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PubMed1999

Cancer risk in collagenous colitis.

Collagenous colitis is a recently described form of chronic inflammatory bowel disease. Other inflammatory bowel disorders are associated with increased risk of colorectal and extracolonic malignancies, but this has not been evaluated in collagenous colitis. Colorectal and extracolonic malignancies were identified in 117 patients with collagenous colitis from the Johns Hopkins Registry. The incidence rates of identified tumors, overall incidence rate of tumors, and overall mortality were then compared with general population through person year analysis with adjustment for population. No cases of colorectal cancer were found in collagenous colitis patients during a mean follow-up period of 7.0 years (range 2-12 years) after the diagnosis of colitis. Two patients developed colorectal cancer prior to the diagnosis of colitis, but no increase in life-time relative risk of colorectal cancer was found (relative risk 0.52; 95% confidence limits 0.05-1.5). An increased relative risk of lung cancer in women (relative risk 3.7; 95% confidence limits 1.0-9.6; p = 0.048) was noted. The relative risk of overall malignancy and overall mortality was not different than the general population. In collagenous colitis patients the life-time relative risk of colorectal cancer and the relative risk after the diagnosis of colitis with a mean observation period of 7 years was not increased. An increase in relative risk of lung cancer in women with collagenous colitis argues for further investigation of the role of smoking and other factors in this disorder.

Age Distribution↗
PubMed2003

Reported incidence of occupational asthma in France, 1996-99: the ONAP programme.

AIMS: To estimate the general and specific incidence of occupational asthma in France in 1996-99; and to describe the distribution of cases by age, sex, suspected causal agents, and occupation. METHODS: New cases of occupational asthma were collected by a national surveillance programme, based on voluntary reporting, named Observatoire National des Asthmes Professionnels (ONAP), involving a network of occupational and chest physicians. For each case, the reporting form included information on age, sex, location of workplace, occupation, suspected causal agent, and methods of diagnosis. Estimates of the working population, used to calculate incidence rates by age, sex, region, and occupation, were obtained from the Institut National de la Statistique et des Etudes Economiques (INSEE) and from the French Securite Sociale statistics. RESULTS: In 1996-99, 2178 cases of occupational asthma were reported to the ONAP, giving a mean annual rate of 24/million. Rates in men were higher than rates in women (27/million versus 19/million). The highest rate was observed in the 15-29 years age group (30/million). The most frequently incriminated agents were flour (20.3%), isocyanates (14.1%), latex (7.2%), aldehyde (5.9%), persulphate salts (5.8%), and wood dusts (3.7%). The highest risks of occupational asthma were found in bakers and pastry makers (683/million), car painters (326/million), hairdressers (308/million), and wood workers (218/million). CONCLUSION: Despite likely underreporting, the number of cases of occupational asthma reported to the ONAP was approximately twice the number of compensated cases over the same period. The relevance of the programme is confirmed by the reproducibility of the results year after year, and its consistency with other surveillance programmes. The ONAP programme is useful for the identification of targets for primary prevention.

Adolescent↗
PubMedDate not supplied

Posterior predictive model checks for disease mapping models.

Disease incidence or disease mortality rates for small areas are often displayed on maps. Maps of raw rates, disease counts divided by the total population at risk, have been criticized as unreliable due to non-constant variance associated with heterogeneity in base population size. This has led to the use of model-based Bayes or empirical Bayes point estimates for map creation. Because the maps have important epidemiological and political consequences, for example, they are often used to identify small areas with unusually high or low unexplained risk, it is important that the assumptions of the underlying models be scrutinized. We review the use of posterior predictive model checks, which compare features of the observed data to the same features of replicate data generated under the model, for assessing model fitness. One crucial issue is whether extrema are potentially important epidemiological findings or merely evidence of poor model fit. We propose the use of the cross-validation posterior predictive distribution, obtained by reanalyzing the data without a suspect small area, as a method for assessing whether the observed count in the area is consistent with the model. Because it may not be feasible to actually reanalyze the data for each suspect small area in large data sets, two methods for approximating the cross-validation posterior predictive distribution are described.

Algorithms↗
PubMed2004

Small area variations of cancer mortality in Hong Kong--the roles of health care and socio-economic status.

Variations of cancer incidence and cancer mortality across small areas in Hong Kong were explored and attempt made to link them to socio-economic differences. The entire Hong Kong population during the period 1984-88 was divided into 65 small areas. The geographic distributions of incidence and mortality for ten most frequent sites of cancers (6 male and 4 female) were analyzed by separating the systematic variance from the random variance. A Poisson regression model was fitted for each cancer using the standardized incidence ratio (SIR) as a covariate for mortality. The geographic variations in SIR for the individual cancers were, in turn, analyzed similarly using a socio-economic score as the covariate. We found a statistically significant systematic variance in mortality for all six male cancers and three of the four female cancers studied. More than 50% of the systematic variance of mortality for nine cancers could be explained by the geographic variations in incidence, suggesting that other factors, like the provision and/or outcomes of health care services, played a minor role. There were statistically significant systematic variances in SIR for all male and female cancers. The socio-economic score accounted for over 50% of the systematic variance for three cancer sites. This study illustrated an approach to explore underlying explanations for the geographic variations of disease incidence and mortality. As more aggregate exposure data become available at the small area level, this type of ecological analysis would help in delineating the contributions of various factors and guide investigators in their search for the etiology background of diseases.

Female↗
PubMed2006

Force distribution in a randomly perturbed lattice of identical particles with 1/r2 pair interaction.

We study the statistics of the force felt by a particle in the class of a spatially correlated distribution of identical pointlike particles, interacting via a 1/r2 pair force (i.e., gravitational or Coulomb), and obtained by randomly perturbing an infinite perfect lattice. We specify the conditions under which the force on a particle is a well-defined stochastic quantity. We then study the small displacements approximation, giving both the limitations of its validity and, when it is valid, an expression for the force variance. The method introduced by Chandrasekhar to find the force probability density function for the homogeneous Poisson particle distribution is extended to shuffled lattices of particles. In this way, we can derive an approximate expression for the probability distribution of the force over the full range of perturbations of the lattice, i.e., from very small (compared to the lattice spacing) to very large where the Poisson limit is recovered. We show in particular the qualitative change in the large-force tail of the force distribution between these two limits. Excellent accuracy of our analytic results is found on detailed comparison with results from numerical simulations. These results provide basic statistical information about the fluctuations of the interactions (i) of the masses in self-gravitating systems like those encountered in the context of cosmological N -body simulations, and (ii) of the charges in the ordered phase of the one-component plasma, the so-called Coulomb or Wigner crystal.

Journal Article↗
PubMed2003

Causes of death in patients with celiac disease in a population-based Swedish cohort.

BACKGROUND: Patients with celiac disease have an increased risk of death from gastrointestinal malignancies and lymphomas, but little is known about mortality from other causes and few studies have assessed long-term outcomes. METHODS: Nationwide data on 10 032 Swedish patients hospitalized from January 1, 1964, through December 31, 1993, with celiac disease and surviving at least 12 months were linked with the national mortality register. Mortality risks were computed as standardized mortality ratios (SMRs), comparing mortality rates of patients with celiac disease with rates in the general Swedish population. RESULTS: A total of 828 patients with celiac disease died during the follow-up period (1965-1994). For all causes of death combined, mortality risks were significantly elevated: 2.0-fold (95% confidence interval [CI], 1.8-2.1) among all patients with celiac disease and 1.4-fold (95% CI, 1.2-1.6) among patients with celiac disease with no other discharge diagnoses at initial hospitalization. The overall SMR did not differ by sex or calendar year of initial hospitalization, whereas mortality risk in patients hospitalized with celiac disease before the age of 2 years was significantly lower by 60% (95% CI, 0.2-0.8) compared with the same age group of the general population. Mortality risks were elevated for a wide array of diseases, including non-Hodgkin lymphoma (SMR, 11.4), cancer of the small intestine (SMR, 17.3), autoimmune diseases (including rheumatoid arthritis [SMR, 7.3] and diffuse diseases of connective tissue [SMR, 17.0]), allergic disorders (such as asthma [SMR, 2.8]), inflammatory bowel diseases (including ulcerative colitis and Crohn disease [SMR, 70.9]), diabetes mellitus (SMR, 3.0), disorders of immune deficiency (SMR, 20.9), tuberculosis (SMR, 5.9), pneumonia (SMR, 2.9), and nephritis (SMR, 5.4). CONCLUSION: The elevated mortality risk for all causes of death combined reflected, for the most part, disorders characterized by immune dysfunction.

Adolescent↗
PubMed1998

Young-onset Parkinson's disease revisited--clinical features, natural history, and mortality.

The authors report on clinical features and mortality rates in a group of 149 patients with apparent idiopathic parkinsonism starting before the age of 40 years. Ten had juvenile parkinsonism (JP; onset before age 21 years) and 139 had young-onset Parkinson's disease (YOPD; onset at age 21 to 40 years). Included were 60 patients originally reported 10 years ago. Fifty percent of the JP group had a positive family history of parkinsonism in a first-degree relative, and clinical presentation was heterogeneous. Mortality risk was threefold that of the normal population. In the YOPD group, the mortality risk was double that of the normal population. Poor initial response to L-dopa was a risk factor for early death. In two previously reported patients, the diagnosis had been changed to multiple system atrophy and Machado-Joseph disease. After a median disease duration of 18 years, cognitive impairment was found in only 19% of YOPD patients (13% of those younger than 60 years and 43% of those 60 years or older). Age was the most important factor for development of dementia, but female sex and positive family history of parkinsonism also had more modest predictive value. After a disease duration of 10 years or less, only 5% of patients were experiencing falls and 30% freezing, but all patients had developed L-dopa-related fluctuations and dyskinesias. The authors conclude that the mortality rate in parkinsonism starting before the age of 40 is increased in comparison to the normal population and is similar to the general Parkinson's disease population. Intellectual function and postural reflexes are usually well preserved for many years despite a long history of parkinsonism and the early and frequent occurrence of treatment complications, provided the patients remain biologically and chronologically young.

Adolescent↗
PubMed1993

Aggregated distributions in models for patchy populations.

We investigate a model describing immigration, birth, and death of parasites on a dynamic host population. The model can also be interpreted as describing a herbivore population distributed on discrete patches of vegetation. We derive differential equations for the total number of hosts/patches and the mean number of parasites/herbivores per host/patch. The equations explicitly involve the variance-to-mean ratio of the distribution. It is shown that the positive equilibrium is stable if and only if the variance-to-mean ratio as a function of the mean increases with increasing mean. Thus aggregation of the parasites alone is not sufficient to stabilize the system; it is rather the density-dependent increase in parasite mortality due to a higher aggregation at higher mean parasite loads that causes stability. From this it follows that introducing a distribution with a constant clumping parameter into the model artificially stabilizes the steady state. We derive a three-dimensional model based on an assumption about the form of the distribution of the parasites on the hosts, but without introducing additional parameters into the model. We compare stability results for this model for different types of aggregated distributions and show that the underlying distribution determines the qualitative results about the stability of the equilibrium.

Animals↗
PubMed2005

Hartmann's colectomy and reversal in diverticulitis: a population-level assessment.

PURPOSE: This study was designed to assess the costs and outcomes of colostomy and colostomy reversal in patients with diverticulitis and examine the impact of such procedures on the health care system. METHODS: We employed a retrospective design and used a Washington State administrative database to identify patients undergoing operations with colostomy (1987-2002) who were followed over time. Descriptive and comparative analysis was performed, focusing on patients with diverticulitis. RESULTS: There were 16,556 patients who underwent colostomy and 5,420 (32.7 percent) were for diverticulitis and its related complications (mean age, 64.8 +/- 15.1 years; 53.2 percent female). In patients with diverticulitis, the rate of colostomy reversal was 56.3 percent (80 percent in patients less than 50 years, and 30 percent in patients over 77 years). The in-hospital mortality rate after colostomy reversal was 0.36 percent, and was 2.6 percent in those over 77 years of age. After colostomy reversal a second stoma was used in 3.4 percent, reoperation was required for bleeding complications in 0.6 percent, and infectious complications were noted in 2 percent. The length of time from colostomy to its reversal was approximately five months (138.1 +/- 164 days; interquartile range, 72-156). The relationship between the length of time from colostomy to reversal was evaluated and the adjusted odds of a second stoma being used at the time of colostomy reversal were 45 percent higher (odds ratio, 1.45; 95 percent confidence interval, 1.22, 1.73) for each increase in time interval (<3, 6-9, 9-12, >12 months). CONCLUSIONS: One-third of all colostomies were related to diverticulitis and only 56 percent were reversed. We identified a higher than expected mortality rate among older patients undergoing colostomy reversal. The impact of colostomy and reversal operations on both patients and the health care system is significant.

Adolescent↗
PubMed2006

Emergency department visits for behavioral and mental health care after a terrorist attack.

STUDY OBJECTIVE: We assess emergency department (ED) utilization by a population whose health care encounters can be tracked and quantified for behavioral and mental health conditions in the aftermath of the terrorist attacks of September 11, 2001. METHODS: We assessed presentations to EDs by using Medicaid analytic extract files for adult New York State residents for 2000 and 2001. We created 4 mutually exclusive geographic areas that were progressively more distant from the World Trade Center and divided data into 4 periods. All persons in the files were categorized by their zip code of residence. We coded primary ED diagnoses for posttraumatic stress disorder, substance abuse, psychogenic illness, severe psychiatric illness, depression, sleep disorders, eating disorders, stress-related disorders, and adjustment disorders. RESULTS: There was a 10.1% relative temporal increase in the rate of ED behavioral and mental health diagnoses after the September 11, 2001, terrorist attacks for adult Medicaid enrollees residing within a 3-mile radius of the World Trade Center site. Other geographic areas experienced relative declines. In population-based comparisons, Medicaid recipients who lived within 3 miles of the World Trade Center after the September 11, 2001, terrorist attacks had a 20% increased risk of an ED mental health diagnosis (prevalence density ratio 1.2; 95% confidence interval 1.1 to 1.3) compared to those who were non-New York City residents. CONCLUSION: The complex role that EDs may play in responding to terrorism and disasters is becoming increasingly apparent. To the best of our knowledge, this is the first report of a quantifiable increase in ED utilization for mental health services by persons exposed to a terrorist attack in the United States.

Adult↗
PubMed2000

Invasive disease due to group B Streptococcus in pregnant women and neonates from diverse population groups.

From 1993 through 1996, surveillance for invasive disease due to group B Streptococcus (GBS) in neonates aged <7 days and in peripartum pregnant women was performed in a racially and ethnically diverse cohort in 4 cities in the United States. In a birth population of 157,184, 130 neonatal cases (0.8 per 1000) and 54 maternal cases (0.3 per 1000) were identified. Significant correlates with neonatal disease were black or Hispanic race and a birth weight <2500 g. The attack rate for peripartum maternal infection varied widely by city and may have been influenced by the frequency of administration of intrapartum antibiotics or of evaluating febrile women by performance of blood cultures. Pregnancy loss or GBS disease in the infant occurred in 28% of these maternal cases. Among neonatal and maternal GBS isolates, serotypes Ia (34%-37%) and III (25%-26%) predominated, and type V was frequent (14%-23%). These results provide a description of invasive GBS perinatal infection during the period in which guidelines for prevention were actively disseminated.

Age Distribution↗
PubMed2002

Temporal trends in the incidence of human immunodeficiency virus infection and risk behavior among injection drug users in Baltimore, Maryland, 1988-1998.

Although the incidence of and mortality from acquired immunodeficiency syndrome have declined recently in the United States, data are needed on the incidence of human immunodeficiency virus (HIV) and risk behaviors among injection drug users (IDUs). The authors studied the temporal trends of HIV incidence and risk behavior, ascertained through semiannual confidential interviews, between 1988 and 1998 in a cohort of 1,532 HIV-seronegative IDUs in Baltimore, Maryland. An additional 338 HIV-negative drug users were recruited in 1994 and were studied by using the same methods. Overall, 277 persons seroconverted to HIV during 8,826.45 person-years of follow-up, an incidence of 3.14 per 100 person-years. The incidence per 100 person-years declined over time from 4.45 in 1988-1990 to 3.35 in 1991-1994 to 1.84 in 1995-1998, a decline of 12% per year. HIV infections were associated with injection of cocaine, more frequent injection, needle sharing, and injection in a shooting galley. Sexual behavior variables associated with HIV incidence included a sexually transmitted infection, male homosexual behavior, and sex with another IDU. These data suggest that high-risk behavior and HIV incidence among IDUs have decreased recently in Baltimore. Nevertheless, additional prevention strategies are needed in these populations.

Adult↗
PubMed1997

Change in incidence of Crohn's disease and ulcerative colitis in Denmark. A study based on the National Registry of Patients, 1981-1992.

BACKGROUND: The incidence of inflammatory bowel disease (IBD) in Denmark is considered to be among the highest in Europe. However, the diseases are relatively rare and therefore it would be useful if existing registers could replace ad hoc examination in the surveillance of IBD. METHODS: The present study used the Danish National Registry of Patients to estimate incidence rates, 1981-1992. RESULTS: A total of 2806 patients with Crohn's disease (CD) and 8125 with ulcerative colitis (UC) were identified. The mean incidence for CD was 4.6 (5.4 for women and 3.7 for men) per 100,000 per year, with a peak incidence in younger women. The incidence increased in most age groups with the highest increase in older women. The mean incidence for UC was 13.2 (13.4 for women and 13.0 for men) per 100,000 per year, with the highest incidence in older men. A decreasing tendency in the incidence was present in most age groups. CONCLUSIONS: The present study found an increasing incidence for CD and a stable incidence with a tendency to decrease for UC. Comparison with ad hoc studies indicates that it is possible to use the Danish National Registry of Patients in the surveillance of IBD, especially for CD.

Adult↗
PubMed1999

Incidence of myocardial infarction in the Danish MONICA population 1982-1991.

BACKGROUND: Cardiovascular mortality has been declining in Denmark over the past 20 years. Trends in incidence of myocardial infarction (MI) over the period 1982-1991 are described within the framework of the World Health Organization MONICA Project. METHODS: The DAN-MONICA heart register included all cases of MI in 25-74-year-old men and women living in 11 municipalities around Glostrup County Hospital evolving over a period of 10 years. They were identified retrospectively based mainly on relevant ICD diagnoses in death certificates and hospital discharge reports. Cases meeting WHO-MONICA criteria for definite or possible MI, recurrent as well as first-ever MI, were registered. Subsequent tracing of cases through national registers on deaths and hospitalizations by means of the patient's civil registration number ensured the completeness of the registration. RESULTS: A total of 6025 cases of MI occurred in the period, 4532 among men and 1493 among women. A total of 2923 men and 1047 women had a first-ever MI in the period. The age-standardized rates show a definite decline over the registration period for men and a less distinct decline for women. CONCLUSIONS: The DAN-MONICA heart register meets the requirements for completeness and uniformity throughout the registration period. Causes and magnitude of bias are well described. Even when possible sources of bias are taken into account, the incidence of MI decreased significantly over the 10-year-period 1982-1991 by an average of 5.0% per year for men and 3.5% per year for women.

Adult↗
PubMed1999

Simultaneous modelling of time trends and regional variation in mortality rates.

BACKGROUND: We seek to model the regional component of the variance in the mortality rates in the UK and to ascertain if there is evidence that this regional variance is increasing in recent periods. METHODS: Age Period Cohort (APC) models, based on the local 'curvatures', are used in each region to describe the changes in the trends in the mortality rates. This is extended to a multilevel model to estimate the regional component of the variance in the rates and to estimate the effect of regional differences in the trends in the rates. We show how the use of a multilevel APC model can help to distinguish the cohort and period trends in the mortality rates from the cohort and period effects on the regional variance in these rates. RESULTS: For both sexes, but particularly for females, a reduction in the rate of decrease in mortality was found around 1960. In addition, particularly for females, cohorts born after 1930 appear to show reductions in mortality at an increased rate. It is demonstrated that there is evidence that the between-region variation in the rates has not remained constant and that it is much less now than it was at the beginning of the data series. Further, there is evidence that the trends in the rates are not the same in all regions and that while there is a convergence of the rates in many regions, Scotland, in particular, stands out as a region which contributes most to the regional variation in mortality rates. CONCLUSION: Evidence of regional variation in mortality rates has been found with a suggestion of a decrease over the period of the study though with some stability since 1951.

Adolescent↗
PubMed2000

Comparison of fatal coronary heart disease occurrence based on population surveys in Japan and the USA.

BACKGROUND: Although vital statistics have indicated large Japanese-American differences in mortality rates for coronary heart disease (CHD), the magnitude of difference has not been documented well using comparable validation of cause of death. METHODS: Population-based fatal CHD data were compared between the Oita Cardiac Death Survey, Japan and the Atherosclerosis Risk in Communities (ARIC) Study, USA. Both studies (population: Oita City 198 093; the ARIC comunities 286 820) identified possible fatal CHD events (International Classification of Diseases, Ninth Revision [ICD-9]: 410-414, 250, 401-402, 427-429, 440, and 798-799) among residents aged 35-74 years during 1992-1993. Comparable criteria for classifying cause of death were applied. Sex-specific, age-adjusted mortality rates of CHD were calculated by place of death. RESULTS: In all, 330 deaths in Oita and 1398 in the ARIC communities had eligible ICD-9 death certificate codes; CHD codes (ICD-9 410-414) comprised 30.6% of investigated deaths in Oita and 58.6% in ARIC. For men, the non-validated rate ratio for CHD deaths (ARIC:Oita City) was 5.9 (95% CI : 4.2-8.5), which fell to 4.7 (95% CI : 3.5-6.4) with validation and inclusion of sudden deaths within one hour of onset as fatal CHD. For women, the overall non-validated rate ratio was 4.6 (95% CI : 2.8-7.6), which fell to 3.9 (95% CI : 2.4-6.3) with validation and but there was little further change when the sudden deaths were added. CONCLUSIONS: Our results suggest that differences in fatal CHD rates between Japanese and Americans were not as large as suggested by vital statistics when events were validated and sudden deaths were included.

Adult↗