Rheumatoid arthritis in Hiroshima and Nagasaki, Japan. Prevalence, incidence, and clinical characteristics

Prevalence of patients with rheumatoid arthritis and age-stratified trends in clinical characteristics and treatment, based on the National Database of Health Insurance Claims and Specific Health Checkups of Japan

AIM

To estimate the prevalence and age-stratified treatment trends and clinical characteristics of rheumatoid arthritis (RA) in Japan.

METHOD

Using 7 RA definitions, the prevalence of RA in those aged ≥16 years was estimated using the National Database of Health Insurance Claims and Specific Health Checkups of Japan in the fiscal year 2017. We analyzed age-stratified trends in characteristics and treatments.

RESULTS

Of 1 116 122 patients aged ≥16 years with at least 1 RA-related International Classification of Diseases-10 code, 825.7 thousand patients (women, 76.3%) were assessed as having RA with an estimated prevalence of 0.65%. The highest age-stratified prevalence was 1.63% in patients aged 70-79 years. Overall, 60.8% and 7.0% of patients with RA were aged ≥65 years and ≥85 years, respectively. Methotrexate use was most frequent in patients aged 50-59 years (73.0%) and least frequent in patients aged ≥85 years (38.2%). Biologic disease-modifying antirheumatic drugs use was 50.9% in patients aged 16-19 years and decreased to 13.7% in those aged ≥85 years. Preference for the use of tumor necrosis factor inhibitors versus abatacept decreased from 24.0:1 to 1.7:1 in patients aged 16-19 years and ≥85 years, respectively. The prevalence of cardiovascular disease was 3.5% in patients aged 60-69 years and 12.1% in those aged ≥85 years. Overall RA-related orthopedic surgeries were most prevalent in patients aged 70-79 years.

CONCLUSION

The estimated prevalence of patients with RA in Japan was 0.65%. Age-stratified treatment trends and clinical characteristics have been described in a super-aged society for the first time.

Analysing homœopathic prescribing using the READ Classification and information technology

Some practical results of computerized data collection are presented. Use was made of the ABIES relational database which supports a medical nomenclature called the READ classification. The Glasgow, Royal London and Bristol Homœopathic Hospitals have been working together on this project.

For practical purposes the main focus in this study has been rheumatoid arthritis. The broader objective, however, is to show the potential of systematic computerized data collection for homœopathy in general.

Clinical aspects of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease of unknown etiology affecting both articular tissues and extraarticular organs. The disease is often progressive and results in pain, stiffness, and swelling of joints culminating in significant morbidity and increased mortality. This chapter discusses the epidemiology, possible etiology, clinical manifestations, diagnostic approach and treatment options of RA.

Mortality of rheumatoid arthritis in Japan: a longitudinal cohort study

OBJECTIVE

To determine the mortality risk of Japanese patients with rheumatoid arthritis, taking into account lifestyle and physical factors, including comorbidity.

METHODS

91 individuals with rheumatoid arthritis were identified during screening a cohort of 16 119 Japanese atomic bomb survivors in the period 1958 to 1966. These individuals and the remainder of the cohort were followed for mortality until 1999. Mortality risk of the rheumatoid patients was estimated by the Cox proportional hazards model. In addition to age and sex, lifestyle and physical factors such as smoking status, alcohol consumption, blood pressure, and comorbidity were included as adjustment factors for the analysis of total mortality and for analysis of mortality from each cause of death.

RESULTS

83 of the rheumatoid patients (91.2%) and 8527 of the non-rheumatoid controls (52.9%) died during mean follow up periods of 17.8 and 28.0 years, respectively. The age and sex adjusted hazard ratio for mortality in the rheumatoid patients was 1.60 (95% confidence interval, 1.29 to 1.99), p < 0.001. Multiple adjustments, including for lifestyle and physical factors, resulted in a similar mortality hazard ratio of 1.57 (1.25 to 1.94), p < 0.001. Although mortality risk tended to be higher in male than in female rheumatoid patients, the difference was not significant. Pneumonia, tuberculosis, and liver disease were significantly increased as causes of death in rheumatoid patients.

CONCLUSIONS

Rheumatoid arthritis is an independent risk factor for mortality. Infectious events are associated with increased mortality in rheumatoid arthritis.

National databases and rheumatology research I: longitudinal databases in Scandinavia

Nationwide population-based longitudinal databases provide excellent resources for medical research in Scandinavia. These include the Population Registry, the Cancer Registry, the Cause of Death Registry, the Hospital Discharge Registry, and other registers, and are linkable to each other by the personal identification code. The registers have long historical backgrounds, and are regulated strictly by law. This article describes features of the national databases and provides some examples of rheumatology research that use these databases.

Changes in the incidence and prevalence of rheumatoid arthritis in Kamitonda, Wakayama, Japan, 1965-1996

OBJECTIVE

To evaluate secular trends in the incidence and prevalence of rheumatoid arthritis (RA) in Japan.

METHODS

The incidence and prevalence of RA were determined in a longitudinal population based study in the Kamitonda district, Wakayama, Japan, from 1965 to 1996.

RESULTS

In the study area consisting of about 3000 inhabitants, 16 incident cases, satisfying definite RA by the Rome criteria were detected during the study period. The age and sex adjusted incidence in both men and women combined and the age adjusted incidence in women significantly decreased (p<0.025 and p<0. 01, respectively). The age and sex adjusted prevalence in all inhabitants tended to decrease (p<0.1), and the age adjusted prevalence in women significantly declined (p<0.025). In men, however, neither incidence nor prevalence showed significant change.

CONCLUSIONS

The decline of incidence and prevalence of female RA may be reducible to some environmental changes preferentially occurring more obviously in Japanese women than in men. Because the use of oral contraceptives has been extremely low in Japan, the decline should be explained by other factors.

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.

Epidemiology and estimated population burden of selected autoimmune diseases in the United States

Autoimmune diseases cause significant and chronic morbidity and disability. The actual number of persons in the United States that are affected by autoimmune diseases and the resultant magnitude of their impact on the public's health are limited to a few specific diseases. In order to understand the clinical, public health and economic importance of these diseases it is necessary to have estimates of incidence and prevalence rates in the population. In this analysis, we estimate the number of persons affected by 24 autoimmune diseases in the United States by applying mean weighted prevalence and incidence rates obtained from published articles to U. S. Census data. The study was restricted to 24 autoimmune predefined diseases for which there was direct or indirect evidence for autoimmune pathogenesis. Subsequently, we used computerized search software and ancestry searching (bibliographies) to conduct a comprehensive search of articles published from 1965 to the present. Eligible studies included those which adhered to standard disease definitions and which included population-based estimates of incidence or prevalence rates. Mean weighted incidence and prevalence rates were calculated from eligible published studies with greater weight proportionately given to larger studies. The mean rates were then applied to the U.S. Census population figures to estimate the number of persons currently afflicted with each disease and the number of new cases occurring each year in the United States. Only U.S. and European studies were used to estimate prevalence and incidence rates when there were at least six eligible studies available for a disease. When there were fewer than six studies, all available studies were included, regardless of country of origin. The number of eligible incidence and prevalence studies found in the literature varied considerably between the 24 autoimmune diseases selected. The largest number of eligible prevalence studies were conducted on multiple sclerosis (MS), rheumatoid arthritis, and systemic lupus erythematosus (SLE) (>/=23), followed by insulin-dependent diabetes (IDDM), myasthenia gravis, primary biliary cirrhosis, and scleroderma (>/=7). There were only one to four eligible studies done on 11 other diseases, and no prevalence studies on 6 diseases. Incidence studies were less frequent but the largest number of studies were conducted on IDDM (n = 37) and MS (n = 28), followed by Graves' disease/hyperthyroidism, glomerulonephritis, primary biliary cirrhosis, rheumatic fever, rheumatoid arthritis, scleroderma, and SLE (>/=9). On the other 11 diseases, there were one to six eligible studies, and no studies on 5 diseases. There were no eligible incidence or prevalence studies on Goodpasture's syndrome, idiopathic thrombocytopenia purpura, or relapsing polychondritis. Overall we estimate that 8,511,845 persons in the United States or approximately 1 in 31 Americans are currently afflicted with one of these autoimmune diseases. The diseases with the highest prevalence rates were Graves'/hyperthyroidism, IDDM, pernicious anemia, rheumatoid arthritis, thyroiditis, and vitiligo, comprising an estimated 7,939, 280 people or 93% of the total number estimated. Glomerulonephritis, MS, and SLE added an estimated 323,232 people. The prevalence of the other diseases reviewed were rare, less than 5.14/100,000. Most diseases were more common in women. From the incidence data we estimate that 237,203 Americans will develop an autoimmune disease in 1996 and that approximately 1,186,015 new cases of these autoimmune diseases occur in the United States every 5 years. Women were at 2.7 times greater risk than men to acquire an autoimmune disease. After reviewing the medical literature for incidence and prevalence rates of 24 autoimmune diseases, we conclude that many autoimmune diseases are infrequently studied by epidemiologists. As a result the total burden of disease may be an underestimate. (ABSTRACT TRUNCATED)

Perioperative management of the rheumatoid patient

Rheumatoid arthritis is a systemic disease that can affect multiple organ systems of the body. It is a symmetrical polyarthropathy which leads to destruction of cartilage and bone. Before undertaking surgery on the rheumatoid patient, several issues need to be addressed. A thorough evaluation by a multidisciplinary team is essential to decrease any operative risks involved. This is a review of some of the systemic manifestations of rheumatoid arthritis with an emphasis on anesthesiology, and radiological consultation, and perioperative surgical management of rheumatoid drug therapy.

Late effects of radiation on the human immune system: an overview of immune response among the atomic-bomb survivors

The studies of the late effects of atomic-bomb (A-bomb) radiation on the immune system were started about 20 years after the bombings in 1945. The most remarkable late effects of radiation are the functional and quantitative abnormalities of T and B cells in survivors exposed to high doses (> or = 1.0 Gy). Abnormalities of T-cell immunity include (1) a decreased proportion of CD3+ T cells in peripheral blood lymphocytes, particularly the proportion of CD4+ CD45RA+ naive T cells (study period 1987-91); (2) an increased frequency of CD4- and CD8- (double negative) alpha beta + T cells (1987-91); and (3) functional defects in T-cell responses to mitogens and alloantigens (1974-85). B-cell abnormalities include: (1) a significant increase in the proportion of B cells among peripheral lymphocytes (1987-91); (2) an increase in serum immunoglobulin A levels in females and immunoglobulin M and the incidence of rheumatoid factor in both sexes (1987-89); and (3) an increased level of anti-Epstein-Barr virus antibody titer (1987-90). In contrast, suggestive (0.05 < p < 0.1) or not significant (p > 0.1) dose effects were observed for the number and function of natural killer cells (1983-91), and benign monoclonal gammopathy (1979-87). In addition, studies initiated sooner after the bombing such as the incidence of autoimmune diseases (1958-87), systemic bacterial infections (1954-67), and granulocyte functions (1947-79) also show little dose-effects. Thus, A-bomb radiation induced the alteration of the balance/interaction between the T- and B-cell subsets--specifically, a decrease in the T-cell population and an increase in the B-cell population in the periphery.

Rheumatoid arthritis in the northeastern area of the People's Republic of China and western Japan

The clinical features of 134 consecutive hospitalized patients with rheumatoid arthritis in the northeastern area of the People's Republic of China and 251 consecutive hospitalized patients from western Japan were compared. A total of 91.8% of the Chinese patients were of Han nationality, while all of the patients from Japan were Japanese. The patients in the People's Republic of China showed more inflammatory articular disease and more frequent subcutaneous nodules than did the Japanese patients in the presence of a less elevated ESR value and less radiographic joint destruction. The clinical features of the patients of Han nationality and the Japanese did not change even after adjusting the patients' age and disease duration. The reasons for the contradictory features in the Chinese patients still remain to be clarified. This study is hopefully a first step in promoting more precise studies on rheumatoid arthritis in the People's Republic of China.

Low incidence of rheumatoid arthritis in France

The incidence of rheumatoid arthritis (RA) was estimated in the Lorraine district, eastern France, over the period 1986-1989. Cases were identified from in- and outpatients at the district Rheumatology Hospital Centre, private rheumatologists, general practitioners and by regional media announcements. Supplementary cases resident in the area were sought by extending the procedure to adjacent districts. The population count was obtained from the national Census. An overall age-adjusted incidence rate of 8.8/100,000 was found using the 1987 ACR criteria (12.7/100,000 in females, 4.7/100,000 in males; sex ratio = 2.65) and 9.5/100,000 using the 1958 ARA criteria (definite and classic RA). These rates were compared, using the same standard population, with the age-adjusted incidence rates in other incidence studies mainly conducted in Caucasian populations. The RA incidence rates appeared lower in France than in any other country in Europe, USA and Japan.

Rheumatoid arthritis in women. Incidence rates in group health cooperative, Seattle, Washington, 1987-1989

As part of a prospective case-control study of newly diagnosed rheumatoid arthritis (RA) in women, we identified all cases of probable, definite, or classic RA diagnosed in 1987-1989 in 18-64-year-old women who were members of a health maintenance organization based in the Seattle, Washington area. Using both the 1958 and the 1987 American Rheumatism Association criteria for the diagnosis of RA and enrollment data from the health maintenance organization, we calculated the incidence by age and diagnostic class. Rates of RA incidence in women increased steadily with age. The incidence of probable, definite, or classic RA ranged from 13.1 per 100,000 person-years at risk for 18-29-year-old women to 82.1 per 100,000 person-years for 60-64-year-old women. The overall incidence rate, age-adjusted to the 1980 US female population, was 27.9/100,000 person-years. The overall incidence rate for definite/classic RA, age-adjusted to the 1980 US female population, was 23.9 per 100,000 person-years. When compared with adjusted rates of incidence of definite RA in Rochester, Minnesota, in 1950-1974, the incidence rates we found were 44.7% lower. Methodologic differences, changes in diagnostic criteria, and a declining incidence of RA among women over time may all be partial explanations for these results. The possible effects of reproductive factors, including oral contraceptives use, are discussed.

Changes in the incidence and prevalence of rheumatoid arthritis in England and Wales, 1970-1982

Data from the Second and Third National Studies of Morbidity Statistics from General Practice, conducted from 1970 to 1972 and 1981 to 1982, respectively, by the General Practice Research Unit of the Royal College of General Practitioners, were analyzed to estimate morbidity rates of RA and examine changes in these rates over time. The age-adjusted annual incidence of RA in females fell from 3.3 to 2.6 cases per 1,000 person-years from 1970 to 1972 and 1980 to 1981; there was no change observed in males. Over the same time interval, there was a rise in age-adjusted period prevalence of RA in both sexes from 6.4 to 7.5 per 1,000 and 2.8 to 3.5 per 1,000 in females and males, respectively. These data, which should be interpreted with caution, confirm a decline in incidence of RA in females and demonstrate an increase in prevalence of RA in both sexes over the past decade.

Are there secular trends in the occurrence and severity of rheumatoid arthritis?

There are considerable research and health service benefits in understanding current trends in a disease as common and as severe as rheumatoid arthritis. Unfortunately in the absence of both a high and constant case fatality rate and a population based morbidity registration system, there is no direct means of assessing changes in incidence in contrast, for example, to the situation with cancer. All the available data are inadequate and subject to considerable bias. It is of note however that all the available data are relatively consistent in pointing to a recent reduction in incidence over the last two decades coupled with a decrease in case severity. The immediate problem remains therefore to set up a true population based recording system which will permit the identification of trends both of incidence and severity. It should not be necessary for this to be established nationwide and a study area within a country could be chosen providing its population was representative and of sufficient size. For the latter a minimum seize of 500,000 persons would be needed.

Rheumatoid arthritis in a Chippewa Band. I. Pilot screening study of disease prevalence

The Mille Lacs Band of Chippewa Indians in central Minnesota was screened for rheumatoid arthritis, with a 77% completion rate of the reservation census. Rheumatoid arthritis was found in marked excess, namely 6.8% of those evaluated or, minimally, 5.3% of the total band if all persons had been evaluated with no additional cases identified. This relatively closed population thus provides an opportunity to assess genetic and environmental factors of significance in this disease.

Developments in epidemiological studies on rheumatoid arthritis

The present state of epidemiological knowledge concerning rheumatoid arthritis is summarized. The potential for further epidemiological approaches to rheumatoid arthritis is indicated and priorities listed for the future directions of such studies.

Heberden Oration, 1969. Rheumatoid arthritis--nature or nurture?

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