Incidence Rates Of Inflammatory Bowel Disease Research Articles

Inflammatory Bowel Disease in South Limburg (the Netherlands) 1991–2002: Incidence, diagnostic delay, and seasonal variations in onset of symptoms

Background and aims Increasing incidence in Inflammatory Bowel Disease (IBD) has been suggested. Recent data on population based incidence rates within Europe are however scarce. Primary aim was to investigate prospectively the incidence of IBD within a well-defined geographical and administrative area of the Netherlands, the South Limburg IBD registry. Secondary aims were to study the duration of symptoms before diagnosis (lag time) and seasonal influences on the incidence of IBD. Methods The incidence was examined using standardized registration of all newly diagnosed IBD patients, between 1–1–1991 and 1–1–2003. Medical records were reviewed to verify the diagnosis. At inclusion, diagnostic lag time was registered in months. Results Age standardized incidence rates per 100,000 person-years (p-y) were: Crohn's Disease, male 4.84, female 7.58; Ulcerative Colitis, male 8.51, female 6.92; and Indeterminate Colitis, male 1.05, female 0.93. Incidence rates did not significantly changes over time in either Crohn's Disease, Ulcerative Colitis or Indeterminate Colitis. Lag time was 5 (0–360) months in Crohn's Disease, 3.0 (0–480) months in Ulcerative Colitis and 3.0 (0–180) months in Indeterminate Colitis. Lag time was not significantly different between the periods 1991–1993 and 2000–2002, and no statistical differences in the onset of symptoms per calendar month or season were found. Conclusions Our results, from the South Limburg region (the Netherlands), show no significant change in incidence rates of IBD. The incidence found is relatively high compared to other European countries. Lag time did not change during the study period, and seasonal influence of incidence rates could not be confirmed.

A characterization in childhood inflammatory bowel disease, a new population-based inception cohort from South-Eastern Norway, 2005–07, showing increased incidence in Crohn's disease

Objective. Owing to rising incidence rates in inflammatory bowel disease (IBD), there has been increased interest in causal relationships in pediatric disease. The present population-based inception cohort was recruited in the Oslo area from 2005 to 2007, with the aim of conducting a detailed characterization of treatment-naïve patients at diagnosis. Material and methods. After an invitation was extended to all general practitioners in the catchment area, patients aged <18 years with suspected IBD were diagnosed by proximal and distal endoscopy, MRI, demographic, clinical, and histological and molecular characteristics. Symptomatic non-IBD patients served as controls. Results. Of 100 pediatric patients, 62 had IBD (39 Crohn's disease (CD), 19 ulcerative colitis (UC), 4 IBD unclassified (IBDU)) and 38 other diseases. Median age at diagnosis for IBD was 13.1 years (56.4% males), median symptom duration 6 months, and 69% L3 (Vienna classification). With 195,000 children aged <18 years in the catchment area, the incidence rate of IBD per 100,000/years inhabitants was 10.9 (6.8 for CD, 3.6 for UC, and 0.6 IBDU) and for those aged <16 years (178,500) the incidence rate was 10.6. The higher NOD2 allele frequency among children may partly contribute to the increase. Conclusions. The results indicate a marked rise in the incidence of CD in contrast to no increase in UC in South-Eastern Norway, compared with the figures from the last 15 years. Time from onset of symptoms to diagnosis still represents a challenge for early characterization in IBD.

An Update on the Epidemiology of Inflammatory Bowel Disease in Asia

A rising trend in the incidence and prevalence of inflammatory bowel disease (IBD) in Asia has been recognized for the past two decades. It has been postulated that this phenomenon may be related to the westernization of lifestyles, including changes in dietary habits and environmental changes such as improved sanitation and industrialization. Previously we reported that the incidence and prevalence rates of IBD in Asia were low compared with the West, but there was a notably rising secular trend. In this review, we summarize the recent epidemiological data in Asia, characterize the clinical features, risk factors and genetic susceptibility of Asian IBD patients, and compare these to those of Western IBD patients. In the past decade, the incidence and prevalence of IBD reported across Asia, particularly in East Asia, has continued to increase. Familial clustering is generally uncommon in East Asia but appears to be higher in West Asia. The genetic susceptibilities in Asian IBD patients differ from those of White patients, as NOD2/CARD15 mutations are much less common. The clinical phenotypes and complication rates of Asian IBD resemble the White population in general, but with some differences, including lower surgical rates, higher prevalence of males, and higher prevalence of ileocolonic involvement among East Asian Crohn's disease patients, and a low frequency of primary sclerosing cholangitis among IBD patients in East and Southeast Asia.

Geographic distribution and ecological studies of inflammatory bowel disease in southeastern Norway in 1990–1993

The purpose was to study the spatial distribution of cases of inflammatory bowel disease (IBD) and characterize municipalities with high incidences in a search for environmental risk factors. Spatial clustering of patients diagnosed with IBD during 1990-1993 were studied in 4 counties in southeastern Norway, and an ecological analysis was conducted to study the relationship between risk of IBD in the municipalities and their characteristics such as population, health care, urban/rural change, and socioeconomic change. One cluster consisting of 4 municipalities was identified for IBD in Østfold county (P = 0.011). The ecological analysis showed that the incidence rate of IBD was 33% (95% confidence interval [CI]: 2%-75%) higher in municipalities with the highest level of education compared to the lowest level of education and 35% (2%-78%) higher in urban than rural municipalities. The incidence rate was 11% (1%-20%) lower in municipalities with a high urban/rural change compared to municipalities with low urban/rural change. Individuals living in high-risk municipalities were 3 times (1.57-5.45) more likely to have a first-degree family member with IBD than individuals living in normal-risk municipalities. The geographic distribution of cases with IBD is not uniformly distributed and is related to urbanization, level of education, and moving pattern. Geographic distribution may be explained by either changes in environment-host relationships or neurobiological mechanisms due to stress and economic frustration. These factors and genetic predisposition might also explain increased familial clustering. Spatial clustering was significant neither for Crohn's disease CD nor ulcerative colitis (UC) but showed a stronger tendency within the CD group.

A Population-based Ecologic Study of Inflammatory Bowel Disease: Searching for Etiologic Clues

The authors' objective in this study was to determine geographic variations in the incidence of inflammatory bowel disease (IBD), specifically Crohn's disease and ulcerative colitis, in the Canadian province of Manitoba and its association with the sociodemographic, geographic, and disease-related characteristics of the study population. Using the University of Manitoba IBD Epidemiology Database, the authors applied spatial and ecologic techniques to visualize, explore, and model the incidence of Crohn's disease and ulcerative colitis for the period 1990-2001. The study demonstrated marked, statistically significant geographic variability in rates of both Crohn's disease and ulcerative colitis associated with the characteristics of the study population. Incidences of Crohn's disease and ulcerative colitis were observed to be highest among non-Aboriginal persons, persons of high socioeconomic status, persons with the lowest rates of enteric infection, and persons with the highest rates of multiple sclerosis. The observation of an inverse association between IBD incidence and rates of reportable enteric infection at the population level is consistent with the "hygiene hypothesis," which suggests that early exposure to enteric agents affords protection against eventual development of IBD. The positive association between IBD incidence rates and multiple sclerosis suggests that these two chronic, immunologically mediated diseases may have a common environmental etiology. This study underscores the importance of environment in IBD causation.

Increasing Incidences of Inflammatory Bowel Disease and Decreasing Surgery Rates in Copenhagen City and County, 2003–2005: A Population-Based Study from the Danish Crohn Colitis Database

A continuous increase in the incidence of inflammatory bowel disease (IBD), Crohn's disease (CD), ulcerative colitis (UC), and indeterminate colitis (IC) has been suggested. Since Denmark provides excellent conditions for epidemiological research, we aimed to describe contemporary IBD incidence rates and patient characteristics in Copenhagen County and City. All patients diagnosed with IBD during 2003-2005 were followed prospectively. Demographic and clinical characteristics, such as disease extent, extraintestinal manifestations, smoking habits, medical treatment, surgical interventions, cancer, and death, were registered. Five-hundred sixty-two patients were diagnosed with IBD, resulting in mean annual incidences of 8.6/10(5) for CD, 13.4/10(5) for UC, and 1.1/10(5) for IC. Time from onset to diagnosis was 8.3 months in CD and 4.5 months in UC patients. A family history of IBD, smoking, and extraintestinal manifestations was significantly more common in CD than in UC patients. Only 0.6% of UC patients had primary sclerosing cholangitis. In CD, old age at diagnosis was related to pure colonic disease, whereas children significantly more often had proximal and extensive involvement. Twelve percent of CD patients and 6% of UC patients underwent surgery during the year of diagnosis, significantly less than earlier reported. The incidence of IBD in Copenhagen increased noticeably during the last decades. Time from onset of symptoms until diagnosis decreased markedly, extent of CD was related to age at diagnosis, and the risk of surgery was low in UC.

Acute Gastroenteritis Is Followed by an Increased Risk of Inflammatory Bowel Disease

Bacterial intestinal infections have been implicated as a possible cause of exacerbation of inflammatory bowel disease (IBD). We explored the relationship between infectious gastroenteritis and the occurrence of IBD using data from the General Practice Research Database. A cohort of patients aged 20-74 years with an episode of acute infectious gastroenteritis (n = 43,013) was identified. From the same source population, an age-, sex-, and calendar time-matched control group free of gastroenteritis was sampled (n = 50,000). Both cohorts were followed up for a mean duration of 3.5 years. The estimated incidence rate of IBD was 68.4 per 100,000 person-years after an episode of gastroenteritis and 29.7 per 100,000 person-years in the control cohort. The hazard ratio of IBD was 2.4 (95% confidence interval [CI], 1.7-3.3) in the gastroenteritis cohort compared with the control cohort, and the excess risk was greater during the first year after the infective episode (hazard ratio, 4.1; 95% CI, 2.2-7.4). The relative risk of developing Crohn's disease in the gastroenteritis cohort was greater than that of ulcerative colitis, especially during the first year after the infective episode (hazard ratio, 6.6; 95% CI, 1.9-22.4). Our results are compatible with the hypothesis that infectious agents causing an episode of infectious gastroenteritis could play a role in the initiation and/or exacerbation of IBD.

Incidence and clinical presentation of IBD in children: Comparison between prospective and retrospective data in a selected Norwegian population

Objective. The results of recent research suggest that there is an increasing incidence of inflammatory bowel disease (IBD) among children. Newly diagnosed IBD was compared between two consecutive 6-year periods in the same catchment area of southeastern Norway. Material and methods. Children subjected to endoscopy from 1993 to 2004 were recorded retrospectively in the first 6-year period and prospectively for the subsequent period. The mean size of the child population under 16 years in the area was 70,500. The study reports on incidence numbers, age at diagnosis, disease distribution and clinical presentation at diagnosis. Results. There were 23 incident cases of IBD in the first period and 25 in the subsequent period. The rates of Crohn's disease (CD) for the two periods were, respectively, 1.95 and 3.64, and for ulcerative colitis (UC) 3.67 and 2.05/100,000 children/year. Total incidence rates of IBD for the two periods were 5.6 and 5.7, respectively, similar to the findings of the IBSEN study of 1990–94. The change in CD and UC rates from the first to the second period can be explained by better methods of diagnosis. Conclusions. The total incidence of IBD was not changed between time periods, whereas a trend towards an increase in CD and a reduction in UC was recorded. The incidence rates are in accordance with previously reported national and international data from the past decade. The extent of disease in CD and UC may indicate a serious prognosis of IBD among children.

Epidemiology of inflammatory bowel disease in adults who refer to gastroenterology care in Romania: a multicentre study.

The Romanian Society of Gastrointestinal Endoscopy developed a multicentre, prospective study to evaluate the frequency and epidemiological features of inflammatory bowel disease (IBD) in an adult population that refers to gastroenterology centres in Romania. Eighteen centres with adequate diagnostic and therapeutic facilities uniformly distributed across Romania reported through a proforma the new and old IBD cases between 1 June 2002 and 1 June 2003. The rates of incidence and prevalence of ulcerative colitis (UC) and Crohn's disease (CD) have been reported per 100 000 inhabitants. Epidemiological features and disease characteristics were analysed. During the study, 407 cases of UC (163 incident cases) and 254 cases of CD (85 incident cases) were identified. The incidence in the referral population was 0.97/100 000 and 0.50/100 000 for UC and CD, respectively, whereas the prevalences was 2.42/100 000 and 1.51/100 000 for UC and CD, respectively. A slight male predominance, wider age distribution and predominant urban residence were the main demographic features of incident cases; smoking and appendectomy/appendicitis were infrequent in UC, while a higher proportion of CD patients were smokers. Lower rates of severe, extensive or complicated IBD were noted as compared with the literature. Incidence and prevalence rates of IBD in Romania are low. Predominant male involvement and a wider distribution of incident cases were the main demographic features in our population. IBD in our patients had a more 'benign' course as compared with the literature, with lower rates of severe, extensive or complicated disease and a small proportion of patients who need surgery.

Epidemiology of chronic inflammatory bowel disease in the Northern area of Huelva

To know the different epidemiologic aspects of chronic inflammatory bowel disease (IBD) in the Northern area of the province of Huelva. we carried out a retrospective (1980-1996) and prospective (1996-2003) study of all patients diagnosed with IBD in the Northern area of Huelva, with 77,856 inhabitants. The distribution of Crohn s disease (CD) and ulcerative colitis (UC) was analyzed, as well as sex, age and smoking habit at the time of diagnosis, familial aggregation, appendicectomy rate, phenotype (anatomical site and clinical types), extraintestinal manifestations, and immunosuppressive therapy or surgical requirements. 70 patients with IBD were studied, 40 with UC and 30 with CD. Sex distribution was 39 (55.7%) males (55% with CD vs 56.6% with UC; NS) and 31 (44.3%) females (45% with CD vs 43.3% with UC; NS). Mean age at presentation was 44.7 +/- 19.32 years in UC vs 32.3 +/- 16.43 in CD; p < 0.001. Familial association was 7.1%. Previous appendicectomy was referred in 2.5% of patients with UC vs 36.7% of those with CD (p < 0.001), and the percentage of smokers was also higher in CD 66.7% vs CU 12.5% (p < 0.001). Anatomical site in UC was: proctitis, 20%; proctosigmoiditis/left colon, 42.5%; extensive colitis, 25%; and pancolitis, 12.5%; in CD was: terminal ileum, 43.3%; colon, 20%; and ileo-colon, 36.7%. The disease patterns were: inflammatory 56.7%, obstruction 26.7%, and fistulization 16.7%. Extraintestinal manifestations were diagnosed in 7.5% of patients with UC vs 16.6% patients with CD; surgery was performed in one patient with UC vs 10 with CD, and one patient with UC required immunosuppressive treatment vs 12 with CD. A multivariant analysis showed that younger age and smoking habit were risk factors for CD vs advanced age in UC, in which case, the smoking habit was a protective factor. The mean incidence rate of IBD starting from 1996 and expressed in cases/100,000 inhabitants/year was 5.2 for UC and 6.6 for CD. The mean incidence of UC in our area was 5.2 cases/100,000/inhabitants/year, and 6.6 for CD. Patients presenting with CD are diagnosed at a significantly younger age that those with UC; the smoking habit is a risk factor for CD while it protects from UC. The characteristics of IBD in our geographical area do not differ substantially from those in other regions of Spain.

Incidencia y prevalencia en enfermedad inflamatoria intestinal crónica: Estudio asturiano en cinco áreas (EIICEA). España

To know and to compare Inflammatory Bowel Disease (IBD) Incidence and Prevalence rates in in five areas of Asturias (Spain). We conducted a prospective epidemiologic study of IBD in the Province of Liege (1 million inhabitants). We conducted a descriptive, populational, collaborative epidemiologic study, retrospective between 1954 and 1993 and prospective between 1994 and 1997. All patients diagnosed according to a standard protocol for case ascertainment and definition of IBD, aged 14 years or more are included, in five areas of Asturias (Spain) (461,965 inhabitants). For the period 1954 to 1997, 1018 IBD have been diagnosed [565 ulcerative colitis (UC) (55.5%), 415 Crohn's disease (CD) (40.8%) and 38 undefined IBD (IC) (3.7%)]; [482 women (47.2%), 536 males (52.8%)]. In the 4 year-prospective period, 306 cases were collected: 176 UC (57.51%), 110 CD (35.94) and 20 IC (6.53%); UC/CD: 1.6. Without appreciable and significant differences between Frequency of illness groups and sexes. IBD incidence rate (per 100,000 per year) (1954-97) is 5.12 (95% CI = 3.05-7.18) (UC: 2.84; CD: 2.08; IC: 0.19; UC/CD 1.36). In the 4 years- prospective study, IBD incidence rate is 16.55 (95% CI = 12.84-20.25), (UC: 9.52; CD: 5.95; IC: 1.08; UC/CD: 1.6). IBD prevalence rate in 1997 is 205.21 (95% CI = 182.14-227.29), (UC: 109.96; CD: 87.45; IC: 7.79). Comparisons have settled down among the studied areas, without finding differences statistically significant. Inflammatory Bowel Disease incidence and prevalence rates of in our region are homogeneous between the cities investigated and superior than those historically reported in Spanish studies. These results were similar to those observed in European studies.

Inflammatory bowel disease in children and adolescents: Working Group Report of the First World Congress of Pediatric Gastroenterology, Hepatology, and Nutrition.

Inflammatory bowel disease in children and adolescents: Working Group Report of the First World Congress of Pediatric Gastroenterology, Hepatology, and Nutrition.

Polymorphisms in Tumour Necrosis Factor and Adhesion Molecule Genes in Patients with Inflammatory Bowel Disease: Associations with HLA-DR and -DQ Alleles and Subclinical Markers

Background: When investigating susceptibility to inflammatory bowel disease (IBD), a multifactorial disorder with a genetic predisposition, polymorphisms of molecules with immunoregulatory function are of potential interest. This is the first time that the polymorphisms of HLA-DR and -DQ, tumour necrosis factor (TNF), E-selectin (CD62E), L-selectin (CD62L), and intercellular adhesion molecule 1 (ICAM-1, CD54) were determined in Estonians, a population with a low IBD incidence rate, and their occurrence investigated in subgroups of a total of 53 IBD patients. Methods: The reverse hybridization principle and sequence specific primers were used for HLA genotyping. To analyse the TNF and adhesion molecule polymorphisms, the polymerase chain reaction with subsequent restriction fragment length polymorphism or single-strand conformation polymorphism method was used. Results: In the subgroup of antineutrophil cytoplasmic antibody (ANCA)-positive ulcerative colitis (UC) patients we found a higher frequency of the TNF2 (20.8% versus 0.0% in ANCA-negative UC patients, P = 0.051) and HLA-DRB1*15 allele (35.4% versus 15.7% in controls; P = 0.004). Of ANCA-positive UC patients 87.5% were carriers of one of these alleles (22.2% among ANCA-negative UC patients (P < 0.001, Pc = 0.039) and 51.4% among controls (P = 0.002). Specific typing of HLA-DRB1*15 alleles showed that the HLA-DRB1*1501 allele was responsible for the HLA-DRB1*15 association with ANCA-positive UC. Associations of ICAM-1, E-selectin, or L-selectin polymorphisms with IBD were not found. Conclusions: TNF2 and HLA-DRB1*15 alleles were associated with ANCA-positive UC in the investigated population. ANCA might be a useful marker, at least in some ethnic groups, for dividing IBD patients into genetically more homogeneous subgroups.

INCIDENCE OF PEDIATRIC INFLAMMATORY BOWEL DISEASE AND ASSOCIATED LIVER DISEASE IN SOUTHWESTERN SWEDEN 1983-96.

69 Aims: In a welldefined population of children (300 000 children<16 years) in south western Sweden the incidence of inflammatory bowel disease (IBD) was prospectively monitored during 14 years (1983-96). During the second seven year period associated liver disease was also studied. Methods: IBD was defined by clinical, histological, endoscopical or radiological evidence of IBD. The diagnoses of ulcerative colitis (UC) and Crohn's disease (CD) were accepted only if histopathological findings typical of UC or CD were found in combination with mucosal changes at endoscopy or radiology. Otherwise the diagnosis of indeterminate colitis (IC) was used. All new cases of IBD were included in the study. Aminotransferases and gammaglutamyltranspeptidase were tested in the majority of new cases from 1990 and later and in selected cases with biochemical abnormalities a liver biopsy and /or endoscopical retrograde cholangiography (ERC) were performed. Liver disease was defined by biochemical, histological or radiological changes. Results: 279 patients with IBD, 158 boys and 121 girls, were diagnosed, giving an incidence rate of 6.6 per 100 000 children per year, with an increasing incidence rate over the study period. UC was found in 133 patients, CD in 98 and IC in 48 patients. The incidence rate of CD remained stable but there was an increase for both UC and IC. There was a male predominance with 1.3:1 over the whole study period, but this was less prominent during the second half of the study period. Fourteen patients (8.3%) had histological evidence of liver disease and another nine (5.4%) had elevated aminotransferases at repeated occasions. In UC, 22.1% of the patients, showed evidence of liver abnormalities. Conclusions: The incidence rate of IBD remained stable until 1990 but after that a significant increase was found. This was caused by an increase of UC and IC, while CD decreased. Liver abnormalities were found in a significant proportion and liver involvement in pediatric IBD, especially in UC, might be underestimated.

Measles Vaccination and Inflammatory Bowel Disease in Japanese Children

To the Editor: The report of Thompson et al.(1) suggests an association between measles vaccination and inflammatory bowel disease (IBD), particularly Crohn's disease (CD). Japan is a country in which the prevalence of IBD is far lower than in European countries and in the United States, although a rise has become apparent in adults in recent years (2). It is therefore important to report the incidence rates of IBD in Japanese children and performance rates of measles vaccination in Japan. Mass vaccination against measles was introduced in 1978 in Japan, and the nationwide performance rate has been between 70% and 90% (3). The efficacy rate of the vaccination was 96.2% to 97.8% (3), and the vaccination program has been thought to be successful. Measles, mumps, and rubella vaccine was introduced in April 1989, but it had to be suspended because of a high complication rate of meningitis in April 1993, and it has not been reinstituted. A nationwide epidemiologic survey of ulcerative colitis (UC) and CD in children less than 16 years old was carried out from 1979 to 1993(4). The total number of the patients collected was 578 with UC and 260 with CD by 1993, whereas the total population less than 16 years old was 22,400,000 to 29,000,000 in each year of this period. The number of new UC and CD patients occurring in each year was almost the same after 1979; however, new UC patients per 100,000 increased in 1993 and new CD patients per 100,000 in 1992 and 1993, after having remained at a plateau for a decade after the time of introduction of measles vaccination. Incidence rates of UC per 100,000 were 0.08 in 1979 (population less than 16 years old: 29,081,000), 0.085 in 1980 (28,968,316), 0.12 in 1985 (27,647,604), 0.11 in 1990 (24,395,897), 0.1 in 1992 (23,137,200), and 0.18 in 1993 (22,407,000). Rates of CD were 0.04 in 1979, 0.05 in 1980, 0.06 in 1985, 0.03 in 1990, 0.05 in 1991, 0.10 in 1992 and 0.12 in 1993. Magnitudes of increased incidence rates from 1979 to 1993 are double in UC and triple in CD. The age at onset was distributed throughout all ages from 0 to 15 years in both disorders, but more patients 8 years old and older were seen with UC and more 10 years old and older with CD. From results of this survey, it could be proposed that Japanese do not have a genetic predisposition to IBD; nonetheless, a causal role for various environmental factors should be taken into consideration in describing the etiology of this disorder in Japanese people. If measles vaccine increases the risk of developing CD but not UC, the increases of CD and UC in Japan a decade after introduction of the vaccination can not be explained solely by this factor. Another explanation for this increase may be changes in life style, including the change in diet from traditional Japanese foods to European or North American foods; delayed exposure to enteric infections(5); and low infant mortality(6). We thank Dr. H. Urashima for kind permission to use his data describing IBD in Japanese children. Y. Yamashiro *J. A. Walker-Smith T. Shimizu S. Oguchi Y. Ohtsuka Department of Paediatrics; Juntendo University School of Medicine; Tokyo, Japan;*University Department of Paediatric Gastroenterology; Royal Free Hospital; London, United Kingdom

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

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. 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. 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. 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.

Incidence of inflammatory bowel disease in Italy: a nationwide population-based study. Gruppo Italiano per lo Studio del Colon e del Retto (GISC)

The epidemiology of inflammatory bowel disease (IBD) in Southern Europe is still unclear. Sporadic reports suggest a lower incidence of IBD in Italy than in other Western Countries and the USA. A nationwide population-based study was carried out to estimate IBD incidence rates in eight Italian cities. All new cases of IBD diagnosed over 4 years in the target populations were collected from multiple information sources. From 1989 to 1992, 509 ulcerative colitis (UC), 222 Crohn's disease (CD) and 10 undefined IBD cases were collected, giving age-adjusted incidence rates (per 100,000 per year) of 5.2 for UC and 2.3 for CD. Using the capture-recapture method, an estimated completeness of 0.81 was obtained for case archives, without appreciable and significant differences between areas. The rates computed after correcting underestimation were 6.8 for UC and 2.8 for CD. The sex ratio M/F was 1.7 for UC and 1.0 for CD. The highest age-specific incidence rates were between 30 and 39 years for UC and between 20 and 29 years for CD. The incidence rate of CD in italy is homogeneous between the cities investigated and lower than those reported for other Mediterranean countries. In contrast, the UC incidence rate is within the range of those reported in European studies. A wide variability in the UC rates between the cities was also observed. These results could be related to different environmental factors or the genetic background of the populations, or both.