Probing the plasma near high power wave launchers in fusion devices for static and dynamic electric fields (invited).

An exploratory study was carried out in the long-pulse tokamak Tore Supra, to determine if electric fields in the plasma around high-power, RF wave launchers could be measured with non-intrusive, passive, optical emission spectroscopy. The focus was in particular on the use of the external electric field Stark effect. The feasibility was found to be strongly dependent on the spatial extent of the electric fields and overlap between regions of strong (>∼1 kV/cm) electric fields and regions of plasma particle recycling and plasma-induced, spectral line emission. Most amenable to the measurement was the RF electric field in edge plasma, in front of a lower hybrid heating and current drive launcher. Electric field strengths and direction, derived from fitting the acquired spectra to a model including time-dependent Stark effect and the tokamak-range magnetic field Zeeman-effect, were found to be in good agreement with full-wave modeling of the observed launcher.

Dynamic Stark spectroscopic measurements of microwave electric fields inside the plasma near a high-power antenna.

Fully dynamic Stark effect visible spectroscopy was used for the first time to directly measure the local rf electric field in the boundary plasma near a high-power antenna in high-performance, magnetically confined, fusion energy experiment. The measurement was performed in the superconducting tokamak Tore Supra, in the near field of a 1­3 MW, lower-hybrid, 3.7 GHz wave-launch antenna, and combined with modeling of neutral atom transport to estimate the local rf electric field amplitude (as low as 1­2 kV/cm) and direction in this region. The measurement was then shown to be consistent with the predicted values from a 2D full-wave propagation model. Notably the measurement confirmed that the electric field direction deviates substantially from the direction in which it is launched by the waveguides as it penetrates only a few cm radially inward into the plasma from the waveguides, consistent with the model.

Synergy of electron-cyclotron and lower-hybrid current drive in steady-state plasmas.

Improvement (up to a factor of approximately 4) of the electron-cyclotron (EC) current drive efficiency in plasmas sustained by lower-hybrid (LH) current drive has been demonstrated in stationary conditions on the Tore Supra tokamak. This was made possible by feedback controlled discharges at zero loop voltage, constant plasma current, and constant density. This effect, predicted by kinetic theory, results from a favorable interplay of the velocity space diffusions induced by the two waves: the EC wave pulling low-energy electrons out of the Maxwellian bulk, and the LH wave driving them to high parallel velocities.

Antidepressant medication and suicide in Sweden.

OBJECTIVE: To explore a possible temporal association between changes in antidepressant sales and suicide rates in different age groups. METHODS: A time series analysis using a two-slope model to compare suicide rates in Sweden before and after introduction of the selective serotonin reuptake inhibitors, SSRIs. RESULTS: Antidepressant sales increased between 1977-1979 and 1995-1997 in men from 4.2 defined daily doses per 1000 inhabitants and day (DDD/t.i.d) to 21.8 and in women from 8.8 to 42.4. Antidepressant sales were twice as high in the elderly as in the 25-44-year-olds and eight times that in the 15-24-year-olds. During the same time period suicide rates decreased in men from 48.2 to 33.3 per 10(5) inhabitants/year and in women from 20.3 to 13.4. There was significant change in the slope in suicide rates after the introduction of the SSRI, for both men and women, which corresponds to approximately 348 fewer suicides during 1990-1997. Half of these 'saved lives' occurred among young adults. CONCLUSION: We demonstrate a statistically significant change in slope in suicide rates in men and women that coincided with the introduction of the SSRI antidepressants in Sweden. This change preceded the exponential increase in antidepressant sales.

Self-poisonings with drugs by adolescents in the Lund catchment area.

Our objective was to investigate which drugs young people who attempt suicide use in the Lund catchment area-eight municipalities in Skåne, southern Sweden. All patients aged up to 18 years admitted to Lund University Hospital after deliberate or probably deliberate self-poisoning from 1 January 1991 until 31 December 1995 were included. Forty-nine (58%) had used a single drug; 20 (24%) had used 3 or more drugs. Fifty-two (61%) used analgesics-paracetamol was used by 38 (45%) and propoxyphene by 17 (20%). Thirty-one (36%) had ingested psychotropics-13 used benzodiazepines, 10 antidepressants, and 8 antipsychotics. Eleven (15%) had used drugs in combination with alcohol. We conclude that it is important to follow changes in self-poisoning patterns, to monitor the effects of preventive work and discover new trends in drug use.

Prescribing patterns for analgesics in relation to underprivileged area (UPA) score, mortality and suicide in 33 municipalities in the province of Skåne, southern Sweden.

BACKGROUND: Although it is well known that analgesics contribute to suicide, there is little knowledge about how much of the mortality and suicide can be explained by socioeconomic deprivation or by sales of analgesics. METHODS: This ecological study analyses the relationships between the sales (defined daily doses per 1000 inhabitants per day) of dextropropoxyphene, dextropropoxyphene combinations, paracetamol, codeine and paracetamol combinations, and other codeine combinations and the Swedish UPA (underprivileged area) score, mortality and suicide rates in 33 municipalities in Skåne in 1987 and 1994 for people aged 20-64 years. The association of each of the subgroups of analgesics with all-cause mortality, and with standardised mortality rates for suicide, adjusted for UPA score, was investigated by using weighted (by population size) regression analysis. RESULTS: In 1994 there was a moderate to strong significant correlation between sales of analgesics and UPA scores, mortality and suicide (r = 0.49-0.78). Although UPA score explained 68.9% and 67.4% respectively of the variance between the analgesics and all-cause mortality and suicide, codeine and paracetamol combinations explained a further 10.1% of the variance in suicide. Dextropropoxyphene and codeine and paracetamol combinations explained an additional 3.8% and 2.9% respectively of the variance in mortality. CONCLUSIONS: Local prescription rates for analgesics were associated with mortality and suicide, when adjusted for socioeconomic deprivation defined as UPA score.

'Open-ended questions' and 'show-and-tell'--a way to improve pharmacist counselling and patients' handling of their medicines.

Pharmacists must ensure that patients know how to make the best use of their medication. An education programme was initiated in the southernmost part of Sweden during 1990 in order to improve the communication skills of pharmacy staff and the information given to customers. Customers with prescriptions for Turbuhaler were asked to 'show-and-tell' how they used their inhalers, and the results were documented. In April 1992, 53% of patients handled their Turbuhaler correctly. One year later a significantly higher proportion of the patients (67%) used their inhalers correctly. If patients are asked to 'show-and-tell' how they use their medication and how they interpret the information given, then errors in their handling of the medicines can be revealed. If advice on the proper use of drugs is given to individual patients, then mishandling is reduced. The study used an open design, so the conclusions drawn can only be tentative. However, the magnitude of the change observed suggests that the conclusions are valid.

Increased risk of ischaemic heart disease mortality in elderly men using anxiolytics-hypnotics and analgesics. Results of the 10-year follow-up of the prospective population study "Men born in 1914", Malmo, Sweden.

OBJECTIVES: An increased risk of all-cause and cardiovascular mortality in users of anxiolytic-hypnotic drugs (AHD) has been reported, and use of analgesics may be an additional factor. Therefore, we examined the association of AHD and analgesic use, alone and in combination, with all-cause and ischaemic heart disease (IHD) mortality. METHODS: Multivariate 10-year survival analysis in a population based cohort of 500 men born in 1914. Relative risks (RR) were adjusted by relevant confounders (blood pressure, serum cholesterol, diabetes mellitus, smoking habit, high alcohol consumption, history of previous IHD, cancer, and other diseases). RESULTS: The RR of both all-cause and IHD mortality were significantly increased among those using both AHD and analgesics compared to those who took neither of these drugs: RR = 1.8 for all-cause mortality, and RR = 2.7 for IHD mortality. CONCLUSION: Although the number of cases was small, warranting interpretative caution, the current study suggests that the combined use of AHD (mainly benzodiazepines) and analgesics seems to be associated with an increase in all-cause and IHD mortality in elderly men.

Sales of tranquillizers, hypnotics/sedatives and antidepressants and their relationship with underprivileged area score and mortality and suicide rates.

OBJECTIVE: This study analyses the correlation between the Swedish underprivileged area score and sales of tranquillizers, hypnotics/sedatives, neuroleptics and antidepressants, and the correlation between these sales and mortality and suicide rates, with the aim of using sales data to identify areas with poor socioeconomic conditions. SETTING: Southern Sweden, 33 municipalities in Skåne, 1987 and 1994. DESIGN: Ecological study. Determined and undetermined cases of suicide were taken from the local death register for the years 1987-1993. Suicide rates (determined and undetermined cases) were calculated as the ratio between observed and expected number of suicides. Mortality for people aged 20-64 years was calculated from life tables for the decade 1981-1990. The underprivileged area score was calculated for municipalities using the proportion of persons in the following groups: elderly living alone, under 5 years of age, one-parent families, unskilled, unemployed, living in crowded households, those moving house in the previous year, and ethnic groups. After transformation (square root of arc sine) and standardization, each of the eight variables was weighted by the British general practitioners average weighting and added to give the underprivileged area score. The selection of the eight variables was based on general practitioners' perceptions of the effect of the social characteristics of the populations in their respective residential areas on their workload or pressure on services. The total drug sales figures for tranquillizers, hypnotics/sedatives, neuroleptics and antidepressants are expressed in Defined Daily Doses per 1000 inhabitants per day. The relationship between these variables was analysed using Pearson's correlation coefficient. RESULTS: There was a moderate correlation (0.41-0.68) between the sales expressed as in Defined Daily Doses per 1000 inhabitants per day of tranquillizers and hypnotics/sedatives and underprivileged area score. Furthermore, the sales of tranquillizers and hypnotics/sedatives seemed to be moderately correlated with both mortality (0.44-0.67) and suicide (0.47-0.58). CONCLUSION: Sales of tranquillizers or hypnotics/sedatives could be used with caution as markers for socioeconomic conditions on the basis of their moderate ecological correlation with a composite socioeconomic index such as the Swedish underprivileged area score and their moderate correlation with mortality and suicide.

Drug prescription attitudes and behaviour of general practitioners. Effects of a problem-oriented educational programme.

A producer-independent, problem-oriented, group-education programme with 2-day meetings on drug treatment in primary health care (PHC) was developed and evaluated. Initially, it was tested on a selected group of general practitioners (district physicians), using a non-exposed group as control. A comprehensive questionnaire was used to test changes in attitudes. There was a significant change in attitudes concerning both general opinions on drugs and drug use, on information about drug treatment, and on use of drugs in selected therapeutic areas. Also, the district physicians became more critical towards information from pharmaceutical companies. Prescribing patterns tended to change in accordance with the attitude changes. Subsequently, the programme was offered to all district physicians (about 550) in the southern Swedish health care region for a 10-year period, with 20-25 district physicians per 2-day meeting. The impact of the programme on the prescribing of a selected group of drugs (antibiotics) was assessed by voluntary registration of prescription by the participants, by regional prescription analyses and by analyses of drug sales data. There were significant, consistent, and sustained changes in the prescribing of antibiotics. The study supports the view that, if drug prescribing in general practice is to be improved, producer-independent, problem-oriented, face-to-face, small-group education on drug treatment is worthwhile.

Antibiotics prescription in primary care: a 5-year follow-up of an educational programme.

An educational programme on the use of antibiotics for respiratory tract infections (RTIs) in primary care, initiated among district physicians at the Community Health Centre of Höör, Sweden in 1985, resulted in an overall reduction in prescriptions for antibiotics, particularly broad-spectrum antibiotics. The aim of the present study was to evaluate the long-term effects of the programme on antibiotic prescription patterns at the centre. Since 1985, computerized records have been kept of every consultation at the centre, including details of the attending physician, the patient, diagnosis and type of antibiotic prescribed. Moreover, during a 3-month period in 1991, each pharmacy in the region recorded details of all prescriptions for antibiotics dispensed. Estimated immediately after the programme, the proportion of RTI patients prescribed antibiotics had fallen to 44%, a figure virtually unchanged 5 years later. During the subsequent five-year period, antibiotics dispensed at the pharmacy in Höör were further reduced from 14.1 to 13.2 defined daily doses 1000 inhabitants-1 day-1. As compared with district physicians at other community health centres in the region, those at Höör prescribed more penicillin V (80% of all antibiotic prescriptions) and less broad-spectrum antibiotics. The educational programme, combined with an active interest among district physicians at Höör in current research into antibiotic usage, has thus wrought enduring changes in the pattern of antibiotic prescription. A probable contributory factor was the district physicians' awareness that the computerized registration of diagnosis and treatment enables prescription patterns to be audited at an individual level.

Medicine self-poisoning and the sources of the drugs in Lund, Sweden.

The purpose of this study was to investigate the prevalence of toxic agents in attempted and completed suicides. The purpose was also to explore the sources of the drugs taken by suicide attempters. Verbal information on drug intake was collected from 280 suicide attempters during 1987-1990 in the Lund-Orup catchment area. Information on the sources of the drugs was collected from 143 of these attempters. The study also includes toxicological screening from 73 fatal poisonings in southern Sweden during 1989. According to verbal information, the most common drugs used by suicide attempters were benzodiazepines (51%), analgesics (29%) and antidepressants (20%). In suicide attempters, diazepam and levomepromazine were reported more than expected from prescription data. Toxicological screenings of fatal poisonings showed that benzodiazepines were most common (55%), followed by analgesics (38%), mainly propoxyphene (29%) and antidepressants (30%), mainly amitriptyline (22%). Amitriptyline and diazepam were more commonly detected in completed suicides than expected from prescription data. The most common sources of drugs to attempted suicides were physicians, and especially psychiatrists. We therefore conclude that continuous information to physicians on drug overdose is important, and it is also important to introduce alternative strategies to prevent suicidal behaviour.

Benzodiazepine prescribing patterns in a high-prescribing Scandinavian community.

Sales statistics indicate large variations in benzodiazepine consumption between the Scandinavian countries: the current difference between Denmark (highest) and Sweden (lowest) is almost two-fold. There are also large within-country variations: e.g. benzodiazepine sales in the Swedish city of Helsingborg, which is close to Denmark, were at the average Danish level and were the highest in Sweden. Repeated prescription analyses were carried out in Helsingborg, and register data were used to compare the extent of psychiatric morbidity and psychosocial problems in this city with those in neighbouring cities. Benzodiazepine consumption was higher than the national average in all age groups. However, neither the choice of the predominant benzodiazepine agents nor the dose size or number of doses per prescription showed any major deviation. Hence, Helsingborg may have a larger proportion of benzodiazepine users or longer exposure periods among users. The latter is supported by the fact that about 40% of all benzodiazepine prescriptions were repeated. Psychiatric morbidity, suicide rate, alcohol-related diseases, unemployment and the proportion of socially isolated subjects were higher than the county average. On the other hand, within the county, there were cities that despite lower benzodiazepine sales had an equal or higher rate of suicide, unemployment and alcohol-related diseases. Of all benzodiazepine prescriptions processed in Helsingborg, > 30% were issued by < 5% of the prescribers (> or = 15 prescriptions per prescriber and per week). Thus, the higher usage of benzodiazepines in Helsingborg may partly be related to higher psychiatric morbidity and more psychosocial problems, but deviant prescribing habits among a minority of physicians are also important.