A modified random-effect procedure for combining risk difference in sets of 2×2 tables from clinical trials

Summary Meta-analyses of sets of clinical trials often combine risk differences from several 2×2 tables according to a random-effects model. The DerSimonian-Laird random-effects procedure, widely used for estimating the populaton mean risk difference, weights the risk difference from each primary study inversely proportional to an estimate of its variance (the sum of the between-study variance and the conditional within-study variance). Because those weights are not independent of the risk differences, however, the procedure sometimes exhibits bias and unnatural behavior. The present paper proposes a modified weighting scheme that uses the unconditional within-study variance to avoid this source of bias. The modified procedure has variance closer to that available from weighting by ideal weights when such weights are known. We studied the modified procedure in extensive simulation experiments using situations whose parameters resemble those of actual studies in medical research. For comparison we also included two unbiased procedures, the unweighted mean and a sample-size-weighted mean; their relative variability depends on the extent of heterogeneity among the primary studies. An example illustrates the application of the procedures to actual data and the differences among the results. This research was supported by Grant HS 05936 from the Agency for Health Care Policy and Research to Harvard University.     

Sexual identity in the ghetto

The more things change, the worse they get.Presented April 18, 1991, Duke University, at the Department of Psychiatry's Grand Rounds, this paper condenses, integrates and updates the author's earlier publication. Acknowledgement and thanks for funding and professional sponsorship of the four research studies this paper draws from are selectively due to the Eugene and Agnes E. Meyer Foundation, the Edgar Stern Family Fund, The National Institute for Mental Health, the Baltimore-Washington Institute for Psychoanalysis and the Department of Psychiatry, Children's Hospital National Medical Center.     

Differences in preferred level of arousal in two sub-groups of problem gamblers: A preliminary report

Twelve problem poker machine players and thirteen horse race gamblers (20 males and 5 females; age range 28–69) completed a series of questionnaires which assessed levels of anxiety, their preferred state of arousal and their motivations to gamble. As predicted, problem poker machine gamblers were found to be more anxious and reported avoiding arousal more frequently than the horse race gamblers. Alternately, problem horse race gamblers were found to prefer heightened levels of arousal and appeared to gamble to achieve these optimal levels of arousal. However, there was no difference between the groups on proneness to boredom. The present results provide evidence which is consistent with the Reversal theory and its application to the field of problem gambling.     

Screening for patients with alcohol problems: severity of patients identified by the CAGE.

Primary care physicians are well situated to identify patients with substance abuse problems and motivate them to seek appropriate assistance, but active programs are the exception. A study in a community setting was undertaken to assess the CAGE (the first letters of key words in a series of four questions about drinking: cut down; annoyed; guilty; and eye-opener), instrument in the routine screening for alcohol problems in both new and established patients. The screening process identified subjects for a pilot evaluation of a motivational interview designed to encourage problem-solving behavior. This article focuses on the screening results and the use of the CAGE instrument. During June and July of 1990, 687 patients of two primary care physicians belonging to a large group practice were asked to complete a health questionnaire that included the CAGE. Those who responded affirmatively to at least two of the four CAGE questions were requested to participate in follow-up assessment of problems associated with alcohol and health. The type and severity of alcohol problems experienced by patients who scored positive on the CAGE are described. Prevalence of a positive score on the CAGE was 8.6 percent with males, smokers, and blue collar and unemployed persons being more likely to score positive. The positive predictive value was .68. Primarily, persons with moderate alcohol problems were identified. Results show that the CAGE instrument is a useful screening device for identifying those with mild to moderate substance abuse problems, increasing the opportunity for intervention prior to serious medical complications. The instrument is easily administered, and has demonstrated relatively high levels of sensitivity and specificity. When combined with assessment and motivational interviews, the CAGE shows promise in the secondary prevention of substance abuse and related health problems.     

EFFECTS OF A PREPAID NONMONETARY INCENTIVE ON RESPONSE RATES AND RESPONSE QUALITY IN A FACE-TO-FACE SURVEY

We conducted a randomized experiment on a face-to-face interviewsurvey in order to test the effects on response rates of a prepaidnonmonetary incentive. Results showed a statistically significantincrease in response rates, mostly through reduction in refusalrates, in the half sample that received the incentive (a gift-typeballpoint pen) as compared with a no incentive control group.The effect appears to be due to greater cooperation from incentiverecipients at the initial visit by an interviewer. Unexpectedly,the incentive group also showed a significantly higher rateof sample ineligibility, possibly due to easier identificationof vacant residences or nonexistent addresses. In addition,evidence suggests greater response completeness among respondingincentive recipients early in the interview, with no evidenceof increased measurement error due to the incentive.     

EDITH WHARTON'S SICK ROLE

In this article, we conduct a textual analysis of Edith Wharton's 1911 novel, Ethan Frome . We offer three readings. The first presents Wharton's account of illness through a framework developed foru decades later by Talcott Parsons. Wharton's sick role was less medico-centric than Parsons; it emphasized the importance of class, gender and community in defining and legitimizing the sick role. Our second reading explores the socially constructed nature of roles in illness. The sick role as portrayed by Wharton is not the social fact later conceived by Parsons, but a social construct with no determinate reference beyond that which the local community is willing to grant it. Our third reading examines the social context, particularly the power relations, within which this story of illness has been constructed.     

Public Perceptions about Food Safety in the United States and Japan1

Abstract Consumer concerns over pesticide residues and food additives have been growing in industrialized societies, including the United States and Japan. However, little comparative research has been carried out to determine which household characteristics may be significantly associated with these heightened concerns, and whether or not the same factors are useful for understanding variation in these worries in more than one society. This paper examines food safety attitudes in Seattle, Washington, and Kobe, Japan, and discovers that while the absolute level of expressed concern is higher in Kobe, the predictive power of household characteristics in explaining attitudinal differences within countries is similar. Implications for rural areas and future research on family structures in capitalist societies are discussed.     

MONEY DEMAND DURING HYPERINFLATION AND STABILIZATION: BOLIVIA, 1980–1988

This paper examines the demand for money in Bolivia during the 1980s, a decade of extreme instability with annual inflation rates reaching over 20,000 percent, and a subsequent stabilization, with annual rates falling to less than 25 percent and remaining so for more than five years.
Our empirical analysis makes use of error-correction approaches, time-varying-parameter estimation with Kalman filtering, and GARCH models of expected inflation and inflation variance. We find that expected inflation and inflation uncertainty both matter for money demand. Time-varying estimates show that the reaction to monetary disequilibria was significantly faster during hyperinflation.     

TESTING SPHERICITY UNDER A MIXTURE MODEL

The robustness of Mauchly's sphericity test criterion when sampling from a mixture of two multivariate normal distributions is studied. The distribution of the sphericity test criterion when the sample covariance matrix has a non-central Wishart density of rank one is derived in terms of Meijer's G-functions; its distribution under the mixture model is then deduced. The robustness is studied by computing actual significance levels of the test under the mixture model using the critical values under the usual normal model.