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PubMed1992

AIDS incidence and income.

Since 1987, the annual increases of AIDS incidence among homosexual and bisexual men have slowed but the increases among other risk groups have continued unabated. Although indirect evidence suggests the incidence change is related to medical care for HIV disease delaying the onset of AIDS, other explanations are also possible. To examine the incidence change from a different perspective, we classified the residents of Philadelphia (PA, U.S.A.) with AIDS by the per capita income of their census tracts of residence. AIDS incidence increased steadily in the lowest income tercile, showed continuing but smaller increases after 1987 in the middle tercile, and was level after 1987 in the highest income tercile. The relationship between income and changes of incidence persisted after stratification on race or mode of infection with HIV. Income was associated with private medical insurance at the time of diagnosis of AIDS (59% privately insured in the highest income tercile, 24% in the lowest) and with median survival after a diagnosis of AIDS (467 days in the highest tercile of income, 359 days in the lowest). These observations are consistent with a medical treatment benefit that reaches the highest tercile of income and does not reach the lowest one.

Acquired Immunodeficiency Syndrome↗

PubMed1977

The increasing incidence of breast cancer in Alberta 1953-1973.

The incidence of female breast cancer in Alberta increased steadily by one case per 100,000 per year from 1953 to 1973 to a current rate of 68.6 per year when adjusted to the 1950 U.S. population. Incidence rates of breast cancer in Alberta and Saskatchewan were identical after population adjustment. The incidence increased in women over 40, implicating an increase in the postmenopausal type of breast cancer. Birth cohort analysis showed increased age-specific incidence rates in middle-aged women occurring in successive cohorts from 1903 to 1918, a result similar to that found in Saskatchewan, Connecticut, and Finland. The menopausal hook is disappearing in Alberta data, apparently due to cohort-specific increases in incidence. Possible etiological factors involved in these incidence changes are discussed; a detailed analysis of specific etiological factors is currently underway on over 3,000 patients with malignant or benign breast disease who were examined at the Dr. W. W. Cross Cancer Institute in Edmonton from 1971 to 1974.

Adult↗

PubMed1992

Pelvic inflammatory disease: trends in hospitalizations and office visits, 1979 through 1988.

OBJECTIVES: We attempted to assess trends in pelvic inflammatory disease occurrence and to describe current antibiotic treatment and use of surgical procedures for pelvic inflammatory disease in the United States. STUDY DESIGN: Analyses of hospitalizations according to the National Center for Health Statistics, National Hospital Discharge Survey for 1979 to 1988, and of office visits to private physicians from the National Disease and Therapeutic Index for 1979 to 1989 were done. RESULTS: From 1979 to 1988, a mean of 181,700 women aged 15 to 44 years were hospitalized each year for acute pelvic inflammatory disease (3.03/1000 women) and 94,400 for chronic pelvic inflammatory disease (0.90/1000), and nearly 400,000 first visits for pelvic inflammatory disease were made each year to private physicians' offices (7.2/1000 women). Mean visit and hospitalization rates for acute pelvic inflammatory disease were highest for women aged 20 to 24 years and for other-than-white women. By 1987 to 1988, however, pelvic inflammatory disease hospitalization rates were highest for teenagers. Surgery was performed during 42% of hospitalizations for acute pelvic inflammatory disease and 90% of hospitalizations for chronic pelvic inflammatory disease. Over this time period, hospitalization rates for acute pelvic inflammatory disease decreased by 36% while office visit rates remained unchanged. CONCLUSION: This decrease in hospitalizations for pelvic inflammatory disease may indicate a true decrease in its incidence, changes in physician hospitalization practices, or a shift in the spectrum of severity of pelvic inflammatory disease.

Adolescent↗

PubMed1990

Overcoming deficiencies of the rule-based medical expert system.

One of the current deficiencies of the rule-based expert system is its static nature. As these systems are applied to medicine, this shortcoming becomes accentuated by: the rapid speed at which new knowledge is generated, the regional differences associated with the expression of many diseases, and the rate at which patient demographics and disease incidence change over time. This research presents a solution to the static nature of the rule-based expert system by proposing a hybrid system. This system consists of an expert system and a statistical analysis system linked to a patient database. The additional feature of a rule base manager which initiates automatic database analysis to refresh the statistical correlation of each rule ensures a dynamic, current, statistically accurate rule base. The philosophical differences between data and knowledge are also addressed as they apply to this type of hybrid system. The system is then used to generate four rule bases from different knowledge sources. These rule bases are then compared.

Artificial Intelligence↗

PubMed1992

Changing epidemiology of hepatitis B in Italy: public health implications.

In Italy, a dramatic decline of hepatitis B infection occurred in recent years as a result of nonmedical and medical factors. The national type-specific surveillance system shows that the age of maximum incidence changed from early childhood, when the risk of becoming a chronic carrier after infection is very high, to late adolescence. Data of several seroepidemiologic studies are consistent with this picture, but could not be compared with previous data on similar age groups. In 1981, a seroepidemiologic study on a national sample of 5,005 recruits showed a high prevalence of serologic markers of hepatitis B infection among young adults in Italy. In 1990, the authors replicated that original study on a national sample of 4,993 recruits. The adjusted prevalence of hepatitis B core antibodies among Italian male recruits dropped from 16.8% to 5.8% in 9 years. The authors anticipate a substantial reduction in the rate of production of chronic carriers and the rates of liver cirrhosis and primary liver carcinoma in Italy in the next decades. Vaccination campaigns, especially if combined with nonimmunologic preventive measures, will further reduce the rate of hepatitis B infection in Italy.

Adolescent↗

PubMed1989

Availability of psychotropic drugs and suicidal self-poisoning mortality in Belgium from 1971-1984.

Trends in completed suicide by solid or liquid substances in Belgium were investigated for the period 1971-1984 in relation with data about sales of psychotropic drugs. Mortality rose sharply between 1973 and 1980 (from 21.1 per million population of 15 years and older to 52.2 in males and from 26.7 to 61.7 in females) and decreased slightly thereafter. No apparent coincidence with the availability of psychotropic drugs was found, and the increasing risk of suicidal persons dying at home suggested an increase in the severity of the attempts until 1980. However, incidence changes could also have affected these trends. The evolution in accidental and in suicidal hospital rates suggested that emergency care had improved. Although barbiturate sales decreased continuously (from 46.7 packages per year per 100 population in 1974 to 28.5 in 1984), these drugs still account for a high proportion of fatal self-poisonings (23%) in Belgium. Possible shortcomings that could affect the validity of our findings are discussed.

Adolescent↗

PubMed1979

An analysis of 500 cases of equine cryptorchidism.

The authors analyse data collected over 23 years from 500 cryptorchid horses. They show that left- and right-sided abdominal cases occur with approximately equal frequency in ponies. Approximately half the right-sided unilateral abdominal cases have the epididymal tail descended while only 20 per cent of the left-sided cases do. These findings are briefly discussed. From their analysis of inguinal cryptorchidism the authors conclude that it is a relatively more complex phenomenon with incidence changing with age as well as breed. Right-sided retention predominates in young ponies, probably being an extreme expression of testicular hypoplasia, but in older ponies and in other types of horse, retention occurs equally on the left and right.

Abdomen↗

PubMed1992

Changes in AIDS incidence trends in the United States.

Estimating the current prevalence of human immunodeficiency virus (HIV) and projecting the future incidence of AIDS require that trends in incidence be analyzed and interpreted. We analyzed AIDS incidence trends in the United States by exposure category and selected demographic factors. In 1987, the trend in United States AIDS incidence changed as growth in the number of cases diagnosed per quarter began to decline. The slowing in growth is due in large part to a plateau in quarterly incidence in men who have sex with men in the New York City, San Francisco, and Los Angeles metropolitan statistical areas (MSAs), and in injecting drug users in the New York City MSA and New Jersey. Incidence has also reached a plateau in both adult/adolescent and pediatric blood and blood product recipients. Quarterly U.S. AIDS incidence was roughly constant during 1990, but appears to have increased to a higher level during the first half of 1991. The variation in incidence trends among subgroups suggests that several factors have affected the trend in total incidence and that the burden of severe symptomatic HIV disease may be shifting.

Acquired Immunodeficiency Syndrome↗

PubMed1992

Predicting AIDS deaths and prevalence in Australia.

OBJECTIVE: To describe a method for predicting deaths from, and the prevalence of, the acquired immunodeficiency syndrome (AIDS) in Australia and to obtain ranges of projections for the next five years based on data observed to 30 September 1989 and reported by January 1990. The projections are important components of planning for future health-care needs. PATIENTS: All patients with AIDS in Australia who were known to the National Centre in HIV Epidemiology and Clinical Research. The data used in the analysis were date of diagnosis of AIDS, date of death if the patient had died, and State or Territory of diagnosis. RESULTS: For Australia as a whole, the doubling time of AIDS incidence changed from 0.83 years before mid 1987 to 4.34 years after that time. Five hundred and seventy patients were diagnosed with AIDS to 30 June 1987 of whom 487 had died by 30 September 1989 and the estimated mean survival time was 1.36 years. Of 1037 patients diagnosed with AIDS after June 1987, 352 had died and the estimated mean survival time was 2.42 years. Combining the estimated survival distribution with the projected new cases of AIDS, we forecast that there will be between 530 and 680 deaths from AIDS in Australia in the year mid 1991 to mid 1992. Estimated cumulative deaths to mid 1994 range from 3390 to 4250. We predict that there will be between 1370 and 1850 people living with AIDS during the year ending mid 1992, and that this number will increase to between 1760 and 2830 for the year ending mid 1994. We also predict that the prevalence of AIDS in New South Wales will lie between 820 and 1620 for the year ending mid 1994, and that the prevalence in Victoria will lie between 270 and 740 in the same year. CONCLUSIONS: Any value in the range of predictions for AIDS incidence we give is equally likely and there is good agreement with the data now observed from mid 1989 to mid 1990. The dramatic increase in the doubling time is the result of a number of factors predicted by epidemic theory and the availability of treatment, zidovudine in particular. Our estimates of deaths and prevalence have been influenced by the quality of the available death data. The observed number of deaths in the year mid 1989 to mid 1990 has exceeded the number forecast for that year. Substantial improvements in survival were associated with the introduction of zidovudine into clinical practice in mid 1987 but the death rate has risen rapidly again in the very recent past, possibly due to patients becoming increasingly refractory to treatment with zidovudine (before or after a diagnosis of AIDS). Our approach to forecasting can be adjusted to accommodate a transient effect of treatment as further data accumulate.

Acquired Immunodeficiency Syndrome↗

PubMed1991

Abnormalities of the retinoblastoma gene in the pathogenesis of acute leukemia.

The retinoblastoma-susceptibility (Rb) gene is an antioncogene that is frequently altered in retinoblastomas, sarcomas, and some epithelial tumors. We examined the structure of the Rb gene by Southern blotting in 215 cases of leukemias and lymphomas of diverse phenotype and in 15 leukemic cell lines. In selected cases Rb protein expression was examined with specific monoclonal antibodies. Structural abnormalities of the Rb gene with absent protein expression were frequent in all types of human acute leukemia, but were particularly common (27% incidence) in M4 and M5 myeloid leukemia with monocytic differentiation and in Philadelphia chromosome (Ph1)-positive leukemia of lymphoid phenotype (11% to 29% incidence). Changes in Rb were observed early in the transition to acute leukemia in cases of myelodysplastic syndrome and in the accelerated phase of chronic myelocytic leukemia in transition to blast crisis. In one case, molecular changes in Rb could be correlated with leukemia remission and relapse. We conclude that the Rb antioncogene is commonly involved in the evolution of human acute leukemias, particularly in those of a monocytic phenotype and in lymphoid leukemia in which there is an antecedent alteration of the Ph1 chromosome.

Acute Disease↗

PubMed1991

Prevention of stroke--a report from collaboration project between Zagreb and Barcelona.

Cerebrovascular disease (CVD) is the main killer in the modern society and the most frequent cause of death and disability. According to the experiences of highly developed Western countries, especially of the U.S.A., the incidence of stroke can be reduced by the development and introduction of preventive actions and change of life style. Incidence of cerebrovascular disease is high in Croatia as well as in Spain (46% in the 46-59 age range) with an increasing tendency in younger population. As prevention is the only way of CVD incidence reduction, it is indispensable to organize an integral preventive neurologic network. Within the W.H.O. project "Health for All by the Year 2000 and the project "Zagreb"--Healthy City" a preventive action under the slogan 'With perfect brain and veins--enjoy the healthy days', has been organized with the aim to reduce the incidence of stroke for 20% during the following 10-year period. A standardized work of preventive network in Zagreb has also been established in Barcelona as a joint work. Using the interdisciplinary counselling approach, medical teams are still making examinations. In Zagreb Center for Neurological Sciences and Brain Research, data of risk factor distributions and trends of stroke incidence changes have been collected and the results have been analyzed. The Zagreb Center has also become a center for continuous evaluation and further planning. In this article functions of preventive centers, the preventive standardized protocol and structural and functional preventive network are introduced. The results of preventive action in Zagreb are also briefly presented.

Aged↗

PubMed1990

Forecasting the number of AIDS cases: an analysis of two techniques.

Two methods used to forecast AIDS cases--trend analysis and back calculation--are examined in this paper. I forecast AIDS cases using trend analysis with data on the number of cases reported between January 1984 and March 1990. Forecasts using back calculation methods are based on the assumption that the progression rates from HIV to AIDS slowed in 1988 due to the use of AZT and aerosol pentamidine. With both methods, reasonable models yield widely different forecasts. Analysis also is hampered by a lack of information about the basic determinants of AIDS incidence, changes in the definition of AIDS, underreporting, and uncertainty about the effect of the use of prophylactic drugs. It is not possible to establish confidence limits around forecasts that take into account these sources of biases, and it is important that those who use AIDS forecasts be aware of these uncertainties.

Acquired Immunodeficiency Syndrome↗

PubMed1977

[Determination of the importance of environmental factors in human cancer: the role of epidemiology].

The evidence in support of the assertion that 80% of human cancers are of environmental origin is reviewed. The environment is used in its broadest sense and is taken to include the widespread general exposures of air and water pollution, the work environment, exposures resulting from personal choice such as smoking and drinking, and the diet. Several examples are chosen to show that a wide range of environmental agents can cause cancer. Consideration of descriptive epidemiological data relating to migrants, geographical variation in incidence, changes in risk over time, correlation studies, clusters and case reports, supports an environmental etiology for many cancers the cause of which is at present unkown. The same data can be used to show that a large proportion of cancer is likely to be due to environmental factors. If the lowest rate observed in a series of populations be regarded as representing a residuum of cancers due to non-environmental causes then it is possible to imagine a hypothetical population with a very low rate indeed. However, it is unlikely that such a level could be achieved even if all causal mechanisms were understood as it is possible that factors leading to one cancer may protect against another. Until evidence to the contrary is aduced it is held that the vast majority of human cancers are due to the environment: the reasons why there has been reluctance to accept this conclusion are discussed.

Animals↗

PubMedDate not supplied

Rising trend of reported gonorrhoea and urethritis incidence in Burkina Faso from 1978 to 1983.

Rising trends in gonorrhoea and urethritis infection rates are being reported from most African countries. We investigated infection trends in Burkina Faso from 1978 to 1983, using data provided by the Ministry of Health. The data included monthly distribution of cases to permit analysis of seasonal variations, average number of reported cases per four-week period to estimate the yearly trend, actual number of reported cases per four-week period to measure the secular trend, and a single-period moving average as a more stable measure of disease occurrence. Seasonal trends demonstrate that the average number of reported cases of gonorrhoea is highest from January to May, declines from May to July, and levels off from August to December. The yearly trend from 1978 through 1983 increased by an average of 10.2% per year (P less than 0.001). The geographical distribution of the incidence in 1983 indicates that the northern region around Dori has the greatest number of reported cases. This high frequency is likely to reflect the severity of the problem among the nomads of the north since reporting would probably be low from this under-served and under-populated region. Peak incidence is correlated with the harvest season and may reflect increased sexual contacts among young, mobile men. The rising rate of gonorrhoea/urethritis infection is an especially urgent matter, given the expanding epidemic of human immunodeficiency virus in West Africa.

Burkina Faso↗

PubMed1991

Epidemic of caesarean sections in Brazil.

Brazil has one of the highest rates of caesarean section in the world. Patterns of caesarean sections were studied in a cohort of 5960 mothers followed from 1982 to 1986 in southern Brazil. Overall, 27.9% were delivered by caesarean section in 1982, this proportion being 30% for nulliparae, 80% for second deliveries when the first was by caesarean, and over 99% for third births when the first two were by caesarean. Socioeconomic status and requests for sterilisation by tubal ligation were important underlying factors. 9.4% of the women were sterilised during a caesarean section (3.7% in the lowest income group and 20.2% in the highest). 31% of women who had had their first child by a caesarean section and who were having a second operative delivery were sterilised. The high rates of caesarean sections and accompanying sterilisations reflect the lack of appropriate reproductive and contraceptive policies in the country.

Brazil↗

PubMed1990

Oral contraceptives and rheumatoid arthritis: new data from the Royal College of General Practitioners' oral contraception study.

From data available at April 1987 it was found that the standardised risk ratio for rheumatoid arthritis between current users of oral contraceptives and never users was 0.82 (95% confidence interval 0.59 to 1.15); the ratio between former users and never users was 0.94 (95% confidence interval 0.72 to 1.22). Important secular trends have occurred within our study population. The incidence of rheumatoid arthritis among former and never users has declined over the past two decades. Current users have not experienced this temporal trend, and the ratio between current and never users has, therefore, approached unity. These secular changes may explain why some studies have found that oral contraceptives have a protective effect, while others have been unable to show such an effect.

Adult↗

PubMed1978

Changes in the incidence of acute gonococcal and nongonococcal salpingitis. A five-year study from an urban area of central Sweden.

The incidence of acute gonococcal and nongonococcal salpingitis for a five-year-period (1970--74) was studied retrospectively in an urban area of central Sweden. The investigation was undertaken to see if the reported decrease of gonorrhoea in Sweden had been followed by a change in the incidence of gonococcal salpingitis--the most common complication of gonorrhoea. The study showed that the relative incidence of acute gonococcal salpingitis had decreased even more than urogenital gonorrhoea and these findings thus indicate a real decrease of gonorrhoea. At the same time there were more patients with nongonococcal salpingitis. During the period of the study the gonococcal complement-fixation test (GCFT) gave positive results in 40% to 80% of the patients with gonococcal salpingitis. The yield with this test was only 4% in patients with nongonococcal salpingitis during 1970 but it increased successively and was 23% in 1974. This increase was statistically highly significant (P less than 0.001).

Acute Disease↗

PubMed1992

Sex steroid hormones and breast cancer: is there a link with oral contraceptives and hormone replacement therapy?

OBJECTIVE: To determine whether use of sex steroid hormones for contraception and hormone replacement therapy alters the risk of breast cancer, and whether the risk varies with their composition, duration of use, the period of a woman's life when the hormones are used, and after successful treatment for breast cancer. DATA SOURCES: The results of important epidemiological reports, readily available from the English literature and published since 1981, were evaluated, using reports of basic scientific work as a background to the problem. STUDY SELECTION: An attempt was made to obtain most of the relevant reports. Twenty case-control and seven cohort studies were available on the oral contraceptive pill (OCP) and eleven case-control and five cohort studies on hormone replacement therapy (HRT). DATA EXTRACTION: The relative risk estimates for breast cancer (and their 95% confidence intervals) determined by each report were tabulated according to the specific conditions of analysis, for example users under age 25, duration of use. Results by meta-analysis from previous studies were also used to determine risk. A significant positive association was present when the risk estimate exceeded 1.0 and the 95% confidence interval did not cross 1.0. DATA SYNTHESIS: Among OCP users, the vast majority of reports showed no significant risk of breast cancer--overall, longest duration of use, and use before first full-term pregnancy. However, a positive association between breast cancer and users under age 25 was found in three of eight reports. Similarly, the majority of reports showed no significant risk of breast cancer among HRT users, overall as well as in relation to duration of use and interval since first use. There was no increased risk with additional progestogen; it may be protective. An improved prognosis was found in users who developed breast cancer. On the limited data, use of hormones for postmenopausal symptoms did not appear to be harmful to women who had been successfully treated for breast cancer. CONCLUSIONS: The review revealed good evidence that use of sex steroid hormones had no significant effect on the risk of breast cancer, whether given for contraception or hormone replacement. There was some concern about increased risk with prolonged use of the OCP, especially in younger women. At present, use of these hormones is a matter of informed choice, with individual considerations of the risk-benefit ratio.

Adult↗