Impact of osmolality on burning sensations during and immediately after intramuscular injection of 0.5 ml of vaccine suspensions in healthy adults

A randomised placebo controlled double-blind cross-over trial was performed on twenty healthy adults to assess the effect of osmolality (300,600,850 and 1100 mOsm) on local tolerance of an intramuscular injection (0.5 ml) of five suspensions containing the same components as the excipients of a combined Diphtheria-Tetanus-acellular Pertussis-inactivated Poliomyelitis-Haemophilus influenzae type b paediatric vaccine (DtacP-IPV-Hib, PENTAVAC). The results did not show any dose-effect relationship between burning or pain sensations and the different osmolalities tested. Although mild and not clinically relevant, these sensations seemed to occur more frequently following injection of an isotonic saline solution (P<0.05). Thus, the osmolality of vaccine like suspensions does not appear to be a potential cause of local pain or burning sensation after their administration.

[Antihypertensive therapy and improved life expectancy without cerebrovascular accident or coronary artery disease]

The absolute benefit from antihypertensive therapy increases with the baseline risk. However, age is a major determinant of cardiovascular risk, so it is important to express therapeutic efficacy with indices for which age is not a confounder. With this aim we explored the expected gain in life expectancy without cardiovascular events according to age at the initiation of the treatment. The treatment effect estimated from the INDANA meta-analysis, was applied to the cardiovascular risk of a French hypertensive population, simulated from national vital statistics. The gain in life expectancy was estimated from the area between survival curves without events. The treatment effect varied according three different hypotheses: increasing, decreasing or constant effect. When assuming a constant treatment effect, our results show a 29 month gain without stroke for a man who began his treatment at 40 years, and 15 months if hypertension is screened and treatment initiated at 75 years. The gains without coronary heart disease are respectively of 11 and 6 months. The variation of treatment effect over time could have a major impact on the treatment benefit. The gain in life expectancy without events is a relevant decision tool, completing usefully the absolute benefit, since it takes into account the influence of age.

The prognostic value of etoposide area under the curve (AUC) at first chemotherapy cycle in small cell lung cancer patients: a multicenter study of the groupe Lyon-Saint-Etienne d'Oncologie Thoracique (GLOT)

PURPOSE

To assess the potential relationships between systemic exposure to doxorubicin, etoposide and ifosfamide at first chemotherapy cycle and therapeutic effect, tumor response, toxicity, and survival, in small cell lung cancer (SCLC) patients.

PATIENTS AND METHODS

Twenty-four patients referred to five different centers with either thorax-limited or metastatic SCLC entered the study. All but one received two induction courses of the 3 day-AVI (doxorubicin 50 mg/m(2) day 1, etoposide 120 mg/m(2) day 1, 2, 3, ifosfamide 2000 mg/m(2) day 1, 2) regimen. Individual plasma samples were collected at the first course and complete concentration data on 24 courses were available. Drugs exposures were estimated using a population pharmacokinetic method and expressed as clearance (Cl), area under the curve (AUC), and AUC-intensity (AUC/cycle duration). Responding patients received thoracic irradiation+concomitant cisplatinum-etoposide (limited disease) or four more courses of AVI (extensive disease). The impact of exposure parameters on haematological toxicity, tumor response and overall survival was assessed using linear regression, the Mann-Whitney U-test and the log-rank test/Kaplan-Meier estimation, respectively.

RESULTS

Twenty-three patients could be evaluated for response and survival. We found no relationship between drug exposure and haematological toxicity but all patients had received Granulocyte-Colony Stimulating Factor support. Tumor response was marginally influenced by ifosfamide AUC. In patients with etoposide AUC>254.8 mg h/l, 1-year survival was 50.0 vs. 9.1% in the other group (median 11.4 vs. 7.1 months, P=0.02), with respect to established prognostic factors. In patients with extensive disease only (n=15), 1-year survival was 42.9 vs. 0% (median 11.3 vs. 5.3 months, P=0.01).

CONCLUSION

This study strongly suggests that SCLC patients should benefit from sufficient etoposide exposure at first cycle to improve survival. Adaptative control based on plasma concentration measurements should be tested in further studies assessing various polychemotherapy regimens.

Low protein diets for chronic renal failure in non diabetic adults

BACKGROUND

For more than fifty years, low protein diets have been proposed to patients with kidney failure. However, the effects of these diets in preventing severe renal failure and the need for maintenance dialysis have not been resolved.

OBJECTIVES

To determine the efficacy of low protein diets in delaying the need to start maintenance dialysis.

SEARCH STRATEGY

Medline and Embase search from January 1966 through to June 1999. Congress abstracts (American Society of Nephrology since 1990, European Dialysis Transplant Association since 1985, International Society of Nephrology since 1987). Direct contacts with investigators.

SELECTION CRITERIA

Randomised trials comparing two different levels of protein intake in adult patients suffering from moderate to severe renal failure, followed for at least one year. Diabetic nephropathy patients were excluded.

DATA COLLECTION AND ANALYSIS

Seven trials were selected from over 40 studies since 1975. A total of 1494 patients were analysed, 753 had received reduced protein intake and 741 a higher protein intake. Collection of the number of "renal deaths" defined as the need for starting dialysis, the death of a patient or a kidney transplant during the trial.

MAIN RESULTS

Two hundred and forty two renal deaths were recorded, 101 in the low protein diet and 141 in the higher protein diet group, giving an odds ratio of 0.62 with a 95% confidence interval of 0.46 to 0.83 (p=0.006). To avoid one renal death, four to 56 patients need to be treated with a low protein diet during one year.

REVIEWER'S CONCLUSIONS

Reducing protein intake in patients with chronic renal failure reduces the occurrence of renal death by about 40% as compared with higher or unrestricted protein intake. The optimal level of protein intake cannot be confirmed from these studies.

Postmenopause hormone treatment in women with NIDDM or impaired glucose tolerance: the MEDIA randomized clinical trial

OBJECTIVE

To assess the biological safety of four hormone replacement treatment (HRT) combinations in women with non insulin dependent diabetes mellitus (NIDDM) or impaired glucose tolerance (IGT).

SUBJECTS AND METHODS

Randomized, double-blind, placebo-controlled trial to analyze the variation of fibrinogen, factor VII, PAI1, and TG blood levels in women (n=99), with NIDDM or IGT, receiving a 3-month course of either oral oestradiol (1 or 2 mg) combined with Chlormadinone Acetate 5 mg, or transdermal oestradiol 50 microg/24 h in association with Norethisterone Acetate (11.2 or 22.4 mg), or placebo. Follow-up lasted 3 months.

RESULTS

Ninety nine patients, mean age 56 years (SD 5), mean diabetes duration 7 years (S.D. 7), mean glycated hemoglobin (7.3%) were enrolled. There was no significant difference between the groups for any of the primary hemostasis criteria (n=77). Triglycerides (TG) variation significantly differed between groups, P=0.01, from -21% in the large patch group, to +22% in the placebo group (n=82). Treatment administration routes did not significantly differ for any of the criteria. There was a significant difference in the total cholesterol variation between groups, from +8.7% in the placebo group to -10.8% in the oral 1 mg group (P=0.001).

CONCLUSION

The treatments had no highly deleterious effect in these patients with NIDDM or with IGT. Long-term trials can be performed with such patients, and an hormone treatment can be prescribed to relieve symptoms. Since these patients had a well-controlled NIDDM, results might be different in less well-controlled diabetes. The data do not support the hypothesis of an impaired oestrogen effect in patients with NIDDM.

Low protein diets delay end-stage renal disease in non-diabetic adults with chronic renal failure

BACKGROUND

The objective of this study was to determine the efficacy of low protein diets in delaying the need to start maintenance dialysis based on an analysis of published literature.

METHODS

The search strategy involved a Medline and Embase search from January 1966 through to June 1999, congress abstracts (American Society of Nephrology since 1990, European Dialysis Transplant Association since 1985, International Society of Nephrology since 1987) and direct contacts with investigators. The selection criteria included randomized trials comparing two different levels of protein intake in adult patients suffering from moderate to severe renal failure, followed for at least 1 year. Patients with diabetic nephropathy were excluded. Seven trials were selected from 40 studies since 1975. A total of 1494 patients were analysed: 753 had received reduced protein intake and 741 a higher protein intake. The numbers of 'renal deaths' (defined as the need for starting dialysis, the death of a patient or kidney transplant during the trial) were collected.

RESULTS

242 renal deaths were recorded, 101 in the low protein diet and 141 in the higher protein diet group, giving an odds ratio of 0.61 with a 95% confidence interval of 0.46 to 0.83 (P=0.006).

CONCLUSION

Reducing protein intake in patients with chronic renal failure reduces the occurrence of renal death by about 40% as compared with larger or unrestricted protein intake. The optimal level of protein intake cannot be confirmed from these studies.

Optimal duration of anticoagulant therapy after an episode of venous thromboembolism

The optimal duration of oral anticoagulant therapy after a first episode of venous thromboembolism (VTE) is still a matter of debate. It is essential to balance the desired effect of the anticoagulants in reducing recurrences against the risk of major bleeding. The aims of this paper are to describe the current concepts in this field. Recent data, based on randomized controlled trials, suggest that it is necessary to tailor the duration of anticoagulation individually according to the topography of VTE and the presence of risk factors. A 6-week treatment for patients with isolated calf vein thrombosis is sufficient. For proximal thrombosis and/or pulmonary embolism, a short anticoagulant course is sufficient in patients with temporary risk factors (3 months), and a longer anticoagulant course (6 months at least) is recommended for cases with permanent risk factors or idiopathic VTE. For these high-risk of recurrence patients, an assessment of low- or fixed-dose oral anticoagulation is necessary in order to reduce the bleeding risk. It is not possible to precisely determine the optimal duration with the available data. We have already performed a meta-analysis on summary data that suggests a long course of oral anticoagulant therapy is superior to a short course. An individual meta-analytic approach is needed to draw more precise conclusions on an interesting and important clinical topic.

Comparison of bioprosthesis and mechanical valves, a meta-analysis of randomised clinical trials

The main purpose of this meta-analysis was to compare the outcomes of patients who randomly received mechanical valves or bioprosthesis, over a long-term clinical follow-up. We found only three trials meeting our selection criteria with a total of 1229 patients (8069. 5 patient-yr). Bleeding was more frequent in patients with mechanical prostheses both after 5 yr (RR=2.6; IC=[1.9;3.5]; P<0.0001) and 11 yr (RR=1.6; IC=[1.2;2.2]; P<0.001) of follow-up. However, the increased risk of bleeding at 11 yr was only statistically significant with mechanical prostheses in the aortic position (RR=1.93; IC=[1.36;2. 74]; P=0.0002). Reoperation was significantly more frequent in patients with bioprosthesis after 11 yr follow-up (RR=0.4; IC=[0.3;0. 6]; P<0.001). Endocarditis was more frequent after 11 yr (RR=0.6; IC=[0.3;0.95]; P<0.05) in patients with mechanical prostheses but these results were heterogeneous between mitral and aortic valves. The choice of valve type does not significantly influence survival.

Population pharmacokinetics of doxorubicin, etoposide and ifosfamide in small cell lung cancer patients: results of a multicentre study

AIMS

To determine the population pharmacokinetic (PK) parameters of doxorubicin (Dox), etoposide (Eto) and ifosfamide (Ifo) in small cell lung cancer (SCLC) patients, to assess the potential relationship between those parameters and to estimate the impact of individual morphological and biological covariates on patients' PK parameters.

METHODS

Twenty-four patients with either SCLC limited to the thorax or extensive SCLC entered the study. All but one received at least two 3 day courses of the standard AVI (Dox 50 mg m-2 day 1, Eto 120 mg m-2 day 1,2,3, Ifo 2000 mg m-2 day 1,2) regimen. Individual blood samples were collected during each course and data on 47 courses were available. Data were analysed with the NONMEM program. Dox, Eto and Ifo plasma concentrations were studied with multicompartment (3, 2 and 2, respectively) models. Inter-individual and interoccasion (course-to-course) variabilities were estimated. The influence of individual covariates (age, sex, stage of the disease, weight, height, body-surface area, serum creatinine, total protein, LDH, ASAT, ALAT, alkaline phosphatase, gamma-GT, bilirubin) on PK parameters was also assessed. Correlations between individual PK parameters of Dox, Eto and Ifo were explored by using Pearson's correlation coefficient.

RESULTS

Multiple data were available for each patient. Dox clearance (CL) and volume of distribution (Vd) were 32.0 l h-1 and 9.3 l (Inter-individual variability: 17.2% and 19.2%). Eto CL (l h-1) and Vd were, respectively, 3.34-0.0083* serum creatinine (micromol l-1) and 6.38 l (interindividual variability: 15.6% and 18.7%). Ifo CL and Vd at day 1 were 5.6 l h-1 and 26.0 l (interindividual variability: 10.1% and 17.2%, respectively). Estimation of course-to-course variability improved the precision of PK models in some cases. No correlation was observed between the respective PK parameters of each drug. Of individual covariates tested, only serum creatinine correlated with Eto CL (r = -0.37, P < 0.001). Self-induction of the metabolism of Ifo was apparent (mean CL increase from day 1 to day 2 : 42%) and individually correlated with the CL value at day 1 (r = -0.61, P < 0.001).

CONCLUSIONS

Assessment of potential relationships between individual systemic exposure of chemotherapy and therapeutic endpoints (tumour response, toxicity and survival) will be required to adjust drugs dosages based on individual PK parameters rather than questionable body-surface area. However, all three drugs in the AVI regimen should be monitored simultaneously.

Oral Beraprost sodium, a prostaglandin I(2) analogue, for intermittent claudication: a double-blind, randomized, multicenter controlled trial. Beraprost et Claudication Intermittente (BERCI) Research Group

BACKGROUND

Beraprost sodium (BPS) is a new stable, orally active prostaglandin I(2) analogue with antiplatelet and vasodilating properties. We report the results of a phase III clinical trial of BPS in patients with intermittent claudication.

METHODS AND RESULTS

Patients (n=549) with a pain-free walking distance of between 50 and 300 m were entered into a 4-week single-blind placebo run-in phase. Patients whose pain-free walking distance had changed by <25% were then randomized to receive either BPS (40 microg TID, n=209) or placebo (n=213) in a double-blind manner for 6 months. Pain-free and maximum walking distances were measured on the occasion of treadmill exercise tests performed at baseline and 1.5, 3, 4.5, and 6 months after randomization. Success was defined as an improvement of >50% in pain-free walking distance at month 6 and in > or =1 earlier treadmill exercise test in the absence of critical cardiovascular events. Success was observed more frequently in the BPS group (43.5%) than in the placebo group (33.3%, P=0.036). Pain-free walking distances increased by 81.5% and 52.5%, respectively, in the BPS and placebo groups (P=0.001) and maximum walking distances by 60.1% and 35.0%, respectively (P=0.004). The incidence of critical cardiovascular events was 4.8% in the BPS group and 8.9% in the placebo group.

CONCLUSIONS

These results show that BPS is an effective symptomatic treatment of patients with intermittent claudication. The beneficial effects of BPS on critical cardiovascular events should be confirmed in appropriate clinical trials.

Streptokinase in acute ischemic stroke: an individual patient data meta-analysis : The Thrombolysis in Acute Stroke Pooling Project

BACKGROUND AND PURPOSE

Three major randomized controlled trials of streptokinase in acute ischemic stroke were curtailed because of safety concerns. The prospective Thrombolysis in Acute Stroke Pooling Project (TAS-PP) was established to examine the aggregate data to identify factors influencing the effect of streptokinase.

METHODS

Individual patient data from the Australian Streptokinase Trial (ASK), Multicentre Acute Stroke Trial-Europe (MAST-E), Multicentre Acute Stroke Trial-Italy (MAST-I), and Glasgow Trial (Glasgow) were pooled. Multivariate modeling determined the interaction between treatment effect and delay from symptom onset to treatment, predicted baseline risk, age, concomitant aspirin or heparin use, and the presence of early CT signs on the outcomes of 10-day death, death and disability, or death alone at 3 or 6 months.

RESULTS

Patients' records were pooled (total 1292 patients; streptokinase, n=653, no streptokinase n=639). The subgroup analysis of treatment effect according to delay from symptoms to inclusion shows only a trend toward a better treatment effect with shorter delay, which is not statistically significant for any outcome. Heavier patients in MAST-E may have had a lower (non significant) risk from the fixed dose of 1.5 million units of streptokinase. Concomitant aspirin increased the excess mortality rates in streptokinase-treated patients (17% without aspirin versus 91% with aspirin, P=0.005). The presence of early CT scan signs did not increase the detrimental effect of streptokinase.

CONCLUSIONS

Few factors influenced the response to streptokinase. However, earlier administration, lower doses of streptokinase, and avoidance of concomitant aspirin should be considered if further streptokinase trials in acute stroke are planned.

Meta-analysis of randomised controlled trials of fluoxetine v. placebo and tricyclic antidepressants in the short-term treatment of major depression

BACKGROUND

Previous meta-analyses of fluoxetine as an antidepressant have many methodological problems, including diagnosis of major depression, validity of outcome measures and lack of intention-to-treat analyses.

AIMS

To provide an estimate of the effect of fluoxetine compared with placebo and tricyclic antidepressants (TCAs), and to investigate reasons for early discontinuation from acute treatment.

METHOD

Randomised trials were analysed using both intention-to-treat, efficacy and end-point.

RESULTS

Fluoxetine was superior to placebo but effect size was low. In trials comparing fluoxetine v. TCA, the results for all trials and for the USA trials showed a trend in favour of fluoxetine. Those for the non-USA trials showed a trend in favour of TCA. When combined, the results showed that significantly fewer patients on fluoxetine discontinued treatment because of adverse events.

CONCLUSION

Fluoxetine is superior to placebo, irrespective of the analytical approach use, whereas the results obtained v. TCAs depend on the approach used. Hence, the results should be interpreted in this light.

Comparison of long versus short duration of anticoagulant therapy after a first episode of venous thromboembolism: a meta-analysis of randomized, controlled trials

OBJECTIVE

To assess the length of oral anticoagulant therapy (short versus long duration) after a first episode of venous thromboembolism (VTE).

DESIGN

Meta-analysis of randomized controlled trials, comparing two durations of anticoagulation, identified in 1999 by a computerized search of the Cochrane Controlled Trial Register, Medline and Embase, completed by an extensive review of the references of pertinent articles.

SETTING AND SUBJECTS

The meta-analysis was performed on literature data. Seven published controlled trials were included. Relative risks with 95% confidence intervals were computed using the relative risk logarithm method. Statistical significance was set up at 0.01 for the test of association.

MAIN OUTCOME MEASURES

Outcomes are major haemorrhage and recurrence after a 12-month follow-up.

RESULTS

For the recurrence end-point (sample size of 2304 patients), a duration treatment of 12-24 weeks seems preferable to a 3-6 week regimen, with a relative risk (RR) of 0.60 (95% CI: 0.45-0.79, P < 0.001). For the major haemorrhage end-point (1823 patients), the RR is not significantly different from 1 (RR = 1.43, 95% CI: 0.51-4.01, P = 0. 5). The results were similar for the subgroup 'permanent risk factors' or 'idiopathic VTE' (RR for recurrence = 0.48, 95% CI: 0. 34-0.68, P < 0.001). The tendency was similar, although not reaching statistical significance, for the 'temporary risk factors' subgroup (RR for recurrence = 0.34, 95% CI: 0.13-0.93, P = 0.035).

CONCLUSIONS

After a first episode of VTE, a long-term treatment regimen allows a significant reduction in the incidence of recurrences without increasing the incidence of bleeding events.

[From clinical trial to prescription]

Clinical trials produce factual data that should be put in practice. This requires that information drawn form their results be transferred to doctors without bias, under a format suited to their training and meeting the constraints of their daily practice. Today this critical step is poorly efficient, despite the availability of techniques and methods appropriate for accessing such information and to tailor it to each patient. Furthermore, regarding many conditions encountered in medical practice, evidence is lacking or is of low strength. Doctors should revise their practice according to the information yielded by clinical trials.

Efficacy of diuretics and beta-blockers in diabetic hypertensive patients. Results from a meta-analysis. The INDANA Steering Committee

OBJECTIVE

To review the effectiveness of diuretic or beta-blocker-based treatment of hypertension in diabetic patients.

RESEARCH DESIGN AND METHODS

A meta-analysis on individual patient data was performed on four trials of the treatment of hypertension in which diabetic patients were included and treated with first-line diuretics or beta-blockers. The main outcomes were the relative risk of death, fatal or nonfatal stroke, fatal or nonfatal coronary events, and major cardiovascular events.

RESULTS

There were 92 diabetic patients who received first-line beta-blockers and 1,008 who received diuretics. In the control groups, diabetic patients had nearly twice the risk of any outcome when compared with nondiabetic patients. The same blood pressure reduction was achieved under treatment in the diabetic and nondiabetic patients, except for systolic pressure, which decreased more in the nondiabetic patients at 1 year. In the 15,843 nondiabetic patients, the risk of all four outcomes was reduced significantly in the treated group. In the 2,254 diabetic patients, the risk reduction was significant only for fatal and nonfatal stroke (36%, P = 0.011) and major cardiovascular events (20%, P = 0.032), but not for death (5%, P = 0.65) and fatal or nonfatal coronary events (15%, P = 0.23). However, no heterogeneity was detected between diabetic patients and nondiabetic patients for any outcome. The numbers of outcomes avoided for 1,000 patients treated for 5 years were higher in diabetic patients (e.g., 38 major cardiovascular events) than with nondiabetic patients (e.g., 28 major cardiovascular events).

CONCLUSIONS

These results show that hypertensive diabetic patients benefit from first-line treatment with diuretics. No conclusion can be drawn for beta-blockers, owing to the small sample size.

Evidence of clinical efficacy of homeopathy. A meta-analysis of clinical trials. HMRAG. Homeopathic Medicines Research Advisory Group

OBJECTIVE

To establish, using a systematic review and meta-analysis, whether there is any evidence from randomised controlled clinical trials of the efficacy of homeopathic treatment in patients with any disease.

DATA SOURCES

Published and unpublished reports of controlled clinical trials available up to June 1998, identified by searching bibliographic databases (Medline, Embase, Biosis, PsychInfo, Cinahl, British Library Stock Alert Service, SIGLE, Amed), references lists of selected papers, hand searching homeopathic journals and conference abstracts, and contacting pharmaceutical companies. TRIALS SELECTION: Trials were selected using an unblinded process by two reviewers. The selection criteria were randomised, controlled trials in which the efficacy of homeopathic treatment was assessed relative to placebo in patients using clinical or surrogate endpoints. Prevention trials or those evaluating only biological effects were excluded. One hundred and eighteen randomised trials were identified and evaluated for inclusion. Sixteen trials, representing 17 comparisons and including a total of 2,617 evaluated patients, fulfilled the inclusion criteria.

DATA EXTRACTION

Data were extracted by two reviewers independently, using a summary form. Disagreements were resolved by a third person.

DATA SYNTHESIS

The evidence was synthesised by combining the significance levels (P values) for the primary outcomes from the individual trials. The combined P value for the 17 comparisons was highly significant P = 0.000036. However, sensitivity analysis showed that the P value tended towards a non-significant value (P = 0.08) as trials were excluded in a stepwise manner based on their level of quality.

CONCLUSIONS

There is some evidence that homeopathic treatments are more effective than placebo; however, the strength of this evidence is low because of the low methodological quality of the trials. Studies of high methodological quality were more likely to be negative than the lower quality studies. Further high quality studies are needed to confirm these results.

[The problem of therapeutic efficacy indices. 3. Comparison of the indices and their use]

Efficacy indices do not contain the same information although they are all combinations of the same two quantities. Therefore, one should choose the proper index. Actually, none is entirely appropriate. Each more or less meets the specifications, depending on the underlying effect model for the therapy considered. However, one can say that the absolute benefit is more appropriate from the patient's point of view, the relative from the scientific point of view and the number of patients to treat from the policy maker's point of view. Nevertheless, this classification needs to be considered with caution. Finally, it emerges from the review that none is fully relevant to express the efficacy of a therapy, even in the most suitable condition, the acute illness.

Risks of untreated and treated isolated systolic hypertension in the elderly: meta-analysis of outcome trials

BACKGROUND

Previous meta-analysis of outcome trials in hypertension have not specifically focused on isolated systolic hypertension or they have explained treatment benefit mainly in function of the achieved diastolic blood pressure reduction. We therefore undertook a quantitative overview of the trials to further evaluate the risks associated with systolic blood pressure in treated and untreated older patients with isolated systolic hypertension

METHODS

Patients were 60 years old or more. Systolic blood pressure was 160 mm Hg or greater and diastolic blood pressure was less than 95 mm Hg. We used non-parametric methods and Cox regression to model the risks associated with blood pressure and to correct for regression dilution bias. We calculated pooled effects of treatment from stratified 2 x 2 contingency tables after application of Zelen's test of heterogeneity.

FINDINGS

In eight trials 15 693 patients with isolated systolic hypertension were followed up for 3.8 years (median). After correction for regression dilution bias, sex, age, and diastolic blood pressure, the relative hazard rates associated with a 10 mm Hg higher initial systolic blood pressure were 1.26 (p=0.0001) for total mortality, 1.22 (p=0.02) for stroke, but only 1.07 (p=0.37) for coronary events. Independent of systolic blood pressure, diastolic blood pressure was inversely correlated with total mortality, highlighting the role of pulse pressure as risk factor. Active treatment reduced total mortality by 13% (95% CI 2-22, p=0.02), cardiovascular mortality by 18%, all cardiovascular complications by 26%, stroke by 30%, and coronary events by 23%. The number of patients to treat for 5 years to prevent one major cardiovascular event was lower in men (18 vs 38), at or above age 70 (19 vs 39), and in patients with previous cardiovascular complications (16 vs 37).

INTERPRETATION

Drug treatment is justified in older patients with isolated systolic hypertension whose systolic blood pressure is 160 mm Hg or higher. Absolute benefit is larger in men, in patients aged 70 or more and in those with previous cardiovascular complications or wider pulse pressure. Treatment prevented stroke more effectively than coronary events. However, the absence of a relation between coronary events and systolic blood pressure in untreated patients suggests that the coronary protection may have been underestimated.

Inter-study variability in population pharmacokinetic meta-analysis: when and how to estimate it?

Population pharmacokinetic analysis is being increasingly applied to individual data collected in different studies and pooled in a single database. However, individual pharmacokinetic parameters may change randomly from one study to another. In this article, we show by simulation that neglecting inter-study variability (ISV) does not introduce any bias for the fixed parameters or for the residual variability but may result in an overestimation of inter-individual (IIV) variability, depending on the magnitude of the ISV. Two random study-effect (RSE) estimation methods were investigated: (i) estimation, in a single step, of the three-nested random effects (inter-study, inter-individual and residual variability); (ii) estimation of residual variability and a mixture of ISV and IIV in the first step, then separation of ISV from IIV in the second. The one-stage RSE model performed well for population parameter assessment, whereas, the two-stage model yielded good estimates of IIV only with a rich sampling design. Finally, irrespective of the method used, ISV estimates were valid only when a large number of studies was pooled. The analysis of one real data set illustrated the use of an ISV model. It showed that the fixed parameter estimates were not modified, whether an RSE model was used or not, probably because of the homogeneity of the experimental designs of the studies, and suggest no study-effect in this example.

Pharmacotherapy for hypertension in women of different races

OBJECTIVES

To assess whether the relative and absolute benefit of hypertension treatment in women varies with age or race.

SEARCH STRATEGY

Literature search of studies from 1966 to 1998 using MEDLINE, reviews, and consultation with experts.

SELECTION CRITERIA

Studies were eligible if they were randomized controlled trials of pharmacological treatment of primary hypertension, with cardiovascular morbidity and mortality outcomes, and with over one hundred women enrolled.

DATA COLLECTION AND ANALYSIS

The pooled population included 23,000 women. Relative risks were combined for each endpoint to form summary risk ratios (RR) using meta-analytic techniques based on a random-effects model. Summary RR's were converted to numbers needed to treat (NNT). Data were dichotomized by age to approximate menopausal status (30 to 54 years, and 55 years and older), and by race (white and African American).

MAIN RESULTS

In women ages 55 years or older (90% white), hypertension treatment results in a 38% risk reduction in fatal and nonfatal cerebrovascular events (95% confidence interval (CI) 27-47%, 5 year NNT 78), a 25% reduction in fatal and nonfatal cardiovascular events (95% CI 17-33%, 5 year NNT 58), and a 17% reduction in cardiovascular mortality (95% CI 3-29%, 5 year NNT 282). In women ages 30 to 54 years (79% white), hypertension treatment results in a 41% risk reduction in fatal and nonfatal cerebrovascular events (95% CI 8-63%, 5 year NNT 264), and a 27% risk reduction in fatal and nonfatal cardiovascular events (95% CI 4-44%, 5 year NNT 259). Hypertension treatment in African American women (mean age 52 years) reduced the risk of fatal and nonfatal cerebrovascular events by 53% (95% CI 29-69%, 5 year NNT 39), fatal and nonfatal cardiovascular events by 45% (95% CI 18-63%, 5 year NNT 21), fatal and nonfatal coronary events by 33% (95% CI 6-52%, 5 year NNT 48), and all cause mortality by 34% (95% CI 14-49%, 5 year NNT 32). Analyses in white women 30 to 54 years old did not show any statistically significant treatment benefit or harm.

REVIEWER'S CONCLUSIONS

Hypertension treatment lowers the relative and absolute risk of cardiovascular morbidity and mortality in women ages 55 years and older, and in African American women of all ages. A greater effort should be made to increase awareness and treatment in these groups of women. Although relative risk reductions for cerebrovascular and cardiovascular events are similar for younger and older women, the NNT of younger women is at least 4 times higher. Decisions for treatment of hypertension in younger white women should be influenced by the individual patient's absolute risk of cardiovascular disease.

Trial summary software

Medical practice is most strongly founded when based on the results of well conducted clinical trials. Clinical trial results normally enter the domain of medical knowledge and practice through their publication in scientific journals. This in itself poses problems of accessibility and selection. The results of this is a slow and selective diffusion of new medical facts which has a consequent cost in human lives and human suffering. In an attempt to shorten this information path initiatives such as the Cochrane collaboration produce and maintain systematic reviews by speciality of the current state of knowledge. The ability to store a representation of a clinical trial in a standard form seems to us to be a necessary condition for the efficient and reproducible preparation of systematic reviews. Furthermore the consequent increased accessibility of research results due to the existence of the summaries would itself be of great use. In this aim a relational database client server system was developed and we publish here the results of our preliminary findings, including the data model, which we feel is an important contribution to the future discussion and development of computer based representations of clinical trial protocols and results and their use in clinical decision making.

Efficacy of treating hypertension in women

OBJECTIVE

To assess whether the relative and absolute benefit of hypertension treatment in women varies with age or race.

DESIGN

Systematic review of studies from 1966 to 1998 using MEDLINE, reviews, and consultation with experts. Eleven randomized controlled trials of pharmacologic treatment of prJgiary hypertension with cardiovascular morbidity and mortality outcomes were selected, with a pooled population of 23,000 women. Relative risks were combined for each end point to form a summary risk ratio using meta-analytic techniques based on a random-effects model. Summary risk ratios were converted to numbers needed to treat (NNTs). Data were dichotomized by age to approxJgiate menopausal status (30 to 54 years, and 55 years and older), and by race (white and African American).

MAIN RESULTS

In women aged 55 years or older (90% white), hypertension treatment resulted in a 38% risk reduction in fatal and nonfatal cerebrovascular events (95% confidence interval [CI] 27%, 47%; 5-year NNT 78), a 25% reduction in fatal and nonfatal cardiovascular events (95% CI 17%, 33%; 5-year NNT 58), and a 17% reduction in cardiovascular mortality (95% CI 3%, 29%; 5-year NNT 282). In women aged 30 to 54 years (79% white), hypertension treatment resulted in a 41% risk reduction in fatal and nonfatal cerebrovascular events (95% CI 8%, 63%; 5-year NNT 264), and a 27% risk reduction in fatal and nonfatal cardiovascular events (95% CI 4%, 44%; 5-year NNT 259). Hypertension treatment in African-American women (mean age, 52 years) reduced the risk of fatal and nonfatal cerebrovascular events by 53% (95% CI 29%, 69%; 5-year NNT 39), fatal and nonfatal cardiovascular events by 45% (95% CI 18%, 63%; 5-year NNT 21), fatal and nonfatal coronary events by 33% (95% CI 6%, 52%; 5-year NNT 48), and all-cause mortality by 34% (95% CI 14%, 49%; 5-year NNT 32). Analyses in white women aged 30 to 54 years did not show any statistically significant treatment benefit or harm.

CONCLUSIONS

Hypertension treatment lowers the relative and absolute risk of cardiovascular morbidity and mortality in women aged 55 years and older and in African-American women of all ages. A greater effort should be made to increase awareness and treatment in these groups of women. Although relative risk reductions for cerebrovascular and cardiovascular events are sJgiilar for younger and older women, the NNT of younger women is at least 4 tJgies higher. Decisions about treatment of hypertension in younger white women should be influenced by the individual patient's absolute risk of cardiovascular disease.

Identification of risk factors in hypertensive patients: contribution of randomized controlled trials through an individual patient database

BACKGROUND

Predicting individual risk is needed to target preventive interventions toward people with the highest probability of benefit over a given time period. We assessed which prognostic factors should be used in predicting risk for hypertensive patients and in searching for treatment modifiers.

METHODS AND RESULTS

Data from 24 390 hypertensive participants who constituted the control groups from 8 controlled trials (1726 deaths over 5 years) were analyzed in multivariate survival models. Outcomes were coronary heart disease death, stroke death, and cardiovascular death. We explored systematically the heterogeneity of results between trials. Left ventricular hypertrophy was electrocardiographically confirmed to be a powerful risk factor and should be included in risk scoring. Height, glomerular filtration rate, and serum uric acid deserve further exploration. Body mass index and heart rate were not confirmed as independent cardiovascular risk factors in this population. The association between male sex and coronary heart disease death was significantly stronger in British cohorts. The lack of prognostic value of diastolic blood pressure was explained by an interaction with age, with a positive association before 65 years and a negative association thereafter. Previous antihypertensive treatment was a significant risk factor.

CONCLUSIONS

Clinical trials provide valuable information for risk prediction. Carefully exploring the heterogeneity among trials is a way to assess the generalizability of findings. This approach, if systematically performed, should increase the ability to identify risk modifiers and to predict individual therapeutic benefit.

[The value of anesthesia consultation in relation to the single preanesthetic visit]

OBJECTIVE

In France, a preanaesthetic assessment (PAA) several days prior to hospital admission for a scheduled surgical or diagnostic procedure under anaesthesia, associated with a preanaesthetic visit (PAV) the day before, are compulsory. This study aimed at comparing the benefits of PAA with those of a PAV not preceded by a PAA.

STUDY DESIGN

Prospective, controlled, randomized study.

PATIENTS

The study included 296 patients undergoing either a urologic, or ophthalmologic, or ENT procedure, randomly allocated either to a PAA (followed by a PAV) group or a PAV (without previous PAA) group.

METHODS

The main criterion of comparison was the duration of preanaesthetic hospital stay and the secondary criteria were the incidence of procedure postponements and patients' satisfaction respectively.

RESULTS

In the PAA group, the preanaesthetic hospital stay was shorter by 0.4 days (P = 0.001). Out of the 19 postponed procedures (7%), the cause of postponement was a medical one in 15 patients: 13 in the PAV group and 2 in the PAA group respectively (P = 0.009). The PAA was not considered as a constraint by most patients.

CONCLUSION

The PAA shortens the duration of preanaesthetic hospital stay and decreases the incidence of procedures postponed for a medical cause.