Smoking as a risk factor for developing Multiple Sclerosis: A meta-analysis of observational studies.

OBJECTIVE: The aim of this study was to improve and update the pool of available studies included in the previous meta-analyses, and to provide further evidence about smoking as a risk factor for MS. MATERIAL AND METHODS: PubMed and Scopus searches were undertaken to identify studies investigating the association between cigarette smoking and MS. Odds ratio (OR), relative risk (RR) together with 95% confidence intervals (CIs) were calculated for case-control and cohort studies and prevalence rate for cross sectional. RESULTS: 33 studies were suitable for the meta-analysis. The summary OR for case control studies (ever versus never) was 1.40 (95% CI, 1.29 to 1.52) and 1.42 (1.26-1.60) for current vs. no-smokers. CONCLUSIONS: Smoking is associated with MS risk. Research using animal models can help to fully understand the mechanisms behind the association.

Alcohol intake and cardiovascular disease and mortality: the role of pre-existing disease.

OBJECTIVES: Pre-existing conditions have been postulated as possible causes of the J-shaped relationship between alcohol intake and cardiovascular disease. Two research questions have been addressed in this paper. First, whether never drinkers and former drinkers differ from moderate drinkers in terms of health, and if so, which health problems contribute to this difference. Second, whether the U-shaped relationship between current alcohol intake and cardiovascular disease or all-cause mortality could in part be explained by difference in pre-existing disease burden. DESIGN, SETTING AND PARTICIPANTS: A prospective case-cohort, the Lifestyle and Health Study, consisting of 16,210 men and women aged between 45 and 70 years. Alcohol intake and risk factors were assessed at baseline with a self-administered questionnaire. Medical information was obtained from general practitioners. Cardiovascular events and mortality were followed for a period of 5 years (1996-2001). MAIN RESULTS: Never drinkers and former drinkers were less healthy than moderate drinkers. They rated their health more often as poor, and often had more diseases, such as cardiovascular disease, diabetes, and also alcohol-related diseases. The difference in disease burden did not change the observed relationship between alcohol intake and cardiovascular events, and only partially changed the U-shaped relationship between alcohol intake and all-cause mortality. CONCLUSIONS: The found difference in health between never drinkers and former drinkers compared with moderate drinkers appeared to be only a partial explanation of the observed relationships between alcohol intake and cardiovascular disease, and between alcohol intake and all-cause mortality.

Lower prevalence of heart disease but higher mortality risk during follow-up was found among nonrespondents to a cohort study.

OBJECTIVE: The primary aim was to assess the association between response behavior and health status at baseline, and survival in a 5-year follow-up period. A secondary aim was to assess whether reasons for nonresponse were associated with health status at baseline. STUDY DESIGN AND SETTING: Data came from a prospective study cohort consisting of 31,349 men and women aged 45-70 years. Objective retrospective and prospective health information derived from general practitioner registries was available for both respondents and nonrespondents. RESULTS: Results show that among respondents coronary heart disease was more prevalent. Compared with respondents, noncontacts had a higher mortality risk during follow-up. Refusals had hypercholesterolemia more often than did noncontacts, and coronary heart disease or diabetes mellitus less often. CONCLUSION: The paradoxical results that respondents are less healthy at baseline but prospectively have a lower mortality risk may point to a selection effect indicating that the 'worried ill' are more inclined to participate. This effect could imply that observed relationships between risk factors or behaviors and outcomes in cohort studies may be attenuated.

Measurement of lifetime alcohol intake: utility of a self-administered questionnaire.

Prior epidemiologic research revealing cardioprotective effects of alcohol intake has systematically neglected lifetime exposure to alcohol, which may cause serious bias in conclusions regarding drinking and heart disease risk. Departing from use of an earlier interview schedule, the authors of the present 1996-2001 cohort study developed a self-administered Lifetime Drinking History questionnaire (LDH-q). A total of 16,211 Dutch men and women older than age 45 years participated by completing the baseline questionnaire. A random sample of 3,255 men and women was used to determine the reliability and validity of the LDH-q. Test-retest reliability was assessed by means of the intraclass correlation coefficient and kappa scores. Correlations between lifetime and current intake scores were used to assess discriminant and convergent validity. Both reliability and validity appeared to be reasonably high compared with results obtained by using interview formats to measure lifetime alcohol intake. Reliability of the LDH-q was higher for men than for women, probably because of the more frequent and regular drinking of men. Indices of validity were similar for men (0.75) and women (0.70). Results show that the LDH-q can be a useful instrument in large-scale cohort studies.

Older and younger male alcoholics in outpatient treatment.

In the coming decades, the proportion of the older age groups in the total population, and, therefore, in the alcoholic population, will be increasing. The aim of the study is to assess to what extent older alcoholics form a distinct group within the problem-drinking population. Alcoholics in outpatient treatment of over 50 years of age (n = 52) are compared with those from the modal age group (ages 35-44, n = 55). Results indicate that problems with alcohol are less severe among older alcoholics. Contrary to expectation, older alcoholics did not report more health problems. No differences were observed in the duration of the treatment career. It is concluded that older alcoholics show the same types of problems, but less so than younger alcoholics. Further research is indicated regarding late onset, older alcoholics with multiple diagnosis, and drinking problems in the age group over 70.

Coverage of beverage alcohol issues in the print media in the United States, 1985-1991.

OBJECTIVES: This study assessed the portrayal of alcohol-related issues in the print media in the United States during the 7-year period bracketing implementation of the US alcohol warning label act in November 1988. METHODS: All articles that appeared from 1985 to 1991 in 5 national newspapers and that were indexed as dealing with beverage alcohol were identified. Content analysis of a 15% sample of these articles allowed an in-depth assessment of the conceptualization of alcohol in the US print media. RESULTS: A slight decrease in articles related to alcoholism was offset by an increase in articles about the more general health-related effects of alcohol. The warning label act received little attention. Most articles portrayed alcohol neutrally or negatively, using information from government sources. CONCLUSIONS: Portrayal of alcohol in the US print media has changed in recent decades. A general shift noted as early as the 1960s has increasingly emphasized public health issues and deemphasized clinical aspects of alcoholism. This has been accompanied by a continuing shift away from a biopsychological definition of alcohol-related behavior to a definition stressing external environmental factors.

Buying research.

Doubts have been raised in the popular press about the credibility and desirability of alcohol research funded by the industry. In this paper, it is asserted that little independent, empirical research is available on the effects commercial sponsorship has on the research topic and outcome. The author proposes further research in this area that would be helpful in clearing the menaces of unwanted funding practices. It is suggested to draw up guidelines or rules of conduct similar to those that are being developed in, particularly, pharmacological research, an area that is highly dependent upon sponsorship by commercial industry.

Gender differences in alcohol use and alcohol problems: mediation by social roles and gender-role attitudes.

This study assesses the causal place of Traditional Gender Role Attitudes (TGRA) in models for men and women, which also include social roles by explanatory variables for alcohol use and alcohol problems. Mediation of gender differences by TGRA occurs mainly in abstinence. Interaction effect is weak for alcohol consumption and frequency of "heavy drinking." The most important explanatory variables are the status factors age and education, which are mediated by TGRA in a small way. Specific aspects of alcohol-related problems are analyzed separately for the problem drinking category. Differences in results with other studies are discussed, and further study is proposed.

Drinking careers of older male alcoholics in treatment as compared to younger alcoholics and to older social drinkers.

OBJECTIVE: In order to answer the question whether older alcoholics form a distinct group among problem drinkers and within their age cohort, drinking histories of male, older (over 50 years of age) alcoholics in treatment (n = 52) are compared to those of younger alcoholics (n = 55), and to those of older social drinkers (n = 46). Within the older alcoholics category, comparisons are made by age of onset. Changes in consumption volume and onset and remission of heavy drinking, morning drinking and solitary drinking are related to events in other spheres of life. METHOD: In face-to-face interviews, respondents were asked to report drinking behavior in subsequent drinking phases, from the beginning of regular drinking to the present. Events that marked a transition to a new drinking phase, as well as the impact that these events had on the general well-being of the respondents, were assessed using a semistructured interview format. RESULTS: Compared to younger alcoholics, older alcoholics were older when they started drinking regularly, and they report later age at onset of heavy drinking. Older alcoholics and social drinkers were similar with respect to the first years of their drinking career. Older alcoholics with onset of heavy drinking before the age of 35 were similar to younger alcoholics, while older alcoholics with later onset of heavy drinking resembled social drinkers with respect to their earlier drinking history. Alcoholics with later onset more often reported onset in connection with events such as marital disruption. CONCLUSION: Among older alcoholics, a distinct group can be distinguished that may benefit from specific prevention and treatment measures.

Gender differences in drinking behaviour in the Netherlands: convergence or stability?

Gender differences in drinking behavior are analysed with emphasis on their relationship with changes in roles and positions of men and women in society. The 'convergence hypothesis' is used as a starting point. From its implications, a number of specific hypotheses are derived and tested using data from six surveys of the general population of the Netherlands, held between 1958 and 1993. No convergence of gender differences is found for abstinence and heavy frequent drinking. Convergence of male-female differences in average weekly consumption appeared in the 1980s, but it is no longer significant at 5% level after controlling for age, education and family situation. Further elaboration of the gender by year interaction shows that convergence is related to a decrease in consumption among higher educated men. Contrary to expectation, an increase in consumption has occurred among women over 40 years of age. No relationship appears with female employment and religion. Having a family is related to lower consumption among women, while it has no significant effect on men's consumption. Although some evidence for convergence was found, results are not in agreement with expectations formulated from the perspective of the convergence hypothesis.

The alcohol content of self-report and 'standard' drinks.

A stubborn problem in alcohol epidemiology is that of standardization of unit of measurement. Consistent use of the 'standard drink' in research reports is hampered by difficulties in the assessment of the alcohol content of, particularly, self-reported drinks. Alcohol content of a drink depends on strength of the beverage and volume of the glass or container from which the beverage is taken. Both factors vary considerably between times, regions and individuals. Interview protocols and questionnaires rarely take into account the fact that people consume alcoholic beverages from a large variety of glasses and containers. In the present study the common presumption is tested of equality of alcohol content of standard and self-reported drinks. The test consisted of measuring the amount of wine, fortified wine and spirits people usually pour in the glass typical for the beverage type. The sample was drawn from the general Dutch population in 1985. The results show that on average self-reported drinks taken at home contained more than the presumed standard (10 g per drink). The deviation was highest for spirits (+26%), followed by fortified wines (+14%) and least for wine (+4%). There seemed to be a positive relationship between deviation from 'standard' and strength of the alcoholic beverage. This result is in line with data on the coverage of sales data: aggregate, survey-based spirits consumption shows the lowest coverage of sales. The effect of the difference between actual and presumed content of drinks on estimates of consumption is an overall increase of 7.5%, higher for women (+12%) than for men (+6%). Results are discussed with respect to the use of the concept of 'standard unit' in research protocols and health education campaigns.

Seasonal variation in survey and sales estimates of alcohol consumption.

Time variation of drinking is substantial and has an effect on aggregate estimates of consumption. In this article it is shown that because of a considerable seasonal variation in consumption (+/- 20%) a serious bias in annual consumption estimates can be expected in surveys with a limited time frame. The present study analyzes drinking data collected in the general population of the Netherlands from March 1985 through December 1985 (including Christmas and New Year's Eve). Since it was expected that sensitivity to temporal fluctuations might not be equal for different methods of measurement, several indices of consumption were compared. Although the assessed seasonal effect varies indeed across types of measurement, across male and female subsample and across types of alcoholic beverage, the general tendency is for consumption to be highest in the spring season and lowest in the autumn. Sales figures fluctuate accordingly. It is evident that the risk of biased estimates is larger the shorter the time frame of the survey. Seasonal variation was highest in the frequency domain. Furthermore, exclusion from the time frame of collective holidays, during which people drink more often and more per occasion (viz., Christmas), increases the risk of biased estimates. Even estimates of abstention, but also regular heavy drinking among women, appear to vary considerably over the three seasons in this study. The main conclusion is that results of comparisons of survey data on drinking, particularly those over time, are more or less invalid if the respective time frames of the surveys do not correspond.

Regularity in alcohol distributions: implications for the collective nature of drinking behaviour.

The assumption of a one parameter lognormal distribution in the Ledermann theory is relaxed. Implications of only regularity in distributional form for the collective nature of drinking behaviour are considered. It is shown that there must be a so-called point of attraction over which an increase in mean consumption will result in a decrease of percentile point value. The validity of regularity in distributional form and the practical relevance of the Ledermann model is discussed. An example from Dutch data on alcohol consumption among men obtained in 1970 and 1985 illustrates the relevance of an existing point of attraction.

Comparing distributions of alcohol consumption: empirical probability plots.

Parametric approaches to the problem of the distribution of alcohol consumption have not been very successful. In this article, it is shown that regulatory in distribution can be studied without making assumptions about a distribution model underlying the data. For this purpose, a method is used with which distributions are compared graphically in so-called probability plots. It appears that, up to a proper linear transformation on a logarithmic scale, a surprisingly large regularity over time can be observed between distributions taken from Dutch samples in 1970, 1981 and 1985. Equally, distributions from male and female sub-samples do not appear to differ up to a linear shift. The finding of a relative equality in distributional form is in accordance with the Ledermann model. However, the difference with the Ledermann's model is that no assumptions about the exact shape of the distributions are being made.