Missed epidemics and missing links: international birth cohort trends in multiple sclerosis.

BACKGROUND AND PURPOSE: Many hypotheses on the etiopathogenesis of multiple sclerosis (MS) focus on risk factors occurring early in life. This study examined the variability of birth cohort trends in international MS data by means of age-period-cohort (APC) analysis. METHODS: The data from 25 countries were taken from the WHO mortality database. Data were encoded according to the International Classification of Diseases and covered slightly varying periods between 1951 and 2009. The APC analyses were based on logit models applied to cohort tables with 5-year age- and period intervals. RESULTS: In most countries, the birth cohort estimates peaked in those born in the first half of the 20th century. In countries from Central and Western Europe, the peak concerned those born before and around 1920. A second group of countries (Denmark, Sweden, Italy, Ireland, Scotland) shared a later peak amongst cohorts born in the 1920s and 1930s. Group 3 included Commonwealth countries, the USA and Norway, with a double or extended peak starting in the 1910s or 1920s, and ending by the 1950s. The fourth group, consisting of Mediterranean countries and Finland, was characterized by a steady increase in the birth cohort estimates until the 1950s. The fifth group with countries from Eastern Europe and Japan showed no particular pattern. CONCLUSIONS: Birth cohort trends have influenced the change in MS risk across the 20th century in many Western countries. This silent epidemic points to a most important but unknown latent risk factor in MS.

Causation of injuries in female football players in top-level tournaments.

BACKGROUND: Analyses of tackle parameters in injury situations have provided valuable information regarding men's football. However, there are no similar data for women's football. OBJECTIVE: To categorise the tackle mechanisms leading to injury in elite women's football. STUDY DESIGN: Retrospective video analysis of injury situations. METHODS: Events associated with all reported injuries during six women's top-level tournaments were analysed on video recordings for tackle parameters. RESULTS: More than half of all injuries were due to tackles from the side (52%, 103/200), whereas tackles from behind were much less commonly involved in injury situations (11%, 21/200). One-footed (65%, 130/200) and upper body (21%, 42/200) tackle actions were most common. Sliding-in tackles leading to injury were the least likely to be sanctioned by match referees. Tackling players (45%, 90/200) were almost as likely to be injured as the tackled player (55%). CONCLUSION: The present study found differences between injury mechanisms in women's football and previously published data on men's football. Further research, especially using video analysis, is needed for a better understanding of risk situations in football.

Accuracy of the Michigan Alcoholism Screening Test for screening of alcoholism in patients of a medical department.

To measure the applicability and validity of the Michigan Alcoholism Screening Test in a medical hospital department situated in the French-speaking part of Switzerland, the test was administered to 300 patients. The results of the test were validated in relation to the clinical diagnosis of alcohol abuse or alcoholism through a concordance analysis. The applicability rate was 89% and the agreement between test and clinical diagnosis was good, especially in young men. Positive and negative predictive values of the test were 0.69 and 0.92, respectively. These results suggest, therefore, that the Michigan Alcoholism Screening Test could be considered as a standardized, valuable, and transcultural screening and research instrument.

Association of low plasma cholesterol with mortality for cancer at various sites in men: 17-y follow-up of the prospective Basel study.

BACKGROUND: Low serum cholesterol has been associated with an increased risk of cancer mortality in various studies, which has led to uncertainty regarding the benefit of lower blood cholesterol. OBJECTIVE: The aim of our study was to evaluate the association between low blood cholesterol (<5.16 mmol/L) and cancer at sites that have rarely been evaluated. We placed special emphasis on the potential confounding effect of antioxidant vitamins. DESIGN: Plasma concentrations of cholesterol and antioxidant vitamins were measured in 1971-1973 in 2974 men working in Basel, Switzerland. In 1990, the vital status of all participants was assessed. RESULTS: Two hundred ninety of the participants had died from cancer, 87 from lung, 30 from prostate, 28 from stomach, and 22 from colon cancer. Group means for plasma cholesterol concentrations did not differ significantly between survivors and those who died from cancer at any of the studied sites. With plasma cholesterol, vitamins C and E, retinol, carotene, smoking, and age accounted for in a Cox model, an increase in total cancer mortality in lung, prostate, and colon but not in stomach cancer mortality was observed in men >60 y of age with low plasma cholesterol. When data from the first 2 y of follow-up were excluded from the analysis, the relative risk estimates remained practically unchanged with regard to lung cancer but decreased for colon, prostate, and overall cancer. CONCLUSIONS: Increased cancer mortality risks associated with low plasma cholesterol were not explained by the confounding effect of antioxidant vitamins, but were attributed in part to the effect of preexisting cancer.

Effects of long-term, self-monitored exercise on the serum lipoprotein and apolipoprotein profile in middle-aged men.

To study the effects of long-term, self-monitored exercise on the serum lipid profile and body composition of middle-aged non-smoking males, a controlled study was conducted in 61 sedentary, middle-class Swiss men. Thirty-nine men were randomly allocated to jog 2 h/wk for 4 months on an individually prescribed, heart rate-controlled basis, whereas 22 men served as controls. Despite varying adherence to the exercise regimen, the following 4-month net changes (effect in exercise group minus effect in control group) in lipids were seen: HDL cholesterol (C) +0.12 mmol/l (95% CI 0.02, 0.22; P = 0.028), LDL-C +0.08 mmol/l (ns), VLDL-C -0.26 mmol/l (-0.45, -0.07; P = 0.009), total triglycerides (TT) -0.21 mmol/l (ns), HDL-C/total C +0.02 (0.001, 0.05; P = 0.047). The net changes in endurance capacity and resting heart rate in favour of exercisers were significant as well, whereas no significant changes in apolipoprotein levels were seen. Exploratory analyses revealed, for example, associations of the increase in total physical activity with an increase in the HDL-C/total C ratio (r = 0.46; P less than 0.001), and of the change in estimated body fat content with an opposed change in the HDL-C/total C ratio (r = -0.40; P less than 0.001), or an inverse relationship of the change in subcutaneous fat with a change in the HDL2-C level (r = -0.39; P less than 0.001). Multivariable regression analysis suggested that much of the effect of jogging on HDL-C was apparently mediated through a decrease in body fat content. A change in the waist/hip ratio was unrelated to lipoprotein changes but was related to the change of TT level (r = 0.22; P less than 0.05). This study confirms that individually prescribed, unsupervised jogging can increase HDL-C levels and improve the serum lipoprotein profile in self-selected nonsmoking males. Although the effect is modest, it may be relevant to preventive cardiology, given the evidence for a reduction in cardiovascular risk even after apparently small decreases in risk factor levels.

Jogging or walking--comparison of health effects.

The present study compared the different health effects of 6 months' endurance training at two exercise intensities. Seventy-five nonsmoking, sedentary men were randomly assigned to either a home-based, unsupervised exercise program of 4 x 30 min/wk jogging at an intensity of 75% VO2max (n = 28), or of 6 x 30 min/wk walking at an intensity of 50% VO2max (n = 28), or to an inactive control group (n = 19). Exercise adherence and injuries related to exercise training as well as changes in endurance capacity, body fat, and serum lipids were assessed. After 6 months, joggers and walkers showed a similar increase in VO2max as measured by a maximal bicycle ergometer test (2.9 +/- 4.1 ml/kg min, P < 0.01 and 2.5 +/- 5.7 ml/kg min, P < 0.5, respectively). There were no significant changes in blood lipids in either group, although results revealed a significant association between the amount of training (i.e., kilometers exercised) and the increase in high-density lipoprotein-cholesterol (HDL-C) in joggers (Pearson's r = 0.42, P < 0.05). In walkers, a significant association between the amount of exercise and the decrease in sum of skinfolds and the waist-hip ratio was observed (Pearson's r = -0.48 and -0.45, P < 0.05 for both). The adherence rate was similar for both training groups with respect to the prescribed intervention goal with an average of 90 +/- 41 min/wk (joggers) and 121 +/- 72 min/wk (walkers) spent on endurance training.(ABSTRACT TRUNCATED AT 250 WORDS)

Safer sex behavior and alcohol consumption. Research Group of the Swiss HIV Prevention Study.

To test the hypothesis that safer sex procedures are less consistently observed by persons under the influence of alcohol, data from the Swiss human immunodeficiency virus (HIV) Prevention Study (HIPS) were evaluated. HIPS is a large prospective cohort study involving 724 HIV-negative and mainly heterosexual subjects who entertain casual sexual contacts. Of the 724 participants, 36% reported that they had had sex while under the influence of alcohol. Of this group, 31% indicated that safer sex procedures were neglected owing to the influence of alcohol. No significant differences with regard to unprotected sexual intercourse were found between subjects who combine sex and alcohol and those who do not. The same was found to be true among subjects with different levels of general alcohol consumption. However, a significant correlation was found between the intensity of alcohol consumption (i.e., the quantity of alcohol intake per sitting) and the incidence of unprotected sexual intercourse. These findings show that the relationship between alcohol consumption and safer sex is complex; they also emphasize the need for preventive efforts to reinforce safer sexual behavior, for example through individual counseling of persons at risk for HIV-infection.

A meta-analysis of acupuncture for chronic pain.

Results of 14 randomized controlled trials of acupuncture for chronic pain were pooled in a meta-analysis and analysed in three subgroups according to site of pain; and in two subgroups each according to type to trial, type of treatment, type of control, 'blindness' of participating agents, trial size, and type of journal in which results were published. While few individual trials had statistically significant results, pooled results of many subgroups attained statistical significance in favour of acupuncture. Various potential sources of bias, including problems with blindness, precluded a conclusive finding although most results apparently favoured acupuncture.

Dietary nitrates, nitrites, and N-nitroso compounds and cancer risk: a review of the epidemiologic evidence.

Experimental animal studies have shown N-nitroso compounds (NOC) to be potent carcinogens. Epidemiologic evidence of the carcinogenic potential of dietary NOC and precursor nitrates and nitrites in humans remains inconclusive with regard to the risk of stomach, brain, esophageal, and nasopharyngeal cancers. Inadequate available data could obscure a small to moderate effect of NOC.

Early morning melatonin administration impairs psychomotor vigilance.

The acute soporific effect of melatonin in humans has been demonstrated in a range of studies. How alertness and performance are changed after melatonin given in the morning is not yet known. In a double-blind, placebo-controlled study of nine healthy young men, melatonin was given at 0700 h under controlled conditions of a modified constant routine protocol lasting 56 h (2 days, 3 nights with sleep). A clear decrement in neurobehavioral functions as measured by the Psychomotor Vigilance Test lasted for 6 h after melatonin administration (particularly in the lapse domain and median of the reaction time) without any effect on a letter cancellation task. A subjective soporific effect was present but less pronounced. Thus, melatonin taken in the morning requires caution in situations where high attention is needed.

Incidence of invasive cervical cancer in the Swiss canton of Vaud, and a note on screening.

Age adjusted incidence rates (World standard) from invasive cervical cancer in the Swiss canton of Vaud decreased from 17.7/100,000 in 1968-70 to 9.9/100,000 in 1983-85. The decline was substantial in younger middle age, but no appreciable trend was observed in women over 70. This is consistent with available interview based information on the pattern of cervical screening in the Swiss population. Although there was no organised screening programme in Switzerland, over 80% of women aged 20-44 and 65% of those aged 45-64 reported one or more screening smears over the previous 3 years, compared to only 22% of women aged 65 or over. In the last calendar period, there was an apparent increase in the incidence of invasive cervical cancer (from 2.5 to 6.1/100,000) in women aged 25-29. Although based on small absolute numbers, this is in agreement with incidence and mortality data from other countries, and may therefore confirm a change in risk factor exposure in younger women.

Social class gradients in years of potential life lost in Switzerland.

Analysis of the official Swiss mortality data have shown considerable social differences. In an earlier study of Swiss men aged 15-74 for the period 1979-1982 the social class mortality differentials have been analysed using standardized mortality ratios (SMR). The present study extends this previous work by calculating years of potential life lost (YPLL) before age 75, an additional indicator of mortality that puts more importance on deaths at younger ages. Emphasis is given on causes contributing to most years of life lost, especially to accidents and violent deaths, which result in more than 30% of total years of life lost. The distribution of years of life lost of the most important causes to social classes is illustrated also for age-specific groups. Additionally, this article presents all causes which account for more than 3% of total years of life lost. The social inequalities are shown as ratios between the social class with the highest (skilled manual workers) and the lowest risk (professionals). Most years of life are lost by skilled manual workers not only in general but also cause-specific. While the SMR from all causes of death showed a 2-fold difference between professionals and skilled manual workers, the social gradient in YPLL rate was even larger (2.5). Hence, the measure of years of potential life lost emphasizes the disadvantage of skilled manual workers to die earlier than professionals. The concept of YPLL proved to be a useful additional indicator not only of mortality in general, but also especially for monitoring causes, related to the lower social classes.

Coronary arteriography rates in Switzerland--how do they vary?

Coronary heart disease is a leading cause of death for both sexes in developed countries. Controversy has arisen about the health benefits and risks of coronary surgery and, more recently of coronary angioplasty. As a clinical prerequisite to these interventions, coronary arteriography can be considered an indicator of invasive services offered to coronary heart disease patients. We collected data on characteristics of all patients subjected to coronary arteriography during 1984 in Switzerland. A total of 4921 coronary arteriographies were performed among 4359 patients; this corresponds to 77 procedures/100,000 residents and 68 patients/100,000 residents. Rates for men are 4.2 times women's rates, and the highest utilization rate for both sexes are observed in the group aged 40-64. Large variations characterize cantonal and regional coronary arteriography rates. Similarly, the distribution of centers practising this procedure is not uniform. These observations are placed in the context of the general practice of coronary angiography, changes expected in the face of by-pass surgery and angioplasty expansion, and coronary heart disease data.

Psychoactive drug use among medical doctors is higher than in the general population.

We surveyed a representative sample of practising physicians and a representative sample of subjects from the Swiss general population (SOMIPOPS Survey) concerning their annual use of sleeping pills and tranquillizers. 77% of the physicians (n = 466) and 72% of the general population (n = 4255) responded. After adjustment for age and sex 37.1% of the doctors (general population 21.1% P less than 0.001) claimed to have taken these drugs for therapeutic purposes. The proportion of psychiatrists who reported taking sleeping pills and tranquillizers daily (10.6%) were significantly greater than for the population of doctors as a whole and for the general population (P less than 0.05). Regular users (i.e. subjects taking one mood altering drug at least once a week) accounted for 11.1% of the medical population compared with 6.8% of the general population (P less than 0.01). This over-consumption was wholly due to the greater number of regular users of psychoactive drugs amongst doctors less than 50 years of age relative to the general population or to subjects in higher management (from P less than 0.05 to P less than 0.001). Without this specific over-use, members of the medical profession would not have been found to use more psychoactive drugs than the general population and the executives. This result suggests that it would be worth investigating the mechanisms of response and adjustment (coping) to the specific stress that appears to be inherent in the exercise of medical practice.

One-year prevalence of low back pain in two Swiss regions: estimates from the population participating in the 1992-1993 MONICA project.

STUDY DESIGN: A cross-sectional survey was performed. OBJECTIVE: To estimate the extent of low back pain as a public health problem. SUMMARY OF BACKGROUND DATA: Health surveys converge on very high estimates of low back pain in general populations, but few studies have included severity criteria in their definition and conclusions. Because it is unlikely that interventions will influence the prevalence of minimal and infrequent symptoms, greater attention should be paid to characteristics of low back pain that indicate some impact on the life of survey respondents. METHODS: Two regions participated in the MONICA (MONitoring of trends and determinants in CArdiovascular disease) project in Switzerland. Participants randomly selected from the general population completed a standard self-administered questionnaire on cardiovascular risk factors. A special section on low back pain was added in the third (1992-1993) MONICA survey and completed by 3227 participants. RESULTS: A regional difference found in the 12-month prevalence rate disappeared with the inclusion of severity criteria. Low back pain over more than seven cumulated days was reported among men by 20.2% (age range, 25-34 years) to 28.5% (age range, 65-74 years), respectively, among women by 31.1% to 38.5%. Similar rates of reduction in activity (professional, housekeeping, and leisure time) and medical consultation (conventional and nonconventional) motivated by low back pain characterized the two participating regions. The cumulative duration of pain was related to all the indicators showing the impact of low back pain on everyday life. CONCLUSIONS: Determining the cumulative duration of low back pain over the preceding year is a straightforward task, and a cutoff at 1 week seems appropriate for distinguishing between low- and high-impact low back pain.

Quality assessment in gynecology and obstetrics. Projects and experience in Switzerland.

The first steps in quality assessment of results of performance in gynecology and obstetrics were taken by the Swiss Association of the OB/GYN Clinics of the Swiss Society of Obstetrics and Gynecology in the 1980's. Currently, medical data of more than 800,000 patients are available, allowing a good comparison of the quality of results. Concerned that purchasing coverage for health services was made exclusively on the basis of cost, resulting in lower public health quality, the Swiss Society of OB/GYN set up a Board of Quality Assessment in 1995. Not only the quality of results, but also the quality of indications, structures and processes are considered by using a modified Donabedian model. Moreover, standardized patient information forms have been worked out for 15 gynecological and five obstetrical operations. Since hysterectomy is the most common major gynecological operation in Switzerland, the evaluation of the quality of the indications is of substantial interest. Guided by the RAND Appropriateness Method, criteria for quality assessment with respect to appropriateness and necessity of hysterectomy have been drawn up. Swiss guidelines and 125 different clinical scenarios are defined by a panel of 22 OB/GYN experts. The aim of this project is to offer an interactive second opinion system, called "Swiss Guidelines for Hysterectomy", and anonymous self-assessment of quality. Appropriateness and necessity of medical procedures have to be defined by medical professionals providing a proper balance between the patient's desires and financial demands.

The assessment of medical technologist. Examples from Switzerland.

The need for assessment of new medical technologies has recently become evident in many countries, especially for the people responsible for health care policy. There are multiple reasons for making evaluation: rising costs in health care, medical efficacy, safety, as well as social and political issues. Each stage of life of a diagnostic, therapeutic or preventive technology, from its emergence to obsolescence, can be assessed by an appropriate procedure. In Switzerland, a country with decentralized health care as well as political systems, the assessment is made by various institutions. Evaluative aspects are included in some National Research Foundation programs. Most work, however, is done by the division of medical techniques at the Swiss Hospital Institute. The panel of experts has recently prepared a report on magnetic resonance imaging (MRI). As a result of the initial evaluation, the need for this new technology in this country, and the number and sites of MRI systems for the next few years were established. The capital, running and unitary costs of this diagnostic procedure were estimated. The report will be of aid to the people planning investments and dealing with questions of reimbursement and other issues of health care policy. The methods of epidemiology, biostatistics, sociology and health economics used by the institutes of social and preventive medicine are very helpful in the procedures of technology assessment.

Importance of databases for technology assessment.

The data indispensable for carrying out the comprehensive, multi-faceted process of medical technology assessment (MTA) should be collected from a variety of sources. The authors distinguish between type "A" general data, useful for assessment but collected without this specific aim, and type "B" data. Registries of health care procedures or of diseases, as well as clinical data bases are quoted as examples of type "B" data, specifically relating to MTA. Since demographic methods are of importance for the evaluation of long-term effects of medical technologies, examples of sources of type "A" data are presented. Their significance for health policy making is discussed.

Appropriateness and necessity research on the Internet: using a "second opinion system".

Appropriateness and necessity research of various procedures in medicine may be the most complex field of innovation in healthcare and technology assessment. Nevertheless, the appropriateness of the indication of any medical intervention is probably more important than the outcome since even ideal quality components of structures, processes and outcomes become irrelevant without a proper indication. The first part of our appropriateness initiative in interventional cardiology and gynecology was to formulate guidelines. To define the appropriateness for coronary angiography, coronary revascularization and hysterectomy, literature-based consensus methods were used. The second part was to disseminate the guidelines in a user-friendly manner via the Internet. Therefore, we relied on a system-driven query facility for propositional (experts) rules. The next part of the appropriateness initiative may be a user-friendly Internet-based data collection system to validate the national accepted guidelines. Most important may be that only data that is needed can be collected using a refined database technology. The described Second Opinion System can be found under: http:sos.inf.ethz.ch. Research on indications with data on clinical outcome may open new opportunities to validate indication guidelines using Internet/database technology for data analysis and browsing of decision graphs concerning clinical decision-making. This new technology facilitates the evaluation of appropriateness and necessity criteria in combination with clinical outcomes.