ABSTRACT
Background: Primary care is one of the key environments in which to target public health and sedentary behaviours are increasing being linked to several adverse health outcomes. The aim of this study was to determine the prevalence and correlates of sedentary behaviour in an adult primary care population. Methods: The International Physical Activity Questionnaire was used to collect data on the weekday sitting of participants. Stratified random sampling based on urban/rural location and deprivation was used to identify three primary care centres from which the sample was drawn. Results: Data were collected from 885 participants (96.7% response rate) of whom 64% (n = 565) were female and 36% (n = 320) were male. The mean age was 42 (SD 14.2). Overall 48% (n = 418) of participants sat for >4 h daily with a median sitting time of 240 min (IQR 150-480). Attendance at the urban non-deprived primary care centre (B = 0.237, P < 0.001), male gender (B = 0.284, P < 0.001), overweight/obesity (B = 0.081, P = 0.048) and having a disability or injury limiting physical activity (B = 0.093, P = 0.028) were associated with higher sitting times. Conclusion: This study established the factors that influence sedentary behaviours in the primary care population which can help inform the development and targeting of promotional strategies.
Subject(s)
Exercise/psychology , Primary Health Care/statistics & numerical data , Rural Population/statistics & numerical data , Sedentary Behavior , Urban Population/statistics & numerical data , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Ireland/epidemiology , Male , Middle Aged , Prevalence , Surveys and Questionnaires , Young AdultABSTRACT
OBJECTIVES: To investigate the physical activity of adults attending primary care services in the Republic of Ireland and to determine whether the location (urban/rural) and deprivation of the primary care centre influenced physical activity. STUDY DESIGN: Cross sectional study. METHODS: Stratified random sampling based on urban/rural location and deprivation was used to identify three primary care centres from a list of established primary care teams in the Leinster region. The International Physical Activity Questionnaire (IPAQ) was used to collate data on physical activity category (low/moderate/high), total weekly activity (MET-minutes/week) and weekly walking (MET-minutes/week) of participants. RESULTS: Data from 885 participants with a median age of 39 years (IQR 31-53) were analysed. There were significant differences in physical activity between the primary care areas (P < 0.001). Rural mixed deprivation participants were the least active with almost 60% of this group (59.4%, n = 177) classified as inactive (535 median MET-minutes/week, IQR 132-1197). Urban deprived participants were the most active (low active 37.6%, n = 111, 975 median MET-minutes/week, IQR 445-1933). Upon adjustment for multiple factors, rural participants (OR = 2.81, 95% CI 1.97-4.01), urban non-deprived participants (OR = 1.61, 95% CI 1.08-2.39), females (OR = 1.66, 95% CI 1.23-2.23) and older adults (OR = 1.01, 95% CI 1.00-1.02) were more likely to be categorised as low active. Overall 47.2% (n = 418) of all participants were classified within the low physical activity category. CONCLUSIONS: Significant disparities exist in the physical activity levels of primary care populations. This has important implications for the funding and planning of physical activity interventions.
Subject(s)
Exercise , Primary Health Care , Rural Population , Urban Population , Adult , Cross-Sectional Studies , Female , Health Status Disparities , Humans , Ireland , Male , Middle Aged , Rural Population/statistics & numerical data , Socioeconomic Factors , Urban Population/statistics & numerical data , Walking/statistics & numerical dataABSTRACT
OBJECTIVES: To examine the role of gender, age and coping in psychological adjustment of patients with early inflammatory polyarthritis (IP). METHODS: One hundred and twelve patients with IP of up to 18 months' duration from the Norfolk Arthritis Register completed questionnaires measuring coping, anxiety, disability and pain. RESULTS: Thirty-six per cent of the patients were at risk of depressive symptoms. Women had significantly higher levels of depression and anxiety than men. Regression analyses showed that pain and (low) illness acceptance predicted levels of depression. Younger age, wishful thinking and covering up predicted anxiety levels. CONCLUSIONS: The study found higher levels of depression and anxiety for women than men with early IP. Psychological distress was predicted by younger age, specific coping strategies and high levels of pain.
Subject(s)
Adaptation, Psychological , Arthritis, Rheumatoid/psychology , Adolescent , Adult , Age Factors , Aged , Anxiety/etiology , Arthritis, Rheumatoid/rehabilitation , Depression/etiology , Female , Humans , Male , Middle Aged , Psychiatric Status Rating Scales , Registries , Sex FactorsABSTRACT
OBJECTIVE: To estimate the health service, non-health service and total costs and predictors of costs in individuals with early inflammatory polyarthritis (IP). METHODS: We conducted a prospective longitudinal study over a 6-month period. The participants were a random sample of 133 individuals who had enrolled with the community-based Norfolk Arthritis Register (NOAR) database between 1994 and 1999. The main outcome measures were the mean (per person) 6-month health service cost, non-health-service cost and total cost associated with IP. RESULTS: One hundred and fifteen of the 133 individuals who were recruited into the study completed 6 months of follow-up. The mean 6-month total cost was estimated to be 2800 pounds sterling per person, of which 14% was health service costs and the remainder non-health-service costs. Higher total costs were associated with lower health status and rheumatoid factor positivity. CONCLUSIONS: Early IP has a considerable impact on both the health-care system and, more importantly, society. Non-health-service costs (i.e. costs incurred by the individual with the disease, their family and friends) account for a substantial proportion (86%) of the total costs associated with early IP.
Subject(s)
Arthritis/economics , Cost of Illness , Health Care Costs , Adolescent , Adult , Community Health Services , Databases, Factual , Female , Humans , Male , Middle Aged , Prospective Studies , Random Allocation , United KingdomABSTRACT
BACKGROUND: Treatment, and therefore outcome, of rheumatoid arthritis (RA) will improve in the next few years. However, improvement in outcome can only be judged against the probability of certain outcomes with current conventional treatment. AIM: To document the five year outcome of RA in the late 1990s. SETTING: Norfolk Arthritis Register (NOAR). DESIGN: Longitudinal observational cohort study. METHODS: 318 patients with recent onset inflammatory polyarthritis recruited by NOAR in 1990-91 completed five years of follow up. Four groups were assessed: the whole cohort, all those referred to hospital, those who satisfied criteria for RA at baseline, and those referred to hospital who satisfied criteria for RA at baseline. Outcome was assessed with a visual analogue scale for pain, the Health Assessment Questionnaire (HAQ), and the Short Form-36 (SF-36). RESULTS: Of the RA hospital attenders, 50% had a visual analogue scale pain score of 5 cm or less and an HAQ score of 1.125 or less. SF-36 scores were reduced in all domains. Results are presented as cumulative percentages. CONCLUSIONS: These results can be used for comparison and to set targets for improvement.
Subject(s)
Arthritis, Rheumatoid/therapy , Benchmarking , Adult , Aged , Female , Health Status , Humans , Longitudinal Studies , Male , Middle Aged , Pain Measurement , Quality of Life , Referral and Consultation , Treatment OutcomeABSTRACT
OBJECTIVE: To determine the effect of treatment with disease-modifying antirheumatic drugs (DMARDs) and/or steroids on 5-year disability outcome in patients with inflammatory polyarthritis. METHODS: Three hundred eighty-four patients registered by the Norfolk Arthritis Register (a primary care-based observational cohort) were followed up for 5 years. Treatment details and Health Assessment Questionnaire (HAQ) scores were recorded annually. Logistic regression was used to model differences in baseline factors associated with the start of DMARDs and/or steroids within 12 months of baseline. Based on this model, each subject was given a probability of starting treatment ("propensity score"). A second model compared the odds of disability (HAQ score > or =1.00) in treated and untreated patients, adjusting for differences in disease severity using the propensity score. RESULTS: Unadjusted analysis suggested that patients who received treatment had an increased odds of a worse outcome compared with those who did not receive treatment. When adjusted for differences in disease severity, using the propensity score, early treatment (within 6 months of symptom onset) was associated with a similar odds of disability at 5 years compared with those not treated (odds ratio 0.71; 95% confidence interval 0.34, 1.44). In contrast, starting treatment later (> or =6 months) was associated with a 2-fold increased odds of having a HAQ score > or =1.00 at 5 years. CONCLUSION: The propensity score was a useful method of adjusting for "confounding by indication" in observational studies. Furthermore, this study showed that early treatment with DMARDs/steroids (within 6 months of symptom onset) reduced the odds of disability 5 years later to a level comparable with that of patients judged clinically as not requiring treatment.
Subject(s)
Antirheumatic Agents/therapeutic use , Arthritis/drug therapy , Arthritis/rehabilitation , Adult , Aged , Arthritis/immunology , Disability Evaluation , Female , Health Status Indicators , Humans , Logistic Models , Male , Middle Aged , Patient Dropouts , Phenylketonurias , Prospective Studies , Registries , Treatment OutcomeABSTRACT
OBJECTIVE: To compare the accuracy of simple demographic and clinical variables recorded at baseline with those recorded after one year followup, in predicting self-reported functional disability recorded 5 years after initial assessment in patients with early inflammatory polyarthritis (IP). METHODS: We followed annually for 5 years 528 patients registered by the Norfolk Arthritis Register (a primary care based cohort of patients with early IP) using the Health Assessment Questionnaire (HAQ). Backward stepwise logistic regression was used to determine the clinical and demographic variables, collected at either baseline or first followup, that were associated with disability (HAQ > or = 1.00/> or =1.50) at 5 years. RESULTS: At the 5th anniversary assessment, the prevalence of moderate disability (HAQ > or = 1.00) was 47%. Twenty-nine percent reported more severe disability (HAQ > or = 1.50). Variables recorded at first anniversary assessment were better able to predict patients at risk of developing a poor outcome than baseline variables. Multivariate methods identified age at symptom onset, HAQ score, presence of nodules, and a statistically derived factor describing joint tenderness recorded at first year as important predictors of both moderate disability (HAQ > or =1.00) and a higher level of disability (HAQ > or = 1.50). When tested in an independent validation sample, the accuracy of the models generated from data recorded at the first year was 76% (HAQ > or = 1.00) and 83% (HAQ > or = 1.50). CONCLUSION: It was possible to predict disability at 5 years with high accuracy using simple clinical variables and demographic data collected 4 or 5 years previously. First year HAQ score was the strongest predictor of future disability. HAQ score at 5 years could be predicted more accurately using data collected at first anniversary visit than using data recorded at baseline.
Subject(s)
Arthritis, Rheumatoid/pathology , Disability Evaluation , Adult , Age Factors , Aged , Arthritis, Rheumatoid/physiopathology , Female , Follow-Up Studies , Humans , Joints/pathology , Joints/physiopathology , Male , Middle Aged , Models, Biological , Predictive Value of Tests , Prognosis , Prospective Studies , Reproducibility of Results , Rheumatoid Nodule/pathology , Severity of Illness Index , Surveys and QuestionnairesABSTRACT
OBJECTIVE: To estimate the secondary health service care and second line drug costs (including drug monitoring costs) for a cohort of people with early inflammatory polyarthritis (IP) and the subgroup classified as having rheumatoid arthritis (RA) recruited to a population based register. METHODS: The study population consisted of 344 people with IP who had enrolled on the Norfolk Arthritis Register (NOAR) in 1990-91, an average of 24 weeks after onset of their symptoms. Utilizing resource use data from NOAR, augmented by unit cost data from other sources, the average (per person) and cumulative secondary care and second line drug costs were estimated for Years 1, 2, 3, 4, and 5 following registration with NOAR. RESULTS: The total secondary health service care and second line drug costs were 472,125 (338,704 for RA subgroup) (1990-91 prices) over the 5 year study period, with inpatient stays, outpatient visits, and second line drugs accounting for 58, 9, and 33%, respectively. Nineteen percent of the study population neither visited hospital nor were prescribed second line drugs. CONCLUSION: Overall, inpatient stay costs represented the largest proportion of secondary health service care and second line drug costs, making 21% of the total study cohort responsible for 80% of the total 5 year costs incurred.
Subject(s)
Arthritis/economics , Direct Service Costs/statistics & numerical data , Drug Costs/statistics & numerical data , Adolescent , Adult , Ambulatory Care/economics , Arthritis/therapy , Cohort Studies , Costs and Cost Analysis/statistics & numerical data , Female , Hospitalization/economics , Humans , Male , Middle Aged , Regression Analysis , Toxicity Tests/economics , United KingdomABSTRACT
OBJECTIVE: To establish the prevalence of work disability and predictors of change in employment status in patients with early rheumatoid arthritis (RA). SETTING: The Norfolk Arthritis Register (NOAR), a primary-care based inception cohort of patients with recent-onset inflammatory arthritis. METHODS: Two cohorts of patients notified to NOAR, who satisfied the 1987 ACR criteria for RA at the time of notification (baseline) and who were economically active at the time of RA symptom onset, were identified. Cohort 1 consisted of 160 patients with an onset of RA between 1989 and 1992, and was followed for a mean of 8.6 yr from symptom onset. For 110 of these cases, a control group, matched for age, gender and employment status at baseline, was identified from the local population. Their employment histories were compared in 1995. Cohort 2 consisted of 134 patients with an onset of RA between 1994 and 1997, and was followed for a mean of 4.1 yr from symptom onset. RESULTS: One-third of RA cohort 1 had stopped working on the grounds of ill health by 1995. The baseline health assessment questionnaire (HAQ) score was the most important predictor of work disability. These patients were 32 times more likely to stop work on health grounds than the matched controls. The rates for work disability for the RA cases 1, 2, 5 and 10 yr after symptom onset were 14, 26, 33 and 39% respectively. For cohort 2, the rates for work disability 1 and 2 yr from onset were 23 and 33% respectively. CONCLUSION: Work disability is an important outcome in RA patients of working age. Many people stop working very early in the disease process, often before they are referred to hospital or started on disease-modifying anti-rheumatic drugs. Although the peak rates for work disability are in the early years, people with RA continue to leave the work force several years after onset. Thus, the recent move to earlier, more aggressive treatment has had no effect on the rates of work disability.
Subject(s)
Arthritis, Rheumatoid , Disabled Persons , Employment , Adult , Age of Onset , Aged , Antirheumatic Agents/therapeutic use , Case-Control Studies , Cohort Studies , Female , Humans , Male , Middle Aged , Prognosis , Workers' Compensation/statistics & numerical dataABSTRACT
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.
Subject(s)
Arthritis, Rheumatoid/classification , Arthritis/classification , Adolescent , Adult , Aged , Aged, 80 and over , Arthritis/diagnosis , Arthritis/epidemiology , Arthritis, Rheumatoid/diagnosis , Cohort Studies , England/epidemiology , Female , Follow-Up Studies , Humans , Male , Middle Aged , PrognosisABSTRACT
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.
Subject(s)
Arthritis, Rheumatoid/etiology , Obesity/complications , Obesity/epidemiology , Smoking/adverse effects , Transfusion Reaction , Adult , Aged , Arthritis, Rheumatoid/epidemiology , Arthritis, Rheumatoid/psychology , England/epidemiology , Female , Humans , Immunization/adverse effects , Life Style , Male , Middle Aged , Risk Factors , Socioeconomic FactorsABSTRACT
OBJECTIVE: To determine whether the presence of psoriasis influences the presentation and early outcome of disease in a primary case based inception cohort of patients with early inflammatory polyarthritis. METHODS: In total, 966 patients with early inflammatory polyarthritis referred to the Norfolk Arthritis Register were studied. The clinical and demographic variables of patients with and without psoriasis were compared. RESULTS: Fifty-one patients (5.3%) had psoriasis on examination. Compared to other patients with inflammatory polyarthritis, those with psoriasis were significantly more likely to be male (49 vs 34%) and less likely to be seropositive for rheumatoid factor (RF) (13 vs 31%). The pattern of joint involvement was similar, as was the outcome at one year. Fewer patients with psoriasis developed radiological erosions (22 vs 39%). Multivariate analysis suggested that this was due to RF acting as a confounder. CONCLUSION: Among patients with early inflammatory polyarthritis there are few strong differences between patients with and without psoriasis, some of which may be accounted for by the absence of RF.
Subject(s)
Arthritis, Psoriatic/epidemiology , Arthritis, Rheumatoid/epidemiology , Psoriasis/complications , Adolescent , Adult , Aged , Aged, 80 and over , Arthritis, Psoriatic/blood , Arthritis, Psoriatic/etiology , Arthritis, Rheumatoid/blood , Arthritis, Rheumatoid/etiology , Cohort Studies , Female , Humans , Male , Middle Aged , Registries , Rheumatoid Factor/blood , Sex Characteristics , Treatment Outcome , United Kingdom/epidemiologyABSTRACT
Musculoskeletal symptoms may occur following various types of immunization, and it has also been suggested that, like infection, immunization may act as a trigger for rheumatoid arthritis (RA). A total of 48 of 898 (5.3%) patients with early inflammatory polyarthritis (IP) referred to the Norfolk Arthritis Register reported an immunization in the 6 weeks prior to symptom onset. There were no important clinical or demographic differences between the 48 immunized patients and 185 consecutive patients who did not report prior immunization. In addition, the frequencies of HLA-DRB1*01. *04 and the shared epitope in 33 of the immunized patients were similar to those in the 185 non-immunized patients and to those in 136 healthy controls. Further results from a case-control study suggest that the rate of immunization is higher amongst cases (5.5%) than age- and sex-matched controls (2.8%). In a small number of susceptible individuals, immunization may thus act as a trigger for RA.
Subject(s)
Arthritis/etiology , Immunization/adverse effects , Adolescent , Adult , Aged , Aged, 80 and over , Alleles , Arthritis, Rheumatoid/immunology , Case-Control Studies , Female , HLA-DR Antigens/blood , HLA-DR Antigens/genetics , HLA-DRB1 Chains , Humans , Inflammation/etiology , Middle AgedABSTRACT
This paper reports the frequency and predictors of remission (no arthritis on examination and no treatment with second-line drugs or steroids within the previous 3 months) in 358 patients with early inflammatory polyarthritis (IP) referred to the Norfolk Arthritis Register. Two years after referral, 91 patients (25%) were in remission, 32 of whom had also been in remission at 1 yr. Remission rates were twice as high in patients with undifferentiated inflammatory polyarthritis at baseline as in those who satisfied criteria for rheumatoid arthritis. To identify predictors of remission, a logistic regression model was developed on a random two-thirds of the patients and validated on the remaining one-third. Remission at 2 yr was associated with male gender and fewer than six tender joints at baseline. However, even the best-fitting model was not sensitive enough to be useful clinically. Thus, amongst patients with early IP in the community, remission rates at 2 yr are low. Further, it was impossible, using simple clinical measures, to predict those patients whose arthritis would resolve.
Subject(s)
Arthritis/complications , Inflammation/complications , Cohort Studies , Humans , Multivariate Analysis , Remission, SpontaneousABSTRACT
OBJECTIVE: To predict which patients with early inflammatory polyarthritis presenting to primary care will be functionally disabled one year after presentation, in order to inform treatment and referral decisions. METHODS: The study population consisted of 381 patients notified to the Norfolk Arthritis Register, a primary care based inception cohort of patients with inflammatory polyarthritis. Patients were regarded as functionally disabled if they had a Health Assessment Questionnaire (HAQ) score of one or more. Clinical, laboratory, and demographic variables easily measured at baseline were analyzed for their ability to predict future disability. Recursive partitioning was used to create a simple decision tree to predict those patients who would be disabled at one year. A logistic regression model was generated on a sample of 277 patients and tested on an independent sample of 104 patients. This was compared with other models, one of which consisted of the 1987 ARA criteria. RESULTS: 112 (29%) patients had a HAQ score of at least 1 at one year. The strongest predictors of future disability were a high baseline HAQ, large joint involvement, female sex, and longer disease duration. The decision tree predicted disability accurately in 67% of patients. CONCLUSION: It is possible to predict functional outcome at one year among patients with early inflammatory polyarthritis presenting to primary care using simple clinical variables measured at baseline. Satisfying the 1987 ARA criteria could not be used to predict future disability.
Subject(s)
Arthritis, Rheumatoid/diagnosis , Arthritis/diagnosis , Adult , Aged , Aged, 80 and over , Disability Evaluation , Female , Humans , Male , Middle Aged , Multivariate Analysis , Prognosis , Surveys and QuestionnairesABSTRACT
OBJECTIVE: To determine the risk of rheumatoid arthritis (RA) in first degree relatives of a true population based sample of probands with inflammatory polyarthritis. METHODS: In a case-control study, a two stage screening procedure was used to ascertain the prevalence of RA in 518 first degree relatives of 207 Norfolk Arthritis Register cases registered in 1990 and 414 first degree relatives of 180 local controls. An initial joint symptom and medical history questionnaire was followed by a physical examination, and serological and radiological evaluation of those with symptoms. RESULTS: The prevalence of RA in the first degree relatives of all the Norfolk Arthritis Register cases was 7.7/1000, compared with 4.8/1000 in the first degree relatives of the controls, with a risk ratio of 1.6 (95% confidence interval 0.3 to 8.7). This very modest increase was also seen when the analysis was restricted to the first degree relatives of Norfolk Arthritis Register cases who satisfied the American Rheumatism Association criteria for RA: prevalence rate 7.2/1000. CONCLUSION: There was no evidence of an important increased familial risk of RA in this community based sample. These data are compatible with others from immunogenetic studies showing only weak HLA associations with community ascertained RA.
Subject(s)
Arthritis, Rheumatoid/epidemiology , Arthritis, Rheumatoid/genetics , Family Health , Adolescent , Adult , Case-Control Studies , Cluster Analysis , Female , Humans , Male , Middle Aged , Prevalence , Risk Factors , Sex FactorsABSTRACT
This paper provides the first data on the incidence of RA based on a prospective population-based register. All new cases of inflammatory polyarthritis in the Norwich Health Authority are notified by general practitioners to the Norfolk Arthritis Register. The patients are then clinically evaluated by metrologists and blood taken for RF estimation. Cases of RA were defined as all those notified with an onset of symptoms in 1990; who presented by 31 December 1991; and who satisfied the 1987 ARA criteria for RA at the time of presentation. Two hundred and ten patients were notified in the defined time-frame, of whom 104 were classified as having RA. The annual incidence rate was 36/100,000 for women and 14/100,000 for men. RA was rare in men aged under 45 yr. The incidence in men rose steeply with age. The incidence in women rose up to age 45 yr, plateaued to age 75 yr, and fell in the very elderly.