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Biomedical subjects

Kay Dickersin

Publications and source records attributed to Kay Dickersin.

At least 19 recordsLinked to original sources
PubMed2006

Development and validation of a computerized expert system for evaluation of automated visual fields from the Ischemic Optic Neuropathy Decompression Trial.

BACKGROUND: The objective of this report is to describe the methods used to develop and validate a computerized system to analyze Humphrey visual fields obtained from patients with non-arteritic anterior ischemic optic neuropathy (NAION) and enrolled in the Ischemic Optic Neuropathy Decompression Trial (IONDT). The IONDT was a multicenter study that included randomized and non-randomized patients with newly diagnosed NAION in the study eye. At baseline, randomized eyes had visual acuity of 20/64 or worse and non-randomized eyes had visual acuity of better than 20/64 or were associated with patients refusing randomization. Visual fields were measured before treatment using the Humphrey Field Analyzer with the 24-2 program, foveal threshold, and size III stimulus. METHODS: We used visual fields from 189 non-IONDT eyes with NAION to develop the computerized classification system. Six neuro-ophthalmologists ("expert panel") described definitions for visual field patterns defects using 19 visual fields representing a range of pattern defect types. The expert panel then used 120 visual fields, classified using these definitions, to refine the rules, generating revised definitions for 13 visual field pattern defects and 3 levels of severity. These definitions were incorporated into a rule-based computerized classification system run on Excel(R) software. The computerized classification system was used to categorize visual field defects for an additional 95 NAION visual fields, and the expert panel was asked to independently classify the new fields and subsequently whether they agreed with the computer classification. To account for test variability over time, we derived an adjustment factor from the pooled short term fluctuation. We examined change in defects with and without adjustment in visual fields of study participants who demonstrated a visual acuity decrease within 30 days of NAION onset (progressive NAION). RESULTS: Despite an agreed upon set of rules, there was not good agreement among the expert panel when their independent visual classifications were compared. A majority did concur with the computer classification for 91 of 95 visual fields. Remaining classification discrepancies could not be resolved without modifying existing definitions. Without using the adjustment factor, visual fields of 63.6% (14/22) patients with progressive NAION and no central defect, and all (7/7) patients with a paracentral defect, worsened within 30 days of NAION onset. After applying the adjustment factor, the visual fields of the same patients with no initial central defect and 5/7 of the patients with a paracentral defect were seen to worsen. CONCLUSION: The IONDT developed a rule-based computerized system that consistently defines pattern and severity of visual fields of NAION patients for use in a research setting.

Automation↗
PubMed2005

Selective exposure reporting and Medline indexing limited the search sensitivity for observational studies of the adverse effects of oral contraceptives.

OBJECTIVE: To explore development of possible approaches leading to a sensitive and precise Medline search to identify observational studies of the association between oral contraceptives and breast cancer, an adverse event. STUDY DESIGN AND SETTING: We compared the results of a series of Medline searches to a gold standard comprising 58 reports from a 1996 systematic review examining the relationship between oral contraceptives and the development of breast cancer. Sensitivity (the proportion of gold standard publications identified) and precision (the proportion of retrieved publications that were included in the gold standard) were calculated for each Medline search. RESULTS: We identified all 58 articles when the search was not limited by terms related to oral contraceptives, but precision was less than 1% (58 of 6,120). Indexing was problematic when oral contraceptives or hormones were not mentioned in the title or abstract (n = 8) or full text (n = 2). CONCLUSION: Search strategies identifying all relevant studies were possible but arguably impractical; additional research is needed to generalize our findings. Authors and editors should ensure that all interventions and outcomes examined are reported and indexers should make sure they are indexed. Central registration of observational studies and all variables they examined should be considered to assure identification of studies examining adverse events associated with health interventions.

Abstracting and Indexing↗
PubMed2005

Hormone replacement therapy, cancer, controversies, and women's health: historical, epidemiological, biological, clinical, and advocacy perspectives.

Routine acceptance of use of hormone replacement therapy (HRT) was shattered in 2002 when results of the largest HRT randomised clinical trial, the women's health initiative, indicated that long term use of oestrogen plus progestin HRT not only was associated with increased risk of cancer but, contrary to expectations, did not decrease, and may have increased, risk of cardiovascular disease. In June 2004 a group of historians, epidemiologists, biologists, clinicians, and women's health advocates met to discuss the scientific and social context of and response to these findings. It was found that understanding the evolving and contending knowledge on hormones and health requires: (1) considering its societal context, including the impact of the pharmaceutical industry, the biomedical emphasis on individualised risk and preventive medicine, and the gendering of hormones; and (2) asking why, for four decades, since the mid-1960s, were millions of women prescribed powerful pharmacological agents already demonstrated, three decades earlier, to be carcinogenic? Answering this question requires engaging with core issues of accountability, complexity, fear of mortality, and the conduct of socially responsible science.

Cardiovascular Diseases↗
PubMed2004

The Society for Clinical Trials supports United States legislation mandating trials registration. Position paper.

The official position of the Society for Clinical Trials is to support legislation in the United States and internationally that mandates registration of all controlled clinicals trials at or before enrollment of the first participant. The major trial sponsor would be responsible for ensuring contribution of trial information. The mechanism for registering trials would be through research ethics review boards, and registration would be required for ethics approval and before trial initiation. Standardized data and a unique identification number would be available for each registered trial.

Controlled Clinical Trials as Topic↗
PubMed2003

Registering clinical trials.

That it is not possible to find information about all initiated clinical trials is of international concern. This is a particular worry because scientists tend to publish their positive findings more often than their negative findings (publication bias). A comprehensive register of initiated clinical trials, with each trial assigned a unique identifier, would inform reviewers, physicians, and others (eg, consumers) about which trials had been started and directly address the problem of publication bias. Patients and their clinicians could also know which trials are open for enrollment, thus speeding medical advances. Individuals who participate in clinical trials typically provide consent in the belief that they are contributing to medical knowledge. But if the knowledge gained is never reported, the trust between patients and investigators and that between patients and research ethics review boards are both damaged. Ethical issues are of particular concern if industry is gaining financially from public involvement in trials, but refusing to reciprocate by making information from industry-sponsored trials generally available. All stakeholders-investigators, research organizations and institutions, journal editors, lawmakers, consumers, and others-must act now, together and in their own domains, to ensure comprehensive registration of clinical trials.

Clinical Trials as Topic↗
PubMed2003

Surgical quality assurance in the Ischemic Optic Neuropathy Decompression Trial (IONDT).

The purpose of this article is to report the methods and results of the surgical quality assurance program associated with the Ischemic Optic Neuropathy Decompression Trial (IONDT). A surgical quality assurance committee developed and implemented a quality assurance program for a randomized clinical trial requiring surgical intervention. A surgical technique questionnaire was administered at two times during the study course, and maintenance of surgeon certification required submission and approval of a masked videotape of an optic nerve sheath decompression surgery by each study surgeon. Surgical quality was assessed through completion of surgical report forms and standardized, masked review of operative notes. Rates of compliance and intra- and interreviewer agreement were assessed for each aspect of the program. Twenty-five of 32 surgeons (81%) successfully completed and maintained certification. Item agreement varied from 21-92% among reviewers of satisfactory videotapes and 22-89% on unsatisfactory videotapes. Intrarater agreement for videotape acceptability was 11 of 13 (85%), and for specific surgical steps, 147 of 182 (81%). Operative notes were submitted for 123 of 125 (98%) patients receiving surgery. Interrater agreement on individual items ranged from 73-100%. Classification of individual items was identical on first and second review for 1285 of 1344 (95.6%) items. Overall agreement for individual reviewers was 93.8-97.8%. We conclude that use of a small peer review committee, which developed and oversaw a quality assurance program, allowed for consistent certification and monitoring of surgical performance. This in turn increased the credibility of the IONDT results, which demonstrated no difference in outcome between operated and unoperated groups of patients.

Certification↗
PubMed2003

Surgical Treatments Outcomes Project for Dysfunctional Uterine Bleeding (STOP-DUB): design and methods.

The Surgical Treatments Outcomes Project for Dysfunctional Uterine Bleeding (STOP-DUB) was a multicenter, randomized clinical trial that assessed the efficacy and effectiveness of hysterectomy versus endometrial ablation (EA) for dysfunctional uterine bleeding (DUB) in women for whom medical management has not provided relief. Resource centers included a coordinating center, a chair's office, the American College of Obstetricians and Gynecologists, the Agency for Healthcare Research and Quality Project Office and 33 clinical centers in the United States and Canada. STOP-DUB enrolled: (1) eligible patients for whom medical treatment had not been successful and who were randomized to either hysterectomy or EA and (2) an observational cohort of patients who were "provisionally ineligible" or who were eligible but did not wish to be randomized. Enrollment began in October 1997 and ended in June 2001. The primary outcome addressed by the randomized trial was the impact of surgery on bleeding, pain, fatigue, and the major problem (symptom) that led the woman to seek treatment for her condition, measured 1 year following surgery. Additional outcomes included the impact of surgery at time points after 1 year; changes in quality of life, activity limitation, sexual functioning, and urinary incontinence; surgical complications; additional surgery; and resource utilization. The costs and the relative cost-effectiveness of the two surgeries were calculated. The main scientific objective for the observational study was to examine changes over time in terms of treatment selected, DUB-related symptoms, and quality of life.

Female↗
PubMed2003

Comparison of information obtained by operative note abstraction with that recorded on a standardized data collection form.

BACKGROUND: The Ischemic Optic Neuropathy Decompression Trial compared optic nerve decompression surgery with careful follow-up for treatment of patients with nonarteritic ischemic optic neuropathy. Surgeons submitted a standardized data collection form and operative notes for 123 patients randomized to and undergoing surgery. The purpose of this study was to see whether operative notes have sufficient and reliable data to avoid development of a surgery data collection form in future trials. METHODS: We abstracted data from Ischemic Optic Neuropathy Decompression Trial patient operative notes, calculated the proportion of completed responses, and compared abstracted responses with those originally recorded on corresponding case report forms. RESULTS: Variables used to identify persons, dates, or eye (left/right) were reported 100% of the time on operative notes and with excellent agreement with those recorded on the case report form (median agreement, 100%; range, 95% to 100%). Categoric variables, used to establish the characteristics of surgical steps, were also reported reliably on operative notes (median agreement, 84%; range, 0 to 100%). Open-ended variables tended to be reported more frequently on operative notes (exact agreement, 57% and 34%, respectively, for complications and postoperative medications). Quantitative variables were infrequently reported but correlated well with values reported on the data collection forms (Pearson correlation coefficients, 0.78, 0.79, 0.94, 0.96). For many variables, disagreements were minor and often were related to interpretation of the operative notes by the abstractor. CONCLUSION: In our trial, operative note abstraction adequately documented surgery date and surgeon and provided more complete information than the standardized report form with respect to complications but did not provide complete information for other variables.

Abstracting and Indexing↗
PubMed2002

Problems with indexing and citation of articles with group authorship.

CONTEXT: It is not known whether articles with group authorship (ie, with a research group name listed as the author) are difficult to identify or whether use of group authorship may lead to problems with citation. METHODS: To examine ways in which reports of controlled trials with group authorship are indexed and citations counted in bibliographic databases, we conducted a cross-sectional study in January 2000. We identified 47 controlled trials funded by the National Eye Institute and 285 associated articles. Between January and August 2000, we searched PubMed and Science Citation Index (SCI) and recorded the citation practices for these articles. Our main outcome measures were ways in which trial reports were listed in PubMed and SCI and number of citations to each report by type of authorship. RESULTS: Of the 285 published reports identified, 126 (44%) had group authorship, 109 (38%) had modified group authorship (listing individual names plus the name of the research group), and 50 (18%) had named authors only. In PubMed, no group authors were listed in the author field (per MEDLINE rules); in SCI, group-authored reports generally were incorrectly attributed (first name on investigator list [35.3%], first name on writing committee [25.5%], contact name [16.7%], anonymous [16.7%], and other [5.9%]). Using the SCI general search, we identified citations to 16.7% of group-authored reports, compared with citations to 96.9% of reports with modified group authorship and 93.9% of citations to reports with named authors only. Other systematic search methods found that more than 98% of group-authored reports actually had been cited and that group-authored reports were cited more than other reports. CONCLUSIONS: Indexing systems are not optimally adapted to group authorship. We recommend that indexing services change their practices to include group authors in the author field to help correct the problem.

Abstracting and Indexing↗
PubMed2002

Publication bias in editorial decision making.

CONTEXT: Studies with positive results are more likely to be published than studies with negative results (publication bias). One reason this occurs is that authors are less likely to submit manuscripts reporting negative results to journals. There is no evidence that publication bias occurs once manuscripts have been submitted to a medical journal. We assessed whether submitted manuscripts that report results of controlled trials are more likely to be published if they report positive results. METHODS: Prospective cohort study of manuscripts submitted to JAMA from February 1996 through August 1999. We classified results as positive if there was a statistically significant difference (P<.05) reported for the primary outcome. Study characteristics and indicators for quality were also appraised. We included manuscripts that reported prospective studies in which participants were assigned to an intervention or comparison group and statistical tests compared differences between groups. RESULTS: Among 745 manuscripts, 133 (17.9%) were published: 78 (20.4%) of 383 with positive results, 51 (15.0%) of 341 with negative results, and 4 (19.0%) of 21 with unclear results. The crude relative risk for publication of studies with positive results compared with negative results was 1.36 (95% confidence interval [CI], 0.99-1.88). After being adjusted simultaneously for study characteristics and quality indicators, the odds ratio for publishing studies with positive results was 1.30 (95% CI, 0.87-1.96). CONCLUSIONS: Among submitted manuscripts, we did not find a statistically significant difference in publication rates between those with positive vs negative results.

Biomedical Research↗
PubMed2002

Association between time interval to publication and statistical significance.

CONTEXT: Studies have shown that reports from clinical trials with statistically significant results tend to be submitted and published more rapidly than reports from studies with null or insignificant findings. METHODS: We wanted to determine whether manuscripts reporting positive results from controlled clinical trials are published more quickly than those reporting negative results. We tracked manuscripts from submission to JAMA until the publication decision. We classified results as positive if a statistically significant difference was reported for the primary outcome. Manuscripts were further classified according to indicators of methodologic quality and other study characteristics. We included manuscripts if they were submitted from February 1996 through August 1999, reported results of a prospective study in which participants were assigned to a treatment or comparison group, used statistical tests to compare differences between groups, and were accepted for publication. RESULTS: One hundred thirty-three manuscripts met our inclusion criteria, 78 (59%) reported positive results, 51 (38%) reported negative results. We were unable to classify the direction of results for 4 articles (3%). The time interval between submission and publication was not associated with positive results: median time between submission and publication was 7.8 months for reports with positive vs 7.6 months for reports with negative results (P =.44). Time to publication also was not associated with any marker of study quality or study characteristic. CONCLUSIONS: Among 133 published controlled trials, time to publication was not associated with statistical significance, methodologic quality, or other study characteristics.

Controlled Clinical Trials as Topic↗
PubMed2002

The fellow eye in NAION: report from the ischemic optic neuropathy decompression trial follow-up study.

PURPOSE: To examine the prevalence and incidence of second eye nonarteritic anterior ischemic optic neuropathy (NAION) and associated patient characteristics in patients enrolled in the Ischemic Optic Neuropathy Decompression Trial (IONDT) Follow-up Study. DESIGN: Randomized clinical trial with observational cohort. METHODS: Patients randomized to optic nerve sheath decompression surgery or careful follow-up had a diagnosis of acute unilateral NAION, visual acuity between 20/64 and light perception, and were aged 50 years or older. Eligible patients who declined randomization or whose visual acuity was better than 20/64 were not randomized but followed as part of an observational cohort. Follow-up examinations took place at 3, 6, 12, 18, and 24 months and annually thereafter. RESULTS: Four hundred eighteen patients were enrolled; 258 randomized and 160 observed. Previous NAION or other optic neuropathy was present in the fellow eye of 21.1% (88/418) of patients at baseline. Four patients developed optic neuropathy in the fellow eye at follow up that could not be conclusively diagnosed as NAION. New NAION in the fellow eye occurred in 14.7% (48/326) of patients at risk during a median follow up of 5.1 years. Randomized patients experienced a higher incidence (35/201; 17.4%) than nonrandomized patients (13/125; 10.4%). A history of diabetes and baseline visual acuity of 20/200 or worse in the study eye, but not age, sex, aspirin use, or smoking were significantly associated with new NAION in the fellow eye. Final fellow eye visual acuity was significantly worse in those patients with new fellow eye NAION whose baseline study eye visual acuity was 20/200 or worse. CONCLUSIONS: Follow-up data from the IONDT cohort provide evidence that the incidence of fellow eye NAION is lower than expected: new NAION was diagnosed in 14.7% of IONDT patients over approximately 5 years. Increased incidence is associated with poor baseline visual acuity in the study eye and diabetes, but not age, sex, smoking history, or aspirin use.

Acute Disease↗
PubMed2002

Quantitative impact of including consumers in the scientific review of breast cancer research proposals.

OBJECTIVE: To evaluate the impact of having breast cancer survivors with advocacy experience (consumers) participate as voting members of scientific review panels for proposals on breast cancer research. As major stakeholders, patients and other consumer advocates sought inclusion in all decision-making processes affecting funding of disease-targeted research. METHOD: Cross-sectional analysis of assigned proposal scores ranging from 5.0 (acceptable) to 1.0 (outstanding); before (prepanel) and after (postpanel) opinion questionnaires. Forty-six panels reviewed 2206 proposals for the Fiscal Year 1995 Department of Defense (DOD) Breast Cancer Research Program. Analyses were limited to the 42 panels scheduled to meet on site and the 2190 proposals scored by both participant groups. There were 85 consumers and 638 scientists. The main outcome measures were proposal merit scores (raw, overall, and participant-specific means) and opinions concerning perceived benefits and drawbacks of consumer involvement. RESULTS: In general, the voting patterns of consumers were similar to those of scientists. Final proposal scores were the same as those that would have been obtained without consumer voting for 76.2% of the proposals, more favorable for 15.2% of the proposals, and less favorable for 8.6% of the proposals. For all but 13 proposals, the difference was +/-0.1. Prepanel opinions regarding consumer involvement were generally positive. Prepanel and postpanel comparisons almost always showed that significantly greater proportions of participants had positive postpanel opinions than had negative postpanel opinions. Having consumers on review panels was reported to be beneficial (83.9% and 98.2% for scientists and consumers, respectively) and to not have drawbacks (74.7% and 87.3%, respectively). CONCLUSIONS: Our results support continued participation of consumers in our peer review process. The DOD program can serve as a model for other research programs considering consumer involvement.

Breast Neoplasms↗