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Biomedical subjects

Steven N Goodman

Publications and source records attributed to Steven N Goodman.

25 records · Page 2Linked to original sources
PubMed2002

How statistical expertise is used in medical research.

CONTEXT: Investigation of the nature and frequency of statistician involvement in medical research and its relation to the final editorial decision. METHODS: Authors of original research articles who submitted to BMJ and Annals of Internal Medicine from May through August 2001 were sent a short questionnaire at the time of manuscript submission. Authors were asked if they received assistance from a person with statistical expertise, the nature of any such contribution, and reasons why, if no statistical input was received. RESULTS: The response rate was 75% (704/943); methodological input was reported for 514 (73%) of these papers. In 435 papers (85%), such input was provided by biostatisticians or epidemiologists and, if deemed significant, was typically associated with authorship. A total of 33 of 122 methodologists (27%) whose main contribution started at the analysis stage received neither acknowledgment nor authorship. Research without methodological assistance was more likely to be rejected without review (71% vs 57%; chi(2) = 10.6; P =.001) and possibly less likely to be accepted for publication (7% vs 11%; chi(2) = 2.37; P =.12). CONCLUSIONS: Statistical input to medical research is widely recommended but inconsistently obtained. Individuals providing such expertise are often not involved until the analysis of data and many go unrecognized by either authorship or acknowledgment.

Authorship↗
PubMed2002

Counting alleles to predict recurrence of early-stage colorectal cancers.

BACKGROUND: Chromosome imbalances occur in many cancers and represent important biological properties of tumours. However, measurements of such imbalances are difficult. We used a new, quantitative approach to investigate the prognostic value of chromosome imbalances in early-stage colorectal cancers. METHODS: We studied 180 patients with no evidence of lymph-node or distant metastases at the time of surgery. DNA from paraffin-embedded tumours was tested for imbalances of chromosome 8p and 18q by digital SNP (single-nucleotide polymorphism)-a technique in which each allele in a sample is directly counted. Surviving patients had median follow-up of 68 months, and disease recurrence was used as the clinical endpoint. FINDINGS: Tumours were divided into three groups: "L" tumours (n=93) had allelic imbalances of chromosomes 8p and 18q, "L/R" tumours (n=60) had allelic imbalances of either chromosome 8p or 18q but not both, and "R" tumours (n=27) retained allelic balance for both chromosomes. 5-year disease-free survival was 100% (95% CI 80-100) for patients with R tumours, 74% (61-87) for patients with L/R tumours, and 58% (47-69) for those with L tumours. These differences were significant (p<0.0001) and were independent of other variables--eg, Duke's stage A tumours of class L were much more likely to recur than Duke's stage B tumours of class R (p=0.002). INTERPRETATION: In patients without metastasis, allelic imbalance is a better predictor of prognosis than histopathological stage.

Aged↗
PubMed2002

Hypermethylation of the DNA repair gene O(6)-methylguanine DNA methyltransferase and survival of patients with diffuse large B-cell lymphoma.

BACKGROUND: The gene encoding the DNA repair enzyme O(6)-methylguanine DNA methyltransferase (MGMT) is transcriptionally silenced by promoter hypermethylation in several human cancers, including diffuse large B-cell lymphoma (B-DLCL). MGMT promoter hypermethylation is a favorable prognostic marker in patients with brain tumors treated with alkylating agents. METHODS: In a retrospective cohort study, we used methylation-specific polymerase chain reaction to analyze the MGMT promoter methylation status in tumor DNA of B-DLCL patients receiving cyclophosphamide as part of multidrug regimens. Molecular data were compared with patient response with the use of Student's t test. Disease-free survival and overall survival were estimated by the Kaplan-Meier method and compared with the use of the log-rank test. Multivariable survival analyses were performed with the Cox proportional hazards model. All statistical tests were two-sided. RESULTS: Thirty (36%) of 84 B-DLCL patients showed MGMT promoter hypermethylation in their lymphomas. The presence of MGMT methylation was associated with a statistically significant increase in overall survival (hazard ratio for time to death for nonmethylation versus methylation = 2.8; 95% confidence interval (CI) = 1.2 to 7.5; P =.01) and progression-free survival (hazard ratio for time to progression for nonmethylation versus methylation = 2.6; 95% CI = 1.3 to 5.8; P =.02). MGMT promoter hypermethylation was both independent of and stronger than established prognostic factors, such as age, disease stage, serum lactic dehydrogenase level, and performance status. CONCLUSION: MGMT promoter hypermethylation appears to be a useful marker for predicting survival in patients with B-DLCL treated with multidrug regimens including cyclophosphamide.

Antineoplastic Agents, Alkylating↗
PubMed2002

Acne therapy: a methodologic review.

BACKGROUND: Acne is a very common problem with significant physical and psychological morbidity. The evidence basis for its treatment had not been systematically reviewed. Therefore, we performed an evidence review to provide researchers a basis for further studies, and to provide clinicians the background needed to interpret current and future clinical studies. OBJECTIVE: We summarize the methodologic state of the acne literature in patients with acne who do not have complicating co-morbidities. METHODS: This was an expert-advised literature synthesis. We used a structured literature search for English-language controlled trials in Cochrane CENTRAL, MEDLINE, OLDMEDLINE, HSTAT, CINAHL, and PsychInfo. Results underwent a structured data abstraction process, with review by at least 2 reviewers. RESULTS: Out of 1588 unique articles, 250 articles (274 controlled trials) over the past 50 years were reviewed: 57 (21%) trials had at least one major weakness and no strengths; 125 (47%) trials had at least one major strength and at least one major weakness; 48 (18%) trials had at least one major strength, and no major weaknesses. The remaining 16 (6%) were of intermediate quality or did not provide enough information to make a determination. One fourth of studies did not report patient age; one fourth did not report on patient gender. Only 8% mentioned patient race; only 2% mentioned skin type; 0.4% mentioned diet; none scored sexual maturity or insurance status. There were 1237 outcomes. There were more than 25 methods of assessing acne severity and more than 19 methods for counting lesions. There were only two trials that formally assessed psychological outcomes. More than 140 treatments were tested in 251 comparisons. CONCLUSION: Ranging over 50 years of research, the acne literature evidences great heterogeneity at all levels: patient characteristics, acne severity, outcome assessments, treatments, and comparisons. A list of methodologic recommendations is provided.

Acne Vulgaris↗
PubMedDate not supplied

Nonsteroidal anti-inflammatory drugs for the prevention of Alzheimer's disease: a systematic review.

OBJECTIVE: Alzheimer's disease, the most prevalent dementia, is a prominent source of chronic illness in the elderly. Laboratory evidence suggests that nonsteroidal anti-inflammatory drugs (NSAIDs) might prevent the onset of Alzheimer's disease. Since the early 1990s numerous observational epidemiological studies have also investigated this possibility. The purpose of this meta-analysis is to summarize and evaluate available evidence regarding exposure to nonaspirin NSAIDs and risk of Alzheimer's disease using meta-analyses of published studies. METHODS: A systematic search was conducted using Medline, Biological Abstracts, and the Cochrane Library for publications 1960 onwards. All cross-sectional, retrospective, or prospective observational studies of Alzheimer's disease in relation to NSAID exposure were included in the analysis. At least 2 of 4 independent reviewers characterized each study by source of data and design, including method of classifying exposure and outcome, and evaluated the studies for eligibility. Discrepancies were resolved by consensus of all 4 reviewers. RESULTS: Of 38 publications, 11 met the qualitative criteria for inclusion in the meta-analysis. For the 3 case-control and 4 cross-sectional studies, the combined risk estimate for development of Alzheimer's disease was 0.51 (95% Cl=0.40-0.66) for NSAID exposure. In the prospective studies, the estimate was 0.74 (95% Cl=0.62-0.89) for 4 studies reporting lifetime NSAID exposure and it was 0.42 (95% Cl=0.26-0.66) for the 3 studies reporting a duration of use of 2 or more years. CONCLUSIONS: Based on analysis of prospective and nonprospective studies, NSAID exposure was associated with decreased risk of Alzheimer's disease. An issue that requires further exploration in future trials or observational studies is the temporal relationship between NSAID exposure and protection against Alzheimer's disease.

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