Ulcerative colitis in Olmsted County, Minnesota, 1940-1993: incidence, prevalence, and survival

BACKGROUND: There is significant geographic variation in the reported incidence of ulcerative colitis. AIMS: To update the incidence and prevalence of ulcerative colitis in Olmsted County, Minnesota, examine temporal trends, and determine overall survival. PATIENTS: All Olmsted County residents diagnosed with ulcerative colitis between 1940 and 1993 (incidence cases), and all residents with ulcerative colitis alive on 1 January 1991 (prevalence cases). METHODS: Incidence and prevalence rates were adjusted using 1990 US census figures for whites. The effects of age, sex, and calendar year on incidence rates were evaluated using Poisson regression. Survival from diagnosis was compared with that expected for US north-central whites. RESULTS: Between 1940 and 1993, 278 incidence cases were identified, for an adjusted incidence rate of 7.6 cases per 100 000 person years (95% confidence interval (CI), 6.7 to 8.5). On 1 January 1991, there were 218 residents with definite or probable ulcerative colitis, for an adjusted prevalence rate of 229 cases per 100 000 (95% CI, 198 to 260). Increased incidence rates were associated with later calendar years (p<0.002), younger age (p<0.0001), urban residence (p<0.0001), and male sex (p<0.003). Overall survival was similar to that expected (p>0.2). CONCLUSIONS: The overall incidence rate of ulcerative colitis in Olmsted County increased until the 1970s, and remained stable thereafter. Incidence rates among men and urban residents were significantly higher. The prevalence rate in Rochester in 1991 was 19% higher than that in 1980. Overall survival was similar to that of the general population.     

Update on the incidence and prevalence of Crohn's disease and ulcerative colitis in Olmsted County, Minnesota, 1940-2000

BACKGROUND: We previously reported that the prevalence of Crohn's disease (CD) and ulcerative colitis (UC) in Olmsted County, Minnesota, had risen significantly between 1940 and 1993. We sought to update the incidence and prevalence of these conditions in our region through 2000. METHODS: The Rochester Epidemiology Project allows population-based studies of disease in county residents. CD and UC were defined by previously used criteria. County residents newly diagnosed between 1990 and 2000 were identified as incidence cases, and persons with these conditions alive and residing in the county on January 1, 2001, were identified as prevalence cases. All rates were adjusted to 2000 US Census figures for whites. RESULTS: In 1990-2000 the adjusted annual incidence rates for UC and CD were 8.8 cases per 100,000 (95% confidence interval [CI], 7.2-10.5) and 7.9 per 100,000 (95% CI, 6.3-9.5), respectively, not significantly different from rates observed in 1970-1979. On January 1, 2001, there were 220 residents with CD, for an adjusted prevalence of 174 per 100,000 (95% CI, 151-197), and 269 residents with UC, for an adjusted prevalence of 214 per 100,000 (95% CI, 188-240). CONCLUSION: Although incidence rates of CD and UC increased after 1940, they have remained stable over the past 30 years. Since 1991 the prevalence of UC decreased by 7%, and the prevalence of CD increased about 31%. Extrapolating these figures to US Census data, there were approximately 1.1 million people with inflammatory bowel disease in the US in 2000.     

Epidemiologic aspects of Crohn's disease: a population based study in Olmsted County, Minnesota, 1943-1982.

The overall age and sex adjusted incidence of Crohn's disease among Olmsted County, Minnesota, residents was 4.0 per 100,000 person-year in the period 1943-1982. Ileitis, ileocolitis, and colitis each accounted for about one third of the 103 incidence cases. Incidence rates were greater in woman than men, were higher in the urban portions of the county, and rose over time. Overall, the natural history of Crohn's disease in the community may be milder than that reported for patients at referral centres, as over half of all patients had no complications and only a third required surgery for Crohn's disease. Only one developed adenocarcinoma of the colon (relative risk = 2.0, NS). Survival was relatively unimpaired for the cohort, but Crohn's disease may have played a role in half of the deaths. The prevalence of Crohn's disease was 90.5/100,000 population on 1 January 1980.     

Epidemiology of polymyalgia rheumatica in olmsted county,minnesota, 1970–1991

Objective. To determine the incidence, prevalence, and survival of polymyalgia rheumatica (PMR) over a 22-year period in Olmsted County, Minnesota. Methods. Using the unified record system at the Mayo Clinic for the Olmsted County population, we reviewed all medical records with a diagnosis of PMR from 1970 through 1991. Results. There were 245 (173 female; 72 male) incidence cases of PMR between 1970 and 1991. The average annual age- and sex-adjusted incidence of PMR per 100,000 population ≥ 50 years was 52.5 (95% confidence interval [CI] 45.9–59.2), with a significantly higher incidence in females (61.7; 95% CI 52.3–71.2) than in males (39.9; 95% CI 30.7–49.2). The incidence varied over the period of observation, but no significant trends were found. The prevalence of PMR among persons ≥ 50 years on January 1, 1992 was 6/1,000. There was a small but significantly increased survival rate among male PMR patients compared with the general population. Conclusion. Our data demonstrate that PMR is a common nonfatal disease in the elderly, the incidence and clinical manifestations of which have varied but remained relatively stable over the last 2 decades.     

Trends in the incidence of polymyalgia rheumatica over a 30 year period in Olmsted County,Minnesota, USA

OBJECTIVE: To determine time trends in the incidence and survival of polymyalgia rheumatica (PMR) over a 30 year period in Olmsted County, Minnesota, USA. METHODS: Using the unified medical record linkage system of the Rochester Epidemiology Project, we identified all incident cases of PMR among residents of Olmsted County, MN, between January 1, 1970, and December 31, 1999. Incidence rates were estimated and age- and sex-adjusted to the 1990 US white population. The annual incidence rates were graphically illustrated using a 3 year centered moving average. A Poisson regression model was used to evaluate predictors of PMR incidence. Survival rates were computed and compared with the expected rates in the population. RESULTS: There were 378 incident cases of PMR during the 30 year study period. Of these 66.6% were female and the mean age at incidence was 72.8 years. The overall age and sex adjusted annual incidence of PMR per 100,000 population aged > or = 50 years was 58.7 (95% CI 52.8,64.7). Incidence rates increased with age in both sexes, but in women, unlike in men, incidence fell after age 80. The incidence rates varied over the period of observation, but no significant trends over time were found. In the multivariable analysis, sex (p = 0.023), age (p < 0.001), and age2 (p < 0.001), but not calendar year (p = 0.24) were significant predictors of incidence. Survival among individuals with PMR was not significantly different from that expected in the population (p = 0.06). CONCLUSION: The incidence of PMR has remained relatively stable over the past 30 years.     

Juvenile rheumatoid arthritis in rochester,minnesota 1960–1993. Is the epidemiology changing?

Objective. To examine trends in the incidence and prevalence of juvenile rheumatoid arthritis (JRA) in Rochester, Minnesota, over 33 years. Methods. The diagnostic retrieval system of the Rochester Epidemiology Project was utilized to screen medical records of all Rochester residents with any potential diagnoses of JRA from 1978 to 1993 (based on the American College of Rheumatology 1977 revised criteria). In addition, all cases of JRA from our previously identified cohort from 1960–1979 were verified, and the 2 data sets were combined, resulting in an incidence cohort spanning 33 years (1960–1993). Results. Of the 1,240 medical records screened, we identified 65 cases of JRA diagnosed between 1960 and 1993 (48 females, 17 males). The average followup for cases was 12.7 years (range 0–34 years) for a total of 833 person-years of observation. A bimodal distribution of age at diagnosis was observed, with peaks between 0 and 4 years and 9 and 15 years. Seventy-two percent of patients had pauciarticular-onset, 17% had polyarticular-onset, and 11% had systemic-onset disease. Progression of pauciarticular to polyarticular disease occurred in 11% of the cases. The overall age- and sex-adjusted incidence rate was 11.7 per 100,000 population (95% confidence intervals 8.7, 14.8). The incidence rate per 100,000 population was 15.0, 14.1, and 7.8 for the time periods 1960–1969, 1970–1979, and 1980–1993, respectively (P = 0.024). A 3-year, centered, moving average, which was used to display time trends in incidence, suggested a cyclical pattern, with incidence peaks in 1967, 1975, and 1987. Conclusion. An overall decrease in the incidence rate over the last decade was observed, most marked in the pauciarticular- and systemic-onset subtypes. This decrease, along with the observed cyclical pattern, suggest that environmental factors may influence disease frequency.     

Changing trends in the incidence, stage, survival, and screen-detection of colorectal cancer: a population-based study.

BACKGROUND & AIMS: Colorectal cancer (CRC) screening has been advocated increasingly during the past 2 decades, but there is little direct evidence that it has affected cancer incidence or presentation at the population level. This study assessed concurrent trends in CRC incidence, presentation, survival, mortality, and polypectomies in Olmsted County, Minnesota. METHODS: Longitudinal observational study was conducted of all Olmsted County residents with colorectal adenocarcinoma first diagnosed in 1980-1999. RESULTS: Altogether, 889 invasive CRCs were diagnosed among Olmsted County residents from 1980 through 1999. Annual age- and sex-adjusted CRC incidence rates decreased significantly during this period (P = .02) with a 23% decline from 60 per 100,000 in 1980-1984 to 46 per 100,000 in 1995-1999. This was primarily accounted for by a 40% reduction in left-sided CRC (P < .001). The incidence of right-sided CRC remained unchanged, but the proportion of right-sided CRC increased from 46% to 58%. Cancer stage shifted downward, and survival improved over time. The overall proportion of screen-detected CRC rose from 8% to 17%. Annual adjusted adenomatous polypectomy rates increased dramatically from 86 to 320 per 100,000 (P < .001). CONCLUSIONS: The incidence of CRC in Olmsted County has declined in recent years. An impact of screening is suggested by the observed upward trend in screen-detected cases, a favorable stage shift, and a concurrent rise in polypectomy rates. However, the incidence of right-sided cancer remains unaltered and might be less affected by historically used screening interventions. Most CRCs still present symptomatically, and more effective population screening is needed.     

Trends in incidence and mortality in rheumatoid arthritis in Rochester,Minnesota, over a forty‐year period

Objective

To determine time trends in the epidemiology of rheumatoid arthritis (RA) in a population‐based cohort.

Methods

An inception cohort of residents of Rochester, Minnesota ≥18 years of age who first fulfilled the American College of Rheumatology 1987 criteria between January 1, 1955 and December 31, 1994 (applied retrospectively, as appropriate) was assembled and followed up until January 1, 2000. Incidence rates were estimated and were age‐ and sex‐adjusted to the 1990 white population of the US. A birth cohort analysis was performed, and survival rates over time were examined.

Results

The incidence cohort comprised 609 patients, 445 (73.1%) of whom were female and 164 (26.9%) were male, with a mean age at incidence of 58.0 years. The overall age‐ and sex‐adjusted annual incidence of RA among Rochester, Minnesota, residents ≥18 years of age was 44.6/100,000 population (95% confidence interval 41.0–48.2). While the incidence rate fell progressively over the 4 decades of study, from 61.2/100,000 in 1955–1964, to 32.7/100,000 in 1985–1994, there were indications of cyclical trends over time. Birth cohort analysis showed diminishing incidence rates through successive cohorts following a peak in the 1880–1890 cohorts. Incidence rates increased with age until age 85, but peaked earlier in women than in men. The survival rate in RA patients was significantly lower than the expected rate in the general population (P < 0.001), and no improvement was noted over time.

Conclusion

The secular trends demonstrated in this study population, including the progressive decline in the incidence of RA over the last 40 years, suggest that an environmental factor may play a role in the etiology of RA.

     

The epidemiology of microscopic colitis: a population based study in Olmsted County, Minnesota

OBJECTIVE: Although the epidemiology of microscopic colitis has been described in Europe, no such data exist from North America. We studied the incidence, prevalence and temporal trends of microscopic colitis in a geographically defined US population. DESIGN AND SETTING: In this population based cohort study, residents of Olmsted County, Minnesota, with a new diagnosis of microscopic colitis, and all who had colon biopsies for evaluation of diarrhoea, between 1 January 1985 and 31 December 2001 were identified. Biopsies were reviewed for confirmation (cases) and to identify missed cases (diarrhoea biopsies). MAIN OUTCOME MEASURES: Incidence rates, age and sex adjusted to the 2000 US white population. Poisson regression assessed the association of calendar period, age and sex with incidence. RESULTS: We identified 130 incident cases for an overall rate of 8.6 cases per 100,000 person-years. There was a significant secular trend, with incidence increasing from 1.1 per 100,000 early in the study to 19.6 per 100,000 by the end (p<0.001). Rates increased with age (p<0.001). By subtype, the incidence was 3.1 per 100,000 for collagenous colitis and 5.5 per 100,000 for lymphocytic colitis. Collagenous colitis was associated with female sex (p<0.001) but lymphocytic colitis was not. Prevalence (per 100,000 persons) on 31 December 2001 was 103.0 (39.3 for collagenous colitis and 63.7 for lymphocytic colitis). CONCLUSIONS: The incidence of microscopic colitis has increased significantly over time, and by the end of the study, the incidence and prevalence were significantly higher than reported previously. Microscopic colitis is associated with older age, and collagenous colitis is associated with female sex.     

Exploring contrary trends in bladder cancer incidence,mortality and survival: implications for research and cancer control

Aim: To investigate trends in bladder cancer incidence, mortality and survival, and cancer–control implications. Methods: South Australian Registry data were used to calculate age‐standardized incidence and mortality rates from 1980 to 2004. Sociodemographic predictors of invasive as opposed to in situ disease were examined. Determinants of disease‐specific survival were investigated using Kaplan–Meier estimates and proportional hazards regression. Results: Incidence rates for invasive cancers decreased by 21% between 1980–84 and 2000–04, similarly affecting men and women. Meanwhile increases occurred for combined in situ and invasive disease. While mortality rates decreased by approximately a third in men and women less than 70 years of age after the early 1990s, no changes were evident for older residents. The proportion of cancers found at an in situ stage was higher in younger ages and more recent diagnostic periods. Five‐year survivals of invasive cases decreased from 64% for 1980–84 diagnoses to 58% for 1995–2004. Multivariable analysis showed that diagnostic period was not predictive of survival after age adjustment (P= 0.719), with lower survival relating to older age, transitional compared with papillary transitional cancers, female sex, indigenous status and a country as opposed to metropolitan residence. Conclusions: Reductions in invasive disease incidence may be due to increased detection at an in situ stage. The decline in survival from invasive disease in more recent periods is explained by increased age at diagnosis. Poorer outcomes of invasive cases remain for women after adjusting for age, histology, indigenous status and residential location.     

Incidence of juvenile-onset Crohn's disease in Scotland: association with northern latitude and affluence

BACKGROUND & AIMS: The incidence of Crohn's disease in Scottish children has increased steadily over 30 years. Many studies have investigated genetic influence or possible links with childhood events. We aimed to study sociodemographic and/or geographic distribution of juvenile=onset Crohn's disease in Scotland. METHODS: Using a previously established and validated database covering the entire Scottish population, 580 Scottish children (<16 years of age at symptom onset) with inflammatory bowel disease incident between 1981 and 1995 were identified. Postcodes of incident cases were classed for geographic location and material deprivation. Incidence rates (/100,000/year) were sex standardized to the 1991 census population. The effects of sex, geographic location, time, and deprivation category were estimated from a multifactorial Poisson regression model. RESULTS: The incidence of juvenile-onset Crohn's disease was 2.3 (95% CI: 2.0-2.5) for the time period 1981 to 1995 and was significantly higher in northern (3.1, 95% CI: 2.6-3.8) than in southern Scotland (2.1, 95% CI: 1.9-2.4, P < 0.001). The incidence of juvenile-onset ulcerative colitis did not show north/south variation ( P = 0.677). The relative risks of developing CD were significantly lower in postcode areas with deprivation categories 2-7 as compared with deprivation score 1 (most affluent, P = 0.033). This pattern was not seen for UC. CONCLUSIONS: There was an increased incidence of juvenile-onset Crohn's disease in northern compared with southern Scotland. Children from more affluent areas had a higher relative risk of developing Crohn's disease. Juvenile onset ulcerative colitis did not show north/south variation in incidence or association with affluence.     

Epidemiology of Crohn's disease in Israel: a survey of Israeli kibbutz settlements

OBJECTIVE: The prevalence of Crohn's disease ranges from 10 to 70 cases per 100,000 population, and is 3-8 times more common among Jews. However, this excess risk is not evident in the Jewish population of Israel. Recently we have described a significant increase in the prevalence and incidence of Crohn's disease in the south of Israel. The aim of this study was to confirm this trend in a stable population found in communal (kibbutz) settlements. METHODS: We repeated a community-based survey in 124,400 kibbutz residents, 10 yr after our first study. This population represents 5% of the Jewish population of Israel. All Crohn's disease patients were located by contacting the kibbutz clinics of the 269 kibbutz settlements (100% compliance). Data was updated to December 31st, 1997, which was designated the point prevalence date, and included information on gender, age, origin, education, profession, extent of the inflammatory process, clinical spectrum of the disease, therapy, complications of the disease, and treatment. The average annual incidence for the 10 yr was calculated from the prevalence data. Only cases with a definite diagnosis of Crohn's disease made in a recognized gastroenterology unit were accepted into the study. RESULTS: There were 81 confirmed cases of Crohn's disease and the prevalence rate rose from 25.5/100,000 in 1987 to 65.1/100,000 in 1997 (p < 0.001). The mean annual incidence rate for this period (1987-1997) is 5.0/100,000/yr. Prevalence rates were higher in women than men, and in those born in Israel or Europe/America than in Asia/Africa. The mean age at presentation of the disease was lower in 1997 than in 1987, 37.4 +/- 17.0 and 45.0 +/- 17.0 yr, respectively (p = 0.041). Prevalence was highest in men with > 16 yr of education, and in women with 11-12 yr education, 119.7 and 100.3/100,000, respectively. CONCLUSIONS: During the decade 1987-1997, the prevalence of Crohn's disease has increased in Israel and is approaching the rates in Europe and America.     

Opposite evolution in incidence of Crohn's disease and ulcerative colitis in Northern France (1988-1999)

BACKGROUND: Northern France was characterised by a high incidence of Crohn's disease (CD) and a low incidence of ulcerative colitis (UC) according to the first inquiry undertaken in the late 1980s. AIMS: To assess the trends in the incidence of inflammatory bowel disease (IBD) over a 12 year period (1988-1999) in the same area of Northern France. PATIENTS: Patients living in Northern France (Nord, Pas-de-Calais, Somme, and Seine Maritime--total of 5,790,526 inhabitants) between 1988 and 1999 were included in the study. Case ascertainment was established according to methodology previously described. METHODS: Trends in incidence were studied using a Poisson regression model in four three year periods (1988-90, 1991-93, 1994-96, and 1997-99) adjusted for age at diagnosis and sex. Incidence rates were standardised for age with the European standard population. RESULTS: During 1988-99, 7066 cases of IBD were recorded (56.8% CD, 37.7% UC, and 5.5% indeterminate colitis). Mean annual incidence rate of CD increased from 5.2/100,000 inhabitants in 1988-90 to 6.4 in 1997-99 (adjusted p for trend <0.001). In contrast, the incidence of UC decreased from 4.2 to 3.5 (adjusted p for trend <0.001). The ileocolonic subtype of CD increased by 25% even though median age at diagnosis and frequency of digestive investigations were not different. CONCLUSIONS: Contrary to what has been reported in other countries in Northern Europe, the incidence of CD increased by 23% in 12 years in Northern France while that of UC decreased by 17% during the same period. This indicates that some factors which influence IBD frequency (in both directions) are still at work in this area of Europe, and that further studies aimed at identifying these should be performed. The rising incidence of CD could enhance the burden of this disease on the public health system in France.     

Trends in incidence and mortality in rheumatoid arthritis in Rochester, Minnesota, over a forty-year period

OBJECTIVE: To determine time trends in the epidemiology of rheumatoid arthritis (RA) in a population-based cohort. METHODS: An inception cohort of residents of Rochester, Minnesota > or = 18 years of age who first fulfilled the American College of Rheumatology 1987 criteria between January 1, 1955 and December 31, 1994 (applied retrospectively, as appropriate) was assembled and followed up until January 1, 2000. Incidence rates were estimated and were age- and sex-adjusted to the 1990 white population of the US. A birth cohort analysis was performed, and survival rates over time were examined. RESULTS: The incidence cohort comprised 609 patients, 445 (73.1%) of whom were female and 164 (26.9%) were male, with a mean age at incidence of 58.0 years. The overall age- and sex-adjusted annual incidence of RA among Rochester, Minnesota, residents > or = 18 years of age was 44.6/100,000 population (95% confidence interval 41.0-48.2). While the incidence rate fell progressively over the 4 decades of study, from 61.2/100,000 in 1955-1964, to 32.7/100,000 in 1985-1994, there were indications of cyclical trends over time. Birth cohort analysis showed diminishing incidence rates through successive cohorts following a peak in the 1880-1890 cohorts. Incidence rates increased with age until age 85, but peaked earlier in women than in men. The survival rate in RA patients was significantly lower than the expected rate in the general population (P < 0.001), and no improvement was noted over time. CONCLUSION: The secular trends demonstrated in this study population, including the progressive decline in the incidence of RA over the last 40 years, suggest that an environmental factor may play a role in the etiology of RA.     

Increase in incidence and prevalence of inflammatory bowel disease in northern Denmark: a population-based study, 1978-2002

OBJECTIVES: Although incidence rates of inflammatory bowel disease have been reported worldwide, few long-term population-based studies with current time-trend analyses exist. We therefore examined time trends in the incidence rate of inflammatory bowel disease in a 25-year study period, and estimated the prevalence in 2002. All patients diagnosed between 1978 and 2002 were included as incident cases (n=2,326) and all patients living in North Jutland County on 31 December 2002 were used to estimate prevalent cases (n=2,205). METHODS: Medical records of all patients diagnosed with ulcerative colitis and Crohn's disease in the North Jutland County Hospital Discharge Registry were reviewed to examine if the diagnostic criteria were fulfilled. Age-specific and gender-specific standardized incidence rates were calculated. RESULTS: For ulcerative colitis, incidence rates in women increased from 8.3 (95% confidence interval (CI): 6.7-9.9) in 1978-1982 to 17.0 (95% CI: 14.7-19.3) per 100,000 person-years in 1998-2002. The corresponding figures for men were 7.7 (95% CI: 6.1-9.3) and 16.7 (95% CI: 14.4-18.8) per 100,000 person-years. For Crohn's disease, the incidence rates in women increased from 4.1 (95% CI: 3.0-5.2) in 1978-1982 to 10.7 (95% CI: 8.8-12.5) per 100,000 person-years in 1998-2002. The corresponding figures for men were 3.2 (95% CI: 2.1-4.2) and 8.5 (95% CI: 6.9-10.2) per 100,000 person-years. The prevalence of ulcerative colitis and Crohn's disease was 294 and 151 per 100,000 inhabitants, respectively. CONCLUSIONS: A marked and parallel increase was seen in both ulcerative colitis and Crohn's disease in both genders during the last 25 years, with a corresponding high prevalence of both diseases.     

Increasing incidence of both juvenile-onset Crohn's disease and ulcerative colitis in Scotland.

OBJECTIVE: A previous study reported a three-fold rise in the incidence of juvenile-onset Crohn's disease in Scottish children and a marginal fall in ulcerative colitis between 1968 and 1983. The present study aimed to document the incidence of juvenile-onset inflammatory bowel disease between 1981 and 1995 and examine temporal trends between 1968 and 1995 in Scotland. SETTING: Scotland (latitude 55-60 degrees N) has a total area of 77 837 km2 (30 405 square miles) and includes four urban centres each with a population of over 100,000. PARTICIPANTS: The Scottish hospital discharges linked database was used to identify 1002 patients less than 19 years old who were coded as having inflammatory bowel disease between 1981 and 1997. All case notes were reviewed and diagnoses verified. Incident cases were defined as those with symptom onset before or at 16 years of age between 1 January 1981 and 31 December 1995. RESULTS: During the 15 year period 1981-1995, 438 incident cases of Crohn's disease and 227 of ulcerative colitis were identified, giving standardized incidences of 2.5 cases and 1.3 cases per 100,000 population per year for Crohn's disease and ulcerative colitis respectively. On 31 December 1995 there were 150 children < or = 16 years of age with Crohn's disease and 101 with ulcerative colitis, giving crude prevalences of 13.7 cases per 100,000 population for Crohn's disease and 9.2 for ulcerative colitis. The continuing rise in Crohn's disease incidence between 1981 and 1995 fits that predicted by linear trend analysis of the 1968-1983 data. The incidence of Crohn's disease in the 12-16 age range almost doubled between 1981 and 1995 and was greater for males than females. Ulcerative colitis incidence was thought to show a slight fall in the 1968-1983 data, but this is reversed in the 1981-1995 data. CONCLUSION: The incidence of juvenile-onset Crohn's disease continues to rise in Scotland and the prevalence has increased by 30% since 1983. Unlike the previous report from Scotland, the incidence of juvenile-onset ulcerative colitis also is apparently rising. Whether this represents a real rise in incidence, or merely the inclusion of milder cases which were not previously hospitalized remains uncertain.     

Evaluation of surgery for perianal Crohn's fistulas

PURPOSE: This study was designed to evaluate the operative treatments performed on patients with perianal Crohn's disease at a tertiary referral colorectal university hospital and to determine the efficacy of management by assessing patient satisfaction. METHODS: A retrospective survey included 59 patients with perianal Crohn's disease who had undergone surgery during the period of 1991 to 1993, inclusive. RESULTS: Twenty-seven patients were treated by laying the fistula open (81 percent successful), and another 27 cases were treated with a loose seton (85 percent successful). Five cases were complicated fistulas and underwent diversionary stomas as part of a primary procedure. Overall success rate, as judged by patient satisfaction, was 83 percent. CONCLUSION: Conservative surgery has a role in management of perianal Crohn's disease. Patient satisfaction can be achieved without complete healing. Better preoperative assessment may improve results further.     

Reappraisal of the epidemiology of giant cell arteritis in Olmsted County, Minnesota, over a fifty-year period

OBJECTIVE: To investigate time trends in the incidence and survival of giant cell arteritis (GCA) over a 50-year period in Olmsted County, Minnesota. METHODS: Using the unified record system at the Mayo Clinic, we identified all incident cases of GCA first diagnosed between 1950 and 1999. Incidence rates were estimated and adjusted to the 1980 United States white population for age and sex. The annual incidence rates were graphically illustrated using a 3-year centered moving average. Survival rates were computed and compared with the expected rates in the population. RESULTS: There were 173 incident cases of GCA during the 50-year study period. Of these, 79% were women and the mean age at diagnosis was 74.8 years. The overall age- and sex-adjusted incidence per 100,000 persons 50 years of age or older was 18.8 (95% confidence interval [95% CI] 15.9-21.6). Incidence was higher in women (24.4; 95% CI 20.3-28.6) than in men (10.3; 95% CI 6.9-13.6). Incidence rates increased significantly over the study period (P = 0.017); in particular, a progressive increase was observed from 1950 to 1979; subsequently, no substantial increases in incidence rates were observed. A cyclic pattern of annual incidence rates was apparent, with evidence of 6 peak periods. Survival among individuals with GCA was not significantly different from that expected in the population (P = 0.80). CONCLUSIONS: The incidence of GCA increased over the first 3 decades of the study, then remained stable over the last 20 years. The previously observed cyclic pattern of annual incidence rates was still apparent over a 50-year period. Overall survival in GCA was similar to that in the population.     

Trends in the incidence of polycythemia vera among olmsted county,Minnesota residents, 1935–1989

To investigate the suggestion that the incidence of polycythemia vera has increased in recent decades, we ascertained secular trends in the incidence of polycythemia vera in Olmsted County, Minnesota, over the 55-year period, 1935–1989. The inpatient and outpatient medical records of all potential cases of polycythemia vera in Olmsted County residents were reviewed and the diagnostic criteria of the Polycythemia Vera Study Group were applied. We found no indication of an increase in the age- and sex-adjusted incidence of polycythemia vera, which averaged 1.9 per 100,000 person-years (95% C.I., 1.4–2.5) over the study period. Incidence rates increased with age, and age-adjusted incidence rates were greater for men (2.8 per 100,000 person-years; 95% C.I., 1.8–3.9) than for women (1.3 per 100,000 person-years; 95% C.I., 0.7–1.9), with the highest incidence rate (23.5 per 100,000 person-years) among men aged 70–79 years. Survival was reduced in this inception cohort of 50 cases, compared to that expected for individuals of like age and sex (P < 0.0001); median survival following diagnosis was 7.2 years. © 1994 Wiley-Liss, Inc.     

Reappraisal of the epidemiology of giant cell arteritis in Olmsted County,Minnesota, over a fifty‐year period

Objective

To investigate time trends in the incidence and survival of giant cell arteritis (GCA) over a 50‐year period in Olmsted County, Minnesota.

Methods

Using the unified record system at the Mayo Clinic, we identified all incident cases of GCA first diagnosed between 1950 and 1999. Incidence rates were estimated and adjusted to the 1980 United States white population for age and sex. The annual incidence rates were graphically illustrated using a 3‐year centered moving average. Survival rates were computed and compared with the expected rates in the population.

Results

There were 173 incident cases of GCA during the 50‐year study period. Of these, 79% were women and the mean age at diagnosis was 74.8 years. The overall age‐ and sex‐adjusted incidence per 100,000 persons 50 years of age or older was 18.8 (95% confidence interval [95% CI] 15.9–21.6). Incidence was higher in women (24.4; 95% CI 20.3–28.6) than in men (10.3; 95% CI 6.9–13.6). Incidence rates increased significantly over the study period (P = 0.017); in particular, a progressive increase was observed from 1950 to 1979; subsequently, no substantial increases in incidence rates were observed. A cyclic pattern of annual incidence rates was apparent, with evidence of 6 peak periods. Survival among individuals with GCA was not significantly different from that expected in the population (P = 0.80).

Conclusions

The incidence of GCA increased over the first 3 decades of the study, then remained stable over the last 20 years. The previously observed cyclic pattern of annual incidence rates was still apparent over a 50‐year period. Overall survival in GCA was similar to that in the population.