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Background: Trials of drug therapy for hypertension have shown that such therapy has a clear overall benefit in preventing cardiovascular disease. Although these trials have included slightly more women than men, it is still not clear whether treatment benefit is similar for both sexes., Objective: To quantify the average treatment effect in both sexes and to determine whether available data show significant differences in treatment effect between women and men., Design: Subgroup meta-analysis of individual patient data according to sex. Analysis was based on seven trials from the INDANA (INdividual Data ANalysis of Antihypertensive intervention trials) database and was adjusted for possible confounders., Patients: 20,802 women and 19,975 men recruited between 1972 and 1990., Interventions: Primarily beta-blockers and thiazide diuretics., Results: In women, treatment effect was statistically significant for stroke (fatal strokes and all strokes) and for major cardiovascular events. In men, it was statistically significant for all categories of events (total and specific mortality, all coronary events, all strokes, and major cardiovascular events). The odds ratios for any category of event did not differ significantly between men and women. In absolute terms, the benefit in women was seen primarily for strokes; in men, treatment prevented as many coronary events as strokes. Graphical analyses suggest that these results could be completely explained by the difference in untreated risk., Conclusions: In terms of relative risk, treatment benefit did not differ between women and men. The absolute risk reduction attributable to treatment seemed to depend on untreated risk. These findings underline the need to predict accurately the untreated cardiovascular risk of an individual person in order to rationalize and individualize antihypertensive treatment.

Today, prescribers need to distinguish between the clinical practices based on randomized clinical trialing information and those based on animal physiological data or theory. Now the information on therapeutics is becoming more dense, more complex and less available to the clinicians. Information sources are numerous and varied, including data whose quality differs. These data are unhierarchised in terms of methodological quality and clinical relevance. It will be optimal if each prescriber could himself collect and analyse scientific information. In fact this situation cannot be effective in private physician's practices. An international collaboration, the Cochrane Collaboration, including volunteers, university researchers, and clinical investigators has the following objective: to prepare, maintain and disseminate systematic reviews of the effects of health care. The Cochrane Collaboration is thus the most adapted intermediairy between scientifically actualized data and clinical practitioners.

Reliable syntheses are more and more needed by physicians. In the therapeutic field, this need is illustrated by the growing number of syntheses using meta-analysis tools. Some of these syntheses are based on individual patient data, and this offers three kinds of advantages: the favourable consequences of a collaborative approach, the enhancement of data reliability, and a more complete extraction of useful information thanks to wider analysis potential. Most often, achieving the first two advantages does not require the individual patient data to be available, and a wider analysis potential seems to be the major rationale of such an approach. For instance, the assessment of the variation of treatment effect with along time is more accurate, but may also raise doubts about the validity of some hypotheses, for example, those underlying classical analysis techniques, or at the basis of even acknowledged pathophysiological theory. Ultimately, the concepts of identifying responders (here defined in terms of quantity or quality of life) and identifying the therapy target population are concretely applied in a way that will affect classical medical practice. Tomorrow, drugs will not be prescribed to a hypertensive individual because of the blood pressure level, but considering the size of the predicted therapeutic benefit.

The efficacy of a drug is a quantitative concept rather than a qualitative one. This quantity is expressed by several efficacy indices. None of them meet all the requirements. However, that of absolute benefit is especially suitable for the patients because it tells them the exact gain they can expect from taking the treatment. The absolute benefit varies according to patients' profiles because it interacts with some components of these profiles. In theory, such interactions can be used to predict the size of the absolute benefit for each patient, as well to describe better than with the current tools the therapy target population. We explain why meta-analysis and effect models are means of improving the prediction of the size of the effect and the definition of the therapy target population.

The diagnosis of "white coat" hypertension, the measurement of indices of 24 hour variability of the blood pressure and increased accuracy of blood pressure estimation are some of the advantages of ambulatory blood pressure monitoring. They are part of the reason why the method has been adopted by ambulatory blood pressure monitoring is really useful in the treatment of hypertension is fragile: although the correlation with target organ complications seems better than with conventional blood pressure measurement, it remains to be shown that this information helps to predict and then improve the prognosis of hypertension. With respect to this first stage of demonstration of the added prognostic value attributable to ambulatory blood pressure monitoring, several studies have been undertaken, one of which is OCTAVE II. The goals were to analyse the predictive values of the indices obtained by ambulatory blood pressure monitoring in terms of cardiovascular morbidity and mortality after having described the correlations between these indices and the characteristics of individual patients. Two hundred and sixty six cardiologists, members of the French College of Cardiology, included 3,569 patients in whom an indication for ambulatory blood pressure monitoring had been retained, over a period of 10 months in 1991. These patients were 56.4 year old on average, with 52.6% men, hypertensive or not. The 5 year follow-up should end at the beginning of 1997.

The aim of therapeutic information is that people who need it have access to data of the highest level of evidence. In this context, a message is defined as the medium of information. The conditions for an ideal message to the prescriber are described: its content, the qualities it must meet, and the functional issues it will tackle. An example illustrates the importance of the form of a message. The difference between recommendation and message is highlighted.

The objectives of this sub group meta-analysis on the treatment of hypertension was to: (1) high-light specific results of well-designed trials; (2) group trials according to their specific clinical context; (3) express results of the meta-analysis in absolute reduction terms; and (4) estimate the bias of withdrawal because of blood pressure increase. This meta-analysis is based on summarised published results from randomised controlled trials, comparing a drug treatment versus placebo or no treatment, with morbi-mortality as the principle outcome. The following data were analysed: (1) total mortality; (2) cardiovascular mortality; (3) stroke; (4) major coronary events; and (5) congestive heart failure. The treatment significantly reduced the incidence of all outcomes in trials involving older patients, avoiding up to nine strokes (OR = 0.66, 95% Cl: 0.56-0.77) and four major coronary events (OR = 0.79, 95% Cl: 0.68-0.92) every 1000 patient-years when the bias of withdrawal was taken into account. The only outcome significantly influenced by treatment in younger patients with mild-to-moderate hypertension was stroke, with one stroke avoided every 1000 patient-years (OR = 0.51, 95% Cl: 0.39-0.66). There was insufficient statistical power in the trials which enrolled patients with non-moderate hypertension to reach clinical significance, except for the reduction in the incidence of congestive heart failure. However, the results indicated a trend towards greater absolute benefit under treatment. Trials enrolling patients with post-stroke hypertension also had insufficient power, but suggested benefit by the reduction of the incidence of stroke recurrence and congestive heart failure under treatment. In conclusion, the most constant treatment benefit concerned stroke, although the absolute reduction was very modest in younger patients with mild-to-moderate hypertension. Only the results from trials in older patients showed a significant reduction of major coronary events. Such results need further analyses, ideally based on individual patient data.

The overall effect of antihypertensive drug treatment has been well documented. The proportion of patients who benefit varies according to their baseline cardiovascular risk, and is small for the majority of people treated. Some investigators propose limiting the treatment target population to patients at high cardiovascular risk, but several assumptions must be made to justify this procedure. The INDANA project is a meta-analysis based on individual patient data, and thus offers the opportunity to check the validity of these assumptions. Its main objective is to identify responders (and non-responders) in the drug treatment of hypertension. The rationale and methods for such an approach are presented here, with the solution for some technical problems. The conclusion of the data collection has shown that the project is feasible. The results of the main analysis should be available in 1996, and should contribute to the selection of responders and to the individualization of the treatment of hypertension.

This study evaluated the time for a new, rapid and reliable CK-MB analysis to become positive in myocardial infarction and compared it with classical total CK analyses. Serial analyses of total CK and CK-MB were performed in 49 consecutive patients referred to the Coronary Care Unit for suspected acute myocardial infarction. Twenty of these patients had myocardial infarction with rising enzyme levels, which enabled comparison of the precocity of one analysis compared to another. In these patients, the CK-MB analysis became positive on average 85 to 110 minutes before that of total CK. This result shows that CK-MB analysis can be a diagnostic sign of acute myocardial infarction at an earlier stage than the total CK analysis. The authors discuss the clinical value of this test in difficult indications of fibrinolytic therapy and underline that it enables a more objective assessment of the time of onset of necrosis than clinical data alone.

Since the advent of antibiotics, the bacteriological profile of empyema has changed. It is necessary to recall the recently discovered organisms. Although rarely mentioned in the literature, the Legionnellas may be causative in an empyema. We report a case of empyema to Legionnella bozemanii proven seriologically.