Impact of clinical trials on clinical practice: example of thrombolysis for acute myocardial infarction

Current status of hyperthermic intraperitoneal chemotherapy (HIPEC) for ovarian cancer in the United States

OBJECTIVES

1.) To compare frequency of HIPEC use in ovarian cancer treatment before and after publication of the phase III study by van Driel et al. in January 2018. 2.) To compare associated rates of hospital-based outcomes, including length of stay, intensive care unit (ICU) admission, complications, and costs in ovarian cancer surgery with or without HIPEC.

METHODS

We queried Vizient's administrative claims database of 550 US hospitals for ovarian cancer surgeries from January 2016-January 2020 using ICD-10 diagnosis and procedure codes. Sodium thiosulfate administration was used to identify HIPEC cases according to the published protocol. Student t-tests and relative risk (RR) were used to compare continuous variables and contingency tables, respectively.

RESULTS

152 ovarian cancer patients had HIPEC at 39 hospitals, and 20,014 ovarian cancer patients had surgery without HIPEC at 256 hospitals. Following the trial publication, 97% of HIPEC cases occurred. During the index admission, HIPEC patients had longer median length of stay (8.4 vs. 5.7 days, p < 0.001) and higher percentage of ICU admissions (63.1% vs. 11.0%, p < 0.001) and complication rates (RR = 1.87, p = 0.002). Index admission direct costs ($21,825 vs. $12,038, p < 0.001) and direct cost index (observed/expected costs) (1.87 vs. 1.11, p < 0.001) were also greater in the HIPEC patients. No inpatient deaths or 30-day readmissions were identified after HIPEC.

CONCLUSIONS

Use of HIPEC for ovarian cancer increased in the US after publication of a phase III clinical trial in a high-impact journal, though the absolute number of cases remains modest. Incorporation of HIPEC was associated with increased cost, hospital length of stay, ICU admission, and hospital-acquired complication rates. Further studies are needed in order to evaluate long-term outcomes, including morbidity and survival.

Perioperative Beta-blockade: Guidelines and Practice in New Zealand

The aim of our study was to describe the knowledge and practice of New Zealand anaesthetists in relation to perioperative beta-adrenergic blockade, and to define barriers to implementation of perioperative beta-blockade in surgical patients at risk of myocardial ischaemia.

A survey was sent to 400 New Zealand specialist anaesthetists. Information was sought on their knowledge and current practice relating to perioperative beta-blockade, and the barriers encountered to implementing therapy.

The response rate was 59%. Perioperative beta-blockade was seen as beneficial in at risk patients by 95% of responding anaesthetists, but practice varied widely. Only 45% of anaesthetists always or usually commenced a beta blocker perioperatively, a department protocol was available to only 20%, and understanding of indications and contraindications to beta-blockade varied. There were logistical difficulties when initiating and monitoring perioperative beta-blocker regimens, and where treatment required multidisciplinary commitment. The lack of clarity of the guidelines was also a barrier to more widespread use. Difficulties were encountered relating general guidelines to individual patients, when co-morbidities, concurrent treatment and the influence of regional or general anaesthesia may influence the risk/benefit ratio.

This study has identified variations in practice and reasons why New Zealand anaesthetists use of perioperative beta-blockers is at odds with published guidelines. Deficiencies in the guidelines are part of the problem. However, even with consensus on guidelines, effective multidisciplinary strategies will be required to optimize treatment of patients at risk of perioperative cardiac events.

Continuing Education and New Zealand Anaesthetists: An Analysis of Current Practice and Future Needs

A survey of Continuing Medical Education (CME) of New Zealand anaesthetists was undertaken to identify current patterns of participation, usefulness of different activities, evidence of effectiveness, motivators and barriers to participation and to define future CME needs.

The response rate was 74% and showed high levels of participation in a range of CME activities. Ratings for usefulness differed significantly between these activities. Respondents identified specific changes they had made to their practice as a result of CME, providing strong evidence for its effectiveness.

Anaesthetists valued interactive methods of learning that were relevant to clinical practice. The most commonly reported motivators for participation were accreditation requirements and keeping up to date, while other work commitments were the commonest impediment. In this survey, interactive educational interventions were seen as useful, a finding consistent with systematic reviews of the effectiveness of CME in changing physician behaviour. Such reviews conclude that there is no evidence that conferences are effective in changing physician behaviour, yet respondents to this survey attributed many changes in practice to their attendance at a conference.

Analysis of the needs of NZ anaesthetists supports increasing the number of workshops and interactive sessions and promoting smaller meetings and practice-based activities. The survey provides a basis for designing a future program of CME for New Zealand.

Translation of Clinical Research into Practice: An Impact Assessment of the Results from the Blood and Marrow Transplant Clinical Trials Network Protocol 0201 on Unrelated Graft Source Utilization

Barriers and facilitators to adoption of results of clinical trials are substantial and poorly understood. We sought to examine whether the results of the randomized, multicenter Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0201 study comparing peripheral blood (PB) with bone marrow (BM) stem cells for unrelated donor (URD) hematopoietic cell transplantation (HCT) changed practice from PB to BM graft utilization and explored factors that impact graft selection and translation of research results into practice. The difference between use of URD BM and PB in the 2 years before and after publication of results in 2012 was examined using observational data collected by the Center for Blood and Marrow Transplant Research. A web-based survey of transplant physicians was conducted to understand the change in physician-reported personal and center preferred URD graft. No significant change in use of BM versus PB grafts occurred after 2012. Both BMT CTN participating and nonparticipating centers continued to use PB. Ninety-two percent of respondents were aware of the study results; 18% reported a change in personal and 16% reported a change in their center's practice of requesting BM instead of PB for URD HCT. Patient characteristics and the perception that engaging local champions to increase the evidence uptake were factors associated with personal or center change in practice. Despite awareness of the trial results, fewer than one-fifth of HCT physicians reported practice change in response to the BMT CTN 0201 results. Observational data confirmed no discernible change in practice.

Participation in research improves overall patient management: insights from the Global Rheumatic Heart Disease registry (REMEDY)

Background

Rheumatic heart disease (RHD) is a major public health problem in low– and middle–income countries (LMICs), with a paucity of high–quality trial data to improve patient outcomes. Investigators felt that involvement in a recent large, observational RHD study impacted positively on their practice, but this was poorly defined.

Aim

The purpose of this study was to document the experience of investigators and research team members from LMICs who participated in a prospective, multi–centre study, the global Rheumatic Heart Disease Registry (REMEDY), conducted in 25 centres in 14 countries from 2010 to 2012.

Methods

We conducted an online survey of site personnel to identify and quantify their experiences. Telephone interviews were conducted with a subset of respondents to gather additional qualitative data. We asked about their experiences, positive and negative, and about any changes in RHD management practices resulting from their participation in REMEDY as a registry site.

Results

The majority of respondents in both the survey and telephone interviews indicated that participation as a registry site improved their management of RHD patients. Administrative changes included increased attention to follow–up appointments and details in patient records. Clinical changes included increased use of penicillin prophylaxis, and more frequent INR monitoring and contraceptive counselling.

Conclusions

Our study demonstrates that participation in clinical research on RHD can have a positive impact on patient management. Furthermore, REMEDY has led to increased patient awareness and improved healthcare workers’ knowledge and efficiency in caring for RHD patients.

Effect of Randomized Clinical Trial Findings on Emergency Management

OBJECTIVES

Research findings are not consistently adopted in the clinical setting and there is a gap between best evidence and clinical practice across a range of conditions and settings. A number of factors may contribute to this discrepancy, including the direction of the research findings (i.e., whether positive or negative for an intervention). The objectives of this study were to measure the translation of results from randomized controlled trials (RCTs) into clinical care and to determine whether the direction of the trial findings influence the uptake of research reports into clinical practice.

METHODS

This was a retrospective study of clinical care provided in emergency departments (EDs) across the United States with data collected by the National Hospital Ambulatory Medical Care Survey from 1992 to 2010. RCTs published in journals with the highest impact factors and conducted in ED settings were selected and data were extracted on the interventions under study, the patient populations examined, and the trial findings. Changes in clinical practice corresponding to the RCT results were measured by comparing the rates of treatment with the intervention during the 3-year period before and after publication of the trial.

RESULTS

Twenty-one RCTs met the inclusion criteria. Ten studies reported positive interventions, of which nine (90%) were associated with an increased ED use of the intervention after trial publication. Four studies showing the lack of benefit of interventions were not used in ED practice prior to the trial and practice did not change in the postpublication period. The remaining eight trials presented negative findings or results comparing two different interventions, and of these, three (38%) were associated with small changes in the ED use of the interventions, consistent with the trial results.

CONCLUSIONS

In the ED setting, results of RCTs published in high-impact journals are more likely to be translated into clinical care when they demonstrate the benefits of an intervention. Our findings indicate that direction of research evidence is an important factor when evaluating knowledge uptake into clinical practice.

From evidence to clinical practice in blood and marrow transplantation

Clinical practice in the field of blood and marrow transplantation (BMT) has evolved over time, as a result of thousands of basic and clinical research studies. While it appears that scientific discovery and adaptive clinical research may be well integrated in case of BMT, there is lack of sufficient literature to definitively understand the process of translation of evidence to practice and if it may be selective . In this review, examples from BMT and other areas of medicine are used to highlight the state of and potential barriers to evidence uptake. Strategies to help improve knowledge transfer are discussed and the role of existing framework provided by the Center for International Blood and Marrow Transplant Registry (CIBMTR) to monitor uptake and BMT Clinical Trials Network (BMT CTN) to enhance translation of evidence into practice is highlighted.

Surveillance epidemiology and end results analysis demonstrates improvement in overall survival for cervical cancer patients treated in the era of concurrent chemoradiotherapy

Background

In February 1999, the National Cancer Institute (NCI) issued a clinical alert based on five randomized trials that reported better overall survival (OS) with concurrent chemoradiotherapy (CCRT) than with surgery or radiation alone for locoregional cervical cancer. This study analyzes data from the surveillance epidemiology and end results (SEER) program to evaluate the improvement in survival in the era of CCRT.

Methods

The SEER database was queried for FIGO stages IB2–IVA cervical cancer patients treated with radiotherapy between 1995 and 2002. Patients diagnosed between 1999 and 2002 (CCRT era) were assumed to have received CCRT more frequently than patients diagnosed between 1995 and 1998 (RT era). Cases were stratified by period of diagnosis, age, and SEER region. OS and cause specific survival (CSS) were compared between the two time periods with chi-square log-rank tests. Multivariable Cox models were also used to compare OS and CSS between the two time periods, with adjustment for stratification variables and other covariates.

Results

The study included 3517 patients. Unadjusted OS and CSS were significantly improved in 1999–2002 compared with 1995–1998 (OS: p < 0.001, hazard ratio (HR): 0.81; CSS: p < 0.001, HR: 0.79). Significant improvements in OS and CSS were retained after adjustment for multiple variables (multivariable OS HR 0.78; CSS HR 0.76).

Conclusion

Cervical cancer patients treated with radiotherapy after 1999 had improved OS and CSS compared with patients treated before 1999, likely reflecting increased usage of CCRT. This study adds to the population-level evidence supporting the adoption of CCRT as the standard of care for locoregional cervical cancer.

Declining Long-term Risk of Adverse Events after First-time Community-presenting Venous Thromboembolism: The Population-based Worcester VTE Study (1999 to 2009)

INTRODUCTION

Contemporary trends in health-care delivery are shifting the management of venous thromboembolism (VTE) events (deep vein thrombosis [DVT] and/or pulmonary embolism [PE]) from the hospital to the community, which may have implications for its prevention, treatment, and outcomes.

MATERIALS AND METHODS

Population-based surveillance study monitoring trends in clinical epidemiology among residents of the Worcester, Massachusetts, metropolitan statistical area (WMSA) diagnosed with an acute VTE in all 12 WMSA hospitals. Patients were followed for up to 3 years after their index event. Total of 2334 WMSA residents diagnosed with first-time community-presenting VTE (occurring in an ambulatory setting or diagnosed within 24 hours of hospitalization) from 1999 through 2009.

RESULTS

While PE patients were consistently admitted to the hospital for treatment over time, the proportion diagnosed with DVT-alone admitted to the hospital decreased from 67% in 1999 to 37% in 2009 (p value for trend <0.001). Among hospitalized patients, the mean length of stay decreased from 5.6 to 4.8 days (p value for trend <0.001). Between 1999 and 2009, treatment of VTE shifted from warfarin and unfractionated heparin towards use of low-molecular-weight heparins and newer anticoagulants; also, 3-year cumulative event rates decreased for all-cause mortality (41-26%), major bleeding (12-6%), and recurrent VTE (17-9%).

CONCLUSIONS

A decade of change in VTE management was accompanied by improved long-term outcomes. However, rates of adverse events remained fairly high in our population-based surveillance study, implying that new risk-assessment tools to identify individuals at increased risk for developing major adverse outcomes over the long term are needed.

HALT-IT--tranexamic acid for the treatment of gastrointestinal bleeding: study protocol for a randomised controlled trial

Background

Gastrointestinal bleeding is a common emergency that causes substantial mortality worldwide. Acute upper and lower gastrointestinal bleeding accounts for about 75,000 hospital admissions each year in the UK and causes the death of about 10% of these patients.

Tranexamic acid has been shown to reduce the need for blood transfusion in surgical patients and to reduce mortality in bleeding trauma patients, with no apparent increase in thromboembolic events.

A systematic review of clinical trials of upper gastrointestinal bleeding shows a reduction in the risk of death with tranexamic acid but the quality of the trials was poor and the estimates are imprecise. The trials were also too small to assess the effect of tranexamic acid on thromboembolic events.

Methods

HALT-IT is a pragmatic, randomised, double-blind, placebo-controlled trial which will determine the effect of tranexamic acid on mortality, morbidity (re-bleeding, non-fatal vascular events), blood transfusion, surgical intervention, and health status in patients with acute gastrointestinal bleeding. Eight thousand adult patients who fulfil the eligibility criteria will be randomised to receive tranexamic acid or placebo.

Adults with significant acute upper or lower gastrointestinal bleeding can be included if the responsible doctor is substantially uncertain as to whether or not to use tranexamic acid in that particular patient.

Trial treatment consists of a loading dose of tranexamic acid (1 g by intravenous injection) or placebo (sodium chloride 0.9%) given as soon as possible after randomisation, followed by an intravenous infusion of 3 g tranexamic acid or placebo (sodium chloride 0.9%) over 24 hours.

The main analyses will compare those allocated tranexamic acid with those allocated placebo, on an intention-to-treat basis. Results will be presented as effect estimates with a measure of precision (95% confidence intervals). Subgroup analyses for the primary outcome will be based on time to treatment, source of bleeding (upper versus lower), suspected variceal bleeding and severity of bleeding. A study with 8,000 patients will have over 90% power to detect a 25% reduction in mortality from 10% to 7.5%.

Trial registration

Current Controlled Trials ISRCTN11225767 (registration date: 3 July 2012); Clinicaltrials.gov NCT01658124 (registration date: 26 July 2012).

Electronic supplementary material

The online version of this article (doi:10.1186/1745-6215-15-450) contains supplementary material, which is available to authorized users.

Does recruitment for multicenter clinical trials improve dissemination and timely implementation of their results? A survey study from the Netherlands

Background

Results from clinical trials are often slowly implemented. We studied whether participation in multicenter clinical trials improves reported dissemination, convincement, and subsequent implementation of its results.

Methods

We sent a web-based questionnaire to gynecologists, residents, nurses, and midwives in all obstetrics and gynecology departments in the Netherlands. For nine trials in perinatology, reproductive medicine, and gynecologic oncology, we asked the respondents whether they had knowledge of the results, were convinced by the results, and what percentage of their patients were treated according to the results of these trials. We compared the level of knowledge, convincement, and reported implementation of results in practice for the nine trials for respondents who worked in hospitals that had recruited for a trial with respondents who worked in a hospital that had not recruited for that trial. The reported implementation was restricted to six trials that showed decisive results.

Results

We analyzed 202 questionnaires from 83 departments in obstetrics and gynecology in the Netherlands (93% of all departments). The percentage of respondents who had worked in a hospital that recruited for a specific study varied between 8% and 71% per study and was 28% on average. The relative risk (RR) for knowledge of the study result for respondents who had worked in a recruiting hospital was for all studies positive and varied between 1.1 and 3.3 (pooled RR: 1.8, 95% confidence interval (CI): 1.7–1.9). In general, health-care workers were convinced of trial results, independent of whether they had worked in a hospital that recruited for a trial or not (pooled RR: 1.02, 95% CI: 0.99–1.05). Reported implementation of trial’s results, that is, less than 20% were treated with unfavorable treatment according to study results, was better in hospitals that had recruited for those trials (pooled RR: 1.1, 95% CI: 1.02–1.19).

Conclusion

Participation in these multicenter clinical trials was associated with better knowledge about the trial’s results, with a minor improvement of the reported implementation of the study results.

Stroke Rehabilitation

The need for stroke rehabilitation will lessen if stroke incidence declines and acute stroke medical and surgical treatment improves. The burden of stroke will also lessen as effective rehabilitation services (stroke rehabilitation units) and interventions are widely implemented. Despite the considerable amount of evidence available, implementation has been slow. Improvement in stroke rehabilitation will require continued professional advocacy, supported by local and national audit and future focused research.

Impact of practice recommendations on patient follow-up and cystic fibrosis centres' activity in France

INTRODUCTION

The French cystic fibrosis (CF) practice recommendations were published at the end of 2002. They advise each patient to be checked up at least once every 3 months in a reference centre for cystic fibrosis.

OBJECTIVE

To describe the activity of the four reference centres in the Rhône-Alpes area and the patients' follow-up.

METHODS

All patients with cystic fibrosis consulting one of the four CF centres between 1996 and 2005 were retrospectively included. All outpatient visits were recorded and classified according to (i) patient and year; and (ii) month and year. The two series were assessed graphically to determine a transition threshold, that is, the 2 consecutive years between which practices differed the most.

RESULTS

A total of 616 patients were included, representing 17 594 outpatient visits. The average number of visits per patient increased from 3.7 in 1996 to 5.0 in 2005, the graphical representation showed a sharp change between 2000 and 2001. Among patients with less than 4 visits in 2000, 88 of them visited a centre 4 times or more in 2001 (44%). The annual number of outpatient visits went from 1035 to 2420. The monthly average number of outpatient visits was 86 in 1996 and 202 in 2005. The graphical representation of activity also showed a sharp change from 2001.

CONCLUSION

We showed that the implementation of guidelines occurred the year before its official publication. We also showed that the growth of this implementation was sharp rather than gradual.

The WOMAN Trial (World Maternal Antifibrinolytic Trial): tranexamic acid for the treatment of postpartum haemorrhage: an international randomised, double blind placebo controlled trial

BACKGROUND

Each year, worldwide about 530,000 women die from causes related to pregnancy and childbirth. Of the deaths 99% are in low and middle income countries. Obstetric haemorrhage is the leading cause of maternal mortality, most occurring in the postpartum period. Systemic antifibrinolytic agents are widely used in surgery to prevent clot breakdown (fibrinolysis) in order to reduce surgical blood loss. At present there is little reliable evidence from randomised trials on the effectiveness of tranexamic acid in the treatment of postpartum haemorrhage.

METHODS

The Trial aims to determine the effect of early administration of tranexamic acid on mortality, hysterectomy and other morbidities (surgical interventions, blood transfusion, risk of non-fatal vascular events) in women with clinically diagnosed postpartum haemorrhage. The use of health services and safety, especially thromboembolic effect, on breastfed babies will also be assessed. The trial will be a large, pragmatic, randomised, double blind, placebo controlled trial among 15,000 women with a clinical diagnosis of postpartum haemorrhage. All legally adult women with clinically diagnosed postpartum haemorrhage following vaginal delivery of a baby or caesarean section will potentially be eligible. The fundamental eligibility criterion is the responsible clinician's 'uncertainty' as to whether or not to use an antifibrinolytic agent in a particular woman with postpartum haemorrhage. Treatment will entail a dose of tranexamic acid (1 gram by intravenous injection) or placebo (sodium chloride 0.9%) will be given as soon as possible after randomisation. A second dose may be given if after 30 minutes bleeding continues, or if it stops and restarts within 24 hours after the first dose. The main analyses will be on an 'intention to treat' basis, irrespective of whether the allocated treatment was received or not. Subgroup analyses for the primary outcome will be based on type of delivery; administration or not of prophylactic uterotonics; and on whether the clinical decision to consider trial entry was based primarily on estimated blood loss alone or on haemodynamic instability. A study with 15,000 women will have over 90% power to detect a 25% reduction from 4% to 3% in the primary endpoint of mortality or hysterectomy.

Influence of clinical trial participation on subsequent antithrombin use

BACKGROUND

Results from the Superior Yield of the New Strategy of Enoxaparin, Revascularization, and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) trial showed that the low-molecular-weight heparin (LMWH) enoxaparin was non-inferior compared with unfractionated heparin (UFH) in patients with non-ST-elevation acute coronary syndromes (NSTE-ACS) managed invasively.

HYPOTHESIS

We explored the influence of SYNERGY trial site participation on subsequent patterns of heparin use for NSTE-ACS patients treated in routine practice.

METHODS

We examined temporal patterns of LMWH use compared with UFH use among 122 764 patients with NSTE-ACS enrolled in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC/AHA Guidelines (CRUSADE) quality improvement initiative between January 1, 2002 and June 30, 2006, to determine whether site participation in SYNERGY influenced the type of heparin used before and after publication of the SYNERGY results in July 2004.

RESULTS

A total of 118 out of 388 (30%) U.S. hospitals participating in CRUSADE simultaneously participated in SYNERGY. SYNERGY sites in the CRUSADE registry were more likely to have a teaching affiliation and have more hospital beds than non-SYNERGY centers in the registry. There was no difference in the proportion of patients treated with LMWH at SYNERGY and non-SYNERGY sites prior to July 2004 compared with after July 2004. However, at SYNERGY sites, there was a slight decrease in the proportion of patients treated with both UFH and LMWH within 24 hours of presentation.

CONCLUSIONS

The results of the SYNERGY trial did not appear to influence temporal patterns of LMWH use at sites in the CRUSADE registry. Furthermore, site participation in the SYNERGY trial did not alter patterns of LMWH use for NSTE-ACS after publication of the trial results in July 2004.

The molecular basis of thrombolysis and its clinical application in stroke

The rationale for thrombolysis, the most promising pharmacological approach in acute ischaemic stroke, is centred on the principal cause of most ischaemic strokes: the thrombus that occludes the cerebral artery, and renders part of the brain ischaemic. The occluding thrombus is bound together within fibrin. Fibrinolysis acts by activation of plasminogen to plasmin; plasmin splits fibrinogen and fibrin and lyses the clot, which then allows reperfusion of the ischaemic brain. Thrombolytic agents include streptokinase (SK) and recombinant tissue-type plasminogen activator (rt-PA) amongst others under test or development. SK is nonfibrin-specific, has a longer half-life than tissue-type plasminogen activator (t-PA), prevents re-occlusion and is degraded enzymatically in the circulation. rt-PA is more fibrin-specific and clot-dissolving, and is metabolized during the first passage in the liver. In animal models of ischaemic stroke, the effects of rt-PA are remarkably consistent with the effects seen in human clinical trials. For clinical application, some outcome data from the Cochrane Database of Systematic Reviews which includes all randomized evidence available on thrombolysis in man were used. Trials included tested urokinase, SK, rt-PA, pro-urokinase, or desmoteplase. The chief immediate hazard of thrombolytic therapy is fatal intracranial bleeding. However, despite the risk, the human trial data suggest the immediate hazards and the apparent substantial scope for net benefit of thrombolytic therapy given up to 6 h of acute ischaemic stroke. So far the fibrin-specific rt-PA is the only agent to be approved for use in stroke. This may be due to its short half-life and its absence of any specific amount of circulating fibrinogen degradation products, thereby leaving platelet function intact. The short half-life does not leave rt-PA without danger for haemorrhage after the infusion. Due to its fibrin-specificity, it can persist within a fibrin-rich clot for one or more days. The molecular mechanisms with regards to fibrin-specificity in thrombolytic agents should, if further studied, be addressed in within-trial comparisons. rt-PA has antigenic properties and although their long-term clinical relevance is unclear there should be surveillance for allergic reactions in relation to treatment. Although rt-PA is approved for use in selected patients, there is scope for benefit in a much wider variety of patients. A number of trials are underway to assess which additional patients - beyond the age and time limits of the current approval - might benefit, and how best to identify them.

Facilitating knowledge transfer with single-center trials

OBJECTIVE

To provide perspective for clinicians as they evaluate incorporating single-center trials and small randomized, controlled trials for use in daily practice by reviewing examples from the literature.

METHODS

Selected examples from the literature, such as check lists, daily screens for weaning readiness, daily spontaneous breathing trials, early resuscitation in sepsis, and daily interruption of sedation are reviewed and the effect of these studies is discussed.

RESULTS

Some single-center trials are adopted rapidly without confirmatory trials. These have then been incorporated into further protocols that have also demonstrated positive results, which illustrate the value of implementing some single-center trials into routine clinical practice. Even with robust published data, knowledge transfer of research results is traditionally slow. Given the negative results of some confirmatory trials, clinicians should carefully appraise published studies and decide whether the results are appropriate for a given patient population.

CONCLUSIONS

The results from single-center trials may have an important impact on patient care. Current data do not support the assumption that all single-center trials must be confirmed before adopting the results into clinical practice. Clinicians must carefully evaluate the results of single-center trials within the context of their clinical experience and the preferences of their patients to determine how best to translate research to the bedside.

Thrombolysis for acute ischaemic stroke

BACKGROUND

The majority of strokes are due to blockage of an artery in the brain by a blood clot. Prompt treatment with thrombolytic drugs can restore blood flow before major brain damage has occurred and could improve recovery after stroke. Thrombolytic drugs, however, can also cause serious bleeding in the brain, which can be fatal. One drug, recombinant tissue plasminogen activator (rt-PA), is licensed for use in highly selected patients within three hours of stroke.

OBJECTIVES

To assess the safety and efficacy of thrombolytic agents in patients with acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched October 2008), MEDLINE (1966 to October 2008) and EMBASE (1980 to October 2008). We contacted researchers and pharmaceutical companies, attended relevant conferences and handsearched pertinent journals.

SELECTION CRITERIA

Randomised trials of any thrombolytic agent compared with control in patients with definite ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors applied the inclusion criteria and extracted data. We assessed trial quality. We verified the extracted data with the principal investigators of all major trials. We obtained both published and unpublished data if available.

MAIN RESULTS

We included 26 trials involving 7152 patients. Not all trials contributed data to each outcome. The trials tested urokinase, streptokinase, recombinant tissue plasminogen activator, recombinant pro-urokinase or desmoteplase. Four trials used intra-arterial administration, the rest used the intravenous route. Most data come from trials that started treatment up to six hours after stroke; three trials started treatment up to nine hours and one small trial up to 24 hours after stroke. About 55% of the data (patients and trials) come from trials testing intravenous tissue plasminogen activator. Very few of the patients (0.5%) were aged over 80 years. Many trials had some imbalances in key prognostic variables. Several trials did not have complete blinding of outcome assessment. Thrombolytic therapy, mostly administered up to six hours after ischaemic stroke, significantly reduced the proportion of patients who were dead or dependent (modified Rankin 3 to 6) at three to six months after stroke (odds ratio (OR) 0.81, 95% confidence interval (CI) 0.73 to 0.90). Thrombolytic therapy increased the risk of symptomatic intracranial haemorrhage (OR 3.49, 95% CI 2.81 to 4.33) and death by three to six months after stroke (OR 1.31, 95% CI 1.14 to 1.50). Treatment within three hours of stroke appeared more effective in reducing death or dependency (OR 0.71, 95% CI 0.52 to 0.96) with no statistically significant adverse effect on death (OR 1.13, 95% CI 0.86 to 1.48). There was heterogeneity between the trials in part attributable to concomitant antithrombotic drug use (P = 0.02), stroke severity and time to treatment. Antithrombotic drugs given soon after thrombolysis may increase the risk of death.

AUTHORS' CONCLUSIONS

Overall, thrombolytic therapy appears to result in a significant net reduction in the proportion of patients dead or dependent in activities of daily living. This overall benefit was apparent despite an increase both in deaths (evident at seven to 10 days and at final follow up) and in symptomatic intracranial haemorrhages. Further trials are needed to identify which patients are most likely to benefit from treatment and the environment in which thrombolysis may best be given in routine practice.

In-hospital mortality of elderly patients with acute myocardial infarction: data from the MITRA (Maximal Individual Therapy in Acute Myocardial Infarction) registry

BACKGROUND

Advanced age remains one of the principal determinants of mortality in patients with acute myocardial infarction (AMI).

HYPOTHESIS

The aim of this study was to determine the in-hospital outcome of elderly (> 75 years) patients with AMI who were admitted to hospitals participating in the national MITRA (Maximal Individual Therapy in Acute Myocardial Infarction) registry.

METHODS

MITRA is a prospective, observational German multicenter registry investigating current treatment modalities for patients presenting with AMI. All patients with AMI admitted within 96 h of onset of symptoms were included in the MITRA registry. MITRA was started in June 1994 and ended in January 1997. This registry comprises 6,067 consecutive patients with a mean age of 65 +/- 12 years, of whom 1,430 (17%) were aged > 75 years. Patients were compared with respect to patient characteristics, prehospital delays, early treatment strategies, and clinical outcome.

RESULTS

In the elderly patient population, the prehospital delay was 210 min, which was significantly longer than that for younger patients (155 min, p = 0.001). Although the incidence of potential contraindications for the initiation of thrombolysis was almost equally distributed between the two age groups (8.7 vs. 8.2%, p = NS), elderly patients (> 75 years) received reperfusion therapy less frequently (35.9 vs. 64.6%) than younger patients. Mortality increased with advanced age and was 26.4% for all patients aged > 75 years. If reperfusion therapy was initiated, in-hospital mortality was 21.8 versus 28.9% in patients aged > 75 years (p = 0.001) and 29.4 versus 38.5% in patients aged > 85 years (p = 0.001).

CONCLUSION

In this registry, elderly patients with AMI had a much higher in-hospital mortality than that expected from randomized trials. In MITRA, the mortality reduction with reperfusion therapy was found to be highest in the very elderly patient population.

Practice and perception--a nationwide survey of therapy habits in sepsis

OBJECTIVE

To simultaneously determine perceived vs. practiced adherence to recommended interventions for the treatment of severe sepsis or septic shock.

DESIGN

One-day cross-sectional survey.

SETTING

Representative sample of German intensive care units stratified by hospital size.

PATIENTS

Adult patients with severe sepsis or septic shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Practice recommendations were selected by German Sepsis Competence Network (SepNet) investigators. External intensivists visited intensive care units randomly chosen and asked the responsible intensive care unit director how often these recommendations were used. Responses "always" and "frequently" were combined to depict perceived adherence. Thereafter patient files were audited. Three hundred sixty-six patients on 214 intensive care units fulfilled the criteria and received full support. One hundred fifty-two patients had acute lung injury or acute respiratory distress syndrome. Low-tidal volume ventilation < or = 6 mL/kg/predicted body weight was documented in 2.6% of these patients. A total of 17.1% patients had tidal volume between 6 and 8 mL/kg predicted body weight and 80.3% > 8 mL/kg predicted body weight. Mean tidal volume was 10.0 +/- 2.4 mL/kg predicted body weight. Perceived adherence to low-tidal volume ventilation was 79.9%. Euglycemia (4.4-6.1 mmol/L) was documented in 6.2% of 355 patients. A total of 33.8% of patients had blood glucose levels < or = 8.3 mmol/L and 66.2% were hyperglycemic (blood glucose > 8.3 mmol/L). Among 207 patients receiving insulin therapy, 1.9% were euglycemic, 20.8% had blood glucose levels < or = 8.3 mmol/L, and 1.0% were hypoglycemic. Overall, mean maximal glucose level was 10.0 +/- 3.6 mmol/L. Perceived adherence to strict glycemic control was 65.9%. Although perceived adherence to recommendations was higher in academic and larger hospitals, actual practice was not significantly influenced by hospital size or university affiliation.

CONCLUSIONS

This representative survey shows that current therapy of severe sepsis in German intensive care units complies poorly with practice recommendations. Intensive care unit directors perceive adherence to be higher than it actually is. Implementation strategies involving all intensive care unit staff are needed to overcome this gap between current evidence-based knowledge, practice, and perception.

Participation in clinical trials may improve care of acute schizophrenia inpatients in a general hospital

INTRODUCTION

This report demonstrates parameters of quality of care and treatment outcome of acute schizophrenia patients who were involved as subjects in a clinical trial of two marketed widely used antipsychotics compared with their fellow patients who received routine clinical hospital care.

METHODS

Patients were newly admitted severely agitated schizophrenia patients who agreed to participate in a double-blind randomized trial of short-term (5 days) rate of improvement in response to two second-generation oral antipsychotics. Treatment outcomes as measured by the Clinical Global Impression and parameters of quality of care were compared with the general population of inpatients in the same county hospital.

RESULTS

Of 145 patients screened, 109 patients did not meet study inclusion and exclusion criteria. It is of note that systematic diagnostic interview did not confirm the clinical diagnosis of schizophrenia in 17 patients (11.7%). Study patients had shorter length of stay (6.75 days vs 15.3 days of total psychiatric patients at the hospital during the study period), no physical restraints (vs 21.9%), no use of antipsychotics as chemical restraints (vs 19.8%), and less recidivism following the trial (28.1%) compared with prior to the trial (64.3%).

CONCLUSION

Patients who participate in structured clinical research with well-delineated procedures, clinical outcome measures, and clear expectations, fared better than their fellow patients in the same non-research hospital wards. Application of some characteristics of clinical research to the diagnosis and treatment of clinical non-research patients may be considered.

Printed educational materials: effects on professional practice and health care outcomes

BACKGROUND

Printed educational materials (PEMs) are widely used passive dissemination strategies to improve knowledge, awareness, attitudes, skills, professional practice and patient outcomes. Traditionally they are presented in paper formats such as monographs, publication in peer-reviewed journals and clinical guidelines and appear to be the most frequently adopted method for disseminating information.

OBJECTIVES

To determine the effectiveness of PEMs in improving process outcomes (including the behaviour of healthcare professionals) and patient outcomes. To explore whether the effect of characteristics of PEMs (e.g., source, content, format, mode of delivery, timing/frequency, complexity of targeted behaviour change) can influence process outcomes (including the behaviour of healthcare professionals and patient outcomes).

SEARCH STRATEGY

The following electronic databases were searched up to July 2006: (a) The EPOC Group Specialised Register (including the database of studies awaiting assessment (see 'Specialised Register'under 'Group Details'); (b) The Cochrane Central Register of Controlled Trials (CENTRAL) and the Database of Abstracts of Reviews of Effectiveness; (c) MEDLINE, EMBASE, CINAHL and CAB Health. An updated search of MEDLINE was done in March 2007.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) , controlled clinical trials (CCT), controlled before and after studies (CBAs) and interrupted time series analyses (ITS) that evaluated the impact of printed educational materials on healthcare professionals' practice and/or patient outcomes. There was no language restriction. Any objective measure of professional performance (sch as number of tests ordered, prescriptions for a particular drug), or patient health outcomes (e.g., blood pressure, number of caesarean sections) were included.

DATA COLLECTION AND ANALYSIS

Four reviewers undertook data abstraction independently using a modified version of the EPOC data collection checklist. Any disagreement was resolved by discussion among the reviewers and arbitrators. Statistical analysis was based upon consideration of dichotomous process outcomes, continuous process outcomes, patient outcome dichotomous measures and patient outcome continuous measures. We presented the results for all comparisons using a standard method of presentation where possible. We reported separately for each study the median effect size for each type of outcome, and the median of these effect sizes across studies.

MAIN RESULTS

Twenty-three studies were included for this review. Evidence from this review showed that PEMs appear to have small beneficial effects on professional practice. RCTs comparing PEMs to no intervention observed an absolute risk difference median: +4.3% on categorical process outcomes (e.g., x-ray requests, prescribing and smoking cessation activities) (range -8.0% to +9.6%, 6 studies), and a relative risk difference +13.6% on continuous process outcomes (e.g., medication change, x-rays requests per practice) (range -5.0% to +26.6%, 4 studies). These findings are similar to those reported for the ITS studies, although significantly larger effect sizes were observed (relative risk difference range from 0.07% to 31%). In contrast, the median effect size was -4.3% for patient outcome categorical measures (e.g., screening, return to work, quit smoking) (range -0.4% to -4.6%, 3 studies)). Two studies reported deteriorations in continuous patient outcome data (e.g., depression score, smoking cessation attempts) of -10.0% and -20.5%. One study comparing PEMs with educational workshops observed minimal differences. Two studies comparing PEMs and education outreach did not have statistically significant differences between the groups. It was not possible to explore potential effect modifiers across studies.

AUTHORS' CONCLUSIONS

The results of this review suggest that when compared to no intervention, PEMs when used alone may have a beneficial effect on process outcomes but not on patient outcomes. Despite this wide of range of effects reported for PEMs, clinical significance of the observed effect sizes is not known. There is insufficient information about how to optimise educational materials. The effectiveness of educational materials compared to other interventions is uncertain.

Developing the content of two behavioural interventions: using theory-based interventions to promote GP management of upper respiratory tract infection without prescribing antibiotics #1

Evidence shows that antibiotics have limited effectiveness in the management of upper respiratory tract infection (URTI) yet GPs continue to prescribe antibiotics. Implementation research does not currently provide a strong evidence base to guide the choice of interventions to promote the uptake of such evidence-based practice by health professionals. While systematic reviews demonstrate that interventions to change clinical practice can be effective, heterogeneity between studies hinders generalisation to routine practice. Psychological models of behaviour change that have been used successfully to predict variation in behaviour in the general population can also predict the clinical behaviour of healthcare professionals. The purpose of this study was to design two theoretically-based interventions to promote the management of upper respiratory tract infection (URTI) without prescribing antibiotics.

METHOD

Interventions were developed using a systematic, empirically informed approach in which we: selected theoretical frameworks; identified modifiable behavioural antecedents that predicted GPs intended and actual management of URTI; mapped these target antecedents on to evidence-based behaviour change techniques; and operationalised intervention components in a format suitable for delivery by postal questionnaire.

RESULTS

We identified two psychological constructs that predicted GP management of URTI: "Self-efficacy," representing belief in one's capabilities, and "Anticipated consequences," representing beliefs about the consequences of one's actions. Behavioural techniques known to be effective in changing these beliefs were used in the design of two paper-based, interactive interventions. Intervention 1 targeted self-efficacy and required GPs to consider progressively more difficult situations in a "graded task" and to develop an "action plan" of what to do when next presented with one of these situations. Intervention 2 targeted anticipated consequences and required GPs to respond to a "persuasive communication" containing a series of pictures representing the consequences of managing URTI with and without antibiotics.

CONCLUSION

It is feasible to systematically develop theoretically-based interventions to change professional practice. Two interventions were designed that differentially target generalisable constructs predictive of GP management of URTI. Our detailed and scientific rationale for the choice and design of our interventions will provide a basis for understanding any effects identified in their evaluation.

TRIAL REGISTRATION

Clinicaltrials.gov NCT00376142.

Evolution of mechanical ventilation in response to clinical research

RATIONALE

Recent literature in mechanical ventilation includes strong evidence from randomized trials. Little information is available regarding the influence of these trials on usual clinical practice.

OBJECTIVES

To describe current mechanical ventilation practices and to assess the influence of interval randomized trials when compared with findings from a 1998 cohort.

METHODS

A prospective international observational cohort study, with a nested comparative study performed in 349 intensive care units in 23 countries. We enrolled 4,968 consecutive patients receiving mechanical ventilation over a 1-month period. We recorded demographics and daily data related to mechanical ventilation for the duration of ventilation. We systematically reviewed the literature and developed 11 practice-change hypotheses for the comparative cohort study before seeing these results. In assessing practice changes, we only compared data from the 107 intensive care units (1,675 patients) that also participated in the 1998 cohort (1,383 patients).

MEASUREMENTS AND MAIN RESULTS

In 2004 compared with 1998, the use of noninvasive ventilation increased (11.1 vs. 4.4%, P < 0.001). Among patients with acute respiratory distress syndrome, tidal volumes decreased (7.4 vs. 9.1 ml/kg, P < 0.001) and positive end-expiratory pressure levels increased slightly (8.7 vs. 7.7 cm H(2)O, P = 0.02). More patients were successfully extubated after their first attempt of spontaneous breathing (77 vs. 62%, P < 0.001). Use of synchronized intermittent mandatory ventilation fell dramatically (1.6 vs. 11%, P < 0.001). Observations confirmed 10 of our 11 practice-change hypotheses.

CONCLUSIONS

The strong concordance of predicted and observed practice changes suggests that randomized trial results have advanced mechanical ventilation practices internationally.

Translating clinicians' beliefs into implementation interventions (TRACII): a protocol for an intervention modeling experiment to change clinicians' intentions to implement evidence-based practice

BACKGROUND

Biomedical research constantly produces new findings, but these are not routinely incorporated into health care practice. Currently, a range of interventions to promote the uptake of emerging evidence are available. While their effectiveness has been tested in pragmatic trials, these do not form a basis from which to generalise to routine care settings. Implementation research is the scientific study of methods to promote the uptake of research findings, and hence to reduce inappropriate care. As clinical practice is a form of human behaviour, theories of human behaviour that have proved to be useful in other settings offer a basis for developing a scientific rationale for the choice of interventions.

AIMS

The aims of this protocol are 1) to develop interventions to change beliefs that have already been identified as antecedents to antibiotic prescribing for sore throats, and 2) to experimentally evaluate these interventions to identify those that have the largest impact on behavioural intention and behavioural simulation.

DESIGN

The clinical focus for this work will be the management of uncomplicated sore throat in general practice. Symptoms of upper respiratory tract infections are common presenting features in primary care. They are frequently treated with antibiotics, and research evidence is clear that antibiotic treatment offers little or no benefit to otherwise healthy adult patients. Reducing antibiotic prescribing in the community by the "prudent" use of antibiotics is seen as one way to slow the rise in antibiotic resistance, and appears safe, at least in children. However, our understanding of how to do this is limited. Participants will be general medical practitioners. Two theory-based interventions will be designed to address the discriminant beliefs in the prescribing of antibiotics for sore throat, using empirically derived resources. The interventions will be evaluated in a 2 x 2 factorial randomised controlled trial delivered in a postal questionnaire survey. Two outcome measures will be assessed: behavioural intention and behavioural simulation.

New tools to measure discrepancy between prescribing practices and guideline recommendations

OBJECTIVE

To study the performance of a new method designed to measure discrepancy between real prescriptions and evidence-based reference treatments.

METHODS

Two different indices (additive and multiplicative) are proposed to summarize deviation between prescription and reference. Deviations thought to be observed in a population of prescribers are simulated in diverse hypothetical situations in the presence or absence of evidence-based references. The performances of both indices are compared and their sensitivities to change are explored.

RESULTS

Both indices are sensitive to variation in prescriber behaviour. The additive index allows a more accurate analysis of deviation while the multiplicative index is simpler to implement and interpret but more sensitive to change.

CONCLUSION

The two deviation indices may be used as new tools in surveys or trials dealing with prescribing practices.

How to measure non-consistency of medical practices with available evidence in therapeutics: a methodological framework

Since the early 1980s many studies showed a gap between available evidence and medical practice. They were designed to assess the real impact of randomized clinical trials on the practice of medicine. Their results substantiated a knowledge translation problem. However, they were qualitative findings, i.e. a gap exists or not, although the problem is quantitative (how large is the gap?) and has several components that should be documented according to the objective of the study. In this article, we explored the components and the various contexts in which the measure of the distance between practice and knowledge is considered. All these features should be taken into account for a more accurate and relevant assessment of the distance.

Gynecologists’ attitudes towards hormone therapy in the post “Women's Health Initiative” study era

OBJECTIVE

To assess the impact of the Women's Health Initiative (WHI) study on gynecologists' attitudes regarding hormone therapy (HT).

METHODS

Questionnaires were mailed to a random sample of Lebanese gynecologists (n=178). The questionnaires solicited practice patterns of HT for postmenopausal women and information provided while counseling before and after the WHI study. Descriptive statistical methods were used to evaluate the responses.

RESULTS

Questionnaires were returned by 140 physicians (78.7%), 93.6% of whom were aware of the WHI study. More than 90% of respondents routinely offered HT prior to the study. Of the 85.6% who used a combination of oral estrogen and progesterone (E/P), 40.0% used conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA). Around 67% of gynecologists reported a change in their therapeutic approach after the study. The main changes were: not offering CEE+MPA (27.3%), prescribing CEE+MPA to a select group of patients (37.5%), using other forms of HT (56.8%), or abandoning any form of HT (6.8%). Other practice modifications included a shift to the use of tibolone (18.2%) or alternative therapies (29.5%). Whereas 76.2% of physicians counseled their patients about a decreased risk of cardiovascular events with HT prior to WHI study, only 34.1% continued to do so after the study (p<0.001). The percentage of gynecologists that inform their patients of an increased risk of breast cancer on HT rose from 45.2 to 73.2% (p=0.018). Almost 51% of gynecologists allow their patients to participate in decision making regarding the type of HT, 42.4% would choose for their patients after counseling, while 6.8% of physicians do not counsel their patients in order not to confuse them.

CONCLUSION

In a representative sample of Lebanese gynecologists, there was a significant change in physicians' attitudes towards HT following the publication of the WHI study.

Tracking publication outcomes of National Institutes of Health grants

PURPOSE

The peer-review literature is the primary medium through which the findings of funded research are evaluated by and disseminated to the broader scientific community. This study examines when and how grants funded by the National Institutes of Health (NIH) lead to publications.

METHODS

Data on all investigator-initiated R01 grants funded during 1996 (n = 18211) were extracted from the NIH's Computer Retrieval of Information on Scientific Projects Web site. These data were linked with all MEDLINE articles published during and up through 4 years after completion of each grant using NIH grant numbers reported in the manuscript. Analyses examined the number, timing, and correlates of all linked publications and publications in core journals (179 journals, comprising the top 100 Institute for Scientific Information or 120 Abridged Index Medicus journals).

RESULTS

On average, each grant produced 7.6 MEDLINE manuscripts (95% confidence interval [CI]: 7.47 to 7.69) and 1.61 publications in a core journal (95% CI: 1.56 to 1.65). In multivariable analyses among universities, more manuscripts and publications in core journals were seen for competing renewals versus new grants, for projects reviewed by basic science study sections, for full professors, and for universities with graduate programs ranked in the top 10 by US News and World Report. However, all grant, investigator, and institutional strata produced substantial numbers of publications per grant.

CONCLUSIONS

The findings support the feasibility and potential utility of efforts to study the link between grant funding and research findings, an early step in the process by which funded science leads to improved clinical and public health.

Influence of the randomized trials, AFFIRM and RACE, on the management of atrial fibrillation in two University Medical Centers

The results of the Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) and the Rate Control Versus Electrical Cardioversion for Persistent Atrial Fibrillation (RACE) study were presented in March 2002. These large studies showed no benefit of a rhythm-control strategy over a rate-control strategy in managing atrial fibrillation (AF). Cardioversion and atrioventricular junctional ablation are forms of rhythm control and rate control, respectively. The numbers of cardioversions and atrioventricular junctional ablations performed at the University of Virginia and the Medical College of Virginia during the 52 months before AFFIRM and RACE results were released and the 21 months afterward were compared. From January 1998 to March 2002, monthly averages of 31 +/- 8 elective cardioversions and 6 +/- 3 atrioventricular junctional ablations were performed; from April 2002 to December 2003, the monthly averages were 21 +/- 6 cardioversions (p = 0.001) and 9 +/- 3 ablations (p = 0.001). AF management changed at these institutions shortly after the RACE and AFFIRM results were released.

Alteplase and ischaemic stroke: have new reviews of old data helped?

BACKGROUND

Thrombolysis for stroke is still not widely used as current recommendations restrict treatment to selected patients. In general, these are patients who can be assessed quickly by specialised stroke teams, have intracranial haemorrhage excluded by appropriate brain imaging, and are treated with alteplase (recombinant tissue plasminogen activator; rt-PA) within 3 h of symptom onset. There is, however, still much debate regarding the scope of treatment and the reorganisation of services required to support an effective service.

RECENT DEVELOPMENTS

Two recent publications have helped clarify some issues. The first was an individual-patient data meta-analysis of the alteplase trials. These analyses suggest treatment effects beyond the usual 3 h time window, but other than time to treatment no other factors influenced the effects of treatment. The second publication was a reanalysis of the original National Institute of Neurological Disorders and Stroke (NINDS) alteplase trial, done after criticism of the original study. The reanalysis confirmed that there was significant baseline imbalance of stroke severity between treatment and control groups in the NINDS trial, but established that this did not materially affect the positive results of the trial. However, the recording of blood pressure in the study was found to be inconsistent and therefore unsuitable for reanalysis. The previously published data on recommendations for blood-pressure control, arising from the NINDS trial, needs to be reconsidered in this light. Both studies included too few patients to provide reliable data on which clinical and radiological features influence the response to alteplase. WHERE NEXT?: The individual-patient data meta-analysis and reanalysis of the NINDS trial have probably exhausted the potential of previous trials to answer questions on the effects of thrombolysis. Further randomised trials comparing thrombolysis with control will be required to determine whether elderly people benefit from treatment or whether there are worthwhile benefits from alteplase beyond 3 h (and in such patients, whether advanced magnetic resonance imaging is an effective way to select those most likely to benefit). Various new approaches to reperfusion also require assessment in large-scale trials: new thrombolytic drugs, the combination of intravenous and intra-arterial thrombolytic drugs, combinations of thrombolytics with new antiplatelet agents, and augmentation of thrombolysis either with mechanical devices or with transcranial ultrasound.

Influences upon the diffusion of thrombolysis for acute myocardial infarction in England: case study

OBJECTIVES

To investigate the factors that influenced the adoption and diffusion of thrombolysis in acute myocardial infarction in England and to verify usage data from 1981 to 2001.

METHODS

Survey of cardiologists in England using a pre-prepared time line of historical events and a plot of thrombolysis diffusion since 1981. The cardiologists were divided into three groups that were provided with (i) the time line only, (ii) the diffusion curve only, and (iii) the time line and the diffusion curve.

RESULTS

The GISSI and ISIS-2 clinical trials were perceived to have had a significant influence upon the initial diffusion of thrombolysis in England occurring over the 3 years after launch. Other positive influences included the initial listing in the national formulary, the change to administration in emergency departments, the rise in evidence-based medicine, and production of national guidance.

CONCLUSIONS

Although it is apparent that the overall influences on adoption and diffusion of thrombolysis were multiple; clinical trials, service developments, and national guidelines all were judged to have played a part. The GISSI and ISIS-2 clinical trials were confirmed as the major influence on initial adoption.

Guiding the design and selection of interventions to influence the implementation of evidence-based practice: an experimental simulation of a complex intervention trial

A consistent finding in health services research is the report of uneven uptake of research findings. Implementation trials have a variable record of success in effectively influencing clinicians' behaviour. A more systematic approach may be to conduct Intervention Modelling Experiments before service-level trials, examining intervention effects on 'interim endpoints' representing clinical behaviour, derived from empirically supported psychological theories. The objectives were to: (1) Design Intervention Modelling Experiments by backward engineering a 'real-world' randomised controlled trial (NEXUS); (2) examine the applicability of psychological theories to clinical decision-making; (3) explore whether psychological theories can illuminate how interventions achieve their effects. A 2 x 2 factorial randomised controlled trial was designed with pre- and post-intervention data collection by postal questionnaire surveys. The first survey was used to generate feedback data and the interventions were delivered in the second survey. General medical practitioners (GPs) in England and Scotland participated. First survey respondents were randomised twice to receive or not audit and feedback and educational reminder messages. The main outcome measures included behavioural intention (general plan to refer for lumbar X-rays) and simulated behaviour (specific, scenario-based, decisions to refer for lumbar X-ray). Predictors were attitude, subjective norm, perceived behavioural control (theory of planned behaviour), self-efficacy (social cognitive theory) and decision difficulty. Both interventions significantly influenced simulated behaviour, but neither influenced behavioural intention. There were no interaction effects. All theoretically derived cognitions significantly predicted simulated behaviour. Only subjective norm was not predictive of behavioural intention. The effect of audit and feedback on simulated behaviour was mediated through perceived behavioural control. The results of this study suggest that Intervention Modelling Experiments, using psychological models to help isolate mediators of clinical decision-making, may be a means of developing more potent interventions, and selecting implementation interventions with a greater likelihood of success in a service-level randomised controlled trial.

Diffusion of thrombolysis for acute myocardial infarction from 1981 to 2000 in England: Trend analysis and comparison with need

Objectives: To describe the adoption and take up of thrombolytic agents for acute myocardial infarction since 1980 in England and compare use with the estimated ceiling of need.

Methods: Data on national sales and use of thrombolysis since 1980 (supplied by IMS Health) was used to draw an adoption and diffusion curve. The epidemiological ceiling of acute myocardial infarction, from hospital activity statistics, was modified to an estimated clinical need by accounting for diagnostic difficulty and contraindications using information from published surveys of thrombolysis use in the United Kingdom.

Results: There was a rapid uptake of thrombolytic agents in the first 2 years after availability in 1987, then a plateau, followed by a rise to a peak use in 1995. The shortfall in doses resulting from the difference between estimated ceiling of clinical need and doses purchased and provided in the 14 years since availability is estimated as 167,800 (95 percent confidence range 94,000 to 241,700).

Conclusions: Although there was a rapid initial uptake of thrombolysis in England, usage took 8 years to reach the ceiling of clinical need of 65 percent of patients with acute myocardial infarction, with many patients missing the opportunity to benefit. Monitoring of uptake of innovations known to be cost-effective is required to identify those developments that need additional stimulus for change to ensure that patients do not miss out on the opportunity to benefit.

Bridging the gap between therapeutic research results and physician prescribing decisions: knowledge transfer, a prerequisite to knowledge translation

BACKGROUND

A wide gap continues to exist between available therapeutic research results and physician's prescribing. Numerous explanations account for this gap, but one central reason is the difficulty in transferring comprehensive research information to practicing clinicians. This problem arises from information overload and the growing complexity of research findings. We propose a multistep process that can be used to develop systems to bridge this information/prescription gap. The steps include: comprehensively collecting and summarizing clinical trial reports, scoring and ranking these according to their level of evidence, exploring and synthesizing the data using meta-analyses, summarizing these results, representing them in an easily understandable form, and transmitting the overview findings to prescribers at the time they need them.

DISCUSSION

This ambitious endeavor is needed to ensure that prescribers have access to pertinent research results for use in their prescription decisions. We demonstrate in this article that there are no theoretical or technical obstacles to make the proposed system workable.