Overview of randomised trials of diuretics in pregnancy

Treating hypertension in women of child-bearing age and during pregnancy

Hypertension is found among 1 to 6% of young women. Treatment aims to decrease cardiovascular risk, the magnitude of which is less dependent on the absolute level of blood pressure (BP) than on associated cardiovascular risk factors, hypertension-related target organ damage and/or concomitant disease. Lifestyle modifications are recommended for all hypertensive individuals. The threshold of BP at which antihypertensive therapy should be initiated is based on absolute cardiovascular risk. Most young women are at low risk and not in need of antihypertensive therapy. All antihypertensive agents appear to be equally efficacious; choice depends on personal preference, social circumstances and an agent's effect on cardiovascular risk factors, target organ damage and/or concomitant disease. Although most agents are appropriate for, and tolerated well by, young women, another consideration remains that of pregnancy, 50% of which are unplanned. A clinician must be aware of a woman's method of contraception and the potential of an antihypertensive agent to cause birth defects following inadvertent exposure in early pregnancy. Conversely, if an oral contraceptive is effective and well tolerated, but the woman's BP becomes mildly elevated, continuing the contraceptive and initiating antihypertensive treatment may not be contraindicated, especially if the ability to plan pregnancy is important (e.g. in type 1 diabetes mellitus). No commonly used antihypertensive is known to be teratogenic, although ACE inhibitors and angiotensin receptor antagonists should be discontinued, and any antihypertensive drugs should be continued in pregnancy only if anticipated benefits outweigh potential reproductive risk(s). The hypertensive disorders of pregnancy complicate 5 to 10% of pregnancies and are a leading cause of maternal and perinatal mortality and morbidity. Treatment aims to improve pregnancy outcome. There is consensus that severe maternal hypertension (systolic BP > or = 170mm Hg and/or diastolic BP > or = 110mm Hg) should be treated immediately to avoid maternal stroke, death and, possibly, eclampsia. Parenteral hydralazine may be associated with a higher risk of maternal hypotension, and intravenous labetalol with neonatal bradycardia. There is no consensus as to whether mild-to-moderate hypertension in pregnancy should be treated: the risks of transient severe hypertension, antenatal hospitalisation, proteinuria at delivery and neonatal respiratory distress syndrome may be decreased by therapy, but intrauterine fetal growth may also be impaired, particularly by atenolol. Methyldopa and other beta-blockers have been used most extensively. Reporting bias and the uncertainty of outcomes as defined warrant cautious interpretation of these findings and preclude treatment recommendations.

Effects of pregnancy on specific diseases

Of the numerous physiological changes associated with pregnancy that may have effects on various diseases, the marked increase in blood volume probably exerts the most pronounced effect. This increase may affect the serum level of many medications, as well as affecting various laboratory tests. Other important changes occur in the renal and hepatic system, which in turn may affect the clearance and metabolism of certain drugs and medications. Moreover, the response to and treatment of various diseases during pregnancy may be affected by the "attitude" of the health care providers who are often reluctant to perform certain diagnostic tests and procedures on the pregnant woman.

Survival in patients with intermediate or high grade non-Hodgkin's lymphoma: meta-analysis of randomized studies comparing third generation regimens with CHOP

In patients with intermediate or high grade non-Hodgkin lymphoma (NHL), third generation chemotherapy regimens have been introduced to improve survival in comparison with the standard CHOP regimen. However, most studies have found no difference between these two treatments. We conducted a meta-analysis to assess the effectiveness of third generation regimens as compared with CHOP. Our study included the randomized controlled trials published in English from 1970 to 1999. After a Medline search, 5 trials were found to meet our inclusion criteria. A total of 1982 patients, that were enrolled in these trials, were included in the survival meta-analysis. Our methodology retrieved patient-level information from all of these subjects; survival up to 9 years after randomization was compared between the two treatment options. The results of our meta-analysis showed that, in comparison with CHOP, third generation chemotherapy did not prolong survival at levels of statistical significance (chi-square by log-rank test = 1.44, P = 0.23). The relative death risk for third generation regimens vs. CHOP was 0.92 (95%CI: 0.80 to 1.06;P = 0.26). We conclude that, on the basis of our meta-analysis, third generation regimens do not confer any survival benefit to patients with intermediate or high grade NHL as compared with CHOP.

Effect of diuretics on fetal growth: A drug effect or confounding by indication? Pooled Danish and Scottish cohort data

AIMS

The diabetogenic effect of diuretics, as well as the indication for prescribing them, may impact on fetal growth. We analysed whether the purchase of prescription drugs for diuretics during pregnancy was associated with measures of fetal growth.

METHODS

During 1991-98 all women who purchased prescription drugs for diuretics during pregnancy were identified in the Northern Jutland Prescription Database (NJDP), Denmark, and in the Medicines Monitoring Unit's Database (MEMO), Scotland. Information on birth weight and gestational age was obtained from the Danish Birth Registry, the Danish Hospital Discharge Registry and the Scottish Tayside Neonatal Database. Information on diabetes, hypertension and prepregnancy weight were obtained by hospital record review in a sample of women in the Danish cohort. Women who did not purchase prescription diuretics during pregnancy were used as a reference group in both cohorts.

RESULTS

Danish women who purchased prescription loop diuretics during pregnancy gave birth to infants with higher birth weights than women who did not use diuretics; mean difference 104.7 g (95% CI; 2.6, 206.9). However, the high prevalence of diabetes (10.3%) among Danish women who purchased prescription loop diuretics during pregnancy might explain this result. Both the Danish and the Scottish women who purchased prescription diuretics during their pregnancy were at increased risk of preterm delivery (< 37 completed weeks); ORs: 1.8 (CI; 1.2, 2.7)NJDP, 1.9 (CI; 0.9, 4.3)MEMO. The proportion of hypertension among women who purchased prescription thiazides was 15.8%, and the risk of having an infant with a birth weight (BW) < 2500 g was increased; ORs: 2.6 (CI; 1.4, 5.0)NJDP, 2.4 (CI; 0.8, 7.8)MEMO.

CONCLUSIONS

Prescribing diuretics during pregnancy was associated with differences in birth weight and incidence of preterm delivery. Confounding by indication may explain the findings.

Antihypertensive drug therapy for mild to moderate hypertension during pregnancy

BACKGROUND

Mild-moderate hypertension during pregnancy is common. Antihypertensive drugs are often used in the belief that lowering blood pressure will prevent progression to more severe disease, and thereby improve outcome.

OBJECTIVES

To assess the effects of antihypertensive drug treatments for women with mild to moderate hypertension during pregnancy.

SEARCH STRATEGY

Relevant trials were identified in the register of trials maintained by the Cochrane Pregnancy and Childbirth Group. In addition, the Cochrane Controlled Trial Register, MEDLINE, and EMBASE were searched. Date of last search: October 2000.

SELECTION CRITERIA

All randomised trials evaluating any antihypertensive drug treatment for mild to moderate hypertension during pregnancy, defined whenever possible as systolic blood pressure 140-169 mmHg and diastolic blood pressure 90-109 mmHg. Comparisons were of one or more antihypertensive drug(s) with placebo, with no antihypertensive drug, or with another antihypertensive drug, and where treatment was planned to continue for at least seven days.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers.

MAIN RESULTS

Overall, this review includes 40 studies (3797 women), 24 of which compared an antihypertensive drug with placebo/no antihypertensive drug (2815 women). There is a halving in the risk of developing severe hypertension associated with the use of antihypertensive drug(s) [17 trials, 2155 women; relative risk (RR) 0.52 (95% confidence interval (CI) 0.41 to 0.64); risk difference (RD) -0.09 (-0.12 to -0.06); number needed to treat (NNT) 12 (9 to 17)] but little evidence of a difference in the risk of pre-eclampsia [19 trials, 2402 women; RR 0.99 (0.84 to 1.18)]. Similarly, there is no clear effect on the risk of the baby dying [23 trials, 2727 women; RR 0.71(0.46 to 1.09)], preterm birth [12 trials, 1738 women; RR 0.98 (0.85 to 1.13)], or small for gestational age babies [17 trials, 2159 women; RR 1.13 (0.91 to 1.42)]. There were no clear differences in any other outcomes. Seventeen trials (1182 women) compared one antihypertensive drug with another. There is no clear difference between any of these drugs in the risk of developing severe hypertension, and proteinuria/pre-eclampsia. Other antihypertensive agents seem better than methyldopa for reducing the risk of the baby dying [14 trials, 1010 subjects, RR 0.49 (0.24 to 0.99); RD -0.02 (-0.04 to 0.00); NNT 45 (22 to 1341)]. Other outcomes were only reported by a small proportion of studies, and there were no clear differences.

REVIEWER'S CONCLUSIONS

It remains unclear whether antihypertensive drug therapy for mild-moderate hypertension during pregnancy is worthwhile.

Management of hypertension in pregnancy

Hypertension is an important cause of both maternal and fetal morbidity and mortality in pregnant women. There are still no definitive guidelines as to when and how patients should be treated, but it is important that appropriate treatment is initiated early in patients at highest risk and they are closely monitored. Hypertension in pregnancy can be a difficult condition to diagnose and treat because of the numerous and differing classification systems that have been used in the past. One classification system, which accounts for the multisystem involvement which can occur in pre-eclampsia and eclampsia, divides hypertension in pregnancy into 3 main groups: pre-eclampsia, gestational hypertension and chronic hypertension. Little benefit to the fetus has been shown from treating gestational and chronic hypertension, but studies in this area have been small and would not have had the power to show a difference in outcome between treated and untreated groups. However, the reduction in morbidity and mortality in the treatment of pre-eclampsia is significant. Therefore, all pregnancies complicated by hypertension require monitoring to detect the possible onset of superimposed pre-eclampsia/eclampsia. Institutions should have a management strategy for those mothers with severe hypertension including a multidisciplinary approach, where the patient is to be monitored and which antihypertensive agents are to be used. It should not be forgotten that the definitive treatment for severe hypertension is delivery of the fetus despite risks to fetal morbidity and mortality. This will reduce blood pressure, but hypertension per se may still persist post partum requiring short term therapy.

Bleeding and pneumonia in intensive care patients given ranitidine and sucralfate for prevention of stress ulcer: meta-analysis of randomised controlled trials

OBJECTIVES

To determine the effectiveness of ranitidine and sucralfate in the prevention of stress ulcer in critical patients and to assess if these treatments affect the risk of nosocomial pneumonia.

DESIGN

Published studies retrieved through Medline and other databases. Five meta-analyses evaluated effectiveness in terms of bleeding rates (A: ranitidine v placebo; B: sucralfate v placebo) and infectious complications in terms of incidence of nosocomial pneumonia (C: ranitidine v placebo; D: sucralfate v placebo; E: ranitidine v sucralfate). Trial quality was determined with an empirical ad hoc procedure.

MAIN OUTCOME MEASURES

Rates of clinically important gastrointestinal bleeding and nosocomial pneumonia (compared between the two study arms and expressed with odds ratios specific for individual studies and meta-analytic summary odds ratios).

RESULTS

Meta-analysis A (five studies) comprised 398 patients; meta-analysis C (three studies) comprised 311 patients; meta-analysis D (two studies) comprised 226 patients: and meta-analysis E (eight studies) comprised 1825 patients. Meta-analysis B was not carried out as the literature search selected only one clinical trial. In meta-analysis A ranitidine was found to have the same effectiveness as placebo (odds ratio of bleeding 0.72, 95% confidence interval 0.30 to 1.70, P=0.46). In placebo controlled studies (meta-analyses C and D) ranitidine and sucralfate had no influence on the incidence of nosocomial pneumonia. In comparison with sucralfate, ranitidine significantly increased the incidence of nosocomial pneumonia (meta-analysis E: 1.35, 1.07 to 1.70, P=0.012). The mean quality score in the four analyses (on a 0 to 10 scale) ranged from 5.6 in meta-analysis E to 6.6 in meta-analysis A.

CONCLUSIONS

Ranitidine is ineffective in the prevention of gastrointestinal bleeding in patients in intensive care and might increase the risk of pneumonia. Studies on sucralfate do not provide conclusive results. These findings are based on small numbers of patients, and firm conclusions cannot presently be proposed.

Effects of antihypertensive drugs on the unborn child: what is known, and how should this influence prescribing?

This review discusses the use of antihypertensive drugs in acute and long term treatment of hypertensive disorders of pregnancy, including their placental transfer and adverse effects on the fetus. All antihypertensive agents cross the placental barrier and are present in varying concentrations in the fetal circulation, with varying resultant effects on fetal metabolism. Antihypertensive drugs that are lipid soluble will pass through the placental barrier with ease whereas the most polar will not. Placental transfer diminishes under conditions that decrease the surface area or increase the thickness of the placenta. Highly protein-bound drugs form complexes which impair placental transfer while unbound drugs cross the placenta easily. The ionised drug form is highly charged and cannot cross lipid membranes while the un-ionised form can easily cross the placenta. A decrease in placental blood flow can slow down the transfer of lipid soluble drugs to the fetus. Close monitoring of the fetal and maternal condition is necessary for the rest of the pregnancy after antihypertensive therapy is commenced. Methyldopa is the initial drug of choice for long term oral antihypertensive therapy in pregnancy. Neither short term nor long term use of methyldopa is associated with adverse effects. In the short term (<6 weeks) beta-receptor antagonists are effective and well tolerated provided there are no signs of intrauterine growth impairment. ACE (angiotensin converting enzyme) inhibitors are contraindicated in the second and third trimesters of pregnancy because they are teratogenic. Intravenous dihydralazine is widely used for rapid reductions of severely elevated blood pressure. The use of nifedipine concurrently with MgSO4 must be approached with caution because the combination is associated with severe hypotension, neuromuscular blockade and cardiac depression. In the last decade, knowledge of antihypertensive drugs used in pregnancy has improved and new drugs, e.g. calcium antagonists, which have been shown to have great potential for use in pregnancy, have been introduced. Safety for the fetus with newer drugs has not yet been adequately evaluated. Currently, well established and cost effective drugs such as methyldopa (long term use) and intravenous dihydralazine (rapid reduction) are the agents of choice to treat hypertensive disorders of pregnancy.

Control of error in randomized clinical trials

The randomized clinical trial is the method of choice for comparing the effects of alternative care options, both in its own right and as the cornerstone of systematic reviews of the subject. Errors in such trials, therefore, have major consequences for health care. This paper provides a brief introduction to the major sources of such errors, whether they be systematic or chance errors. It addresses selection bias, due to either biased entry in or biased exclusion from the trial, bias in assessing outcomes, and biases due to contamination or co-intervention. Random errors, including type I and type II errors, are discussed along with ways in which they can be minimized. Small clinical trials, in particular, provide a major problem not only by themselves, but also if they become incorporated in systematic reviews without appropriate consideration of the phenomenon of publication bias.

Chronic hypertension in pregnancy

Pregnancies in women with chronic hypertension are at increased risk of superimposed pre-eclampsia, abruptio placentae, fetal growth retardation and prematurity. The frequencies of these complications are increased in those women who have high-risk chronic hypertension, ie severe hypertension or pre-existing cardiovascular or renal diseases, as well as in those with target organ damage. Such women should receive antihypertensive therapy and close management to improve maternal and fetal outcome. In women with low-risk chronic hypertension, antihypertensive treatments do not improve pregnancy outcome. Prophylactic low-dose acetylsalicylic acid treatment does not reduce the frequency of superimposed pre-eclampsia nor does it improve perinatal outcome in these pregnancies.

1999 World Health Organization-International Society of Hypertension Guidelines for the management of hypertension. Guidelines sub-committee of the World Health Organization

The present Guidelines were prepared by the Guidelines Sub-Committee of the World Health Organization-International Society of Hypertension (WHO-ISH) Mild Hypertension Liaison Committee, the members of which are listed at the end of the text. These guidelines represent the fourth revision of the WHO-ISH Guidelines and were finalised after presentation and discussion at the 7th WHO-ISH Meeting on Hypertension, Fukuoka, Japan, 29th Sept-1st Oct, 1998. Previous versions of the Guidelines were published in Bull WHO 1993, 71:503-517 and J Hypertens 1993, 11:905-918.

Thiazide diuretics in hypertension

Thiazide diuretics have antihypertensive efficacy equivalent to that of the other major classes of antihypertensive drug, and are at least as well tolerated as judged by discontinuation rates and measures of quality of life. They are effective when given once daily, require no dose titration, have few contraindications, and have additive effects when combined with drugs of other classes. The dose-response relation for blood pressure is flat, whereas the subjective and biochemical side-effects are dose-dependent. They should be prescribed only at low dosage. Treatment regimens based on low-dose thiazide prevent stroke, coronary events, heart failure and renal failure in hypertension, and have proven safety. Thiazides are inexpensive. Low-dose thiazides should be preferred for routine first-line treatment of hypertension unless they are contraindicated or there is a compelling indication for an alternative class of drug.

Prevention of preeclampsia

Preeclampsia is a multisystem disorder of unknown cause. Efforts to prevent the disease or reduce its incidence have utilized pharmacological intervention as well as dietary supplementation. Recent, large, randomized trials have not shown a benefit from the use of aspirin. Calcium supplementation has also been studied extensively and found to be similarly ineffective in reducing the incidence or severity of preeclampsia in healthy women. The studies regarding the use of magnesium, zinc, and fish oils for the prevention of preeclampsia are fewer in number, but have also found minimal to no benefit. In the same respect, numerous randomized trials have been performed using antihypertensive agents, diuretics, and low-salt diet. Results of these studies have not shown any beneficial effect. Prevention of preeclampsia is unlikely as long as the underlying origin remains unknown.

Prevention of preeclampsia: a big disappointment

Preeclampsia is a multisystem disorder of unknown etiology. During the past 2 decades, numerous clinical reports and randomized trials described the use of various methods to prevent or reduce the incidence and severity of preeclampsia. These methods were used in an attempt to correct certain abnormalities such as biochemical imbalance, a pathophysiologic mechanism, or a dietary deficiency. There are at least 15 randomized trials evaluating the use of various antihypertensive drugs including diuretics for the prevention of preeclampsia. Results of these trials reveal no such benefit. There are few randomized trials evaluating magnesium (n = 2), zinc (n = 2), or fish oil supplementation (n = 3) to prevent preeclampsia. The majority of these trials had limited sample size; however, results reveal minimal-to-no benefit. There are 7 placebo-controlled trials evaluating calcium supplementation during pregnancy. Findings of these trials reveal that calcium supplementation does not reduce the incidence of preeclampsia in healthy nulliparous women. The majority of randomized trials for the prevention of preeclampsia have used low-dose aspirin. Results of early single-center trials demonstrated an average reduction of preeclampsia of 70% with low-dose aspirin. However, results of recent large multicenter trials (n = 7) that included >27,000 women revealed minimal-to-no benefit. Until the pathogenesis of preeclampsia is well defined, prevention of this syndrome with any modality remains unlikely.

Report of the Canadian Hypertension Society Consensus Conference: 3. Pharmacologic treatment of hypertensive disorders in pregnancy

OBJECTIVE

To provide Canadian physicians with evidence-based guidelines for the pharmacologic treatment of hypertensive disorders in pregnancy.

OPTIONS

No medication, or treatment with antihypertensive or anticonvulsant drugs.

OUTCOMES

Prevention of maternal complications, and prevention of perinatal complications and death.

EVIDENCE

Pertinent articles published from 1962 to September 1996 retrieved from the Pregnancy and Childbirth Module of the Cochrane Database of Systematic Reviews and from MEDLINE; additional articles retrieved through a manual search of bibliographies; and expert opinion. Recommendations were graded according to levels of evidence.

VALUES

Maternal and fetal well-being were equally valued, with the belief that treatment side effects should be minimized.

BENEFITS, HARMS AND COSTS

Reduction in the rate of adverse perinatal outcomes, including death. Potential side effects of antihypertensive drugs include placental hypoperfusion, intrauterine growth retardation and long-term effects on the infant.

RECOMMENDATIONS

A systolic blood pressure greater than 169 mm Hg or a diastolic pressure greater than 109 mm Hg in a pregnant woman should be considered an emergency and pharmacologic treatment with hydralazine, labetalol or nifedipine started. Otherwise, the thresholds at which to start antihypertensive treatment are a systolic pressure of 140 mm Hg or a diastolic pressure of 90 mm Hg in women with gestational hypertension without proteinuria or pre-existing hypertension before 28 weeks' gestation, those with gestational hypertension and proteinuria or symptoms at any time during the pregnancy, those with pre-existing hypertension and underlying conditions or target-organ damage, and those with pre-existing hypertension and superimposed gestational hypertension. The thresholds in other circumstances are a systolic pressure of 150 mm Hg or a diastolic pressure of 95 mm Hg. For nonsevere hypertension, methyldopa is the first-line drug; labetalol, pindolol, oxprenolol and nifedipine are second-line drugs. Fetal distress attributed to placental hypoperfusion is rare, and long-term effects on the infant are unknown. Magnesium sulfate is recommended for the prevention and treatment of seizures.

VALIDATION

The guidelines are more precise but compatible with those from the US and Australia.

Drug management of hypertensive disorders of pregnancy

Drugs used in the acute and long-term management of hypertension in pregnancy and the preeclampsia-eclampsia syndrome have been reviewed and their therapeutic effects and maternal and fetal adverse effects have been considered. The review also focuses on recent developments in the areas of prevention and management of pre-eclampsia-eclampsia syndrome. Although a number of new drugs have emerged, as potentially useful in the management of hypertension in pregnancy and pre-eclampsia-eclampsia syndrome, some remain at the cornerstone of therapy; for example, methyldopa for long-term treatment of chronic hypertension, hydralazine or nifedipine for rapid reduction of severely elevated blood pressure, and magnesium sulphate for eclampsia. Some of these agents, especially the calcium antagonists, show promise in that their use is associated with fewer side effects. Safety for the fetus, however, has not been adequately evaluated yet. Neither aspirin nor calcium supplements appear to improve the outcome in pregnancy. Currently, the dilemma whether to treat hypertension in pregnancy and pre-eclampsia-eclampsia syndrome with old, established, cost-effective drugs or the promising newer drugs provides an interesting academic challenge.

Efficacy of cardiac rehabilitation. 1: A critique of the research

This article, the first of two parts, suggests that cardiac rehabilitation has two primary foci: the reduction of morbidity and mortality, and the amelioration of distress associated with cardiac pathology. While exercise programmes figure prominently in cardiac rehabilitation, empirical studies attest to their relatively modest impact on the recurrence of myocardial infarction. Other interventions such as stress management programmes reduce psychological distress and increase effective coping mechanisms, but only for a limited period. Traditional educational programmes compare unfavourably with cognitive-behavioural interventions. Empirical research appraising the efficacy of many cardiac rehabilitation interventions are tainted by numerous design problems. The second part of this article considers research into the efficacy of smoking cessation and type A behaviour modification programmes.

Development of a tool to rate the quality assessment of randomized controlled trials using a Delphi technique

The aim of this study was to develop a quality of study tool rate the methodological quality of individual primary randomized controlled trials (RCTs) to be included in a meta-analysis. A Delphi-technique using several rounds of questions to seek consensus, among trialists, on criteria important in a RCT was used. Eight trialists formed the Delphi panel. The developed quality of study tool consisted of 53 items in 15 dimensions. The tool was tested for reliability and validity. Unlike many other quality assessment tools, the developed tool may be used to rate numerically each primary study. This is important in reviews or in meta-analyses where one objective may be to ascertain whether those studies of a higher quality exhibit different results to reviewing studies of lower quality. The tool needs further testing.

Treatment of hepatocellular carcinoma: a systematic review of randomized controlled trials

BACKGROUND

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death. Many treatments have been proposed but considerable uncertainty still remains about their effectiveness. In this review we evaluated the quality, clinical coherence, consistency and results of Randomized Controlled Trials (RCT) of non-surgical treatments for HCC.

METHODS

Thirty-seven RCTs examining the effect of different treatments were retrieved using MEDLINE (November 1978 to December 1995) and a review of reference lists. Selected aspects of the quality of design, conduct and reporting were examined. The odds ratio for the probability of surviving up to one year was calculated according to the Mantel Haenszel Peto method and displayed using l'Abbe plots.

RESULTS

The 37 RCTs overall included 2803 patients (median 56, range 20-289). Patients prognosis varied widely across studies which also failed to report on important information about their characteristics. Only 10 RCTs had an untreated control group; the remaining 27 compared different regimens of intravenous or intraarterial chemotherapy with or without embolization of hepatic artery, hormono- and immunotherapy regimens. Some evidence of a moderate benefit emerged only from RCTs using tamoxifen and transcatheter arterial embolization vs. no treatment in unresectable patients: pooled odds ratio for 1-year survival were, respectively, 2.0 (95% confidence intervals (CI) 1.1-3.6) and 2.0 (95% CI 1.1-3.6). At 2 years, however, pooled odds ratio were no longer statistically significant for tamoxifen 1.2 (95% CI 0.6-2.6) but was significant for embolization 2.3 (95% CI 1.2-4.6). No evidence of efficacy was detected for embolization as adjuvant therapy in resected or transplanted patients nor for chemotherapy added to intraarterial embolization.

CONCLUSIONS

This systematic review of RCTs on HCC, mostly in non resectable patients, indicate that the non-surgical current treatments are ineffective or minimally and uncertainly effective. The three treatment modalities minimally and uncertainly effective (i.e., embolization, tamoxifen and IFN) can deserve further assessment by larger and methodologically more sound randomized trials.

Relationship between cathepsin-D content and disease-free survival in node-negative breast cancer patients: a meta-analysis

Several reports have evaluated the correlation between cathepsin-D and overall survival or disease-free survival in node-negative breast cancer patients. Because conflicting data have so far been reported, a meta-analysis was conducted to clarify this problem. Eleven studies were included in our meta-analysis (total of 2690 patients). A specific meta-analytical methodology for censored data was used, and disease-free survival was the primary end point. Patients with low cathepsin-D levels had a significantly better disease-free survival than patients with high cathepsin-D values (meta-analytical odds ratio from 0.59 to 0.60 over the interval from 1 to 7 years). A secondary meta-analysis conducted exclusively on the data from eight studies based on cytosol assay gave substantially similar results. One limitation of our study is that the cut-off values to define high and low cathepsin-D concentrations were not identical in the various studies included in our meta-analysis (range from 20 to 78 pmol mg(-1) protein), thus introducing a possible bias in the statistical analysis of the data. However, a simulation based on the well-accepted method of the so-called publication bias showed that more than 100 null studies would be required to lead our results to a statistical level of non-significance. Considering the results of our meta-analysis, we conclude that the data presently available confirm a statistically significant association between high cathepsin-D values and poor disease-free survival in node-negative breast cancer patients.

Are non-pharmacological nursing interventions for the management of pain effective?--A meta-analysis

A meta-analysis of randomized controlled trials (RCTs) assessing the effectiveness of a non-pharmacological intervention on the management of pain was conducted. Forty-nine relevant primary studies were identified and retrieved. Individual mean pain scores from these studies were converted to standardized effect sizes and meta-analyses were conducted. Although there is evidence, in the form of primary studies, to suggest that non-pharmacological nursing interventions are effective in the management of pain, the 49 studies, pooled in this meta-analysis, were too heterogeneous to detect a difference between the treatment and control groups reliably. There is a need to rigorously test these interventions in the form of primary RCTs.

Meta-analysis of some results of clinical trials on sulodexide therapy in peripheral occlusive arterial disease

The aim was to look at the effect of sulodexide in diabetic and non-diabetic patients with peripheral occlusive arterial disease (POAD), by verifying, through meta-analysis of Italian data, if the drug affects the clinical course of claudication or the main risk factors for POAD. Sulodexide increases the pain-free walking distance (benefit 36% vs controls, P < 0.001). The meta-analysis confirmed the effectiveness of sulodexide in improving claudication (lower limit of the 95% CI for overall odds ratio always > 1). There was a marked effect in lowering triglycerides (overall -28%, P = 0.0015), fibrinogen (-13%, P < 0.0001) and plasma and serum viscosities, and in increasing high-density-lipoprotein cholesterol (24.4%, P = 0.0007). The medium-term administration of sulodexide has a therapeutic effect on claudication of diabetic and/or hyperlipidaemic patients suffering from POAD stages- and also counteracts several POAD risk factors. Long-term use of sulodexide appears to be well tolerated. The treatment has a low daily cost; therefore, it has a favourable cost-benefit ratio, in view of the high general costs associated with global POAD care, particularly in diabetic patients.

Acute myocardial infarction during pregnancy and puerperium: a review

The purpose of this review is to analyze the possible parameters that lead to the development of what is a rare event--acute myocardial infarction (AMI) during pregnancy and puerperium. Through the Index Médicus, 109 publications on the subject were obtained. Since the first well-documented case by Katz in 1922, 136 patients have been reported, and from these reports the following data have been gathered: the average age was 32.1 years. This event is more frequent during the third trimester and puerperium of the first and second pregnancies. In 42.6% of the patients no coronary risk factors were observed, but when present, hypertension and cigarette smoking were the most common. The anterior wall along or in combination with any other anatomic area was affected in 73% of cases. Coronary angiograms, when taken, appeared normal in 47%. The maternal mortality rate was 26/136 (19.1%) and was higher during the third trimester, labor, and puerperium. Eight patients (8/26) (30.7%) had sudden death. In 5 of these, (62.5%) coronary thrombosis was found. In 18/26 deaths, an autopsy was performed; 9/18 (50%) had coronary thrombus formation and in 7/18 (39%) variable degrees of atherosclerosis were detected. On the other hand, the fetal mortality rate was 16.9%; however, in only 52% was death coincidental with that of the mother. Coronary artery spasm associated with a probable hypercoagulability state was the most likely mechanism in the majority of these patients, followed by atherosclerotic heart disease and coronary dissection-the last being secondary most likely to hormonal changes. During the AMI these patients should be studied by a medical team composed of a cardiologist, gynecologist, and anesthesiologist. A complete cardiologic work-up should be made to decide individually about further pregnancies.

G-CSF for the prophylaxis of neutropenic fever in patients with small cell lung cancer receiving myelosuppressive antineoplastic chemotherapy: meta-analysis and pharmacoeconomic evaluation

Standard meta-analytical and pharmacoeconomic techniques were used to study the clinical effectiveness and the cost-effectiveness ratio of the prophylactic (or pre-emptive) administration of G-CSF to patients with small cell lung cancer treated with conventional myelosuppressive cytotoxic chemotherapy. In the first part of our study, we conducted a meta-analysis of the randomized clinical trials evaluating G-CSF for this clinical indication. Three trials were identified by our literature search and were included in the meta-analysis (overall number of patients = 606). The end-points for evaluating G-CSF included mortality from infection and the cumulative incidence of neutropenic fever over six cycles of chemotherapy. The results of our meta-analysis demonstrate that prophylactic G-CSF did not affect mortality but significantly reduced the incidence of neutropenic fever from 68.3% to 38.7% (pooled odds ratio = 0.29, 95% CI: 0.21-0.40; P < 0.001). In the second part of our study, we carried out a pharmacoeconomic analysis to estimate the cost-effectiveness ratio of pre-emptive G-CSF (i.e. the 'average' cost associated with the prevention of an episode of neutropenic fever). This cost-effectiveness ratio was US$ 14,372 using the Italian price of the drug converted into dollars, or US$ 41 088 using the US price. Finally, we estimated the revenue-neutral price of G-CSF based on American data of the cost-of-illness. The price ranged from US$ 395 to US$ 569 per cycle, a figure higher than the value (US$ 150) previously reported in the literature.

Defined-formula diets versus steroids in the treatment of active Crohn's disease: a meta-analysis

BACKGROUND

To compare the effectiveness of defined-formula diets versus steroids for the treatment of active Crohn's disease, we conducted a meta-analysis of the published clinical trials.

METHODS

Standard techniques for literature search were used to identify the pertinent trials. All studies included in our meta-analysis (n = 7) were aimed at comparing defined-formula diets versus steroids, using a randomized design. The patient-specific end-point of the meta-analysis was the occurrence of a treatment failure.

RESULTS

Our meta-analysis indicated that steroids are more effective than defined-formula diets for inducing remission in active Crohn's disease. In fact, the relative risk of treatment failure (RTF) was significantly lower in the steroid group than in the diet group (risk values for patients given steroids compared with patients given diet: a) method of Mantel-Haenszel: RTF = 0.35; 95% confidence interval, 0.23-0.53; p < 0.001; b) method of Der Simonian & Laird: RTF = 0.43; 95% confidence interval, <0-0.94; p = 0.03). A separate analysis was carried out in which only the subgroup of patients who were not intolerant to diet were evaluated; this analysis also showed a superiority of steroids over diet.

CONCLUSIONS

The data examined in this meta-analysis do not support the use of diets as primary treatment for acute exacerbations of Crohn's disease in adults.

Cholecystectomy as a risk factor for colorectal cancer: a meta-analysis

BACKGROUND

It has been suggested that there is an increased risk of colorectal cancer after cholecystectomy due to increased levels of secondary bile acids. Some studies suggest the risk is higher for women and for the development of right-sided tumours.

METHODS

A review of the literature yielded 95 relevant studies, of which 35 were suitable for a meta-analysis involving age- and sex-matched controls.

RESULTS

The pooled odds ratio for a positive association between cholecystectomy and colorectal cancer was 1.11 (95% confidence interval (CI), 1.02 to 1.21). For women the odds ratio was 1.14 (95 % CI, 10.01 to 1.28) and for right-sided cancer 1.86 (95% CI, 1.31 to 2.65).

CONCLUSIONS

It is possible that this small observed association may be due to a publication bias for positive results or bias within the included studies. If it is indeed a real effect, the risk to an individual is very small.

How effective is enteral nutrition in inducing clinical remission in active Crohn's disease? A meta-analysis of the randomized clinical trials

BACKGROUND

The purpose of the study was to evaluate, using meta-analysis techniques, whether enteral nutrition is effective in inducing clinical remission in active Crohn's disease.

METHODS

Randomized trials either comparing enteral nutrition with steroids or comparing elemental (amino acid-based) with nonelemental diets were selected using MEDLINE (1984 to 1994), reference lists from published articles, reviews, and abstracts from major gastrointestinal meetings. Sixteen studies fulfilled the inclusion criteria (four published as abstracts). Crude rates for induction of remission were collected on an intention-to-treat basis by three independent observers. Each study was given a quality score, based on predetermined criteria.

RESULTS

The pooled odds ratio (OR) for all type of enteral diets compared with steroid therapy was 0.35 (95% CI, 0.23 to 0.53). This result was similar for the best studies (by quality score) combined, for trials using tube feeding combined, and when noncompliant patients were withdrawn. Further subgroup analyses were conducted on the basis of the type of diet administered. Peptide-based diets were significantly inferior to steroids (pooled OR, 0.32; CI, 0.20 to 0.52). There was a trend to lower remission rate after elemental diets than after steroids (pooled OR, 0.44; CI 0.17 to 1.12). On the other hand, pooled OR for whole protein-based diets compared with elemental diets was 1.28 (CI, 0.40 to 4.02).

CONCLUSIONS

Data available to date show that steroids are better than enteral nutrition to induce remission in active Crohn's disease. These results are more evident when peptide-based diets are administered, but they are not conclusive when either elemental or whole protein-based diets are used.

Nephrolithiasis in pregnancy

Although the anatomical and physiological changes of normal pregnancy may predispose to kidney stone formation, it remains an uncommon occurrence. Correct diagnosis is often difficult. Ultrasonography has become the primary radiological diagnostic tool, with a limited excretory urogram only necessary in complicated cases. Nephrolithiasis during pregnancy occurs more frequently during the later stages of gestation, in multiparas, and without a difference in laterality. Conservative management with bed rest, hydration and analgesia can result in spontaneous passage of most stones in gravidas. Past experience of several groups suggests that cystoscopy and/or surgery can usually be done safely when absolutely necessary. Pre-existing stone disease can increase the incidence of maternal urinary tract infections by 10-20%. The most common obstetric complications of stones during gestation is premature labour induced by renal colic. Most drugs normally used to treat stone disease are contraindicated in gestation. Known inhibitors of stone formation are present in gestation and may partially explain why the incidence of stones is not increased in this hypercalciuric state.

Hypertension in pregnancy

From the clinical point of view proteinuric hypertension or preeclampsia is the most important form of hypertension in pregnancy and carries the greatest risks for mother and foetus. The syndrome 'preeclampsia' differs from other types of hypertension and its effects on mother and foetus are not clearly benefited by lowering the blood pressure with drugs. The characteristic morphological changes and altered vascular reactivity which develop in preeclampsia commence at about 14 weeks gestation, long before hypertension or proteinuria appear. Many abnormalities in coagulation mechanisms appear in preeclampsia and some may play an important part in pathogenesis. Increased plasminogen activator inhibitor may play a key role. Antihypertensive drugs used during pregnancy may reduce foetal mortality and the incidence of preeclampsia. Calcium supplementation and aspirin may reduce the incidence of preeclampsia in high risk subjects. Heparin and dipyridamole may reduce the risk of preeclampsia in high risk patients with renal disease.

The possible role of intravenous immunoglobulin in preventing pre-eclampsia

Our understanding of the pathophysiologic abnormalities contributing to pre-eclampsia has increased substantially over the past decade. This has been accompanied by the introduction of various methods which reduce the incidence of pre-eclampsia to approximately the same range (4-11.8% in high risk group), by attempting to correct the pathophysiologic abnormalities involved, rather than averting its occurrence. Numerous reports suggest that pre-eclampsia is caused by an abnormal maternal immune response to antigenic challenge by the fetoplacental allograft. If this assumption is true, it may be possible to manipulate the maternal immune response to fetal allograft and to assist the immunologic homeostasis of the maternal host with her conceptus by passive immunization with intravenous immunoglobulins (IVIg) and thus, to prevent pre-eclampsia. Recently IV preparations of Ig have become available for clinical use including treatment of various immunologic disorders during pregnancy. The effectiveness of this new mode of therapy can be related to several immunological mechanisms such as blockade of antibody binding to receptors on macrophages, increase in T suppressor cells, or decrease in antibody synthesis. The latter effect may be mediated by anti-idiotypic antibodies in the Ig preparation, which may bind to idiotypes on pathogenic autoantibodies and neutralise their activity.

Controversies in meta-analysis: the case of the trials of serum cholesterol reduction

There has recently been disagreement in the literature on the results and interpretation of meta-analyses of the trials of serum cholesterol reduction, both in terms of the quantification of the effect on ischaemic heart disease and as regards the evidence of any adverse effect on other causes of death. This paper describes statistical aspects of a recent meta-analysis of these trials, and draws some more general conclusions about the methods used in meta-analysis. Tests of an overall null hypothesis are shown to have a basis clearly distinct from the more extensive assumptions needed to provide an overall estimate of effect. The fixed effect approach to estimation relies on the implausible assumption of homogeneity of treatment effects across the trials, and is therefore likely to yield confidence intervals which are too narrow and conclusions which are too dogmatic. However the conventional random effects method relies on its own set of unrealistic assumptions, and cannot be regarded as a robust solution to the problem of statistical heterogeneity. The random effects method is more usefully regarded as a type of sensitivity analysis in which the weights allocated to each study in estimating the overall effect are modified. However, rather than using a statistical model for the 'unexplained' heterogeneity, greater insight and scientific understanding of the results of a set of trials may be obtained by a careful exploration of potential sources of heterogeneity. In the context of the cholesterol trials, the heterogeneity according to the extent and duration of cholesterol reduction are of prime concern and are investigated using logistic regression. It is concluded that the long-term benefits of serum cholesterol reduction on the risk of heart disease have been seriously underestimated in some previous meta-analyses, while the evidence for adverse effects on other causes of death have been misleadingly exaggerated.

Hypertension in pregnancy

High blood pressure, which complicates approximately 10% of all pregnancies, remains a major cause of morbidity and mortality for both mother and fetus. A relative paucity of investigative data, as well as the frequent difficulty in making an etiological diagnosis by clinical criteria alone, may be among the reasons why there are many conflicts about the management of hypertension during pregnancy. This clinical conference summarizes current concepts regarding the hypertensive disorders of gestation, focusing on the most dangerous cause, preeclampsia-eclampsia. It further highlights a recent report of the Working Group on High Blood Pressure in Pregnancy convened by the National High Blood Pressure Education Program at the National Heart, Lung, and Blood Institute (the Consensus Report). Among the Working Group's most interesting recommendations in controversial areas were a return to the classification schema suggested by the American College of Obstetricians and Gynecologists in 1972, use of the fifth Korotkoff sound to determine diastolic blood pressure levels, and institution of treatment with antihypertensive drugs for sudden elevations of blood pressure near term to diastolic levels greater than or equal to 105 mm Hg or for levels of 100 mm Hg or higher in pregnant women with chronic hypertension. The Consensus Report further recommended parenteral hydralazine and methyldopa as the drugs of choice for the acute hypertensive crisis and management of chronic hypertension, respectively, based on the long histories of safe use of these agents in gravidas. Parenteral magnesium sulfate remained the preferred therapeutic approach for avoiding or treating the convulsive complication, eclampsia, but the Working Group underscored the need for controlled trials of magnesium's efficacy. Finally, they noted that diuretics should be avoided in preeclampsia, but that these drugs can be continued during gestation if taken before conception, and may be prescribed to pregnant women with chronic hypertension who appear overly salt sensitive.

Distal spleno-renal shunt versus endoscopic sclerotherapy in the prevention of variceal rebleeding. A meta-analysis of 4 randomized clinical trials

Meta-analysis was used to evaluate 4 clinical trials comparing distal spleno-renal shunt (DSRS) with endoscopic sclerotherapy (EVS) in the prevention of variceal rebleeding: the interval between bleeding and therapy ranges from < 14 days to > 100 days. A questionnaire was sent to each author of the published trials concerning methods, definitions and results of the trials in order to obtain more detailed and up-to-date information. The selected end-points for the meta-analysis were: rebleeding, mortality and chronic encephalopathy. Analysis of the results in the questionnaires was made using the method proposed by Collins. The pooled relative risk (i.e. the combined Odds ratio of each trial as an estimate of overall efficacy) of rebleeding was statistically reduced by DSRS (0.16; 95% confidence interval 0.10-0.27). Despite this, the overall risk of death following DSRS was only marginally decreased (0.78; 95% confidence interval 0.47-1.29); the lack of homogeneity in the results does not permit any significant conclusions on this end-point. However, in non-alcoholic patients, the decrease in risk of death was greater, and this without heterogeneity, following DSRS than EVS (0.59; 95% confidence interval 0.23-1.50). The overall risk of chronic encephalopathy was slightly increased after DSRS (1.86; 95% confidence interval 0.90-3.86). In conclusion, DSRS significantly reduced the risk of rebleeding compared to EVS without increasing the risk of chronic hepatic encephalopathy. However, DSRS did not significantly affect the overall death risk. Only in non-alcoholic disease did it seem to show an advantage over EVS.

The role of portosystemic shunting in the management of portal hypertension

In this chapter, we have tried to indicate the role of the portosystemic shunt in the treatment of portal hypertension. The conclusions are evident: in the last 10 years it has lost its role as leader in the treatment of portal hypertension. However, some firm statements can be made. The selective shunt is an operation that provides both good variceal decompression and satisfactory maintenance of liver function. Its results in great part depend on the skill of the surgeon. Only a patient with good liver function (Child's classes A and B) is a candidate for shunt surgery, with, very occasionally, a patient with severe disease (class C). In an emergency, the operation is used only after failure of sclerotherapy, but it must be used at the right time before the patient's condition has deteriorated. In the prevention of variceal rebleeding, the selective shunt or sclerotherapy can be routine measures. The choice between the two treatments depends on the patient's willingness and the ability of the institution to perform both procedures successfully. If sclerotherapy is chosen, the institution must be able to rapidly rescue a sclerotherapy failure by shunt surgery. Liver transplantation is probably the treatment of the future, but it is at present impossible to suggest that the procedure is feasible for all patients with variceal bleeding and severe liver disease.