Descriptive Epidemiological Data Research Articles

Descriptive Epidemiology of Dozing and Driving in a College Student Population

Driving while fatigued is a serious risk-taking behavior among college students. Accident data were reviewed and a behavioral risk factor survey undertaken at a large private university. The findings indicated that 86 motor vehicle fatalities occurred among students at the university in the last 15 years. The authors estimated that falling asleep at the wheel may have caused 62 of these accidents and that more than 3,000 students experience a driving–dozing incident annually, resulting in a yearly average of 200 injury accidents and 4 fatalities. Descriptive epidemiologic data are presented and implications for health promotion efforts are discussed.

Epidemiological surveillance of rabies in Lithuania from 1986 to 1996.

Rabies has been endemic in Lithuania for centuries. The objective of this study was to evaluate rabies incidence and seasonal trends in domestic and wild animals in Lithuania from 1986 to 1996. Annual rabies reports and data on cattle numbers were collected. Descriptive epidemiology and time series data analyses were performed to detect seasonal trends. A total of 1,475 specimens were submitted for rabies testing. Of these, 1,248 (84.6%) were confirmed as rabies cases by immunofluorescence antibody testing. Domestic animals accounted for 73.8% (921/1,248) of all rabies cases, with cattle accounting for 61.1% (563/921) of domestic animal cases. Wildlife cases were reported principally in red foxes (56%; 183/327) and raccoon dogs (31.2%; 102/327). Time series analysis indicated a strong association between the occurrence of rabies in cattle and the season of the year (P = 0.0032), with the highest incidence of rabies occurring in autumn. The incidence declined from 3.4 to 4.8 cases per 100,000 cattle in the mid-1980s to < 1.5 cases per 100,000 cattle in 1994, but increased to 4.2 cases per 100,000 cattle in 1996. However, as the cattle population dramatically decreased (by 54%) over the eleven-year period of the study, the reduction in the total number of rabies cases in cattle was not reflected in the annual incidence rate of cattle rabies.

Epidemiology of cancer of the lip in The Netherlands.

Descriptive epidemiological data of new cases of squamous cell carcinoma of the vermilion border of the lip in the Netherlands from 1989-94 inclusive are presented. Lip cancer represented 0.47 and 0.09% of all new malignancies in males and females, respectively. The lower lip was the most frequently affected site. The majority of the lip cancers were diagnosed in tumour stage I. The median age at diagnosis in males was 68 years, 5 years less than in females. The overall male-to-female ratio was 5.7. Age-adjusted incidence rates in males and females were 2.2 and 0.3 per 100,000 (ESR), respectively. The cumulative lifetime risk for developing lip cancer was 0.15 for males and 0.03 for females. Mortality/incidence ratios in males and females were 0.05 and 0.07, respectively. Differences in lip cancer incidence were observed between an urban and a rural area. There was a positive association between the occurrence of lip cancer and rural residence; rate ratios were 3.3 among males and 3.5 among females.

Growing evidence that several human cancers may originate in utero

Hormone-related cancers may originate in utero. Accumulating evidence is given by animal studies, descriptive epidemiologic data and analytic etiologic studies. Indicators of high levels of endogenous pregnancy hormones, like high birth weight and jaundice in the offspring, are associated with increased risk for breast, prostate, and non-seminoma testicular cancer. Indicators of low levels, like pre-eclampsia, are associated with decreased risk. These results support the hypothesis that the pre- and perinatal periods constitute a ‘time window’ that is of major importance for future cancer risk.

Diet, androgens, oxidative stress and prostate cancer susceptibility.

Prostate cancer is the most common human malignancy and the second leading cause of cancer deaths among men in Western nations. Descriptive epidemiologic data suggest that androgens and/or environmental exposures, such as diet (in particular, dietary fat), play an important role in prostatic carcinogenesis. One plausible link between diet and prostate cancer is oxidative stress. This process refers to the generation of reactive oxygen species, which can then trigger a host of pro-carcinogenic processes. Recent studies also indicate that androgens increase oxidative stress within human prostate cancer cell lines. Recent data from our institution indicate that oxidative stress is higher within the benign epithelium of prostate cancer patients than men without the disease. This confirms our hypothesis and suggests that antioxidants such as lycopene, vitamin E, and selenium may play an important role in preventing disease progression. Large-scale clinical trials with some of these agents are currently in the design phase.

Incidence, mortality and prevalence of stomach cancer in Italian regions.

The basic descriptive epidemiologic data on stomach cancer occurrence in Italian regions are presented and discussed. Incidence and prevalence were estimated from official mortality and survival data provided by four population-based Italian cancer registries. Age-adjusted mortality, incidence, and prevalence rates are presented by region for the year 1990. Time trends of incidence and their projection for the year 2000 are also presented by region and three broad age classes. Although the occurrence of stomach cancer has been decreasing in Italy and most western countries over the last decades a substantial slowing down of this decrease was evidenced in Italy, especially for women under 65 and for the regions of southern Italy. A marked tendency towards a reduction of geographic heterogeneity in stomach cancer occurrence was also shown. Such a phenomenon is consistent with the observed changes of dietary habbits in Italian regions. The regions of Umbria and The Marches seem to emerge as new areas at relatively high risk of stomach cancer incidence and mortality. About 45,000 prevalent cases were estimated in Italy by 1990, half of which have been diagnosed before 1984.

Ethnic, socioeconomic, and sex differences in physical activity among adolescents

Regular physical activity is recommended for health maintenance in adolescence, but basic descriptive epidemiological data are lacking for this age group. The present study examined socioeconomic status (SES), ethnic, and sex differences in physical activity in a multiethnic sample of 1871 high school students in San Diego, California. Surveys were completed in required classes by a diverse sample of students from a low-income school district and by Anglo students from a nearby more affluent district. Boys reported more vigorous exercise outside of school and during school physical education, as well as more participation in sports teams, but girls reported taking more activity-related lessons and classes. High-SES students had more frequent physical education classes, spent more time in vigorous exercise in those classes, and participated in more activity lessons outside of school. There were few ethnic differences on summary physical activity or physical education variables. There were no SES differences, but there were ethnic differences on 5 of 22 specific activities. Demographic differences in 25 psychological, social, and environmental variables that may influence physical activity were also examined. Differences between boys and girls were found on several variables, which may explain some of the boys' higher activity levels. Ethnic and/or SES differences were found in 10 of 25 potential correlates of physical activity. These data may be used to identify specific activities that may be preferred by subgroups of adolescents and specific mediating variables that can be targeted in physical activity promotion programs for adolescents.

The mortality rates for multiple sclerosis in Italy (1969-1987).

The mortality for multiple sclerosis in Italy was analyzed for the period 1969-1987. The age-adjusted (to Italian 1981 population) death rates decreased slightly during these years for both sexes. The average national female/male ratio of the age-adjusted rates is 1.33 and shows a north-south gradient, with values < 1 in the South-Islands area where multiple sclerosis cases are probably heavily underreported on the death certificates. A positive, significant correlation between the age-adjusted death rates and latitude of the 20 Italian regions exists for the period 1969-1975; in recent years (1981-1987), these parameters show a weaker, but not statistically significant positive correlation. Moreover, the 95% confidence intervals of the death rates in the 20 regions overlapped extensively in both periods studied (1969-1975 and 1981-1987). Death rates for multiple sclerosis are a weak index of the frequency of the disease and their utility is restricted to national surveys. The descriptive epidemiological data (incidence, prevalence, mortality) available at present in Italy do not seem to support a link between multiple sclerosis and latitude.

Chronic pain in a geographically defined general population: studies of differences in age, gender, social class, and pain localization.

To establish basic epidemiological data on chronic pain (duration > 3 months) in a defined population. Relationships between age, gender, and social class were tested. A survey of pain symptoms, including location, intensity, duration, and functional capacity, was conducted by means of a mail questionnaire. General populations in two Swedish primary health care districts. Medical care was provided in a state health system. A random sample (from the population register) of 15% of the population aged 25-74 (n = 1,806). The response rate was 90%. Descriptive epidemiologic data in relation to objectives of the study. Without sex differences, 55% (95% confidence interval, 53-58%) of the population had perceived persistent pain for 3 months and 49% for 6 months. Among individuals with chronic pain, 90% localized their pain to the musculoskeletal system to a variable extent. Women experienced more multiple localizations of pain and had pain in the neck, shoulder, arm, and thigh to a greater extent than men. Prevalence of pain increased by age up to 50-59 years for both genders and then slowly decreased. The neck-shoulder area was the most common site of pain (30.2%), followed by the lower back (23.2%). Even in the youngest age groups more than one of four reported chronic pain. Blue-collar workers and employers (including farmers) reported chronic pain to a greater extent than other groups. In 13% of the population, manifest pain problems were associated with reduced functional capacity. Chronic pain symptoms are common but unevenly distributed in a general population. The results may influence planning and consultation in primary health care as well as warranting selective prevention activities.

Diabetes Prevalence, Incidence, and Complications Among Alaska Natives, 1987

To provide descriptive epidemiological data on diabetes mellitus among Alaska Natives, including incidence, updated prevalence, and incidence rates of ESRD, LEA, MI, and stroke in the diabetic population. In IHS and tribal contract hospitals and clinics throughout Alaska, Alaskan Indians, Eskimos, and Aleuts living in Alaska with documented diabetes mellitus were studied from 1986 to 1987. The number of diabetic patients increased from 610 to 708, and the prevalence changed from 15.7 to 17.4/1000 (not a statistically significant increase). Incidence rates per 10,000 diabetic person-yr for complications were 38 for ESRD, 69 for LEA, 92 for MI, and 92 for stroke. The prevalence of diabetes mellitus increased during the period of observation, but not to a statistically significant degree. Incidence rates for diabetes are lower than for the U.S. general population, but complications rates are as high as those in other diabetic populations.

Some new aspects of CJD epidemiology in Slovakia

Descriptive epidemiological and genealogical data obtained by prospective and retrospective studies on CJD in Slovakia and in patients emigrating from CJD clusters were analysed. Observations contradictory to an exclusively genetic etiology of temporo-spatial accumulation of CJD are presented. Data indicating a genetically increased susceptibility to the disease and its coincidence with environmental risk in clustering patients are discussed.

Prevalence of primary fibromyalgia in the Finnish population.

To obtain descriptive epidemiological data on fibromyalgia and its components in a representative sample of the Finnish population. Cross sectional study of 8000 Finns aged 30 or more invited for screening and a main examination for musculoskeletal disorders and other major disorders. A mobile clinic. 7217 subjects who attended the screening phase; 3434 subjects positive on screening who attended the main examination for musculoskeletal disorders. Musculoskeletal, mental, and other symptoms detected by interview and questionnaire; results of standardised clinical examination of the musculoskeletal system; operational definition of fibromyalgia; mortality at 10 years. The prevalence of fibromyalgia was low (54 cases; 0.75%) and related to age (peak prevalence at 55-64 years), female sex (twice as prevalent in women), occupation (no cases among 1596 white collar professionals), level of education (strong inverse gradient), and high levels of physical stress at work. No significant associations were found with body mass index, smoking, or mental stress at work. The prevalence of fibromyalgia was sensitive to even minor modifications of the definition. Fibromyalgia was strongly coincident with many other disorders, especially musculoskeletal conditions. Fibromyalgia did not predict mortality. Descriptive epidemiological data offer little support for the concept of fibromyalgia.

Factors influencing the assessment of treatment needs

Epidemiologic surveys have provided data for health planning by estimating prevalence and incidence of diseases in populations. New ways of presenting epidemiologic data on periodontal diseases have changed our understanding of their extent and severity, and conversion of prevalence data into treatment need estimates has proved difficult. Furthermore, new concepts of the pathogenesis of periodontal diseases have questioned the validity of epidemiologic methods currently used. Treatment need assessments vary considerably between studies even when prevalence data from the same populations are similar. This may be due to lack of described goals for periodontal health. Various aspects of the concept of need for treatment are discussed. It is suggested that periodontal treatment need on a population level is defined as the intervention needed in order to change the existing periodontal condition to the described goal. Thus, treatment need assessments will have to include descriptive epidemiologic data as well as defined periodontal health goals. It is recommended that goals are described in terms compatible with the indicators used in the epidemiologic description of the disease status.

Use of Social Science Research to Improve Epidemiologic Studies of and Interventions for Diarrhea and Dysentery

The significance of dysentery has not been recognized in community-based programs for the management of diarrhea. Culturally sensitive methods of classification and algorithms for treatment of these diseases must be developed. Considered in this article is the manner in which ethnographic studies of diarrhea can contribute to descriptive epidemiologic data on diarrhea and dysentery and to procedures of health education and evaluation of interventions for the diseases. Indigenous terms for bloody diarrhea exist in many cultures. Local use of such terms must be carefully examined before they are incorporated in health education efforts and epidemiologic surveillance programs.

Sudden infant death syndrome and birth weight

We studied 2962 cases of sudden infant death syndrome (SIDS), derived from linked birth and death records, to specify further the descriptive epidemiologic data on recognized SIDS risk factors and to examine interrelationships among multiple risk factors and SIDS while controlling for the influence of birth weight (using logistic regression). The results generally confirmed those of other studies, with the exception of a higher incidence of SIDS among Chinese and Japanese babies and a lower incidence among Hispanic babies, all in comparison with white, non-Spanish (Anglo) infants. Median age at death was found to vary by birth weight, with very low birth weight babies being about 6 weeks older (postnatal age) than normal birth weight babies at time of death. The association of the risk factors with SIDS remained when birth weight data were statistically controlled; the association of these risk factors with SIDS cannot be explained by their relationship to birth weight. An interaction was found between race and maternal age and between multiparity and type of hospital of birth. There was no interaction between birth weight and the other risk factors.

Guinea worm disease in Northern Uganda: a major public health problem controllable through an effective water programme.

A modified cluster survey was conducted in northwestern Uganda in 1984 to provide descriptive epidemiological data on dracunculiasis in a water programme target area. A total of 2014 people participated from 58 randomly selected clusters. Interviewers elicited information on age and sex of household members, number, date of emergence and location of Guinea worms, and type of and distance from water source in an endemic area. The survey yielded an incidence rate of 193 cases/1000 people per year, and a prevalence rate of 43 active cases/1000. Respondents who reported using ponds, reservoirs, valley tanks or rivers as their primary water source had the highest attack rates; those using boreholes, the lowest. Adolescents and adults differed little in risk, but the disease was less common among young children. Guinea worm disease displayed a bimodal seasonal pattern. We concluded that the survey method used for determining dracunculiasis incidence was appropriate in this setting. The incidence of this disease may be significantly reduced in Uganda through the country's commitment to the International Drinking Water Supply and Sanitation Decade.

Epidemiology of ambiguous genitalia in South America.

We present descriptive epidemiologic data on ambiguous genitalia (AG), obtained in the period 1967-1982 by the Latin American Collaborative Study of Congenital Malformations (ECLAMC) through 70 participating hospitals located in 34 cities of 9 South American countries. The observed prevalence rate for isolated AG was about 1/20,000 births, with at least 1/4 and probably as much as 1/2 due to congenital adrenal hyperplasia. When AG cases associated with other congenital anomalies were also considered, the overall frequency of AG was 1/6,900 total births (1/10,000 for live and 1/350 for stillbirths). The prevalence rates were homogeneously distributed among the different countries, and there was a stable secular trend. AG was more frequent in nontropical than in tropical areas of South America, and there was a significant seasonal variation with its acrophase in August (winter). A case-control analysis of 14 risk factors showed an association of AG with a prenatal history of acute maternal illnesses. These data do not support an etiological relationship between AG and hypospadias.

A retrospective study of Creutzfeldt-Jakob disease in England and Wales 1970-1979. II: Epidemiology

A comprehensive search yielded 121 confirmed cases of Creutzfeldt-Jakob disease who died in England and Wales in the decade 1970-1979, 31 probable cases and 10 possible cases. Descriptive epidemiological data are presented. The average annual incidence was 0.3 cases/million. An unexpected female excess was found. There was no evidence of space-time clustering of cases and no associations with occupation or past medical treatment were apparent. There was statistically significant variation in incidence rates in different parts of the country but no relationship was discovered between incidence and population density.

A retrospective study of Creutzfeldt-Jakob disease in England and Wales 1970-1979. II: Epidemiology.

A comprehensive search yielded 121 confirmed cases of Creutzfeldt-Jakob disease who died in England and Wales in the decade 1970-1979, 31 probable cases and 10 possible cases. Descriptive epidemiological data are presented. The average annual incidence was 0.3 cases/million. An unexpected female excess was found. There was no evidence of space-time clustering of cases and no associations with occupation or past medical treatment were apparent. There was statistically significant variation in incidence rates in different parts of the country but no relationship was discovered between incidence and population density.

Descriptive Epidemiology of Creutzfeldt-Jakob Disease in Chile

Descriptive epidemiological data are presented from a survey of 35 cases of Creutzfeldt-Jakob disease (CJD) that occurred in Chile in the period 1955 to 1977. The average mortality in Chile (0.31 deaths per 1 million) and in urban Santiago (0.73 deaths per 1 million) is compared with data reported from other countries. An increasing incidence in recent years is probably related to a greater awareness of the disease. The familial occurrence of CJD in nine patients from five affected families is described, and its analysis suggests a genetically determined susceptibility with incubation periods of more than 30 years. Horizontal transmission of the disease may have occurred in one patient in whom the disease developed 13 years after the patient married into a family with seven other affected members.