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

Jejunoileal Crohn's disease: a case-control study

AIMS

Jejunoileitis might be a severe form of Crohn's disease (CD). The aim of the study was to evaluate clinical characteristics, therapeutics modalities and long-term outcome in CD patients with jejunoileitis (CDJI).

METHODS

All patients with CDJI followed in the department of Gastroenterology from 1963 to 1999 were included and compared to matched (on Year of CD diagnosis) CD controls without jejunoileitis. Data were obtained from retrospective review of medical charts.

RESULTS

Eighteen patients with CDJI were compared to 36 matched CD controls. Median follow-up was 7.65 Years in both groups. At time of CDJI diagnosis the following signs were significantly more frequent in patients with jejunoileal CD than in controls: malnutrition (39% vs 3%), pain suggesting obstruction (33% vs 8%), vomiting (28% vs 5%). Patients with CDJI were more frequently male: M/F ratio=2.0/1.1 (P=0.33). Upper digestive involvement (esophagus, stomach and duodenum) (67% vs 36%, P=0.04) and small intestine strictures (61% vs 19%, P=0.06) were more frequent in CDJI. Initial management was more "aggressive" in CDJI than in controls: steroids in 62% vs 30%, azathioprine in 39% vs 3%, total parenteral nutrition in 28% vs 8% and surgery in 33% vs 17%. During follow-up, the need for azathioprine therapy and surgery were more frequent in CDJI than in controls (extensive small bowel resection in two patients). In 10 of 18 patients, jejunoileitis involvement was diagnosed with a median delay of 3.6 Years (range: 0.5-14.5) after CD diagnosis and at time of CD diagnosis in the 8 others; outcome after CDJI diagnosis was similar in these 2 groups.

CONCLUSION

The main revealing signs of jejunoileitis in CD patients are obstruction and malnutrition. Patients with CDJI require more often azathioprine and surgery than CD patients without jejunoileitis. Jejunoileitis is a severe form of CD more frequently complicated by extensive small bowel resection.

Intestinal and extra-intestinal cancer in Crohn's disease: follow-up of a population-based cohort in Copenhagen County, Denmark

AIM

To determine the long-term risk of intestinal and extra-intestinal malignancies in Crohn's disease patients in Copenhagen County, Denmark.

METHODS

In Copenhagen County, a strictly population-based cohort of 374 patients with Crohn's disease diagnosed between 1962 and 1987 was followed until 1997 in order to determine the long-term risk of intestinal and extra-intestinal malignancies. Information on cancer occurrence was provided by the Danish National Cancer Registry and confirmed by the examination of hospital files. The observed number of cases was compared with the expected number, calculated from individually computed person-years at risk and 1995 cancer incidence rates for the background population.

RESULTS

The risk of small bowel adenocarcinoma was significantly increased, independent of age and gender (standardized morbidity ratio, 66.7; 95% confidence interval, 18.1-170.7). The risk of colorectal cancer was not increased, either in the total group of patients or in patients with colonic Crohn's disease exclusively (standardized morbidity ratio, 1.64; 95% confidence interval, 0.20-5.92). Extra-intestinal cancer did not occur more frequently than expected.

CONCLUSIONS

This population-based study of patients with Crohn's disease revealed no increase in colorectal cancer risk, possibly due to maintenance treatment with 5-aminosalicylic acid preparations and surgery in treatment failure. In contrast, the risk of small bowel cancer was increased more than 60-fold, but the numbers were small. The risk of extra-intestinal cancer was not increased and no lymphomas were observed.

Combined terminal ileoscopy and biopsy is superior to small bowel follow-through in detecting terminal ileal pathology

BACKGROUND

Several studies have compared small bowel barium examination with ileoscopy in assessment of terminal ileal disease. Some suggest that ileoscopy is superior in detection of terminal ileal disease whereas others suggest similar disease detection rates for both techniques.

AIMS

The aim of this retrospective study was to determine if small bowel follow-through and ileoscopy with terminal ileum biopsy compare favourably at detecting pathology in the terminal ileum.

PATIENTS AND METHODS

All colonoscopies with terminal ileoscopy performed over a 16-month period were reviewed. We determined which of these patients had also had small bowel follow-through studies within 2 weeks of colonoscopy. We compared the diagnoses of terminal ileum pathology using ileoscopy with terminal ileal biopsy versus small bowel follow-through.

RESULTS

Forty-six patients had both terminal ileoscopy with biopsy and small bowel follow-through. In 19 patients, the terminal ileum was abnormal at ileoscopy and/or biopsy but normal at small bowel follow-through. In 27 patients, terminal ileum findings at small bowel follow-through and at ileoscopy and/or biopsy were compatible.

CONCLUSIONS

This study suggests that examination of the terminal ileum by combined ileoscopy and biopsy may be superior to small bowel follow-through at detecting terminal ileal pathology. In our series, many patients received effective treatment that otherwise would not have been offered based on the small bowel follow-through results alone. Using combined ileoscopy and biopsy, microscopic inflammatory changes, otherwise missed without biopsy, can be detected. Retrograde ileoscopy is recommended in patients with a clinical history of organic diarrhoea and/or abdominal pain even in the presence of a normal small bowel follow-through.

Strategies for detecting colon cancer and/or dysplasia in patients with inflammatory bowel disease

BACKGROUND

Patients with longstanding ulcerative colitis and colonic Crohn's disease have an increased risk of colorectal cancer compared with the general population. This review assesses the evidence that endoscopic surveillance may prolong life by allowing earlier detection of colon cancer or its pre-cursor lesion, dysplasia in patients with inflammatory bowel disease.

OBJECTIVES

To assess the effectiveness of cancer surveillance programs in reducing the death rate from colorectal cancer in patients with ulcerative colitis and colonic Crohn's disease.

SEARCH STRATEGY

The following strategies were used to identify relevant studies: 1. MEDLINE and the Cochrane Central Register of Controlled Trials were searched from 1966 to December 2002. The medical subject headings "Ulcerative Colitis", "Crohn Disease" or "Inflammatory Bowel Disease" and "Surveillance" or "Cancer" were used to perform key-word searches of the databases. 2. Hand searching of reference lists from papers.

SELECTION CRITERIA

Potentially relevant articles were reviewed independently and unblinded by three authors to determine if they fulfilled the selection criteria. Each article was rated as being eligible, ineligible, or without sufficient information to determine eligibility. Any disagreement between reviewers was resolved by consensus. Any trials published in abstract form were only considered if it was possible to obtain full details of the protocol and results from the authors.

DATA COLLECTION AND ANALYSIS

Eligible articles were reviewed in duplicate and the results of the primary research trials were abstracted onto specially designed data extraction forms. The proportion of patients dying from bowel cancer or other causes in the control and surveillance groups of each study was derived from life tables, survival curves or where possible, by calculating life tables from the data provided. Data from the original research articles were converted into 2x2 tables (survival versus death x surveillance versus control) for each of the individual studies for comparable follow-up intervals. The presence of significant heterogeneity among studies was tested by the chi-square test. Because this is a relatively insensitive test, a p value of less than 0.1 was considered statistically significant. Provided statistical heterogeneity was not present (p>0.10), the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled relative risk (RR) and 95% confidence intervals as described by Cochrane and Mantel and Haenszel.

MAIN RESULTS

Karlen 1998a found that 2/40 of the patients dying of colorectal cancer had undergone surveillance colonoscopy on at least one occasion compared with 18/102 of the controls (RR 0.28, 95% confidence interval 0.07 to 1.17). One of 40 patients who died from colorectal cancer had undergone surveillance colonoscopies on two or more occasions compared with 12/102 controls (RR 0.22, 95% confidence interval 0.03 to 1.74) in contrast to a more modest effect observed for patients who had only one colonoscopy (RR 0.43, 95% confidence intervals 0.05 to 3.76). Choi 1993 found that carcinoma was detected at a significantly earlier stage in the surveillance group; 15/19 had Duke's A or B carcinoma in the surveilled group compared to 9/22 in the non-surveilled group (P= 0.039). The 5-year survival rate was 77.2% for cancers occurring in the surveillance group and 36.3% for the no-surveillance group (P= 0.026). Four of 19 patients in the surveillance group died from colorectal cancer compared to 11 of 22 patients in the non-surveillance group (RR 0.42, 95% CI 0.16 to 1.11). Lashner 1990 found that four of 91 patients in the surveillance group died from colorectal cancer compared to 2 of 95 patients in the non-surveilled group (RR 2.09, 95% CI 0.39 to 11.12). Colectomy was less common in the surveillance group, 33 compared to 51 (p < 0.05) and was performed four years later (after 10 years of disease) in the surveillance group. For the pooled data analysis 8/110 patients in the surveillance group died from colorectal cancer compared to 13/117 patients in the non-surveillance group (RR 0.81, 95% CI 0.17 to 3.83).

REVIEWERS' CONCLUSIONS

There is no clear evidence that surveillance colonoscopy prolongs survival in patients with extensive colitis. There is evidence that cancers tend to be detected at an earlier stage in patients who are undergoing surveillance and these patients have a correspondingly better prognosis but lead-time bias could contribute substantially to this apparent benefit. There is indirect evidence that surveillance is likely to be effective at reducing the risk of death from IBD-associated colorectal cancer and indirect evidence that it is acceptably cost-effective.

Inflammatory bowel disease and hospital treatment in Italy: the RING multi-centre study

AIM

To explore the management of chronic inflammatory bowel disease, specifically Crohn's disease and ulcerative colitis, in Italian gastroenterology units.

METHODS

The RING (Ricerca Informatizzata in Gastroenterologia) project is an observational study collecting hospital discharge forms from 56 centres. Factors associated with the length of hospital stay were studied using multivariate logistic regression.

RESULTS

In 24 months starting from August 2000, out of 29,376 hospital discharge forms, 2131 (7.3%) were collected for inflammatory bowel disease (1163 for Crohn's disease and 968 for ulcerative colitis). The Crohn's disease and ulcerative colitis groups were compared according to demographic characteristics, diagnoses, procedures and hospital stay. In Crohn's disease, computed tomography/magnetic resonance imaging, x-rays/barium enema, number of procedures and number of diagnoses were significantly associated with a hospital stay longer than 10 days. In ulcerative colitis, this association was found for parenteral nutrition, malnutrition, computed tomography/magnetic resonance imaging and number of procedures.

CONCLUSIONS

Crohn's disease was confirmed as a disabling disorder requiring more frequent hospital treatment than ulcerative colitis. For the latter, parenteral nutrition and malnutrition were related to a longer hospital stay. The number of procedures, especially abdominal computed tomography/magnetic resonance imaging, was a major item for both pathologies.

Anal and rectal cancer in Crohn's disease

Several epidemiological studies have been published regarding the risk of Crohn's disease- associated colorectal cancer. The findings are, however, contradictory and it has been particularly difficult to obtain indisputable information on the incidence of cancer limited to the rectum and the anus. During 1987-2000 rectal or anal cancer was diagnosed in 335 patients in Sweden (153 males, 182 females). In other words, approximately 3 Crohn patients per million inhabitants were diagnosed with rectal or anal cancer every year during that time period which is 1% of the total number of cases. At diagnosis of cancer 36% were aged below 50 years and 58% below 60 years. Corresponding figures for all cases of anal and rectal cancer were 5% and 18%, respectively. Present knowledge from the literature implies that there is an increased risk of rectal and anal cancer only in Crohn's disease patients with severe proctitis or severe chronic perianal disease. However, the rectal remnant must also be considered a risk factor. Multimodal treatment is similar to that in sporadic cancer but proctectomy and total or partial colectomy is added depending on the extent of the Crohn's disease. The outcome is the same as in sporadic cancer at a corresponding stage but the prognosis is often poor due to the advanced stage of cancer at diagnosis. We suggest that six high-risk groups should be recommended annual surveillance after a duration of Crohn's disease of 15 years including extensive colitis, chronic severe anorectal disease, rectal remnant, strictures, bypassed segments and sclerosing cholangitis.

Prevalence of gastrointestinal diseases in two British national birth cohorts

BACKGROUND

Few studies have investigated the prevalence of multiple gastrointestinal diseases in the general British population.

AIM

To examine the prevalence of Crohn's disease (CD), ulcerative colitis (UC), irritable bowel syndrome (IBS), gall stones (GS), and peptic ulcer disease (PUD).

SUBJECTS

The 1970 British Cohort Study (BCS70) and the National Child Development Study (NCDS) are two one week national birth cohorts born in 1970 and 1958, respectively. All cohort members living in Great Britain were interviewed in 1999/2000.

METHODS

The prevalence rates of the five diseases were calculated, and associations with sex and childhood social class were investigated using logistic regression.

RESULTS

At age 30 years, the prevalence rates per 10,000 (95% confidence interval (CI)) in the 1970 and 1958 cohorts, respectively, were: CD 38 (26-49), 21 (13-30); UC 30 (20-41), 27 (18-37); IBS 826 (775-877), 290 (267-330); GS 88 (71-106), 78 (62-94); and PUD 244 (214-273), 229 (201-256). There was a significantly higher proportion with CD (p=0.023) and IBS (p=0.000) in the 1970 cohort compared with the 1958 cohort at age 30 years. Comparing the cohorts in the 1999/2000 sweep, UC, GS, and PUD were significantly (p=0.001, p=0.000, p=0.000) more common in the 1958 cohort. There was a statistically significant trend for a higher risk of GS with lower social class in both cohorts combined (p=0.027).

CONCLUSION

The study indicates an increasing temporal trend in the prevalence of CD and suggests a period effect in IBS, possibly due to adult life exposures or variation in recognition and diagnosis of IBS.

Long-term fracture risk in patients with Crohn's disease: a population-based study in Olmsted County, Minnesota

BACKGROUND & AIMS

Osteoporosis is common in patients with Crohn's disease, but less is known about their risk of actual fractures.

METHODS

The medical records of all 238 Olmsted County, Minnesota, residents diagnosed with Crohn's disease between 1940 and 1993 were reviewed for evidence of subsequent fractures compared with a control group of county residents matched by age and sex. The risk ratio of fracture in patients relative to controls was estimated using the Cox proportional hazards regression model. The cumulative incidence of fracture following diagnosis was estimated using the Kaplan-Meier method.

RESULTS

Sixty-three patients had 117 different fractures. The cumulative incidence of any fracture from the time of diagnosis onward was 36% at 20 years versus 32% in controls (P = 0.792). Compared with controls, the overall risk ratio for any fracture was 0.9 (95% confidence interval [CI], 0.6-1.4), whereas the relative risk for an osteoporotic fracture was 1.4 (95% CI, 0.7-2.7). The risk ratio for thoracolumbar vertebral fracture was 2.2 (95% CI, 0.9-5.5). Cox proportional hazards regression identified only age as a significant clinical predictor of fracture risk (hazard ratio per 10-year increase in age, 1.3; 95% CI, 1.1-1.5). Specifically, use of corticosteroids and surgical resection did not predict risk of fracture among these unselected patients with Crohn's disease from the community.

CONCLUSIONS

In this population-based inception cohort of patients with Crohn's disease, the risk of fracture was not elevated relative to age- and sex-matched controls.

Epidemiology of inflammatory bowel disease

The incidence of IBD has either continued to increase or has stabilized at a high rate in most developed countries, whereas the incidence continues to rise in regions where IBD had been less common. The prevalence has continued to increase as a result of a combination of previously rising incidence and improved survival. Regardless of the exact prevalence, the burden of disease in North America and Europe is significant. Studying the patterns of geographic variation and age and gender distribution may yield important clues to the cause of IBD.

Cancer in inflammatory bowel disease. An evidence-based analysis and guide for physicians and patients

The risk of cancer in IBD is real and is a cause of anxiety and concern among patients and practitioners. Current modalities for detecting dysplasia in IBD are crude and insensitive and subject to observer and sampling bias. This evidence-based review confirms a significant increased risk for colorectal cancer among patients with pancolonic UC and, to a lesser extent, in patients with left-sided disease. Risk increases with longer duration of disease; early age at diagnosis; coexisting PSC; and, perhaps, a family history of colorectal cancer. Physicians must pay greater attention to the manner in which they implement surveillance colonoscopies, including paying heed to the location and number of biopsy specimens required to maximize the benefit. With respect to CD, the evidence suggests that patients with extensive colonic involvement of long duration carry a similar risk of colorectal cancer to patients with UC and should be considered candidates for surveillance colonoscopy.

Measles vaccination and inflammatory bowel disease: controversy laid to rest?

The increasing incidence of Crohn's disease has lead to speculation about changes in exposures to environmental or infectious agents. Considerable attention has focused on the role of measles infection and/or vaccination in the pathogenesis of Crohn's disease and ulcerative colitis. Current evidence regarding the association between measles vaccination and inflammatory bowel disease (IBD) comprises analytic epidemiological studies, a case-series report and ecological studies. The first of these, a 1995 cohort study, found an association between measles vaccination and Crohn's disease and ulcerative colitis, but was widely questioned on methodological grounds. This was followed by a 1997 case-control study showing no association between measles vaccination and IBD. In 1998, public concern was rekindled by a report of 12 children with nonspecific colitis, ileal-lymphoid-nodular hyperplasia, and developmental disorders largely attributed to measles-mumps-rubella vaccine, but the nature of the report limited its scientific conclusions. Two additional studies, one case-control and one cohort, then followed and neither found an association with measles vaccination. Of the several ecological studies of measles vaccine coverage or measles schedule changes, none found an association with rates of IBD. The role of measles infection in IBD has been examined more extensively with studies of in utero measles exposure, measles infection early in life, and laboratory based investigations. An initial report of high rates of Crohn's disease among pregnancies affected by measles infection was followed by negative studies. Numerous case-control and ecological studies of children with measles infections early in life have also had discordant findings. Of three recent cohort studies, two showed no relationship between infection with early measles exposure and risk for IBD, while one found an approximate 3-fold elevation in risk. Laboratory investigations into persistent measles infection and IBD have been contentious. While some investigators have claimed to find persistent measles infection among patients with IBD, others, using highly sensitive polymerase chain reaction techniques, have not been able to replicate the findings. Recent controversy has centred on whether there is any evidence for molecular mimicry in the pathogenesis of IBD. In summary, available evidence does not support an association between measles-containing vaccines and risk of IBD, nor between measles infection and IBD. While further research is necessary into the causal factors underlying Crohn's disease and ulcerative colitis, continued public education efforts are needed to reassure the public about vaccine safety and to prevent declines in vaccine coverage.

The epidemiology and natural history of Crohn's disease in population-based patient cohorts from North America: a systematic review

AIM

To quantify, through systematic review, the epidemiology and natural history of Crohn's disease in North America.

METHODS

The selected articles contained: (i) population-based samples of patients followed from the time of diagnosis; and (ii) objective diagnostic criteria for disease. Studies on the natural history of Crohn's disease also contained sufficient follow-up.

DATA COLLECTION AND ANALYSIS

For prevalence studies, data on the incidence, prevalence, gender and age at diagnosis were extracted. For natural history studies, data on the disease activity, use of medications and surgery were extracted.

MAIN RESULTS

The prevalence of Crohn's disease in North America ranges from 26.0 to 198.5 cases per 100,000 persons. The incidence rates range from 3.1 to 14.6 cases per 100,000 person-years. Most patients have a chronic intermittent disease course, while 13% have an unremitting disease course and 10% have a prolonged remission. Less than half require corticosteroids at any point. During any given year, approximately 10% are treated with corticosteroids and 30% are treated with 5-aminosalicylates. Up to 57% of patients require at least one surgical resection.

CONCLUSIONS

Between 400,000 and 600,000 patients in North America have Crohn's disease, and the natural history is marked by frequent exacerbations requiring treatment with corticosteroids, 5-aminosalicylate products and surgery.

Evaluation of serologic disease markers in a population-based cohort of patients with ulcerative colitis and Crohn's disease

BACKGROUND

The sensitivity of assays for antineutrophil cytoplasmic antibody (ANCA), anti-Saccharomyces cerevisiae antibody (ASCA), and antipancreatic antibody (PAB) in different laboratories is unknown. Likewise, the sensitivity and diagnostic usefulness of these assays in patients with inflammatory bowel disease (IBD) in the community is unknown.

METHODS

An incidence cohort of 290 patients with IBD were offered participation in the study. Blood was obtained from 162 patients (56%) (83 with ulcerative colitis, 79 with Crohn's disease) who agreed to participate. ANCA was determined in five laboratories. ASCA in two laboratories, and PAB in one laboratory.

RESULTS

In ulcerative colitis, the sensitivity of ANCA determined in five laboratories varied widely, ranging from 0-63%. In Crohn's disease, the sensitivity of ASCA determined in two laboratories did not vary significantly, ranging from 39-44%; and the sensitivity of PAB determined in one laboratory was 15%. The optimal diagnostic usefulness was obtained from one laboratory where the positive predictive values of a positive ANCA assay combined with a negative ASCA assay for ulcerative colitis, and a negative ANCA combined with a positive ASCA for Crohn's disease, were 75% and 86%, respectively.

CONCLUSIONS

In patients with IBD, the sensitivity of ANCA varied widely in different laboratories, whereas the prevalence of ASCA was similar. The positive predictive values of the ANCA assay combined with the ASCA assay for ulcerative colitis and Crohn's disease are high enough to be clinically useful.

Cancer risk in patients with inflammatory bowel disease: a population-based study

BACKGROUND

The objective of the current study was to determine the incidence of cancer among persons with inflammatory bowel disease (IBD) and to compare these incidence rates with those of the non-IBD population using population-based data from the administrative claims data of Manitoba's universal provincial insurance plan (Manitoba Health).

METHODS

IBD patients were matched 1:10 to randomly selected members of the population without IBD based on year, age, gender, and postal area of residence. The incidence of cancer was determined by linking records from the IBD and non-IBD cohorts with the comprehensive Cancer Care Manitoba registry. Incidence rates and rate ratios (IRR) were calculated based on person-years of follow-up (Crohn's disease = 21,340 person-years and ulcerative colitis [UC] = 19,665 person-years) for 1984-1997.

RESULTS

There was an increased IRR of colon carcinoma for both Crohn disease patients (2.64; 95% confidence interval [95% CI], 1.69-4.12) and UC patients (2.75; 95% CI, 1.91-3.97). There was an increased IRR of rectal carcinoma only among patients with UC (1.90; 95% CI, 1.05-3.43) and an increased IRR of carcinoma of the small intestine only in Crohn disease patients (17.4; 95% CI, 4.16-72.9). An increased IRR of extraintestinal tumors was observed only for the liver and biliary tract in both Crohn disease patients (5.22; 95% CI, 0.96-28.5) and UC patients (3.96; 95% CI, 1.05-14.9). There was an increased IRR of lymphoma for males with Crohn disease only (3.63; 95% CI, 1.53-8.62), and this finding did not appear to be related to use of immunomodulatory therapy. Compared with controls, Crohn's disease was associated with an increased risk of cancer overall, but UC was not.

CONCLUSIONS

There appear to be similar increased risks for developing colon carcinoma and hepatobiliary carcinoma among patients with Crohn disease and UC. There is an increased risk of developing rectal carcinoma in UC patients, an increased risk of developing carcinoma of the small bowel in Crohn disease patients, and an increased risk of developing lymphoma among males with Crohn disease.

Screening and surveillance colonoscopy in chronic Crohn's colitis

BACKGROUND & AIMS

Unlike ulcerative colitis, there are few reports on the efficacy of surveillance colonoscopy in patients with chronic Crohn's colitis and therefore little agreement as to whether routine surveillance is indicated. We report on 259 patients with chronic Crohn's colitis who underwent screening and subsequent surveillance colonoscopy and biopsy since 1980.

METHODS

Biopsies were performed at 10-cm intervals and from strictures and polypoid masses. Pathology was classified as normal, dysplasia (indefinite, low-grade, high-grade), or carcinoma.

RESULTS

A total of 663 examinations were performed on 259 patients. The median interval between examinations was 24 months; examinations were performed more frequently (1-6 months) in patients with dysplasia on biopsy. A thinner-caliber colonoscope was required to complete 12% of screening examinations and 23% of surveillance examinations. The pediatric colonoscope helped increase our yield of neoplasia by 19%. The screening and surveillance program detected dysplasia or cancer in 16% (10 indefinite, 23 low-grade, and 4 high-grade dysplasias and 5 cancers). A finding of definite dysplasia or cancer was associated with age >45 years and increased symptoms. By life table analysis, the probability of detecting dysplasia or cancer after a negative screening colonoscopy was 22% by the fourth surveillance examination.

CONCLUSIONS

Colonoscopic surveillance should be strongly considered in chronic extensive Crohn's colitis.

Cancer risk in patients with inflammatory bowel disease: a population-based study

BACKGROUND

The objective of the current study was to determine the incidence of cancer among persons with inflammatory bowel disease (IBD) and to compare these incidence rates with those of the non-IBD population using population-based data from the administrative claims data of Manitoba's universal provincial insurance plan (Manitoba Health).

METHODS

IBD patients were matched 1:10 to randomly selected members of the population without IBD based on year, age, gender, and postal area of residence. The incidence of cancer was determined by linking records from the IBD and non-IBD cohorts with the comprehensive Cancer Care Manitoba registry. Incidence rates and rate ratios (IRR) were calculated based on person-years of follow-up (Crohn's disease = 21,340 person-years and ulcerative colitis [UC] = 19,665 person-years) for 1984-1997.

RESULTS

There was an increased IRR of colon carcinoma for both Crohn disease patients (2.64; 95% confidence interval [95% CI], 1.69-4.12) and UC patients (2.75; 95% CI, 1.91-3.97). There was an increased IRR of rectal carcinoma only among patients with UC (1.90; 95% CI, 1.05-3.43) and an increased IRR of carcinoma of the small intestine only in Crohn disease patients (17.4; 95% CI, 4.16-72.9). An increased IRR of extraintestinal tumors was observed only for the liver and biliary tract in both Crohn disease patients (5.22; 95% CI, 0.96-28.5) and UC patients (3.96; 95% CI, 1.05-14.9). There was an increased IRR of lymphoma for males with Crohn disease only (3.63; 95% CI, 1.53-8.62), and this finding did not appear to be related to use of immunomodulatory therapy. Compared with controls, Crohn's disease was associated with an increased risk of cancer overall, but UC was not.

CONCLUSIONS

There appear to be similar increased risks for developing colon carcinoma and hepatobiliary carcinoma among patients with Crohn disease and UC. There is an increased risk of developing rectal carcinoma in UC patients, an increased risk of developing carcinoma of the small bowel in Crohn disease patients, and an increased risk of developing lymphoma among males with Crohn disease.

Low mortality in ulcerative colitis and Crohn's disease in three regional centers in England

OBJECTIVES

Recent epidemiological studies suggest that mortality rates for inflammatory bowel disease (IBD) are similar to those of the general population. However, most of this work has been done in referred populations or larger urban centers. We intended to estimate mortality rates for ulcerative colitis (UC) and Crohn's disease (CD) in three British district general hospital practices in Wolverhampton, Salisbury, and Swindon.

METHODS

Consecutive patients with CD or UC were identified from 1978 to 1986 and followed prospectively. Demographic data, date and cause of death or health status at December 31, 1993 were used to estimate standardized mortality ratios (SMRs) and 95% confidence intervals.

RESULTS

Sixty-four deaths occurred in 552 patients (UC 41 of 356; CD 23 of 196). The overall SMRs were 103 [95% confidence interval (CI): 79-140] for UC and 94 (95% CI: 59-140) for CD. The respective SMRs were higher only in the first year after diagnosis at 223 (95% CI: 99-439; p = 0.02) and 229 (74-535; p = 0.056), and even then, most subjects died from non-IBD causes (5 of 13). Nonsurvivors were significantly older than survivors in both UC and CD (p < 0.01). The SMR was also significantly greater during a severe first attack of UC at 310 (95% CI: 84-793; p = 0.04). Patients with perianal or colonic CD had an increased SMR [396 (95% CI: 108-335; p = 0.02) and 164 (95% CI: 82-335; p = 0.02)] respectively, partly related to the older mean age (52 vs 32 yr, p < 0.001).

CONCLUSIONS

Mortality rates are not increased in IBD compared with the general population. However, older patients may be at increased risk of dying from other causes early in the disease clinical course.

A critical review of epidemiological studies in inflammatory bowel disease

This review addresses the difficulty in interpreting the results of epidemiological studies in IBD and in making meaningful comparisons between studies. Both ulcerative colitis and Crohn disease appear to be more common in some industrialized countries such as Scandinavia, United Kingdom, North America and less common in Central and Southern Europe, Asia and Africa. Given data showing an increased incidence of ulcerative colitis in the United Kingdom, it is crucial that more studies be conducted in developing countries. While the incidence of Crohn disease has increased strikingly in many areas, the incidence of ulcerative colitis has remained fairly stable in most. This could be due to the rising number of community-based studies, as well as the improved accuracy in diagnosing Crohn disease. Although, the incidence of IBD among Blacks in Africa is low, infection rates are high, life expectancy is lower than in developed countries. Data from the USA suggest that rates are similar in Afro-American and Caucasian populations. Rates for Jewish populations may be slightly higher than in non-Jewish populations but this also varies geographically. Careful attention to genetic, environmental, and socioeconomic factors must be accounted for in these studies. There is no strong evidence to support that IBD is more common in urban than in rural settings and migration towards more accessible health care has not been adequately addressed. Recent epidemiological studies suggest that mortality rates for IBD are similar to that of the general population for the majority of patients. However, older patients with IBD and newly diagnosed cases with severe diseases are at increased risk of dying. Epidemiological studies remain important in assisting with health policy planning and in hypothesis testing of etiological factors. As better diagnostic techniques become widely available and public health registries are increasingly used, it is possible that geographic differences will diminish. International collaborative studies will be better equipped to answer research questions addressing risk factors and disease natural history. We have summarized in Table V the essential criteria to conduct a sound epidemiological study, which would permit future testing of hypotheses among different populations.

Inflammatory bowel disease: epidemiology and management in an English general practice population

BACKGROUND

Inflammatory bowel diseases have significant long-term morbidity and healthcare resource consequences. Studies based on secondary care records may have underestimated the contribution of general practitioners (GPs) to its management.

AIMS

To describe the epidemiology and management of inflammatory bowel disease using GP records as the primary data source.

METHODS

A systematic search of GP clinical records in northern England, identifying cases of inflammatory bowel disease, patient consultation behaviour, prescribing patterns, and extent of specialist care.

RESULTS

In a population of 135 723, the incidence of ulcerative colitis was 13. 9/100 000 per year (CI: 7.5-20.3) and for Crohn's disease 8.3/100 000 per year (CI: 3.4-13.2). The age-sex adjusted point prevalence for ulcerative colitis on 1st January 1995 was 243.4/100 000 (CI: 217.4-269.4) and for Crohn's disease 144.8/100 000 (CI: 124.8-168.8). The mean number of consultations (s.d.) with specialists and GPs were similar, both in the first 12 months after referral (specialists 3.94 +/- 3.15, GPs 3.34 +/- 3.55) and in the most recent 12 months (1.02 +/- 2.02, 1.04 +/- 2.04). Only 29.9% of all patients were definitely under specialist care.

CONCLUSIONS

Prevalence rates, but not incidence rates, for inflammatory bowel disease are substantially higher than previously described in UK populations. General practitioners make a significant contribution to meeting the healthcare needs of these patients.

Update on inflammatory bowel disease genetics

The idiopathic inflammatory bowel diseases (IBD), comprised of Crohn's disease (CD) and ulcerative colitis (UC), are related, complex genetic disorders. With the completion of the human genomic sequence, identification of genetic variants contributing to IBD susceptibility can now more systematically be identified. Significant genetic linkages have been observed on chromosomes 16, 12, 14, 19, 6, and 1, of which the linkage to CD on chromosome 16 is the most well-established. For many of the other regions, evidence for linkage has been observed for both CD and UC. Candidate gene association studies have largely focused on genes involved in inflammatory pathways, such as cytokines and cytokine receptors. With greater understanding of genetic differences underlying both disease susceptibility and response to medical therapy, the individualization of medical approaches based on this knowledge may soon be possible in patients with IBD.

Crohn's disease in Japan: diagnostic criteria and epidemiology

New diagnostic criteria for Crohn's disease and a review of Japanese epidemiologic studies are presented. New diagnostic criteria for Crohn's disease were established by the Research Committee of Inflammatory Bowel Disease, set up by the Japanese Ministry of Health and Welfare. For a definite diagnosis one of the following three conditions is required: 1) longitudinal ulcer or luminal deformity induced by longitudinal ulcer or cobblestone pattern, 2) intestinal small aphthous ulcerations arranged in a longitudinal fashion for at least three months plus noncaseating granulomas, and 3) multiple small aphthous ulcerations in both the upper and lower digestive tract not necessarily with longitudinal arrangement, for at least three months, plus noncaseating granulomas. Moreover, ulcerative colitis, ischemic enterocolitis, and acute infectious enterocolitis should be excluded. Data from the Japanese Ministry of Health and Welfare, in addition to data collected from two study groups, these being the two largest studies in Japan, are reviewed with regard to epidemiology. The number of patients with Crohn's disease has increased remarkably. The prevalence and the annual incidence of patients with Crohn's disease in Japan were estimated to be approximately 2.9 and 0.6 per 10(5) population in 1986, respectively, and 13.5 and 1.2 per 10(5) population in 1998. Characteristic features of Crohn's disease in Japan are that the male-female ratio exceeds 2, and that there is no second peak of incidence in the age group of 55 to 65 years. Clinically, Crohn's disease with only multiple small aphthous ulcerations, which is the earliest stage of the disease that is diagnosable, was found in 5 percent of patients.

Does the failure to acquire helminthic parasites predispose to Crohn's disease?

Two polarized patterns (Th1 and Th2) of cytokines regulate inflammatory responses. Each cytokine pattern inhibits production of the opposing pattern. Lymphocytes from inflamed intestine due to Crohn's disease secrete a Th1 pattern of cytokines. Crohn's disease is most prevalent in highly industrialized countries with temperate climates. It occurs rarely in tropical third world countries with poor sanitation. We propose that exposure to an environmental agent predisposes individuals to Crohn's disease. Parasitic worms (helminths) are common in tropical climates and in populations subject to crowding and poor sanitation. Children are most subject to helminthic colonization. Many helminths live within or migrate through the human gut where they interact with the mucosal immune system. The host mounts a mucosal response that includes Th2 cytokine production limiting helminthic colonization. Helminths and their eggs probably are the most potent stimulators of mucosal Th2 responses. The Th2 response provoked by parasitic worms can modulate immune reactions to unrelated parasitic, bacterial, and viral infections. Many people in developed countries now live in increasingly hygienic environments, avoiding exposure to helminths. Perhaps failure to acquire these parasites and experience mucosal Th2 conditioning predisposes to Crohn's disease, which is an overly active Th1 inflammation.

Concurrence of inflammatory bowel disease and multiple sclerosis

OBJECTIVES

To quantify the coexistence of inflammatory bowel disease (IBD) and multiple sclerosis (MS) and to characterize the diseases when they coexist.

PATIENTS AND METHODS

In this retrospective study of medical records spanning 1950 through 1995, the diagnoses of Crohn disease (CD), ulcerative colitis (UC), and MS were based on review of inpatient and outpatient records by a gastroenterologist and a neurologist.

RESULTS

We identified 4 residents of Olmsted County, Minnesota, with IBD (3 UC, 1 CD) who had concurrent, clinically definite MS; all had mild neurologic disease with little disability. These comprised 1% of the IBD and 1.8% of the MS cohort. The CD patient had undergone terminal ileal resection; of the UC patients, 2 had pancolitis, and 1 had proctosigmoiditis. The observed prevalence of MS at onset of IBD was 3.7 times the expected (95% confidence interval, 0.8-10.8). We also reviewed the records of 32 referral patients with both diagnoses. Disability from MS was moderate at median follow-up of 8.5 years. By 15 years, ambulation was impaired in most patients. Neurologic disability was similar between patients with CD and UC.

CONCLUSIONS

Concurrence of the 2 diseases was greater than expected. Although MS and IBD may share common predisposing factors, not enough information is available to speculate about possible mechanisms.

Early measles virus infection is associated with the development of inflammatory bowel disease

OBJECTIVE

The measles virus has been implicated as a possible etiological agent in the development of inflammatory bowel disease (IBD). Measles infection at an early age is associated with subacute sclerosing panencephalitis, a degenerative neurological condition caused by persistent measles infection of the central nervous system. We sought to determine whether infection with measles virus at an early age was also associated with an increased risk of developing IBD.

METHODS

Patients with measles infection diagnosed before the age of 5 yr were identified through the diagnostic indices of the Mayo Clinic and the Rochester Epidemiology Project. A questionnaire was used to ascertain a subsequent history of IBD, which was confirmed by records from the subjects' physicians. The risks of developing Crohn's disease and ulcerative colitis were calculated relative to expected rates for these conditions in the Olmsted County, Minnesota population.

RESULTS

Of 1164 eligible cases, 662 (57%) completed the questionnaire. There were six confirmed cases of Crohn's disease and six of ulcerative colitis. The expected number of cases was 1.9 for Crohn's disease (standardized incidence ratio [SIR] 3.1, 95% confidence interval [CI] 1.1-6.8) and 2.0 for ulcerative colitis (SIR 3.0, CI 1.1-6.5). There was a trend towards a higher risk of developing IBD with an earlier age of infection.

CONCLUSIONS

Early measles infection is associated with an increased risk of developing Crohn's disease and ulcerative colitis. The risk may be higher with earlier infection.

Risk of cancer in inflammatory bowel disease (IBD)

Patients with inflammmatory bowel disease (IBD) have been reported to have an increased risk of colorectal cancer. Yet, the quantitation of the risk varies widely from one study to the next. This is most likely due to biases in the assessment of cancer risk in IBD, namely, a relatively low prevalence of IBD-related cancer and the clinically heterogeneous nature of IBD in the population. Total proctocolectomy also changes the natural history of IBD-related cancer. Ulcerative colitis (UC)-related cancer is more probable in total and extensive colitis and occurs approximately a decade after diagnosis. Crohn's disease-related colorectal cancer is reported in many, but not all, studies, and the relative risk differs between hospital- and population-based studies. IBD-related cancer is relatively uncommon in childhood; however, this is also a subject of debate. There are no data on the incidence of IBD-related cancer in Europe as a whole; there are only separate studies. A reduced risk for UC-related cancer in patients treated with anti-inflammatory drugs has been reported. The two main strategies for preventing IBD-related cancer are prophylactic colectomy and colonoscopic surveillance. To date, there have virtually been no cost-effectiveness analyses and no studies regarding total disease outcome or patient's quality of life with either strategy. No controlled, prospective trials have been reported in the literature. UC patients with familiar predisposition for colorectal cancer and with concomitant primary sclerosing cholangitis are groups at high risk for IBD-related cancer. Cancer risk in IBD has to be reinvestigated and properly estimated with population-based studies in several areas with standard methods already described.

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.

The cost of hospitalization in Crohn's disease

OBJECTIVE

The aim of this study was to evaluate the demographics, resource use, and costs associated with hospitalization of Crohn's disease patients.

METHODS

All patients hospitalized at our institution from 7/1/96 to 6/30/97 with a primary diagnosis of "Crohn's Disease" were analyzed using a computerized database. Data are presented "per hospitalization."

RESULTS

A total of 175 hospitalizations (147 patients) were identified. Mean patient age was 36.5 yr; 61% were female; 82% Caucasian. Payer mix was most commonly contracted (57%), commercial (21%), or Medicare (13%). 57% of hospitalizations had a primary surgical procedure; the remainder were medical. Average length of stay was 8.7 days (surgical, 9.6 days; medical, 7.5 days). The average cost of hospitalization, excluding physician fees, was $12,528 (surgical, $14,409; medical, $10,020), whereas average charges were $35,378 (surgical, $46,354; medical, $20,744), including physician fees, which averaged $7,249 (surgical, $11,217; medical, $1,959). Mean reimbursements were $21,968 (surgical, $28,946; medical, $12,666) with average weighted reimbursement rates of 60.17% of hospital charges, 69.57% of physician fees. The distribution of costs across subcategories was: Surgery (39.6%), Pharmacy (18.6%), Laboratory (3.8%), Radiology (2.1%), Pathology (0.8%), Endoscopy (0.3%), and Other Hospital Costs (34.9%). Of the hospitalizations, 87% included treatment with steroids, 23% with immunomodulators, and 14% with aminosalicylates; 27% included the administration of total parenteral nutrition, which accounted for 63% of the total pharmacy costs.

CONCLUSIONS

Surgery accounts for the majority of hospitalizations, nearly 40% of their total costs, and 75% of overall charges and reimbursements. Therapy that decreases the number of surgical hospitalizations should substantially reduce inpatient Crohn's disease costs, as well as overall costs.

Genetic aspects of inflammatory bowel disease: how far have we come, and where are we heading?

Crohn"s disease and ulcerative colitis are related complex genetic disorders, with gene-gene and gene-environment interactions that are critical to their pathogenesis. Multiple genetic loci have been implicated through genome-wide searches. Of these, a locus on Crohn"s disease has been definitively established in the pericentromeric region of chromosome 16. Multiple candidate gene studies have been forwarded, and functionally significant variants in immune-associated genes will provide additional insight. Characterization of the genetic variation responsible for causing inflammatory bowel disease will result in development of novel therapeutic approaches as well as in tailoring of specific therapies to individual patients based on their specific molecular pathogenesis.

Commonalities in the time trends of Crohn's disease and ulcerative colitis

OBJECTIVE

The analysis of the time trends of inflammatory bowel disease (IBD) is a powerful research tool to assess the contribution of environmental factors to its etiology and to gain insights about possible causative mechanisms. A previous study revealed a characteristic relationship between the time trends of mortality from Crohn's disease and ulcerative colitis. The present study aimed to test whether the most recent temporal patterns still corroborate the hypothesis of two interacting risk factors in the development of IBD. The time trends of IBD from six countries were checked for common features.

METHODS

Mortality data from Australia, Canada, England and Wales, the Netherlands, Sweden, and the United States were analyzed. Age- and sex-specific death rates, as well as total death rates, from Crohn's disease and ulcerative colitis were plotted against the period of death.

RESULTS

Mortality from ulcerative colitis decreased continuously during the past 40 years. Mortality from Crohn's disease increased between 1950 and the mid-1970's until reaching a similar level as mortality from ulcerative colitis. Since then the death rates of both diseases have followed a parallel time course. A similar behavior was found, if male and female data were analyzed separately. It could be also discerned in the time trends of each age group. The data from all six countries revealed identical temporal patterns.

CONCLUSIONS

The similar time trends of IBD from different countries support the hypothesis that identical causative mechanisms are responsible for the mortality and the occurrence of IBD among populations characterized by different political history and health care systems. The rapidity of the temporal changes implicates environmental agents in the etiology of both diseases. The relationships between the temporal changes of Crohn's disease and ulcerative colitis point at the existence of a shared risk factor responsible for the occurrence of both diseases, and at the existence of at least one additional factor, responsible for the expression of Crohn's disease alone.

Clinical course and costs of care for Crohn's disease: Markov model analysis of a population-based cohort

BACKGROUND & AIMS

Crohn's disease results in substantial morbidity and high use of health services. The aim of this study was to describe the lifetime clinical course and costs of Crohn's disease in a 24-year population-based inception cohort of patients with Crohn's disease in Olmsted County, Minnesota.

METHODS

Disease states were defined by medical and surgical treatment. A Markov model analysis calculated time in each disease state and present value of excess lifetime costs in comparison with an age- and sex-matched cohort.

RESULTS

For a representative patient, projected lifetime costs were $39,906 per patient using median charges and $125,404 using mean charges. There were 29.1 years (63% of total) without medications. There were 12.7 years (27%) on aminosalicylate therapy, generating $11,467 (29%) in charges, and 3.2 years (7%) on corticosteroid or immunosuppressive therapy, generating $5147 (13%) in charges. Surgery generated $17,526 (44%) in charges.

CONCLUSIONS

Most of the clinical course is spent in remission, either medical or surgical. Aminosalicylate therapy accounts for 29% of the costs of care. Surgery has the highest charges but the longest remissions. Treatment strategies that induce remission in mild disease and maintain remission with lower-cost maintenance therapy will have the largest effect on patient outcomes and costs.

[Initial symptoms, extra-intestinal manifestations and course of pregnancy in chronic inflammatory bowel diseases]

BACKGROUND

In many cases inflammatory bowel disease is accompanied by extraintestinal manifestations. This results in lowering of live quality. The aim of this study was to gather data retrospectively about initial symptoms, extraintestinal manifestations and course of pregnancy in a large unselected population with inflammatory bowel disease in South Germany.

PATIENTS AND METHODS

Data from 1975 to 1989 (392 patients) were analyzed and partially compared with data from 1992 to 1995 (211 patients).

RESULTS

Patients with Crohn's disease in average have been 25 years old at the time point of initial symptoms, whereas the age of ulcerative colitis patients was 30 years (p < 0.0001). The number of Crohn's disease patients with a long interval between initial symptoms and diagnosis (> 1 year) was significantly decreased in the second population (50% vs 38%; p < 0.05). Dominant initial symptoms in Crohn's disease were indisposition, abdominal pain and nonbloody diarrhea in contrast to ulcerative colitis which manifested mostly with bloody diarrhea. Extraintestinal manifestations occurred in 76% of patients with Crohn's disease and 64.6% with ulcerative colitis. Complications during the course of pregnancy have been detected in 40.5% in Crohn's disease and 60% in ulcerative colitis.

CONCLUSION

A better knowledge of initial symptoms and extraintestinal manifestations in inflammatory bowel disease can help to decrease the interval between initial symptoms and the diagnosis. Pregnancy in patients with inflammatory bowel disease needs to be treated with special care.

Identification of novel susceptibility loci for inflammatory bowel disease on chromosomes 1p, 3q, and 4q: evidence for epistasis between 1p and IBD1

The idiopathic inflammatory bowel diseases, Crohn's disease (CD) and ulcerative colitis (UC), are chronic, frequently disabling diseases of the intestines. Segregation analyses, twin concordance, and ethnic differences in familial risks have established that CD and UC are complex, non-Mendelian, related genetic disorders. We performed a genome-wide screen using 377 autosomal markers, on 297 CD, UC, or mixed relative pairs from 174 families, 37% Ashkenazim. We observed evidence for linkage at 3q for all families (multipoint logarithm of the odds score (MLod) = 2.29, P = 5.7 x 10(-4)), with greatest significance for non-Ashkenazim Caucasians (MLod = 3.39, P = 3.92 x 10(-5)), and at chromosome 1p (MLod = 2.65, P = 2.4 x 10(-4)) for all families. In a limited subset of mixed families (containing one member with CD and another with UC), evidence for linkage was observed on chromosome 4q (MLod = 2.76, P = 1.9 x 10(-4)), especially among Ashkenazim. There was confirmatory evidence for a CD locus, overlapping IBD1, in the pericentromeric region of chromosome 16 (MLod = 1.69, P = 2.6 x 10(-3)), particularly among Ashkenazim (MLod = 1.51, P = 7.8 x 10(-3)); however, positive MLod scores were observed over a very broad region of chromosome 16. Furthermore, evidence for epistasis between IBD1 and chromosome 1p was observed. Thirteen additional loci demonstrated nominal (MLod > 1.0, P < 0.016) evidence for linkage. This screen provides strong evidence that there are several major susceptibility loci contributing to the genetic risk for CD and UC.

Crohn's disease in Olmsted County, Minnesota, 1940-1993: incidence, prevalence, and survival

BACKGROUND & AIMS

Many centers worldwide have reported an increased incidence of Crohn's disease, but population-based data in North America are sparse. We studied the incidence and prevalence of Crohn's disease in Olmsted County, Minnesota, and examined temporal trends in incidence and survival.

METHODS

Residents diagnosed with Crohn's disease between 1970 and 1993 were incidence cases, and residents with Crohn's disease who were alive on January 1, 1991, were prevalence cases. Cases from previous studies were reconfirmed. Rates were adjusted using 1990 U.S. Census figures for whites. Incidence trends were evaluated with a Poisson regression model. Survival from diagnosis was compared with that expected for U.S. north-central whites.

RESULTS

Between 1940 and 1993, 225 incidence cases were identified, for an adjusted incidence rate of 5.8 per 100,000 person-years. On January 1, 1991, there were 145 residents with Crohn's disease, an adjusted prevalence rate of 133 per 100,000, 46% higher than that seen in 1980. Incidence rates before 1964 were significantly lower than those of 1989-1993. Observed survival was less than expected (P = 0.007).

CONCLUSIONS

The incidence of Crohn's disease has stabilized since the 1970s at a rate higher than that seen previously. Prevalence has increased by 46% since 1980. Overall survival is slightly decreased.

Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States

OBJECTIVE

To provide a single source for the best available estimates of the national prevalence of arthritis in general and of selected musculoskeletal disorders (osteoarthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, the spondylarthropathies, systemic lupus erythematosus, scleroderma, polymyalgia rheumatica/giant cell arteritis, gout, fibromyalgia, and low back pain).

METHODS

The National Arthritis Data Workgroup reviewed data from available surveys, such as the National Health and Nutrition Examination Survey series. For overall national estimates, we used surveys based on representative samples. Because data based on national population samples are unavailable for most specific musculoskeletal conditions, we derived data from various smaller survey samples from defined populations. Prevalence estimates from these surveys were linked to 1990 US Bureau of the Census population data to calculate national estimates. We also estimated the expected frequency of arthritis in the year 2020.

RESULTS

Current national estimates are provided, with important caveats regarding their interpretation, for self-reported arthritis and selected conditions. An estimated 15% (40 million) of Americans had some form of arthritis in 1995. By the year 2020, an estimated 18.2% (59.4 million) will be affected.

CONCLUSION

Given the limitations of the data on which they are based, this report provides the best available prevalence estimates for arthritis and other rheumatic conditions overall, and for selected musculoskeletal disorders, in the US population.

Incidence of Crohn's disease in Stockholm County 1955-1989

AIM

To evaluate the incidence of Crohn's disease in Stockholm County between 1955 and 1989.

METHODS

A cohort of 1936 patients with Crohn's disease was retrospectively assembled. Incidence rates and changes in disease distribution were assessed.

RESULTS

The mean increase in incidence was 15% (95% confidence intervals 12% to 18%) per five year period with a mean annual incidence rate at 4.6/10(5) during the last two decades. The mean incidence for the entire study period was similar for men and women. The mean age at diagnosis increased from 25 years in 1960-64 to 32 years in 1985-89, partly because of an increasing proportion of patients aged at least 60 years at diagnosis. The proportion of patients with colonic Crohn's disease at the time of diagnosis increased from 15% to 32% (17% difference; 95% confidence intervals 12% to 23%) whereas the proportion of patients with ileocaecal disease decreased from 58% to 41% (17% difference; 95% confidence intervals 10% to 24%) during the study period. Elderly patients had a higher proportion of small bowel disease and a lower proportion of ileocolonic disease compared with the younger patients.

CONCLUSION

The incidence rate of Crohn's disease in Stockholm has stabilised at 4.6/10(5) and the proportion of elderly patients has increased during a 35 year period. Colonic Crohn's disease has increased in frequency with a reciprocal decrease in ileocaecal disease.

Colorectal adenocarcinoma in Crohn's disease: a retrospective histologic study

PURPOSE

The aim of this study was to review all histopathologic sections from surgical specimens with inflammatory bowel disease and colorectal carcinoma filed at this hospital between 1951 and 1996.

METHOD

A total of 40 surgical (n = 39) or autopsy (n = 1) colon or colorectal specimens were reviewed. Internationally accepted histologic criteria were strictly applied to differentiate Crohn's disease (CD), ulcerative colitis (UC), and indeterminate colitis (IC).

RESULTS

Of the 40 specimens with inflammatory bowel disease and carcinoma, 22 (55 percent) had CD, 16 (40 percent) had UC, and the remaining 2 (5 percent) had IC. Males accounted for 72.7 percent or 16 of the 22 patients with colorectal carcinoma in CD and for 68.7 percent or 11 of the 16 patients with carcinoma in UC. Both patients with IC and carcinoma were males. The median age of patients at diagnosis was as follows: CD, 20 (range, 7-68) years; UC, 23 (range, 5-21) years. In IC, the age was 61 and 81 years, respectively. The median disease duration (before detection of colorectal cancer) was as follows: CD, 18.5 (range, 1-45) years; UC, 19 (range, 6-38) years. For cases with IC, it was 13 and 19 years, respectively. Median age of patients at cancer diagnosis was as follows: CD, 48 (range, 21-78) years; UC, 49 (range, 21-81) years. Ages at cancer diagnosis in IC were 68 and 81 years. Colorectal carcinoma tend to develop among relatively young patients with CD and UC. Mucinous adenocarcinomas accounted for approximately one-third of the carcinomas affecting CD. Thirty percent of old specimens (before the end of 1982) had in fact carcinoma complicating CD and not UC (the latter being the diagnosis appearing in old pathologic reports). During a time lapse of 38 years (i.e., between 1951 and 1989), only 11 cases of colorectal CD with carcinoma (i.e., 0.2 cases/year) were found, but as many as 11 during the past 6.5 years (i.e., 1.7 cases/year) have been diagnosed. Only 42.3 percent (11/26) of cases with colorectal inflammatory bowel disease and carcinoma operated on between 1951 and the end of 1989 had Crohn's colitis but as many as 78.6 percent (11/14) of those operated on between 1990 and May 1996 had Crohn's colitis. Review of the literature indicated that 64.8 percent or 191 of the 295 cases of colorectal carcinomas in CD so far reported occurred in the past 6.5 years. It would seem as if the risk of colorectal carcinoma in Crohn's colitis has increased in later years.

CONCLUSIONS

1) Reports on cancer frequency in UC based on old histopathologic records should be subjected to critical histologic re-evaluation; 2) carcinoma in Crohn's colitis has increased at this hospital, particularly since 1990; 3) the surveillance program strategy used in patients with long-standing UC at this hospital should also embrace patients with Crohn's colitis.

Review article: insurance risks for patients with ulcerative colitis or Crohn's disease

Prospective population-based studies have allowed a re-evaluation of the risks of insuring patients with ulcerative colitis or Crohn's disease. Life expectancy, the risk of cancer and working capacity are very much better than previously recognised and are normal for many patients. Three population-based studies in ulcerative colitis have shown a mortality similar to or slightly less than the general population except in the first year after diagnosis, whilst two have shown a slightly higher mortality (standardized mortality ratio, SMR = 1.4), except for those with proctitis. In Crohn's disease, two population-based studies have also shown an increased mortality (SMR = 1.4), which is similar to that of unskilled manual labourers (SMR = 1.43) from all causes of death. Three other studies have shown no increase in overall mortality, except in the first 5 years after diagnosis, in those with proximal small intestinal disease and in some patients needing multiple operations. Insurance risks should be evaluated on an individual basis, after details of the extent and pattern of disease have been obtained. Although the 'standard life' in insurance terms differs from that of the general population, because people who seek life assurance are self-selected from a more affluent section of society, many patients can be identified who have a particularly good prognosis. These include patients with ulcerative proctitis, those with left-sided colitis in extended remission (> 12 months), and patients more than 30 years old with localized ileal or ileocaecal Crohn's disease that has responded to treatment. From the published data, it is difficult to justify increasing the insurance premium in such patients.

A population-based study of inflammatory bowel disease in Florence over 15 years (1978-92)

BACKGROUND

In the group of inflammatory bowel disease (IBD), ulcerative colitis (UC) and Crohn's disease (CD) are considered to be more frequent in Western countries and in areas with a high socioeconomic development but relatively infrequent in southern Europe. Sporadic reports have indicated a lower incidence and a milder course of the disease in Mediterranean countries. Although conclusive data on this point are still lacking, recent reports suggest an increase in both incidence and prevalence rates.

METHODS

The incidence of UC and CD during the period January 1978 to December 1992 and their prevalence on 31 December 1992 were estimated in the 15-year-old population of the metropolitan area of Florence. Clinical, demographic, and follow-up information was collected for all identified IBD patients.

RESULTS

A total of 796 residents (345 females and 454 males) were newly diagnosed as having IBD during the study period. Of these 593 had UC and 203 CD. The age-standardized incidence rates, calculated for each of five 3-year consecutive periods, rose from 3.8 (in 1978-80) to 9.6 per 100,000 person-years (in 1990-92) for UC and from 1.9 (in 1978-80) to 3.4 (in 1990-92) for CD. Both trends were statistically significant. The prevalence estimated on 31 December 1992 was 121.0 and 40.0 per 100,000 inhabitants for UC and CD, respectively.

CONCLUSIONS

Our results confirm that IBD incidence rates and prevalence in this area of central Italy are currently comparable with those reported in northern Europe. These data are necessary for planning adequate health care services for IBD patients.

Concomitant active Crohn's disease and the acquired immunodeficiency syndrome

Symptomatic human immunodeficiency virus (HIV) infection is accompanied by depressed CD4+ T-lymphocyte counts. These cells seem to play a role in the inflammatory processes in Crohn's disease. It has even been speculated that depression of CD4+ T-lymphocytes in HIV infection may cure Crohn's disease. Here we describe a 41-year-old drug-addicted man with a 9-year history of Crohn's disease. HIV infection was diagnosed 8 years ago. At present he has stage-C3 HIV infection. He was admitted because of weight loss and chronic diarrhea with rectal blood and mucus discharge. Crohn's disease was confirmed endoscopically and histologically. Infectious diarrhea known to mimic Crohn's disease in patients with acquired immunodeficiency syndrome (AIDS) was excluded. In summary, we describe a patient with AIDS (CD4 count, 84/microliter) and active Crohn's disease, showing that both illnesses can occur simultaneously.

A prospective epidemiologic study of Crohn's disease in Heraklion, Crete. Incidence over a 5-year period

BACKGROUND

There has been an impression from published work that Crohn's disease is less common in southern than in northern Europe. A low incidence of Crohn's disease has been observed in Greece, but conclusive data are still lacking.

METHOD

A 5-year prospective and population-based epidemiologic study of Crohn's disease was carried out in a well-defined area of Crete.

RESULTS

The mean annual incidence of the disease for the years 1990-94 was 3.0 per 10(5) inhabitants. During the study period the incidence increased from 1.9/10(5) in 1990 to 3.8/10(5) in 1994. The male to female ratio was 2.4:1. The age group 25-34 years had the highest age-adjusted incidence (6.3/10(5)). The incidence of Crohn's disease was also found to be higher in smokers, in urban areas, and in people with high educational level.

CONCLUSION

Crohn's disease is common in Heraklion, Crete. The findings of the study are discussed in relation to those of other European countries.

Epidemiology of inflammatory bowel disease: an update

What have epidemiologic studies on IBD taught so far? Consistent findings are as follows: A high incidence of both CD and UC in industrialized countries and an increase in these areas of the incidence of CD during the years 1960-80 followed by a plateau phase, and a more stable pattern in UC during the same period have been found. A greater number of mild cases have probably been diagnosed recently. This also helps to explain the differences in severity and survival between community and referral centre groups. The male to female ratio is greater than 1 in UC, and this is the opposite in CD. Mortality of IBD has decreased during the past decades. As young people are especially prone to develop IBD, most of those affected will have their disease for many years. In developing IBD, genetic influences are of importance. However, epidemiologic studies strongly point to possible interactions between genetically determined features and environmental or other factors. Of these exogenic factors smoking is the most consistent, being of negative influence in CD and protective in UC. Diet and oral contraceptives may influence disease expression, and perinatal events such as viral infections may alter adult susceptibility. The question remains open whether UC and CD are one diseases entity. Similarities in the epidemiologic features of UC and CD support the idea of IBD being one disease. Other findings suggest dividing UC and CD into further subgroups: in CD it has been suggested that fibrostenotic, penetrating, and inflammatory behaviour should be considered different disease entities; in UC some groups consider ulcerative proctitis a disease entity on its own, separating it from the proximally extending colitis. In therapeutic trials this approach has proved to be of importance, and it is not inconceivable that in subgroups, with regard to aetiopathogenetic mechanisms, different factors have to be looked for.

Colorectal adenocarcinoma in Crohn's disease

OBJECTIVE

The authors' aim was to review the clinical features and estimate the long-term survival of patients with colorectal carcinoma complicating Crohn's disease.

SUMMARY BACKGROUND DATA

Recent studies have demonstrated a significantly increased risk of colorectal carcinoma in patients with Crohns disease.

METHODS

The authors reviewed retrospectively the medical records of 30 patients with Crohn's disease admitted to The Mount Sinai Hospital between 1960 and 1989 in whom colorectal adenocarcinoma developed. All patients were operated on and follow-up was complete for all patients to 10 years after operation, to the time of death, or to the closing date of the study in December 1989.

RESULTS

The 30 patients in the series had 33 colorectal adenocarcinomas; three patients (10%) presented with two synchronous cancers. The patients were relatively young (mean age, 53 years) and had long-standing Crohn's disease (duration >20 years in 87%). The 5-year actuarial survival was 44% for the overall series: 100% for stage A, 86% for stage B, 60% for stage C. All five patients with excluded bowel tumor died of large bowel cancer within 2.4 years; by contrast, the actuarial 5-year survival for patients with in-continuity tumors was 56%.

CONCLUSIONS

The incidence, characteristics, and prognosis of colorectal carcinoma complicating Crohn's disease are similar to the features of cancer in ulcerative colitis, including young age, multiple neoplasms, long duration of disease, and greater than a 50% 5-year survival rate (without excluded loops). These observations suggest the advisability of surveillance programs for Crohn's disease of the colon similar to those for ulcerative colitis of comparable duration and extent.

Prevalence of Crohn's disease and simultaneous occurrence of extraintestinal complications and cancer. An epidemiologic study in adults

BACKGROUND

Very dissimilar prevalence figures for Crohn's disease (CD) have been reported from different regions of Scandinavia. There are few reports on the occurrence of liver, joint, skin, and eye disease and gastrointestinal cancer in CD.

METHODS

All patients > or = 16 years old with CD living in a well-defined catchment area on 1 March 1990 were identified from the previous 10 years' registers of inpatients and outpatients. The records were screened for evidence of extraintestinal complications and fistulas.

RESULTS

The prevalence of CD was 94/10(5) (95% confidence interval, 84-104) inhabitants > or = 16 years old. Signs of liver disease were encountered in 1 of 10 patients, and other extraintestinal complications and intestinal cancer occurred in 1-3%. The true prevalence of primary sclerosing cholangitis could not be assessed.

CONCLUSION

The prevalence of CD was midway between recent figures from Orebro and Copenhagen. Fistulas and pathologic liver laboratory test results were more prevalent when CD involved both the large and small bowel.

Crohn's disease and cancer: a population-based cohort study

BACKGROUND/AIMS

To study the association between Crohn's disease and cancer, we performed a population-based study of 1251 subjects with Crohn's disease diagnosed in Stockholm from 1955 to 1984 and followed in both the National Cancer Register and the National Cause-of-Death Register until 1989.

METHODS

For comparisons, regional cancer incidence rates in Stockholm County were used together with individually computed person-years at risk in the Crohn's disease cohort.

RESULTS

Overall, 69 malignancies occurred among 67 individuals as compared with 59.80 expected malignancies (standardized morbidity ratio [SMR] = 1.15; 95% confidence interval, 0.90-1.46). An excess number of cancers of the upper gastrointestinal tract (SMR, 3.05; 95% confidence interval, 1.67-5.11) was observed, mainly because of an increased number of cancers of the small intestine (SMR, 15.64; 95% confidence interval, 4.26-40.06). An increased occurrence of urinary bladder cancer was also observed (SMR, 2.68; 95% confidence interval, 1.08-5.53).

CONCLUSIONS

The occurrence of colorectal cancer was not increased.

Ulcerative colitis and Crohn's disease: a comparison of the colorectal cancer risk in extensive colitis

The risk of developing colorectal cancer has been compared in two identically selected cohorts of patients with extensive Crohn's colitis (n = 125) and extensive ulcerative colitis (n = 486). In both groups the effects of selection bias have been reduced wherever possible. There was an 18-fold increase in the risk of developing colorectal cancer in extensive Crohn's colitis and a 19-fold increase in risk in extensive ulcerative colitis when compared with the general population, matched for age, sex, and years at risk. The absolute cumulative frequency of risk for developing colorectal cancer in extensive colitis was 8% at 22 years from onset of symptoms in the Crohn's disease group and 7% at 20 years from onset in the ulcerative colitis group. The relative risk of colorectal cancer was increased in both ulcerative colitis and Crohn's disease among those patients whose colitis started before the age of 25 years. Whether the absolute risk is greater in the younger age group or merely reflects that the expected number of carcinomas increases with age is uncertain. While there is an increased risk of developing colorectal cancer in extensive colitis the number of patients with Crohn's disease who actually develop colorectal cancer is small because many patients with extensive Crohn's colitis undergo colectomy early in the course of their disease to relieve persistent symptoms unresponsive to medical treatment.

Incidence of inflammatory bowel disease in northern France (1988-1990)

There were no data concerning the incidence of inflammatory bowel disease (IBD) in France. The aim of this study was to investigate the incidence of Crohn's disease and ulcerative colitis in northern France. This prospective population based study was realised through the gastroenterologists of the region Nord-Pas de Calais and the Somme Department. Each gastroenterologist referred patients consulting for the first time with clinical symptoms compatible with IBD. Data were collected by an interviewer practitioner present at the gastroenterologist's consulting room. Two independent expert gastroenterologists assessed each case in a blind manner and made a final diagnosis of Crohn's disease, ulcerative colitis, ulcerative proctitis, or unclassifiable chronic colitis. From 1988 to 1990, 1291 cases of IBD were recorded: 674 (52%) Crohn's disease, 466 (36%) ulcerative colitis including 162 proctitis (35%), and 151 (12%) unclassifiable chronic colitis. The mean annual incidence was 4.9 per 100,000 for Crohn's disease and 3.2 for ulcerative colitis. The sex ratio F/M was 1.3 for Crohn's disease and 0.8 for ulcerative colitis. The highest age specific incidence rate for Crohn's disease was between 20 and 29 years: 13.1 for women and 9.8 for men. The highest age specific incidence rate for ulcerative colitis was between 20 and 39 years: 5.5 for women and 6.5 for men. This first French prospective study has shown an incidence rate for Crohn's disease comparable with that seen in north European studies but lower than that seen for ulcerative colitis. These results could be related to the different environmental factors or the genetic background of the population studied, or both.

Clinical course and long-term prognosis of Crohn's disease in Japan

The long-term outcome of Crohn's disease was reviewed in 74 patients who had a history of more than 10 years (range 10.8-27.3) since disease onset. The observation period was between 4.3 and 18.5 years, the mean and SD being 10.6 +/- 3.1 years. The means and SD of age at onset and final observation were 21 +/- 7 and 37 +/- 8 years, respectively. Fifty-eight of the 74 patients had not undergone bowel resection at the time of diagnosis; of these 58, 31 (53.4%) had an operation for the disease during the follow-up period. Thus, of the 74 patients, 47 (63.5%) (these 31, plus the 16 who had undergone bowel resection at the time of diagnosis) had an operation at least once during a follow-up period of 10 years or more. The cumulative operation rates 5, 10, and 15 years after onset in the 74 and 58 patients above were 18.9%, 6.9%, and 40.8%, and 34.8%, 49.1%, and 46.0%, respectively. The corresponding figures 5 and 10 years after diagnosis in all 74 patients and the 58 patients were 32.3% and 28.6% and 47.3% and 46.3%, respectively. There were no significant differences in the incidence of operation rate in relation to anatomical involvement. Cumulative reoperation rates 1, 3, 5, and 10 years after the first operation in the 31 patients who were operated on during the follow-up period were 3.4%, 6.9%, 25.5%, and 51.7%, respectively. Three patients died, the causes of death in one being directly related to Crohn's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Crohn's disease and colorectal cancer

The colorectal cancer risk in Crohn's disease eliminating all known biases was assessed in a cohort of 281 patients with Crohn's disease who resided in the West Midlands at the time of diagnosis, and were first seen within five years of onset of symptoms between 1945-1975. All patients were 15 years of age or more at onset and were followed up from 12-35 years (total 5213 person years at risk (PYR)). The colorectal cancer risk in the series compared with the risk in the general population was computed by applying sex and age specific PYRs to the date of death or end of the study period 31 December 1991. There were six colonic and two rectal cancers. Six of the eight colorectal cancers were diagnosed 20 or more years after the onset of Crohn's disease. The relative risk (RR) of colorectal cancer for the series as a whole was 3.4 (p < 0.001), with a fivefold excess in the colon, but no significant excess in the rectum. Patients with extensive colitis showed an 18-fold increase in risk (RR = 18.2, p < 0.001), which decreased with increasing age at onset. This study shows that there is a statistical excess risk of developing colorectal cancer in patients who develop their Crohn's disease at a young age of onset (less than 30 years of age).