Biomedical subjects
Publications and source records attributed to A D Oxman.
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Health service users need reliable information to be able to make informed decisions. We evaluated the scientific quality of information presented at a large health fair in Oslo in 1995 and health-related articles in five newspapers during one week in the spring of 1995. The brochures scored consistently low on the index used to measure scientific quality. It was generally impossible to distinguish opinions from facts, or to assess the validity and consistency of the evidence underlying the conveyed information. Important consequences (benefits, risks and costs) were rarely assessed. Health-related articles in the lay press also scored low on the index. Minor changes could have led to marked improvement of some of the articles. It is important to improve the ability of journalists and producers of brochures to appraise their work in a critical light.
OBJECTIVE: To determine the effectiveness of different types of interventions in improving health professional performance and health outcomes. DATA SOURCES: MEDLINE, SCISEARCH, CINAHL and the Research and Development Resource Base in CME were searched for trials of educational interventions in the health care professions published between 1970 and 1993 inclusive. STUDY SELECTION: Studies were selected if they provided objective measurements of health professional performance or health outcomes and employed random or quasi-random allocation methods in their study designs to assign individual subjects or groups. Interventions included such activities as conferences, outreach visits, the use of local opinion leaders, audit and feedback, and reminder systems. DATA EXTRACTION: Details extracted from the studies included the study design; the unit of allocation (e.g., patient, provider, practice, hospital); the characteristics of the targeted health care professionals, educational interventions and patients (when appropriate); and the main outcome measure. DATA SYNTHESIS: The inclusion criteria were met by 102 trials. Areas of behaviour change included general patient management, preventive services, prescribing practices, treatment of specific conditions such as hypertension or diabetes, and diagnostic service or hospital utilization. Dissemination-only strategies, such as conferences or the mailing of unsolicited materials, demonstrated little or no changes in health professional behaviour or health outcome when used alone. More complex interventions, such as the use of outreach visits or local opinion leaders, ranged from ineffective to highly effective but were most often moderately effective (resulting in reductions of 20% to 50% in the incidence of inappropriate performance). CONCLUSION: There are no "magic bullets" for improving the quality of health care, but there are a wide range of interventions available that, if used appropriately, could lead to important improvements in professional practice and patient outcomes.
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OBJECTIVE: To review the literature relating to the effectiveness of education strategies designed to change physician performance and health care outcomes. DATA SOURCES: We searched MEDLINE, ERIC, NTIS, the Research and Development Resource Base in Continuing Medical Education, and other relevant data sources from 1975 to 1994, using continuing medical education (CME) and related terms as keywords. We manually searched journals and the bibliographies of other review articles and called on the opinions of recognized experts. STUDY SELECTION: We reviewed studies that met the following criteria: randomized controlled trials of education strategies or interventions that objectively assessed physician performance and/or health care outcomes. These intervention strategies included (alone and in combination) educational materials, formal CME activities, outreach visits such as academic detailing, opinion leaders, patient-mediated strategies, audit with feedback, and reminders. Studies were selected only if more than 50% of the subjects were either practicing physicians or medical residents. DATA EXTRACTION: We extracted the specialty of the physicians targeted by the interventions and the clinical domain and setting of the trial. We also determined the details of the educational intervention, the extent to which needs or barriers to change had been ascertained prior to the intervention, and the main outcome measure(s). DATA SYNTHESIS: We found 99 trials, containing 160 interventions, that met our criteria. Almost two thirds of the interventions (101 of 160) displayed an improvement in at least one major outcome measure: 70% demonstrated a change in physician performance, and 48% of interventions aimed at health care outcomes produced a positive change. Effective change strategies included reminders, patient-mediated interventions, outreach visits, opinion leaders, and multifaceted activities. Audit with feedback and educational materials were less effective, and formal CME conferences or activities, without enabling or practice-reinforcing strategies, had relatively little impact. CONCLUSION: Widely used CME delivery methods such as conferences have little direct impact on improving professional practice. More effective methods such as systematic practice-based interventions and outreach visits are seldom used by CME providers.
PURPOSE: To assess the extent to which relevant controlled clinical trials are cited and summarized in review articles, and to determine whether citation of relevant clinical trails is biased as to study results. DATA SOURCES: Articles were identified by searching MEDLINE and EMBASE databases. STUDY SELECTION: Review articles published between 1986 and 1988 on the clinical effectiveness of pneumococcal vaccine. DATA EXTRACTION: Proportion of relevant clinical trials cited and whether citation is biased by study results. DATA SYNTHESIS: The proportion of relevant primary studies cited per review article ranged from 0% to 36% (mean 9%). The number of trials cited per review ranged from zero to six (mean 1.2). In nine of 17 reviews, no clinical trials were cited. Study populations and outcome(s) were specified and results presented quantitatively for 0 to 27% of relevant trials per review (mean 6%). Unsupportive trials were almost twice as likely to be cited as supportive trials. CONCLUSIONS: Reporting of the results of relevant clinical trials in reviews of pneumococcal vaccine effectiveness is incomplete. Our findings suggest a need for greater scientific rigour in preparing, reviewing, and editing review articles.
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Preparing a review entails many judgments. The focus of the review must be decided. Studies that are relevant to the focus of the review must be identified, selected for inclusion and critically appraised. Information must be collected and synthesised from the relevant studies, and conclusions must be drawn. Checklists can help prevent important errors in this process. Reviewers, editors, content experts, and users of reviews all have a role to play in improving the quality of published reviews and promoting the appropriate use of reviews by decisionmakers. It is essential that both providers and users appraise the validity of review articles.
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OBJECTIVE: To identify the extent to which meta-analyses currently include unpublished data and whether editors, meta-analysts, and methodologists believe unpublished material should be included. DESIGN: This article describes two related studies: a literature review and a cross-sectional survey. SAMPLE SELECTION: For the literature review, we identified all articles indexed by the key word meta-analysis from January 1989 to February 1991 and determined whether unpublished material had been searched for, obtained, and included in the meta-analyses. For the cross-sectional survey, we surveyed authors of these meta-analyses, authors of articles addressing methodological issues in meta-analysis published during the same period, and editors of journals in which both types of articles were published. INTERVENTION: We asked the respondents about their attitudes concerning inclusion of unpublished data and publication of articles from which data had previously been included in a scientific overview. MAIN OUTCOME MEASURES: Inclusion of unpublished data and opinions about whether unpublished material should be included in overviews and whether prior inclusion of data in an overview should bear on publication. RESULTS: Of 150 meta-analyses, 46 (30.7%) included unpublished data in their primary analysis. Of authors surveyed, 85% responded. Of the meta-analysts and methodologists, 77.7% felt that unpublished material should definitely or probably be included in scientific overviews; this was true of 46.9% of the editors. A total of 86.4% of the meta-analysts and methodologists and 53.2% of the editors felt that inclusion of data in a prior overview should have no bearing on full publication of original research. CONCLUSION: While inclusion of unpublished data in scientific overviews remains controversial, most investigators directly involved in meta-analysis believe that unpublished data should not be systematically excluded. The most valid synthesis of available information will result when meta-analysts subject published and unpublished material to the same rigorous methodological evaluation and present results with and without unpublished sources of data.
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The objective of this study was to assess the sensibility of an asthma quality-of-life questionnaire (AQLQ); therefore, a structured survey of asthma patients seen in Hamilton, Ontario, emergency departments and physicians involved in asthma management was performed. Twenty-five consecutive patients who had completed the AQLQ questionnaire twice during a 7- to 10-day pilot study assessed sensibility using a 12-item questionnaire. The same number of practicing physicians from four centers in Ontario were sent the asthma AQLQ questionnaire and were asked to complete a 13-item sensibility form. All patients who were approached successfully completed the sensibility assessment; 80% (20 of 25) of the practicing physicians completed the assessment. Mean response scores were more than 5 of a possible 7 points in all questions for both groups. Patients had more mean responses greater than 6 (7 of 12) than did physicians (2 of 13). The AQLQ seems acceptable and sensible to both patients and physicians. A formal assessment of the sensibility of an outcome measurement can provide valuable information regarding it's use. Both research and clinical outcomes should be subjected to this form of evaluation.
Although the quality of health reporting has been criticized for being unscientific, evaluations of health care reporting have been limited by the lack of a reliable and credible measure of scientific quality. We developed an index of scientific quality (ISQ) for health-related news reports and tested its reliability and sensibility. Items were generated from a survey of the literature and experts in research methodology. Items that were unclear, confusing or discriminated poorly between articles of high and low scientific quality were revised or deleted in an iterative process wherein potential criteria were independently applied to samples of 5 to 15 articles by 6 raters. To test the reliability of the final criteria 60 articles were drawn from three sampling frames: newspapers, magazines, and professional journals. Articles were intentionally selected to obtain a wide range of quality and topics. Two categories of raters were used: research assistants and physicians with research training. All 6 raters assessed all 60 articles. The sensibility of the index was tested by a questionnaire with 13 items related to face validity and content validity as well as other aspects of sensibility. The questionnaire was completed by 20 researchers and 13 health and science writers. The final ISQ includes 7 items that address the extent to which a report allows readers to draw conclusions about the applicability, validity and practical importance of the information that is reported. Chance corrected agreement (kappa) among all 6 raters for overall scientific quality was 0.62 (SE 0.02). The index was found to be sensible with only one major problem, the need for judgment in making ratings. While some degree of subjectivity appears to be inevitable in rating the scientific quality of health reports, the ISQ is acceptable reliable and credible and should be useful for evaluating and improving the scientific quality of health reporting.
The object of this study was to assess the relationship between occupational dust exposure and chronic obstructive pulmonary disease (COPD). Studies were identified using MEDLINE (January 1966 to July 1991), SCISEARCH, manual review of reference lists, and personal contact with more than 30 international experts. Studies of COPD, lung function, emphysema, chronic bronchitis, or mortality in workers exposed to nonorganic dust were retrieved. Studies were included if dust exposure was measured quantitatively, and a quantitative relationship between dust exposure and one of the outcomes of interest was calculated while controlling at least for smoking and age. Methodological rigor was assessed, and data regarding the study populations, prognostic factors, and outcomes were extracted independently by two reviewers. Thirteen reports derived from four cohorts of workers met our inclusion criteria. Three of the cohorts were of coal miners and one was of gold miners. All of the studies found a statistically significant association between loss of lung function and cumulative respirable dust exposure. It was estimated that 80 (95% CI, 34 to 137) of 1,000 nonsmoking coal miners with a cumulative respirable dust exposure of 122.5 gh/m3 (considered equivalent to 35 years of work with a mean respirable dust level of 2 mg/m3) could be expected to develop a clinically important (> 20%) loss of FEV1 attributable to dust. Among 1,000 smoking miners the comparable estimate was 66 (95% CI, 49 to 84). The risk of a clinically important loss of lung function attributable to dust among nonsmoking gold miners was estimated to be three times as large as for coal miners at less than one fifth of the cumulative respirable dust exposure (21.3 gh/m3), the maximal exposure observed among the cohort of gold miners. We conclude that occupational dust is an important cause of COPD, and the risk appears to be greater for gold miners than for coal miners. One possible explanation of the greater risk among gold miners is the higher silica content in gold mine dust.
The objectives of this study were to assess the validity, reliability, and responsiveness of a disease-specific quality of life questionnaire (AQLQ) in asthma patients presenting for assessment and treatment in an emergency department (ED). Fifty-two patients 18 to 64 yrs of age were surveyed in three EDs. Admitted and discharged patients with stable and unstable asthma were included. Patients were interviewed prior to discharge from the ED. They completed a self-report asthma questionnaire, the self-administered Sickness Impact Profile (SIP) and AQLQ, a global assessment of asthma severity, a symptom questionnaire, and pulmonary function testing. Forty-three (83%) patients were available for follow-up at 7 to 10 days, and they completed a similar series of tests. Moderate correlations were found between total SIP and AQLQ measurements (r = 0.49; p < 0.001). Correlations were high between physical domain scores of the SIP and AQLQ symptoms (r = 0.58; p < 0.0001) and activity limitations (r = 0.50; p < 0.0001). Low correlations were found between pulmonary function results and AQLQ domains, except activity limitations (r = 0.44; p < 0.001). High correlations were found between symptoms or global assessments and AQLQ (r > 0.6; p < 0.0001). The instrument is highly responsive to small changes in patient status and outperforms pulmonary function tests and symptom scores in this setting. Test-retest reliability in patients who were stable was substantial (intraclass correlation coefficients > 0.9) on all aspects of the AQLQ.(ABSTRACT TRUNCATED AT 250 WORDS)
PURPOSE: To estimate the impact of chemotherapy on survival of patients with advanced non-small-cell lung cancer (NSCLC). METHODS: Randomized controlled trials (RCTs) published in the English-language medical literature between 1970 and 1991 were identified through MEDLINE and the reference lists of relevant articles. Six RCTs that accounted for 635 patients and compared first-line chemotherapy with supportive care in advanced NSCLC and reported survival up to at least 1 year were identified. Cumulative proportions of survival at 3, 6, 9, and 12 months for chemotherapy and control groups were derived from survival curves. RESULTS: Within each study, the effect of chemotherapy was estimated with a pooled relative risk (RR) across the four 3-month periods. An overall estimate of the RR of death at 1 year (RRM-H) was then calculated and a survival curve for chemotherapy-treated patients was constructed applying the pooled estimate of the RR (RRW) for each 3-month period. Overall, chemotherapy was associated with a 24% (95% confidence interval [CI], 13% to 34%) reduction in the probability of death when compared with supportive care. However, the effect of treatment appeared to decrease significantly after the first 6 months from therapy inception and the mean potential gain in survival, as compared with supportive care, was approximately 6 weeks (95% CI, 1 to 10). CONCLUSION: Chemotherapy is effective in the treatment of advanced NSCLC, but its impact on the length of survival is limited. Future RCTs should still include an untreated control group and should measure quality of life in addition to survival.
OBJECTIVE: To assess the impact of diverse continuing medical education (CME) interventions on physician performance and health care outcomes. DATA SOURCES: Using continuing medical education and related phrases, we performed regular searches of the indexed literature (MEDLINE, Social Science Index, the National Technical Information Service, and Educational Research Information Clearinghouse) from 1975 through 1991. In addition, for these years, we used manual searches, key informants, and requests to authors to locate other indexed articles and the nonindexed literature of adult and continuing professional education. STUDY SELECTION: From the resulting database we selected studies that met the following criteria: randomized controlled trials; educational programs, activities, or other interventions; studies that included 50% or more physicians; follow-up assessments of at least 75% of study subjects; and objective assessments of either physician performance or health care outcomes. DATA EXTRACTION: Studies were reviewed for data related to physician specialty and setting. Continuing medical education interventions were classified by their mode(s) of activity as being predisposing, enabling, or facilitating. Using the statistical tests supplied by the original investigators, physician performance outcomes and patient outcomes were classified as positive, negative, or inconclusive. DATA SYNTHESIS: We located 777 CME studies, of which 50 met all criteria. Thirty-two of these analyzed physician performance; seven evaluated patient outcomes; 11 examined both measures. The majority of the 43 studies of physician performance showed positive results in some important measures of resource utilization, counseling strategies, and preventive medicine. Of the 18 studies of health care outcomes, eight demonstrated positive changes in patients' health care outcomes. CONCLUSION: Broadly defined CME interventions using practice-enabling or reinforcing strategies consistently improve physician performance and, in some instances, health care outcomes.