Fredric D. Wolinsky

Quadriceps Weakness and Osteoarthritis of the Knee

Osteoarthritis of the knee is the most common cause of chronic disability among older persons in the United States [1]. In persons with symptomatic osteoarthritis of the knee, quadriceps muscle weakness is common and is widely believed to result from disuse atrophy secondary to joint pain. Although exercises to strengthen the quadriceps may relieve joint pain in persons with osteoarthritis of the knee [2-6], the role of periarticular muscle weakness in the pathogenesis of joint pain and disability in these persons is poorly understood. The basis for the beneficial effect of strengthening exercises is unclear, and the duration of the improvement has not been studied. Furthermore, the possibility that muscle weakness is an etiologic factor underlying the pathologic changes of osteoarthritis has seldom been considered. Elucidation of the role of muscle weakness in osteoarthritis is particularly important given our growing understanding of safe and effective methods for increasing strength in elderly persons [7, 8]. A substantial proportion of persons who have radiographic evidence of osteoarthritis of the knee have no joint pain [9]. Because asymptomatic persons with radiographic changes seldom seek medical attention for osteoarthritis, muscle weakness has not been studied previously in this group. Thus, it is not known whether quadriceps weakness precedes or follows joint pain or (if it follows joint pain) whether it is mediated by disuse atrophy or by physiologic mechanisms that may inhibit muscle contraction [10]. To address this issue, we studied the relation among lower-extremity muscle strength, lower-extremity lean tissue mass, and osteoarthritis of the knee in men and women 65 years of age and older. Methods Study Group To obtain a sample of elderly persons living in the community, we conducted brief telephone interviews with residents of households in central Indiana. Potential participants were selected through modified random-digit dialing to increase the sampled proportion of persons 65 years of age and older. Persons were eligible if they met the minimal criteria for participation: They were willing and able to provide informed consent and to undergo the necessary strength assessments and other evaluations. Persons were excluded if they had had amputations of both lower extremities, had undergone total knee arthroplasty, or had recently had a cerebrovascular accident or myocardial infarction. A total of 462 persons (approximately 55% of all who were eligible) agreed to participate and completed the following evaluations. Evaluations Radiography of the Knee Standing anteroposterior and lateral radiographs of both knees of each study participant were obtained, and the severity of osteoarthritis in the tibiofemoral compartment was graded by a musculoskeletal radiologist according to the criteria of Kellgren and Lawrence. Similar criteria, based on the presence of osteophytes and joint space narrowing, were used for the patellofemoral compartment [11]. The radiologist was blinded to the clinical status and characteristics of all patients. A participant had to have a Kellgren and Lawrence grade of 2 or more in either knee to be classified as having osteoarthritis. Knee Pain and Function The Western Ontario and McMaster Universities Arthritis Index was used to evaluate knee pain and function [12]. This index assesses the severity of knee pain during 5 activities or situations (walking on a flat surface, going up or down stairs, at night while in bed, sitting or lying, and standing upright) and the severity of impairment of lower-extremity function during 17 activities. Pain and functional impairment were assessed in each knee separately. Responses to each question about the severity of knee pain and level of impairment were recorded on a categorical scale as none, mild, moderate, severe, or extreme. Each category was assigned a corresponding numeric score from 1 to 5 (5 = extreme). Hence, the range on the pain scale was 5 to 25 and the range on the physical impairment scale was 17 to 85 (85 = greatest functional limitation). For the purposes of analysis, participants who rated the severity of their knee pain as moderate or greater (3) with any of the 5 activities on more than half of the days in the month preceding the evaluation were considered to have knee pain. Thus, pain in the more distant past that had resolved was not included. Participants were also questioned about current and previous regular (5 times per week) or occasional use of over-the-counter and prescription analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) in the past year. Lower-Extremity Muscle Strength The strength of each leg was evaluated by using an isokinetic dynamometer (KIN-COM 500H, Chattecx Corp., Hixson, Tennessee). Peak torque was recorded in both the concentric (contractions during muscle shortening) and eccentric (contractions during muscle lengthening) modes. Participants were allowed several submaximal or maximal practice efforts to familiarize themselves with the operation of the dynamometer. Once formal testing began, the best of three maximal efforts was recorded for flexion and extension at both 60 degrees per second and 120 degrees per second. Aborted efforts were repeated in order to obtain the best possible representation of strength for each participant. Concentric and eccentric testing yielded similar results, but because of greater variability in eccentric testing, only the concentric test results are shown. Lower-Extremity Lean Tissue Mass Total-body dual-energy x-ray absorptiometry was done in all participants by using a Lunar-DPX-L instrument (Lunar Corp., Madison, Wisconsin). Results were analyzed for total and regional body composition, including body fat, mineral, and lean components (lean components were components other than fat or mineral). The right and left lower extremities were analyzed separately. The lower extremity was defined as all tissue below a diagonal line drawn outward and upward from the groin area through the femoral neck. Statistical Analysis Participants were divided into four groups on the basis of presence or absence of radiographic evidence of osteoarthritis of the knee and presence or absence of knee pain, as defined above. Men and women were compared by using the t-test. Comparisons of Arthritis Index pain and functional impairment scores were done by using nonparametric approaches. For analyses of continuous data involving more than two groups of participants (for example, osteoarthritis with or without knee pain), analysis of variance was used to determine whether an overall difference was present. The Fisher protected least-significant-difference procedure was used for pairwise comparisons. Comparisons within participants (for example, comparison of the two legs in a person with unilateral osteoarthritis of the knee) were done by using paired t-tests. Regression models were constructed with the generalized estimating equations approach of Zeger and Liang [13]. This approach inflates the standard errors to adjust for correlations in both independent variables (such as strength) and dependent variables (such as radiographic grade) within participants. Statistically significant differences (P < 0.05) in the above analyses are specifically noted below. Results The characteristics of the 462 men and women in the cohort are shown in Table 1. As expected, men were taller, were heavier, and had greater lower-extremity strength and lean tissue mass in the lower extremities compared with women (P < 0.001 for all comparisons). Table 1. Age, Height, Weight, and Lower-Extremity Strength and Lean Tissue Mass* One hundred forty-five participants (31%; 33% of the women and 30% of the men) had radiographic evidence of osteoarthritis involving the tibiofemoral compartment, the patellofemoral compartment, or both. In 62 participants (43%), the radiographic changes were unilateral. Table 2 shows the association between osteoarthritis and obesity [14-16]. Women in the cohort who had osteoarthritis were approximately 15% heavier than women with normal radiographs and no knee pain. Men with osteoarthritis were also slightly heavier than men without osteoarthritis. Table 2. Body Weight and Summed Arthritis Index Scores for Recent Pain and Function in the Left Knee in Participants with and without Radiographic Evidence of Osteoarthritis* Among those with radiographic evidence of tibiofemoral osteoarthritis, women were slightly more likely than men to report knee pain (P = 0.10; Table 3). Table 3. Radiography and Recent Pain in the Left Knee Table 2 also shows the mean summed and the distribution of scores for left knee pain and functional impairment (data for the right knee were similar). Among men and women with radiographic evidence of osteoarthritis who reported having knee pain, the mean summed pain score for the knee with osteoarthritis was approximately 12 (median score, 2 of 5). In comparison, the mean pain score of participants who reported knee pain but did not have radiographic evidence of osteoarthritis in the painful knee was approximately 10 (median score, 2 of 5)-only slightly lower than the mean pain score of participants with radiographic changes. Consistent with their relatively low pain scores, these community-dwelling participants with osteoarthritis reported moderately low use of NSAIDs (Table 4). Table 4. Participants Reporting Regular Current or Previous Use of Analgesics and Nonsteroidal Anti-inflammatory Drugs Related to the Presence of Radiographic Evidence of Osteoarthritis of the Knee and Recent Knee Pain* Arthritis Index scores for functional impairment paralleled those for pain (Table 2). Participants with osteoarthritis had the greatest functional impairment (P < 0.001 for the comparison with patients who did not have pain or radiographic evidence of osteoarthritis). Functional impairment in participants who had pain but no radiographic evidence of osteoarthrit

Further Evidence Supporting an SEM-Based Criterion for Identifying Meaningful Intra-Individual Changes in Health-Related Quality of Life

This study used the standard error of measurement (SEM) to evaluate intra-individual change on both the Chronic Respiratory Disease Questionnaire (CRQ) and the SF-36. After analyzing the reliability and validity of both instruments at baseline among 471 COPD outpatients, the SEM was compared to established minimal clinically important difference (MCID) standards for three CRQ dimensions. A value of one SEM closely approximated the MCID standards for all CRQ dimensions. This SEM-based criterion was then validated by cross-classifying the change status (improved, stable, or declined) of 393 follow-up outpatients using the one-SEM criterion and the MCID standard. Excellent agreement was achieved for all three CRQ dimensions. Although MCID standards have not been established for the SF-36, the one-SEM criterion was explored in these change scores. Among SF-36 scales demonstrating acceptable reliability and reasonable variance, the percent of individuals within each change category was consistent with those seen in the CRQ dimensions. These results replicate previous findings where a value of one SEM also closely approximated MCIDs for all dimensions of the Chronic Heart Disease Questionnaire among cardiovascular outpatients. The one-SEM criterion should be explored in other health-related quality of life instruments with established MCIDs.

Linking clinical relevance and statistical significance in evaluating intra-individual changes in health-related quality of life.

OBJECTIVE To compare the standard error of measurement (SEM) with established standards for clinically relevant intra-individual change in an evaluation of health-related quality of life. DESIGN Secondary analysis of data from a randomized controlled trial. SUBJECTS Six hundred and five outpatients with a history of cardiac problems attending the general medicine clinics of a major academic medical center. MEASURES Baseline and follow-up interviews included a modified version of the Chronic Heart Failure Questionnaire (CHQ) and the SF-36. The SEM values corresponding to established standards for minimal clinically important differences (MCIDs) on the CHQ were determined. Individual change on the SF-36 was explored using the same SEM criterion. RESULTS One-SEM changes in this population corresponded well to the patient-driven MCID standards on all CHQ dimensions (weighted kappas (0.87; P < 0.001). The distributions of outpatients who improved, remained stable, or declined (defined by the one-SEM criterion) were generally consistent between CHQ dimensions and SF-36 subscales. CONCLUSIONS The use of the SEM to evaluate individual patient change should be explored among other health-related quality of life instruments with established standards for clinically relevant differences. Only then can it be determined whether the one-SEM criterion can be consistently applied as a proxy for clinically meaningful change.

The effect of hip fracture on mortality, hospitalization, and functional status: a prospective study.

OBJECTIVES The purpose of this study was to prospectively assess the independent effect of hip fracture on mortalìty, hospitalization, and functional status. METHODS Among 7527 members of the Longitudinal Study of Aging who were over age 70 at baseline, 368 persons with hip fracture occurring between 1984 and 1991 were identified. Median length of follow-up was 831 days. RESULTS Hip fracture was significantly related to mortality (adjusted hazards ratio [AHR] = 1.83; 95% confidence interval [CI] = 1.55, 2.16) when treated as a time-dependent covariate. This effect was concentrated in the first 6 months postfracture (AHR = 38.93, 95% CI = 29.58, 51.23, vs AHR = 1.17; 95% CI = 0.95, 1.44). Hip fracture significantly increased the likelihood of subsequent hospitalization (adjusted odds ratio = 3.31, 95% CI = 2.64, 4.15) and increased the number of subsequent episodes by 9.4%, the number of hospital days by 21.3%, and total charges by 16.3%. Hip fracture also increased the number of functional status dependencies. CONCLUSIONS The health of older adults deteriorates after hip fracture, and efforts to reduce the incidence of hip fracture could lower subsequent mortality, morbidity, and health services use.

Self-Rated Health: Changes, Trajectories, and Their Antecedents Among African Americans

Objective: Little is known about changes in self-rated health (SRH) among African Americans. Method: We examined SRH changes and trajectories among 998 African Americans 49 to 65 years old who we reinterviewed annually for 4 years, using multinomial logistic regression and mixed effect models. Results: Fifty-five percent had the same SRH at baseline and 4 years later, 25% improved, and 20% declined. Over time, men were more likely to report lower SRH levels, individuals with hypertension were less likely to report lower SRH levels, and those with congestive heart failure at baseline were more likely to report higher SRH levels. Lower SRH trajectory intercepts were observed for those with lower socioeconomic status, poorer health habits, disease history, and worse functional status. Those with better cognitive status had higher SRH trajectory intercepts. Discussion: The decline in SRH levels among 49- to 65-year-old African Americans is comparable to that of Whites.

The Aftermath of Hip Fracture: Discharge Placement, Functional Status Change, and Mortality

The authors prospectively explored the consequences of hip fracture with regard to discharge placement, functional status, and mortality using the Survey on Assets and Health Dynamics Among the Oldest Old (AHEAD). Data from baseline (1993) AHEAD interviews and biennial follow-up interviews were linked to Medicare claims data from 1993-2005. There were 495 postbaseline hip fractures among 5,511 respondents aged >or=69 years. Mean age at hip fracture was 85 years; 73% of fracture patients were white women, 45% had pertrochanteric fractures, and 55% underwent surgical pinning. Most patients (58%) were discharged to a nursing facility, with 14% being discharged to their homes. In-hospital, 6-month, and 1-year mortality were 2.7%, 19%, and 26%, respectively. Declines in functional-status-scale scores ranged from 29% on the fine motor skills scale to 56% on the mobility index. Mean scale score declines were 1.9 for activities of daily living, 1.7 for instrumental activities of daily living, and 2.2 for depressive symptoms; scores on mobility, large muscle, gross motor, and cognitive status scales worsened by 2.3, 1.6, 2.2, and 2.5 points, respectively. Hip fracture characteristics, socioeconomic status, and year of fracture were significantly associated with discharge placement. Sex, age, dementia, and frailty were significantly associated with mortality. This is one of the few studies to prospectively capture these declines in functional status after hip fracture.

Effects of computerized guidelines for managing heart disease in primary care.

BACKGROUND: Electronic information systems have been proposed as one means to reduce medical errors of commission (doing the wrong thing) and omission (not providing indicated care).OBJECTIVE: To assess the effects of computer-based cardiac care suggestions.DESIGN: A randomized, controlled trial targeting primary care physicians and pharmacists.SUBJECTS: A total of 706 outpatients with heart failure and/or ischemic heart disease.INTERVENTIONS: Evidence-based cardiac care suggestions, approved by a panel of local cardiologists and general internists, were displayed to physicians and pharmacists as they cared for enrolled patients.MEASUREMENTS: Adherence with the care suggestions, generic and condition-specific quality of life, acute exacerbations of their cardiac disease, medication compliance, health care costs, satisfaction with care, and physicians’ attitudes toward guidelines.RESULTS: Subjects were followed for 1 year during which they made 3,419 primary care visits and were eligible for 2,609 separate cardiac care suggestions. The intervention had no effect on physicians’ adherence to the care suggestions (23% for intervention patients vs 22% for controls). There were no intervention-control differences in quality of life, medication compliance, health care utilization, costs, or satisfaction with care. Physicians viewed guidelines as providing helpful information but constraining their practice and not helpful in making decisions for individual patients.CONCLUSIONS: Care suggestions generated by a sophisticated electronic medical record system failed to improve adherence to accepted practice guidelines or outcomes for patients with heart disease. Future studies must weigh the benefits and costs of different (and perhaps more Draconian) methods of affecting clinician behavior.

The Effect of Gender and Race on the Measurement Properties of the Ces-d in Older Adults

Having observed a three-fold difference in the prevalence of significant symptoms of depression among four race-gender groups of elderly adults attending an urban primary care practice, we investigated the extent to which these differences might be explained by variability in the measurement properties of the Centers for Epidemiologic Studies depression scale (CES-D). Although the internal consistency of the CES-D was acceptable for all groups, 5% of our patients were excluded for inability to complete the minimum required number of CES-D items, and nearly 40% of patients required response imputation for the allowable one to four items that they could not answer. Imputation was most frequently required for items tapping positive affect. Principal components factor analysis was performed separately for respondents answering all items and for respondents with imputed values. In both analyses we found important race-gender differences in factor structure. Moreover, the factor structure for those with imputed values was markedly different from that of respondents answering all items, including a dissolution of the positive affect dimension. Neither the race-gender differences in factor structure nor the differences among those with and without imputed data were resolved by eliminating respondents with poor education, cognitive impairment, or alcoholism, or by varying the assumptions for data imputation. However, the disparities in factor structure were essentially resolved by eliminating five CES-D items, suggesting the need to modify the CES-D in populations like ours. Although eliminating these five items results in a more pure factor structure, it does not resolve the differences in prevalence of depressive symptoms. These differences may, however, be partially due to differential response tendencies among the race-gender groups.

Health services utilization among the noninstitutionalized elderly.

Data from a two-stage random sample of401 noninstitutionalized elderly individuals residing in 18 census tracts in the south-central part of Metropolitan St. Louis are used to assess the effects of the predisposing, enabling, and need characteristics on ten measures of health services utilization. Hierarchical multiple regression analyses indicate that: (I) Most of the explained variance in health services utilization may be attributed to the need characteristics, suggesting an apparently equitable system; (2) When a comprehensive version of Andersens behavioral model is fielded, from 12 to 35 percent of the variance in health services utilization can be explained; and (3) Nutritional risk is the most important predictor of the total number of physician visits, visits to physicians in the emergency room, and the occurrence of hospital episodes. The implications of these analyses for modeling the health services utilization of elderly as well as for public policy concerning their health care, are discussed.

Personal, Financial, and Structural Barriers to Immunization in Socioeconomically Disadvantaged Urban Children

Objective. To evaluate personal, financial, and structural barriers to vaccination in socioeconomically disadvantaged urban children in the first 2 years of life. Design. Prospective cohort study. Setting. A large municipal teaching hospital in the Midwest. Participants. Healthy term newborns discharged to the care of their mothers. Mothers were interviewed 24 to 72 hours postpartum regarding personal and financial barriers, and 2 years later regarding personal, financial, and structural barriers to care. Main Outcome Measure. Vaccination status at age 2 years. Results. Of 399 children with documented vaccination status, 47% had not received all recommended vaccinations by 2 years of age. After adjusting for mothers age, race, and education, mothers who were unmarried (adjusted odds ratio [AOR] 1.74; 95% confidence interval [CI]: 1.05, 2.90), multiparous (AOR 2.10; 95% CI: 1.26, 3.52), not coresident with the childs grandmother (AOR 1.75; 95% CI: 1.01, 3.03), had not received adequate prenatal care (AOR 1.78; 95% CI: 1.12, 2.84), or lived in poverty (AOR 2.62; 95% CI: 1.44, 4.75) were more likely to have undervaccinated children, as were mothers who perceived less satisfaction with their childs health care (AOR 1.63; 95% CI: 1.01, 2.61), less control over their lives (AOR 2.01; 95% CI: 1.03, 3.94), or more benefit of medical care to prevent vaccine-related diseases (AOR 1.76; 95% CI: 1.25, 2.48). Conclusions. Family environment, a mothers history of prenatal care use, and financial barriers are important factors related to vaccination receipt among socioeconomically disadvantaged children at age 2 years. These factors, however, do not fully explain the variation in vaccination status.