Ulcerative colitis and indeterminate colitis in the city of Malmö, Sweden. A 25-year incidence study

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.

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.

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.

Diagnostic value of anti-Saccharomyces cerevisiae and antineutrophil cytoplasmic autoantibodies in inflammatory bowel disease

OBJECTIVES

Correct diagnosis of inflammatory bowel disease (IBD), especially the differentiation between Crohn's disease (CD) and ulcerative colitis (UC), is highly important toward treatment and prognosis. Serological markers are noninvasive diagnostic tools that could be of value in differentiating CD from UC, in cases of indeterminate colitis, and in the identification of subgroups in IBD. The aim of this study was to evaluate the diagnostic accuracy of perinuclear antineutrophil cytoplasmic (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) for IBD.

METHODS

ASCA and pANCA were studied in a large cohort of consecutive IBD patients (n = 582: 407 CD, 147 UC, and 28 indeterminate colitis), patients with non-IBD diarrheal illnesses (n = 74), and healthy controls (n = 157). An indirect immunofluorescence technique and a standardized ELISA were performed for detection of pANCA and ASCA, respectively.

RESULTS

Prevalence of ASCA and pANCA was high in CD patients (59.7%) and UC (49.7%) patients, respectively. Positivity for both markers was significantly lower in healthy and non-IBD controls. Accuracy data (sensitivity, specificity, PPV, and NPV, respectively) for differentiating IBD from controls are as follows: ASCA+: 60% (243/407), 91% (345/378), 88% (243/276), and 68% (345/509); pANCA+: 50% (73/147), 95% (605/638), 69% (73/106), and 89% (605/679); ASCA+/pANCA-: 56% (229/407), 94% (355/378), 91% (229/252), and 67% (355/533); and pANCA+/ASCA-: 44% (65/147), 97% (620/638), 78% (65/83), and 88% (620/702).

CONCLUSIONS

Specificity of serological markers for IBD is high, but low sensitivity makes them less useful as diagnostic tests. The combination of tests is probably more powerful, although, clinical subgroups still need to be defined. The usefulness of these markers in indeterminate colitis needs to be studied prospectively.

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.

The natural history of ulcerative proctitis: a multicenter, retrospective study. Gruppo di Studio per le Malattie Infiammatorie Intestinali (GSMII)

OBJECTIVE

The aim of this study was to evaluate the clinical features and the long term evolution of patients with a well defined initial diagnosis of ulcerative proctitis.

METHODS

Patients with an original diagnosis of ulcerative proctitis who had been seen at any of 13 institutions from 1989 to 1994 were identified. Data on disease onset and subsequent evolution were recorded. In addition, 575 patients with more extensive disease, treated in the same centers, were used as controls.

RESULTS

A total of 341 patients satisfied the inclusion criteria. The percentage of smokers in these patients was slightly lower than in controls; no differences were found in the other clinical/demographic variables evaluated. A total of 273 patients entered long term follow-up (mean, 52 months). Proximal extension of the disease occurred in 74 of them (27.1%). The cumulative rate of proximal extension and of extension beyond the splenic flexure was 20% and 4% at 5 yr and 54% and 10% at 10 yr, respectively. The risk of proximal extension was higher in nonsmokers, in patients with >3 relapses/yr, and in patients needing systemic steroid or immunosuppressive treatment. Refractory disease was confirmed as an independent prognostic factor at multivariate analysis.

CONCLUSIONS

Proximal extension of ulcerative proctitis is frequent and may occur even late after the original diagnosis. However, the risk of extension beyond the splenic flexure appears to be quite low. Smoking seems to be a protective factor against proximal extension, whereas refractoriness is a risk factor for proximal extension of the disease.

Inflammatory bowel disease in Iceland, 1980-89. A retrospective nationwide epidemiologic study

BACKGROUND

A previous nationwide epidemiologic study of inflammatory bowel disease (IBD) in Iceland in 1950-79 showed a low but steadily rising incidence. The incidence of IBD in Iceland in 1980-89 was investigated and compared with reports from neighboring countries.

METHODS

Cases were retrieved by a review of all small- and large-intestinal tissue specimens with any type of inflammation submitted to the only two departments of pathology in Iceland. All small-intestinal X-ray records suggestive of Crohn's disease (CD) in the three major hospitals were also screened. All hospital and outpatient records of cases suggestive of IBD were then reviewed using accepted criteria for confirmation or exclusion.

RESULTS

The mean annual incidence of ulcerative colitis (UC) was 11.7/100,000, and that of CD 3.1/100,000. The highest age-specific incidence of UC was in the group 30-39 years old and for CD in the group 60-69 years old. The most frequent involvement at diagnosis of UC was proctitis only, in 54%, and in CD colon only, in 54.7% of the patients.

CONCLUSIONS

This study shows a continuing increase in the incidence of both diseases. Compared with the period 1970-79, there has been an almost twofold increase in the mean annual incidence of UC and more than a threefold increase of CD, a statistically significant increase in both instances.

High incidence of inflammatory bowel disease in The Netherlands: results of a prospective study. The South Limburg IBD Study Group

PURPOSE

To gain recent epidemiologic information about inflammatory bowel disease in The Netherlands, a prospective study over four years (1991-1995) was performed.

METHODS

The incidence of inflammatory bowel disease and its subgroups was examined using standardized reports of newly diagnosed patients. A separate study compared the Inflammatory Bowel Disease Registration and computerized diagnostic files of a subgroup of general practitioners with the aim of estimating completeness of case ascertainment.

RESULTS

The following mean incidence rates (per 100,000 inhabitants and year) were found: 6.9 (95 percent confidence interval, 5.9-7.9) for Crohn's disease, 10 (95 percent confidence interval, 8.7-11.2) for ulcerative colitis (23 percent of these with ulcerative proctitis), and 1.1 (95 percent confidence interval, 0.7-1.5) for indeterminate colitis. In the age category 20 to 29 years, the incidence rate of Crohn's disease with small-bowel involvement was higher in females than in males. In extended ulcerative colitis, a male preponderance was observed in the older age groups. Estimated case ascertainment was 78 percent.

CONCLUSIONS

Compared with recent studies in neighboring countries, the observed age and gender standardized incidence rates are high in the south of The Netherlands. Completeness of case ascertainment might have contributed to this observation; however, case ascertainment was low in ulcerative proctitis. In the study area, differences in age and gender standardized incidence rates and in disease localizations could be compatible with an influence of environmental risk factors.

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.

Risk of relapse in new cases of ulcerative colitis and indeterminate colitis

PURPOSE

Changes in morbidity pattern of ulcerative colitis have created a need to update understanding of the course of the disease.

METHOD

A follow-up study was done of relapse rates and progression of inflammation in 571 non-selected patients with ulcerative and indeterminate colitis.

RESULTS

Relapse rate ten years after diagnosis was 70 percent in definite ulcerative colitis, 22 percent in probable ulcerative colitis, and 77 percent in indeterminate colitis. During the study period, there was no change in the relapse rate. In relapsing proctitis, 52 percent developed more extensive inflammation. Fifty-four percent of patients with only one attack of colitis had persistent signs of inflammatory bowel disease.

CONCLUSIONS

Shift in morbidity pattern to a greater proportion of patients with proctitis at diagnosis and a shorter time from onset of symptoms to diagnosis had no influence on the relapse rate. Indeterminate colitis has a worse prognosis than definite ulcerative colitis. Considering the documented efficacy of sulfasalazine, the high relapse rate calls for studies of the effectiveness of such treatment in everyday practice.

Incidence of colorectal cancer and all cause mortality in non-selected patients with ulcerative colitis and indeterminate colitis in Malmö, Sweden

Cancer morbidity and all cause mortality were studied prospectively in all patients with definite and probable ulcerative colitis and indeterminate colitis diagnosed from 1958 to 1982, in the city of Malmö, Sweden. The follow-up to Jan. 1, 1990 was complete for all but ten patients. Nine of the 471 patients with ulcerative colitis and three of the 100 patients with indeterminate colitis developed colo-rectal cancer. The incidence of colorectal cancer in ulcerative colitis was 1.4 per 1000 person-years. The observed number of cases was 2.1 times higher than expected; (95% C.I. 1.0-4.1), based on the age- and sex-specific cancer incidence in the city during the study period. Indeterminate colitis was associated with a higher colorectal cancer risk than ulcerative colitis; 2.4 per 1000 person-years; (SMR 8.6, 95% C.I. 1.8-25.1). Both conditions were associated with a slight increased mortality rate, for ulcerative colitis 12.6 per 1000 person-years; (SMR 1.3, 95% C.I. 1.0-1.5), and for indeterminate colitis 11.7 per 1000 person-years; (SMR 2.7, 95% C.I. 1.6-4.4). Complications of colitis were the main cause of death in both groups. The cancer risk was related to extent of disease, duration of disease and female gender. Ten out of the 12 cases with cancer had or developed total colitis. However, only seven of the 134 cases with total ulcerative colitis and two of 87 cases with total indeterminate colitis developed cancer.(ABSTRACT TRUNCATED AT 250 WORDS)