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[Evaluation of the efficacy of a comprehensive programme of secondary prevention of cardiovascular disease in primary care: the PREseAP Study].

OBJECTIVES: To assess the efficacy of a comprehensive secondary prevention programme to reduce morbidity and mortality in patients who have suffered a cardiovascular (CV) event; to control CV risk factors and prophylactic treatment in order to prevent recurrence; and to improve the quality of life of patients with cardiovascular disease. DESIGN: Randomised, pragmatic, open clinical trial in primary care. SETTING: A total of 42 primary care centres of 8 different areas in Spain. PARTICIPANTS: Men and women below 86 years old, diagnosed with coronary disease and/or stroke and/or peripheral vascular disease in the preceding year, and who have no serious or terminal disease. INTERVENTION: Primary care centres will be randomised to following usual care (control group), or to following a comprehensive programme of secondary prevention (intervention group). MAIN MEASUREMENTS: Cardiovascular fatal events, cardiovascular non-fatal events, total mortality and health-related quality of life (SF-36).

Adult↗

Surgical versus conservative treatment for acute injuries of the lateral ligament complex of the ankle in adults.

BACKGROUND: Inversion injuries, primarily sprains, of the ankle are one of the most commonly treated injuries. The three main treatment modalities for acute lateral ankle ligament injuries are immobilisation with plaster cast or splint, 'functional treatment' comprising early mobilisation and the use of an external support (e.g. ankle brace or taping), and surgical repair or reconstruction. OBJECTIVES: We aimed to compare surgical versus conservative treatment for acute injuries of the lateral ligament complex of the ankle in adults. SEARCH STRATEGY: We searched the Cochrane Musculoskeletal Injuries Group specialised register (December 2001), the Cochrane Controlled Trials Register (The Cochrane Library, Issue 4, 2001), MEDLINE (1966 to May 2000), EMBASE (1980 to May 2000), CURRENT CONTENTS (1993 to 1999), BIOSIS (to 1999), reference lists of articles, and contacted organisations and researchers in the field. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials comparing surgical with conservative interventions for treating acute injuries to the lateral ligament complex of the ankle in adults. DATA COLLECTION AND ANALYSIS: At least two, usually three, reviewers independently assessed methodological quality and extracted data. Where appropriate, results of comparable studies were pooled using fixed and random effects models and relative risks with 95% confidence intervals for dichotomous outcomes calculated. Heterogeneity between trials was tested using a standard chi-squared test. We undertook sensitivity analyses to explore the effects of inclusion of quasi-randomised trials and subgroup analyses by the two main methods of conservative treatment. MAIN RESULTS: Seventeen studies, involving a total of 1950 mostly young active adult males, were included. All trials had methodological flaws. In particular, allocation was rated as effectively concealed in only one trial and there was no report of masking outcome assessors to the interventions in any trial. Outcome measures were variously defined and data for pooling for individual outcomes were only available for a maximum of 11 studies. While there were statistically significant differences for three primary outcomes (non-return to pre-injury level of sports; undefined pain or pain on activity; and subjective or functional instability) in favour of the surgical treatment group using the fixed effects model, these findings failed to demonstrate robustness in sensitivity analyses. Exclusion of the data from explicitly quasi-randomised trials or, given the highly statistically significant heterogeneity, analyses using the random effects model modified these findings to non-statistically significant differences. There was no statistically significant difference in ankle sprain recurrence, the other primary outcome measure. Though there was a statistically significantly higher incidence of objective instability in conservatively treated patients, the functional implications of this are uncertain. There was some evidence for a lower incidence of long-term ankle swelling in surgically treated patients. However, as well as tending to take longer to resume normal activities, including work, there was some limited evidence from a few trials for a higher incidence of ankle stiffness, impaired ankle mobility and complications in the surgical treatment group. Subgroup analyses by type of conservative treatment (plaster cast or functional treatment) revealed no statistically significant differences in effect for any of the six outcomes examined. REVIEWER'S CONCLUSIONS: There is insufficient evidence available from randomised controlled trials to determine the relative effectiveness of surgical and conservative treatment for acute injuries of the lateral ligament complex of the ankle. Sufficiently powered, good quality and adequately reported randomised trials of primary surgical repair versus the best available conservative treatment for well-defined injuries are required.

Acute Disease↗

Lessons learned from randomised clinical trials in adult low grade glioma.

"Lesson" is a Middle English word that has been defined as "a passage from sacred writings read in a service of worship" as well as "something learned by study or experience". The term is quite appropriate in assessment of what has been learned from randomised trials in adult low-grade gliomas, since the treatment of these tumours has traditionally been guided as much by belief as by fact. Therefore, when assessing these trials we can apply the principles of hermeneutics. Thus, the first meaning of "lesson" given here can be described as literal, whereas the second may be seen as figurative. Since hermeneutics may also refer to an in-depth analysis of a particular text, the investigators will present their interpretation of data from randomised trials. The goal is to show that the lessons learned are not necessarily literal or dogmatic but can be much more allegorical in nature.

Adult↗

[Stem cell transplantation in germ cell tumors].

High dose chemotherapy (HDCT) with autologous stem cell transplantation in patients with relapsed or refractory non-seminomatous germ cell tumors seems to be the only therapeutic option with curative intention. Evaluation of a scored risk profile before HDCT might significantly support the precise estimation of results after HDCT. Patients with a negative or low score could achieve long-lasting complete remissions or might be cured, whereas patients with absolutely refractory disease do not benefit from HDCT. Ongoing prospective randomised trials in Europe and USA comparing standard therapy with HDCT will hopefully contribute to the right therapeutic decision in the future.

Antineoplastic Combined Chemotherapy Protocols↗

Drug treatment for faecal incontinence in adults.

BACKGROUND: Faecal incontinence is a common symptom which causes significant distress and reduction in quality of life. Available treatment options for faecal incontinence include conservative treatments (biofeedback, pelvic floor muscle training, dietary manipulation or drug therapy) or surgical treatments (e.g. sphincter repair, post anal repair, neosphincter). Drug treatment is often given either alone or in combination with other treatment modalities. OBJECTIVES: To assess the effects of drug therapy for the treatment of faecal incontinence. In particular, to assess the effects of individual drugs relative to placebo or other drugs, and to compare drug therapy with other treatment modalities. SEARCH STRATEGY: We searched the Cochrane Incontinence Group trials register (January 2003) and the reference lists of relevant articles. Date of the most recent search: January 2003. SELECTION CRITERIA: All randomised or quasi-randomised controlled trials of the use of pharmacological agents for the treatment of faecal incontinence in adults. DATA COLLECTION AND ANALYSIS: Working independently, reviewers selected studies from the literature, assessed the methodological quality of each trial, and extracted data. MAIN RESULTS: Eleven trials were identified for inclusion in this review. Nine trials were of cross-over design. Seven trials included only people with faecal incontinence related to liquid stool (either chronic diarrhoea or following ileoanal pouch surgery). Three trials (total 58 participants) compared topical phenylephrine gel with placebo. Two trials (56 participants) compared loperamide with placebo. One trial (11 participants) compared loperamide oxide with placebo. One trial (15 participants) compared diphenoxylate plus atropine with placebo. One trial (17 participants) compared sodium valproate with placebo. One trial (30 participants) compared loperamide with codeine with diphenoxylate plus atropine. Two further trials (total 265 participants) assessed the use of lactulose in elderly people.No studies comparing drugs with other treatment modalities were identified. There was limited evidence that antidiarrhoeal drugs and drugs which enhance anal sphincter tone may reduce faecal incontinence in patients with liquid stools. However, the trials were small and of short duration. REVIEWER'S CONCLUSIONS: The small number of trials identified for this review assessed several different drugs in a variety of patient populations. The focus of most of the included trials was on the treatment of diarrhoea, rather than faecal incontinence. There is little evidence to guide clinicians in the selection of drug therapies for faecal incontinence. Larger, well-designed controlled trials, which include clinically important outcome measures, are required.

Adult↗

In-hospital care pathways for stroke.

BACKGROUND: Care within a stroke unit reduces death or dependency after stroke. However, studies have found significant variations in clinical practice, access to stroke unit care, organisation of patient care, and clinical outcome. Stroke care pathways have been introduced as a method to promote organised and efficient patient care that is based on best evidence and guidelines. OBJECTIVES: We aimed to assess the effects of care pathways, as compared to standard medical care, among patients with acute stroke who had been admitted to hospital. SEARCH STRATEGY: We searched the Cochrane Stroke Group Specialised Trials Register (last searched in May 2001), the Cochrane Controlled Trials Register (Issue 4, 2000), MEDLINE (1975-2000), EMBASE (1980-2000), CINAHL (1982-2000), the Index to Scientific and Technical Proceedings (ISTP, May 2001), and HealthSTAR (May 2001). We also handsearched the Journal of Managed Care (1997 to 1998), which was later renamed the Journal of Integrated Care (1998 to 2001). Reference lists of articles were searched. SELECTION CRITERIA: We considered randomised controlled trials and non-randomised studies (quasi-randomised trials, comparative studies, controlled and uncontrolled before and after studies, and interrupted time series) that compared care pathway care with standard medical care. DATA COLLECTION AND ANALYSIS: One reviewer selected studies for inclusion and the other independently checked the decisions. Two reviewers independently assessed the methodological quality of the studies. One reviewer extracted the data and the other checked the extracted data. Data from randomised and non-randomised studies were analysed separately. We found significant statistical heterogeneity in the analysis of two outcomes (computed tomography brain scanning and duration of stay). MAIN RESULTS: There were three randomised controlled trials (total of 340 patients) and seven non-randomised studies (total of 1673 patients) that compared care pathway care with standard medical care. We found no difference between care pathway and control groups in terms of death, dependency, or discharge destination. Evidence from mainly non-randomised studies suggests that patients managed using a care pathway may be: a) less likely to suffer a urinary tract infection (OR 0.38, CI 0.18 to 0.79), b) less likely to be readmitted (OR 0.11, CI 0.03 to 0.39), and c) more likely to have a computed tomography brain scan (OR 3.66, CI 1.45 to 9.27) or carotid duplex study (OR 2.45, CI 1.3 to 4.61). Evidence from randomised trials suggests that patient satisfaction and quality of life may be significantly lower in the care pathway group (P=0.02 and P<0.005 respectively). REVIEWER'S CONCLUSIONS: The use of care pathways to manage stroke patients in hospital may be associated with both positive and negative effects on the process of care and clinical outcomes. Since most of the results have been derived from non-randomised studies, they are likely to be influenced by potential biases and confounding factors. There is currently insufficient supporting evidence to justify routine implementation of care pathways for acute stroke management or stroke rehabilitation.

Critical Pathways↗

Face washing promotion for preventing active trachoma.

BACKGROUND: Trachoma remains a major cause of avoidable blindness among underprivileged populations in many developing countries. It is estimated that about 146 million people have active trachoma and nearly six million people are blind due to complications associated with repeat infections. OBJECTIVES: The objective of this review is to assess the effects of face washing on the prevalence of active trachoma in endemic communities. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group trials register) on The Cochrane Library (Issue 2, 2004), MEDLINE (1966 to February 2004), EMBASE (1980 to February 2004), the reference lists of identified trials and the Science Citation Index. We also contacted investigators and experts in the field to identify additional trials. SELECTION CRITERIA: We included randomised or quasi-randomised controlled trials, comparing face washing with no treatment or face washing combined with antibiotics against antibiotics alone. Participants in the trials were people normally resident in endemic trachoma communities. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed trial quality. Study authors were contacted for additional information. Two clinically heterogeneous trials are included, therefore a meta-analysis was considered inappropriate. MAIN RESULTS: This review includes two trials with data from a total of 2560 participants. Face washing combined with topical tetracycline was compared to topical tetracycline alone in three pairs of villages in one trial. The trial found a statistically significant effect for face washing combined with topical tetracycline in reducing 'severe' active trachoma compared to topical tetracycline alone. No statistically significant difference was observed between the intervention and control villages in reducing ('non-severe') active trachoma. The prevalence of clean faces was higher in the intervention villages than the control villages and this was statistically significant. Another trial compared eye washing to no treatment or to topical tetracycline alone or to a combination of eye washing and tetracycline drops in children with follicular trachoma. The trial found no statistically significant benefit of eye washing alone or in combination with tetracycline eye drops in reducing follicular trachoma amongst children with follicular trachoma. REVIEWERS' CONCLUSIONS: There is some evidence that face washing combined with topical tetracycline can be effective in reducing severe trachoma and in increasing the prevalence of clean faces. Current evidence does not however support a beneficial effect of face washing alone or in combination with topical tetracycline in reducing active trachoma.

Anti-Bacterial Agents↗

Development of antischistosomal drugs in China, with particular consideration to praziquantel and the artemisinins.

Remarkable achievements have been made in the control of schistosomiasis in China, with chemotherapy playing a seminal role. From the early 1950s through the early 1980s, Chinese scientists made considerable progress in discovery and development of compounds with antischistosomal properties, including antimonials, non-antimonials and various effective principles stemming from traditional herbs. However, only few compounds entered clinical testing, while others were abandoned mainly due to their toxicity and poor efficacy. The advent of praziquantel in the 1970s changed the landscape of research and development of drugs for treatment and morbidity control of schistosomiasis. The main Chinese contributions to enhance the understanding of the antischistosomal drug praziquantel are reviewed here, including issues of metabolism, antibody-dependency, host immune factors, stage-specific susceptibility and resistance. Over the past 25 years, researchers from China successfully developed artemether and artesunate, two derivatives from the antimalarial artemisinin, as promising drugs against Schistosoma japonicum. Laboratory investigations showed that the artemisinins display their highest activity against the juvenile stages of the parasite. These findings were consistently confirmed in randomised controlled trials; repeated oral administration of artemether or artesunate was safe and efficacious in the prevention of patent S. japonicum infections. The key findings are reviewed here, and emphasis is placed on how it stimulated research outside of China on other human schistosome species.

Animals↗

Growth hormone therapy in heart failure: a novel therapy worthy of further consideration?

Despite the improvements in survival with angiotensin-converting enzyme inhibitors and beta-blockers, the clinical events for patients with heart failure remain elevated. New therapies for heart failure are required to improve the functional capacity, quality of life and prognosis. Growth hormone exerts both direct and indirect effects on cardiac structure and function. Experimental models of heart failure and small studies have demonstrated significant improvements in cardiac function, haemodynamical parameters, functional capacity and quality of life. The results from randomised controlled studies have been mixed with others showing benefit and some that do not. The randomised studies showing benefit consistently used growth hormone every other day. Further studies are needed to assess the potential role of this adjuvant therapy in patients with heart failure.

Adjuvants, Pharmaceutic↗

[Interactions between radiation and hormonal therapy in breast cancer: simultaneous or sequential treatment].

BACKGROUND: Combining radiation and hormone therapy (administration of selective estrogen receptor modulators) has become common clinical practice in recent years for receptor positive breast cancer. Little is known about a possible interaction of both treatment modalities if they are given simultaneously. Tamoxifen (antiestrogen molecule, triphenylethylene derivative) may theoretically render cancer cells less responsive to radiotherapy arresting hormone-receptor-positive cells in G0/G1 phase and increase the risk of breast and lung fibrosis stimulating the secretion of transforming growth factor beta in human fibroblasts. PURPOSE: This article reviews the published data to assess the impact of sequencing of hormonal and radiation therapy on outcomes in breast cancer. METHODS: Computerised searches for publications debating the sequencing of hormonal therapy relative to radiation therapy were done using MEDLINE data. RESULTS: Results of tamoxifen experiments with cell culture regarding radioprotection of tumour clonogens are conflicting. In contrast to in vitro results, in animal studies no protective effect of tamoxifen was observed. In one in vitro study, letrozole (non-steroid selective aromatase inhibitor) had a radiosensitizing effect on breast-cancer lines. No randomised clinical trials to date have studied sequencing of tamoxifen or other selective estrogen receptor modulators and radiotherapy. Results from retrospective clinical studies which included treatment arms with and without tamoxifen showed reduction in tumour recurrence with tamoxifen. Some of these studies have noted increased risk of lung and breast fibrosis with tamoxifen with radiotherapy. Results of three articles examined the effect of tamoxifen sequence showed no adverse effect on local control or survival in sequential versus concurrent tamoxifen and radiation patients. One of the three studies also assessed the risk of complications with respect to the timing of tamoxifen with radiotherapy. There was no difference in the rates of complications between the two groups. The association of radiation and selective aromatase inhibitors or aromatase inactivators has not been addressed in clinical studies. CONCLUSIONS: Combined application of tamoxifen and radiotherapy improves survival and local control in breast cancer. Available clinical studies do not indicate that the simultaneous application of tamoxifen and radiotherapy is disadvantageous, as was suggested by some of the in vitro studies. The risk of subcutaneous breast and lung fibrosis might be slightly increased if tamoxifen is given simultaneously with radiotherapy. Both treatment modalities should be started early after surgery. There is no sufficient evidence to withhold tamoxifen administration during irradiation of breast cancer. The issue of optimal sequencing of hormonal and radiotherapy should be addressed in randomised clinical trials.

Animals↗

[Hormonal supplements for postmenopausal women: no evidence of protection against cardiovascular disease].

Atherothrombotic cardiovascular disease is a leading cause of death in women, especially in the postmenopause. It is controversial whether postmenopausal hormone replacement therapy is protective with regard to cardiovascular disease. On the one hand, observational studies consistently show that the risk of cardiovascular disease is 35 to 50% lower among users of hormonal replacement than among non-users. In addition, hormonal replacement is associated with an improvement of the lipid profile and several other potentially beneficial effects. On the other hand, two recent placebo-controlled randomised trials did not find evidence in favour of cardiovascular protection by hormonal replacement. This discrepancy may be explained by insufficient adjustment for lifestyle factors in observational studies and insufficient consideration of methodological flaws in experimental studies, both of which lead to an overestimation of the protective effect of hormonal replacement. Hormonal replacement may affect the pathophysiology of atherothrombosis in several ways, both positive and negative. Progress in this field requires the isolation of the positive effects.

Aged↗

Field efficacy of a 10 per cent pyriproxyfen spot-on for the prevention of flea infestations on cats.

The clinical application of a new method for using the insect growth regulator, pyriproxyfen, for controlling flea populations in cat-owning homes is evaluated for the first time. In a multicentric, controlled and randomised trial, 107 flea-infested cats were treated with a minimum dose of 10 mg/kg bodyweight pyriproxyfen as a 10 per cent spot-on application on two occasions, with a three-month interval between doses. For comparison, 99 cats received lufenuron suspension orally, once a month, for six months. Flea counts decreased significantly over time in each group and were significantly lower in the pyriproxyfen group than in cats treated with the reference product. The percentage of 'zero-flea' cats increased from 49 per cent on day 30 to 88 per cent on day 180 in the pyriproxyfen group and from 30 to 71 per cent in the lufenuron group at the same time points (P<0.05). Appropriately timed topical applications of pyriproxyfen, therefore, offer a method of flea control in the domestic environment.

Administration, Cutaneous↗

[Chemoradiotherapy and anal canal cancer].

Local control and sphincter preservation are the two challenges of anal canal cancer treatment. These tumors are radio- and chemo-sensitive and treatment moved from surgical approach, with abdominoperineal resection, to definitive radiation therapy with or without concurrent chemotherapy. Randomised trials proved the benefit of combined modality with chemoradiotherapy and of mitomycine C (MMC) compared with radiotherapy alone, with a toxic death rate of about 2%. Indications of chemoradiotherapy are locally advanced tumor T2 > or = 4 cm, T3-4 or N1-3 but the best modalities of combined treatment are still under debate. Standard chemotherapy is 5 flurouracile (5FU) + MMC, but cisplatinum (CDDP) is an effective and well tolerated substitute for MMC. Favourable results with CDDP-containing regimen in term of toxicity and carcinologic control have been reported in phase II and retrospective studies. Total radiation dose, overall duration of radiation therapy, duration of the gap and indications of additional boost are not clear, but it is demonstrated that overall duration of treatment should be as short as possible to improve the therapeutic radio. Phase II and III studies are ongoing, to evaluate the best chemotherapy regimen between 5FU+MMC and 5FU+CDDP, the benefit of neoadjuvant or maintenance chemotherapy and the interest of increased total dose. Next future could be the utilisation of oral 5FU. This article is a review of past randomised trials, phases II and retrospective study on radiochemotherapy of anal canal carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗

New strategies in anaemia management: ACORD (Anaemia CORrection in Diabetes) trial.

Anaemia is a key component of diabetic nephropathy, but its importance has only recently been recognised. Recombinant human erythropoietin (epoetin) is an established treatment for renal anaemia, and may help to reduce complications associated with diabetic nephropathy, such as cardiovascular disease. The limited experience with the use of epoetin in this patient group prompts the urgent need for clinical data on anaemia correction in early diabetic nephropathy, particularly with regard to benefits on cardiovascular risk reduction. The Anaemia CORrection in Diabetes (ACORD) study will investigate the effects of anaemia correction on cardiac structure and function in patients with early diabetic nephropathy. This 15-month multicentre study will recruit 160 adult patients with diabetes, mild or moderate chronic kidney disease (with creatinine clearance >or=30 ml/min at screening) and moderate anaemia (haemoglobin [Hb], 10.5-13.0 g/dl). Patients will be randomised to one of two groups: the early treatment group will receive subcutaneous epoetin beta (NeoRecormon) at study entry to maintain target Hb levels of 13-15 g/dl, while the control group will reflect current practice and will not receive epoetin therapy until Hb levels decline below 10.5 g/dl. The primary efficacy variable, change in left ventricular mass index, will be evaluated at 15 months following randomisation; secondary efficacy variables will include changes in cardiac structure and function over the study period. The ACORD study should provide valuable information on the benefits of anaemia correction in patients with early diabetic nephropathy. The study will also increase awareness of the importance of treating anaemia associated with diabetes.

Anemia↗

[Calcaneal fractures--the most frequent tarsal fractures].

Operative treatment of intra-articular calcaneal fractures with anatomical reduction and early mobilisation has lead to a considerable improvement of the functional results of these severe injuries over the recent two decades. New tendencies like modified approaches tailored according to the vascular anatomy, arthroscopic control of joint reduction in conjunction with open or percutaneous procedures, early flap coverage for severe open fractures or closed fractures with full thickness skin necrosis, the use of interlocking plates that further minimises the need of bone grafting and subtalar arthrolysis at the time of hardware removal for fibrous overgrowth have the potential for further improvement of the outcome. The observation from several comparative studies that operative treatment leads to superior results in displaced intra-articular calcaneal fractures has been qualified in a recent prospective, randomised multicentre trial. This paper presents and the authors' experience with the demanding operative treatment of these fractures together with new developments aiming at improving the clinical results.

Arthroscopy↗

Evidence-based medicine: how good is the evidence?

The "evidence" in EBM must be of high quality in order to be useful, but this is not always the case. Even the "gold standard" of evidence-based medicine, the randomised clinical trial, is bedevilled by low inclusion rates and potentially important recruitment biases. "Real world" trials often do not give the same results as these highly artificial controlled clinical studies. Meta-analysis, the next most important level of evidence in EBM, may be unreliable, sometimes giving different results to subsequent large randomised trials. There is a bias in the hypotheses tested in large clinical trials, as the costs involved are usually covered by commercially interested companies. For this reason, trials of non-patentable compounds or therapies of no commercial interest may not be performed. The process of journal review and publication is capricious, slow and may have a selection bias towards positive studies, meaning that communication channels for the "evidence" are often unsatisfactory. For many rarer conditions and situations, there is simply no "high level" evidence, such as in paediatrics and subspecialty surgery.

Bias↗

[MUSTIC trial].

The atrio-bi-ventricular pacing has been used for hemodynamic improvement since 1994, and the MUSTIC trial is the first controlled study assessing this concept. It collected 67 patients with severe and stable heart failure with optimised medical therapy, with sinus rhythm and without any traditional indication for pacing. After two periods of three months with blinded randomisation and cross-over, the bi-ventricular pacing mode showed its superiority to the inactive mode concerning all study endpoints, for example with an improvement of the functional capacity of 23% assessed by the 6-minutes-walk test. Thus the MUSTIC trial opens up the way for morbidity and mortality studies.

Aged↗

Epidemiological factors in clinical trial design.

Randomised, double-blind, placebo-controlled clinical trials are human experiments in which the process of randomisation and blinded observation greatly simplify the interpretation of the results. However, epidemiological issues when properly addressed allow the optimal preparation of the study with anticipation of factors to be included in the analysis which are independent of the randomisation process but can affect the results, for example, the effect of age, dose, time since vaccination and exposure to other diseases. Alternative methods of estimating vaccine efficacy may be necessary in some settings, and such methods may have limitations which must be acknowledged in interpretation. This paper reviews some recently published studies of vaccine efficacy for the application of epidemiological principles in design and analysis.

Clinical Trials as Topic↗