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Objective: To develop and evaluate a prototype measure (OA-DISABILITY-CAT) for osteoarthritis research using item response theory (IRT) and computer-adaptive test (CAT) methodologies., Study Design and Setting: We constructed an item bank consisting of 33 activities commonly affected by lower extremity (LE) osteoarthritis. A sample of 323 adults with LE osteoarthritis reported their degree of limitation in performing everyday activities, and completed the Health Assessment Questionnaire-II (HAQ-II). We used confirmatory factor analyses to assess scale unidimensionality and IRT methods to calibrate the items and examine the fit of the data. Using CAT simulation analyses, we examined the performance of OA-DISABILITY-CATs of different lengths compared with the full-item bank and the HAQ-II., Results: One distinct disability domain was identified. The 10-item OA-DISABILITY-CAT demonstrated a high degree of accuracy compared with the full-item bank (r=0.99). The item bank and the HAQ-II scales covered a similar estimated scoring range. In terms of reliability, 95% of OA-DISABILITY reliability estimates were over 0.83 vs. 0.60 for the HAQ-II. Except at the highest scores, the 10-item OA-DISABILITY-CAT demonstrated superior precision to the HAQ-II., Conclusion: The prototype OA-DISABILITY-CAT demonstrated promising measurement properties compared with the HAQ-II, and is recommended for use in LE osteoarthritis research.

Background: Several nutrients are known to affect bone mineral density (BMD). However, these nutrients occur together in foods and dietary patterns, and the overall effects of dietary choices are not well understood., Objective: We evaluated associations between dietary patterns and BMD in older adults., Design: Of the original Framingham Heart Study subjects, 907 aged 69-93 y completed food-frequency questionnaires as part of an osteoporosis study. We defined dietary patterns by cluster analysis. BMD was measured at the proximal right femur (femoral neck, trochanter, Ward's area) with a dual-photon absorptiometer and at the 33% radial shaft with a single-photon absorptiometer. We regressed BMD measures onto the cluster variable, adjusting for potential confounders., Results: Six dietary patterns were identified, with relatively greater proportions of intake from meat, dairy, and bread; meat and sweet baked products; sweet baked products; alcohol; candy; and fruit, vegetables, and cereal. After adjustment for multiple comparisons, men in the last group had significantly (P = 0.05) greater BMD than did 2-4 other groups at the hip sites and the candy group at the radius. Men in the candy group had significantly (P < 0.05) lower BMD than did those in the fruit, vegetables, and cereal group for 3 of the 4 sites. Women in the candy group had significantly (P < 0.01) lower BMD than did all but one other group at the radius., Conclusions: Dietary pattern is associated with BMD. High fruit and vegetable intake appears to be protective in men. High candy consumption was associated with low BMD in both men and women.

Although less common than in women, osteoporosis in men is a prevalent worldwide problem with important socioeconomic implications. Our understanding of this condition in men is growing, but there remains a great deal more to be determined. Definitions for osteoporosis in men are needed. Cost-effective guidelines on who should be investigated and treated, and how, are clearly necessary. The role of bone mineral densitometry in diagnosis and treatment decisions needs to be clarified. The efficacy of drug therapies for osteoporosis in men requires greater attention. Currently, a large multicenter study is underway in the United States and should provide much needed insight into the epidemiology of osteoporosis in men.

Background: Dermatomyositis and polymyositis are associated with cancer, but previous nationwide studies have not had sufficient cases to test the association between myositis and specific cancer types. Our aim was to investigate the risk of specific cancer types in individuals with dermatomyositis and polymyositis., Methods: We did a pooled analysis of published national data from Sweden, Denmark, and Finland. All patients with dermatomyositis and polymyositis (> or =15 years old) were identified by discharge diagnosis from the Swedish National Board of Health (1964-83), Danish Hospital Discharge Registry (1977-89), and Finnish National Board of Health (1969-85). Personal details were matched to national cancer registries, to identify all cases of cancer up to 1987 in Sweden, 1995 in Denmark, and 1997 in Finland, and to national death registries for the same periods. We calculated standardised incidence ratios (SIR) for individual cancer sites for dermatomyositis and polymyositis separately, using national cancer rates by country, sex, age, and date., Findings: We identified 618 cases of dermatomyositis, of whom 198 had cancer. 115 of the 198 developed cancer after diagnosis of dermatomyositis. This disease was strongly associated with malignant disease (SIR 3.0, 95% CI 2.5-3.6), particularly ovarian (10.5, 6.1-18.1), lung (5.9, 3.7-9.2), pancreatic (3.8, 1.6-9.0), stomach (3.5, 1.7-7.3), and colorectal (2.5, 1.4-4.4) cancers, and non-Hodgkin lymphoma (3.6, 1.2-11.1). 137 of the 914 cases of polymyositis had cancer, which developed after diagnosis of polymyositis in 95. Polymyositis was associated with a raised risk of non-Hodgkin lymphoma (3.7, 1.7-8.2), and lung (2.8, 1.8-4.4) and bladder cancers (2.4, 1.3-4.7). In both dermatomyositis and polymyositis, risk of malignant disease was highest at time of myositis diagnosis., Interpretation: Our results provide evidence that dermatomyositis is strongly associated with a wide range of cancers. The overall risk of malignant disease is also modestly increased among patients with polymyositis, with an excess for some cancers.

Several definitions have been used to characterize radiographic worsening of knee osteoarthritis in longitudinal studies, yet a valid definition with maximal power to detect differences between groups is not known. We used serial radiographs from the Framingham Osteoarthritis Study to compare five dichotomous definitions according to construct validity (strength of association) and discriminant power (power to reject null hypotheses of no difference) for 1) known risk factors for knee osteoarthritis, and 2) development of new knee pain. For risk factors: definitions that included scores for osteophytes (bone spurs) showed good construct validity and discriminant power; a definition using the Kellgren and Lawrence grade of overall knee osteoarthritis was conservative with good construct validity but low discriminant power; a definition based solely on ordinal assessment of joint space narrowing had weak construct validity and low discriminant power. All definitions had comparably strong associations with the development of new knee pain. Similar associations with new knee pain were found when the analysis was confined to either knees with no osteoarthritis at baseline or knees with prevalent osteoarthritis, with increased standard errors for prevalent osteoarthritis. Use of any of these definitions, other than joint space narrowing alone, would permit detection of associations with most known risk factors. Definitions incorporating both osteophytes and joint space narrowing offer the most precise estimation of the association of risk factors with disease worsening.

This study describes the distribution and determinants of plasma 25-hydroxyvitamin D [25(OH)D] concentrations and risk factors for low 25(OH)D (< or = 37.5 nmol/L) in 290 men and 469 women aged 67-95 y who were in the Framingham Heart Study cohort. Mean (+/-SD) 25(OH)D concentrations were 82 +/- 29 nmol/L in men and 71 +/- 29 nmol/L in women. 25(OH)D was low in 6.2% of men and 14.5% of women. 25(OH)D concentrations were strongly associated with season of examination, inversely associated with time spent indoors and body mass index, and positively associated with dietary vitamin D intake. In women, concentrations were also inversely associated with age and positively associated with supplemental vitamin D intake and residence for > or = 3 mo/y in Florida, California, or Arizona, and in men were positively associated with serum creatinine concentrations. Similar amounts of variance in 25(OH)D concentrations were explained by vitamin D intake and sunlight exposure, the former being more important in women and the latter in men. None of the known or suspected determinants of vitamin D status could explain the lower 25(OH)D concentrations in women, but the sex difference was not seen for individuals examined during the winter. Results from this population-based sample of elderly individuals suggest that inadequate vitamin D status is an important public health problem, which could be readily addressed by adequate vitamin D intake or sunlight exposure.

Osteoarthritis is the most common form of arthritis. It increases in prevalence with age. About 5% of the US population is affected with hip or knee osteoarthritis; 9.5% of adults aged > 62 y have knee osteoarthritis. Because of its frequency and associated pain and disability, osteoarthritis accounts for much of the disability in lower extremities in the elderly. More than 70% of total hip and knee replacements are for osteoarthritis. Because osteoarthritis is so common, the modification of factors that increase osteoarthritis risk could prevent substantial pain and disability in the elderly and the use of costly health care services. Overweight persons are at high risk of osteoarthritis in the knee and probably also in the hips and hands. The mechanism by which overweight causes osteoarthritis is poorly understood; a contribution from both local increased force across the joint and systemic factors is likely. Better evidence is needed on the effects of weight loss, but preliminary studies suggest that weight loss can both prevent the onset of symptomatic disease and alleviate symptoms when present.

Because data archives contain patient-based rather than study-based data, they can address meta-analytic questions on uncommon outcomes and on predefined patient subsets, questions that are difficult to address using the traditional meta-analytic approach based on grouped data. We report the tasks involved in establishing the first data archive of rheumatoid arthritis trials. In general, problems stem from the heterogeneity of trials in the archive and we suggest some solutions. In the initial phases, difficulties include recruitment and incomplete participation of trial investigators, whereas later on, other issues arise, such as quality control, coping with different dataset designs, and incomplete documentation. Other issues include heterogeneous measures, missing variables, and comparing data across different visit intervals and trial lengths. Suggested solutions include requesting trial data in predefined archive-wide structures and asking for all possible documentation for each dataset. Data cleaning is necessary, as is rescaling of variables or developing unit-free outcomes, and estimating data for missing variables. Archive design should allow for referencing a patient's data among various datasets. Although one goal is to reduce the quantity of data in the archive while retaining information content, data from early stages of archive building must be accessible for developing new analysis datasets. Documentation of archive building and software choices are discussed. Our experience suggests data archiving for meta-analysis is time consuming and expensive, yet it provides a useful method for analyzing data from multiple trials.

The natural history of knee, hip, and hand osteoarthritis (OA) is variable. Pathologic changes of OA generally remain stable or worsen, although some patients with hip osteoarthritis may actually sustain reconstitution of joint space. Even with stable pathology, patients often experience symptomatic improvement. Risk factors for OA progression include elderly age, coexistent crystal disease, concurrent OA in multiple joints (generalized disease), neuropathy, and, for knees, obesity.

With the proliferation of meta-analyses in the medical literature have come conflicting studies. In addition, observance of guidelines for the performance of meta-analyses has been spotty. Bias may explain conflicting studies and differentiate carefully performed meta-analyses from others. Meta-analysts may fail to anticipate biases which threaten their study's validity. The three stages at which bias can be injected into a meta-analysis are finding studies, selection of the identified studies for the meta-analysis and extraction of data from the selected studies. This manuscript reviews specific types of bias which are common at each of these stages.

Educational attainment has been negatively associated with the prevalence, morbidity and mortality of many diseases. With knee osteoarthritis as an example, we used NHANES I data to examine whether the cross-sectional association between formal education and disease is due to known risk factors, and also whether educational attainment is more strongly associated with self-reported symptoms or with radiographic change. We found univariate associations between osteoarthritis and low levels of education. For radiographic knee osteoarthritis in women, and in both sexes combined, this relationship was explained by controlling for known risk factors, which included age, knee injury, race, obesity, and occupation. However, even after adjusting for these major risk factors and the presence of radiographic changes, reporting of knee pain and arthritis at any site remained significantly associated with low educational attainment, especially for those with less than or equal to 8 years of education.

In summary, the relationship between risk factors and OA may differ across joints. For knees, obesity and knee injury either due to acute events or to repetitive impact loading may be the most important preventable causes of disease. Hand OA is probably also caused by repetitive use, but its association with other risk factors is unknown. Hip OA is probably different from OA in other joints, in that many cases are due to congenital and developmental abnormalities. Current inquiry focuses on generalized OA and its predictors. Future studies will look at the long-term course of OA and will focus especially on as-yet unidentified risk factors.

Studies investigating steroid dose and avascular necrosis of bone (AVN) have found either a weak association or none at all. This quantitative review of published studies has evaluated the effects of steroid dose and bolus steroids on the risk of AVN. 22 papers with sufficient information for analysis were identified. The mean steroid dose for the cohort was plotted against the percentage in whom AVN developed. Total dose was divided into non-bolus (oral) and bolus dose, and doses 1, 3, 6, and 12 months after beginning steroids were tested separately for their association with AVN risk. There was a strong correlation between daily total dose and AVN rate (r = 0.61-0.80). Oral dose was strongly correlated with AVN rate (r = 0.70-0.86), but bolus dose was not associated with AVN risk. This strong association between AVN and steroid dose contrasts with the weak relations found in case-control studies from individual centres in which cases and controls received similar steroid regimens and therefore did not differ greatly in steroid dose. The method of deriving a single exposure level per study and comparing the amount of exposure across studies may be useful in assessing whether a drug's toxicity is dose dependent.