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D G Altman

Publications and source records attributed to D G Altman.

At least 109 records · Page 6Linked to original sources
PubMed1996

Measurement error.

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Analysis of Variance↗
PubMed1996

Blinding and exclusions after allocation in randomised controlled trials: survey of published parallel group trials in obstetrics and gynaecology.

OBJECTIVE: To assess the methodological quality of approaches to blind ing and to handling of exclusions as reported in randomised trials from one medical specialty. DESIGN: Survey of published, parallel group randomised controlled trials. DATA SOURCES: A random sample of 110 reports in which allocation was described as randomised from 1990 and 1991 volumes of four journals of obstetrics and gynaecology. MAIN OUTCOME MEASURES: The adequacy of the descriptions of double blinding and exclusions after randomisation. RESULTS: Through 31 trials reported being double blind, about twice as many could have been. Of the 31 trials only eight (26%) provided information on the protection of the allocation schedule and only five (16%) provided some written assurance of successful implementation of double blinding. Of 38 trials in which the authors provided sufficient information for readers to infer that no exclusions after randomisation had occurred, six (16%) reported adequate allocation concealment and none stated that an intention to treat analysis had been performed. That compared with 14 (27%) and six (12%), respectively, for the 52 trials that reported exclusions. CONCLUSIONS: Investigators could have double blinded more often. When they did double blind, they reported poorly and rarely evaluated it. Paradoxically, trials that reported exclusions seemed generally of a higher methodological standard than those that had no apparent exclusions. Exclusions from analysis may have been made in some of the trials in which no exclusions were reported. Editors and readers of reports of randomised trials should understand that flawed reporting of exclusions may often provide a misleading impression of the quality of the trial.

Double-Blind Method↗
PubMed1996

Transforming data.

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Data Interpretation, Statistical↗
PubMed1996

Effect of integration of injury control information into a high school physics course.

STUDY OBJECTIVE: To investigate the effects on knowledge, attitudes, and self-reported behaviors of a 1-week course of injury control and crash safety information integrated within a high school physics curriculum. METHODS: Students in an intervention high school (n=129) were compared with students in a control high school (n=74) enrolled in a comparable physics curriculum. A standardized survey was administered before instruction (time T1), and at 2 weeks (T2) and 6 months (T3) after instruction was completed. The behaviors measured were self-reported use of seat belts, speeding, drinking and driving, and intention to use seat belts in the future. RESULTS: At T2, students in the intervention group reported attitudes that were less favorable toward risk-taking in regard to speeding and seat belt use than those of the control group. At T3, there was still a difference in attitudes toward speeding but not toward seat belt use. The intervention significantly altered the knowledge level of the course participants, and these changes persisted to T3. The strongest and most persistent change was that students in the intervention group reported increasing their use of seat belts when riding as a passenger. (Seat belt use as a driver was high for both groups.) The intervention group showed a significant increase in their 1-year intentions to use seat belts both as a driver and as a passenger. CONCLUSION: This study demonstrated that driver safety education can be successfully integrated into a mainstream high school science curriculum. Future studies measuring the effects of this curriculum on observed behaviors are needed.

Accidents, Traffic↗
PubMed1996

Testis conservation studies in germ cell cancer justified by improved primary chemotherapy response and reduced delay, 1978-1994.

OBJECTIVE: To investigate the need for the continued encouragement of early diagnosis of germ cell cancer of the testis, in view of the prevailing cure rate of 95%. PATIENTS AND METHODS: The study comprised a retrospective review of 453 unselected and previously untreated patients referred to one centre between 1978 and 1984, comparing the delay from first symptoms with the histological diagnosis. RESULTS: With a delay of < 30 days, 20% of patients had overt metastases at presentation and if the delay was > 4 months. 55% had metastases (chi-squared trend = 15.9, P < 0.001); 18% of Stage-1 patients under surveillance with a delay of < 30 days relapsed, compared with 38% of those with a delay of > 4 months. During the period 1978-1983, 16% of patients were seen after a delay of < 60 days, during the period 1984-1988 the proportion was 22% and during 1989-1994, 31% (chi-squared trend = 8.2, P < 0.004). There was a non-significant trend for a more prolonged delay in those aged < 21 years and > 40 years. Thirty-two patients had chemotherapy with the primary tumour in situ; at orchidectomy, 13 of 18 had no viable malignancy and four of five with viable malignancy also had drug-resistant metastases. Fourteen did not undergo orchidectomy; within a median follow-up of 9 years, one developed a second (histologically different) tumour after 12 years. The outcome of preliminary attempts to use neoadjuvant chemotherapy with or without partial orchidectomy for patients with tumours in a solitary testis is discussed. CONCLUSION: These findings clearly justify the continued encouragement of early diagnosis, possibly best performed as part of an extended educational programme of genital health at puberty. The long-term potential for testis conservation should be explored initially in tumours in a solitary testis.

Adult↗
PubMed1996

Tobacco farmers and diversification: opportunities and barriers.

OBJECTIVE: To assess the knowledge, attitudes, and behaviours of tobacco growers and allotment owners in the southeastern United States. DESIGN: Cross-sectional telephone survey. PARTICIPANTS: Tobacco growers (n = 529) and tobacco allotment owners (n = 417) were interviewed by telephone in March 1995. SETTING: Tobacco growing states in the southeastern US. MAIN OUTCOME MEASURES: Attitudes of tobacco growers and tobacco allotment owners towards, and experience with, diversification; and attitudes towards an increase in the federal excise tax on tobacco. RESULTS: Half of the respondents had done something to learn about on-farm alternatives to tobacco, had an interest in trying other on-farm ventures to supplement tobacco income, and found alternatives that were profitable. There was a strong, negative linear trend between age and being interested in or trying alternative enterprises. Structural and economic impediments to diversification were noted by respondents (especially younger respondents), but 73% supported an increase in the federal excise tax on tobacco if the money was used to help farmers overcome these barriers. CONCLUSIONS: These data suggest that farmers and health professionals have reason to establish dialogue around diversification and using excise tax increases to fund diversification and to promote health. Tobacco companies have been successful in mobilising farmers against tax increases, but efforts must be made to show farmers that tax increases can be beneficial both to their diversification efforts and to public health. The outcome of this dialogue may well affect the economic infrastructure of thousands of rural communities, the livelihood of tens of thousands of tobacco farmers and their families, and the health of millions of tobacco users.

Adult↗
PubMed1996

More informative abstracts revisited.

Following proposals in 1987 and 1988, several medical journals have provided more informative abstracts ("structured abstracts") for articles of clinical interest. Structured abstracts for original studies require authors to systematically disclose the objective, basic research design, clinical setting, participants, interventions (if any), main outcome measurements, results, and conclusions; and for literature reviews the objective, data sources, methods of study selection, data extraction and synthesis, and conclusions. More informative abstracts of this kind can facilitate peer review before publication, assist clinical readers to find articles that are both scientifically sound and applicable to their practices, and allow more precise computerized literature searches. We review the feasibility, acceptability, and dissemination of structured abstracts, reassess the underlying strategy, and describe modifications of the approach. This innovation can aid communication from scientists to clinicians, and other clinical journals are invited to join this effort.

Abstracting and Indexing↗