Crohn's disease in Blackpool--incidence and prevalence 1968-80

Management of the elderly patients with inflammatory bowel disease: practical considerations

The aging U.S. population will approach 20% of the total population by 2030. The number of older patients with inflammatory bowel disease is anticipated to increase accordingly bringing the burden of multiple comorbidities, polypharmacy with drug interactions, the aging immune system, and extended social and financial issues to overall management of an already challenging management of these patients. Each of these concerns is measured by the metric of distinguishing the "fit versus frail" elderly and will be discussed in this review with an emphasis on a practical guide to therapy.

Incidence of inflammatory bowel disease in the province of Styria, Austria, from 1997 to 2007: a population-based study

BACKGROUND

The incidence of inflammatory bowel disease (IBD) varies widely between different countries. This large variation is also observed for the incidence of its main two forms, ulcerative colitis (UC) and Crohn's disease (CD). Controversy exists whether IBD incidence is increasing, especially in western countries. Currently no data are available for Austria. This study therefore aimed to evaluate for the first time the incidence of IBD over an eleven-year period in Styria, a province of Austria with a population of 1.2 million.

METHODS

All patients with an initial diagnosis of IBD between 1997 and 2007, who were Styrian residents, were eligible for this retrospective study. Data were acquired from electronically stored hospital discharge reports and individual reports by patients and physicians. According to population density Styria was divided into two rural and one urban area.

RESULTS

Throughout the study period 1527 patients with an initial diagnosis of IBD were identified. The average annual incidence was 6.7 (95% CI 6.2-7.1) per 100,000 persons per year for CD and 4.8 (95% CI 4.5-5.2) for UC. The average annual incidence increased significantly (p<0.01) for both diseases during the 11 year study period. Median age at initial diagnosis was 29 years (range 3-87) for CD and 39 years (range 3-94) for UC. At diagnosis, 8.5% of all IBD patients were <18 years of age. The incidence of both CD and UC was significantly higher in the urban area than in rural areas (CD: 8.8, 95% CI 7.8-9.8 versus 5.5, 95% CI 4.7-6.4 and 5.9, 95% CI 5.3-6.7; [p<0.001]; UC: 5.8, 95% CI 5.1-6.6 versus 4.0, 95% CI 3.4-4.7 and 4.7, 95% CI 4.1-5.4; [p=0.04]).

CONCLUSION

We observed an overall increase in the incidence of ulcerative colitis and Crohn's disease in a part of Austria during an eleven year period. IBD was more predominant in the largest urban area than in rural areas.

Increasing incidence and prevalence of the inflammatory bowel diseases with time, based on systematic review

BACKGROUND & AIMS

We conducted a systematic review to determine changes in the worldwide incidence and prevalence of ulcerative colitis (UC) and Crohn's disease (CD) in different regions and with time.

METHODS

We performed a systematic literature search of MEDLINE (1950-2010; 8103 citations) and EMBASE (1980-2010; 4975 citations) to identify studies that were population based, included data that could be used to calculate incidence and prevalence, and reported separate data on UC and/or CD in full manuscripts (n = 260). We evaluated data from 167 studies from Europe (1930-2008), 52 studies from Asia and the Middle East (1950-2008), and 27 studies from North America (1920-2004). Maps were used to present worldwide differences in the incidence and prevalence of inflammatory bowel diseases (IBDs); time trends were determined using joinpoint regression.

RESULTS

The highest annual incidence of UC was 24.3 per 100,000 person-years in Europe, 6.3 per 100,000 person-years in Asia and the Middle East, and 19.2 per 100,000 person-years in North America. The highest annual incidence of CD was 12.7 per 100,000 person-years in Europe, 5.0 person-years in Asia and the Middle East, and 20.2 per 100,000 person-years in North America. The highest reported prevalence values for IBD were in Europe (UC, 505 per 100,000 persons; CD, 322 per 100,000 persons) and North America (UC, 249 per 100,000 persons; CD, 319 per 100,000 persons). In time-trend analyses, 75% of CD studies and 60% of UC studies had an increasing incidence of statistical significance (P < .05).

CONCLUSIONS

Although there are few epidemiologic data from developing countries, the incidence and prevalence of IBD are increasing with time and in different regions around the world, indicating its emergence as a global disease.

Perinatal and early life risk factors for inflammatory bowel disease

AIM: To investigate associations between perinatal risk factors and subsequent inflammatory bowel disease (IBD) in children and young adults.

METHODS: Record linked abstracts of birth registrations, maternity, day case and inpatient admissions in a defined population of southern England. Investigation of 20 perinatal factors relating to the maternity or the birth: maternal age, Crohn’s disease (CD) or ulcerative colitis (UC) in the mother, maternal social class, marital status, smoking in pregnancy, ABO blood group and rhesus status, pre-eclampsia, parity, the infant’s presentation at birth, caesarean delivery, forceps delivery, sex, number of babies delivered, gestational age, birthweight, head circumference, breastfeeding and Apgar scores at one and five minutes.

RESULTS: Maternity records were present for 180 children who subsequently developed IBD. Univariate analysis showed increased risks of CD among children of mothers with CD (P = 0.011, based on two cases of CD in both mother and child) and children of mothers who smoked during pregnancy. Multivariate analysis confirmed increased risks of CD among children of mothers who smoked (odds ratio = 2.04, 95% CI = 1.06-3.92) and for older mothers aged 35+ years (4.81, 2.32-9.98). Multivariate analysis showed that there were no significant associations between CD and 17 other perinatal risk factors investigated. It also showed that, for UC, there were no significant associations with the perinatal factors studied.

CONCLUSION: This study shows an association between CD in mother and child; and elevated risks of CD in children of older mothers and of mothers who smoked.

Epidemiology of pediatric inflammatory bowel disease: a systematic review of international trends

BACKGROUND

Temporal trends in the incidence of pediatric-onset inflammatory bowel disease (IBD) are controversial and a wide range of estimates have been reported worldwide. We conducted a systematic review of research describing the epidemiology of childhood-onset IBD to assess changes in incidence rates over time and to evaluate international differences.

METHODS

The following electronic databases were searched for articles published 1950-2009: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane IBD/Functional Bowel Disorders Group Specialised Trial Register. All included studies reported incidence or prevalence of IBD, Crohn's disease (CD) or ulcerative colitis (UC). Two authors independently completed the data extraction form for each eligible study. Choropleth maps demonstrated the international incidence of IBD, CD, and UC. Incidence of CD and UC was graphed using data from studies reporting rates in multiple time periods.

RESULTS

The search yielded 2209 references and review resulted in 139 included studies from 32 countries. A wide range of incidence was reported internationally; however, rates of IBD were not described in most countries. Twenty-eight studies (20.1%) used statistical analysis to assess trends over time, and 77.8% reported statistically significantly increased incidence of pediatric IBD. Of studies calculating statistical trends in CD incidence, 60% reported significantly increased incidence. Of similar UC studies, 20% reported significantly increased incidence.

CONCLUSIONS

Globally rising rates of pediatric IBD (due primarily to the rising incidence of CD) was demonstrated in both developed and developing nations; however, most countries lack accurate estimates. Analyzing incidence trends may help identify specific environmental and genetic risk factors for pediatric IBD.

Hospitalized prevalence and 5-year mortality for IBD: record linkage study

AIM

To establish the hospitalized prevalence of severe Crohn's disease (CD) and ulcerative colitis (UC) in Wales from 1999 to 2007; and to investigate long-term mortality after hospitalization and associations with social deprivation and other socio-demographic factors.

METHODS

Record linkage of administrative inpatient and mortality data for 1467 and 1482 people hospitalised as emergencies for > or = 3 d for CD and UC, respectively. The main outcome measures were hospitalized prevalence, mortality rates and standardized mortality ratios for up to 5 years follow-up after hospitalization.

RESULTS

Hospitalized prevalence was 50.1 per 100 000 population for CD and 50.6 for UC. The hospitalized prevalence of CD was significantly higher (P < 0.05) in females (57.4) than in males (42.2), and was highest in people aged 16-29 years, but the prevalence of UC was similar in males (51.0) and females (50.1), and increased continuously with age. The hospitalized prevalence of CD was slightly higher in the most deprived areas, but there was no association between social deprivation and hospitalized prevalence of UC. Mortality was 6.8% and 14.6% after 1 and 5 years follow-up for CD, and 9.2% and 20.8% after 1 and 5 years for UC. For both CD and UC, there was little discernible association between mortality and social deprivation, distance from hospital, urban/rural residence and geography.

CONCLUSION

CD and UC have distinct demographic profiles. The higher prevalence of hospitalized CD in more deprived areas may reflect higher prevalence and higher hospital dependency.

Hospitalized prevalence and 5-year mortality for IBD: Record linkage study

AIM: To establish the hospitalized prevalence of severe Crohn’s disease (CD) and ulcerative colitis (UC) in Wales from 1999 to 2007; and to investigate long-term mortality after hospitalization and associations with social deprivation and other socio-demographic factors.

METHODS: Record linkage of administrative inpatient and mortality data for 1467 and 1482 people hospitalised as emergencies for ≥ 3 d for CD and UC, respectively. The main outcome measures were hospitalized prevalence, mortality rates and standardized mortality ratios for up to 5 years follow-up after hospitalization.

RESULTS: Hospitalized prevalence was 50.1 per 100 000 population for CD and 50.6 for UC. The hospitalized prevalence of CD was significantly higher (P < 0.05) in females (57.4) than in males (42.2), and was highest in people aged 16-29 years, but the prevalence of UC was similar in males (51.0) and females (50.1), and increased continuously with age. The hospitalized prevalence of CD was slightly higher in the most deprived areas, but there was no association between social deprivation and hospitalized prevalence of UC. Mortality was 6.8% and 14.6% after 1 and 5 years follow-up for CD, and 9.2% and 20.8% after 1 and 5 years for UC. For both CD and UC, there was little discernible association between mortality and social deprivation, distance from hospital, urban/rural residence and geography.

CONCLUSION: CD and UC have distinct demographic profiles. The higher prevalence of hospitalized CD in more deprived areas may reflect higher prevalence and higher hospital dependency.

Inflammatory bowel disease in the elderly

This article reviews the epidemiology, clinical manifestations, diagnosis, prognosis, and treatment of inflammatory bowel disease (IBD), which will grow in prevalence as the population ages. Prognosis of late-onset ulcerative colitis (UC) is generally similar to that of early-onset UC, whereas in Crohn disease it is probably better because of a tendency for colonic involvement. Disease complications are related more to the duration of the inflammatory bowel disease than the subject's current age. The diagnosis in elderly patients can be challenging due to the large number of conditions that mimic IBD on radiologic, endoscopic, and histologic testing. Distinguishing these conditions from IBD will significantly alter prognosis and treatment. Complications related to IBD and its treatment are common and must be recognized early to limit their impact in a vulnerable elderly population.

Prevalence of Inflammatory Bowel Disease in the Canton of Vaud (Switzerland): A population-based cohort study

BACKGROUND AND AIMS

Because of the changing epidemiology of Inflammatory Bowel Diseases (IBD), we set out to characterize the population-based prevalence of Crohn's Disease (CD) and Ulcerative Colitis (UC) in a defined population of Switzerland.

METHODS

Adult IBD patients were identified by a cross-matched review of histological, hospital and gastroenterologist files throughout a geographical defined population (Canton of Vaud). Demographic factors statistically significantly associated with prevalence were evaluated using a stepwise Poisson regression analysis. Results were compared to IBD prevalence rates in other population-based studies and time trends were performed, based on a systematic literature review.

RESULTS

Age and sex-adjusted prevalence rates were 205.7 IBD (100.7 CD and 105.0 UC) cases per 10(5) inhabitants. Among 1016 IBD patients (519 CD and 497 UC), females outnumbered males in CD (p<0.001), but males were more represented in elderly UC patients (p=0.008). Thus, being a male was statistically associated with UC (Relative Risk (RR) 1.25; p=0.013), whereas being a female was associated with CD (RR 1.27; p=0.007). Living in an urban zone was associated with both CD and UC (RR 1.49; p<0.001, 1.63; p<0.001, respectively). From 1960 to 2005, increases in UC and CD prevalences of 2.4% (95%CI, 2.1%-2.8%; p<0.001) and 3.6% (95%CI, 3.1%-4.1%; p<0.001) per annum were found in industrialised countries.

CONCLUSIONS

Extrapolating our data to all of Switzerland yields an estimate of 12,000 IBD cases for the country, or 1 in 500 inhabitants. Our study gives support to an increase in IBD prevalence in Europe.

The role of smoking in Crohn's disease as defined by clinical variables

The development of Crohn's disease (CD) is related to an interaction of genetic and environmental factors, with tobacco smoking being one of the most commonly studied environmental factors. In 1998, the Vienna classification was created to define CD by using three accepted clinical variables: age at diagnosis, disease behavior, and disease location. In this qualitative systematic review, articles examining the relationship between smoking and CD, using variables outlined in the Vienna classification, were identified utilizing multiple health databases. Current smoking was found to be associated with late-onset CD (> or =40 years old) and current smokers were more likely to progress to stricturing or penetrating type CD than were nonsmoking patients. Conflicting evidence exists regarding the relationship between smoking with respect to CD disease location. The Vienna classification is an important tool in permitting comparisons and predicting clinical course among CD cases, especially when smoking status is taken into account.

The epidemiology of inflammatory bowel disease in Canada: a population-based study

BACKGROUND

Previously, we have demonstrated a high incidence and prevalence of Crohn's disease (CD) and ulcerative colitis (UC) in the Canadian province of Manitoba. However, the epidemiology of inflammatory bowel disease (IBD) in other regions of Canada has not been defined. The aim of this study was to estimate the incidence and prevalence of CD and UC in diverse regions of Canada and the overall burden of IBD in Canada.

METHODS

We applied a common case identification algorithm, previously validated in Manitoba to the provincial health databases in British Columbia (BC), Alberta (AB), Saskatchewan (SK), Manitoba (MB), and Nova Scotia (NS) to determine the age-adjusted incidence rates per 100,000 person-years for 1998-2000 and prevalence per 100,000 for mid 2000 and to estimate the IBD burden in Canada. Poisson regression was used to assess differences in incidence rates and prevalence by gender, age, and province.

RESULTS

The incidence rate for CD ranged from 8.8 (BC) to 20.2 (NS), and for UC ranged from 9.9 (BC) to 19.5 (NS). The prevalence of CD was approximately 15- to 20-fold higher than the incidence rate, ranging from 161 (BC) to 319 (NS). This was similar for the prevalence of UC, which ranged from 162 (BC) to 249 (MB). Adjusting for age and province, the female:male ratio for incidence ratio was 1.31 (p < 0.0001) for CD and 1.02 (n.s.) for UC and was mostly stable across the five provinces.

CONCLUSIONS

Approximately 0.5% of the Canadian population has IBD. Canada has the highest incidence and prevalence of CD yet reported.

Crohn's disease in people exposed to clinical cases of bovine paratuberculosis

Mycobacterium avium subspecies paratuberculosis (Map), the cause of ruminant paratuberculosis, has been proposed as the causative agent of Crohn's disease. The objective of this study was to determine whether exposure to clinical cases of bovine paratuberculosis was a risk factor for Crohn's disease. A questionnaire was sent to dairy farmers living on premises where the occurrence or absence of clinical cases of bovine paratuberculosis had previously been determined. The prevalence of Crohn's disease was found to be similar to that reported in other studies in the United Kingdom and showed no association with bovine paratuberculosis. There was, however, a univariate association with geographical region. Ulcerative colitis showed univariate associations with age, frequency of contact with cattle and with smoking. The results do not support the hypothesis that Map plays a causative role in the aetiology of Crohn's disease.

The epidemiology and phenotype of Crohn's disease in the Chinese population

BACKGROUND

Inflammatory bowel disease is uncommon in Southeast Asia but is increasing in incidence. The epidemiology and phenotype of Crohn disease (CD) in the Chinese population is not well-known. The purpose of this study was to determine the incidence, temporal trend, clinical features, risk factors, extraintestinal manifestations, and the treatment of CD in the Chinese population of Hong Kong.

METHODS

We performed a single-center study of consecutive definite CD cases based on internationally accepted criteria, with strict exclusion of infective enterocolitis.

RESULTS

Eighty Chinese CD patients were recruited, characterized by male gender predominance (male:female ratio 2.5:1), no association with ever smoking (OR 1.02, 95% CI: 0.54-1.92), absence of familial clustering (0%), high proportion of upper gastrointestinal tract disease proximal to the terminal ileum (19%), and a low proportion of isolated terminal ileal disease (4%). The mean age at diagnosis was 33 years. Forty-five percent of patients had penetrating disease, 18% stricturing disease, and 37% had nonstricturing, nonpenetrating disease. Twenty-five percent of patients had at least 1 extraintestinal manifestation, and there was a high rate of ankylosing spondylitis (9%). The incidence of CD was 1.0 per 100,000 and has increased by 3 fold during the past decade. The age-adjusted incidence was 3.0 per 100,000 (95% CI: 2.3-3.7 per 100,000).

CONCLUSIONS

The incidence of CD in the Chinese is increasing. There are some notable epidemiological and phenotypic differences between Chinese CD with Caucasian CD including the lack of familial clustering, male predominance, and higher proportion of upper GIT involvement and lower frequency of isolated terminal ileal disease.

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.

Increasing incidence of Crohn's disease in Victorian children

BACKGROUND

The incidence of Crohn's disease has been increasing in Western communities, but there are no published studies which have examined this change in children in Australia. The centralization of pediatric gastroenterology services in Victoria provides an opportunity to examine these changes within one state.

METHODS

We undertook a retrospective study over a 31-year period of all children aged 16 years or less initially diagnosed with Crohn's disease at either the Royal Children's Hospital, or Monash Medical Center, Melbourne, Victoria.

RESULTS

We identified 351 patients who met the diagnostic criteria between 1971 and 2001. The incidence of Crohn's disease in children aged 16 years or less rose from 0.128 to 2.0 per 100,000 per year over the three decades (r = 0.964, P < 0.01). There was a disproportionate over-representation of children from an urban background (incidence rate ratio 1.66, 95% CI 1.28-2.16). Children currently being diagnosed had on average a lower erythrocyte sedimentation rate (ESR) and higher albumin than in previous decades. The use of flexible endoscopy has increased markedly (1970s: 60%; 1990s: 96%, P < 0.05) and the proportion of children recognized at diagnosis with upper gastrointestinal and colonic involvement has increased significantly.

CONCLUSION

There has been a significant increase in the incidence of Crohn's disease in Victorian children. The pattern of disease has also changed with colonic disease now more frequent, and inflammatory indices less abnormal. The increased use of endoscopy has established the frequent involvement of the upper gastrointestinal tract.

Epidemiology of inflammatory bowel disease--methodological considerations

The causes and mechanisms of action of inflammatory bowel disease have, so far, eluded discovery. Epidemiological studies have shown that ulcerative colitis tends to level off, whereas Crohn's disease tends to increase. Some of these changes may be due to diagnostic practices and increasing awareness of the disease and Crohn's colitis. The disease varies according to geographical location and a distribution along a north-south axis has been suggested. The differences may be due to study design, or may reflect differences in lifestyle, diet or be due to genetic predisposition triggered by environmental factors. Epidemiological studies designed to investigate such interactions may provide clues to its aetiology. Inflammatory bowel disease could, therefore, serve as a model for the importance of epidemiology when to test or reject the hypothesis of aetiology.

Validity and completeness of the General Practice Research Database for studies of inflammatory bowel disease

PURPOSE

The objective of this study was to evaluate the validity and completeness of the General Practice Research Database (GPRD) as a tool for research into inflammatory bowel disease epidemiology.

METHODS

Patients diagnosed with inflammatory bowel disease were identified from GPRD. Mailed surveys were sent to the general practitioner caring for a stratified random sample of 170 of these patients and collected information on the diagnosis of inflammatory bowel disease and the most recent surgery and hospitalization.

RESULTS

Usable surveys were returned for 157 patients (92%). The inflammatory bowel disease diagnosis was highly probable or probable in 144 (92%, 95% CI 86 to 96%). Among the 53 patients with a potentially incident inflammatory bowel disease diagnosis, 33 (62%) had the first recorded diagnosis in GPRD within 30 days of the date reported in the survey (median difference -8 days; interquartile range 0 to -81 days). Of 12 surgeries and 25 hospitalizations reported in the survey, 11 (92%) and 19 (76%) were identified in GPRD, respectively.

CONCLUSIONS

The diagnosis of inflammatory bowel disease in GPRD appears reliable for most patients. Important medical events such as hospitalizations and surgery are recorded at a high rate, although algorithms to identify these events are complex.

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.

Inflammatory bowel disease in the elderly

Approximately 15% of all patients with IBD first develop symptoms after age 65. As the number of elderly in the population continues to grow, clinicians should expect to see a greater number of elderly IBD patients. In general, the presenting features of IBD are similar to those encountered in younger patients, but the broad differential diagnosis of colitis in the elderly can make definitive diagnosis more challenging. Although most therapies for IBD have not been studied specifically in the elderly, as a general rule, medical and surgical treatment options are the same regardless of age. Osteoporosis, a condition generally associated with aging, should be managed aggressively in patients with IBD because many older persons already have a substantial baseline risk for accelerated bone loss.

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.

Abdominal surgery in the older Crohn's population

BACKGROUND

The surgical literature perceives that the elderly cohort of Crohn's patients may have increased risk with surgery.

METHODS

A retrospective review and prospective database analysis of all patients with histologically proven Crohn' s disease who had a laparotomy at a single Sydney teaching hospital were performed. The last laparotomy of each patient was included in the analysis for morbidity and mortality to assess whether an older cohort was at an increased risk.

RESULTS

A total of 156 patients had 298 laparotomies for histopathologically proven Crohn's disease. The frequency distribution of age at last laparotomy was bimodal, and the statistically determined cut-off age between younger and older cohorts was 55 years. Thirty-three patients were older than 55 years. There was no difference in duration of symptoms before first diagnosis (older, 17 months vs younger, 25 months), previous number of Crohn's operations (42.4 vs 39.8%), or duration of known Crohn's disease. Isolated large bowel disease was more common in the elderly cohort (42.4 vs 18.7%, chi2 = 8.09, P < 0.01). Small bowel and ileocaecal resections were more common in the younger cohort (72.4 vs 51.6%, chi2 = 5.19, P < 0.025). There was one death in each cohort (overall mortality 1.3%) and anastomotic leak rates (defined as the number of leaks per number of patients with anastomoses), were 4.3% (older) vs 5.3% (younger) despite frank sepsis present in 21.2% of all subjects at the time of surgery. The older group had more cardiac (18.2 vs 0.8%, P < 0.001) and respiratory complications (18.2 vs 2.4%; P = 0.0003) and a longer mean but not median postoperative hospital admission.

CONCLUSIONS

In conclusion, clinical features and presentation are similar in the older and younger Crohn's patients having a laparotomy. However, in the older patient there is a greater likelihood of large bowel disease, ileocaecal resection is done less commonly, there is a higher risk of minor cardiopulmonary postoperative complications, but with similar mortality and anastomotic leak rates to the younger patient.

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.

Incidence of Crohn's disease in four counties in southeastern Norway, 1990-93. A prospective population-based study. The Inflammatory Bowel South-Eastern Norway (IBSEN) Study Group of Gastroenterologists

BACKGROUND

Standardized criteria for Crohn's disease (CD) have only recently been developed, and prospective community-based incidence studies have been performed only during the past 3 decades. Geographic variations in incidence may therefore be due to differences in study design.

METHODS

From 1 January 1990 to 31 December 1993 all new cases of CD in four counties in southeastern Norway were prospectively registered.

RESULTS

A total of 225 new cases yielded an annual incidence of 5.8/10(5), with the highest incidence in mixed rural-urban areas. A peak of 11.2/10(5) in the annual incidence was found for the age group 15 to 24 years, with no significant differences in the overall annual incidence by gender. An average duration of 6 months of disease before diagnosis was unchanged during the 4 years. About half of the patients had isolated colonic disease, and one-quarter had isolated small-bowel disease.

CONCLUSIONS

This study confirms the high incidence figures for Scandinavia, with a particularly high incidence in mixed rural-urban areas. Ileocolonoscopy improves the accuracy of the diagnosis and of the determination of disease extent, which may have therapeutic implications for the treatment and follow-up of patients.

Inherited disorders of coagulation appear to protect against inflammatory bowel disease

BACKGROUND/AIMS

Crohn's disease and ulcerative colitis seem to be rarely associated with inherited diseases of coagulation. Histological and hematologic studies suggest that thrombotic mesenteric microvascular occlusion is involved in the pathogenesis of inflammatory bowel disease. The aim of this study was to perform a national survey to determine the prevalence of inflammatory bowel disease among patients with inherited disorders of coagulation.

METHODS

Using a postal and telephone questionnaire survey sent to directors of all 129 hemophilia centers in the United Kingdom, the number of patients with inflammatory bowel disease and either hemophilia or von Willebrand's disease was determined. The expected number of cases of inflammatory bowel disease in this population was estimated using published data.

RESULTS

Of 6433 patients with hemophilia and 3129 patients with von Willebrand's disease, 4 cases of Crohn's disease were reported compared with expected 11.97-16.58 cases (standardized morbidity ratio, 0.33-0.24; 95% confidence interval, 0.90-0.01; P < 0.05). Ulcerative colitis also occurred significantly less frequently than expected: 9 observed cases in comparison with expected 19.43-31.35 cases (standardized morbidity ratio, 0.46-0.29; 95% confidence interval, 0.91-0.01; P < 0.025).

CONCLUSIONS

This epidemiological study provides further evidence that thrombosis and vascular occlusion may be important in the pathogenesis of inflammatory bowel disease.

Crohn's disease in the Chinese population. An experience from Hong Kong

PURPOSE

Crohn's disease was extremely rare among Chinese. We reviewed all cases diagnosed as having Crohn's disease during a five-year period.

METHODS

A diagnosis of Crohn's disease was made only if all of the following criteria were fulfilled: 1) clinical symptom(s) and sign(s) compatible with chronic inflammatory bowel disease; 2) exclusion of intestinal infection by repeated stool cultures; 3) macroscopic features of small and/or large intestinal inflammation with skip lesion, stricture, and fistula formation; 4) histologic features of Crohn's disease, i.e., focal lymphoid aggregate, focal cryptitis, and granuloma formation; 5) clinical response to conventional therapy for inflammatory bowel disease.

RESULTS

Fifteen ethnic Chinese patients were diagnosed as having Crohn's disease in this period. All patients had colitis, whereas small intestine inflammation was documented in only 47 percent of patients. Extraintestinal manifestations were uncommon except for arthropathy: ankylosing spondylitis (2), sacroiliitis (1), juvenile rheumatoid arthritis (1), and colitic arthritis (1). The majority of our patients responded to medical therapy. Surgery was undertaken in 33 percent of patients.

CONCLUSION

Although there is a general increased incidence of Crohn's disease in the Western world, we too are beginning to see more cases in the Far East. Nevertheless, gastrointestinal infection with bacteria and/or parasites should still be carefully excluded in these countries.

Inflammatory bowel disease in older patients

The onset of UC and CD may occur later in life. Although making the diagnosis of IBD in the elderly can be challenging, the clinical course, natural history, and response to treatment are similar for older and younger patients. In fact, both UC and CD tend to be less extensive in older patients, a feature that may contribute to the overall favorable prognosis for elderly patients with IBD. Overall mortality rates for both UC and CD appear to be similar to that of the general population except for those few patients that present with severe initial disease. Typical features of IBD in the elderly are summarized in Table 3. The differential diagnosis of IBD in the elderly includes infectious causes of enterocolitis, ischemic colitis, and diverticular disease as well as several other mimics of IBD. Awareness of the possibility of late-onset disease and the unique manifestations of disease in the elderly contributes to accurate diagnosis and timely 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.

Survival and causes of death in patients with inflammatory bowel disease: a population-based study

Relative survival up to December 31, 1986 was analyzed for all patients diagnosed with ulcerative colitis (UC) (n = 2,509) and Crohn's disease (CD) (n = 1,469) within the Uppsala Region, Sweden 1965-1983. After 10 years survival was 96% of that expected for UC and CD. Patients with ulcerative proctitis, left-sided colitis, and pancolitis at diagnosis had relative survival rates of 98%, 96%, and 93% respectively. Survival did not differ by extent at diagnosis for patients with CD. After including prevalent cases, 684 deaths occurred compared with 481.1 expected deaths [standardized mortality ratio (SMR) = 1.4; 95% confidence interval (CI) = 1.3-1.5]. Inflammatory bowel disease was the main reason for this excess mortality. Colorectal cancer increased mortality (50 deaths observed vs. 15.2 expected). Death from other cancers were not greater than expected. Obstructive respiratory diseases, especially bronchitis, emphysema, and asthma increased mortality SMR = 1.5 (95% CI = 1.1-2.2) in UC. Cerebrovascular disease mortality occurred less often than expected (SMR = 0.7; 95% CI = 0.5-1.0). Mortality for other diseases and groups of diseases was close to that expected.

Crohn's disease in the northeastern and northern Isles of Scotland: an epidemiological review

An epidemiological study of Crohn's disease has been conducted in northeastern Scotland since 1955 and in the Orkney and Shetland Islands since 1966 through the end of 1988. There were 856 verified cases on the mainland and 58 in the northern isles. There has been no change in the sex ratio on the mainland in recent years, with 63% of patients female. Younger men and women living in the city of Aberdeen are more liable to develop Crohn's disease than rural inhabitants; the reverse is true for men over 60 years of age. The annual incidence of new cases has increased; within the city of Aberdeen it was 11.6 per 100,000 during 1985-1987. The point prevalence on December 31, 1988, for northeastern Scotland was 147 per 100,000. Family histories of the disease were noted in 8.3% of cases. The disease now affects more distal parts of the intestinal tract. There is no clear correlation between these changes and variations in the environment or lifestyle of the population. In the Orkney Islands the overall incidence was 6.1 per 100,000, and there was a male preponderance. In the Shetland Islands the incidence was 5.7 per 100,000 during 1966-1988. A family history of Crohn's disease was more common in the northern islands than on the mainland.

Data management of an inflammatory bowel disease registry

The history and etiology of inflammatory bowel disease which is characterized by two major disease processes: ulcerative colitis and Crohn's disease, remain unknown. Research is focussing on seven major areas of genetic, environmental and physiologic factors that apparently relate to this disease. Based on this background, a population based Inflammatory Bowel Disease Registry was established in 1987 in the Lehigh Valley area of southeastern Pennsylvania. Consent forms, patient data forms and protocols for operation and implementation were developed, and databases were designed to accommodate demographic, basic history, follow-up and relative history data. The databases were correlated with an IBD registry ID number which both enabled relational analyses and ensured confidentiality of data information. The registry continues to grow, providing feedback for both continued medical research and supportive information for IBD patients and their physicians.

Epidemiology of Crohn's disease in Sicily: a hospital incidence study from 1987 to 1989. "The Sicilian Study Group of Inflammatory Bowel Disease"

An epidemiologic study of Crohn's disease was carried out in the Province of Palermo, Italy, between 1987 and 1989. The incidence of first hospitalization was prospectively evaluated in this period. A total of 103 patients (59 males, 44 females) were diagnosed. The standardized annual incidence was 2.7/100,000. The incidence was quite constant during the 3 years of the study (1987: 2.9/100,000; 1988: 2.4/100,000; 1989: 2.99/100,000). Incidence rates were slightly higher in men than in women. The disease had a bimodal age distribution in female (with peaks at age 20-29 and 60-69) and males (with peaks at age 30-39, 40-49). No cases were observed at age 0-9. The incidence of Crohn's disease in southern Italy is comparable to that reported in northern Europe.

The incidence of Crohn's disease is not decreasing in Sweden

An epidemiologic study of the incidence of Crohn's disease during the 25-year period 1963-1987 within a geographically well defined area has been performed. The mean annual incidence during the 25 years was 6.1/10(5) inhabitants. During the first quinquennium the incidence was 4.3/10(5) inhabitants, but during the next four quinquennia the incidence was very stable around 6.6/10(5) inhabitants. The point prevalence on 31 December 1987 was 146/10(5), with a male to female ratio of 1:1.15. An analysis of birth cohorts could not reveal any cohort more prone to develop the disease. Of the 246 incidence cases 5 patients had died of Crohn's disease. The percentage of small-bowel disease only was very stable during the whole study period. The proportion of large-bowel disease decreased only slightly, and combined small- and large-bowel disease increased somewhat towards the end of the study period, probably because of better diagnostic methods.

The epidemiology of inflammatory bowel disease: a large, population-based study in Sweden

Previous population-based incidence studies of inflammatory bowel disease are limited by small numbers, short duration, or inadequate case-finding. To address these problems, we identified all persons with confirmed ulcerative colitis (n = 2509) or Crohn's disease (n = 1469) in the Uppsala Health Care Region from 1965 to 1983. Age-specific incidence rates by sex were slightly greater for males with ulcerative colitis and females with Crohn's disease. Incidence rates for ulcerative colitis and Crohn's disease were higher in urban than rural areas. The annual incidence rate of ulcerative colitis increased from less than 7 per 100,000 to more than 12 per 100,000 during the study period, while the rate for Crohn's disease remained between 5 and 7 per 100,000. The increase in the incidence of ulcerative colitis was the result of a marked increase in the number of patients with ulcerative proctitis. Analyses by 5-year birth cohorts suggest that those born from 1945 through 1954 were at higher risk for ulcerative colitis and Crohn's disease, and that this effect was accounted for by those born in the first half of the year. The seasonality in the cohort effect, combined with the urban preponderance of disease, suggests that environmental causes may be involved in ulcerative colitis and Crohn's disease.

Crohn's disease in the city of Derby, 1951-85

An epidemiological survey of Crohn's disease in the city of Derby showed that the incidence of the condition increased from 0.7/10(5) per year between 1951 and 1955 to 6.67/10(5) per year between 1981 and 1985 but seemed to reach a plateau between 1976 and 1985. Large bowel Crohn's disease was more common in patients presenting aged 60-79 years than in those aged 20-39 years. The increase in incidence was not solely due to the detection of milder disease. There was no evidence that the Asian (Indian subcontinent) population of Derby was resistant to the development of Crohn's disease.

Hospital discharges for inflammatory bowel disease. Time trends from England and the United States

The present study analyzes time trends of inflammatory bowel disease (IBD) in England-Wales and the United States based on nationwide hospitalization statistics. Because these statistics cover the total population of each country, they may give a more representative picture of the true trends than previous analyses concerning only one region or health center. The Hospital In-patient Enquiry was used to evaluate time trends in England-Wales from 1962 to 1985, data from the National Hospital Discharge Survey and the Commission on Professional Activities were used for trends in the United States from 1970 to 1987. A rise of Crohn's disease persisted unabated in the old age groups throughout the observation period. It was less marked in those aged under 35 and reached a plateau during the most recent decade. In ulcerative colitis, discharge rates increased in the older age groups, but remained constant or declined in the middle or younger age groups, respectively. Similar trends were observed in all three surveys. The hospitalization data confirm similar age-specific trends of mortality. The difference between younger and older age groups suggests that generations born 60-80 years ago have become more likely to be affected by IBD leading to hospitalization and mortality. As these high-risk generations grow older, there is a relative rise of hospitalization and mortality from IBD in these subjects.

Epidemiology of Crohn's disease in western Norway. Study group of Inflammatory Bowel Disease in Western Norway

The incidence of Crohn's disease in western Norway was estimated in a prospective epidemiologic study during the years 1984 and 1985. The total population in the area was 807,000. Both inpatients and outpatients were included. Five hundred and fifty general practitioners and 12 hospitals participated in the study. A total of 86 patients were diagnosed, giving a mean annual incidence of 5.3 per 100,000. For patients between 15 and 19 years of age-specific incidence rate was 16.0 The M/F sex ratio was 0.9. In the same period 240 patients with ulcerative colitis were diagnosed (mean annual incidence, 14.8 per 100,000), giving a ratio of 2.8 between ulcerative colitis and Crohn's disease and an annual incidence of 20.1 per 100,000 for inflammatory bowel disease. Familial occurrence of IBD was found for 12% of the patients.

Disability from inflammatory bowel disease among employees in West Germany

The statistics of the German social security system were used to analyse the epidemiology of inflammatory bowel disease (IBD) in Germany and to assess its impact on disability. Patients granted disability pension for IBD were compared with a control group of patients disabled from other causes. Crohn's disease and ulcerative colitis led to disability in significantly younger patients than other diseases. Disability from Crohn's disease was 2.0-fold more common in women than men (95% confidence interval: 1.8-2.3), while disability from ulcerative colitis was similar in both sexes. White collar employees were affected by both diseases more frequently than blue collar employees, the ratio being 1.3 (1.2-1.5) in Crohn's disease and 1.6 (1.4-1.8) in ulcerative colitis. Although IBD is relatively rare, it has severe socioeconomic implications, because compared with other diseases, predominantly young age groups become disabled.

Hospital incidence of Crohn's disease in the province of Palermo. A preliminary report

The hospital incidence of Crohn's disease in the province of Palermo was studied from January 1987 to June 1988. A total of 51 patients (34 in 1987 and 17 in the first half of 1988) were diagnosed. The incidence rate calculated for the 1st year was 2.7/100,000. A similar figure was observed in the first 6 months of 1988, which ought to rule out an overestimation in the 1st year. These preliminary data suggest that the incidence of Crohn's disease in southern Italy is similar to that reported in northern Europe.

Development of an inflammatory bowel disease registry

Inflammatory Bowel Disease is characterized by two major entities, Crohn's Disease and Ulcerative Colitis. These bowel diseases have associated problems involving the eyes, joints, skin, kidneys, immunological system, hepatobiliary system, and psychiatric disturbances. A regional IBD registry encompassing 18 hospitals and IBD specialists in east/northeast Pennsylvania was established to promote awareness of the clinical and epidemiological aspects of the disease. Results of this data collection effort will be shared with patients and physicians through the use of newsletters and symposia. A Basic History (HX) form, an Operative Data (OR) form, and an Annual Follow-up (FU) form was used to collect relevant data. Participation is voluntary and all information is confidential.

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

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

Crohn's disease of late onset in Blackpool

Fifty five (26%) of two hundred and fifteen patients presenting with Crohn's disease in the Blackpool area over a 15 year period (1969-1983) were over 60 years of age. There were twice as many women as men (38:17). In 60% disease was limited to the large bowel compared to only 29% in the younger age group. Many of these were women with mild distal colitis. Twenty one patients required operative management. In general, the prognosis was good in colonic disease, but in small bowel and ileocolonic disease the necessity for early operative intervention was potentially fatal. Delayed diagnosis, poor nutritional state and associated disease were relevant adverse factors. The majority of patients at the time of review were well and, where necessary, were coping satisfactorily with a stoma.

Monozygotic triplets with Crohn's disease of the colon

Female monozygotic triplets all developed Crohn's disease within a period of 11 mo. The monozygosity was demonstrated by analysis of 24 genetic markers of different chromosomal localization. Crohn's disease was diagnosed using clinical, radiologic, and endoscopic findings. Histologic evaluation of bowel tissue was consistent with Crohn's disease. All 3 patients had colon involvement; the terminal ileum appeared normal. The patient in whom Crohn's disease was first diagnosed had the severest course. Our observations support the role of a genetic influence in the manifestation of Crohn's disease. Nevertheless, environmental factors or microorganisms, or both, have to be taken into account, perhaps as factors promoting the outbreak of Crohn's disease.

Incidence of Crohn's disease in a defined population in northern Sweden, 1974-1981

An epidemiologic study of Crohn's disease, comprising the population of the two most northerly counties of Sweden and covering the 8-year period 1974-1981, was carried out. The basic population was about 510,000, and the area is regarded as rural, with a mean density of 3 inhabitants per km2. In all, 199 patients with a hospital discharge diagnosis of Crohn's disease were identified. A mean annual incidence of 4.9 per 10(5) inhabitants and a peak incidence of 6.7 were found. There was no sex difference and no obvious change in incidence during the time period studied. The highest incidence was observed in young adults, and ileal disease predominated. A significantly higher incidence was observed in the town of Umeå than in the rest of northern Sweden. The increase was confined to the ages between 20 and 40 years. The present study concludes that the incidence of Crohn's disease is high in northern Sweden, even though it is a sparsely populated rural area. The incidence figures are similar to those obtained for other parts of Sweden.