Doin' the twist: new tools for an old concept of myocardial function.

It has been known for some time that the heart rotates during the cardiac cycle in concert with radial and longitudinal motion. With advances in imaging technology, it has been appreciated that the apex and base of the heart rotate in different directions, resulting in a twisting or torsional motion. A new echocardiographic technique, "speckle tracking imaging", permits accurate quantification of this motion. Torsion as well as the timing and magnitude of the rate of torsion (torsional velocity) may provide important new insights into cardiac physiology and disease.

Prospective assessment of the diagnostic and therapeutic impact of small-bowel push enteroscopy.

BACKGROUND AND STUDY AIMS: Although the reported diagnostic yield of push enteroscopy has been substantial in previous studies, its clinical impact has never been prospectively evaluated. The primary aim of this study was to prospectively determine the diagnostic and therapeutic impact of enteroscopy. In addition, the yield of new and clinically important findings was prospectively assessed. PATIENTS AND METHODS: Consecutive patients referred for enteroscopy were studied. The referring clinician completed a form indicating the working diagnosis, degree of diagnostic certainty, and the management plan had enteroscopy been unavailable. Diagnostic certainty was indicated on a scale of 1 = very unlikely (1 - 9 %) to 6 = certain (100 %). Following enteroscopy, the referring doctor completed another form indicating these features in the light of the enteroscopic findings. RESULTS: The study group comprised 77 patients referred for 79 push enteroscopies. There was a change in working diagnosis or management plan as a result of enteroscopy in 39/77 (51 %) patients. The working diagnosis and the management plan changed in 29/77 (38 %) and 34/77 (44 %), respectively, and the diagnostic certainty changed in a further 29 patients (38 %). There were clinically significant small-bowel findings in 16 (20 %) and new upper gastrointestinal findings in 16 (20 %), giving an overall diagnostic yield of 40 %. CONCLUSIONS: Enteroscopy has a significant impact on clinicians' working diagnoses and management plans.

On patient judgement.

Clinical judgement, the keystone of medical expertise, is a hot topic. By contrast, patient judgement, also of central importance in health care, receives little attention. Patients have the last say concerning whether or not they seek medical treatment for symptoms, follow a doctor's advice or accept reassurance. Delay in seeking help for serious symptoms, non-compliance with treatment advice and failure of doctors to reassure many of the 'worried well' have long been recognized as serious problems. We argue that what is common to these important problems is patient judgement. Surveys yielding information about the average influence of a large number of individual variables do not do justice to the complex interaction of influences that can influence the judgements of an individual person under particular social circumstances. This is what explains the wide variety of patient reactions. From the medical standpoint, such unpredictable patient behaviour seems irrational. The patient perspective on the meaning of their actions is a hiatus in our knowledge, which is hampering the planning of effective interventions. Too few studies have sought the perspective of patients by asking them why they acted as they did. Thus, the wide spectrum of patient response in these situations in relation to personality, life experience and social context cannot be studied without interpretive field studies that include interview of patients with qualitative interpretation.

Quality assurance and technology assessment: pieces of a larger puzzle.

Increasing integration of health care and health services research has resulted in an overlap between disciplines involved in the evaluation of clinical practice. We have examined the relationships of quality assurance (QA), medical technology assessment (TA), clinical epidemiology (CE) and evidence-based medicine (EBM) from an historical perspective. Clinicians, patients and administrators need local information on effectiveness of routine care. Information from trials alone, efficacy data, will not suffice nor can it be culled from administrative databases designed for other purposes. The current activities of QA should be therefore be expanded to include the study of the effectiveness of interventions in terms of appropriateness of use, patient outcomes and study of the determinants of outcomes, as seen from the perspective of doctors, patients, administrators and policy makers, using data collected during the course of routine patient care. With the assistance of information technology, with methodological support and multidisciplinary cooperation, clinicians can do this as part of a more broadly defined clinical research. Quality assurance and TA both evolved with the objective of studying clinical care but have quite different historical roots, complementary perspectives and objectives, use different methods and involve a different set of practitioners. Quality assurance is a type of 'formative' evaluation conducted in the clinical setting using indicators as flags of process or outcome events of interest, simple surveys and audit studies. Its primary aim is to achieve incremental improvement rather than to simply pass judgement. An important underlying assumption is that health care behaves as a complex dynamic system. Technology assessment, a form of summative evaluation with an orientation towards policy, synthesises information from formal scientific studies of efficacy in the form of clinical trials and studies of cost-effectiveness. For the evaluation of the impact of any technology more complex than a drug, the complementary contributions of both of these disciplines is needed, and QA and TA should work cooperatively in tandem with the support of CE and EBM.

The anatomy and relations of evidence-based medicine.

Current tensions between evidence-based medicine (EBM) and some clinicians are counterproductive and unnecessary. The most contentious issues concern (a) the limitations of efficacy data from randomised trials as evidence; (b) differences in attitudes to medical diagnosis and clinical judgement; and (c) political concerns about the use of the concept of clinical evidence and guidelines to restrict physician autonomy. Health services research has evolved in response to a bureaucratic need to study health care, including clinical practice, in order to improve its effectiveness (defined mainly in terms of technological interventions), and to contain costs. Its perspective is from the top-down representing the interests of bureaucracy and managed care, and articulates with political demands for professional accountability and cost-containment. EBM has established its place as an important contributor to the methodological toolbox for health services research. There is a need for a corresponding coherent programme of clinical practice research which would locate EBM in the clinical environment beside quality assurance, the study of the appropriateness and effectiveness of interventions, and multidisciplinary research related to the art of medicine and supportive aspects of clinical care. EBM would then be seen as one organ in relation to many others making their contribution to the body of knowledge needed for clinical decisions and policy making. A 'centre for the study of clinical practice' would be an appropriate structure to support such a comprehensive programme of clinical practice research in a tertiary hospital. The bottom-up perspective of clinical practice research would complement the current top-down perspective of most health services research, providing information to doctors, patients and administrators concerning local quality of care and health outcomes, information which could also be aggregated for guidance of health policy makers. It would also represent the voice of the clinician in policy debates. Such a programme, located in the practice environment, would also foster mutual understanding, respect and cooperation between workers from different backgrounds.

In-hospital mortality after transurethral resection of the prostate in Victorian public hospitals.

BACKGROUND: The purpose of the present paper was (i) to identify trends in in-hospital mortality after transurethral resection of the prostate (TURP) in Victorian public hospitals; and (ii) to explore associations between in-hospital mortality after TURP and age, adverse events, type of admission (emergency/planned), location of the hospital (metropolitan/rural), teaching status of the hospital and length of stay. METHODS: Trends in in-hospital mortality after TURP and the associations between in-hospital mortality and the aforementioned variables were studied using International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) coded Victorian hospital morbidity data from public hospitals between 1987-88 and 1994-95. Crude and adjusted odds ratios (OR) and 95% confidence intervals (CI) were based on univariate and multivariate logistic regression, respectively. RESULTS: After adjustment for age, comorbidity, and other confounding variables, the trend in mortality reduction over time was highly significant (P for trend < 0.0001, 95% CI for trend: 0.84-0.95). Highly significant associations with mortality were observed for emergency admissions (OR = 1.99, P < 0.0001), presence of adverse events (OR = 2.69, P < 0.0001), length of hospital stay (P for trend < 0.0001, 95% for trend: 1.88-2.15) and age (P for trend < 0.0001; 95% CI for trend: 1.26-1.48). CONCLUSIONS: Routinely collected data from hospitals can provide tentative evidence of improved effectiveness of a surgical treatment, provided analysis takes careful account of potential sources of bias, especially those related to possible changes in case selection over time. These kinds of data should stimulate a joint effort between clinicians, quality assurance experts and epidemiologists to confirm this attribution, and to locate the causative factors.

Inter-hospital comparison of mortality rates.

OBJECTIVE: To compare crude and adjusted in-hospital mortality rates after prostatectomy between hospitals using routinely collected hospital discharge data and to illustrate the value and limitations of using comparative mortality rates as a surrogate measure of quality of care. METHODS: Mortality rates for non-teaching hospitals (n = 21) were compared to a single notional group of teaching hospitals. Patients age, disease (comorbidity), length of stay, emergency admission, and hospital location were identified using ICD-9-CM coded Victorian hospital morbidity data from public hospitals collected between 1987/88 and 1994/95. Comparisons between hospitals were based on crude and adjusted odds ratios (OR) and 95% confidence intervals (CI) derived using univariate and multivariate logistic regression. Model fit was evaluated using receiver operating characteristic curve i.e. statistic, Somer's D, Tau-a, and R2. RESULTS: The overall crude mortality rates between hospitals achieved borderline significance (alpha2=31.31; d.f.=21; P=0.06); these differences were no longer significant after adjustment (chi2=25.68; P=0.21). On crude analysis of mortality rates, four hospitals were initially identified as 'low' outlier hospitals; after adjustment, none of these remained outside the 95% CI, whereas a new hospital emerged as a 'high' outlier (OR=4.56; P= 0.05). The adjusted ORs between hospitals compared to the reference varied from 0.21 to 5.54, ratio = 26.38. The model provided a good fit to the data (c=0.89; Somer's D= (0.78; Tau-a = 0.013; R2= 0.24). CONCLUSIONS: Regression adjustment of routinely collected data on prostatectomy from the Victorian Inpatient Minimum Database reduced variance associated with age and correlates of illness severity. Reduction of confounding in this way is a move in the direction of exploring differences in quality of care between hospitals. Collection of such information over time, together with refinement of data collection would provide indicators of change in quality of care that could be explored in more detail as appropriate in the clinical setting.

Adverse events after prostatectomy in Victorian public hospitals.

BACKGROUND: A retrospective analysis of data from the Victorian Inpatient Minimum Database (VIMD) was conducted to analyse trends in prostatectomy rates in Victorian public acute-care hospitals from 1989/90 to 1994/95. The study also sought to identify predictors of adverse events (AE) after prostatectomy, and to compare in-hospital complications between open prostatectomy and transurethral resection of prostate (TURP). METHODS: All patients who had undergone any prostatectomy were identified according to the relevant ICD-9-CM procedure codes (60.2-60.4) documented in the VIMD. The main outcome measures, AE, were identified using the ICD-9-CM supplementary classification of external cause of injury (E850-858, E870-876, E878-879, E930-949). The variables used as predictors were year of prostatectomy, type of admission (planned, emergency), location of the hospital (rural, metropolitan), type of procedure (TURP, open), and teaching status of the hospital. Crude and adjusted odds ratios (OR) were based on univariate and multivariate logistic regression. RESULTS: The rates of prostatectomies have significantly increased over the 6-year study period (P for trend < 0.0001). The percentage of AE after prostatectomy increased simultaneously from 6.1 to 12.9% (P < 0.0001). During the same period, the in-hospital mortality rate after prostatectomy decreased from 1.2 to 0.5%, and length of stay decreased from 10.3 to 6.1 days (Kruskal-Wallis P < 0.0001). The significant predictors of outcome were year of prostatectomy (P for trend < 0.0001), emergency admissions (OR = 1.57; P < 0.0001), metropolitan hospitals (OR = 0.81; P = 0.0003), non-teaching hospitals (OR = 0.78; P < 0.0001), and open prostatectomy (OR = 1.52; P = 0.04). More in-hospital complications were associated with open prostatectomy than with TURP. CONCLUSIONS: The rise in AE rate after prostatectomy is unlikely to reflect poor quality of care, because in the same period there was a significant decrease in in-hospital mortality after prostatectomy. A more likely explanation is heightened awareness of AE with a lower threshold for reporting such events. Important factors other than variations in quality of care can result in an increase in AE. Hence the reported increase should be interpreted with caution before attempting to conclude that changes in clinical practice could have a direct impact on these rates.

Challenges for the quality movement.

Recent developments in the control of the performance of the health system are making it increasingly important that effective quality systems are in place. However, there is significant evidence that many quality programmes are not effective, and, in particular, resistance by many medical and other clinical staff continues. It is, therefore, important for people concerned with the implementation of quality programmes to look at the reasons why quality efforts are not meeting expectations. Areas that need attention include the willingness to apply failure analysis to programmes, recognition of the characteristics of the professional service environment, and the implications for the organizational and management context of effective quality programmes.

Telemedicine in Australia. Recent developments.

There have been a number of important developments in Australia in the area of telemedicine. At the national level, the House of Representatives' Standing Committee on Family and Community Affairs has been conducting the Inquiry into Health Information Management and Telemedicine. The Australian Health Ministers' Advisory Council has supported the establishment of a working party convened by the South Australian Health Commission to prepare a detailed report on issues relating to telemedicine. State governments have begun a number of telemedicine projects, including major initiatives in New South Wales and Victoria and the extensive development of telepsychiatry services in Queensland. Research activities in high-speed image transmission have been undertaken by the Australian Computing and Communications Institute and Telstra, and by the Australian Navy. The matter of the funding of both capital and recurrent costs of telemedicine services has not been resolved, and issues of security and privacy of medical information are subjects to discussion. The use of the Internet as a universal communications medium may provide opportunities for the expansion of telemedicine services, particularly in the area of continuing medical education. A need has been recognized for the coordinated evaluation of telemedicine services as cost-benefit considerations are seen to be very important.

Initial qualitative evaluation of computed radiography in an intensive care unit.

The first computed radiography (CR) unit in Australia was installed at St Vincent's Hospital, Melbourne, in February 1994. An initial qualitative evaluation of the attitude of the intensive care unit (ICU) physicians to the CR unit was conducted in June 1994 by use of a survey. The results of the survey of ICU physicians indicated that images were available faster than under the previous system and that the use of the CR system was preferred to evaluate chest tubes and line placements. While it is recognized that a further detailed radiological evaluation of the CR system is required to establish the diagnostic performance of CR compared with conventional film, some comments on the implementation of the system and ICU physician attitudes to the CR system are put forward for consideration by other hospitals examining the possible use of CR systems.

Opening Pandora's box: the unpredictability of reassurance by a normal test result.

OBJECTIVES: To determine the rate of failure of patient reassurance after a normal test result and study the determinants of failure. DESIGN: Replicated single case study with qualitative and quantitative data analysis. SETTING: University teaching hospital. SUBJECTS: 40 consecutive patients referred for echocardiography either because of symptoms (10 patients) or because of a heart murmur (30). 39 were shown to have a normal heart. INTERVENTIONS: Medical consultations and semistructured patient interviews were tape recorded. Structured interviews with consultant cardiologists were recorded in survey form. MAIN OUTCOME MEASURES: Patient recall of the explanation and residual understanding, doubt, and anxiety about the heart after the test and post-test consultation. RESULTS: All 10 patients presenting with symptoms were left with anxiety about the heart despite a normal test result and reassurance by the consultant. Of 28 patients referred because of a murmur but shown to have no heart abnormality, 20 became anxious after detection of the murmur; 11 had residual anxiety despite the normal test result. CONCLUSIONS: Reassurance of the "worried well"-anxious patients with symptoms or patients concerned by a health query resulting from a routine medical examination or from screening-constitutes a large part of medical practice. It seems to be widely assumed that explaining that tests have shown no abnormality is enough to reassure. The results of this study refute this and emphasise the importance of personal and social factors as obstacles to reassurance.

Establishing thresholds for adverse patient outcomes.

OBJECTIVE: To establish thresholds for adverse patient outcomes in the absence of knowledge of patient illness severity indices. OUTCOMES: Pulmonary embolism, unplanned return to operating rooms, unplanned readmissions, clean and contaminated wound infections, and hospital-acquired bacteraemia. DESIGN: Analysis of results of surveys of hospitals in Australia by the Australian Council on Healthcare Standards following the introduction of clinical performance measures into the Accreditation process. SETTING: Acute care hospitals in Australia undergoing Accreditation surveys in 1993 and 1994. METHODS: Stratification of hospitals into small (1-99 beds), medium (100-199 beds), and large (> or = 200 beds), calculation of mean rates for the above outcomes in each group, and establishment of thresholds based on two standard errors from the mean. RESULTS: The mean rate of occurrence of incidents was higher for larger hospitals. Thresholds were generally lower for smaller and higher for larger hospitals. CONCLUSIONS: Bed-size is a useful index for "flagging" peer group variation. The methodological issues in establishing thresholds and their implications in monitoring the quality of care in hospitals are discussed.

Quantification of mitral regurgitation by integrated Doppler backscatter power.

OBJECTIVES: We attempted to determine whether continuous wave Doppler backscatter power could be used to quantify mitral regurgitation. BACKGROUND: The power of a Doppler backscatter signal is proportional to the number of scatterers insonated and, hence, to the moving volume of blood. The relative power of the continuous wave Doppler signals from mitral inflow and aortic outflow is therefore proportional to the relative volumes of blood in motion. METHODS: Computer postprocessing was used to derive the relative power of the Doppler backscatter signal from the intensity of the pixels within the spectral display of anterograde aortic and mitral flow. The power ratio was used to calculate the regurgitant fraction in 20 patients (mean age 61.4 years) with mitral regurgitation. This Doppler regurgitant fraction was compared with that derived from angiographic left ventricular volume and thermodilution cardiac output. In addition, 12 normal control subjects were studied by the Doppler method. RESULTS: Mean (+/- SD) catheterization regurgitant fraction was 0.50 +/- 0.26, and mean Doppler regurgitant fraction was 0.47 +/- 0.25 (r = 0.89). The limits of agreement between the two methods by Bland-Altman analysis were -0.21 + 0.27. In normal control subjects with an expected regurgitant fraction of close to zero, mean Doppler regurgitant fraction was 0.03 +/- 0.05. CONCLUSIONS: Doppler backscatter power from mitral and aortic inflow provides a new and accurate method for quantifying mitral regurgitation.

Left ventricular energy in mitral regurgitation: a preliminary report.

Energy exchange based on Newtonian principles is the most appropriate way to express the function of any pump--including the heart. Using information obtained at cardiac catheterisation, we have measured the total work energy (ET) of the left ventricle (LV) (mean 1.63 F) in patients with severe mitral regurgitation (mean regurgitant fraction 0.66). ET was approximately 84% above normal. Of the regurgitant energy (RE) (mean 0.95 F), on average , 3/4 (73.6%) was kinetic (KE) and 1/4 (23.4%) potential (PE). Both components represent wasted LV energy: the kinetic energy associated with turbulence lost as heat, the potential energy responsible for a rise in Left Atrial (LA) pressure. The amount of PE as a percentage of total regurgitant energy (RE) varied considerably from one patient to another (10.5% to 54.4%). Hence, colour flow mapping which detects only KE of turbulent jet flow must underestimate LV energy loss and, because of patient to patient variation, cannot consistently reflect severity of regurgitation. Measurements of PE correlate well with wedge P-wave height. Corresponding non-invasive estimates were made using sphygmodynamometer-calibrated indirect carotid pulse tracings and echocardiographic measurements. These were not significantly different from the invasive measurements. Unfortunately, the calculation of PE is indirect and involves subtraction, so that measurements for individual patients were not accurate enough for clinical use. Part of the non-invasive calculation involved an estimate of left atrial pressure based on the blood pressure measurement and Doppler velocity of regurgitation; this should be a useful measurement in itself.(ABSTRACT TRUNCATED AT 250 WORDS)

Two-dimensional Doppler echocardiographic flow imaging--exploration of clinical impact and problems.

Recent advances in electronic engineering have allowed Doppler echocardiography to be presented in the form of a real-time two-dimensional image. The resulting image of blood flow has been described as a 'non-invasive angiogram', but the analogy with angiography should not be pushed too far since the technical determinants of these images are entirely different. Nevertheless, the colour flow map does allow rapid and direct exclusion, detection and quantitation of regurgitant and stenotic lesions, and semi-quantitative assessment of valvular regurgitation and shunts. To achieve optimum results, it is necessary to standardise recording procedure, to take account of patient variables which influence the image appearance and quality and to be aware of the possibility of artefact. As for all investigations, results which are not coherent with other echocardiographic data, with other investigations and with the clinical assessment should be subjected to particular scrutiny with the possibility of false diagnosis in mind.