Prodromal unstable angina in acute myocardial infarction: prognostic value of short- and long-term outcome and predictor of infarct size.

BACKGROUND: An estimated 50% of patients with myocardial infarction have prodromal unstable angina. There is controversy over whether prodromal unstable angina identifies a group of patients at lower risk of short- and long-term death and the clinical importance of recording this event. METHODS: Of 207 patients enrolled at a single Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) site, 196 survived the 24 hours after presentation, achieved peak creatine kinase MB concentrations, and were classified as having either abrupt symptom onset or prodromal unstable angina in the 2 weeks before myocardial infarction. Creatine kinase MB peak was used to categorize infarct size as aborted myocardial infarction, minor myocardial damage, or extensive myocardial injury. Follow-up was performed at 24 hours, 30 days, 1 year, and 5 years. Multiple variables, including prodromal unstable angina, time to treatment, age, sex, previous infarction and infarct location, were analyzed for predicting infarct size. Also, these variables plus peak creatine kinase MB level and a combined variable of prodromal unstable angina and peak creatine kinase MB level were examined for predicting survival. RESULTS: Mortality rate was 2.5% within 24 hours, 9.0% at 30 days, 13.5% at 1 year, and 27.1% at 5 years. Patients categorized as either aborted infarction or minor myocardial damage were significantly more likely to have prodromal unstable symptoms (81.3% vs 51.2%, P <.001) and better survival at each follow-up period. Prodromal presentation was the most significant predictor of infarct size category (P =.001). Five-year survival was predicted by age (P <.0001), peak creatine kinase MB level (P =.007), infarct location (P =.009), the combined variables (P =.029), and prodromal unstable angina (P =.017). Prodromal unstable angina had the highest odds ratio for 5-year survival at 3.83 (95% confidence interval 1.27-11.47). CONCLUSIONS: Prodromal unstable angina is a strong predictor of infarct size and survival. Recognizing prodromal unstable angina is important for clinically assessing prognosis.

Alcohol consumption and mortality. I. Characteristics of drinking groups.

AIMS: This is the first of a set of three papers evaluating drinking status and mortality risk. Analyses of multiple studies describe associations of drinking patterns with characteristics hypothesized to confound the relationships between drinking status and mortality. Characteristics which both significantly differentiate drinking groups and are consistent across studies would suggest that mortality studies not controlling for them may be compromised. DESIGN AND PARTICIPANTS: Associations are evaluated from the raw data of 10 general population studies which contained mortality data. Long-term abstainers are compared to former drinkers, long-term abstainers and former drinkers are compared to light drinkers (by quantity, frequency and volume in separate analyses) and moderate to heavy drinkers are compared to light drinkers. Tetrachoric correlation coefficients assess statistical significance; meta-analysis determines if associations are homogeneous across studies. MEASUREMENTS: Measures of alcohol consumption are quantity, frequency and volume; long-term abstainers are differentiated from former drinkers. Multiple measures of health, social position, social integration and mental health characteristics are evaluated. FINDINGS: Across studies, adult male former drinkers are consistently more likely to be heavier smokers, depressed, unemployed, lower SES and to have used marijuana than long-term abstainers. Adult female former drinkers are consistently more likely to be heavier smokers, in poorer health, not religious, and unmarried than long-term abstainers. Both types of abstainers tend to be of lower SES than light drinkers and report poorer health (not consistent). Female abstainers are more likely to be of normal or overweight than light drinkers. CONCLUSIONS: Characteristics of two groups of abstainers, other than their non-use of alcohol, may confound the associations found between drinking and mortality risk.

Alcohol consumption and mortality. II. Studies of male populations.

AIMS: This is the second of a set of three papers evaluating drinking status and mortality risk. Analysis of eight general population surveys of men evaluated all-cause mortality rates by drinking pattern. DESIGN AND PARTICIPANTS: Raw data from three studies of youth and five studies of adults were evaluated. Logistic regression models controlled for confounding characteristics. Meta-analysis combined study results. MEASUREMENTS: Drinking pattern was alternatively defined by quantity, frequency and volume of drinking. Final models included drinking pattern (as well as abstinence in the youth models and long-term abstainers and former drinkers in adult models), age and other confounding variables. Models also evaluated interactions of age and, respectively, long-term abstinence and former drinking. FINDINGS: No evidence was found for the hypothesis that abstinence is associated with greater mortality risk than light drinking. In the youth samples, abstainers had a lower risk of dying than those drinking less than 15 times per month. One study of the adult samples showed a significant age by former drinker interaction; this did not alter the lack of association of former drinking with mortality risk or the homogeneity of results across studies for this finding. The most consistent finding was the association of heavy drinking with mortality among youth. Among adults, drinking 43 or more drinks per month and drinking 21 or more times per month were associated with increased mortality risk. Quantity per occasion was not significantly associated with mortality risk among adults. CONCLUSIONS: That frequent drinking was related to mortality risk, whereas heavier quantity was unrelated, is inconsistent with the belief that daily consumption of a few glasses of wine has salutary effects. Empirically, however, this pattern tends to be unusual. Findings were homogeneous across studies lending generalizability to results.

Alcohol consumption and mortality. III. Studies of female populations.

AIMS: This is the third of a set of three papers evaluating drinking status and mortality risk. Analysis of three general population surveys of women evaluated all-cause mortality rates by drinking pattern. DESIGN AND PARTICIPANTS: Raw data from three studies of adult women were evaluated. Logistic regression models controlled for confounding characteristics. Meta-analysis combined study results. MEASUREMENTS: Drinking pattern was alternatively defined by quantity, frequency and volume of drinking. Final models included drinking pattern (including long-term abstainers and former drinkers) as well as age and other confounding variables. Models also evaluated interactions of age and, respectively, long-term abstinence and former drinking. FINDINGS: In models in which age was controlled, odds of death for long-term abstainers and former drinkers (defined by volume or quantity) were greater than those for light drinkers; odds of death for moderate and heavy drinkers (defined by quantity) were greater than those for light drinkers. When other psychosocial attributes were controlled, odds of death were similar for abstainers and light drinkers. When other psychosocial attributes were controlled, odds of death for heavy drinkers (defined by volume and quantity) were greater than those for light drinkers. When interactions of age and the two forms of abstinence were introduced, one study showed a significant effect of age and former drinking. CONCLUSIONS: Results were consistent with the hypothesis that characteristics of abstainers other than their non-use of alcohol may account for their higher mortality risk. With the exception of former drinkers compared to light drinkers, when interactions were introduced into models (for measures of quantity and frequency) findings were homogeneous across studies, lending generalizability to results.

Clinical predictors of transvenous defibrillation energy requirements.

Nonthoracotomy and, more recently, transvenous lead systems have become routine for initial implantable cardioverter-defibrillator (ICD) placement. Previous studies of clinical predictors of nonthoracotomy defibrillation energy requirements evaluated multiple complex lead systems that included subcutaneous patches. However, the predictors of an adequate transvenous defibrillation threshold (DFT) have not been assessed previously. Accordingly, the present study is a prospective evaluation of DFT using a uniform testing protocol in 119 consecutive patients undergoing ICD implantation with a single transvenous lead. For each patient, 38 parameters were assessed including standard clinical, echocardiographic, and radiographic measures. An adequate monophasic DFT (< or =20 J) was achieved in 76% of patients. Multivariable analysis revealed 3 independent factors predictive of a high threshold: preoperative amiodarone use (odds ratio = 5.8, p < or =0.002), echocardiographic measures of left ventricular dilation (odds ratio = 0.47, p < or =0.005) and body size (odds ratio = 0.51, p < or =0.006). Patients receiving amiodarone who also had left ventricular dilation constitute a group at considerable (69%) risk for having a high DFT. In contrast, patients with neither of these risk factors have only an 11% chance of having a high threshold. We conclude that an adequate transvenous DFT can be predicted from simple clinical parameters.

Determinants of life-course variation in the frequency of alcohol consumption: meta-analysis of studies from the collaborative alcohol-related longitudinal project.

OBJECTIVE: This report evaluates the relative contribution of predictors of change in the frequency of alcohol consumption among drinkers, based on the quantitative synthesis of data from 27 longitudinal studies of the general population. The analysis has two objectives: (1) to evaluate the impact of selected demographic characteristics on the magnitude and trajectory of change in drinking across multiple samples, and (2) to assess the influence of methodological characteristics on the consistency of results across studies. METHOD: Raw data from studies including two serial measures of the frequency of alcohol consumption are analyzed. Fixed, random and mixed effects models for meta-analysis are used to pool measures across observations and model the influence of predictors on variability between results. RESULTS: Gender-based variation in the patterning of change is present across all observations, but concentrated in early periods of the life course. Age displays significant predictive effects across all observations, but statistically uniform results are obtained for subjects aged 30 and over. The national origin of study predicts larger amounts of variation than do other demographic predictors in the models. Significant effects are observed for several methodological characteristics of studies. Variation among effect estimates is associated with differences between samples in the interval between first and final measurements, the date of first measurement (a proxy for the historical context of the sample), the percentage retention of subjects between measurements and the time frame of the original alcohol measure. CONCLUSIONS: Based on the synthesis of data from multiple longitudinal samples, this study (1) characterizes normative developmental patterning in the frequency of alcohol consumption and demonstrates the varying effects of demographic factors across the life-course: (2) indicates the key influence of cultural and historical context on the establishment of drinking patterns; and (3) confirms the impact of methodological differences on variation in the results of studies.

Aggregate-level predictors of the prevalence of selected drinking patterns in multiple studies: a research synthesis from the Collaborative Alcohol-Related Longitudinal Project.

This paper examines the prevalence of two "at-risk" alcohol drinking patterns (infrequent heavy drinking and frequent heavy drinking) within age/gender groups in multiple general population studies. When heterogeneity in findings across studies is found, we test the hypotheses that suicide, divorce, unemployment rates, and the per capita consumption of alcohol in each country are associated with the prevalence of these drinking patterns. These analyses should inform the literature on the relationships between societal factors and the prevalence of persons in different societies and periods in history that drink at these levels.

Gender differences for the risk of alcohol-related problems in multiple national contexts.

The primary research question asked is: After holding alcohol consumption constant, will men and women be at equal risk for a variety of alcohol-related problems? Since women are actually at a higher blood alcohol content at the same consumption levels, a physiological argument would suggest that women are at equal or greater risk for alcohol problems than men. However, variation in societal norms surrounding gender roles and/or societal-level stress may mediate the experience of men and women, regardless of the differences in physiology. Ten cross-sectional general population studies are used. Analyses control for individual-level variables (age, quantity, and frequency of drinking) and societal-level variables (proportion of women in the work force and female suicide rate) that might confound these relationships; cross-study homogeneity is examined.

Relationships of measures of alcohol consumption with alcohol-related problems in multiple studies: a research synthesis from the collaborative alcohol-related longitudinal project.

Two measures of alcohol consumption were used to predict groups of alcohol problems in 21 general population studies from 11 countries to determine (a) if quantity of drinking per occasion or frequency of drinking per month constituted significant "risk" for alcohol problems, having controlled for each as well as individual-level and aggregate-level variables which might confound these relationships and (b) if these associations were homogeneous across studies. A two-tiered analysis assessed these relationships within each study by modeling age, sex, quantity per occasion and frequency per month as predictors of alcohol problems. Meta-analysis combined test statistics to determine if they were homogeneous across studies. The meta-analysis was repeated, blocking for per capita consumption of alcohol (a trait of nations thought to measure drinking norms) and the female rate of suicide (a trait of nations thought to measure societal-level stress). When only individual-level variables were controlled (age and sex), both quantity and frequency were risk factors for each drinking problem. However, except in the case of the association of quantity with alcohol treatment, the magnitude of these risks were heterogeneous across studies. When blocking for the societal-level traits, each had more relevance for some, but not all, of the relationships between consumption and problems. Particularly striking was the well-documented finding that per capita consumption of alcohol significantly distinguished the relationships of frequency of drinking and health problems (while the female suicide rate did not) and the previously undocumented finding that the female suicide rate significantly distinguished the relationships of both quantity and frequency with treatment (while the per capita consumption of alcohol did not). These findings suggest that the impact of norms and the impact of societal stress in groups have different but significant consequences for the relationships of consumption to problems.

Societal-level predictors of groups' drinking patterns: a research synthesis from the Collaborative Alcohol-Related Longitudinal Project.

OBJECTIVES: Period effects of per capita consumption of alcohol and divorce rates are assessed for change in quantity and frequency among age/sex groups in multiple longitudinal studies. METHODS: Twenty-five studies of quantity and 29 studies of frequency are used. Studies are from 15 nations and cover periods of 1 to 21 years. Models predict the standardized mean difference for quantity and frequency based on period effects and group-level and methodological variables. RESULTS: When both the period effects of per capita consumption and the divorce rate are considered, the divorce rate significantly predicts change in quantity and frequency. An increase in the divorce rate is associated with a stronger decrease in frequency among younger people; men are more likely than women to decrease their frequency of drinking when divorce rates rise. CONCLUSIONS: Multiple societal-level factors should be considered critical in influencing the drinking patterns of groups. These results suggest that an increase in the divorce rate is associated with more "dry" social contexts, characterized possibly by drinking patterns of a more "volitive" nature (i.e., heavier quantity per occasion and less frequent drinking).

A cross-study contextual analysis of effects from individual-level drinking and group-level drinking factors: a meta-analysis of multiple longitudinal studies from the collaborative alcohol-related longitudinal project.

In contextual (cross-level) analysis within multiple longitudinal general population studies, individual-level drinking behaviors (quantity per typical occasion, frequency of drinking per month and total volume of drinks per month) at final measurement are assessed by three models that simultaneously enter individual- and group-level measures. Two age groups (15-20 and 21-30) are independently assessed. In each model, the Time 1 individual-level drinking behavior and one of three group-level factors are entered. The group-level factors are (1) the percentage of abstainers at Time 1 for each age/sex cohort, (2) the Time 1 group mean for the drinking measure for the age/sex cohort and (3) the mean difference of the age/sex cohort's change in the drinking measure over time. All variables in the model are controlled by variations to exposure in per capita consumption of alcohol during the age/sex cohort's formative years and at Time 2. Meta-analysis assesses the homogeneity of the findings across studies. Models were proposed with the rationale that (1) understanding of individual drinking behavior can be advanced if individual-level data and group-level data are considered in the same models, and (2) integration of these two levels of analyses are, to date, rare. The rationale for using meta-analysis is that findings from the models can be assessed across social contexts with respect to their generalizability. The mean difference model, controlling for individual drinking at Time 1, is the most influential of the group-level models for the younger age group: the degree to which the group changes its drinking pattern is positively related to individual-level drinking behavior at final measurement, over and above the individual's drinking behavior at Time 1, for individual-level frequency of drinking among males (homogeneous among drinkers only). Younger females show more significant relationships for the mean difference females show more significant relationships for the mean difference model. Findings are significant for all relationships examined for the mean difference of the drinking of the group and the individual drinking among the older males and females. Measures of individual-level drinking for all measures at Time 1, controlling for the group-level effects, are significantly related to individual-level drinking at final measurement. The results are homogeneous for quantity (drinkers only) and volume among the young. Findings indicate that characterizations of the drinking for both the individual and the group to which the individual belongs predict measures of drinking practices on the individual level over time.

The influence of health on family contacts and family feelings in advanced old age: a longitudinal study.

This study provides a longitudinal analysis of the influences of health, age, gender, and socioeconomic status on family contacts and family feelings in a sample of 62 members of the Berkeley Older Generation Study. Stability in family contacts and in family feelings was observed over 14 years of advanced old age. Of the four predictor variables, health and socioeconomic status accounted for the largest proportion of observed variance. Contrary to our hypotheses, study participants in better health had greater amounts of contact with family than did those in poorer health. The former also had more feelings of closeness to family members, a finding that may reflect greater possibilities for reciprocity between elders in good health and their family members.

Preliminary results from a meta-analysis of drinking behavior in multiple longitudinal studies.

This paper introduces the scope and rationale of The Collaborative Alcohol-Related Longitudinal Project and describes the individual longitudinal studies which contribute to this large collaborative project, representing studies from 15 countries. It also serves as an introduction to four reports of the preliminary findings from the project. The project is distinguished by (1) its interdisciplinary research approach which has assembled a multidisciplinary group of scholars to direct and interpret analyses, (2) its use of primary data from multiple longitudinal studies, (3) the parallel analyses of primary data from multiple studies, using comparable measures across studies recorded to a standard format and common analytic model, and (4) its use of meta-analysis to combine results across studies. Its research objectives include determining the cross-study consistency of findings of (1) the incidence and chronicity of drinking patterns and problems, (2) exogeneous factors which initiate and alter drinking careers, (3) socio-behavioral factors measured in childhood and adolescence which predict adult drinking problems, (4) inter-generational biological and social factors which predict adult drinking problems, and (5) aggregate-level factors which account for study differences. The method of sampling of studies from the world's alcohol-related general population longitudinal research is described.

A meta-analysis of life course variation in drinking.

Meta-analysis combines results from multiple longitudinal studies to describe life course variation by age and sex for quantity of drinking per typical occasion (20 studies) and frequency of drinking during one month (27 studies). There is cross-study heterogeneity for the Time 1 means of the drinking variables blocking for age and sex. Age distributions for the Time 1 means are similar by gender within nations; in the aggregate, males exceed females in the magnitude of drinking. Dramatic shifts in the standardized mean difference (M2-M1) occur among the young; greater homogeneity and moderate change (declines) occur later in life. Implicated in improving cross-study homogeneity for M2-M1 among the young are interval between measurements, nation, Time 1 per capita consumption (PCC), difference in PCC and the Time 1 mean. Lower unstandardized regression coefficients are found for quantity among youth, but are not consistently homogeneous within nations; the association for frequency becomes increasingly stable with increasing age. Nation and interval are implicated in improving homogeneity. Decline in quantity occurs among the old. M2-M1 produces homogeneously higher regressions for groups of the young who increase quantity v. those who do not. Linkage of the group-level and individual-level findings is discussed.

A meta-analysis of change in marital and employment status as predictors of alcohol consumption on a typical occasion.

Meta-analysis is used to combine results of primary data from 12 longitudinal studies to examine the consistency of results with respect to the role of changes on the individual level in marital status and employment status on changes in consumption of alcohol per typical occasion. The analyses control for the effects of Time 1 consumption per occasion and education. Not getting married and becoming unmarried are associated with increased consumption at follow-up and both variables are positively related to increased consumption among older men, but only becoming unmarried was related to increased consumption among older women. Becoming married is homogeneously and negatively associated with consumption at follow-up for younger and older persons of both sexes. Chronic unemployment is negatively related to consumption at follow-up among older males and younger females. Becoming unemployed between measurements is homogeneously and negatively related to consumption among older males and females, but positively related among younger males. Becoming employed is homogeneously and positively related to later consumption among all groups except young females.

A meta-analysis of depressive symptomatology and alcohol consumption over time.

Meta-analysis (eight general population longitudinal studies) describes the relationships (regressions) between quantity per occasion and depressive symptomatology over time. Quantity and depression are the strongest and most consistent predictors of final levels of themselves in all data sets. Age significantly and consistently predicts quantity for both sexes combined (the general pattern is replicated among males only). Depression significantly predicts quantity and quantity significantly predicts depression for females. Controlling for interval between measurements produces stronger prediction (more consistent over shorter intervals) for males. Depression only predicts quantity over longer intervals and quantity only predicts depression over shorter intervals for females. Explicit control for age found stronger relationships between initial and final measurement quantity, and depression for males. Quantity and depression significantly predict quantity and depression among young females. The relationship between quantity and depression among females illustrates the importance of controlling for age and sex. Methodological considerations are discussed.

An integrated approach to meta-analysis in alcohol studies.

The research design and methods utilized by the Collaborative Alcohol-Related Longitudinal Project are described. The project design addresses the critical need to develop procedures to assess the replicability of research results in alcohol studies. Key features of the research plan include: re-analysis of original data from multiple longitudinal studies of drinking behavior in the general population; centralization of all data analyses, developed and implemented by an interdisciplinary core staff; development of the research plan and interpretation of results in co-operation with original investigators of studies included in the project; and use of modeling procedures from meta-analysis to quantify the relative contribution of factors influencing the distribution of effect estimates across studies, including both methodological differences and aggregate level variables. The final section describes statistical methods for meta-analysis used by the project, including procedures for the calculation and combination of estimates of effect magnitude, categorical and continuous modeling procedures for use with effect sizes, and random effects models.

Long-term outcomes of drinking: a 20-year longitudinal study of men.

This paper examines long-term changes in drinking, with regard to: (a) the degree to which overall patterns of drinking have shifted or remained across a 20-year period; (b) whether these patterns vary on the basis of age; and (c) the degree to which distinct patterns of drinking may be differentially subject to mortality and/or nonresponse. Data for this investigation are from a 20-year prospective follow-up study of two general population surveys. The first of these was originally interviewed in 1964 and consists of interviews with 405 males aged 23 and older; the second, originally interviewed in 1967, consists of interviews with 786 males aged 21-59. The results indicate that while consumption was modestly associated with mortality from all causes, no significant relationship was observed between consumption and non-response. The results also indicate that as respondents aged 20 years, mean levels of alcohol consumption remained stable. This was true despite the fact that when individual respondents did change their drinking, they were more likely to decrease their consumption than increase it. These results do not support conclusion drawn from cross-sectional studies that aging modifies consumption patterns.

Continuity in intellectual functioning: the role of self-reported health.

Surviving members of the Berkeley Older Generation Study were interviewed and tested with the Wechsler Adult Intelligence Scale in 1969-1970 and again in 1983-1984, when subjects' ages ranged from 73 to 93. Health was assessed by self-reports at both measurement periods. Although many individuals showed some decline in intellectual functioning, substantial individual differences were apparent at all age levels. More than one half of the subjects showed no reliable change, and a minority showed a reliable increase in verbal scores. The role of self-reported health has increasing importance in the maintenance of intellectual functioning in advanced old age.

Cigarette smoking motives: factorial structure and gender differences in a longitudinal study.

Research investigating the factorial structure of cigarette smoking motives (based on the Horn-Waingrow Smoking Survey) suggests considerable similarity in factor structure across different samples as well as stability of structure in repeated assessments. This study evaluates the replicability of six commonly found Horn-Waingrow factors in a sample of 109 men and women from three longitudinal studies and also reports on gender and other psychosocial differences. Principal component analyses exactly replicated previously reported factors, separately for each gender. Significant gender differences in level are shown for two smoking motives (Reduction of Negative Affect and Pleasure): Women more than men report that they smoke for these reasons. Also, there are significant differences in motives between current and former smokers and between smokers with and without smoking spouses.