mean ratio calculated for the same vertebral level in this population. We correlated the severity of each woman's worst vertebral deformity with back pain, back disability in six activities of daily living, and height loss since age 25. Only 39.4% of the cohort had no vertebral deformity; 10.2% had a deformity greater than or equal to 4 SD. Vertebral deformities less than 4 SD below the mean were not associated with increased back pain, disability, or loss of height. In contrast, women whose deformity was greater than or equal to 4 SD had a 1.9 (95% CI, 1.5-2.4) times higher risk of moderate to severe back pain and a 2.6 (95% CI, 1.7-3.9) times higher risk of disability involving the back; they were also 2.5 (95% CI, 2.0-3.2) times more likely to have lost greater than or equal to 4 cm in height. All three types of vertebral deformity (wedge, end plate, and crush) were equally associated with these outcomes. Multiple deformities less than 4 SD did not increase the likelihood of these three outcomes, but multiple deformities greater than or equal to 4 SD tended to be associated with increased back pain, disability, and height loss. This large cross-sectional study suggests that vertebral deformities cause substantial pain, disability, or loss of height only if vertebral height ratios fall 4 SD below the normal mean. Much back pain could not be attributed to vertebral deformities, suggesting other causes.

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PubMed1992

Axial and appendicular bone density predict fractures in older women.

To determine whether measurement of hip and spine bone mass by dual-energy x-ray absorptiometry (DEXA) predicts fractures in women and to compare the predictive value of DEXA with that of single-photon absorptiometry (SPA) of appendicular sites, we prospectively studied 8134 nonblack women age 65 years and older who had both DEXA and SPA measurements of bone mass. A total of 208 nonspine fractures, including 37 wrist fractures, occurred during the follow-up period, which averaged 0.7 years. The risk of fracture was inversely related to bone density at all measurement sites. After adjusting for age, the relative risks per decrease of 1 standard deviation in bone density for the occurrence of any fracture was 1.40 for measurement at the proximal femur (95% confidence interval 1.20-1.63) and 1.35 (1.15-1.58) for measurement at the spine. Results were similar for all regions of the proximal femur as well as SPA measurements at the calcaneus, distal radius, and proximal radius. None of these measurements was a significantly better predictor of fractures than the others. Furthermore, measurement of the distal radius was not a better predictor of wrist fracture (relative risk 1.64: 95% CI 1.13-2.37) than other sites, such as the lumbar spine (RR 1.56; CI 1.07-2.26), the femoral neck (RR 1.65; CI 1.12-2.41), or the calcaneus (RR 1.83; CI 1.26-2.64). We conclude that the inverse relationship between bone mass and risk of fracture in older women is similar for absorptiometric measurements made at the hip, spine, and appendicular sites.

Absorptiometry, Photon↗

PubMed1992

Postural hypotension and postural dizziness in elderly women. The study of osteoporotic fractures. The Study of Osteoporotic Fractures Research Group.

BACKGROUND: Postural hypotension and dizziness are common findings in elderly individuals. Although postural hypotension and postural dizziness are often perceived to be strongly associated entities, evidence to support this view in sparse. In addition, there is a lack of knowledge regarding the relationship of postural hypotension and postural dizziness to potential clinical outcomes, such as falls, syncope, and restricted activity. METHODS: We utilized a cross-sectional examination to study the prevalence and correlates of postural hypotension (drop in systolic blood pressure of greater than or equal to 20 mm Hg after 1 minute of standing) and postural dizziness (self-reported dizziness on standing) in 9704 nonblack, ambulatory women aged 65 years and older enrolled in the multicenter Study of Osteoporotic Fractures. First, we examined postural hypotension and postural dizziness as outcomes of risk factors that included medical conditions, medications, and physical findings. Then, we examined falls, syncope, and impaired functional status as outcomes of postural hypotension and postural dizziness. RESULTS: Postural hypotension and postural dizziness were common findings, noted in 14% and 19% of subjects, respectively. However, they were not highly correlated with each other and did not share the same risk factors or associated outcomes. Postural dizziness was more strongly associated than was postural hypotension with history of falling (age-adjusted odds ratios, 1.32 vs 1.02), history of syncope (1.94 vs 1.35), and impaired functional status (1.95 vs 0.76). CONCLUSION: Assessment of dizziness on standing appears to be more important than measurement of postural blood pressure change in ascertaining functional status and risk of falls and syncope in elderly individuals. Future prospective studies of postural dizziness are needed to confirm its value as a predictor of clinical outcomes.

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PubMed1991

Which fractures are associated with low appendicular bone mass in elderly women? The Study of Osteoporotic Fractures Research Group.

OBJECTIVE: To determine which types of fractures have an increased incidence in elderly women with low appendicular bone mass. DESIGN: Prospective cohort study. SETTING: Four clinical centers in the United States (Baltimore, Maryland; Minneapolis, Minnesota; Portland, Oregon; Monangehela Valley, Pennsylvania); and one coordinating center in San Francisco, California. SUBJECTS: Ambulatory, nonblack women (9704) aged 65 years or more who were recruited from population-based listings. MEASUREMENTS: We measured bone mass at the distal and proximal radius and calcaneus using single-photon absorptiometry. Fractures were verified radiographically. Associations were calculated as age-adjusted hazard ratios (with 95% Cls) per standard deviation decrease in bone mass. MAIN RESULTS: During a mean follow-up of 2.23 years, 841 nonspinal fractures occurred in 753 women. The risks for fractures of the wrist, foot, humerus, hip, rib, toe, leg, pelvis, hand, and clavicle were significantly related to reduced bone mass (P less than 0.05). These fractures represented 74% of nonspinal fractures. The overall hazard ratio for the occurrence of one or more of these fractures was 1.65 (Cl, 1.49 to 1.82) at the distal radius. In a subsample of the cohort, vertebral fractures were also related to low bone mass. Fractures of the ankle, elbow, finger, and face, however, were not associated with bone mass at any measurement site; the overall hazard ratio for these fractures was 1.12 (Cl, 0.96 to 1.30) at the distal radius. CONCLUSION: Most types of fractures have an increased incidence in elderly women with low bone mass.

Age Factors↗

PubMed1991

Risk factors for injurious falls: a prospective study.

We conducted a prospective study of the consequences of falls in 325 elderly community-dwelling persons, all of whom had fallen in the previous year. We contacted subjects every week for one year to ascertain falls and to determine the circumstances and consequences of falls. Only 6% of 539 falls resulted in a major injury (fracture, dislocation, or laceration requiring suture), but over half (55%) resulted in minor soft tissue injury. One in ten falls left the faller unable to get up for at least 5 minutes, and one in four falls caused subjects to limit their activities. The risk of injury per fall was about the same regardless of the number of falls a person had during follow-up. The risk of major injury was increased (age- and sex-adjusted odds ratio: 5.9, 95% confidence interval: 2.3-14.9) in falls associated with loss of consciousness compared to nonsyncopal falls. In multivariate analyses of nonsyncopal falls, the risk of major injury per fall was higher in persons having a previous fall with fracture (6.7; 2.1-21.5), a slower Trail Making B time (1.9; 1.1-3.2), and in Whites (18.4; 7.5-44.6). The risk that a nonsyncopal fall would result in minor injury (versus no injury) was increased in persons with a slower hand reaction time (1.8; 1.0-3.2) decreased grip strength (1.5; 1.0-2.3), in Whites (2.0; 1.0-3.7), in falls while using stairs and steps (2.2; 1.0-5.0), and turning around or reaching (3.5; 1.7-7.3). Our findings suggest that neuromuscular and cognitive impairment, as well as the circumstances of falls, affect the risk of injury when a fall occurs.

Accidental Falls↗

PubMed1990

Appendicular bone density and age predict hip fracture in women. The Study of Osteoporotic Fractures Research Group.

To determine whether measurement of bone density predicts hip fracture in women, we prospectively studied 9703 nonblack women aged 65 years and older who had measurements of bone mineral density using single-photon absorptiometry in the calcaneus, distal radius, and proximal radius. During an average of 1.6 years of follow-up, 53 hip fractures occurred. The risk of hip fracture was inversely related to bone density at all three measurement sites. After adjusting for age, the relative risk of hip fracture was 1.66 for a decrease of 1 SD in the bone density at the calcaneus (95% confidence interval, 1.22 to 2.26), 1.55 (95% confidence interval, 1.13 to 2.11) at the distal radius, and 1.41 (95% confidence interval, 1.06 to 1.88) at the proximal radius. None of the three measurements was a significantly better predictor of hip fracture than the others. After adjusting for bone mineral density, the risk of hip fracture doubled for each 10-year increase in age (relative risk, 2.09; 95% confidence interval, 1.31 to 3.33). We conclude that decreased bone density in the appendicular skeleton is associated with an increased risk of hip fracture, but this accounts for only part of the age-related increase in risk of hip fracture among older women.

Age Factors↗

PubMed1990

Methodologic issues in the study of frequent and recurrent health problems. Falls in the elderly.

In this paper the example of falls in the elderly is used to demonstrate methodologic difficulties that arise in the epidemiologic study of frequent and recurrent health problems. Issues discussed include whether the relevant outcome is the state of being a faller or the rate at which falls occur, misclassification of self-reported outcome data, the inadequacies of current terminology for describing certain study types and measures of frequency and effect from studies of recurrent events, the potential for outcome to influence exposure status in cohort studies of recurrent health problems, and the question of controlling for falls occurring prior to the study period. It is concluded that epidemiology needs to develop a framework for studying frequent and recurrent health problems.

Accidental Falls↗

PubMed1989

Risk factors for recurrent nonsyncopal falls. A prospective study.

Falls are a major threat to the health of older persons. We evaluated potential risk factors for falls in 325 community-dwelling persons aged 60 years or older who had fallen during the previous year, then followed up weekly for 1 year to ascertain nonsyncopal falls and their consequences. Risk factors for having a single fall were few and relatively weak, but multiple falls were more predictable. In multivariate analyses, we found increased odds of two or more falls for persons who had difficulty standing up from a chair, difficulty performing a tandem walk, arthritis, Parkinson's disease, three or more falls during the previous year, and a fall with injury during the previous year, and for whites. The proportion of subjects with two or more falls per year increased from 0.10 for those with none or one of these risk factors to 0.69 for those with four or more risk factors. Among older persons with a history of a recent fall, the risk of multiple nonsyncopal falls can be predicted from a few simple questions and examinations.

Accidental Falls↗

PubMed1989

Work disability among cancer patients.

To identify factors affecting the ability of persons with recent cancer diagnoses to remain in the labor force and retain premorbid levels of work performance, the investigators analyzed data on 247 individuals with lung, pancreatic, prostatic, or cervical cancer. Subjects were selected from a population-based tumor registry. According to Pearson correlations, ordinary least squares multiple regression, and logistic analysis, physical factors related to disease were the strongest predictors of work disability, defined as either leaving the labor force or functioning less fully at work than before becoming ill. The strongest predictors of work disability were physical dysfunction measured by the Sickness Impact Profile (SIP) and disease stage. Social background factors such as age, sex, income, and education were not statistically significant predictors. Two job characteristics, (1) physical demands of work and (2) discretion over hours worked and how much work would be done, predicted work disability, the latter appearing to help prevent this condition. Strictly disease-related factors appear more important here in predicting work disability than in studies of other diseases. Still, it appears that increasing flexibility of working hours and the pace of work could help some individuals with cancer histories remain in the labor force. Unwillingness of employers to facilitate such accommodation where technically feasible may constitute a form of discrimination against the cancer patient.

Activities of Daily Living↗

PubMed1989

A hypothesis: the causes of hip fractures.

Neither age-related osteoporosis nor the increasing incidence of falls with age sufficiently explain the exponential increase in the incidence of hip fracture with aging. We propose that four conditions must be satisfied in order for a fall to cause a hip fracture: (a) the faller must be oriented to impact near the hip; (b) protective responses must fail; (c) local soft tissues must absorb less energy than necessary to prevent fracture, and (d) the residual energy of the fall applied to the proximal femur must exceed its strength. All of these events become more likely with aging and lead to an exponential rise in the risk of hip fracture with advancing age. This model also suggests that a combination of measurements of neuromuscular function and of bone strength may be the most accurate approach to assessing the risk of hip fracture.

Accidental Falls↗

PubMed1988

Forgetting falls. The limited accuracy of recall of falls in the elderly.

To determine how accurately elderly subjects recall recent falls, we studied 304 ambulatory men and women over the age of 60 years who completed a 12-month prospective study of risk factors for falling. We developed a system of weekly follow-up and home visits to record and confirm all falls. During the study, 179 participants suffered at least one fall that was confirmed by home visit. At the end of the study, all subjects were interviewed by telephone about whether they had suffered a fall during the preceding 3, 6, or 12 months. Depending on the time period of recall, 13% to 32% of those with confirmed falls did not recall falling during the specific period of time. Recall was better for the preceding 12 months than for 3 or 6 months. There were only weak correlations (r = 0.28 to 0.59) between the number of falls that were documented and the number that the subjects recalled during each of these periods. Those with lower scores on the Mini-Mental State Examination were more likely to forget falls. We conclude that elderly subjects often do not recall falls that occurred during specific periods of time over the preceding 3 to 12 months. Researchers and clinicians should consider using methods besides long-term recall for ascertaining and counting falls over specific periods of time.

Accidental Falls↗

PubMed1986

Risk factors for hospitalization and surgery in patients with rheumatoid arthritis: implications for capitated medical payment.

Risk factors for hospitalization in patients with rheumatoid arthritis were analyzed to determine if factors proposed for use in adjusting Medicare capitation payments to prepaid health plans are, in fact, associated with use of costly medical care for this illness. Participating physicians from a random sample of half the rheumatologists in northern California provided us with the names of all patients with rheumatoid arthritis presenting during a 1-month period. We surveyed 754 (89%) of these patients in both 1982-83 and 1984 to obtain information about health care use in the previous 12 months. We found that baseline functional status and prior-year admissions (proposed Medicare adjustment factors), as well as disease-specific severity measures, predicted subsequent admissions. The association of prior with subsequent admissions was independent of disease severity and physician characteristics. Adjusting capitation payments for both health status and prior use will increase incentives for prepaid health plans to enroll patients with rheumatoid arthritis who have high expected medical costs.

Arthritis, Rheumatoid↗