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PubMed2006

Institutional variability in the accuracy of urinary cytology for predicting recurrence of transitional cell carcinoma of the bladder.

OBJECTIVE: To assess the contemporary inter-institutional accuracy of urinary cytology in predicting the recurrence of transitional cell carcinoma (TCC) of the bladder, in a large multi-institutional cohort from four continents, as cystoscopy and urinary cytology represent the 'gold standards' for surveillance of TCC recurrences, but the ability of cytology to predict recurrence varies. PATIENTS AND METHODS: Ten institutions contributed 2542 patients with a history of superficial TCC, of whom 898 had TCC recurrence. Age- and gender-adjusted logistic regression models were used to evaluate the association between urine cytology and TCC recurrence. The predictive accuracy derived from the logistic regression model was tested using the area under the receiver operating characteristic curve. The resulting predictive accuracy estimates were internally validated with 200 bootstrap re-samples. RESULTS: The mean (range across institutions) age of the patients was 65 (48-69) years and 75 (67-87)% were men. Cytology was positive in 19 (10-38)% of patients; recurrence was identified in 35 (27-54)% of patients. The sensitivity was 38-65% across institutions. Urinary cytology varied significantly in its ability to predict recurrence of bladder cancer. Institution-specific predictive accuracy adjusted for gender and age was 0.627-0.893. Stratifying by grade and stage only partly attenuated the discrepancies between centres. CONCLUSIONS: The variability of urinary cytology results was very appreciable among the 10 centres and ranged from poor (63%) to excellent (89%).

Aged↗

PubMed2006

Circulating tumour-associated plasma DNA represents an independent and informative predictor of prostate cancer.

OBJECTIVE: To investigate whether preoperative plasma levels of free DNA can discriminate between men with localized prostate cancer and benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: In all, 161 referred patients suspicious for prostate cancer either by an elevated prostate-specific antigen (PSA) level and/or abnormal digital rectal examination (DRE) were included in this prospective study. Peripheral plasma was taken before prostate biopsy and genomic DNA was extracted from the plasma using the a commercial kit and a vacuum chamber. After controlling for age, PSA level, the percentage free/total (f/t) PSA and prostate volume, the median prostate cancer plasma DNA concentration served as diagnostic threshold in uni- and multivariate logistic regression models. Multivariate models were subjected to 200 bootstraps for internal validation and to reduce over-fit bias. RESULTS: Subgroups consisted of 142 men with clinically localized prostate cancer and 19 with BPH. The median plasma concentration of cell-free DNA was 267 ng/mL in men with BPH vs 709 ng/mL in men with prostate cancer. In univariate analyses, plasma DNA concentration was a statistically significant and informative predictor (P = 0.032 and predictive accuracy 0.643). In multivariate analyses, it remained statistically significant after controlling for age, tPSA, f/tPSA and prostate volume, increasing the predictive accuracy by 5.6%. CONCLUSIONS: Our data suggest that plasma DNA level is a highly accurate and informative predictor in uni- and multivariate models for the presence of prostate cancer on needle biopsy. The predictive accuracy was substantially increased by adding plasma DNA level. However, larger-scale studies are needed to further confirm its clinical impact on prostate cancer detection.

Adult↗

PubMed2006

African-American race is a predictor of prostate cancer detection: incorporation into a pre-biopsy nomogram.

OBJECTIVES: To construct a pre-biopsy predictive model incorporating several clinical variables, including African-American (AA) or Caucasian race, to predict the risk of prostate cancer detection on prostate biopsy, as traditionally AA men have had a higher incidence of prostate cancer than Caucasian men, but previous predictive tools for prostate cancer have not incorporated the effect of race. PATIENTS AND METHODS: We evaluated 9473 patients undergoing initial prostate biopsy at three equal-access healthcare institutes from 1993 to 2003. At each biopsy session, patient age, race, serum prostate-specific antigen level (PSA), digital rectal examination (DRE) findings, number of biopsy cores taken, year of biopsy, and pathological findings were recorded. A logistic regression model was constructed to evaluate predictors of cancer detection based on pre-biopsy variables. The model was internally validated using the bootstrap statistical method, and a nomogram was constructed. RESULTS: Prostate cancer was diagnosed in 1895 (33%) AA men and 991 (26%) Caucasians. AA men had a significantly higher mean serum PSA level than Caucasians, at 13.0 and 8.5 ng/mL, respectively (P < 0.001). The mean ages were similar between AA and Caucasian men (P = 0.23), but Caucasian men had a higher incidence of an abnormal DRE (P < 0.001). On multivariate analysis, age, race, year of biopsy, PSA level, DRE, and number of cores taken were all statistically significant (P < 0.001). Hazard ratios were (controlling for year of biopsy); age (1.30), Caucasian race (0.74), PSA level (1.47), DRE (1.75), and number of cores taken (1.19). The predicted model had a boot-strapped concordance index of 0.75. CONCLUSION: AA race remains an independent predictor of prostate cancer detection in men undergoing initial prostate biopsy. This nomogram is the first to individualise the risk by AA or Caucasian race in a predictive model for counselling men on their probability of having cancer at the time of their first biopsy.

Black or African American↗

PubMed2005

Obesity prevention: a proposed framework for translating evidence into action.

Obesity as a major public health and economic problem has risen to the top of policy and programme agendas in many countries, with prevention of childhood obesity providing a particularly compelling mandate for action. There is widespread agreement that action is needed urgently, that it should be comprehensive and sustained, and that it should be evidence-based. While policy and programme funding decisions are inevitably subject to a variety of historical, social, and political influences, a framework for defining their evidence base is needed. This paper describes the development of an evidence-based, decision-making framework that is particularly relevant to obesity prevention. Building upon existing work within the fields of public health and health promotion, the Prevention Group of the International Obesity Task Force (IOTF) developed a set of key issues and evidence requirements for obesity prevention. These were presented and discussed at an IOTF workshop in April 2004 and were then further developed into a practical framework. The framework is defined by five key policy and programme issues that form the basis of the framework. These are: (i) building a case for action on obesity; (ii) identifying contributing factors and points of intervention; (iii) defining the opportunities for action; (iv)evaluating potential interventions; and (v) selecting a portfolio of specific policies, programmes, and actions. Each issue has a different set of evidence requirements and analytical outputs to support policy and programme decision-making. Issue 4 was identified as currently the most problematic because of the relative lack of efficacy and effectiveness studies. Compared with clinical decision-making where the evidence base is dominated by randomized controlled trials with high internal validity, the evidence base for obesity prevention needs many different types of evidence and often needs the informed opinions of stakeholders to ensure external validity and contextual relevance.

Decision Making↗

PubMed1996

Is this finding relevant? Generalisation and epidemiology.

The decision about whether the findings from analytical epidemiological studies can be extrapolated to another setting is an important one. We discuss some of the issues involved in the process of generalisation. A critical systematic qualitative approach should be used. This involves an assessment of the internal validity of the study and of the nature of the study base. The study subject matter and choice of epidemiologic measure should be considered. A study base similar to the target population is essential if the study is descriptive or if there is concern about effect modifiers whose effects cannot be predicted. In addition, data from quantitative tests of study findings in different populations should be considered.

Data Interpretation, Statistical↗

PubMed2003

Evaluation of safety training for manual handling of people with disabilities in specialised group homes in Australia.

OBJECTIVE: This paper attempted to examine the question of whether 351 disability services workers in an Australian State Government agency given manual handling training had significantly lower injury rates from manual handling injuries a year post-training than a control group (n = 351) without the training. METHODS: Control group members were selected by stratified random sampling to closely match the intervention group. The measures employed were the number of reported manual handling injuries per 100 full-time equivalents by certain characteristics, frequency of incidents, mean workers' compensation cost, and mean compensated days. RESULTS: Training in manual handling methods significantly reduced the risk by as much as 42%, with an average rate of 49.6 per 100 full-time equivalents (95% confidence interval 44.4-55.0) among the intervention group compared with 84.8 per 100 full-time equivalents (95% confidence interval 76.0-94.1) among controls. The risk differential was consistent across gender, age group, length of service, and job classification. However, in two injury categories (client lift/transfer and general manual handling), the intervention group had a marginally higher risk. The average workers' compensation cost in the control group was 4.2 times that in the intervention group. CONCLUSION: While the study has some weaknesses, overall, there is little evidence to suggest that the outcome observed was due to threats to internal validity. It is expected that the findings can encourage further evaluation studies of workplace safety training programs.

Adult↗

PubMed2005

Infections after coronary artery bypass graft surgery in Victorian hospitals--VICNISS Hospital Acquired Infection Surveillance.

OBJECTIVE: To establish a surveillance program reporting surgical site infection rates after coronary artery bypass graft surgery (CABGS) in Victorian public hospitals. METHODS: The VICNISS Coordinating Centre was established in 2002 to implement and co-ordinate a standardised surveillance system for hospital-acquired infections in acute care Victorian public hospitals. Using validated definitions and methodology from the Centers for Disease Control and Prevention's National Nosocomial Infection Surveillance (NNIS) program, data on risk-adjusted surgical site infection (SSI) rates were collected and submitted to the Coordinating Centre for collation and reporting. RESULTS: Six large Melbourne metropolitan hospitals contributed data for CABGS for the period 11 November 2002 to 30 June 2004, comprising a total of 3,482 patient records. Of 3,398 complete records, the aggregate SSI rates per 100 procedures for NNIS risk category 1 and 2 were 4.4 (95% Cl 3.7-5.3) and 6.0 (95% Cl 4.5-7.8) respectively. The deep sternal SSI rates were 0.6 (95% Cl 0.4-1.3) and 0.5 (95% Cl 0.5-2.4 for patients in risk category 1 and 2 respectively. The most common pathogen identified was Staphylococcus aureus. CONCLUSION: This early data from VICNISS demonstrates similar CABGS SSI rates to those reported by NNIS in the USA, but higher than reported by the German Nosocomial Infection Surveillance System. IMPLICATIONS: The adoption of a statewide, co-ordinated surveillance program using validated internationally accepted methodologies allows hospitals to benchmark their infection rates against aggregate local and international data and to examine infection prevention interventions.

Adult↗

PubMed2005

Pharmacoeconomics--an aid to better decision-making.

OBJECTIVES: The first aim of this workshop was to define pharmacoeconomic concepts and terminology. Pharmacoeconomics can be defined as the branch of economics that uses cost-benefit, cost-effectiveness, cost-minimization, cost-of-illness and cost-utility analyses to compare pharmaceutical products and treatment strategies. Economic evaluations provide healthcare decision-makers with valuable information, allowing optimal allocation of limited resources. However, pharmacoeconomics is based on long-term benefits, whereas physicians are typically forced to seek immediate savings. The second aim was to review pharmacoeconomic studies in the field of onychomycosis and finally to discuss future perspectives. RESULTS AND CONCLUSIONS: We discussed current pharmacoeconomic issues on the management of onychomycosis. Consensus was reached on the following issues: * Published pharmacoeconomic studies concerning onychomycosis are flawed. Future studies should be based on internationally validated principles and appropriate models. The fact that costs of different drugs, laboratory examinations and physician visits vary worldwide should be considered. Cost-benefit studies are required. * The National Institute for Clinical Excellence (NICE) recommendations are often considered in countries other than the UK, even when not adapted to the country in question. * Generic drugs might reduce costs, but this depends on their effectiveness (bioavailability). * Sampling requests affect the economic cost (dependent on methodology, which depends on country) and physicians often trust their instincts even when tests are repeatedly negative. * The cost of adverse event management is usually considered to be 10%; this may be too high for onychomycosis, as treatments are relatively safe without severe side-effects. * Probability of recurrence for each drug should be determined. * Need for disease severity standardization, definition of diagnostic criteria and successful treatment (mycological and clinical cure).

Antifungal Agents↗

PubMed2005

Patients' preferences for technical versus interpersonal quality when selecting a primary care physician.

OBJECTIVE: To assess patients' use of and preferences for information about technical and interpersonal quality when using simulated, computerized health care report cards to select a primary care provider (PCP). DATA SOURCES/STUDY SETTING: Primary data collected from 304 adult consumers living in Los Angeles County in January and February 2003. STUDY DESIGN/DATA COLLECTION: We constructed computerized report cards for seven pairs of hypothetical individual PCPs (two internal validity check pairs included). Participants selected the physician that they preferred. A questionnaire collected demographic information and assessed participant attitudes towards different sources of report card information. The relationship between patient characteristics and number of times the participant selected the physician who excelled in technical quality are estimated using an ordered logit model. PRINCIPAL FINDINGS: Ninety percent of the sample selected the dominant physician for both validity checks, indicating a level of attention to task comparable with prior studies. When presented with pairs of physicians who varied in technical and interpersonal quality, two-thirds of the sample (95 percent CI: 62, 72 percent) chose the physician who was higher in technical quality at least three out of five times (one-sample binomial test of proportion). Age, gender, and ethnicity were not significant predictors of choosing the physician who was higher in technical quality. CONCLUSIONS: These participants showed a strong preference for physicians of high technical quality when forced to make tradeoffs, but a substantial proportion of the sample preferred physicians of high interpersonal quality. Individual physician report cards should contain ample information in both domains to be most useful to patients.

Adult↗

PubMed2006

Application of regression-discontinuity analysis in pharmaceutical health services research.

OBJECTIVE: To demonstrate how a relatively underused design, regression-discontinuity (RD), can provide robust estimates of intervention effects when stronger designs are impossible to implement. DATA SOURCES/STUDY SETTING: Administrative claims from a Mid-Atlantic state Medicaid program were used to evaluate the effectiveness of an educational drug utilization review intervention. STUDY DESIGN: Quasi-experimental design. DATA COLLECTION/EXTRACTION METHODS: A drug utilization review study was conducted to evaluate a letter intervention to physicians treating Medicaid children with potentially excessive use of short-acting beta(2)-agonist inhalers (SAB). The outcome measure is change in seasonally-adjusted SAB use 5 months pre- and postintervention. To determine if the intervention reduced monthly SAB utilization, results from an RD analysis are compared to findings from a pretest-posttest design using repeated-measure ANOVA. PRINCIPAL FINDINGS: Both analyses indicated that the intervention significantly reduced SAB use among the high users. Average monthly SAB use declined by 0.9 canisters per month (p<.001) according to the repeated-measure ANOVA and by 0.2 canisters per month (p<.001) from RD analysis. CONCLUSIONS: Regression-discontinuity design is a useful quasi-experimental methodology that has significant advantages in internal validity compared to other pre-post designs when assessing interventions in which subjects' assignment is based on cutoff scores for a critical variable.

Bronchodilator Agents↗

PubMedDate not supplied

Collection of health-economic data alongside clinical trials: is there a future for piggyback evaluations?

OBJECTIVE: The objective of this article is to discuss issues surrounding the conduct of "piggyback evaluations," in which health-economic data are collected within an otherwise typical clinical trial. METHODS: We review the methodologic literature on piggyback economic evaluations, as well as selected empiric studies. We summarize the challenges encountered in the conduct of these studies, alternative ways of addressing these challenges, and their future role in pharmacoeconomic research. RESULTS: Piggyback evaluations have certain advantages over other types of pharmacoeconomic studies. An economic evaluation can benefit from the experimental design that maximizes the trial's internal validity, and it is often more practical to collect economic data alongside a trial rather than to fund a stand-alone economic study. However, piggyback evaluations are subject to problems deriving from the competing nature of clinical versus economic study objectives, which can give rise to tension in such fundamental aspects of study design as the selection of study subjects and sites; the extent of protocol-mandated health-care services; and the determination of sample size, length of follow-up, and the study comparator(s). Many solutions have been put forth in the literature to address these challenges. CONCLUSIONS: Piggyback evaluations can be an appropriate means to measure the economic impact of medical interventions, provided that the methodologic challenges are acknowledged and addressed within the context of each individual study. As long as a desire for patient-level data from clinical trials exists, there will be a need for piggyback economic evaluations in the future.

Clinical Protocols↗

PubMed2005

Best practices for elderly hip fracture patients. A systematic overview of the evidence.

OBJECTIVES: To determine evidence-based best practices for elderly hip fracture patients from the time of hospital admission to 6 months postfracture. DATA SOURCES: MEDLINE, Cochrane Library, CINAHL, Embase, PEDro, Ageline, NARIC, and CIRRIE databases were searched for potentially eligible articles published between 1985 and 2004. REVIEW METHODS: Two independent reviewers determined studies appropriate for inclusion using standardized selection criteria, extracted data, evaluated internal validity, and then rated studies according to levels of evidence. Only Level 1 or 2 evidence was included in our summary of clinical recommendations. RESULTS: Spinal anesthesia, pressure-relieving mattresses, perioperative antibiotics, and deep vein thromboses prophylaxes had consistent evidence of benefit. Routine preoperative traction was not associated with any benefits and should be abandoned. Types of surgical management, postoperative wound drainage, and even "multidisciplinary" care, lacked sufficient evidence to determine either benefit or harm. There was little evidence to either determine best subacute rehabilitation practices or to direct ongoing medical issues (e.g., nutrition). Studies conducted during the subacute recovery period were heterogeneous in terms of treatment settings, interventions, and outcomes studied and had no clear evidence for best treatment practices. CONCLUSIONS: The evidence for perioperative practices is relatively robust and evidence-based perioperative treatment guidelines can be easily established. Conversely, more evidence is required to better guide the care of elderly patients with hip fracture during the subacute recovery period and convalescence.

Aged↗

PubMed2005

Behavioral research and the double-blind placebo-controlled methodology: challenges in applying the biomedical standard to behavioral headache research.

The randomized, double-blind, placebo-controlled experimental design has prevailed as the "gold standard" in biomedical research, intended to control potential bias in patient/group assignment, investigator allegiance, patient expectations, and nonspecific therapeutic effects. Properly executed, such designs ensure a study's internal validity and allow differential group outcomes to be attributed to the active treatment. These controlled trials generally yield more conservative outcomes than open trials and case reports and establish efficacy in pharmaceutical research. In meta-analytic reviews, studies are often assigned quality scores based in part on the degree to which they meet this scientific standard. Applying the biomedical research design standards for blinding and placebo control to clinical trials evaluating behavioral and other nonpharmacologic headache treatment nearly always is either infeasible or simply not possible. Only rarely is blinding meaningfully achievable in administration of behavioral or psychological therapies. Various "psychological placebo" control conditions have been forwarded in behavioral studies (eg, sham treatments, pseudomeditation), but these controls are incapable of emulating an inert control condition comparable to that of the pill placebo in pharmacologic research, and they are best reserved for studies examining the mechanisms whereby an intervention produces improvement. This article reviews the conceptual and procedural challenges in applying the standard pharmaceutical clinical trials research design to behavioral headache research as well as implications for meta-analyses across studies of various treatment modalities.

Behavior Therapy↗

PubMed2005

Efficacy and effectiveness approaches in behavioral treatment trials.

The objective is to clarify the distinction between efficacy and effectiveness approaches and to discuss how these approaches can be used in a complementary way in the development, evaluation, and implementation of behavioral treatments for primary headache in various settings. Efficacy studies, with an emphasis on internal validity, are experiments that evaluate treatment response in an ideal, highly controlled research environment. Despite their methodological strengths, efficacy studies are limited in their ability to estimate the treatment effects that can be expected in clinical practice settings. Effectiveness studies, with an emphasis on external validity, are outcome studies with less controls that evaluate treatment response in settings more representative of clinical practice. Effectiveness studies, however, are limited in their ability to determine the causal link between treatment and response. Based on the four-phase model used in new drug development, a three-phase linear progression model is presented for behavioral treatment studies. This model provides for pilot testing, efficacy testing, and effectiveness testing of behavioral treatments so that there is appropriate evaluation from initial promise of a developing treatment to implementation and dissemination to various treatment delivery settings.

Behavior Therapy↗

PubMed2006

A systematic review of the efficacy and safety of atypical antipsychotics in patients with psychological and behavioral symptoms of dementia.

Although the Food and Drug Administration (FDA) has not approved atypical antipsychotics for use in patients with dementia, they are commonly prescribed in this population. Recent concerns about increased risk of cerebrovascular events and mortality have led to warnings. A systematic review was conducted to assess the benefits and harms of atypical antipsychotics when used in patients with behavioral and psychological symptoms of dementia. Electronic searches (through March 2005) of the Cochrane Library, Medline, Embase, and PsycINFO were supplemented with hand searches of reference lists, dossiers submitted by pharmaceutical companies, and a review of the FDA Website and industry-sponsored results database. Using predetermined criteria, each study was assessed for inclusion, and data about study design, population, interventions, and outcomes were abstracted. An overall quality rating (good, fair, or poor) was assigned based on internal validity. The evidence for olanzapine and risperidone supports their effectiveness compared with placebo. Short-term adverse events were similar to placebo. Risperidone had no advantage over haloperidol on efficacy measures in the better-quality studies. Risperidone had an advantage over haloperidol on some measures of extrapyramidal symptoms. Evidence for the other atypical antipsychotics is too limited to assess efficacy and safety. Trials were short term and conducted in highly selected populations. The potential for increased risk of cerebrovascular adverse events and mortality is a serious concern. To make judgments about when the benefits of atypical antipsychotics outweigh the potential harms, clinicians need more information. Additional data from existing trials and more-complete reporting of trial results could provide this information.

Alzheimer Disease↗

PubMed2005

What is a life worth? Robustness of VSL values from contingent valuation surveys.

The value of a statistical life (VSL) is a key input for estimating the benefits of policies that save lives. Several recent studies have obtained estimates of the VSL from contingent valuation surveys, i.e., by asking people to say how much they would pay to reduce their risk of dying. This article examines statistical factors that may influence the estimates of the VSL obtained from such surveys. We examine the importance of distributional assumptions, the choice of the welfare statistics of interest, the procedure for computing them, outliers, undesirable response effects, and internal validity of the willingness-to-pay (WTP) responses. We illustrate the importance of these factors using dichotomous-choice and open-ended WTP data from four recent contingent valuation surveys.

Journal Article↗

PubMedDate not supplied

Pulsatile versus nonpulsatile cardiopulmonary bypass flow: an evidence-based approach.

OBJECTIVE: To derive evidence-based recommendations for the use of pulsatile perfusion (PP) technique for the reduction of mortality and nonfatal complications after elective coronary artery bypass grafting surgery (CABG). OUTCOMES: Incidence of total mortality, myocardial infarction (MI), stroke, and renal failure during hospital stay. EVIDENCE: Medline, Embase, and the Cochrane controlled trial register (CCTR) on the Cochrane library were searched from the earliest achievable date of each database to March 2005. No language restrictions were applied. Retrieved reprints were evaluated according to a priori inclusion criteria, and those included were critically appraised using established internal validity criteria. BENEFITS AND HARMS: Only one fair quality randomized controlled trial demonstrated the beneficial effect of PP in reducing the incidence of total mortality and MI. No studies demonstrated the beneficial effect of PP in reducing the incidence of stoke or renal failure. One randomized controlled trial demonstrated that PP was associated with increased hemolysis compared to nonpulsatile (NP) perfusion. CONCLUSION: The evidence is conflicting and therefore does not support making recommendation for or against routinely providing the PP to reduce the incidence of mortality or MI. The evidence is insufficient to recommend for or against routinely providing the pulsatile profusion to reduce the incidence of stroke or renal failure.

Cardiopulmonary Bypass↗

PubMed1989

Dimensional approach to infantile autism in mentally retarded adults.

By use of latent trait models, a 7-item autism rating scale was established, based on the Medical Research Council's Schedule of Handicaps, Behaviours and Skills. Data from a community-based sample of 302 mentally retarded adults were assigning good internal validity to the autism scale, and revealing a distribution of symptoms consistent with dimensional, rather than categorical, distribution of infantile autism. A total of 23 (7.6%) of the sample were earlier diagnosed as suffering from infantile autism. Using this clinical diagnosis as a reference, the autism rating scale, with a cut-off point at greater than or equal to 2, established diagnoses with a sensitivity of 0.83 and specificity of 0.89.

Adult↗