A case-control study of Hodgkin's disease in Israel.

Jewish residents of Israel in 1960-72 with Hodgkin's disease (HD) were compared with controls drawn from the general population. The controls were individually matched by sex, age, origin, and date of immigration. The comparison showed a significant association between HD and parental consanguinity and pointed to the possible etiologic role of recessive inheritance. Females with HD tended to have a lower parity than did their controls. Associations between HD and a high educational level and the presence of a flush toilet in the childhood home were significant and gave limited support to the hypothesis that a high standard of living in childhood increases the risk of subsequent HD. Tonsillectomy and a history of work with wood or trees were significantly associated with mixed cellularity but not with other histologic subtypes. Differences between patients with HD and controls with respect to cigarette smoking, exposure to animals, marital status, previous blood transfusions or jaundice, contact with asbestos, residual or occupational mobility, or other characteristics were not significant.

Estimated number of loci for autosomal recessive severe nerve deafness within the Israeli Jewish population, with implications for genetic counseling.

Deafness occurs in about 1 per thousand live births, and at least 50% of congenital deafness is hereditary. The aim of this study was to examine the number of loci for recessively inherited severe nerve deafness of early onset within the Israeli population and to compare the results to those obtained in other populations. The Jewish population in Israel originates from many countries and may be divided into Sephardi, Eastern and Ashkenazi Jews, and the matings will be intraethnic or interethnic. Data were obtained on 133 deaf couples who lived in the Tel Aviv area, through the files of the Helen Keller Center. Causes of deafness in the spouses were studied and data on their children were obtained. Among 111 couples who had recessive or possibly recessive deafness and had at least 1 child, there were 12 with only deaf children and 5 with both deaf and hearing children. The number of loci for recessive deafness in the whole group was estimated at 8-9. Intraethnic and interethnic matings gave an estimate of 6.7 and 22.0 loci, respectively, which indicates that within populations fewer loci exist with recessive mutations for deafness than between populations. It could be shown that the sharing of loci between spouses decreased with increasing geographical distance of their origin. The results provide data for genetic counseling in Israel for deaf couples who have no children or have one hearing or one deaf child.

Mortality from lymphomas in Israel, 1950-71: the possible role of environmental factors.

Mortality from malignant lymphomas among the Jewish population of Israel rose during the period 1950-71. Above the age of 50 years the annual increment exceeded that in most other countries for which data are available. The rise occurred among older adults in all population groups and among children and young adults born in Africa. It was greater among native-born than among foreign-born adults. The mortality rates among foreign-born persons varied with the continent of birth. No clear-cut relationships were found with age at immigration or period since immigration. The trends for non-Hodgkin's lymphomas parallelled those for lymphomas as a whole, but those for Hodgkin's disease varied in different population groups. The findings suggest an increase in the incidence of lymphomas, more marked among native-born than among foreign-born adults, which can be speculatively attributed to environmental factors.

Clustering of Hodgkin's disease in Israel: a case-control study.

The geographical distribution of Jewish patients in Israel with HD diagnosed between 1960 and 1972 differed significantly from that of individually-matched population controls. Significant clustering occurred in 3 regions of the country. The odds ratio expressing the greater tendency of patients to have lived in one of these regions 5-9 years before the diagnosis, as compared with that of their paired controls, was 2.4. The association with residence in a higher-risk region was not significantly modified by sex, age, period of immigration, region of birth, father's region of birth, or date of diagnosis. The association was weaker for cases with nodular sclerosis than for those with other subtypes of HD. The clustering could not be explained by available data on the characteristics and prior experience of the cases and controls. There was a significant correlation between the risk of HD in a region and the proportion of native Israelis in its Jewish population, but there were no significant correlations with a variety of other demographic, natural and socioeconomic features of the regions. There was no significant time-space interaction. The findings suggest that susceptible people living in certain parts of the country during the 1950's and 1960's had a somewhat enhanced risk of HD because of exposure to unidentified environmental factors active in those regions at that time.

Correlates of military tank simulator sickness.

A military tank driving simulator is currently widely used as a training aid for tank drivers. The purpose of this study was to investigate the relationship between possible correlates of simulator sickness and the occurrence of sickness and performance test results among simulator drivers. The average number of motion sickness-like symptoms reported after driving the simulator among subjects with a history of susceptibility to motion sickness was 3.4, significantly higher than the average of 1.6 reported among subjects who did not report previous susceptibility to motion sickness (p < 0.05). Subjects driving the simulator while screen image quality was disturbed had a longer reaction time (42.0 s) than when driving the simulator without screen interferences (18.4 s, p = 0.001). Subjects driving the simulator for a short period had the same number of symptoms as did those driving for a longer period, but had better digit symbol test results. There was no statistically significant association between the development of sickness and tank driving experience. Suggested countermeasures are expected to prevent simulator sickness among some of the simulator trainees and to make simulator training more effective.

The Turlock vitamin-mineral supplementation trial: a statistical reanalysis.

A new analysis of a randomised double-blind trial confirms the fact that vitamin-mineral supplementation has a statistically significant effect on non-verbal IQ as measured by the WISC-R test. Further studies may show if this effect is large enough to be of practical importance.

PIP: An original researcher of a double-blind study, which suggested a positive association between intelligence (IQ) and ingestion of vitamin- mineral supplements, has reanalyzed its data. The data were obtained from 440 junior and senior high school students in Turlock, California. The 4 randomly allocated treatments were a placebo and a pill with 50%, 100% and about 200% of the US recommended daily allowances (RDAs) of vitamins and minerals (about 13 pills/week for 10-13 weeks). The increase in mean nonverbal WISC-R (Wechsler Intelligence Scale for Children-Revised) IQ was linked to vitamin and mineral supplementation and could not be explained by chance occurrence (excluding noncompliers, 8.94 for placebo vs. 13.18 for 100% RDAs) (p = .0035 for 1 way ANOVA; p = .008 for multiway ANOVA). Yet, these findings did not allow one to conclude that the improvement due to vitamin-mineral supplementation was great enough to be of practical importance. Specifically, the confidence intervals showed that the influence of the 100% supplement lies between 1 and 7 points of nonverbal IQ, suggesting the magnitude of the effect may be trivial or significant. Even though the results indicated that the 100% supplement had the most effect on the nonverbal IQ, they were not conclusive. Some students within the same treatment group had higher IQ increments than others, yet no one knows what variables predict a higher response. For example, perhaps a low nutritional status when treatment begins predicts a larger IQ increment. No information existed on either the specific ingredients of the supplements that may effect increments in IQ or on the specific cognitive functions these ingredients affect. This reanalysis illustrated the need for intensive and detailed research to achieve a clearer understanding of the relationship between IQ and nutrition.

Berkson's bias revisited.

When used in a loose manner to indicate distortive effects on associations among hospitalized patients, the term Berkson's bias denotes a special case of Simpson's paradox. If, however, Berkson's independence assumption is introduced, Berkson's bias affects only the "selected" subjects and not those "left behind" and tends to decrease the odds-ratio. Generally speaking, the model is valid not only for case-control studies but also for prospective and other investigations. By introducing a time dimension the model allows for the study of changes over time in Berkson's bias.

Potential demography: a second look.

"In the late forties Hersch (1944) and Mentha (1948) introduced, respectively, the concepts of 'potential years of life' (PYL) and 'potential years of life lost' (PYLL).... Our objectives are: (a) to draw attention to Hersch's concept of potential years of life (PYL) and to illustrate its usefulness; (b) to define and illustrate three different manners of computing PYLL and to recommend one that is simple, intuitively acceptable and reasonably accurate; (c) to propose some further indicators that can be derived from PYL, PYLL and the relations between them; and (d) to discuss briefly the assumptions underlying the calculation of PYL and PYLL, and in particular those assumptions that are made in the attribution of loss in potential years of life to specific risk factors." (SUMMARY IN FRE)

An epidemiologic study of mortality among bereaved parents.

To study the health consequences of parental bereavement, we compared the mortality in two groups of bereaved Israeli parents with that in the general population. One cohort comprised the parents of all 2518 soldiers 18 to 40 years of age who were killed during the Yom Kippur War in 1973. The second consisted of the parents of 1128 men 18 to 30 years of age who died in accidents between 1971 and 1975. Both groups were followed through 1983. The comparison population was the entire population of Jewish Israelis for which sex-, age-, and calendar year-specific mortality rates were available. The 10-year age-adjusted life-table mortality was higher among fathers whose sons died in accidents rather than in war (P = 0.045), but mortality did not differ significantly between the two groups of mothers. Overall, we found no excess mortality among the bereaved parents as compared with the general population. The standardized mortality ratios for the fathers and mothers of sons killed at war were 0.91 and 0.90, respectively; for fathers and mothers whose sons died by accident, they were 1.04 and 0.91, respectively. None were significantly different from unity. There was no consistent evidence of an elevated risk of death, early or late, after the loss. Widowed and divorced parents who lost a son did have increased mortality, which was statistically significant in mothers. Our findings provide no support for the hypothesis that the loss of an adult son is associated with increased short-term or long-term mortality in married parents.

The Israel Longitudinal Mortality Study--differential mortality in Israel 1983-1992: objectives, materials, methods and preliminary results.

The main objective of this study was to investigate mortality differentials in the Israeli population, aged 40 years and above, with regard to major demographic and socio-economic characteristics, in the nine-and-a-half years following the census of 1983. The method of data collection consisted of a linkage of records from the 20% sample of the census with the records of deaths occurring until the end of 1992. The linked file contains the socio-economic and demographic data from the census, and dates and causes of death taken from the death records. This paper focuses on a systematic evaluation of the quality of the linked file, and includes a description of the characteristics of the file. Methods of verification are presented and sources of possible errors are discussed. Results of bivariate analyses of mortality differentials in relation to marital status, ethnic origin, level of education, employment, occupation and income are presented.

Risk markers for mortality among elderly men-a community study in Jerusalem.

Risk markers for mortality among elderly men were investigated in a community survey in a neighborhood of western Jerusalem. The aim was to develop a practical method of identifying men with a high risk of mortality, for use in community health services caring for the ageing and aged. Men aged 60 yr or more who had been interviewed and examined in 1969-71 were followed up for 5 yr and the characteristic of the 75 who died were compared with those of the 312 who remained alive. The results of stepwise discriminant function analyses were translated into a simple set of criteria for the identification of men with a high risk of dying within 5 yr. The sensitivity of this mortality risk indicator hazard in this sample was 72% and its specificity was 78%. The components were age, inability to work, impaired mobility, impaired memory for recent events, electrocardiographic evidence of coronary heart disease, the presence of moderate or severe illness, diastolic hypertension, hypercholesterolemia and overweight.

Mortality differentials among Israeli men.

OBJECTIVES: This study examined differentials in mortality among adult Israeli men with respect to ethnic origin, marital status, and several measures of social status. METHODS: Data were based on a linkage of records from a 20% sample of the 1983 census to records of deaths occurring before the end of 1992. The study population included 72,527 men, and the number of deaths was 17,378. RESULTS: Differentials is mortality by origin show that mortality was higher among individuals of North African origin than among those of Asian and European origin. After allowance for several socioeconomic indicators, the excess mortality among North African Jews was eliminated. Substantial and consistent differences in mortality were found according to education, occupation, income, possession of a car, housing, and household amenities. Differentials among the elderly were markedly narrower than those among men younger than 70 years. CONCLUSIONS: Some sectors of Israeli society have higher risks of death than others, including, among the male population, these who are poor, less educated, unmarried, unskilled, out of the labor force, and of North African origin.

Motion sickness-like syndrome among tank simulator drivers.

A military tank driving simulator has recently been introduced as a training aid for tank drivers in the Israel Defense Forces. Reports of nausea and vomiting among the first users of the simulator launched our investigation of the possible existence of a motion sickness-like syndrome among simulator drivers. Although the 59 subjects drove the simulator without any report of vomiting, other motion sickness-like symptoms were frequently reported. A comparison of symptoms reported after simulator and real tank driving show that dizziness, nausea, disorientation and hypersalivation were more frequently reported by simulator drivers and were of greater intensity. However, sweating and drowsiness were more prevalent among real tank drivers. The objective effect of driving the simulator was evaluated by instability and performance tests that were conducted before, during and after driving the simulator. A greater decrement in test results was observed among subjects reporting higher frequency of motion sickness-like symptoms.

Comparison of head circumference in an Israeli child population with United States and British standards.

The head circumference (HC) growth pattern of infants from 1 to 24 months of age was studied in a Jerusalem community. The means of HC of the study population are smaller for each age and sex group than those of the National Center of Health Statistics, USA reference population, London children and the Nellhaus standard. The regression of HC on length explains about 20% of the variance. In an analysis of variance controlling for social class, birth order and length, the differences by region of origin of the mother were not significant. The smaller HC of the study population is probably due to these children being shorter and lighter than the above-mentioned western populations. Malnutrition as a factor for small HC was excluded.

Clustering of chronic disorders--a community study of coprevalence in Jerusalem.

Associations between chronic disorders were appraised in a community survey in western Jerusalem in order to identify clusters of mutually related conditions. Two sets of interrelated diseases were observed. The first comprised coronary heart disease, hypertension, diabetes and their complications. The second included migraine and other chronic disorders whose diagnosis was largely based on subjective symptoms. The presence of these complaint-based disorders was associated with a high prevalence of emotional symptoms, with reported difficulties in the life situation, and with frequent doctor visits. The design of appropriate programs of preventive and therapeutic intervention for this cluster of disorders remains an important challenge.

The incidence of cervical cancer and duration of oral contraceptive use.

In a prospective study carried out on a cohort of 17,942 women belonging to the Kaiser Foundation Health Plan and living in suburban communities of the San Francisco Bay Area, a positive association was found between the incidence of cervical carcinoma and total duration of oral contraceptive use. The association was established while controlling for the effects of age, education, and selected infections. The association persists when incident cases of dysplasia are added to those of carcinoma. A further study, in which covariates relating to sexual behavior will also be taken into account, is in progress.

Rates of sickness absenteeism among employees of a modern hospital: the role of demographic and occupational factors.

Sickness absenteeism, of hospital employees particularly, is a problem of concern due to its negative economic and morale impacts. The aim of the first stage of the study was to identify according to some demographic (sex, age, marital status) and occupational (occupational group, duration of hospital employment) variables those groups of hospital employees who are at higher risk of sickness absenteeism. A comparison with the data of the study performed in the same hospital about 15 years ago showed a rise in the duration of absences with a simultaneous reduction in their incidence. Sickness absenteeism was higher among female, mainly unskilled, workers, presently or previously married, aged from 45 to 60, and employed in the hospital for over ten years. Continuous social and medical surveillance of these employees is suggested as a promising way of reducing sickness absenteeism.

A community health study in Jerusalem. Design and response.

A longitudinal community health study was commenced in a neighborhood of western Jerusalem in 1969. Its main aims were the investigation of etiologic factors in selected common diseases and disabilities, the development and testing of epidemiologic tools for use in community diagnosis, the provision of a factual basis for decisions concerning community health care for the population studied, and the use of the findings in an evaluation of the effectiveness of community health care. In the first round, 90% of residents 25 or more years old were interviewed and 81% were examined. Among children under 15 years of age, the corresponding rates were 94 and 83%. Response was low among persons in the age range 15 to 24 years, especially males. People who were concerned about their health were readier to be examined. Response was not related to region of birth, education or other variables. The possible bias introduced by nonresponse appeared to be small except in the age group 15 to 24 years.