Descriptive epidemiology of IDDM in Hokkaido, Japan: the Childhood IDDM Hokkaido Registry

OBJECTIVE: To identify the incidence of IDDM with regard to sex, age, family history of diabetes, season, and 5-year period of childhood IDDM among children ages 0-14 years from a population-based epidemiological study in Hokkaido, Japan, from 1973 to 1992. RESEARCH DESIGN AND METHODS: Registration of all new IDDM cases in Hokkaido was conducted by the Childhood IDDM Hokkaido Registry Study Group from 1973 to 1992. The cases were selected from among 1) patients who were admitted to the member hospitals of the study group, 2) patients who answered a questionnaire distributed to hospitals and diabetic clinics throughout Hokkaido, and 3) patients whose cases were recorded in free-treatment medical records of urban and rural districts. The case ascertainment rate was estimated to be 100%. Differences in incidence with regard to sex, age, family history of diabetes, season, and year period were analyzed by the Poisson regression analysis by GENMOD. RESULTS: During the 20-year period studied, 396 cases (181 boys, 215 girls) of abrupt-onset IDDM were registered. Statistically significant differences in annual incidence were found according to sex (female), age (8-14 years), history (having no diabetes in family), season (spring), and 5-year period. CONCLUSIONS: This is the first population-based, long-term epidemiological study of childhood IDDM from Japan. We observed a significantly higher annual incidence (per 100,000/year) of IDDM in female subjects (1.81), older age-groups (2.25 for 8-14 years), subjects with no family history of diabetes (1.26), diabetes onset in the spring (2.20), and an increased trend over the 20 years. In addition, the heterogeneity of IDDM among Japanese children needs to be elucidated.     

Insulin-dependent diabetes in the county of Funen 1970-2020. An epidemiological description

We present an epidemiological model applicable to insulin-dependent diabetes mellitus (IDDM), based on which prevalence rates are estimated from assumed rates of incidence and mortality of diabetes. The model is illustrated by analysing epidemiological data on IDDM in Fyn County, Denmark for the period 1970-1990, with predictions of prevalence rates during 1990-2020. The epidemiological model assumes known prevalence rates as well as incidence rates and mortality at a given point of time. Under assumed rates of incidence and mortality of IDDM and its complications, the prevalence rate is the dependent variable which is estimated as a function of calendar time. We used epidemiological data on IDDM (operationally defined as insulin-treated diabetes with onset before age 30 years), blindness and nephropathy as well as mortality as reported for the years 1973 and 1987 in Fyn County, Denmark. During 1970-1990 the prevalence of IDDM increased steadily, due to increasing incidence and decreasing risk of complications and mortality. The relative prevalence of patients with nephropathy increased whereas that of blind patients decreased considerably. Under specified assumptions regarding the future levels of incidence of disease, complications and of mortality, it is estimated that the prevalence rate of IDDM in the year 2020 will be 45-60% higher than the level in 1990. The relative prevalence of patients with nephropathy will increase further, whereas the relative prevalence of blind patients will remain constant at a low level. We conclude that IDDM will represent an increasing public health problem in Denmark over the next decades, with increasing overall prevalence rates and a rising proportion of patients with nephropathy. The major determinants of this trend are increasing incidence, combined with declining mortality and declining risk of complications. It is recommended that epidemiological modelling techniques be further developed to provide improved data for the planning of the future diabetes care.     

Plasma alkaline phosphatase and pregnancy outcome

To investigate the change in adult T-cell leukemia incidence between 1983 and 1992 and to evaluate the sensitivity of the nationwide adult T-cell leukemia survey, we estimated adult T-cell leukemia incidence in the Kyushu district, southern Japan, where adult T-cell leukemia is endemic. The incidence of adult T-cell leukemia was calculated from the difference between Kyushu and the rest of Japan in mortality from malignant lymphoid neoplasms, i.e., Kyushu's excess rate was assumed to be due to adult T-cell leukemia. In Kyushu, average annual adult T-cell leukemia cases aged > or = 20 years were estimated for men as 252 during the period 1983-87 and 341 during 1988-92, and for women as 201 and 246 respectively. The age-adjusted mortality rate tended to be higher in the latter period [6.29 per 100000 (95% confidence interval 5.59-7.00) vs. 5.25 (4.60-5.90) in men, and 3.33 (2.85-3.80) vs. 3.18 (2.71-3.66) in women]. By contrast, the registered number of adult T-cell leukemia cases nationwide during 1988-93 was only 35% (203/587) of the estimated number, and the number of registered versus estimated cases decreased with age, especially when cases were > 60 years old. In conclusion, the estimated adult T-cell leukemia incidence for 1983-92 increased in the latter half of the period. The estimation suggests that 65% of adult T-cell leukemia cases might be missed by a nationwide survey, and older cases were more likely than younger ones to be missed.     

Prevalence of dementia in older Japanese-American men in Hawaii: The Honolulu-Asia Aging Study

OBJECTIVE: To determine prevalence of dementia and its subtypes in Japanese-American men and compare these findings with rates reported for populations in Japan and elsewhere. DESIGN AND SETTING: The Honolulu Heart Program is a prospective population-based study of cardiovascular disease established in 1965. Prevalence estimates were computed from cases identified at the 1991 to 1993 examination. Cognitive performance was assessed using standardized methods, instruments, and diagnostic criteria. PARTICIPANTS: Subjects were 3734 Japanese-American men (80% of surviving cohort) aged 71 through 93 years, living in the community or in institutions. MAIN OUTCOME MEASURES: Age-specific, age-standardized, and cohort prevalence estimates were computed for dementia (all cause) defined by 2 sets of diagnostic criteria and 4 levels of severity. Prevalence levels for Alzheimer disease and vascular dementia were also estimated. RESULTS: Dementia prevalence by Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised ranged from 2.1% in men aged 71 through 74 years to 33.4% in men aged 85 through 93 years. Age-standardized prevalence was 7.6%. Prevalence estimates for the cohort were 9.3% for dementia (all cause), 5.4% for Alzheimer disease (primary or contributing), and 4.2% for vascular dementia (primary or contributing). More than 1 possible cause was found in 26% of cases. The Alzheimer disease/vascular dementia ratio was 1.5 for cases attributed primarily to Alzheimer disease or vascular dementia. CONCLUSIONS: Prevalence of Alzheimer disease in older Japanese-American men in Hawaii appears to be higher than in Japan but similar to European-ancestry populations. Prevalence of vascular dementia appears to be slightly lower than in Japan, but higher than in European-ancestry populations. Further cross-national research with emphasis on standardized diagnostic methods is needed.     

Annual treatment rates and estimated incidence of eating disorders in Austria

BACKGROUND: At present, the prevalence and incidence of eating disorders in Austria is unknown; not even rough estimates of countrywide annual treatment rates are available. AIMS: To assess the number of patients in Austria with eating disorders currently under treatment and to compare this rate with the estimated prevalence and incidence of eating disorders, thus providing an estimate of unrecorded cases and the appropriateness of health care for these disorders. METHODS: The number of patients being treated in major out-patient and in-patient facilities was assessed by questionnaires. Prevalence and incidence rates in Austria were estimated by extrapolation of epidemiological data from comparable Western countries to Austrian figures from the most recent population census in 1991. RESULTS: Altogether 1075 patients were being treated in 1994 at 26 institutions, including all specialized centres, pediatric and psychiatric university hospitals. Surprisingly, the annual treatment rates for anorexia and bulimia nervosa were equal. There is a considerable discrepancy between these treatment figures and prevalence/incidence estimates (in absolute numbers): the estimated anorexia nervosa point prevalence is about 2500 girls aged 15-20 years, whilst a minimum of 4400 girls suffer from subclinical eating disorders, and there are about 6500 bulimia nervosa cases in young women aged 20-30 years. The incidence might be about 600 new onset cases per year for anorexia, and about 870 for bulimia nervosa. The size of the problem (lifetime prevalence) may comprise at least 36,000 women with bulimia nervosa. CONCLUSIONS: Eating disorders pose a major public health problem for women in Austria. It is unlikely that the vast majority of unrecorded cases was treated in private practice or in hospitals which failed to respond to our questionnaire. The discrepancy between annual treatment rates and prevalence/incidence estimates points to a lack of specialized eating disorder units in Austria.     

Orbital development after enucleation in early childhood

We studied the prevalence of dementing disorders in a rural municipality of Japan (Hanazono-mura), using a door-to-door two-phase design. In phase 1, the Hasegawa's Dementia Scale-Revised was applied as a screening test to all subjects aged 65 years and older (n = 201). Among subjects screened positive, 17 were diagnosed with dementia in phase 2. The prevalence (cases/100 aged 65 years and older) was 8.5 for all types of dementia, 3.5 for Alzheimer's disease, 3.0 for vascular dementia, and 2.0 for other dementia (including mixed dementia). The prevalence of dementia was slightly but consistently higher in men than women at all ages. The overall prevalence was higher in women for Alzheimer's disease and in men for vascular dementia.     

Incidence of inflammatory bowel diseases in the department of Puy-de-D?me in 1993 and 1994. EPIMICI. Epidémiologie des Maladies Inflammatoires Cryptogenetiques de l'Intestin group

The aim of this prospective epidemiological study was to investigate the incidence of Inflammatory Bowel Disease in the Puy-de-D?me county using the same methodology as EPIMAD's registry. METHODS: From 01/01/93 to 31/12/94, each gastroenterologist (n = 22) collected patients consulting for the first time with clinical symptoms compatible with inflammatory bowel disease. Data were reported on a questionnaire by an interviewer practitioner. The final diagnosis of Crohn's disease and ulcerative colitis was made in a blind manner by two expert gastroenterologists and recorded according to the Calkin's criteria as definite, probable, or possible diagnosis, or unclassifiable chronic colitis or acute colitis. RESULTS: 167 new cases were identified: 112 (67.1%) inflammatory bowel disease for the combined group of definite and probable cases with 79 Crohn's disease (70.5%), 29 ulcerative colitis (25.9%) of which 11 ulcerative proctitis (37.9%), 4 unclassifiable chronic colitis (3.6%) and 55 acute colitis (32.9%). The crude and age-adjusted incidence (per 10(5)/year) was respectively 6.6 and 5.7 for Crohn's disease and 2.4 and 1.9 for ulcerative colitis. The highest age-specific incidence rate for Crohn's disease was between 40-49 years (14.1) and for ulcerative colitis between 80-89 years (6.8). The female/male ratio was 0.8 for Crohn's disease and 1.1 for ulcerative colitis. The median age at the time of diagnosis was 42.6 years for Crohn's disease and 35.3 years for ulcerative colitis. CONCLUSIONS: These preliminary findings revealed a high incidence of Crohn's disease and low of ulcerative colitis in this county. However, these results must be managed carefully because these data were recorded only on two years and the inflammatory bowel disease classified possible and acute colitis require a follow-up.     

Declining HIV-2 prevalence and incidence among men in a community study from Guinea-Bissau

OBJECTIVE: To assess the present level of HIV-2 infection in an adult population in Bissau and to evaluate sex and age-specific changes in HIV-2 prevalence and incidence between 1987 and 1996. DESIGN AND METHODS: Sex and age-specific changes in HIV-2 prevalence were evaluated comparing a survey from 1987 in a sample of 100 houses with a survey performed in 1996 in an independent sample of 212 houses from the same study area. HIV-2 incidence rates were examined in an adult population (age > or = 15 years) from 100 randomly selected houses followed with four consecutive HIV serosurveys from 1987 to 1996. RESULTS: The HIV-2 prevalence in 1996 was 6.8% (men, 4.7%; women, 8.4%). Compared with the 1987 survey there was a significant decrease in prevalence among men [age-adjusted relative risk (RR), 0.50; 95% confidence interval (CI), 0.31-0.83], whereas it remained unchanged in women (RR, 1.00; 95% CI, 0.67-1.48). The male-to-female RR decreased from 0.99 (95% CI, 0.61-1.61) in 1987 to 0.51 (95% CI, 0.34-0.76) in 1996. The overall annual incidence rate was 0.54 per 100 person-years of observation (PYO), being higher in women (0.72 per 100 PYO) than in men (0.31 per 100 PYO). With the observation time divided into an early and a late period, there was a decrease in incidence with time among men (0.66 to 0.00 per 100 PYO), but no major change among women (0.59 to 0.85 per 100 PYO). The two trends differed significantly (P = 0.03). We observed a higher annual incidence rate amongst older women aged > 44 years (1.77 per 100 PYO) than among younger women (0.55 per 100 PYO; P = 0.05). CONCLUSION: There are no signs of an epidemic spread of HIV-2 in Bissau even though the HIV-1 prevalence is increasing rapidly. A significant reduction in the male HIV-2 prevalence and incidence rates has resulted in a major shift in the pattern of spread of HIV-2, from being equally distributed to being predominantly a female infection. Currently, older women in particular seem to have a high risk of getting infected.     

Prevalence of alcohol dependence and abuse in general practice

The aim of this study is to deliver representative epidemiological data about the prevalence of alcohol abuse and dependence in general practices in an urban area. In 12 general practices at Luebeck, a Northern German city with 220,000 inhabitants, a total of 929 patients (aged between 14 and 75 years) were screened using the CAGE and the Short Michigan Alcoholism Screening Test. If one of these screening questionnaires or the General Practitioners' assessment of the patient indicated an alcohol problem, the patient underwent a standardized diagnostic interview using the alcohol section of the Schedules for Clinical Assessment in Neuropsychiatry. The prevalence rates according to ICD-10 or DSM-III-R were 3.5% for alcohol abuse and 7.2% for alcohol dependence, the sex ratio was 1:2.8 (female:male). These results are compared with previous findings, and general epidemiological implications of this study are discussed.     

Stability of plasma-polymerized allylamine films with sterilization by autoclaving

BACKGROUND: Survey data on the prevalence of use of oral snuff (toombak) and cigarette consumption according to various demographic factors are needed in the Sudan. METHODS: A house to house cross-sectional survey of a random population sample of 4,535 households was performed. Of the 23,367 household members identified, 21,648 (92.6%) eligible individuals were questioned about tobacco use. RESULTS: Among children and adolescents (4-17 years) prevalence of tobacco use was quite low (2%, range 1-2%), but there was an abrupt increase up to 25% in late adolescence. Among the adult population aged 18 years and older the prevalences of toombak use (34%) and cigarette smoking (12%) among males were significantly higher than among females (2.5 and 0.9%, respectively). The prevalence of toombak use among the male population aged 18 years and older was significantly higher in the rural than in the urban areas (35% vs 24%), while cigarette smoking had a higher prevalence in urban areas (18% vs 12%). The highest rates of toombak use were found in rural areas among the male population ages 30 years and older (mean 46.6%, range 45-47%). CONCLUSIONS: In view of the high prevalence of tobacco use, especially of toombak, among the population surveyed, there is an urgent need to educate the public on the health consequences of these habits.     

Mode of presentation and multisystem involvement in Beh?et's disease: the influence of sex and age of disease onset

OBJECTIVE: To evaluate the correlation between the age at onset of Behcet's disease (BD) and sex distribution, mode of disease appearance, and number of organs involved during the disease. METHODS: BD was defined according to the International Study Group criteria. Data from medical files and from patient interviews were collected. Results were analyzed for children and adults, according to age at disease onset. A systemic involvement index was calculated as the sum of visceral organ systems involved. RESULTS: Fifty-nine patients with BD were studied, 26 male and 33 female. The mean age at disease onset was 8.4 +/- 4.5 years in children and 29.8 +/- 7.9 years in adults. The age of onset was significantly lower in male versus female patients. BD presented in children almost entirely as recurrent aphthous stomatitis, while in adults, less than one-third of patients presented first with oral ulcers. The mean age at disease onset of patients who presented first with oral ulcers was significantly lower than the age of patients presenting first with non-oral aphthosis. The mean systemic involvement index was higher in adult onset than in juvenile onset disease. A significant linear correlation was found between age of disease onset and total number of visceral organ systems involved. CONCLUSION: BD was observed to occur earlier in males than in females. The first manifestation of BD in children is almost exclusively in the form of oral ulcers, while older patients have a large proportion of non-oral aphthosis as their first disease manifestation. Disease onset at an older age is positively correlated with increased disease spectrum.     

Specificity of the Speed''s test: arthroscopic technique for evaluating the biceps tendon at the level of the bicipital groove

A historical cohort study was conducted in Misasa town, Tottori prefecture, Japan, where radon spas have been operating for a long time. Misasa town was divided into an elevated radon level area and a control area, with mean indoor radon levels of about 60 and 20 Bq/m3, respectively. In total, 3,083 subjects in the elevated radon level area and 1,248 in the control area, all aged 40 or older on January 1, 1976, were followed up until December 31, 1993, for a mean period of 14 years. The mortality rates from all causes exhibited no difference between the elevated radon level area and the control area for both sexes. No difference was observed in the incidence of all-site cancers (age, period-adjusted rate ratios by Poisson regression, RR = 1.06, 95% confidence interval (CI) 0.79-1.42 for males, RR = 0.90, 95% CI 0.65-1.24 for females), while stomach cancer incidence seemed to decrease for both sexes (RR = 0.70, 95% CI 0.44-1.11 for male, RR = 0.58, 95% CI 0.34-1.00 for female) and lung cancer incidence for males only seemed to increase (RR = 1.65, 95% CI 0.83-3.30 for male, RR = 1.07, 95% CI 0.28-4.14 for female) in the elevated radon level area. Caution is needed in the interpretation of these findings, however, since the individual exposure level was not measured and major confounding factors, such as smoking and diet, could not be controlled in this study.     

Incidence and prevalence of symptomatic celiac disease among adults in Denmark

The purpose was: 1) to determine annual incidence rates of adult coeliac disease, 2) to calculate the risk of having developed coeliac disease in adult life, and 3) to calculate the life time prevalence by five-year birth cohorts. All patients fulfilling defined criteria for adult coeliac disease living in the county of Copenhagen and diagnosed during the years 1976-1991 were included. The reference population consisted of 503,283 subjects. The overall incidence had been stable during the period, and was 1.27/10(5). The figures for females and males were 1.55/10(5) and 0.96/10(5), respectively (p = 0.04). The median (range) age at the time of diagnosis was 40.1 (16-81). Age specific incidence rates varied considerably, with the peak rate located in the middle-aged population. The incidence rates were influenced by age at diagnosis (p = 0.01) and sex (p = 0.04), but not by the year when diagnosed. For a subject aged 89 years, the risk was 0.88/1000. The overall prevalence was 45.9/10(5). In conclusion, this incidence/prevalence is one of the lowest reported, and is definitely lower than prevalences reported from our neighbouring Scandinavian countries. Nothing points to higher incidence rates being present in Danish adults to compensate for the previously demonstrated very low rates in Danish children.     

Burden of disease in the aged, Mexico, 1994

OBJECTIVE: To estimate the disability adjusted life years lost (DALYs) in population over 60 years of age in Mexico during 1994. MATERIAL AND METHODS: Years of life lost due to premature mortality (YLL) and years lived with disability (YLD) were estimated for 108 diseases, both sexes, and 32 states of the Mexican Republic divided in rural and urban areas in the population over 60 years of age, using the methodology originally proposed by Murray and López adapted to specific local characteristics. The inputs used were: mortality statistics for 1994 (after corrections of under-registration and misclassification), statistics on incidence and prevalence from local epidemiological studies, national health surveys and estimates by the authors. RESULTS: During 1994 the Mexican population over 60 years of age lost 1.8 million DALYs, 59% of which were YLL while 41% were YLD. Most of the burden of disease is due to noncommunicable diseases. The principal health needs of the elderly in Mexico can be divided in two groups: a) those that traditionally are frequent in this age group, such as ischaemic heart disease, diabetes, stroke and b) disabling diseases such as dementia, falls and arthritis as the most important. CONCLUSIONS: The use of composite indicators such as DALYs to assess health needs in older adult can help decision-makers and planners to incorporate disabling and lethal diseases within the list of priority needs, thereby achieving greater equity in the assignment of resources to different health care, prevention and rehabilitation programs.     

Adenomatoid odontogenic tumours in Ibadan, Nigeria

Only a few reports of adenomatoid odontogenic tumour (AOT) in Africans have been published. Clinical, histological and radiographic features as well as treatment results of thirteen new cases of AOT seen at the University College Hospital, Ibadan were reviewed. This lesion constituted 12.1% of odontogenic tumours. This study shows a male: female ratio of 1.2:1. This contrasts with the reported male: female ratio of 1:3 in the United States, Britain, Sri Lanka and Japan. The higher male incidence may be peculiar to Nigeria. Although the peak incidence was in the second decade of life, four patients were over 20 years of age. The mean age was 23.2 years for all patients. None of the patients presented with recurrence on follow up.     

Milia restricted to the eyelids

The present study was performed to estimate the prevalence of Rett syndrome in Fukui prefecture by sending questionnaires to special classes (classes for handicapped children in schools for normal children) and schools for mentally/physically handicapped children, and observing children suspected of having this syndrome on the basis of answers to the questionnaire. The subjects were girls aged 6-14 years who were attending 11 special classes and 7 schools for handicapped children. The prevalence of Rett syndrome was estimated to be 0.22 per 10,000 girls aged 6-14 years in Fukui prefecture, as of April 1, 1993. The prevalence noted in this study was lower than those found in previous studies in Japan and Western countries.     

Carcinosarcoma of the uterine body of mesonephric origin

A full year's epidemiological study was conducted in Japan on prenatal infection with Setaria marshalli in cattle. A total of 65 bovine fetuses of abattoir origin, both male and female of 2-9 months of age, were examined postmortem. Results showed that S. marshalli adult worms were detected in the peritoneal cavity of six bovine fetuses of 7-9 months of age during the months of October-December, but not in fetuses of any age during the months of January-September. Infection was not detected in any fetuses under the age of 7 months at any given month of the year. This is the first observation to demonstrate prenatal S. marshalli infection in fetuses. Since S. marshalli has not been detected in cattle older than 2 years, it is speculated that prenatal infection is the common type, while postnatal infection is rather uncommon. Considering fetal age and the seasonal factor, a fetus of age 4-5 months would most frequently develop prenatal infection in the June-August period, when mosquitoes are active as vectors. It is concluded, therefore, that S. marshalli prenatal infection develops during the middle stage of fetal life in summer.     

Anomalies of umbilical vein in the fetus. A case report and review of the literature

Measuring the incidence of the human immunodeficiency virus (HIV) is of vital importance but can be difficult and costly. We compared HIV-1 incidence measured directly from prospective cohort studies with rates derived from a method using the prevalence of HIV-1 antibody-negative, p24-antigen-positive individuals. Male and female commercial sex workers (CSWs) were enrolled and followed in separate cohort studies in northern Thailand between 1989 and 1994, and HIV incidence was measured by prospective follow-up of individuals seronegative at baseline. In 1991-1992 cross-sectional serosurveys were done among male and female CSWs in the same region; all HIV-1 antibody-negative subjects in these surveys were tested for p24 antigenemia. HIV incidence was estimated using the prevalence of p24 antigen and a model based on the mean duration of p24 antigenemia before HIV antibody detection. The cohort studies showed high initial incidence rates-23.8/100 person-years (PY) among female CSWs and 11.9/100 PY among male CSWs-but poor compliance with prospective follow-up. Subjects lost to follow-up appeared to be at greater risk of HIV seroconversion than those retained. The p24 antigen method estimate among female CSWs, 25.4%/year, was quite similar to the initial incidence rate found in the cohort. The estimate by the p24 antigen method was higher, 19.9%/year, among male CSWs than that measured prospectively. In populations with high rates of HIV transmission and in whom long-term follow-up is incomplete, estimates of incidence using p24 antigen prevalence among antibody-negative subjects can give useful and economical estimates of HIV incidence and allow for estimates of whether the incidence rates are similar in subjects successfully followed and those lost to follow-up.     

Epidemiological observations on sarcoids in a population of donkeys (Equus asinus)

An epidemiological study of equine sarcoid in a population of 4126 donkeys showed that the peak incidence of the disease was 15.2 cases per 100 animal-years and occurred in animals in their fourth year of life. The crude incidence of the disease was 0.6 cases per 100 animal-years. The disease occurred most frequently in younger, male animals during their first five years in the population. The lesions were observed most commonly in the paragenital region. Pre-entry quarantine procedures did not appear to play a significant role in the spread of the disease but there was an indication that close in-contact animals were more likely to have sarcoids than animals in the general population. This suggested that a transmissible agent might have been involved in the aetiopathogenesis or that the animals had encountered some event that had predisposed them to the disease.     

Specific features of nosocomial infections in the elderly at a general hospital center. 5 surveys of annual prevalence

Specific features of nosocomial infections in patients aged 70 years or older admitted to a short-term care medical department in a 400-bed general hospital were studied to assist in designing nosocomial infection control programs for this population. Data from five annual prevalence surveys were evaluated retrospectively. The 517 patients aged 70 years or older were compared to the 1093 patients younger than 70 years. The older patients were more likely to have risk factors for nosocomial infections including severe disease (36.2% vs 19.1%; P < 10(-6)), referral from another department (24.6% vs 17.5%; P < 0.01), a long hospital stay duration (8.5 days vs 3.5 days), mechanical ventilation (4.3% vs 1.6%; P < 0.01), an indwelling urinary catheter (12.0% vs 4.0%; P < 10(-7)), and a long median duration of urinary catheterization (6 days vs 2 days). The prevalence of nosocomial infections was increased nearly two-fold in the older patients (10.3% vs 5.6%; P < 0.01), although the difference was statistically significant only for urinary tract infections (5.4% vs 1.4%; P < 10(-5)), particularly in patients without urinary catheters. After exclusion of all patients with urinary tract infections, the prevalence of nosocomial infections was similar in the older and younger patients (4.3% vs 3.7%) despite a persistently higher frequency of risk factors for nosocomial infection in the older group. These results indicate that urinary tract infection should be the main target of programs aimed at minimizing nosocomial infection in elderly patients admitted to short-term care facilities. Faultless technique is essential during urinary catheter insertion. High-quality nursing care contributes substantially to the prevention of urinary tract infection in noncatheterized patients with urinary incontinence or neurologic disorders.