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PubMed1997

[Practical clinical implications of megastudies for primary prevention].

The results of different meta-analyses conducted in primary prevention have shown an insignificant difference in total mortality or coronary heart disease (CHD) mortality; and only two studies have shown differences in the incidence of CHD. The WOS study, the first study in primary prevention done with statines, observed a 20% reduction in the total cholesterol, a relative risk reduction of 31%, an absolute risk reduction of 2.4% and the number of patients who needed to be treated, to prevent coronary disease during a five year period, was 42. Subgroup analyses showed a greater benefit for high risk patients: smokers and those with peripheral vascular disease. This is why the utilization of a cardiovascular risk estimation, instead of isolated cholesterol levels or other risk factors, is currently recommended. However, it is important to bear in mind that the results of the WOS study cannot be easily extrapolated to Spain because the rates of CHD are much lower here than the ones observed in Scotland. Promotion of treatment of high risk patients with statines must be accompained by a promotion of a healthy lifestyle at both the individual and the community level.

Coronary Disease↗

PubMed1997

[Role of adjuvant chemotherapy in the treatment of soft tissue sarcoma].

Important improvements in local control with increasing function-sparing treatment have been achieved in adult soft tissue sarcomas (STS). However, the global prognosis of these diseases remains poor and 40% of patients with STS currently die of metastases within 5 years. In fact, the impact of chemotherapy remains debated, particularly in the adjuvant setting. Thirteen randomized clinical trials with no-treatment control arms have been published to assess adjuvant chemotherapy. A benefit has been demonstrated in 2 studies for overall survival, and in 5 studies when considering disease-free survival (DFS). Globally, despite large differences between studies (patient selection and treatment modalities), overall survival, DFS and local control of the chemotherapy arm were always better than those of the observed arm. These effects were also confirmed in 3 meta-analyses on published data. However, according to the preliminary results of a meta-analysis on individual patient data, overall survival does not appear to be significantly affected. Therefore, adjuvant chemotherapy for STS remains investigational. Randomized studies have to be pursued on the basis of previously performed trials in order to assess which patient group really benefits from adjuvant chemotherapy.

Actuarial Analysis↗

PubMed1997

Combined-modality therapy of head and neck cancer.

The treatment of head and neck cancer has traditionally consisted of surgery with postoperative radiation therapy. Chemotherapy has been reserved for palliation. In recent years, induction chemotherapy has been shown to allow for larynx preservation in patients with laryngeal or hypopharyngeal cancer. Concomitant chemoradiotherapy has been shown to provide a statistically significant survival benefit in selected studies and recent meta-analyses. In patients with nasopharyngeal cancer, the use of cisplatin and concomitant radiation therapy results in a marked survival benefit.

Antineoplastic Agents↗

PubMed1997

Paclitaxel/carboplatin plus ifosfamide in non-small cell lung cancer.

Chemotherapy has a positive role in managing patients with stage IV non-small cell lung cancer. Randomized studies and meta-analyses comparing chemotherapy with best supportive care have confirmed a significant prolongation of survival for chemotherapy-treated patients. In recent years, several new active agents have been identified. These include the taxanes paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) and docetaxel, the antimetabolite gemcitabine, the mitotic spindle inhibitor vinorelbine, and (potentially) the topoisomerase I inhibitors. Combinations of either vinorelbine or paclitaxel with cisplatin have resulted in a significant increase in median survival times compared with both cisplatin and vindesine and cisplatin and etoposide. Paclitaxel combined with either carboplatin or ifosfamide also has been promising. Since even the best current combination regimens result in median survival times of less than 1 year, the identification of more active drugs and combinations remains a high priority. One possible strategy to identify more active regimens may be the combination of three rather than two active agents into a combination regimen. Although the three-drug regimens used in the 1980s appeared to be no more active than two-drug combinations, the advent of additional active compounds with novel mechanisms of action allows this question to be readdressed. Based on this background, we have initiated a phase I/II study of carboplatin and paclitaxel with escalating doses of ifosfamide. The study design and dosing schedule are discussed in this report.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

Low- versus high-dose aspirin in prevention of ischemic stroke.

Aspirin is the most extensively studied drug for the prevention of ischemic vascular disease. Meta-analyses confirm that aspirin is effective in prevention of ischemic events, including stroke. Recently, there has been considerable discussion about the best dose of aspirin to prevent stroke. Several studies tested aspirin in a daily dose of 975 mg or more alone or in combination with another drug, most commonly dipyridamole, and noted that aspirin was effective. Successively lower doses of aspirin were tested and recent studies demonstrate that low doses (< 100 mg/day) are effective. Only one study, enrolling patients with transient ischemic attack or minor stroke, has examined aspirin in a daily dose of approximately 325 mg. Side effects of aspirin are dose related; gastrointestinal bleeding and epigastric pain are less with low doses. Available data cannot confirm that low doses (< 100 mg/day) of aspirin are either more or less effective than larger (975 mg/day) doses. A direct comparison of the usefulness of low doses (< 100 mg/day) or large doses (approximately 1,000 mg/day) in patients at high risk of stroke is needed. Until the results of such a study are known, the better safety profile of low doses favors aspirin in a daily dose of 100 mg or less.

Animals↗

PubMed1997

Cost-effectiveness of the clinical practice recommendations in the AHCPR guideline for smoking cessation. Agency for Health Care Policy and Research.

CONTEXT: The Agency for Health Care Policy and Research (AHCPR) published the Smoking Cessation: Clinical Practice Guideline in 1996. Based on the results of meta-analyses and expert opinion, the guideline identifies efficacious interventions for primary care clinicians and smoking cessation specialty providers. OBJECTIVE: To determine the cost-effectiveness of clinical recommendations in AHCPR's guideline. DESIGN: The guideline's 15 recommended smoking cessation interventions were analyzed to determine their relative cost-effectiveness. Then, using decision probabilities, the interventions were combined into a global model of the guideline's overall cost-effectiveness. PATIENTS: The analysis assumes that primary care clinicians screen all presenting adults for smoking status and advise and motivate all smokers to quit during the course of a routine office visit or hospitalization. Smoking cessation interventions are provided to 75% of US smokers 18 years and older who are assumed to be willing to make a quit attempt during a year's time. INTERVENTION: Three counseling interventions for primary care clinicians and 2 counseling interventions for smoking cessation specialists were modeled with and without transdermal nicotine and nicotine gum. MAIN OUTCOME MEASURE: Cost (1995 dollars) per life-year or quality-adjusted life-year (QALY) saved, at a discount of 3%. RESULTS: The guideline would cost $6.3 billion to implement in its first year. As a result, society could expect to gain 1.7 million new quitters at an average cost of $3779 per quitter, $2587 per life-year saved, and $1915 for every QALY saved. Costs per QALY saved ranged from $1108 to $4542, with more intensive interventions being more cost-effective. Group intensive cessation counseling exhibited the lowest cost per QALY saved, but only 5% of smokers appear willing to undertake this type of intervention. CONCLUSIONS: Compared with other preventive interventions, smoking cessation is extremely cost-effective. The more intensive the intervention, the lower the cost per QALY saved, which suggests that greater spending on interventions yields more net benefit. While all these clinically delivered interventions seem a reasonable societal investment, those involving more intensive counseling and the nicotine patch as adjuvant therapy are particularly meritorious.

Adult↗

PubMed1997

[The recent progress in chemoradiotherapy of lung cancer].

This is a review of the recent progress in chemoradiotherapy of locally advanced lung cancer. In the limited disease stage of small cell lung cancer, a meta-analysis showed patients treated with a combination of chemotherapy and radiotherapy have a statistically significantly longer survival than those with chemotherapy alone. However, the timing of the combination of radiation and chemotherapy has not been clarified. One study favored late over early use of radiotherapy for survival. Another randomized study and a meta-analysis revealed earlier radiotherapy had a better prognosis. JCOG performed a randomized phase III study comparing concurrent chemoradiotherapy with chemotherapy followed by radiotherapy, and the final results will be published in the near future. In the past, radiotherapy alone had been considered standard therapy for inoperable locally advanced non-small cell lung cancer. Several randomized studies and meta-analyses demonstrated the combination of chemotherapy and radiotherapy produced better survival rates than by radiotherapy alone. Our randomized study indicated the addition of radiotherapy after chemotherapy is superior in long-term survival to chemotherapy alone. The West Japan Lung Cancer Group conduct a phase III randomized study comparing concurrent and sequential chemoradiotherapy, and the determination of survival is now in the follow-up stage. The role of induction chemoradiotherapy before surgical resection, comparison of chemoradiotherapy with induction chemoradiotherapy followed by surgery, and the effects and safety of the combination of new drugs and radiotherapy are now under investigation.

Antineoplastic Agents↗

PubMed1997

[Treatment of chronic cardiac insufficiency with coenzyme Q10, results of meta-analysis in controlled clinical trials].

Meta-analysis applied to eight controlled clinical trials of coenzyme Q10 (CoQ10)-treatment of congestive heart failure revealed a significant improvement a several important cardiac parameters such as ejection fraction (EF), stroke volume (SV), cardiac output (CO), cardiac index (CI) and end diastolic volume index (EDVI). Concerning the improvement in SV and CO the average patient in the CoQ10 group had a higher score than respectively 76% and 73% of the patients in the placebo group. The improvement in CO and SV was also significant when considering of homogeneity. Additional controlled clinical trials seem justified which may strengthen the power of the meta-analyses. However, based on available results, it can not be excluded that CoQ10 may have a future role a adjunctive therapy in a dosage of 100-200 mg/day in the treatment of chronic congestive heart failure.

Antioxidants↗

PubMed1996

Mammography screening under 50: a limited perspective on a multifaceted issue.

Navarro and Kaplan's article on the cost-effectiveness of mammography screening for women under 50 offers a limited perspective on a complex and rapidly evolving issue. They suggest that eliminating mammography benefits for younger women will result in the delivery of other important women's health services, but they provide no data on the cost-effectiveness of these programs compared to mammography. Four other areas of omission significantly limit this article's scope and potential impact. Navarro and Kaplan do not discuss: 1) increasing breast cancer incidence in women under 50, particularly in African-American women; 2) the importance of breast cancer risk in relation to mammography screening; 3) the relevance of meta-analyses of randomized clinical trials done by other investigators; and 4) the heterogeneity of mammography screening recommendations in clinical practice.

Adult↗

PubMed1997

Aminoglycosides are useful for severe respiratory tract infections.

Clinical trials comparing the efficacy of monotherapy with aminoglycosides versus beta-lactams suggest that standard multiple-daily dosing regimens of aminoglycosides are less effective than the newer broad-spectrum beta-lactams, especially against Pseudomonas aeruginosa. However, the addition of an aminoglycoside to a beta-lactam has increased survival in patients with gram-negative bacteremia, particularly in those with hypotension and severe illness. This reduction in mortality has not yet been observed with other popular combinations, such as the fluoroquinolones with beta-lactams. The ability of aminoglycosides to prevent the emergence of resistance is less well documented. Newer studies on the pharmacodynamics of antimicrobials have shown that once-daily dosing optimizes the efficacy and minimizes the toxicities of aminoglycosides. Meta-analyses of large numbers of clinical trials have suggested that this method of drug administration can facilitate the increased usage of the aminoglycosides while limiting nephrotoxicity and the cost of antimicrobial therapy. The use of aminoglycosides by once-daily dosing for adjunctive therapy in severe respiratory tract infections is both efficacious and safe.

Aminoglycosides↗

PubMed1998

Silicone breast implants and autoimmune disease.

In 1992, the Food and Drug Administration requested a voluntary moratorium on the scale and implantation of silicone-gel-filled breast implants because of growing concern over the lack of scientific and clinical data supporting their safety and effectiveness. Breast implants had been reported to cause serious local complications, and new questions about breast implants and increased risk for autoimmune disease, including the rare but sometimes fatal connective tissue disease scleroderma, were also raised. Since that time, clinical studies have focused on the adjuvant effect of silicone and of potential autoantibody production. Epidemiologic studies have ruled out a large increased risk for connective tissue disease overall in women with breast implants, but samples were too small to rule out an increase in rare connective tissue diseases. Nor were studies properly designed to address whether an atypical syndrome might develop in women with breast implants. Meta-analyses of these studies cannot remedy their underlying methodologic weaknesses. While the question of whether rare connective tissue disease is associated with breast implants may never be answered definitively, recent progress in identifying new syndromes such as fibromyalgia and chronic fatigue syndrome may provide an insight into methodology for evaluating the existence of a silicone-related syndrome in women with breast implants.

Autoimmune Diseases↗

PubMed1997

Variability in treatment-seeking cocaine abusers: implications for clinical pharmacotherapy trials.

The two examples provided in this chapter suggest that the inconsistent findings across studies evaluating identical pharmacologic agents may be associated with variations in sample characteristics, particularly those associated with (a) general treatment responsiveness (e.g., severity of cocaine use, sociopathy), or (b) responsiveness to specific treatment strategies (e.g., rates of depression where antidepressant agents are evaluated). Describing study samples and evaluating treatment response along multiple dimensions, using a common set of standardized assessments, would be an important advance in understanding variation in subjects' response to medication effects and comparison of findings across different studies. Moreover, consistent description of study samples across a number of dimensions would set the stage for meta-analyses of patient-treatment interactions. Similarly, as new medications are developed and evaluated, variables that have a theoretical basis as mediators of treatment response should be identified and evaluated. It should be noted, however, that success profiling and matching research is more complex than the search for simple main effects (Finney and Moos 1986; Project MATCH Research Group 1993). In particular, adequate power to detect patient-treatment interactions requires much larger sample sizes than those that have to date characterized pharmacotherapy research for cocaine dependence. This strategy, however, is likely to enhance the development of effective pharmacological interventions for this very challenging patient population as researchers' understand the complex processes associated with treatment seeking, retention, and outcome among cocaine abusers.

Clinical Trials as Topic↗

PubMed1997

[Early postpartum discharge in the postpartum].

OBJECTIVE: To assess a policy of early discharge from hospital after a vaginal birth. DATA SOURCES: Reports of studies on this topic were identified in Medline and Cochrane Collaboration database (from 1985 to the beginning of 1995, in english or latin publications). This search was supplemented by referenced studies in book chapters and in other published bibliographies. Key words were: early discharge or ambulatory care and mother or infant or post-partum or obstetrics. STUDY SELECTION: One hundred and ten articles have been retrieved. We have included in the meta-analyse the randomized clinical trials comparing a group of women discharged early (less than 48-72 hours after delivery) with a control group leaving hospital after an usual stay (more than 48-72 hours). Quality of the studies was analysed through the Chalmers et al. recommendations. DATA EXTRACTION: Data were retrieved independently by two authors, and results were compared. Selected outcomes were: hyperbilirubinemia, infant feeding problems and skin rashes; breast feeding; maternal satisfaction on the hospital stay; readmission and non-routine clinics for both the mother and her child. DATA SYNTHESIS: Data from five included studies were pooled by the Peto method. There are no significant modifications of the risks of re-admission to hospital. The frequency of non-routine clinics and the risk of skin rash are not different in the two groups. The risk of hyperbilirubinemia and infant food problems are not different. The frequency of breastfeeding one month after delivery was higher in the early discharge group (OR = 1.88; 95% CI: 1.09-3.23), but this difference decreased over time. Women satisfaction on hospital stay was lower in case of early discharge (OR = 0.56; 95% IC: 0.44-0.72). CONCLUSION: The meta-analysis suggests an advantage of early discharge policy on breastfeeding at one month after the delivery, but mothers seem to prefer longer hospital stays. These results must be cautiously interpreted as included studies are of small sample size or rather old. This policy remains to be evaluated more thoroughly before recommendations could be made.

Attitude to Health↗

PubMed1997

Accumulating scientific evidence in cardiology with special reference to the Japanese contribution.

Clinical practice guidelines have been released as a current summary of the most recent scientific evidence in various areas. The paradigm by which evidence is regarded important is called evidence-based medicine (EBM). Sources of EBM are valid randomized controlled trials (RCT) and meta-analyses (MA). Only well-qualified studies should be used for the EBM. The characteristics for both RCTs and MAs are considered. controversial issues are also discussed, such as the safety of calcium channel blockers and the efficacy of magnesium for acute myocardial infarction. Finally, Japanese RCTs, either finished or ongoing, are summarized. International collaboration will become more important for registering and evaluating evidence followed by summarizing and updating the evidence.

Cardiology↗

PubMed1998

Coronary heart disease risk factors in women.

Despite the obvious predominance of coronary heart disease in middle-aged men, cardiovascular disease including coronary heart disease and cerebrovascular accidents is currently the major cause of death in women (54% cardiovascular mortality, 46% coronary mortality; 28% of all deaths). Before menopause, coronary heart disease is infrequent which suggests that female hormones and metabolism offer protection. Without hormone replacement therapy after menopause women may develop coronary atherosclerosis. Ageing is among the non-modifiable risk factors for coronary heart disease in women, while genetic predisposition and environmental factors remain controversial. The modifiable risk factors are mostly common to both sexes and include heavy cigarette smoking (especially in women under oral contraception) dyslipidaemia, high blood pressure, and diabetes; some factors are peculiar to women. The delayed onset of coronary heart disease in women, roughly 10 years later than in men, and greater feminine longevity (81 years vs 74 in men on average) points to the potential benefit of post-menopause hormone replacement therapy together with reduction of other modifiable risk factors. After menopause, the protective HDL cholesterol decreases whereas high LDL cholesterol, high triglycerides and high blood pressure are major risk factors for coronary heart disease as well as for cerebrovascular accident. The role of hormone replacement therapy in the prevention of cardiovascular disease in women is still controversial despite the results of meta-analyses which suggest a 25% to 44% reduction in coronary heart disease following oestrogen therapy alone or in combination with progestogen, depending on the hormonal regime. In conclusion, menopause, now considered as the marker for the end of natural protection against coronary heart disease, should be followed by early and prolonged combined hormone replacement therapy in order to reduce the low compliance with long-term hormone replacement therapy.

Aging↗

PubMed1998

Do beta-blockers prolong survival in chronic heart failure? A review of the experimental and clinical evidence.

The results of both experimental studies and clinical trials indicate that prolonged activation of the sympathetic nervous system can adversely affect the course of heart failure, and that this deleterious effect can be attenuated with the use of beta-blocking agents. Studies with beta-1 selective agents such as metoprolol and bisoprolol, have demonstrated that beta-blockers can reduce the risk of worsening heart failure but have shown little or equivocal effect on survival. In contrast, recent trials with non-selective vasodilating beta-blockers (i.e. carvedilol) have reported a reduction in the risk of both death and hospitalization. It is uncertain, however, whether these survival effects represent a class effect of beta-blockers or a specific effect of carvedilol. Carvedilol antagonizes several biological mechanisms (not blocked by metoprolol or bisoprolol) that may be important in mediating the progression of heart failure. In three meta-analyses, the survival effects of non-selective vasodilating beta-blockers (primarily carvedilol) were greater than those of beta-1 selective non-vasodilating beta-blockers. A clear answer to the question as to whether mortality reduction is a class effect of beta-blockers will be provided by several large-scale survival trials, which are currently in progress.

Adrenergic beta-Antagonists↗

PubMed1997

Maternal cocaine use and low birth weight newborns: a meta-analysis.

AIM/DESIGN: Many epidemiological studies published on the association between maternal cocaine/crack use and birth weight have either lacked precision or failed to control for major confounding, predominantly by tobacco smoking. Meta-analysis enables a single summary measure of effect to be calculated by combining data from any number of individual studies, thus enhancing statistical power. We undertook a number of meta-analyses using only studies that had adjusted for tobacco smoking to estimate more precisely the effect of maternal cocaine use on birth weight. FINDINGS: A meta-analysis of five studies presenting data for 'any' prenatal cocaine exposure, adjusted for tobacco smoking but unadjusted for gestational age, produced a pooled relative risk estimate from a fixed effects analysis of 2.15 (95% CI 1.75-2.64). However, there was substantial heterogeneity among studies (p < 0.001), and the relative risk from a random effects analysis was smaller (1.65) with a confidence interval that included unity (95% CI 0.94-2.83). Addition of a further study adjusted for gestational age had minimal effect on the pooled estimate: the fixed effects relative risk was 2.14 (1.77-2.60) and the random effects estimate 1.77 (1.15-2.71). When data on more intense prenatal exposure were analysed, the fixed and random effects analysis produced the same pooled estimate of the relative risk of 4.42 (2.24-8.71), suggesting that more frequent cocaine exposure was associated with a higher relative risk for low birth weight. Data from studies on mean reduction in birth weight produced a pooled estimate of 112 g (95% CI 62-161 g). CONCLUSIONS: The current study suggests that maternal cocaine use causes low birth weight, and that the effect is greater with heavier use. However, despite the adjustment for tobacco and the adjustment by some studies for other confounders such as race, maternal age, gravidity and socio-economic status, it could be argued that other life-style factors not controlled for may account for the observed effects. While this argument is not supported by some other types of study, the issue of residual confounding can only be finally addressed by analytical studies which adequately control for important variables.

Cocaine↗

PubMed1997

The relationship between maternal use of heroin and methadone and infant birth weight.

UNLABELLED: AIMS/DESIGN: Reduction in mean birth weight and increased incidence of low birth weight are both associated with exposure to illicit heroin in pregnancy. Many studies examining neonatal outcomes in pregnant heroin users treated with methadone report improvements in birth weight. As a consequence, methadone treatment has become the 'gold standard' for the management of the pregnant heroin user. However, not all studies report significant birth weight increases associated with methadone. We undertook a number of meta-analyses on reduction in mean birth weight and incidence of low birth weight to estimate more precisely the effect of illicit heroin and methadone. FINDINGS: Results showed mean reduction in birth weight associated with heroin use: 489 g (95% CI 284-693 g), compared with methadone: 279 g (229-328 g). Similarly, the pooled relative risk estimate for low birth weight for maternal heroin use was 4.61 (95% CI 2.78-7.65), compared with 1.36 (0.83-2.22) for methadone. Analysis of data on combined heroin and methadone use produced a pooled mean reduction in birth weight of 557 g (403-710 g), with a pooled relative risk estimate for low birth weight of 3.28 (2.47-4.39). Pooling 'any' methadone data, regardless of heroin use, produced an estimated reduction in birth weight of 395 g (311-478 g) and a relative risk estimate for low birth weight of 1.90 (1.29-2.81). Combining all data in an 'any' opiate use analysis also produced a mean reduction in birth weight of 483 g (386-583 g) and a relative risk estimate for low birth weight of 3.81 (2.57-5.65). CONCLUSIONS: The current findings suggest that heroin use while receiving methadone may counteract the birth weight advantage gained from methadone alone. Whether this is due to fetal exposure to heroin plus methadone, to reduced antenatal care, other behavioural and environmental factors associated with concurrent use of heroin and methadone or a combination of these is unclear. Nevertheless, these results challenge the current belief that the pregnant user is always better off receiving methadone than not, and suggests that methadone may not be the appropriate treatment for the pregnant women who continue to use illicit heroin.

Birth Weight↗