Is there sufficient evidence for tuning fork tests in diagnosing fractures? A systematic review

OBJECTIVE

To determine the diagnostic accuracy of tuning fork tests for detecting fractures.

DESIGN

Systematic review of primary studies evaluating the diagnostic accuracy of tuning fork tests for the presence of fracture.

DATA SOURCE

We searched MEDLINE, CINAHL, AMED, EMBASE, Sports Discus, CAB Abstracts and Web of Science from commencement to November 2012. We manually searched the reference lists of any review papers and any identified relevant studies.

STUDY SELECTION AND DATA EXTRACTION

Two reviewers independently reviewed the list of potentially eligible studies and rated the studies for quality using the QUADAS-2 tool. Data were extracted to form 2×2 contingency tables. The primary outcome measure was the accuracy of the test as measured by its sensitivity and specificity with 95% CIs.

DATA SYNTHESIS

We included six studies (329 patients), with two types of tuning fork tests (pain induction and loss of sound transmission). The studies included patients with an age range 7-60 years. The prevalence of fracture ranged from 10% to 80%. The sensitivity of the tuning fork tests was high, ranging from 75% to 100%. The specificity of the tests was highly heterogeneous, ranging from 18% to 95%.

CONCLUSIONS

Based on the studies in this review, tuning fork tests have some value in ruling out fractures, but are not sufficiently reliable or accurate for widespread clinical use. The small sample size of the studies and the observed heterogeneity make generalisable conclusion difficult.

Communicating cardiovascular disease risk: an interview study of General Practitioners' use of absolute risk within tailored communication strategies

BACKGROUND

Cardiovascular disease (CVD) prevention guidelines encourage assessment of absolute CVD risk - the probability of a CVD event within a fixed time period, based on the most predictive risk factors. However, few General Practitioners (GPs) use absolute CVD risk consistently, and communication difficulties have been identified as a barrier to changing practice. This study aimed to explore GPs' descriptions of their CVD risk communication strategies, including the role of absolute risk.

METHODS

Semi-structured interviews were conducted with a purposive sample of 25 GPs in New South Wales, Australia. Transcribed audio-recordings were thematically coded, using the Framework Analysis method to ensure rigour.

RESULTS

GPs used absolute CVD risk within three different communication strategies: 'positive', 'scare tactic', and 'indirect'. A 'positive' strategy, which aimed to reassure and motivate, was used for patients with low risk, determination to change lifestyle, and some concern about CVD risk. Absolute risk was used to show how they could reduce risk. A 'scare tactic' strategy was used for patients with high risk, lack of motivation, and a dismissive attitude. Absolute risk was used to 'scare' them into taking action. An 'indirect' strategy, where CVD risk was not the main focus, was used for patients with low risk but some lifestyle risk factors, high anxiety, high resistance to change, or difficulty understanding probabilities. Non-quantitative absolute risk formats were found to be helpful in these situations.

CONCLUSIONS

This study demonstrated how GPs use three different communication strategies to address the issue of CVD risk, depending on their perception of patient risk, motivation and anxiety. Absolute risk played a different role within each strategy. Providing GPs with alternative ways of explaining absolute risk, in order to achieve different communication aims, may improve their use of absolute CVD risk assessment in practice.

General practitioners' use of absolute risk versus individual risk factors in cardiovascular disease prevention: an experimental study

OBJECTIVE

To understand general practitioners' (GPs) use of individual risk factors (blood pressure and cholesterol levels) versus absolute risk in cardiovascular disease (CVD) risk management decision-making.

DESIGN

Randomised experiment. Absolute risk, systolic blood pressure (SBP), cholesterol ratio (total cholesterol/high-density lipoprotein (TC/HDL)) and age were systematically varied in hypothetical cases. High absolute risk was defined as 5-year risk of a cardiovascular event >15%, high blood pressure levels varied between SBP 147 and 179 mm Hg and high cholesterol (TC/HDL ratio) between 6.5 and 7.2 mmol/L.

SETTING

4 GP conferences in Australia.

PARTICIPANTS

144 Australian GPs.

OUTCOMES

GPs indicated whether they would prescribe cholesterol and/or blood pressure lowering medication. Analyses involved logistic regression.

RESULTS

For patients with high blood pressure: 93% (95% CI 86% to 96%) of high absolute risk patients and 83% (95% CI 76% to 88%) of lower absolute risk patients were prescribed blood pressure medication. Conversely, 30% (95% CI 25% to 36%) of lower blood pressure patients were prescribed blood pressure medication if absolute risk was high and 4% (95% CI 3% to 5%) if lower. 69% of high cholesterol/high absolute risk patients were prescribed cholesterol medication (95% CI 61% to 77%) versus 34% of high cholesterol/lower absolute risk patients (95% CI 28% to 41%). 36% of patients with lower cholesterol (95% CI 30% to 43%) were prescribed cholesterol medication if absolute risk was high versus 10% if lower (95% CI 8% to 13%).

CONCLUSIONS

GPs' decision-making was more consistent with the management of individual risk factors than an absolute risk approach, especially when prescribing blood pressure medication. The results suggest medical treatment of lower risk patients (5-year risk of CVD event <15%) with mildly elevated blood pressure or cholesterol levels is likely to occur even when an absolute risk assessment is specifically provided. The results indicate a need for improving uptake of absolute risk guidelines and GP understanding of the rationale for using absolute risk.

I don't believe it, but i'd better do something about it: patient experiences of online heart age risk calculators

Background

Health risk calculators are widely available on the Internet, including cardiovascular disease (CVD) risk calculators that estimate the probability of a heart attack, stroke, or death over a 5- or 10-year period. Some calculators convert this probability to “heart age”, where a heart age older than current age indicates modifiable risk factors. These calculators may impact patient decision making about CVD risk management with or without clinician involvement, but little is known about how patients use them. Previous studies have not investigated patient understanding of heart age compared to 5-year percentage risk, or the best way to present heart age.

Objective

This study aimed to investigate patient experiences and understanding of online heart age calculators that use different verbal, numerical, and graphical formats, based on 5- and 10-year Framingham risk equations used in clinical practice guidelines around the world.

Methods

General practitioners in New South Wales, Australia, recruited 26 patients with CVD/lifestyle risk factors who were not taking cholesterol or blood pressure-lowering medication in 2012. Participants were asked to “think aloud” while using two heart age calculators in random order, with semi-structured interviews before and after. Transcribed audio recordings were coded and a framework analysis method was used.

Results

Risk factor questions were often misinterpreted, reducing the accuracy of the calculators. Participants perceived older heart age as confronting and younger heart age as positive but unrealistic. Unexpected or contradictory results (eg, low percentage risk but older heart age) led participants to question the credibility of the calculators. Reasons to discredit the results included the absence of relevant lifestyle questions and impact of corporate sponsorship. However, the calculators prompted participants to consider lifestyle changes irrespective of whether they received younger, same, or older heart age results.

Conclusions

Online heart age calculators can be misunderstood and disregarded if they produce unexpected or contradictory results, but they may still motivate lifestyle changes. Future research should investigate both the benefits and harms of communicating risk in this way, and how to increase the reliability and credibility of online health risk calculators.

A Community Jury on PSA screening: what do well-informed men want the government to do about prostate cancer screening--a qualitative analysis

OBJECTIVE

Cancer screening policies and programmes should take account of public values and concerns. This study sought to determine the priorities, values and concerns of men who were 'fully informed' about the benefits and harms of prostate-specific antigen (PSA) screening; and empirically examine the value of a community jury in eliciting public values on PSA screening.

SETTING

Community jury was convened on the Gold Coast, Queensland (Australia) to consider PSA screening benefits and harms, and whether government campaigns on PSA screening should be conducted.

PARTICIPANTS

27 men (volunteers) aged 50-70 with no personal history of prostate cancer and willing to attend jury 6-7 April 2013: 12 were randomly allocated to jury (11 attended).

OUTCOME MEASURES

A qualitative analysis was conducted of the jury deliberations (audio-recorded and transcribed) to elicit the jury's views and recommendations. A survey determined the impact of the jury process on participants' individual testing decisions compared with control group.

RESULTS

The jury concluded governments should not invest in programmes focused on PSA screening directed at the public because the PSA test did not offer sufficient reassurance or benefit and could raise unnecessary alarm. It recommended an alternative programme to support general practitioners to provide patients with better quality and more consistent information about PSA screening. After the jury, participants were less likely to be tested in the future compared with the controls, but around half said they would still consider doing so.

CONCLUSIONS

The jury's unanimous verdict about government programmes was notable in the light of their divergent views on whether or not they would be screened themselves in the future. Community juries provide valuable insights into the priorities and concerns of men weighing up the benefits and harms of PSA screening. It will be important to assess the degree to which the findings are generalisable to other settings.

A is for aphorism. 'A normal person is only someone who hasn't been investigated enough yet'

Every year I read many applications for research grants, mostly for the National Health and Medical Research Council (NHMRC). Most start in roughly the same way: an estimate of the number of people suffering from the disease in question and the cost of the disease to the economy. From reading these applications, one would think the health of Australians is in crisis and the economic effects of ill health devastating. The evidence, however, is quite the reverse. Australians currently enjoy one of the longest life expectancies in human history. Adult male mortality rates have fallen from 207 per 1000 male adults in 1970 to 81 in 2009; female mortality rates have fallen from 117 to 47 in the same period. These trends continue to improve. There has been a spectacular decline in the prevalence of cardiovascular disease in Australia from the levels seen in the 1960s and 1970s. In the 2011-2013 Australian health survey, over half of the population rated their health as very good or excellent; there had been no change from 5 years previously, despite the ageing of the population. Even in the age group of 85 years and over, 60% rate their health as good to excellent.

General practitioners' use of different cardiovascular risk assessment strategies: a qualitative study

OBJECTIVES

To identify factors that influence the extent to which general practitioners use absolute risk (AR) assessment in cardiovascular disease (CVD) risk assessment.

DESIGN, SETTING AND PARTICIPANTS

Semi-structured interviews with 25 currently practising GPs from eight Divisions of General Practice in New South Wales, Australia, between October 2011 and May 2012. Data were analysed using framework analysis.

RESULTS

The study identified five strategies that GPs use with patients in different situations, defined in terms of the extent to which AR was used and the reasons given for this: the AR-focused strategy, used when AR assessment was considered useful for the patient; the AR-adjusted strategy, used to account for additional risk factors such as family history; the clinical judgement strategy, used when GPs considered that their judgement took multiple risk factors into account as effectively as AR; the passive disregard strategy, used when GPs lacked sufficient time, access or experience to use AR; and the active disregard strategy, used when AR was considered to be inappropriate for the patient. The strategies were linked with different opportunity, capability and motivation barriers to the use of AR.

CONCLUSIONS

This study provides an in-depth insight into the factors that influence GPs' use of AR in CVD risk assessment. The results suggest that GPs use a range of strategies in different situations, so different approaches may be required to improve the use of AR guidelines in practice.

Is the problem that everything is a diagnosis?

BACKGROUND

Overdiagnosis is the diagnosis of 'illnesses' that would never have caused patients harm but potentially exposes them to treat-ments where the risks outweigh the benefits. The problem of overdiagnosis is affecting an increasing proportion of the population.

OBJECTIVE

Overdiagnosis is occurring in several different ways: by changes in the definition or threshold of disease, labelling of risk factors as diseases, early detection from both deliberate screening programs and incidental detection ('incidentalomas'), and the medicalisation of life, particularly in psychiatry.

DISCUSSION

General practitioners often carry the burden of care for patients who have been overdiagnosed. It is important that general practi-tioners are aware of the potential harm of overdiagnosis, particularly through early detection and aggressive management of early disease.

Monitoring in clinical biochemistry

Monitoring tests form an increasing proportion of the workload in clinical biochemistry and biochemists can help by providing clinicians with information about the variability and precision of tests, the time frame for pharmacodynamic stabilisation after a treatment change, and the frequency of testing. This paper outlines the phases of monitoring, and how to decide if monitoring is beneficial, which test to use for monitoring, when a change in the test result indicates a need for the change in treatment and the length of testing intervals. We conclude with some recommendations for biochemists for future areas of research and advice that can be given to clinicians.

A is for aphorism - a woman is pregnant until proven otherwise

I arrived late at my shift in the emergency department, direct from a session in general practice. The nursing staff had an 'easy' patient for me: a woman, 19 years of age, with pelvic pain and dysuria, whose urinanalysis showed white cells and nitrites.

Prioritising CVD prevention therapy - absolute risk versus individual risk factors

BACKGROUND

Previous studies suggest that a high proportion of persons at high risk of cardiovascular disease in Australia are not receiving adequate disease prevention with blood pressure and lipid lowering therapy. However, it is not clear how a move to an absolute risk factor approach will affect the proportion of the population that is treated with blood pressure and lipid lowering therapy versus treatment based on individual risk factors.

METHODS

We classified participants in the AusDiab follow up cohort study who had no previous history of cardiovascular disease and who were not taking blood pressure or lipid lowering medication currently according to the presence of individual risk factors versus combined absolute risk.

RESULTS

Of the 3627 participants who were untreated, 429 (12%) had elevated blood pressure and 983 (27%) had dyslipidaemia, with 167 (5%) having both risk factors. 1245 participants (34%) would be treated using the individual risk factor approaches and 281 (8%) using the absolute risk approach based on the most clearly defined criteria of high risk.

CONCLUSION

Moving to an absolute risk approach prioritises treatment to those most at risk, but ambiguities regarding what is meant by the absolute risk approach remain.

Aloe vera for treating acute and chronic wounds

BACKGROUND

Aloe vera is a cactus-like perennial succulent belonging to the Liliaceae Family that is commonly grown in tropical climates. Animal studies have suggested that Aloe vera may help accelerate the wound healing process.

OBJECTIVES

To determine the effects of Aloe vera-derived products (for example dressings and topical gels) on the healing of acute wounds (for example lacerations, surgical incisions and burns) and chronic wounds (for example infected wounds, arterial and venous ulcers).

SEARCH METHODS

We searched the Cochrane Wounds Group Specialised Register (9 September 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 3), Ovid MEDLINE (2005 to August Week 5 2011), Ovid MEDLINE (In-Process & Other Non-Indexed Citations 8 September 2011), Ovid EMBASE (2007 to 2010 Week 35), Ovid AMED (1985 to September 2011) and EBSCO CINAHL (1982 to 9 September 2011). We did not apply date or language restrictions.

SELECTION CRITERIA

We included all randomised controlled trials that evaluated the effectiveness of Aloe vera, aloe-derived products and a combination of Aloe vera and other dressings as a treatment for acute or chronic wounds. There was no restriction in terms of source, date of publication or language. An objective measure of wound healing (either proportion of completely healed wounds or time to complete healing) was the primary endpoint.

DATA COLLECTION AND ANALYSIS

Two review authors independently carried out trial selection, data extraction and risk of bias assessment, checked by a third review author.

MAIN RESULTS

Seven trials were eligible for inclusion, comprising a total of 347 participants. Five trials in people with acute wounds evaluated the effects of Aloe vera on burns, haemorrhoidectomy patients and skin biopsies. Aloe vera mucilage did not increase burn healing compared with silver sulfadiazine (risk ratio (RR) 1.41, 95% confidence interval (CI) 0.70 to 2.85). A reduction in healing time with Aloe vera was noted after haemorrhoidectomy (RR 16.33 days, 95% CI 3.46 to 77.15) and there was no difference in the proportion of patients completely healed at follow up after skin biopsies. In people with chronic wounds, one trial found no statistically significant difference in pressure ulcer healing with Aloe vera (RR 0.10, 95% CI -1.59 to 1.79) and in a trial of surgical wounds healing by secondary intention Aloe vera significantly delayed healing (mean difference 30 days, 95% CI 7.59 to 52.41). Clinical heterogeneity precluded meta-analysis. The poor quality of the included trials indicates that the trial results must be viewed with extreme caution as they have a high risk of bias.

AUTHORS' CONCLUSIONS

There is currently an absence of high quality clinical trial evidence to support the use of Aloe vera topical agents or Aloe vera dressings as treatments for acute and chronic wounds.

Cardiovascular risk scores do not account for the effect of treatment: a review

Objective

To compare the strengths and limitations of cardiovascular risk scores available for clinicians in assessing the global (absolute) risk of cardiovascular disease.

Design

Review of cardiovascular risk scores.

Data sources

Medline (1966 to May 2009) using a mixture of MeSH terms and free text for the keywords ‘cardiovascular’, ‘risk prediction’ and ‘cohort studies’.

Eligibility criteria for selecting studies

A study was eligible if it fulfilled the following criteria: (1) it was a cohort study of adults in the general population with no prior history of cardiovascular disease and not restricted by a disease condition; (2) the primary objective was the development of a cardiovascular risk score/equation that predicted an individual's absolute cardiovascular risk in 5–10 years; (3) the score could be used by a clinician to calculate the risk for an individual patient.

Results

21 risk scores from 18 papers were identified from 3536 papers. Cohort size ranged from 4372 participants (SHS) to 1591209 records (QRISK2). More than half of the cardiovascular risk scores (11) were from studies with recruitment starting after 1980. Definitions and methods for measuring risk predictors and outcomes varied widely between scores. Fourteen cardiovascular risk scores reported data on prior treatment, but this was mainly limited to antihypertensive treatment. Only two studies reported prior use of lipid-lowering agents. None reported on prior use of platelet inhibitors or data on treatment drop-ins.

Conclusions

The use of risk-factor-modifying drugs—for example, statins—and disease-modifying medication—for example, platelet inhibitors—was not accounted for. In addition, none of the risk scores addressed the effect of treatment drop-ins—that is, treatment started during the study period. Ideally, a risk score should be derived from a population free from treatment. The lack of accounting for treatment effect and the wide variation in study characteristics, predictors and outcomes causes difficulties in the use of cardiovascular risk scores for clinical treatment decision.

Antibiotics for bronchiolitis in children

BACKGROUND

Bronchiolitis is a serious, potentially life-threatening respiratory illness commonly affecting babies. It is often caused by respiratory syncytial virus (RSV). Antibiotics are not recommended for bronchiolitis unless there is concern about complications such as secondary bacterial pneumonia or respiratory failure. Nevertheless, they are used at rates of 34% to 99% in uncomplicated cases.

OBJECTIVES

To evaluate the effectiveness of antibiotics for bronchiolitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2010, issue 4), which includes the Cochrane Acute Respiratory Infection Group's Specialised Register, and the Database of Abstracts of Reviews of Effects, MEDLINE (January 1966 to November 2010), EMBASE (1990 to December 2010) and Current Contents (2001 to December 2010).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing antibiotics to placebo in children under two years diagnosed with bronchiolitis, using clinical criteria (including respiratory distress preceded by coryzal symptoms with or without fever). Primary clinical outcomes included time to resolution of signs or symptoms (pulmonary markers included respiratory distress, wheeze, crepitations, oxygen saturation and fever). Secondary outcomes included hospital admissions, length of hospital stay, re-admissions, complications or adverse events and radiological findings.

DATA COLLECTION AND ANALYSIS

Two review authors independently analysed the search results.

MAIN RESULTS

Five studies (543 participants) met our inclusion criteria. One study randomised 52 children to either ampicillin or placebo and found no significant difference between the two groups for length of illness. A small study (21 children) with higher risk of potential bias randomised children with proven RSV infection to clarithromycin or placebo and found clarithromycin may reduce hospital re-admission (8% antibiotics versus 44% placebo; Fishers exact; P = 0.081). The two studies (267 children) providing adequate data for length of hospital stay showed no difference between antibiotics and control (pooled mean difference 0.34; 95% CI -0.71 to 1.38). Two studies randomised children to intravenous ampicillin, oral erythromycin and control and found no difference for most symptom measures. None of the trials reported deaths.

AUTHORS' CONCLUSIONS

This review found minimal evidence to support the use of antibiotics for bronchiolitis. Research to identify a possible small subgroup of patients who have complications from bronchiolitis such as respiratory failure and who may benefit from antibiotics is justified.

Predicting influenza A and 2009 H1N1 influenza in patients admitted to hospital with acute respiratory illness

OBJECTIVE

To create a clinical decision tool for suspected influenza A (including 2009 H1N1) to facilitate treatment and isolation decisions for patients admitted to hospital with an acute respiratory illness from the emergency department (ED) during a 2009 H1N1 pandemic.

METHODS

Cross-sectional study conducted in two hospitals in Queensland, Australia. All patients admitted to hospital from the ED between 24 May and 16 August 2009 with an acute respiratory illness were included. All had nasal and throat swabs taken. Data were collected from clinical chart review regarding clinical symptoms, co-morbidities, examination findings, pathology and radiology results. Influenza A status was detected by reverse transcription-PCR assay. Univariate and multivariate regression analyses were performed to identify independent predictors of influenza A status.

RESULTS

346 consecutive patients were identified, of which 106 were positive for 2009 H1N1 influenza; an additional 11 patients were positive for other influenza A viruses. Independent clinical predictors (with points allocated using weighted scoring) for all types of influenza A in patients admitted with acute respiratory illness were: age 18-64 years (2 points); history of fever (2); cough (1); normal level of consciousness (2); C-reactive protein >5 and ≤ 100 mg/l (2) and normal leucocyte count (1). A clinical score of 5 (presence of two or three predictors) gave a sensitivity of 93% (95% CI 87% to 96%), specificity of 36% (95% CI 30% to 42%), resulting in a negative-predictive value of 91% (95% CI 83% to 95%).

CONCLUSION

A clinical prediction tool was developed that may be able to assist in making appropriate isolation decisions during future 2009 H1N1 outbreaks.

Information from pharmaceutical companies and the quality, quantity, and cost of physicians' prescribing: a systematic review

BACKGROUND

Pharmaceutical companies spent $57.5 billion on pharmaceutical promotion in the United States in 2004. The industry claims that promotion provides scientific and educational information to physicians. While some evidence indicates that promotion may adversely influence prescribing, physicians hold a wide range of views about pharmaceutical promotion. The objective of this review is to examine the relationship between exposure to information from pharmaceutical companies and the quality, quantity, and cost of physicians' prescribing.

METHODS AND FINDINGS

We searched for studies of physicians with prescribing rights who were exposed to information from pharmaceutical companies (promotional or otherwise). Exposures included pharmaceutical sales representative visits, journal advertisements, attendance at pharmaceutical sponsored meetings, mailed information, prescribing software, and participation in sponsored clinical trials. The outcomes measured were quality, quantity, and cost of physicians' prescribing. We searched Medline (1966 to February 2008), International Pharmaceutical Abstracts (1970 to February 2008), Embase (1997 to February 2008), Current Contents (2001 to 2008), and Central (The Cochrane Library Issue 3, 2007) using the search terms developed with an expert librarian. Additionally, we reviewed reference lists and contacted experts and pharmaceutical companies for information. Randomized and observational studies evaluating information from pharmaceutical companies and measures of physicians' prescribing were independently appraised for methodological quality by two authors. Studies were excluded where insufficient study information precluded appraisal. The full text of 255 articles was retrieved from electronic databases (7,185 studies) and other sources (138 studies). Articles were then excluded because they did not fulfil inclusion criteria (179) or quality appraisal criteria (18), leaving 58 included studies with 87 distinct analyses. Data were extracted independently by two authors and a narrative synthesis performed following the MOOSE guidelines. Of the set of studies examining prescribing quality outcomes, five found associations between exposure to pharmaceutical company information and lower quality prescribing, four did not detect an association, and one found associations with lower and higher quality prescribing. 38 included studies found associations between exposure and higher frequency of prescribing and 13 did not detect an association. Five included studies found evidence for association with higher costs, four found no association, and one found an association with lower costs. The narrative synthesis finding of variable results was supported by a meta-analysis of studies of prescribing frequency that found significant heterogeneity. The observational nature of most included studies is the main limitation of this review.

CONCLUSIONS

With rare exceptions, studies of exposure to information provided directly by pharmaceutical companies have found associations with higher prescribing frequency, higher costs, or lower prescribing quality or have not found significant associations. We did not find evidence of net improvements in prescribing, but the available literature does not exclude the possibility that prescribing may sometimes be improved. Still, we recommend that practitioners follow the precautionary principle and thus avoid exposure to information from pharmaceutical companies. Please see later in the article for the Editors' Summary.

Qualification versus validation of biomarkers

The phases of research used to evaluate new drugs provide a useful reference point for determining the studies that need to be conducted to evaluate new biomarkers. However, biomarkers do not have a single pathway for changing health outcomes and may be used for a variety of purposes, such as improving diagnostic criteria, improving prognosis, improving the monitoring of disease or as a measurement of health outcomes. The impact on health outcomes is also less direct and is dependent on the sequence of actions taken as a consequence of the test results. The different purposes of biomarkers and the less direct effect on health outcomes require different study designs to those used for the evaluation of pharmaceutical products and a more careful interpretation of results. Greater collaboration between researchers designing laboratory-based qualification studies and researchers designing clinical validation studies could achieve a process of evaluation for biomarkers that is both reliable and efficient.

Systematic review and individual patient data meta-analysis of diagnosis of heart failure, with modelling of implications of different diagnostic strategies in primary care

OBJECTIVES

To assess the accuracy in diagnosing heart failure of clinical features and potential primary care investigations, and to perform a decision analysis to test the impact of plausible diagnostic strategies on costs and diagnostic yield in the UK health-care setting.

DATA SOURCES

MEDLINE and CINAHL were searched from inception to 7 July 2006. 'Grey literature' databases and conference proceedings were searched and authors of relevant studies contacted for data that could not be extracted from the published papers.

REVIEW METHODS

A systematic review of the clinical evidence was carried out according to standard methods. Individual patient data (IPD) analysis was performed on nine studies, and a logistic regression model to predict heart failure was developed on one of the data sets and validated on the other data sets. Cost-effectiveness modelling was based on a decision tree that compared different plausible investigation strategies.

RESULTS

Dyspnoea was the only symptom or sign with high sensitivity (89%), but it had poor specificity (51%). Clinical features with relatively high specificity included history of myocardial infarction (89%), orthopnoea (89%), oedema (72%), elevated jugular venous pressure (70%), cardiomegaly (85%), added heart sounds (99%), lung crepitations (81%) and hepatomegaly (97%). However, the sensitivity of these features was low, ranging from 11% (added heart sounds) to 53% (oedema). Electrocardiography (ECG), B-type natriuretic peptides (BNP) and N-terminal pro-B-type natriuretic peptides (NT-proBNP) all had high sensitivities (89%, 93% and 93% respectively). Chest X-ray was moderately specific (76-83%) but insensitive (67-68%). BNP was more accurate than ECG, with a relative diagnostic odds ratio of ECG/BNP of 0.32 (95% CI 0.12-0.87). There was no difference between the diagnostic accuracy of BNP and NT-proBNP. A model based upon simple clinical features and BNP derived from one data set was found to have good validity when applied to other data sets. A model substituting ECG for BNP was less predictive. From this a simple clinical rule was developed: in a patient presenting with symptoms such as breathlessness in whom heart failure is suspected, refer directly to echocardiography if the patient has a history of myocardial infarction or basal crepitations or is a male with ankle oedema; otherwise, carry out a BNP test and refer for echocardiography depending on the results of the test. On the basis of the cost-effectiveness analysis carried out, such a decision rule is likely to be considered cost-effective to the NHS in terms of cost per additional case detected. The cost-effectiveness analysis further suggested that, if likely benefit to the patient in terms of improved life expectancy is taken into account, the optimum strategy would be to refer all patients with symptoms suggestive of heart failure directly for echocardiography.

CONCLUSIONS

The analysis suggests the need for important changes to the NICE recommendations. First, BNP (or NT-proBNP) should be recommended over ECG and, second, some patients should be referred straight for echocardiography without undergoing any preliminary investigation. Future work should include evaluation of the clinical rule described above in clinical practice.

Systematic review of the diagnostic accuracy of C-reactive protein to detect bacterial infection in nonhospitalized infants and children with fever

OBJECTIVE

To determine the accuracy of C-reactive protein (CRP) for diagnosing serious bacterial and bacterial infections in infants and children presenting with fever.

STUDY DESIGN

Systematic review of diagnostic accuracy studies. We included studies comparing the diagnostic accuracy of CRP with microbiologic confirmation of (a) serious bacterial and (b) bacterial infection.

RESULTS

For differentiating between serious bacterial infection and benign or nonbacterial infection (6 studies), the pooled estimate of sensitivity was 0.77 (95% CI, 0.68, 0.83); specificity, 0.79 (95% CI, 0.74, 0.83); positive likelihood ratio, 3.64 (95% CI, 2.99, 4.43); and negative likelihood ratio, 0.29 (95% CI, 0.22, 0.40). In multivariate analysis, CRP is an independent predictor of serious bacterial infection. 3 studies investigating the accuracy of CRP for diagnosing bacterial infection could not be pooled, but all showed a lower sensitivity compared with studies using serious bacterial infection as the reference diagnosis.

CONCLUSIONS

CRP provides moderate and independent information for both ruling in and ruling out serious bacterial infection in children with fever at first presentation. Poor sensitivity means that CRP cannot be used to exclude all bacterial infection.

EBM journal clubs in general practice

The context of general practice makes the translation of evidence into clinical practice difficult. General practitioners interested in implementing evidence met at The Royal Australian College of General Practitioners' 2006 Annual Scientific Convention. We discussed evidence based medicine (EBM) journal club as a solution to this problem, including keys to success and barriers to overcome. The aim of this article is to provide suggestions for those wishing to set up their own EBM journal club. This will be supported as a Category 1 CPD activity by The Royal Australian College of General Practitioners in the 2008-2010 triennium.

Antibiotics for bronchiolitis in children

BACKGROUND

Bronchiolitis is a serious, potentially life-threatening respiratory illness commonly affecting young babies. It is most often caused by Respiratory Syncytial Virus (RSV). The diagnosis is usually made on clinical grounds (especially tachypnoea and wheezing in a child less than two years of age). Antibiotics are not recommended for bronchiolitis unless there is concern about complications such as secondary bacterial pneumonia. Despite this, they are used at rates of 34 to 99% in uncomplicated cases.

OBJECTIVES

To evaluate the use of antibiotics for bronchiolitis.

SEARCH STRATEGY

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) which includes the Acute Respiratory Infection Groups' specialised register, the Database of Abstracts of Reviews of Effects (DARE) (The Cochrane Library Issue 3, 2006); MEDLINE (January 1966 to August Week 2, 2006); EMBASE (1990 to March 2006); and Current Contents (2001 to September 2006).

SELECTION CRITERIA

Types of studies: single or double blind randomised controlled trials comparing antibiotics to placebo in the treatment of bronchiolitis.

TYPES OF PARTICIPANTS

children under the age of two years diagnosed with bronchiolitis using clinical criteria (including respiratory distress preceded by coryzal symptoms with or without fever). Types of interventions: oral, intravenous, intramuscular or inhaled antibiotics versus placebo. Types of outcome measures: primary clinical outcomes: time for the resolution of symptoms/signs (pulmonary markers: respiratory distress; wheeze; crepitations; oxygen saturation; and fever).

SECONDARY OUTCOMES

hospital admissions; time to discharge from hospital; re-admissions; complications/adverse events developed; and radiological findings.

DATA COLLECTION AND ANALYSIS

All data were analysed using Review Manager software, version 4.2.7.

MAIN RESULTS

One study met our inclusion criteria. It randomised children presenting clinically with bronchiolitis to either ampicillin or placebo. The main outcome measure was duration of illness and death. There was no significant difference between the two groups for length of illness and there were no deaths in either group.

AUTHORS' CONCLUSIONS

This review found no evidence to support the use of antibiotics for bronchiolitis. This results needs to be treated with caution given only one RCT justified inclusion. It is unlikely that simple RCTs of antibiotics against placebo for bronchiolitis will be undertaken in future. Research to identify a possible small subgroup of patients presenting with bronchiolitis-like symptoms who may benefit from antibiotics may be justified. Otherwise, research may be better focussed on determining the reasons for clinicians to use antibiotics so readily for bronchiolitis, and ways of reducing their anxiety, and therefore their use of antibiotics for bronchiolitis.

Diagnostic accuracy of cystatin C compared to serum creatinine for the estimation of renal dysfunction in adults and children--a meta-analysis

OBJECTIVES

To perform a systematic review comparing the diagnostic accuracy of CysC with SCr.

METHODS

MEDLINE and EMBASE (January 1984-February 2006) were searched. Studies included i) evaluated CysC against a recognised 'gold standard' method for determining GFR using a receiver operating characteristics (ROC) curve analysis and ii) included data that could be extracted into a 2x2 table.

RESULTS

The search identified 27 population groups in 24 studies (n=2007) that compared the diagnostic accuracy of CysC with SCr. The diagnostic odds ratios (DORs) (95% CI) of predicting renal dysfunction derived from a Moses-Littenberg linear regression model were 3.99 (3.41-4.57) for CysC and 2.79 (2.12-3.46) for SCr.

CONCLUSION

The diagnostic accuracy for impaired renal function favours CysC. However, the confidence intervals for the pooled DORs for the biomarkers overlap. The ability of CysC (cut-off values between 0.9 and 1.4 mg/L) to rule in renal impairment (as measured by inulin-determined GFR of 60-79 mL/min/1.73 m2) in persons in whom this is suspected is large and conclusive.

The role of BNP testing in heart failure

Brain natriuretic peptide (BNP) levels are simple and objective measures of cardiac function. These measurements can be used to diagnose heart failure, including diastolic dysfunction, and using them has been shown to save money in the emergency department setting. The high negative predictive value of BNP tests is particularly helpful for ruling out heart failure. Treatment with angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, spironolactone, and diuretics reduces BNP levels, suggesting that BNP testing may have a role in monitoring patients with heart failure. However, patients with treated chronic stable heart failure may have levels in the normal range (i.e., BNP less than 100 pg per mL and N-terminal proBNP less than 125 pg per mL in patients younger than 75 years). Increases in BNP levels may be caused by intrinsic cardiac dysfunction or may be secondary to other causes such as pulmonary or renal diseases (e.g., chronic hypoxia). BNP tests are correlated with other measures of cardiac status such as New York Heart Association classification. BNP level is a strong predictor of risk of death and cardiovascular events in patients previously diagnosed with heart failure or cardiac dysfunction.

Is pulse palpation helpful in detecting atrial fibrillation? A systematic review

BACKGROUND

Atrial fibrillation in the elderly is common and potentially life threatening. The classical sign of atrial fibrillation is an irregularly irregular pulse.

OBJECTIVE

The objective of this research was to determine the accuracy of pulse palpation to detect atrial fibrillation.

METHODS

We searched Medline, EMBASE, and the reference lists of review articles for studies that compared pulse palpation with the electrocardiogram (ECG) diagnosis of atrial fibrillation. Two reviewers independently assessed the search results to determine the eligibility of studies, extracted data, and assessed the quality of the studies.

RESULTS

We identified 3 studies (2385 patients) that compared pulse palpation with ECG. The estimated sensitivity of pulse palpation ranged from 91% to 100%, while specificity ranged from 70% to 77%. Pooled sensitivity was 94% (95% confidence interval [CI], 84%-97%) and pooled specificity was 72% (95% CI, 69%-75%). The pooled positive likelihood ratio was 3.39, while the pooled negative likelihood ratio was 0.10.

CONCLUSIONS

Pulse palpation has a high sensitivity but relatively low specificity for atrial fibrillation. It is therefore useful for ruling out atrial fibrillation. It may also be a useful screen to apply opportunistically for previously undetected atrial fibrillation. Assuming a prevalence of 3% for undetected atrial fibrillation in patients older than 65 years, and given the test's sensitivity and specificity, opportunistic pulse palpation in this age group would detect an irregular pulse in 30% of screened patients, requiring further testing with ECG. Among screened patients, 0.2% would have atrial fibrillation undetected with pulse palpation.

Identifying health centers in honduras infested with Rhodnius prolixus using the seroprevalence of Chagas disease in children younger than 13 years

The objective of this study is to determine if a Chagas disease protocol starting with a serological survey is as reliable at identifying insect-infested areas as one using the gold standard entomological survey. The study found that health center areas infested with Rhodnius prolixus were identified using a threshold seroprevalence of 0.1%. The serological survey took half the time and was 30% less expensive than the entomological survey. Developing countries with limited resources may find this strategy useful in combating Chagas disease. This strategy also identifies seropositive children, which facilitates their treatment.

A systematic review of brachytherapy. Is it an effective and safe treatment for localised prostate cancer?

BACKGROUND

Brachytherapy is a promising treatment for prostate cancer as it may have reduced rates of impotence and incontinence.

OBJECTIVE

General practitioners can influence the treatment patients receive by their referral patterns, so it is important they understand the effectiveness and safety of treatment. We reviewed the primary literature on brachytherapy as sole therapy for localised prostate cancer.

DISCUSSION

Although there have been many studies on the safety and effectiveness of brachytherapy, there have been no trials of brachytherapy versus other treatments that would control for factors such as tumour stage, grade, or initial prostate specific antigen levels. Brachytherapy for localised prostate cancer appears to have equivalent survival rates to surgery and lower rates of impotence and urinary incontinence.

Promoting better use of the PSA test in general practice: randomized controlled trial of educational strategies based on outreach visits and mailout

BACKGROUND

Prostate-specific antigen (PSA) testing for prostate cancer is controversial. Demand for PSA testing is likely to rise in the UK, Australia and other western countries. Primary care needs to develop appropriate strategies to respond to this demand.

OBJECTIVES

Our aim was to compare the effectiveness of educational outreach visits (EOVs) and mailout strategies targeting PSA testing in Australian primary care.

METHODS

A randomized controlled trial was conducted in general practices in southern Adelaide. The main outcome measures at baseline, 6 months and 12 months post-intervention were PSA testing rates and GP knowledge in key areas relating to prostate cancer and PSA testing.

RESULTS

The interventions were able to demonstrate a change in clinical practice. In the 6 months post-intervention, median PSA testing rate in the EOV group was significantly lower than in the postal group, which in turn was significantly lower than the control group (P < 0.001). Statistically significant differences were not, however, maintained in the 6-12 month post-intervention period. The EOV group, at 6 months follow-up, had a significantly greater proportion of "correct" responses than the control group to questions about prostate cancer treatment effectiveness (P = 0.004) and endorsement of PSA screening by professional bodies (P = 0.041).

CONCLUSIONS

Primary care has a central role in PSA testing for prostate cancer. Clinical practice in this area is receptive to evidence-based interventions.

Diagnostic and management strategies for anaemia in adults

BACKGROUND

Anaemia is often an incidental finding or is discovered when patients present with nonspecific symptoms such as tiredness.

OBJECTIVE

This article presents strategies to identify the cause of anaemia and uses four case studies to illustrate these principles.

DISCUSSION

Few diagnostic tests can completely rule in or rule out causes of anaemia. This makes the investigation of anaemia complex. An understanding of the limitations of tests in aiding diagnosis is required.