Urban birth and residence as risk factors for psychoses: an analysis of 1880 data.

It is known that social drift to cities increases the urban prevalence for severe mental illnesses. Recent studies in England and Sweden have reported that being born in, or raised in, an urban area is also a risk factor for later developing schizophrenia. The present study utilized 1880 census data, the most complete enumeration of severely mentally ill individuals ever done in the United States, to examine the association of urban residence and severe mental illnesses. Individuals identified as having one of seven forms of 'insanity' (n = 91959) were allocated to their county of origin (n = 2661) in the census. Rates of 'insane' persons per 1000 population were calculated for each county. The counties were then divided by degree of urbanization based on the largest cities and the percentage of population living in towns of 4000 or more. The point prevalence of 'insanity' in the United States as a whole in 1880 was 1.8 per 1000. There was a significant association between 'insanity' by county and degree of urbanization, with odds ratios of 1.66 for urban, 1.46 for semi-urban, and 1.44 for semi-rural, and 1.37 for rural, using completely rural counties as a baseline. Most completely rural counties with high rates included mining camps, lumbering camps, or fishing villages, and not farming areas. In addition to urban drift, urban birth and residence appear to be risk factors for developing severe mental illnesses. Psychological and biological explanations have both been proposed. However, recent studies reporting winter birth and urban birth or residence as synergistic risk factors favor the latter.

Prenatal origin of schizophrenia in a subgroup of discordant monozygotic twins.

Neuropathological, obstetrical, and epidemiological evidence increasingly suggest that some cases of adult-onset schizophrenia have prenatal or neonatal etiological roots. We evaluated the developmental histories of 23 monozygotic twin pairs discordant for schizophrenia to determine when they markedly and permanently began diverging from each other in motor skills or unusual behavior. Seven of the twins (30%) who later developed schizophrenia had become permanently different from their cotwins by age 5 years. The early divergence group differed from the others by multivariate tests (p = 0.002) for within-twin pair effects and by univariate tests for physical anomaly scores (p = 0.01), total finger ridge counts (p = 0.001), family history of psychosis (p = 0.004), and serious perinatal complications or low birth weight (p = 0.05). It is concluded that some cases of adult-onset schizophrenia are associated with prenatal events, which may include neurodevelopmental abnormalities or specific insults such as anoxia or infectious agents.

Handedness in twins with schizophrenia: was Boklage correct?

Boklage's report of increased non-right handedness among monozygotic twins with schizophrenia has been cited as evidence to support an association of abnormal brain lateralization with the development of schizophrenia. The present study found no such association. Two previous attempts to replicate Boklage's findings (Luchins et al. 1980; Lewis et al. 1989) also reported little support. Studies of twin handedness do not appear to support an association of brain lateralization and schizophrenia.

Seasonality of schizophrenia and stillbirths.

A study of the birth pattern of 30,467 patients with schizophrenia and 428,406 stillbirths in New York State showed a significant winter-month excess in both schizophrenia births (p = 0.0000) and stillbirths (p = 0.0000). Excess births of individuals with schizophrenia in November and December provided additional evidence to refute the age-incidence explanation for the observed seasonality. Time series spectral analysis showed coherence in the pattern of schizophrenia births and stillbirths of 0.898 (p < 0.003) with schizophrenia births preceding stillbirths by 13 days. These results suggest that a common etiological seasonal factor affects a subgroup of births of individuals who later develop schizophrenia and a subgroup of stillbirths. Nutritional factors, temperature, and infectious agents known to cause both central nervous system disease and stillbirths are possible candidates.

Improving the quality of emergency department documentation using the voice-activated word processor: interim results.

We examined whether voice-activated word processors provide an acceptable means for emergency physicians to create medical records. Our study addressed three areas of inquiry: whether physicians can be induced to try this new technology, whether they will continue to use it after outside technical support is withdrawn, and the factors contributing to adoption and substantial use of voice-activated computers by practicing emergency physicians. This paper presents findings from the first half of the study, reflecting physicians' reported experiences while receiving onsite training followed by technical support for three months after system installation. Based on preliminary assessments, the keys to successful use appear to include physician and group commitment, acceptance of a steep learning curve, and flexibility in adapting the computer software and/or practice habits.

Hypertension as a risk factor.

Hypertension has been demonstrated to be a clear risk factor for CHD. The finding that hypertension is a risk factor has been demonstrated in observation studies, actuarial data and clinical trials. The relationship between blood pressure and CHD is strong. As blood pressure rises, risk for cardiovascular events increases. This is true for both sexes, for blacks and whites, and for all age categories. Clinical trials, both large and small, have demonstrated that lowering blood pressure can reverse the risk and reduce morbidity and mortality. This cause-and-effect relationship has been replicated consistently, and there is not one well-controlled trial of adequate size that has failed to show this finding. It is important to know which concept of risk to use in developing hypertensive programs. The concept of relative risk is useful to determine whether a public health program is needed within a population, but it has less value in identifying which subset of the population in which to intervene. In essence, relative risk is used to mandate a program but cannot determine where the program should be directed. Hypertension attributable risk describes which individuals are at greatest risk and serves to guide planners as to which groups have the greatest mortality once blood pressure becomes elevated. Population attributable risk becomes the most useful tool in identifying or locating those communities of highest-risk individuals.

The seasonality of schizophrenic births: a reply to Marc S. Lewis.

Lewis contends that the previously demonstrated finding of seasonality of schizophrenic births is a statistical artifact due to the age-incidence effect. If Lewis is correct, then (1) January should have the highest schizophrenic birthrate, (2) December should have the lowest schizophrenic birthrate, (3) the Southern Hemisphere should show the same pattern as the Northern Hemisphere, and (4) the age-incidence effect should be more marked in younger age cohorts. None of these findings have been borne out by studies to date. It is concluded that the seasonality of schizophrenic birthrates is a replicable finding, and should be considered one of the more intriguing clues to the etiology of this disease.

Epidemiologic considerations in defining hypertension.

Definitions of hypertension have historically been based on at least one of three concepts. The first approach identifies thresholds of hypertension based on the frequency of occurrence in the population. The statistical approach designates a point in the distribution (e.g., the 95th percentile), as the threshold for hypertension. This distribution method identifies different limits for hypertension depending on the age, sex, and race, of the population, all of which affect the average pressure. Although distribution curves do not by themselves identify thresholds for intervention, they are useful for examining changes in population groups over time. The second approach to defining hypertension relates pressures to the risk of morbidity and mortality and is characterized by a continuously graded curve with no clear categorical thresholds. Studies correlating both diastolic and systolic pressures with cardiovascular complications demonstrate continuous risks from lowest to highest values for both sexes, all ages, and both blacks and whites in the United States. The blood pressure-risk relationship provides a compelling rationale for treatment but does not by itself define thresholds for the initiation of therapy. The third approach uses data from clinical intervention trials to identify thresholds where the benefits of therapy outweigh the costs and side effects of long-term treatment. Although results of large randomized trials have clearly demonstrated reductions in morbidity and mortality by lowering blood pressures, consensus on the lowest threshold within the mild range for which antihypertensive drug treatment is recommended has not been reached. Because an optimal definition of hypertension must encompass all three approaches and the resultant classification scheme must be sufficient for all purposes, attempts to refine and improve upon the presently recommended thresholds will undoubtedly continue.

Hypertension knowledge, attitudes, and behavior: 1985 NHIS findings.

Data from the Health Promotion/Disease Prevention Supplement to the 1985 National Health Interview Survey provide an indication of progress made toward achieving the 1990 objectives for the nation. Survey results showed remarkably high levels of knowledge concerning the increased risks associated with uncontrolled high blood pressure. Nine of 10 adults in the United States knew that high blood pressure increases the risk of heart disease, and 3 of 4 knew that high blood pressure is the most significant risk factor for stroke. The majority of both the general public and the subgroup of the population identified as hypertensives reported knowing the results of their last blood pressure measurement; and, most importantly, almost two-thirds of the identified hypertensives reported that their pressures were under control at last measurement. Data examining professional advice, given and acted upon to achieve blood pressure goals, show that almost two-thirds of the hypertensives currently report taking antihypertensive medication. Results also suggest a degree of willingness by both professionals and hypertensives to attempt nondrug approaches to controlling pressures. The large majority of hypertensives who were advised by a health professional to cut down on sodium, lose weight, and exercise reported they were following this advice. These findings will be used to further refine high blood pressure education strategies and advance the progress toward meeting the 1990 hypertension objectives.