Partnering with survivors & families to determine research priorities for adult out-of-hospital cardiac arrest: A James Lind Alliance Priority Setting Partnership

BACKGROUND

Research priority setting in health care has historically been done by expert health care providers and researchers and has not involved patients, family or the public. Survivors & family members have been particularly absent from this process in the field of resuscitation research and specifically adult out of hospital cardiac arrest (OHCA). As such, we sought to conduct a priority setting exercise in partnership with survivors, lay responders and their families in order to ensure that their priorities were visible. We partnered with the James Lind Alliance (UK) and used their commonly used consensus methodology for Public Priority Setting Partnerships (PSPs) to identify research priorities that reflected the perspectives of all stakeholders.

METHODS

We used two rounds of public and health care professional surveys to create the initial priority lists. The initial survey collected open-ended questions while the second round consolidated the list of initial questions into a refined list for prioritization. This was done by reviewing existing evidence and thematic categorization by the multi-disciplinary steering committee. An in-person consensus workshop was conducted to come to consensus on the top ten priorities from all perspectives. The McMaster PPEET tool was used to measure engagement.

RESULTS

The initial survey yielded more than 425 responses and 1450 "questions" from survivors and family members (18%), lay responders, health care providers and others. The second survey asked participants to rank a short list of 125 questions. The final top 25 questions were brought to the in-person meeting, and a top ten were selected through the JLA consensus process. The final list of top ten questions included how to improve the rate of lay responder CPR, what interventions used at the scene of an arrest can improve resuscitation and survival, how survival can be improved in rural areas of Canada, what resuscitation medications are most effective, what care patient's family members need, what post-discharge support is needed for survivors, how communication should work for everyone involved with a cardiac arrest, what factors best predict neurologically intact survival, whether biomarkers/genetic tests are effective in predicting OHCA and more research on the short and long-term psycho-social impacts of OHCA on survivors. The PPEET showed overwhelmingly positive results for the patient and family engagement experience during the final workshop.

CONCLUSIONS

This inclusive research priority setting provides essential information for those doing resuscitation research internationally. The results provide a guide for priority areas of research and should drive our community to focus on questions that matter to survivors and their families in our work. In particular the Canadian Resuscitation Outcomes Consortium will be incorporating the top ten list into its strategic plan for the future.

Impact of the pan-Canadian Oncology Drug Review on provincial concordance with respect to cancer drug funding decisions and time to funding

BACKGROUND

The pan-Canadian Oncology Drug Review (pcodr) was implemented in 2011 to address uneven drug coverage and lack of transparency with respect to the various provincial cancer drug review processes in Canada. We evaluated the impact of the pcodr on provincial decision concordance and time from Notice of Compliance (noc) to drug funding.

METHODS

In a retrospective review, Health Canada's Drug Product Database was used to identify new indications for cancer drugs between January 2003 and May 2014, and provincial formulary listings for drug-funding dates and decisions between 1 January 2003 and 31 December 2014 were retrieved. Multiple linear models and quantile regressions were used to evaluate changes in time to decision-making before and after the implementation of the pcodr. Agreement of decisions between provinces was evaluated using kappa statistics.

RESULTS

Data were available from 9 provinces (all Canadian provinces except Quebec), identifying 88 indications that represented 51 unique cancer drugs. Two provinces lacked available data for all 88 indications at the time of data collection. Interprovincial concordance in drug funding decisions significantly increased after the pcodr's implementation (Brennan-Prediger coefficient: 0.54 pre-pcodr vs. 0.78 post-pcodr; p = 0.002). Nationwide, the median number of days from Health Canada's noc date to the date of funding significantly declined (to 393 days from 522 days, p < 0.001). Exploratory analyses excluding provinces with incomplete data did not change the results.

CONCLUSIONS

After the implementation of the pcodr, greater concordance in cancer drug funding decisions between provinces and decreased time to funding decisions were observed.

Survival Analysis in the Presence of Competing Risks: The Example of Waitlisted Kidney Transplant Candidates

Competing events (or risks) preclude the observation of an event of interest or alter the probability of the event's occurrence and are commonly encountered in transplant outcomes research. Transplantation, for example, is a competing event for death on the waiting list because receiving a transplant may significantly decrease the risk of long-term mortality. In a typical analysis of time-to-event data, competing events may be censored or incorporated into composite end points; however, the presence of competing events violates the assumption of "independent censoring," which is the basis of standard survival analysis techniques. The use of composite end points disregards the possibility that competing events may be related to the exposure in a way that is different from the other components of the composite. Using data from the Scientific Registry of Transplant Recipients, this paper reviews the principles of competing risks analysis; outlines approaches for analyzing data with competing events (cause-specific and subdistribution hazards models); compares the estimates obtained from standard survival analysis, which handle competing events as censoring events; discusses the appropriate settings in which each of the two approaches could be used; and contrasts their interpretation.

HLA-DR and -DQ eplet mismatches and transplant glomerulopathy: a nested case-control study

We conducted a nested case-control study from a cohort of adult kidney transplant recipients to assess the risk of transplant glomerulopathy (TG) as a function of donor and recipient HLA-DR and -DQ incompatibility at the eplet level. Cases (n = 52) were defined as patients diagnosed with transplant glomerulopathy based on biopsies showing glomerular basement membrane duplication without immune complex deposition. Controls (n = 104) with a similar follow-up from transplantation were randomly selected from the remaining cohort. HLAMatchmaker was used to ascertain the number of DRB1/3/4/5, DQA1 and DQB1 related eplet mismatches (eplet load). Multivariable conditional logistic regression models demonstrated an increase in the odds of TG (odds ratios [OR] of 2.84 [95% confidence interval (CI): 1.03, 7.84] and 4.62 [95% CI: 1.51, 14.14]) in the presence of 27-43 and >43 HLA-DR + DQ related eplet mismatches versus <27 eplet mismatches, respectively. When the eplet load was modeled as a continuous variable, the OR for TG was 1.25 (95% CI: 1.04, 1.50) for every 10 additional HLA-DR + DQ eplet mismatches. Our study suggests that minimization of HLA-DR + DQ eplet mismatches may decrease the incidence of transplant glomerulopathy diagnosed by indication biopsies. The role of eplet immunogenicity/antigenicity as determinants of allograft outcomes requires further study.

Vascular and upper gastrointestinal effects of non-steroidal anti-inflammatory drugs: meta-analyses of individual participant data from randomised trials

BACKGROUND

The vascular and gastrointestinal effects of non-steroidal anti-inflammatory drugs (NSAIDs), including selective COX-2 inhibitors (coxibs) and traditional non-steroidal anti-inflammatory drugs (tNSAIDs), are not well characterised, particularly in patients at increased risk of vascular disease. We aimed to provide such information through meta-analyses of randomised trials.

METHODS

We undertook meta-analyses of 280 trials of NSAIDs versus placebo (124,513 participants, 68,342 person-years) and 474 trials of one NSAID versus another NSAID (229,296 participants, 165,456 person-years). The main outcomes were major vascular events (non-fatal myocardial infarction, non-fatal stroke, or vascular death); major coronary events (non-fatal myocardial infarction or coronary death); stroke; mortality; heart failure; and upper gastrointestinal complications (perforation, obstruction, or bleed).

FINDINGS

Major vascular events were increased by about a third by a coxib (rate ratio [RR] 1·37, 95% CI 1·14-1·66; p=0·0009) or diclofenac (1·41, 1·12-1·78; p=0·0036), chiefly due to an increase in major coronary events (coxibs 1·76, 1·31-2·37; p=0·0001; diclofenac 1·70, 1·19-2·41; p=0·0032). Ibuprofen also significantly increased major coronary events (2·22, 1·10-4·48; p=0·0253), but not major vascular events (1·44, 0·89-2·33). Compared with placebo, of 1000 patients allocated to a coxib or diclofenac for a year, three more had major vascular events, one of which was fatal. Naproxen did not significantly increase major vascular events (0·93, 0·69-1·27). Vascular death was increased significantly by coxibs (1·58, 99% CI 1·00-2·49; p=0·0103) and diclofenac (1·65, 0·95-2·85, p=0·0187), non-significantly by ibuprofen (1·90, 0·56-6·41; p=0·17), but not by naproxen (1·08, 0·48-2·47, p=0·80). The proportional effects on major vascular events were independent of baseline characteristics, including vascular risk. Heart failure risk was roughly doubled by all NSAIDs. All NSAID regimens increased upper gastrointestinal complications (coxibs 1·81, 1·17-2·81, p=0·0070; diclofenac 1·89, 1·16-3·09, p=0·0106; ibuprofen 3·97, 2·22-7·10, p<0·0001; and naproxen 4·22, 2·71-6·56, p<0·0001).

INTERPRETATION

The vascular risks of high-dose diclofenac, and possibly ibuprofen, are comparable to coxibs, whereas high-dose naproxen is associated with less vascular risk than other NSAIDs. Although NSAIDs increase vascular and gastrointestinal risks, the size of these risks can be predicted, which could help guide clinical decision making.

FUNDING

UK Medical Research Council and British Heart Foundation.

Feasibility, limits and problems of clinical studies in Intensive Care Unit

In critical care medicine there is still a paucity of evidence on how to manage most of the clinical problems commonly encountered in critically ill patients. Randomized controlled trials (RCTs) are the most powerful instruments to evaluate the efficacy of a therapeutic intervention and to generate evidence for clinical practice. Unfortunately, the design and conduct of RCTs in our field are particularly complicated, because of some intrinsic and structural problems (e.g. lack of reliable nosography, concomitant use of different therapies, problems in the definition of end-points besides mortality) that will be discussed in this review. Further challenges are represented by the lack of tradition of large ICU networks, difficulties in linking or integrating physiologic and therapeutic objectives in designing clinical protocols, scarcity of independent or non-profit funds. A particularly stimulating opportunity of development is represented also by the relationship of critical care to EBM. Because of the above problems, metanalyses could be less informative than in other areas of medicine, as they are based on few trials which are often contradictory and of unsatisfactory quality. Few suggestions are formulated which could help looking forwards.

Anti-fibrinolytic use for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood have led to the development of a range of interventions to minimise blood loss during major surgery. Anti-fibrinolytic drugs are widely used, particularly in cardiac surgery and previous reviews have found them to be effective in reducing blood loss and the need for transfusion. Recently, questions have been raised regarding the comparative performance of the drugs and the safety of the most popular agent, aprotinin.

OBJECTIVES

To assess the comparative effects of the anti-fibrinolytic drugs aprotinin, tranexamic acid (TXA), and epsilon aminocaproic acid (EACA) on blood loss during surgery, the need for red blood (RBC) transfusion, and adverse events, particularly vascular occlusion, renal dysfunction, and death.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, and the internet. References in identified trials and review articles were checked and trial authors were contacted to identify any additional studies. The searches were last updated in July 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of anti-fibrinolytic drugs in adults scheduled for non-urgent surgery. Eligible trials compared anti-fibrinolytic drugs with placebo (or no treatment), or with each other.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

This review summarises data from 211 RCTs that recruited 20,781 participants. Data from placebo/inactive controlled trials, and from head-to-head trials suggest an advantage of aprotinin over the lysine analogues TXA and EACA in terms of operative blood loss, but the differences were small. Aprotinin reduced the probability of requiring RBC transfusion by a relative 34% (relative risk [RR] 0.66, 95% confidence interval [CI] 0.61 to 0.71). The RR for RBC transfusion with TXA was 0.61 (95% CI 0.54 to 0.69) and it was 0.75 (95% CI 0.58 to 0.96) with EACA. When the pooled estimates from the head-to-head trials of the two lysine analogues were combined and compared to aprotinin alone, aprotinin appeared superior in reducing the need for RBC transfusion: RR 0.83 (95% CI 0.69 to 0.99). Aprotinin reduced the need for re-operation due to bleeding: RR 0.48 (95% CI 0.35 to 0.68). This translates into an absolute risk reduction of just under 3% and a number needed-to-treat (NNT) of 37 (95% CI 27 to 56). Similar trends were seen with TXA and EACA, but the data were sparse and the differences failed to reach statistical significance. The blood transfusion data were heterogeneous and funnel plots indicate that trials of aprotinin and the lysine analogues may be subject to publication bias. Evidence of publication bias was not observed in trials reporting re-operation rates. Adjustment for these effects reduced the magnitude of estimated benefits but did not negate treatment effects. However, the apparent advantage of aprotinin over the lysine analogues was small and may be explained by publication bias and non-equivalent drug doses. Aprotinin did not increase the risk of myocardial infarction (RR 0.92, 95% CI 0.72 to 1.18), stroke (RR 0.76, 95% CI 0.35 to 1.64) renal dysfunction (RR 1.16, 95% CI 0.79 to 1.70) or overall mortality (RR 0.90, 95% CI 0.67 to 1.20). The analyses of myocardial infarction and death included data from the majority of subjects recruited into the clinical trials of aprotinin. However, under-reporting of renal events could explain the lack of effect seen with aprotinin. Similar trends were seen with the lysine analogues but data were sparse. These results conflict with the results of recently published non-randomised studies.

AUTHORS' CONCLUSIONS

Anti-fibrinolytic drugs provide worthwhile reductions in blood loss and the need for allogeneic red cell transfusion. Based on the results of randomised trials their efficacy does not appear to be offset by serious adverse effects. In most circumstances the lysine analogues are probably as effective as aprotinin and are cheaper; the evidence is stronger for tranexamic acid than for aminocaproic acid. In high risk cardiac surgery, where there is a substantial probability of serious blood loss, aprotinin may be preferred over tranexamic acid. Aprotinin does not appear to be associated with an increased risk of vascular occlusion and death, but the data do not exclude an increased risk of renal failure. There is no need for further placebo-controlled trials of aprotinin or lysine analogues in cardiac surgery. The principal need is for large comparative trials to assess the relative efficacy, safety and cost-effectiveness of anti-fibrinolytic drugs in different surgical procedures.

Use of vascular risk-modifying medications for diabetic patients differs between physician specialties

AIMS

Although heart disease and stroke are the underlying causes of death in most people with diabetes, vascular risk modification targets are frequently not met. This study examined whether vascular risk-modifying medication utilization for diabetic patients differed among physician specialties.

METHODS

A population-based study using administrative data from 105 715 people aged >/= 65 years with newly diagnosed diabetes in Ontario between 1994 and 2001. The receipt of antihypertensive and lipid-lowering drugs was compared between patients who had regular care from endocrinologists, internists/geriatricians and family physicians. Hierarchical logistic regression adjusted for patient-level differences, physician-level differences and patient clustering within physicians.

RESULTS

Only two-thirds of patients received antihypertensive drugs and about one-quarter received lipid-lowering drugs. Compared with patients of family physicians, the adjusted odds ratios for antihypertensive drug use were 1.27 [95% confidence interval (CI) 1.16, 1.38] for patients of internists/geriatricians and 1.03 (95% CI 0.94, 1.12) for patients of endocrinologists. For lipid-lowering drugs, the odds ratios were 1.20 (95% CI 1.11, 1.30) for patients of internists/geriatricians and 1.58 (95% CI 1.42, 1.76) for patients of endocrinologists.

CONCLUSIONS

Despite recommendations to use vascular risk-modifying medication for most older people with diabetes, many patients were not receiving these medications. Medication utilization differed between physician specialties, with family physicians having the lowest rates of use. Notably, although blood pressure control has the greatest evidence of benefit and is cost-saving, endocrinologists did not use antihypertensive drugs more often than family physicians after adjustment for other differences.

A decision aid for autologous pre-donation in cardiac surgery--a randomized trial

OBJECTIVES

The objective of this randomized, controlled study was to determine the usefulness of a decision aid on pre-donation of autologous blood before elective open heart surgery.

METHODS

The decision aid (DA) group received a tape and booklet which described the options for peri-operative transfusion in detail. The no decision aid (NDA) group received information usually given to patients about autologous donation.

RESULTS

A total of 120 patients were randomized. The DA group rated themselves better prepared for decision making and showed significant improvements in knowledge (p = 0.001) and realistic risk perceptions (p = 0.001). In both groups there was an increase in the proportion of patients choosing allogeneic blood between baseline and follow-up (p = 0.001). Patients in the DA group were significantly more satisfied with the amount of information they received, how they were treated and with the decision they made, than patients in the NDA group.

CONCLUSION

The decision aid is useful in preparing patients for decision making.

PRACTICE IMPLICATIONS

The next stage is to explore strategies to make it available to all appropriate patients.

Long-term pulmonary function abnormalities and survival after allogeneic marrow transplantation

We studied long-term pulmonary function testing (PFT) in a retrospective cohort of 6-month survivors of allogeneic marrow transplant (BMT) between 1980 and 1997. Of 593 patients, 73, 71 and 65% had adequate data to assess for obstruction, restriction and diffusion impairments respectively. Over 5 years, mean declines in 1-s forced expiratory volume/forced vital capacity (FEV1/FVC), total lung capacity (TLC) and diffusion were 4, 7 and 17%, respectively. TLC and diffusion tended to subsequently increase. In all, 6, 12 and 35% of patients met criteria for obstruction, restriction and impaired diffusion, respectively. Obstruction was less common in recent transplants (5 vs 15%, P=0.004), while restriction and diffusion impairment rates remained stable. There was significantly greater mortality with obstruction (HR 2.0 (1.04-3.95)), and a nonstatistically significant higher mortality rate with restriction (HR 1.6 (0.95-2.75)), but not with impaired diffusion (HR=0.99 (0.65-1.50)). cGVHD (OR 16.7 (2.2-129.8)) and busulfan (OR 2.9 (1.01-8.24)) were associated with obstruction. Marrow from nonsibling or mismatched donors (OR 4.9 (2.2-10.7)) was associated with restriction. In summary, after BMT, decreased diffusion capacity is common and benign; obstruction has decreased in frequency, is rare without cGVHD, and is associated with mortality; nonsibling and mismatched donor are risk factors for restriction.

Pulmonary function abnormalities after allogeneic marrow transplantation: a systematic review and assessment of an existing predictive instrument

Pulmonary function testing (PFT) is used to characterize non-infectious pulmonary complications after allogeneic BMT. Identifying high-risk patients could facilitate preventive or early therapeutic measures. The objectives of the study were first, to review available data on PFT changes after BMT and second, to validate a previously published predictive index for PFT obstruction in patients transplanted at one center. For the systematic review, frequency, severity and time course of PFT changes after BMT and for the validation study, retrospective cohort comparing predicted with observed PFT, and calculation of indices of predictive accuracy were summarized. The validation study involved 434 patients from Princess Margaret Hospital, Toronto, Canada, who received their first BMT between 1980 and 1997, survived for at least 6 months and had adequate PFT follow-up. The systematic review included 20 studies. After BMT, decreased diffusion and total lung capacity were common and partially reversible. Obstruction was less common. The validation study of a previously published index, performed in 434 patients, found a sensitivity and specificity of 48% and 68% for identifying patients who develop obstruction. We concluded that PFT changes after BMT are common. A published predictive index is not sufficiently accurate to identify high-risk patients for potential preventive or early therapeutic strategies.

Meta-analysis of randomised controlled trials of the effectiveness of antiarrhythmic agents at promoting sinus rhythm in patients with atrial fibrillation

OBJECTIVE

To conduct a meta-analysis of randomised controlled trials to estimate the effectiveness of antiarrhythmic drugs at promoting sinus rhythm in patients with atrial fibrillation.

DESIGN

Articles were identified by using a comprehensive search of English language papers indexed in Medline from 1966 to August 2001. For the outcomes of sinus rhythm and death, a random effects model was used to model repeated assessments within a study at different time points.

SETTING

Emergency departments and ambulatory clinics.

PATIENTS

Patients with atrial fibrillation.

INTERVENTIONS

Antiarrhythmic agents grouped according to their Vaughan-Williams class.

MAIN OUTCOME MEASURES

Sinus rhythm and mortality.

RESULTS

91 articles met a priori criteria for inclusion in the analysis. Median duration of follow up was one day (range 0.04-1096, mean (SD) 46 (136) days). The median proportion of patients in sinus rhythm at follow up was 55% (range 0-100%) and 32% (range 0-90%) receiving active treatment and placebo, respectively. Median survival was 99% (range 55-100%) and 99% (range 55-100%). Compared with placebo, the following drug classes were associated with increased sinus rhythm at follow up: IA (treatment difference 21.5%, 95% confidence interval (CI) 16.3% to 26.8%); IC (treatment difference 33.1%, 95% CI 23.3% to 42.9%); and III (treatment difference 17.4%, 95% CI 11.5% to 23.3%). Class IC drugs were associated with increased sinus rhythm at follow up compared with class IV drugs (treatment difference 43.2%, 95% CI 11.5% to 75.0%). There was no significant difference in mortality between any drug classes.

CONCLUSIONS

Class IA, IC, and III drugs are associated with increased sinus rhythm at follow up compared with placebo. It is unclear whether any antiarrhythmic drug class is associated with increased or decreased mortality.

The future of evidence-based medicine

Evidence-based medicine (EBM) stresses the examination of evidence from clinical research as an important basis for the practice of medicine. EBM is an approach that is intuitively reasonable, and is increasingly taught in medical schools and incorporated into practice. Although it is often not feasible for busy clinicians to find and appraise original research themselves, EBM is now frequently used to develop clinical practice guidelines. However, there are often 'grey areas' in the interpretation of the evidence, some of which are discussed in this paper. Clinical medicine can be complex, and EBM will never provide easy answers to difficult problems, which means that there will always be an art to clinical medicine. As well, EBM is practised in complex, semirational, constantly changing health care systems, which sometimes actually establish barriers to the incorporation of evidence into practice.

The use of technologies to decrease peri-operative allogenic blood transfusion: results of practice variation in Israel

BACKGROUND

Concern about the side effects of allogeneic blood transfusion has led to increased interest in methods of minimizing peri-operative transfusion. Technologies to minimize allogeneic transfusion include drugs such as aprotinin, desmopressin, tranexamic acid and erythropoietin, and techniques such as acute normovolemic hemodilution, cell salvage and autologous pre-donation.

OBJECTIVE

To survey the current use in Israel of these seven technologies to minimize allogeneic blood transfusion.

METHODS

Our survey was conducted in 1996-97 in all hospitals in Israel with more than 50 beds and at least one of the following departments: cardiac or vascular surgery, orthopedics, or urology. All departments surveyed were asked: a) whether the technologies were currently being used or not, b) the degree of use, and c) the factors influencing their use and non-use. The survey was targeted at the heads of these departments.

RESULTS

Pharmaceuticals to reduce allogeneic blood transfusion were used in a much higher proportion in cardiac surgery departments than in the other three departments. Pre-operative blood donation was used in few of the cardiac, urologic and vascular surgery departments compared to its moderate use in orthopedic departments. The use of acute normovolemic hemodilution was reported in a majority of the cardiac departments only. Moderate use of cell salvage was reported in all departments except urology where it was not used at all.

CONCLUSION

There is considerable practice variation in the use of technologies to minimize exposure to peri-operative allogeneic blood transfusion in Israel.

How well is the clinical importance of study results reported? An assessment of randomized controlled trials

BACKGROUND

The interpretation of the results of randomized controlled trials (RCTs) has traditionally emphasized statistical significance rather than clinical importance. Our aim was to assess the quality of reporting of factors related to clinical importance in a sample of published RCTs.

METHODS

A random sample of 27 (of a total of 266) RCTs published in 5 major medical journals over a 1-year period were reviewed by 4 independent reviewers for factors considered important in the interpretation of the clinical importance of study results: identification of a clearly defined primary outcome, reporting of the expected difference between groups used in the calculation of sample size (the delta value) and whether it was based on the minimal clinically important difference of the intervention, the statistical significance of the results, presentation of pertinent confidence intervals, and the authors' interpretation of the clinical importance of the results.

RESULTS

Twenty-two of 27 (81%) articles explicitly reported a single primary outcome. Of the 20 articles that included a sample size calculation, 18 (90%) reported a delta value. Two of the 18 (11%) articles explicitly stated that the delta value was chosen to reflect the minimal clinically important difference of the intervention. For the primary outcomes, confidence intervals surrounding the point estimates of the efficacy of the interventions were reported in 11 of 27 (41%) studies. The study results were interpreted from the perspective of clinical importance in 20 of 27 (74%) of the articles. Of these 20 reports, 5 (25%) provided justification for their clinical interpretation of the results.

INTERPRETATION

Authors of RCTs published in major general medical and internal medicine journals do not consistently provide their own interpretation of the clinical importance of their results, and they often do not provide sufficient information to allow readers to make their own interpretation.

The Canadian C-spine rule for radiography in alert and stable trauma patients

CONTEXT

High levels of variation and inefficiency exist in current clinical practice regarding use of cervical spine (C-spine) radiography in alert and stable trauma patients.

OBJECTIVE

To derive a clinical decision rule that is highly sensitive for detecting acute C-spine injury and will allow emergency department (ED) physicians to be more selective in use of radiography in alert and stable trauma patients.

DESIGN

Prospective cohort study conducted from October 1996 to April 1999, in which physicians evaluated patients for 20 standardized clinical findings prior to radiography. In some cases, a second physician performed independent interobserver assessments.

SETTING

Ten EDs in large Canadian community and university hospitals.

PATIENTS

Convenience sample of 8924 adults (mean age, 37 years) who presented to the ED with blunt trauma to the head/neck, stable vital signs, and a Glasgow Coma Scale score of 15.

MAIN OUTCOME MEASURE

Clinically important C-spine injury, evaluated by plain radiography, computed tomography, and a structured follow-up telephone interview. The clinical decision rule was derived using the kappa coefficient, logistic regression analysis, and chi(2) recursive partitioning techniques.

RESULTS

Among the study sample, 151 (1.7%) had important C-spine injury. The resultant model and final Canadian C-Spine Rule comprises 3 main questions: (1) is there any high-risk factor present that mandates radiography (ie, age >/=65 years, dangerous mechanism, or paresthesias in extremities)? (2) is there any low-risk factor present that allows safe assessment of range of motion (ie, simple rear-end motor vehicle collision, sitting position in ED, ambulatory at any time since injury, delayed onset of neck pain, or absence of midline C-spine tenderness)? and (3) is the patient able to actively rotate neck 45 degrees to the left and right? By cross-validation, this rule had 100% sensitivity (95% confidence interval [CI], 98%-100%) and 42.5% specificity (95% CI, 40%-44%) for identifying 151 clinically important C-spine injuries. The potential radiography ordering rate would be 58.2%.

CONCLUSION

We have derived the Canadian C-Spine Rule, a highly sensitive decision rule for use of C-spine radiography in alert and stable trauma patients. If prospectively validated in other cohorts, this rule has the potential to significantly reduce practice variation and inefficiency in ED use of C-spine radiography.

Canadian CT head rule study for patients with minor head injury: methodology for phase II (validation and economic analysis)

Prospective validation on a new set of patients is an essential test of a new decision rule. However, many clinical decision rules are not prospectively assessed to determine their accuracy, reliability, clinical sensibility, or potential impact on practice. This validation process is important because many statistically derived rules or guidelines do not perform well when tested in a new population. The methodologic standards for a validation study are similar to those described in the article on phase I for derivation studies in the August 2001 issue of Annals of Emergency Medicine. The goal of phase II is to prospectively assess the accuracy, reliability, and acceptability of the decision rule in a new set of patients with minor head injury. This will determine the clinical utility of the rule and is essential if such a rule is to be widely adopted into clinical practice.

Differences in treatment preferences between persons who enrol and do not enrol in a clinical trial

OBJECTIVE

To quantitatively compare preferences for treatment between persons who enrolled in a randomized controlled trial (RCT) and those who were eligible but chose not to enrol.

INTERVENTIONS

Participants' thresholds for treatment were determined using a probability trade-off technique. Pertinent health states were described. If not taking Aspirin, the probabilities of stroke, myocardial infarction (MI), and major bleeding were given. Given the risks and benefits of chronic Aspirin therapy, a systematic approach was used to determine patients' thresholds for treatment (the smallest reduction in stroke or MI risk of which patients were willing to take Aspirin).

RESULTS

Of 54 participants, 42 enrolled in the RCT, and 12 did not. Compared with persons who enrolled, those who did not enrol required significantly greater increments in treatment benefit to be willing to take Aspirin.

CONCLUSIONS

This study shows differences in thresholds for treatment between persons who enrolled in a clinical trial and those who chose not to. Such attitudinal differences may lead to difficulty in the interpretation of clinical trials, especially those using health-related quality-of-life measures. More studies are needed to determine whether the attitudinal differences affect the generalization of results from clinical trials.

The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation)

Head injuries are among the most common types of trauma seen in North American emergency departments, with an estimated 1 million cases seen annually. "Minor" head injury (sometimes known as "mild") is defined by a history of loss of consciousness, amnesia, or disorientation in a patient who is conscious and talking, that is, with a Glasgow Coma Scale score of 13 to 15. Although most patients with minor head injury can be discharged without sequelae after a period of observation, in a small proportion, their neurologic condition deteriorates and requires neurosurgical intervention for intracranial hematoma. The objective of the Canadian CT Head Rule Study is to develop an accurate and reliable decision rule for the use of computed tomography (CT) in patients with minor head injury. Such a decision rule would allow physicians to be more selective in their use of CT without compromising care of patients with minor head injury. This paper describes in detail the rationale, objectives, and methodology for Phase I of the study in which the decision rule was derived. [Stiell IG, Lesiuk H, Wells GA, McKnight RD, Brison R, Clement C, Eisenhauer MA, Greenberg GH, MacPhail I, Reardon M, Worthington J, Verbeek R, Rowe B, Cass D, Dreyer J, Holroyd B, Morrison L, Schull M, Laupacis A, for the Canadian CT Head and C-Spine Study Group. The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation). Ann Emerg Med. August 2001;38:160-169.]

A policy analysis of major decisions relating to Creutzfeldt-Jakob disease and the blood supply

Creutzfeldt-Jakob disease (CJD) is the first major challenge that the blood system has faced since the completion of the Krever inquiry in 1997. We report the results of a detailed policy analysis comparing 2 CJD-related decisions: a 1995 recall of blood from a donor with classic CJD and the 1999 decision to defer donations from individuals with a 6-month travel history to the UK between 1980 and 1996 due to concerns related to variant CJD. Overall, we observed that decision-making improved significantly from 1995 to 1999. In 1998/99 the potential threat of variant CJD was identified at an early stage, and a systematic risk assessment process was initiated. Decision-making was consultative and involved consumers. However, the perception existed that further improvement could take place in the areas of transparency of process and interaction of organizations. We observed that the presence of a second operator had an important impact on decision-making in 1998/99.

Use of statins and the subsequent development of deep vein thrombosis

BACKGROUND

Some of the benefit of statins for the prevention of cardiovascular disease may be due to their antithrombotic properties. Little is known about the effect of these drugs on the development of deep vein thrombosis.

MATERIALS AND METHODS

We conducted a retrospective cohort study over an 8-year period by linking Ontario provincial health care administrative databases covering more than 1.4 million Ontario residents aged 65 years or older. We excluded those with a documented history of atherosclerosis, venous thromboembolism, or cancer within 36 months prior to study enrollment, as well as those prescribed warfarin sodium within 12 months before enrollment. In the primary cohort, we evaluated the subsequent risk of deep vein thrombosis (DVT) among men and women prescribed thyroid replacement therapy, nonstatin lipid-lowering agents, or statins. A second cohort of women only was evaluated in a similar fashion, but estrogen use was added as a third comparison drug group.

RESULTS

There were 125 862 men and women in the primary cohort. After adjusting for age; sex; prior hospitalization; newly diagnosed cancer; or prescribed aspirin, warfarin, or estrogen, statin users (n = 77 993) had an associated decreased risk of DVT relative to those prescribed thyroid replacement therapy (n = 35 978) (adjusted hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.69-0.87). Compared with thyroid replacement therapy, users of nonstatin lipid-lowering agents (n = 11 891) did not seem to be at lower risk for deep vein thrombosis (HR, 0.97; 95% CI, 0.79-1.18). In the secondary cohort of 89 508 women, after adjusting for age, prior hospitalization, newly diagnosed cancer, or prescribed aspirin or warfarin, estrogen users (n = 29 165) had an associated increased risk for DVT compared with those receiving thyroid replacement therapy (n = 22 118) (HR, 1.16; 95% CI, 1.01-1.33), while statin users had an associated decreased risk (HR, 0.68; 95% CI, 0.59-0.79). Nonstatin lipid-lowering agents (n = 5155) were not associated with a reduced risk of DVT compared with thyroid replacement therapy (HR, 0.84; 95% CI, 0.63-1.12).

CONCLUSION

Among selected individuals aged 65 years or older, statins were associated with a 22% relative risk reduction in the risk of DVT. A randomized clinical trial is needed to evaluate the efficacy of statins for the primary and secondary prevention of DVT.

The Canadian CT Head Rule for patients with minor head injury

BACKGROUND

There is much controversy about the use of computed tomography (CT) for patients with minor head injury. We aimed to develop a highly sensitive clinical decision rule for use of CT in patients with minor head injuries.

METHODS

We carried out this prospective cohort study in the emergency departments of ten large Canadian hospitals and included consecutive adults who presented with a Glasgow Coma Scale (GCS) score of 13-15 after head injury. We did standardised clinical assessments before the CT scan. The main outcome measures were need for neurological intervention and clinically important brain injury on CT.

FINDINGS

The 3121 patients had the following characteristics: mean age 38.7 years); GCS scores of 13 (3.5%), 14 (16.7%), 15 (79.8%); 8% had clinically important brain injury; and 1% required neurological intervention. We derived a CT head rule which consists of five high-risk factors (failure to reach GCS of 15 within 2 h, suspected open skull fracture, any sign of basal skull fracture, vomiting >2 episodes, or age >65 years) and two additional medium-risk factors (amnesia before impact >30 min and dangerous mechanism of injury). The high-risk factors were 100% sensitive (95% CI 92-100%) for predicting need for neurological intervention, and would require only 32% of patients to undergo CT. The medium-risk factors were 98.4% sensitive (95% CI 96-99%) and 49.6% specific for predicting clinically important brain injury, and would require only 54% of patients to undergo CT.

INTERPRETATION

We have developed the Canadian CT Head Rule, a highly sensitive decision rule for use of CT. This rule has the potential to significantly standardise and improve the emergency management of patients with minor head injury.

Evaluation of a decision aid for patients considering autologous blood donation before open-heart surgery

BACKGROUND

Patients undergoing open-heart surgery frequently require one or more blood transfusions. Because of the risks of receiving blood from volunteer donors, some patients choose to donate their own blood before surgery. This reduces their risk of exposure to volunteer-donated blood, but it increases their chance of receiving any transfusion, either of self-donated or volunteer-donated blood. Also, preoperative hemoglobin levels tend to be lower in patients who donate their own blood, and surgeons may be more likely to give transfusions to patients with self-donated blood. To help patients decide whether to donate their blood before surgery, we designed a decision aid comprising a booklet and audiotape and assessed its effectiveness.

METHODS

The 59 study subjects were a sample of consecutive patients referred to the Ottawa Heart Institute between Oct. 1, 1998, and Jan. 5, 1999, for future coronary artery bypass grafting, valve surgery or combined surgery. All were eligible to donate blood. Initial questionnaires were administered in the clinic by a physician or study nurse, and follow-up questionnaires were completed at home and mailed in after use of the decision aid. Outcome measures included patients' knowledge, values (importance ratings), preferences for transfusion methods, decisional conflict (the amount of uncertainty about the course of action to take), risk perception and acceptability of the decision aid.

RESULTS

Mean knowledge scores on a 15-item test increased from 67% correct responses before the decision aid to 85% correct responses after use of the aid (p < 0.001); the effect was similar when the patients were divided into subgroups according to education level. The number of patients favouring donating their own blood increased from 41 (69%) before to 45 (76%) after use of the aid. Nine (64%) of 14 initially uncertain patients preferred autologous donation after use of the aid. The overall mean score for decisional conflict was unchanged, at 1.7, which indicated a low level of uncertainty. Risk perception improved, from 0%-14% correct responses on an 8-item test before the aid to 18%-60% correct responses after use of the aid. The decision aid was acceptable to the majority of patients, and 95% indicated that they would recommend it to others.

INTERPRETATION

The decision aid improved knowledge and risk perceptions of blood donation and transfusion, and it helped uncertain patients to make choices.

Utilization of technologies to reduce allogeneic blood transfusion in the United States

Concern over safety of the blood supply has led to the use of technologies to reduce allogeneic blood transfusion. The objective of this research was to determine the utilization of these technologies in the United States. We evaluated the following techniques: preoperative autologous donation (PAD), cell salvage (CS) and acute normovolemic haemodilution (ANH); and the following pharmaceuticals: aprotinin (APR), epsilon-aminocaproic acid (EACA), tranexamic acid (TXA), desmopressin (DDAVP) and recombinant human erythropoietin (EPO). In 1997, we conducted a cross-sectional mail survey of service chiefs at 1000 US hospitals randomly selected and stratified by status as a provider of open-heart surgery, geographical location and hospital bed size. Sixty-nine per cent (690) of hospitals responded to at least one of the four surveys sent to each hospital. Hospitals reported use of techniques more than pharmaceuticals (P < 0.001); PAD (83%, n = 206) and CS (82% n = 420) were used most frequently. Lack of familiarity was the most common reason cited for infrequent use of pharmaceuticals. Organizational characteristics (e.g. provision of open-heart surgery, size, geographical location, teaching status and type of hospital) were differentially associated with technology use. There is greater use of techniques than pharmaceuticals in US hospitals to reduce the need for allogeneic blood in the peri-operative setting. Providing open-heart surgery is strongly associated with the utilization of these technologies.

What should be included in meta-analyses? An exploration of methodological issues using the ISPOT meta-analyses

OBJECTIVE

To explore the impact of methodologic issues on the results of meta-analyses. The following issues were examined: the type of literature search strategy used; inclusion or exclusion of non-peer-reviewed studies; the inclusion or exclusion of non-English language publications; the effect of trial quality; and the inclusion or exclusion of non-placebo-controlled studies.

METHODS

The International Study of Perioperative Transfusion (ISPOT) meta-analyses were used to evaluate each of the methodologic issues. The 10 meta-analyses consisted of technologies to reduce the need for perioperative red blood cell transfusion. The number of trials for each of the meta-analyses varied from 2 to 45. Both EMBASE and MEDLINE searches were conducted, including the use of systematic search strategies.

RESULTS

MEDLINE identified the vast majority of trials. Alone, MEDLINE would have missed 8 studies compared to 10 for EMBASE. Use of the systematic search strategies greatly reduced the number of articles to be reviewed compared to open searches. Type of publication, country of study origin, inclusion of non-English publications, and trial quality had very little impact on the estimates of effect. The use of placebo versus open-label control affected the magnitude of the odds ratio for two of the meta-analyses. The results of the two meta-analyses were not statistically significant if only placebo-controlled trials were included.

CONCLUSIONS

While methodologic issues had very little impact on the ISPOT meta-analyses, further studies are needed in a variety of other clinical settings. Because MEDLINE, coupled with a review of the references in the identified trials, identified the vast majority of trials, one needs to consider the costs and benefits of searching EMBASE and the pursuance of unpublished and unindexed trials.

Awareness and use of the Ottawa ankle and knee rules in 5 countries: can publication alone be enough to change practice?

STUDY OBJECTIVES

We evaluate the international diffusion of the Ottawa Ankle and Knee Rules and determine emergency physicians' attitudes toward clinical decision rules in general.

METHODS

We conducted a cross-sectional, self-administered mail survey of random samples of 500 members each of the American College of Emergency Physicians, Canadian Association of Emergency Physicians, British Association for Accident and Emergency Medicine, Spanish Society for Emergency Medicine, and all members (n=1,350) of the French Speaking Society of Emergency Physicians, France. Main outcome measures were awareness of the Ottawa Ankle and Knee Rules, reported use of these rules, and attitudes toward clinical decision rules in general.

RESULTS

A total of 1,769 (57%) emergency physicians responded, with country-specific response rates between 49% (United States and France) and 79% (Canada). More than 69% of physicians in all countries, except Spain, were aware of the Ottawa Ankle Rules. Use of the Ottawa Ankle Rules differed by country with more than 70% of all responding Canadian and United Kingdom physicians reporting frequent use of the rules compared with fewer than one third of US, French, and Spanish physicians. The Ottawa Knee Rule was less well known and less used by physicians in all countries. Most physicians in all countries viewed decision rules as intended to improve the quality of health care (>78%), a convenient source of advice (>67%), and good educational tools (>61%). Of all physicians, those from the United States held the least positive attitudes toward decision rules.

CONCLUSION

This constitutes the largest international survey of emergency physicians' attitudes toward and use of clinical decision rules. Striking differences were apparent among countries with regard to knowledge and use of decision rules. Despite similar awareness in the United States, Canada, and the United Kingdom, US physicians appeared much less likely to use the Ottawa Ankle Rules. Future research should investigate factors leading to differences in rates of diffusion among countries and address strategies to enhance dissemination and implementation of such rules in the emergency department.

Anti-fibrinolytic use for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood have prompted re-consideration of the use of allogeneic (blood from an unrelated donor) blood transfusion.

OBJECTIVES

To assess the effects of the anti-fibrinolytic drugs aprotinin, tranexamic acid, and epsilon aminocaproic acid, on peri-operative red blood cell (RBC) transfusion.

SEARCH STRATEGY

We searched MEDLINE (to May 1998), EMBASE (to December 1997), web sites of international health technology assessment agencies (to May 1998). References in identified trials and review articles were checked and authors contacted to identify any additional studies.

SELECTION CRITERIA

Randomised controlled trials of anti-fibrinolytic drugs in adults scheduled for non-urgent surgery.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data.

MAIN RESULTS

We found 61 trials of aprotinin (7027 participants). Aprotinin reduced the rate of RBC transfusion by a relative 30% (RR=0.70: 95%CI: 0.64 to 0.76). The average absolute risk reduction (ARR) was 20.4% (95%CI: 15.6% to 25.3%). On average, aprotinin use saved 1.1 units of RBC (95%CI: 0.69 to 1.47) in those requiring transfusion. Aprotinin also significantly reduced the need for re-operation due to bleeding (RR=0.40: 95%CI: 0.25 to 0.66). We found 18 trials of tranexamic acid (TXA) (1,342 participants). TXA reduced the rate of RBC transfusion by a relative 34% (RR=0.66: 95%CI: 0.54 to 0.81). This represented an ARR of 17.2% (95%CI: 8.7% to 25.7%). TXA use resulted in a saving of 1.03 units of RBC (95%CI: 0.67 to 1.39) in those requiring transfusion. We found four trials of epsilon aminocaproic acid (EACA) (208 participants). EACA use resulted in a statistically non-significant reduction in RBC transfusion (RR=0.48: 95%CI: 0.19 to 1.19). Comparisons between agents Eight trials made 'head-to-head' comparisons between TXA and aprotinin. There was no significant difference between the two drugs in the rate of RBC transfusion: RR=1.21 (95%CI: 0.83 to 1.76) for TXA compared to aprotinin. Adverse Effects Aprotinin did not seem to be associated with an excess risk of adverse effects, including thrombo-embolic events (thrombosis RR=0.64: 95%CI: 0.31 to 1.31) and renal failure (RR=1.19: 95%CI: 0.79 to 1.79). Fewer data were available for TXA and EACA.

REVIEWER'S CONCLUSIONS

From this review it appears that aprotinin reduces the need for red cell transfusion, and the need for re-operation due to bleeding, without serious adverse effects. However, there was significant heterogeneity in trial outcomes, and some evidence of publication bias. Similar trends were seen with TXA and EACA, although the data were rather sparse. The poor evaluation of these latter drugs is unfortunate as results suggest they may be equally as effective as aprotinin, but are significantly cheaper. The evidence reviewed here supports the use of aprotinin in cardiac surgery. Further small trials of this drug are not warranted. Future trials should be large enough to compare the efficacy and cost-effectiveness of aprotinin with that of TXA and EACA.

Desmopressin for minimising perioperative allogeneic blood transfusion

BACKGROUND

Public concerns regarding the safety of transfused blood have prompted re-consideration of the use of allogeneic (from an unrelated donor) red blood cell (RBC) transfusion, and a range of techniques designed to minimise transfusion requirements.

OBJECTIVES

To examine the evidence for the efficacy of desmopressin (1-deamino-8-D-arginine-vasopressin), in reducing perioperative blood loss and the need for red cell transfusion in patients who do not have congenital bleeding disorders.

SEARCH STRATEGY

Articles were identified by: computer searches of OVID MEDLINE, EMBASE, and Current Contents (to August 2000) and web sites of international health technology assessment agencies (to May 1998). References in the identified trials and review articles were checked and authors contacted to identify additional studies.

SELECTION CRITERIA

Randomised controlled parallel group trials in which adult patients, scheduled for non-urgent surgery, were randomised to DDAVP, or to a control group, who did not receive the intervention.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed using criteria proposed by Schulz et al. (1995) and Jadad et al. (1996). The principal outcomes were: the number of patients exposed to red cells, and the amount of blood transfused. Other clinical outcomes are detailed in the review.

MAIN RESULTS

Fourteen trials of DDAVP (N=1034) reported data on the proportion of patients exposed to allogeneic RBC transfusion. In subjects treated with DDAVP the relative risk of exposure to peri-operative allogeneic blood transfusion was 0.98 (95%CI: 0.88 to 1.10) compared with control. In DDAVP-treated patients the relative risk of requiring re-operation due to bleeding was 0.56 (95%CI: 0.18 to 1.73). There was no statistically significant effect overall for mortality and non-fatal myocardial infarction in DDAVP-treated patients compared with control (RR=1.53: 95%CI: 0.58 to 4.05) and (RR=1.52: 95%CI: 0.67 to 3.49) respectively.

REVIEWER'S CONCLUSIONS

There is no convincing evidence that desmopressin minimises perioperative allogeneic RBC transfusion in patients who do not have congenital bleeding disorders. These data suggest that there is no benefit of using DDAVP as a means of minimising perioperative allogeneic RBC transfusion. This meta-analysis had 90% power to detect a relative risk reduction of at least 17% for receiving a red cell transfusion at alpha = 0.05 (two-sided).

Development of a decision aid for atrial fibrillation who are considering antithrombotic therapy

With patients demanding a greater role in the clinical decision-making process, many researchers are developing and disseminating decision aids for various medical conditions. In this article, we outline the essential elements in the development and evaluation of a decision aid to help patients with atrial fibrillation choose, in consultation with their physicians, appropriate antithrombotic therapy (warfarin, aspirin, or no therapy) to prevent stroke. We also outline possible future directions regarding the implementation and evaluation of this decision aid. This information should enable clinicians to better understand the role that decision aids may have in their interactions with patients.

Patient preference-based treatment thresholds and recommendations: a comparison of decision-analytic modeling with the probability-tradeoff technique

BACKGROUND

Decision analysis (DA) and the probability-tradeoff technique (PTOT) are patient preference-based methods of determining optimal therapy for individuals. Using aspirin therapy for the primary prevention of stroke and myocardial infarction (MI) in elderly persons as an example, the objective of this study was to determine whether group-level treatment thresholds and individual-level treatment recommendations derived using PTOT are identical to those of DA incorporating the patients' own values.

METHODS

Persons in a pilot study of the efficacy of aspirin in the prevention of stroke and MI were asked to participate. Participant values and utilities for pertinent health states (e.g., minor and major stroke, MI, major bleeding episode) were determined. Then, in three hypothetical clinical situations in which the chance of stroke or MI was varied, PTOT was used to directly determine treatment thresholds for aspirin therapy (i.e., the smallest reduction in MI or stroke risk for which participants would be willing to take aspirin). Using DA modeling, with the same probabilities of events as in the PTOT exercise and incorporating participants' own values, treatment thresholds for the three clinical situations were determined. The thresholds determined by the two approaches were compared. Finally, based on these treatment thresholds, using the best estimates of the efficacy of aspirin to prevent first-time stroke and MI, PTOT and DA treatment recommendations for individual participants were compared.

RESULTS

The 42 participants reported that a major stroke was the least desirable health state, followed by MI, minor stroke, and major bleeding. The minimum risk reduction required to take aspirin was greater for MI prevention compared with stroke prevention. For the two clinical situations in which the hypothetical efficacy of aspirin to prevent stroke was varied, treatment thresholds for the PTOT versus DA approaches differed (p < 0.04), but this difference was not significant (p = 0.19) for the MI-based clinical situation. Using the best estimate of the efficacy of aspirin to prevent first-time stroke and MI, PTOT and DA treatment recommendations whether or not to take aspirin were discordant for 38% of participants (16 of 42) (p < 0.001).

CONCLUSIONS

Patient preference-based group-level treatment thresholds and individual-level treatment recommendations can differ significantly depending on whether PTOT or DA is used, apparently because the two emphasize different aspects of the decision-making process. DA theory assumes that effective therapeutic decision making should maximize both quality and quantity of life; with PTOT, the emphasis for effective clinical decision making allows patients to be fully engaged in the process, thus hopefully leading to fully informed decisions that may result in satisfaction and compliance.

Decision aids for patients considering options affecting cancer outcomes: evidence of efficacy and policy implications

Some cancer screening and treatment decisions are not clear cut because outcomes are uncertain or options have different benefit/risk profiles. "Decision aids" have been developed as adjuncts to counseling so that patients can learn about benefits and risks, can consider their personal values, and can participate with their practitioner in decision making. The purpose of this paper is to review published evidence about the efficacy of decision aids focused on cancer outcomes and to outline research and dissemination issues. Studies evaluating cancer-related decision aids demonstrate that they are acceptable to patients and help those who are uncertain at baseline to make choices. They also increase the likelihood that choices are based on better knowledge, realistic expectations of outcomes, and personal values. Decision aids reduce some dimensions of decisional conflict, and their effect on decisions is variable. Few studies examine the downstream effects of decision aids on long-term persistence with choices, regret, and quality of life. The differences between simpler and more intensive methods of decision support appear to be negligible in terms of knowledge and satisfaction as well as variable in terms of decisions and decisional conflict. However, more intensive methods are superior in terms of user acceptability and of the extent to which choices are based on realistic expectations and personal values. The clinical importance of these differences and the cost-effectiveness remain to be established. On the basis of this review, several recommendations for research are made, and dissemination issues are identified.

When should hypertension be treated? The different perspectives of Canadian family physicians and patients

BACKGROUND

Hypertension guidelines from different organizations often specify different treatment thresholds, and none explicitly state how these thresholds were chosen. This study was undertaken to determine the treatment thresholds of family physicians and hypertensive patients for mild, uncomplicated essential hypertension. A subject's treatment threshold can be determined by eliciting the minimum reduction in cardiovascular risk that he or she feels outweighs the inconvenience, costs and side effects of antihypertensive therapy (the minimal clinically important difference [MCID]).

METHODS

The study subjects consisted of a random sample of family physicians and a consecutive sample of hypertensive patients without overt cardiovascular disease from Ottawa and Edmonton. To determine participants' MCIDs, we used a survey employing hypothetical scenarios (each depicting a different baseline cardiovascular risk) and a probability trade-off tool.

RESULTS

Of 94 family physicians and 146 patients approached for the study, 72 and 74 participated respectively. There was marked variability in the MCIDs of both groups. In general, patients were less likely to want antihypertensive therapy than physicians, particularly when baseline cardiovascular risks were low: 49% v. 64% (p = 0.06), 68% v. 92% (p < 0.001) and 86% v. 100% (p = 0.001) for 5-year cardiovascular risks of 2%, 5% and 10% respectively. Moreover, patients expressed larger MCIDs (i.e., wanted greater benefits before accepting therapy) than physicians. However, a subgroup of patients (15% to 26%, depending on the scenario) wanted treatment even if there was no anticipated benefit. Multivariate analysis showed that no sociodemographic factors strongly predicted the MCIDs of either group.

INTERPRETATION

Guidelines that set treatment thresholds on the basis of physician or expert opinion may not accurately reflect the preferences of hypertensive patients. There is a need for patient decision aids and attention to patient preferences when initiation of antihypertensive therapy is considered for the prevention of cardiovascular disease. Further research is needed to define treatment thresholds for other chronic conditions and in other groups.

Cost effectiveness of epoetin-alpha to augment preoperative autologous blood donation in elective cardiac surgery

OBJECTIVE

The objective of this study was to assess the cost effectiveness of using epoetin-alpha (erythropoietin) to augment preoperative autologous donation (PAD) of blood prior to elective cardiac surgery.

DESIGN AND SETTING

We designed a decision-analytic model incorporating the risk of receiving allogeneic blood, the costs of blood products, the likelihood of developing transfusion-related diseases, the costs of transfusion-related diseases and their impact on life expectancy, and the effect of epoetin-alpha on the probability of transfusion.

INTERVENTIONS

The efficacy of epoetin-alpha was derived from data from a meta-analysis of published randomised trials comparing the use of epoetin-alpha to augment PAD with the use of PAD alone. Estimates for the other parameters were obtained by a systematic review of the literature.

MAIN OUTCOME MEASURES AND RESULTS

The use of epoetin-alpha reduced the proportion of patients receiving allogeneic transfusions by 60% (from 31.6 to 12.7%). However, this led to only a modest benefit of 0.000035 life years gained per patient and an incremental cost per life year gained of $Can44.6 million (1998 Canadian dollars). A detailed sensitivity analysis confirmed that the cost-effectiveness ratio was larger than that which is generally considered acceptable.

CONCLUSIONS

Our study indicates that the use of epoetin-alpha to reduce perioperative allogeneic transfusions in cardiac surgery is not cost effective.

The use of technologies to minimize exposure to perioperative allogeneic blood transfusion in elective surgery. A survey of Canadian hospitals

BACKGROUND

Despite the growing medical and public interest in reducing exposure to allogeneic blood, little is known about the use of alternatives to allogeneic transfusion. This study was conducted to determine the availability of these technologies in Canadian hospitals and was undertaken under the auspices of the International Study of Peri-Operative Transfusion (ISPOT), a 10-country study of the effectiveness of, attitudes toward, and practices related to the use of alternatives to allogeneic transfusion.

METHODS

A cross-sectional national mail survey of Canadian hospitals with greater than 50 medical/surgical beds. Chiefs of anesthesia, surgery, and the divisions of cardiac, orthopedic, vascular, and urology were initially mailed a brief postcard asking which of seven technologies were used in their center. This was then followed up with a one-page questionnaire asking how frequently the technologies were used, their thoughts on the appropriateness of the use of the technologies, barriers to their greater use, and reasons for nonuse of the technologies.

RESULTS

Response rates to the postcard survey ranged from 70%-98%, depending on the technology and type of surgery, and ranged from 27%-53% for the follow-up questionnaire. All technologies were used most frequently in cardiac surgery. Aprotinin, tranexamic acid, aminocaproic acid, desmopressin, and cell salvage were reported used in over 70% of cardiac surgery centers. Of these, tranexamic acid and cell salvage were the only ones used routinely in some centers. Acute normovolemic hemodilution and erythropoietin were used in 45% and 20% of cardiac centers, respectively. The drugs were used in less than 15% of orthopedic, vascular, and urologic divisions, with the exception of desmopressin in urologic and vascular surgery and aminocaproic acid in urologic surgery. The techniques of cell salvage and acute normovolemic hemodilution were used in 30%-45% of these divisions, with the exception of cell salvage, which was used in less than 15% of urology units. In more than 60% of cases, the technologies were considered to be used "about right," although an important minority felt that they were underused.

CONCLUSIONS

In general, alternatives to perioperative allogeneic transfusion were rarely used except in cardiac surgery.

Technologies to minimize blood transfusion in cardiac and orthopedic surgery. Results of a practice variation survey in nine countries. International Study of Peri-operative Transfusion (ISPOT) Investigators

OBJECTIVES

Due to the discovery in the 1980s that blood transfusion can transmit HIV, there has been increased interest in technologies that reduce the amount of allogeneic blood used during and after surgery. These technologies include drugs (aprotinin, tranexamic acid, epsilon-aminocaproic acid, erythropoietin), devices (cell salvage), and techniques (acute hemodilution, predeposited autologous donation). The purpose of this study was to ascertain the degree of practice variation, if any, that exists for eight technologies in nine countries in orthopedic and cardiac surgery.

METHODS

In each country, either all hospitals or a random sample of hospitals with medical/surgical beds were surveyed between 1995 and 1997. Two instruments were used. The first instrument was a postcard that asked recipients whether the technologies were currently being used in their hospital for orthopedic and/or cardiac surgery to reduce perioperative allogeneic transfusion. The second questionnaire elicited information regarding the degree of use both in qualitative and quantitative terms. Data were collected, entered, and analyzed in each country, with summary results submitted to the Canadian coordinating center on a standardized data collection form.

RESULTS

Pharmaceuticals were generally used in a much smaller proportion of hospitals in orthopedic than in cardiac surgery. Aprotinin and tranexamic acid were the drugs most frequently used in cardiac surgery. Nonpharmacological technologies were used to a greater degree than drugs in orthopedic surgery, although there was wide variation among technologies and countries. Acute hemodilution and cell salvage were used in a greater proportion of hospitals for cardiac surgery than orthopedic surgery.

CONCLUSIONS

The results of this survey indicate that there is considerable practice variation in the use of technologies to minimize exposure to perioperative allogeneic transfusion within and between countries.