Echographic findings in orbital varices

OBJECTIVE: To ascertain the prevalence of rheumatoid arthritis (RA) in an Italian general population. METHODS: The study was performed in the years 1991-92 in Chiavari, a small town located on the Ligurian coast, and involved 4456 subjects aged 16 years or more from four general practices. The subjects received a postal questionnaire developed to detect patients with current or past inflammatory joint diseases. The age and sex distribution of the sample were similar to those of the Italian population from the 1992 census. Patients reporting a history of joint swelling in at least a pair of symmetrical joints were reviewed by a rheumatologist. The clinical records of non-responders and responders who failed to attend the clinic were also reviewed. RESULTS: 3294 of 4456 (73.9%) subjects answered to the questionnaire. The mean (SD) age of the 3294 responders was 48.3 (19.3) years; 53.7% of them were female. Swelling in at least two symmetrical joints was reported by 230 subjects (7%). Among them, 11 patients fulfilling the 1987 ARA criteria for RA were identified. The prevalence of RA was 0.33% (95% CI 0.13, 0.53) in the general population, 0.13% (95% CI 0, 0.31) in men, and 0.51% (95% CI 0.18, 0.84) in women. CONCLUSIONS: These data are consistent with the results of three earlier studies published in the fifties in the Italian literature and confirm that the prevalence of RA is low in Italy and has remained unchanged in the last 40 years.     

The prevalence and severity of rheumatoid arthritis in Oslo. Results from a county register and a population survey

The objective was (1) to examine the prevalence of rheumatoid arthritis (RA) by a county patient register, (2) to cross-validate the register findings by a postal population survey, and (3) to estimate prevalences of disease subsets according to age, sex, and levels of physical disability. The study was performed within a county setting in the city of Oslo with 356,486 inhabitants between 20 and 79 years of age. Prevalence estimates were calculated from a county patient register comprising 1333 patients with RA and a population survey of 10,000 inhabitants. The overall prevalence of RA between 20 and 79 years was 0.437 (95% CI 0.413, 0.461) after adjusting for the incompleteness of the register by a factor of 1.17. Prevalences exceeding 1.0% was only found among females over 60 years. The prevalence of RA with MHAQ scores > or = 1.5 and > or = 2.0 (range 1-4) was 0.225 (95% CI 0.209, 0.243) and 0.099 (0.088, 0.111) respectively. We conclude that RA is less frequent in the city of Oslo than stated in most of the literature. The prevalence of RA with physical disability levels assumed to be associated with increased mortality is less than half of the overall prevalence of 0.4-0.5%.     

Radiographic outcome of recent-onset rheumatoid arthritis: a 19-year study of radiographic progression

OBJECTIVE: To describe the longitudinal radiographic course of rheumatoid arthritis (RA), and to identify and quantitate predictors of radiographic progression. METHODS: This prospective, longitudinal study of radiographic progression and clinical predictors of RA involved 256 patients with RA who were seen within the first 2 years of disease (mean 0.77 years) and were followed up for up to 19 years. Participants underwent a total of 6,278 clinical assessments (mean 24.5) and 934 paired radiographs (mean 3.1, range 2-6). Clinical assessments at every visit included determination of the erythrocyte sedimentation rate (ESR), grip strength, pain scores, tender joint counts, and anxiety and depression measurements. Regression analyses utilized time-integrated predictors. RESULTS: Overall, radiographic progression rates, as measured by the summary Sharp scores, appeared constant over the course of RA. The strongest correlate of progression was the time-integrated ESR (rho=0.53). This association grew stronger with time. At 0-5 years, 5-10 years, 10-15 years, and 15-20 years, correlations were 0.40, 0.50, 0.65, and 0.74, respectively, and for the period 10-20 years, the correlation was 0.67. In multivariate models, the mean ESR, mean grip strength, rheumatoid factor positivity, and tender joint count were independent predictors of radiographic progression. CONCLUSION: Radiographic damage occurs at a constant rate in RA, and is not greater early in RA or reduced later in the course of the illness. Acute-phase reactants are, by far, the strongest determinants of progression.     

Rheumatoid arthritis and the risk of malignancy

OBJECTIVE: To determine the relative risks of malignancy and of site-specific malignancies in patients with rheumatoid arthritis (RA). METHODS: In a prospective cohort study, 862 patients with RA (96% white) were enrolled from 1966 to 1974 and were followed up for up to 35 years (mean 17.4 years) at the University of Saskatchewan Rheumatic Disease Unit. All diagnoses of cancer were cross-referenced with the Provincial Cancer Registry. Expected cancer incidence rates were determined based on province of Saskatchewan population statistics matched to each study patient for age, sex, and calendar year. Standardized incidence ratios (SIRs) of the observed-to-expected cancer incidence and 95% confidence intervals (95% CI) were then calculated. RESULTS: A total of 136 cases of cancer were observed compared with 168 expected (SIR 0.80, P = 0.011 [95% CI 0.67-0.95]). The relative risk of colorectal malignancy was significantly reduced in the RA study population (SIR 0.52, P = 0.037 [95% CI 0.25-0.96]). A significant excess of leukemia was found (SIR 2.47, P = 0.026 [95% CI 1.12-4.69]), whereas the incidence rates for Hodgkin's disease and non-Hodgkin's lymphoma and all other site-specific malignancies were not found to be significantly different from general population rates. CONCLUSION: In our cohort of RA patients, colorectal cancer was detected in only half the expected number of patients. This risk reduction may be related to long-term nonsteroidal antiinflammatory drug (NSAID) use in RA, as has been suggested in several other studies of long-term NSAID use. An increased risk of leukemia was confirmed. This may be due to the persistent immune stimulation associated with RA itself, since other potential explanatory factors for increased leukemia were not apparent. Despite the excess of hemopoietic malignancy and despite treatment of RA with potentially oncogenic agents, the overall risk of malignancy was reduced in this RA cohort.     

Validation of rheumatoid arthritis improvement criteria that include simplified joint counts

OBJECTIVE: To study the validity of response criteria for rheumatoid arthritis (RA) that included 28-joint counts instead of more comprehensive joint counts. METHODS: In a double-blind, placebo-controlled trial of 105 patients treated with methotrexate, sulfasalazine, or both, response was evaluated at week 52. Both European League Against Rheumatism and American College of Rheumatology definitions of response, with comprehensive as well as simplified joint counts, were calculated. We studied the differences between the criteria with and without simplified joint counts, the discriminating capacity between treatment groups, and the association with change in functional capacity and joint damage. RESULTS: Response criteria that included 28-joint counts classified patients' responses more conservatively. No differences between treatment groups were found with either set of response criteria. The association with change in functional capacity was significant in all cases. All response criteria were significantly associated with radiographic progression of RA. CONCLUSION: Improvement criteria that include 28-joint counts are as valid as the original improvement criteria that included more comprehensive joint counts.     

Oral staphylococcus in older subjects with rheumatoid arthritis

OBJECTIVE: To determine if Staphylococcus aureus and Staphylococcus epidermidis, etiologic bacterial agents to late prosthetic joint infections (LPJI), are more prevalent in the oral flora of older individuals with rheumatoid arthritis (RA) than in an age and gender-matched nonarthritic control population (NA). DESIGN: Cultures were obtained from the nares, oropharynx, saliva, tongue, and gingival crevice, and the results were compared between older patients with RA and controls. SETTING: University of Michigan Medical Center, Ann Arbor, VA Medical Center, and University of Michigan School of Dentistry. PARTICIPANTS: A total of 111 community-dwelling subjects with a diagnosis of RA and 83 gender-matched control subjects. MEASUREMENTS: Colistin nalidixic acid agar plates with 5% sheep's blood were inoculated and incubated. Isolates were speciated using the API Staph Trac micro method and catalase and coagulase tests. MAIN RESULTS: Individuals with RA had a higher prevalence of S. aureus isolated from the oral cavity. However, only the oropharynx and tongue revealed higher rates; all other sites were insignificant. The presence of oral S. aureus was associated with xerostomia. Staphylococcus epidermidis was not detected from any of the oral sites sampled. Sixty-two percent (10/16) of the S. aureus isolates from the RA subjects were resistant to penicillin and ampicillin, whereas none were resistant to a cephalosporin. CONCLUSIONS: These findings suggest that rheumatoid arthritis may be a risk factor for LPJI in older prosthetic joint patients undergoing invasive dental procedure in the posterior oral cavity. This increased risk is caused, in part, by a higher prevalence of S. aureus in the posterior oral cavity. The prevalence and the antibiotic resistance of S. aureus must be considered when determining the need for chemoprophylaxis.     

Epidemiological and clinical aspects relating to the variability of rheumatoid arthritis

OBJECTIVE: To review epidemiological studies dealing with the temporal and geographic variability in the occurrence of rheumatoid arthritis (RA) and clinical studies that address the variability of severity and manifestations among populations. METHODS: An extensive search of the literature, including a Medline search, was completed. Studies addressing the origin, history, and trends in the occurrence of RA were reviewed first. Next, studies of the prevalence and incidence of RA in different populations were reviewed, and occurrence rates compared. Standardization was attempted by tabulating adult prevalence rates of studies using equivalent sets of criteria. Studies comparing RA patients from two populations were sought next. Finally, studies dealing with explanations of the presumed variability were reviewed. RESULTS: Temporal variability is indicated by paleopathological evidence that RA has existed in the New World since 4000 BC, whereas there is no evidence that it occurred in Europe before the 17th century, or in Africa before the 20th century. Epidemiological studies show a possible trend of decreasing incidence of RA in the United States and Western Europe, whereas reports from Africa note a rising incidence. In white populations of Europe and America, prevalence is approximately 1%, and incidence is 0.03%. Significantly higher rates are found in some North American Indians, and significantly lower rates in some Asian and African populations, even when the different population structures are taken into account. In the latter populations, different patterns of occurrence from those observed in whites emerge, such as greater female preponderance and a much younger peak age at onset. Direct standardized comparisons of two diverse populations of RA patients showed some differences in expression, severity, or manifestations of RA between populations. CONCLUSION: The occurrence and manifestations of RA are temporally and geographically variable.     

The correlation of indium-111 joint scans with clinical synovitis in rheumatoid arthritis

OBJECTIVE: An inflammatory compartment radionuclide such as Indium-111 chloride (111InCl3) may offer advantages over bone seeking radionuclides in the assessment of active rheumatoid synovitis. As an iron analog, 111InCl3 binds iron complexing proteins including transferrin. Active rheumatoid synovitis is a transferrin receptor rich compartment, reflecting profound cellular activation and proliferation. We investigated 111InCl3 scanning for the detection of active rheumatoid arthritis (RA). METHODS: Nine patients satisfying ACR criteria for definite or probable RA were scanned twice at a 28-day interval. Patients were undergoing multiple medication changes with resultant fluctuating disease activity. Blinded readings were performed by an experienced nuclear medicine physician and correlated with simultaneous clinical examinations by a single rheumatologist. Sixteen assessed joint areas/patient and a total of 144 joint areas were available for analysis. RESULTS: Scintigraphy correlated with swollen and tender joint scores at both timepoints. Specificity was highest with stringent scoring. Sensitivity was lowest for small joints with lower 111InCl3 uptake relative to background. A receiver operator curve (ROC), generated to analyze the diagnostic value of varying 111InCl3 scan stringency, demonstrated utilization of the most accurate portion of the ROC curve by the reader. CONCLUSION: 111InCl3 joint scintigraphy correlates with clinically detectable rheumatoid synovitis, supporting the hypothesis that transferrin receptor levels reflect rheumatoid disease activity.     

Diagnosis and course of early-onset arthritis: results of a special early arthritis clinic compared to routine patient care

OBJECTIVE: Early arthritis patients referred to an Early Arthritis Clinic (EAC) (n = 233) were compared to 241 patients from the routine out-patient clinic with respect to lag time between the onset of symptoms and the visit to the rheumatologist, clinical presentation and the consistency of the diagnosis after 1 yr. RESULTS: The reduction in median lag time for the EAC patients was at least 3 months. An insidious onset of symptoms was found more often in the rheumatoid arthritis (RA) patients in the routine clinic. In 70% of all cases, a diagnosis could be made after 2 weeks and, if the clinical diagnosis was definite RA, this hardly changed during the following year. Early erosions were seen in 25% of RA patients and were associated with a positive rheumatoid factor (OR 2.08, 95% CI 0.95 4.59). CONCLUSION: An early diagnosis of RA at the EAC is possible and reliable; the high frequency of erosions illustrates the need for early treatment.     

Inhibition in a microgravity environment of the recovery of Escherichia coli cells damaged by heavy ion beams during the NASDA ISS phase I program of NASA Shuttle/Mir mission no. 6

OBJECTIVE: To explore whether there are different disease patterns of rheumatoid arthritis (RA) in women and men. METHODS: We studied 55 male case patients and 110 female control patients who developed RA between 1970 and 1985 and who resided and received medical care in Olmsted County, Minnesota, for at least 10 years after the diagnosis of RA. Case and control patients were matched for the date of first diagnosis. The pattern and extent of joint involvement, the frequency of joint surgeries, and the presence and type of extraarticular manifestations were determined by retrospective chart review. RESULTS: Incidence rates in women were variable and age dependent, whereas the risk in men older than 36 years was constant over their lifetime. Erosive disease was more frequent in men than in women (72% versus 55%, respectively; P < 0.05) and tended to occur earlier (47% versus 31% for erosive disease within the first 4 years of RA). Although male sex was correlated with a higher risk of bony erosions and an accelerated course of RA, structural consequences of joint destruction were more pronounced in women. Joint surgery was performed more frequently in women (50%) than in men (27%) (P = 0.01). In particular, the frequencies of arthroplasties and arthrodeses of hand and foot joints were different (34 procedures in women versus 1 procedure in men; P < 0.001). Sex influenced the risk as well as the pattern of organ involvement in RA. Nodules and rheumatoid lung disease were typical manifestations in men (P = 0.001 and P < 0.001, respectively), whereas women typically developed sicca syndrome (P = 0.05). Despite differences in disease aggressiveness and disease pattern, there was little difference in the medical therapy in the men compared with the women. CONCLUSION: RA is a heterogeneous disease with variations in phenotype. Sex-associated factors influence disease severity as well as disease pattern. Because sex-related effects influence treatment goals, treatment responses, and side effects, they should be considered in clinical study design and analysis as well as in the treatment decisions for individual patients with RA.     

The five mysteries of the mind, and their consequences

OBJECTIVE: Using the European Community (EC) criteria for classification Vitali et al. Arthritis Rheum 1993;36:340 7, we report the prevalence estimates of Sjogren's syndrome (SS) from a general population and present the first population data to assess the impact of the syndrome. METHODS: A cross-sectional population-based survey performed on 1000 adults, aged 18-75 yr, randomly selected from a population register. Responders to the initial postal phase were invited for an interview. The five criteria measured at interview were: (1) the reporting of subjective oral symptoms lasting for > 3 months; (2) the reporting of subjective ocular symptoms lasting for >3 months; (3) Schirmer-I test; (4) unstimulated salivary flow; (5) autoantibodies [Ro (SS-A), La (SS-B), rheumatoid factor (RF), antinuclear antibodies (ANA)]. SS was diagnosed if at least four of these five criteria were positive. The MOS Short-form 36 (SF-36), General Health Questionnaire (GHQ) and the Health and Fatigue Questionnaire (HFQ) were completed by subjects after the interview, and scores were compared between those with and without a diagnosis of SS. RESULTS: A total of 341 subjects completed both the postal questionnaire and home visit. A diagnosis of SS could be given to 13 subjects. After adjusting for the presence of possible bias due to non-response, our best estimate of the prevalence of SS in the study population was 33 per 1000 subjects (95% CI 22 44). The prevalence of the disorder was higher in females (38; 95% CI 27-52) and for those subjects aged > or = 55 yr (46; 95% CI 34-61). Those subjects diagnosed positively were more impaired for each of the eight dimensions of the SF-36 than those without a diagnosis, and also suffered from higher levels of depression and fatigue. CONCLUSIONS: SS affects approximately 3-4% of adults and in the general population appears to be associated with a clinically significant impairment of a subject's health and well-being.     

Clinical course and remission rate in patients with early rheumatoid arthritis: relationship to outcome after 5 years

OBJECTIVE: To investigate the clinical course in early rheumatoid arthritis (RA) patients followed prospectively, to relate course to outcome after 5 yr, and to try to identify prognostic features. METHODS: A total of 183 patients with definite RA and a mean disease duration of 11 months were included. Of these, 75% were rheumatoid factor (RF) positive; 85% carried the shared epitope, 32% on both alleles. Most patients were assessed every 6 months. Disability was evaluated with the Health Assessment Questionnaire (HAQ) and radiographic findings according to Larsen. Remission was defined in two ways: with the American Rheumatism Association (ARA) criteria and as 'no arthritis at least at one follow-up visit'. RESULTS: Twenty per cent achieved ARA-defined remission periods of at least 6 months duration; 21 were spontaneous and 18 drug induced. Average length of remission was 20.5 months. The remission periods constituted 7% of follow-up for all patients. Another 36% achieved remission according to the second definition. All 56% were considered to have a relapsing-remitting disease pattern, in contrast to the remaining 44% with a persistent disease pattern. More patients with persistent disease were treated with disease-modifying anti-rheumatic drugs (DMARDs) and had also received a larger number of different drugs. Outcome after 5 yr regarding disability, joint inflammation and joint damage was worse for patients with persistent disease. Neither ARA-defined remission nor disease pattern could be accurately predicted. CONCLUSIONS: Long-term ARA-defined remission was rare, constituting 7% of follow-up for the entire cohort. For those 20% achieving remission, this period represented 34% of their follow-up. A total of 56% had a relapsing-remitting disease pattern and 44% had a persistent disease pattern. This classification had prognostic implications with persistency being a bad prognostic sign.     

Dynamic exercise therapy in rheumatoid arthritis: a systematic review

The aim of this systematic review was to determine the effectiveness of dynamic exercise therapy in improving joint mobility, muscle strength, aerobic capacity and daily functioning in patients with rheumatoid arthritis (RA). In addition, possible unwanted effects such as an increase in pain, disease activity and radiological progression were studied. A computer-aided search of the MEDLINE, Embase and SCISEARCH databases was performed to identify controlled trials on the effect of exercise therapy. Randomized trials were selected on the effect of dynamic exercise therapy in RA patients with an exercise programme fulfilling the following criteria: (a) intensity level such that heart rates exceeded 60% of maximal heart rate during at least 20 min; (b) exercise frequency > or = 2 a week; and (c) duration of intervention > or = 6 weeks. Two blinded reviewers independently selected eligible studies, rated the methodological quality and extracted data. Six out of 30 identified controlled trials met the inclusion criteria. Four of the six included studies fulfilled > or = 7/10 methodological criteria. Because of heterogeneity in outcome measures, data could not be pooled. The results suggest that dynamic exercise therapy is effective in increasing aerobic capacity and muscle strength. No detrimental effects on disease activity and pain were observed. The effects of dynamic exercise therapy on functional ability and radiological progression are unclear. It is concluded that dynamic exercise therapy has a positive effect on physical capacity. Research on the long-term effect of dynamic exercise therapy on radiological progression and functional ability is needed.     

Blood transfusion, smoking, and obesity as risk factors for the development of rheumatoid arthritis: results from a primary care-based incident case-control study in Norfolk, England

OBJECTIVE: To examine a range of demographic, social, and clinical risk factors for the development of rheumatoid arthritis (RA). METHODS: Population-based case-control study in Norfolk, England, involving adult patients, ages 18-70, with an inflammatory polyarthritis of <12 months' duration who were recruited from the Norfolk Arthritis Register. Controls, matched for sex and date of birth, were selected from the primary care register of the Norwich Health Authority. Both cases and controls completed identical self-administered questionnaires. Matched analysis of the 165 case-control sets was conducted for the whole group and for the subset in which the cases satisfied the 1987 American College of Rheumatology criteria for RA. RESULTS: The controls were of higher socioeconomic status than the cases. This was probably due to response bias. Having a body mass index > or =30 was associated with an adjusted odds ratio (OR) of 3.74 for developing RA (95% confidence interval [95% CI] 1.14-12.27). RA was also associated with a history of blood transfusion (OR 4.83, 95% CI 1.29-18.07). Even after correcting for social class, a history of having ever smoked was associated with a higher risk of developing RA (OR 1.66, 95% CI 0.95-3.06). There was no difference between cases and controls in previous exposure to childhood infections, certain surgical procedures, or reproductive history variables. CONCLUSION: RA has a number of potential environmental triggers, including smoking, obesity, and blood transfusion.     

Dose escalation with repeated intrathecal injections of 131I-labelled MAbs for the treatment of central nervous system malignancies

OBJECTIVE: The 1987 American Rheumatism Association (ARA) criteria for rheumatoid arthritis (RA) were developed to discriminate between patients with established RA and those with another rheumatological disorder. Their ability to determine which patients presenting with early synovitis have "true" RA is not known. We evaluated whether the 1987 ARA classification criteria for RA in patients newly presenting with inflammatory polyarthritis (IP) predict persistent, disabling, or erosive arthritis. METHODS: We studied 486 patients with early IP referred to the Norfolk Arthritis Register. The 1987 ARA criteria were applied at baseline, and assessed for their ability to identify (1) patients referred to hospital for whom the diagnosis of RA was recorded by the hospital physician; (2) patients at 3 years with (a) persistent synovitis; (b) moderate or greater disability; and (c) erosions. RESULTS: At baseline, 323 (67%) patients satisfied the ARA criteria in the classification tree format. Exactly 50% of those referred to hospital were given a diagnosis of RA. By 3 years, 76% of the 486 patients had persistent disease, 36% had a Health Assessment Questionnaire score > or = 1, and 40% had erosions. The sensitivity of the criteria was good, ranging from 77 to 87% depending on the outcome. The specificities were poor, and thus the overall discriminatory ability showed little improvement over random probability. CONCLUSION:. Among patients newly presenting with IP, the 1987 ARA criteria for RA had a low ability to discriminate between patients who developed persistent, disabling, or erosive disease and those who did not. Alternative criteria are required for studies investigating early RA.     

Influence of non-inherited maternal HLA-DR antigens on susceptibility to rheumatoid arthritis

OBJECTIVE: It has recently been observed that non-inherited maternal DR4 antigens (NIMAs) of DR4 negative rheumatoid arthritis (RA) patients were increased compared with non-inherited paternal DR4 antigens (NIPAs). The aim of this study was to determine the prevalence of non-inherited DR4 antigens and DRB1 alleles in parents of RA patients. METHODS: HLA-DR serology and DRB1 typing was performed in 97 RA patients and their parents. NIMA and NIPA frequencies were compared, stratified according to the presence of DR4 and/or the shared epitope (SE). RESULTS: In DR4 negative patients, NIMA DR4 was increased compared with NIPA DR4 (OR 3.10, 95% CI 0.76, 12.70). When combined with results from a previous study this increase was significant (OR 3.65, 95% CI 1.29, 10.31). The NIMA effect of SE positive DR4 subtypes in this study (OR 4.73, 95% CI 0.94, 23.8) was stronger than the NIMA effect of combined SE positive DRB1 alleles (OR 2.19 95% CI 0.36, 13.22). CONCLUSIONS: The association between non-inherited maternal HLA-DR4 alleles and the susceptibility to RA was observed in two independent populations.     

Methotrexate therapy in rheumatoid arthritis: a life table review of 587 patients treated in community practice

To determine whether methotrexate (MTX) maintains its effectiveness in rheumatoid arthritis (RA) in the setting of community based private rheumatology practice we used life table analysis to review the combined experience of a group of these practices. Of 587 patients with RA who started to take MTX, total termination rate at 70 months was 24.4% with most terminations prompted by drug toxicity. Older age (greater than 65 years) was associated with higher rates of toxicity. Treatment termination rates varied substantially between rheumatologists. We conclude that MTX therapy for RA is well tolerated and maintains effectiveness for at least 70 months.     

Rheumatic diseases in China: ILAR-China study comparing the prevalence of rheumatic symptoms in northern and southern rural populations

OBJECTIVE: To determine the prevalence of rheumatic diseases in Han Chinese in north and south China. METHODS: Samples of 4192 adults in the Beijing (north) and 5057 in the Shantou (south) areas, based on village administration registers, were studied. The same questionnaire was administered by doctors who then examined those with rheumatic symptoms. One observer (QYZ) took part in both studies. RESULTS: The prevalence of definite rheumatoid arthritis (RA) was 0.34% (95% CI; 0.20-0.51) in the north and 0.32% (0.16-0.47) in the south. Ankylosing spondylitis (AS) was noted in 0.26% of both samples (95% CI; 0.11-0.42 north and 0.14-0.40 south). Only 3 cases of systemic lupus erythematosus (SLE) in the north and one in the south were identified. General rheumatic pain was reported more frequently in the north. Lumbar problems were recorded on examination 5 times more frequently in the north than in the south [men, 25%:5.3%; women 38%:6.5%] and knee problems 10 times more frequently [men, 24%:1.8%; women, 36%:3.4%] in the north. The difference was greatest in the 55 to 64 year age group. CONCLUSION: The prevalence of RA was similar to that in other rural populations and Japan, but only half that reported from other industrialized communities. The prevalence of AS was similar to that in most Caucasian populations. SLE was too infrequent to establish a prevalence with confidence, but did not differ from that in other populations. A study is planned in the south to assess the contribution of interobserver error and/or differences in cultural response to the north/south differences observed in the prevalence of general rheumatic symptoms and back pain.     

Decreasing incidence and prevalence of rheumatoid arthritis in Pima Indians over a twenty-five-year period

OBJECTIVE: To evaluate temporal trends in the incidence of rheumatoid arthritis (RA). METHODS: Incident cases of RA were identified among a population-based cohort of Pima Indians in Arizona over the period 1965-1990. RESULTS: Among 2,894 subjects, 78 incident cases of RA were identified. The age-adjusted incidence declined by 55% in men (Ptrend = 0.225), and by 57% in women (Ptrend = 0.017) after controlling for oral contraceptive or estrogen use and for pregnancy experience. During the same period, age-adjusted prevalence rates of active RA decreased by 29% in men (Ptrend = 0.63) and by 40% in women (Ptrend = 0.02). Fewer than 17% of subjects with known RA were taking slow-acting antirheumatic drugs (SAARDs) in 1990. CONCLUSION: The decrease in incidence and prevalence of RA in this population over such a short period implicates the involvement of an environmental factor(s), other than exogenous estrogens, in the pathogenesis of the disease. However, the possibility that the observed decrease might be explained by an increased use of SAARDs in subjects with RA cannot be excluded.     

Factors associated with the development of vasculitis in rheumatoid arthritis: results of a case-control study

OBJECTIVE: To investigate those characteristics of patients with rheumatoid arthritis (RA) that are associated with the development of rheumatoid vasculitis (RV). METHODS: Demographic and clinical data of 69 patients who had been diagnosed as having RV were compared with those of 138 contemporaneous control patients with RA who were not suspected to have vasculitis. Vasculitis was confirmed histologically in 96% of the subjects with RV. RESULTS: Variables associated with the development of RV were: 1) male gender, presence of increased serum concentrations of rheumatoid factor, joint erosions, subcutaneous nodules, number of disease modifying antirheumatic drugs previously prescribed, treatment (ever) with D-penicillamine or azathioprine; 2) presence of nail fold lesions and any other extrarticular feature one year before the time of diagnosis of RV; 3) treatment with corticosteroids at the time of diagnosis of RV. CONCLUSIONS: The development of RV is associated with male gender, extra-articular features, and a severe course of RA as indicated by the presence of joint destruction and need for intensive treatment with antirheumatic drugs. The strongest association was found with the presence of increased concentrations of rheumatoid factor.