Linga S. Dwarakanath

Planned vaginal delivery versus elective caesarean section: a study of 705 singleton term breech presentations

Objective To compare neonatal mortality and neonatal and maternal morbidity in planned vaginal delivery versus elective caesarean section for breech presentation at term. To identify factors associated with the risk of caesarean section during labour.

Logistic regression models in obstetrics and gynecology literature.

OBJECTIVE To evaluate the reporting of multivariable logistic regression analyses and assess variations in quality over time in the obstetrics and gynecology literature. METHODS Methodologic criteria for reporting logistic regression analyses were developed to identify problems affecting accuracy, precision, and interpretation of this approach to multivariable statistical analysis. These criteria were applied to 193 articles that reported multivariable logistic regression in the issues of four generic obstetrics and gynecology journals in 1985, 1990, and 1995. Rates of compliance with the methodologic criteria and their time trends were analyzed. RESULTS The proportion of articles using logistic regression analysis increased over time: 1.7% in 1985, 2.8% in 1990, and 6.5% in 1995 (P < .001 for trend). Violations and omissions of methodologic criteria for reporting logistic models were common. The research question, in terms of dependent and independent variables, was not clearly reported in 32.1%. The process of variable selection was inadequately described in 51.8% of the articles. Among articles with ranked independent variables, 85.1% did not report assessment of conformity to linear gradient. Tests for goodness of fit were not given in 93.2% of articles. The contribution of the independent variables could not be evaluated in 36.2% of the articles because of a lack of coding of the variables. Interactions between variables were not assessed in 86.4% of articles. Analysis of variations in the quality of logistic regression analyses over time showed no increase in reporting of the criteria concerning variable selection and goodness of fit. However, the proportion of articles reporting one quality criterion concerning interpretation of the substantive significance of independent variables showed a trend toward improvement: 42.3% in 1985, 73.6% in 1990, and 75.4% in 1995 (P = .004 for trend). CONCLUSION The reporting of multivariable logistic regression models in the obstetrics and gynecology literature is poor, and the time trends of improvement in quality of reporting are not particularly encouraging.

A controlled analysis of authorship trends over two decades

OBJECTIVE The purpose was to assess authorship trends over time by taking account of publication type and controlling for number of investigating centers and funding status in a multivariable analysis. STUDY DESIGN A database of 403 randomized studies and 193 controlled observational studies was assembled by means of a combination of electronic and hand search of 4 generic obstetrics and gynecology journals for the years 1975, 1980, 1985, 1990, and 1995. A multivariable logistic regression model was built for evaluating the effect of time on authorship with multiauthored articles as the binary outcome variable (articles were classified as either those with <6 authors or those with >/=6). The analysis was performed separately for the 2 types of publications, and it was adjusted for the confounding effects of number of centers, funding status, and journal of publication. The beta coefficient (and its exponent) associated with the time term in the logistic model provided a measure of the trend in publication of multiauthored articles. RESULTS In randomized studies the odds of publishing a multiauthored article, given the number of centers, funding status, and journal, were increased on average by 6% with every 5-year increment in time (odds ratio, 1.06; 95% confidence interval, 1.02-1. 10; P =.007). Similarly, in controlled observational studies, there was a 10% increase in the odds of publishing multiauthored articles (odds ratio, 1.10; 95% confidence interval, 1.01-1.20; P =.03). CONCLUSION There is an inflationary trend in authorship that is not explained solely by the increased collaboration between centers and funding for research.

Critical appraisal workshops to promote evidence-based healthcare.

We evaluated the effect of literature appraisal workshops on participants views, attitudes and knowledge about evidence-based medicine in the West Midlands region in 1998. The performance of 55 practitioners was evaluated, before and after attending the workshop. After attending the workshop, participants paid more attention to the study design (81% vs. 98%, P=0.02), they did not find research evidence confusing (35% vs. 52%, P=0.05), and they felt more confident in assessing research evidence (26% vs. 59%, P=0.0001). Their mean knowledge scores improved from 47.3 (SD12.2) to 57.9 (SD 9.0) ( P=0.0001). Our critical appraisal skills workshops improved attitudes and knowledge needed for the provision of evidence-supported healthcare. Such workshops should be incorporated in postgraduate obstetrics and gynaecology training programmes.We evaluated the effect of literature appraisal workshops on participants views, attitudes and knowledge about evidencebased medicine in the West Midlands region in 1998. The performance of 55 practitioners was evaluated, before and after attending the workshop. After attending the workshop, participants paid more attention to the study design (81% vs. 98%, P=0.02), they did not find research evidence confusing (35% vs. 52%, P=0.05), and they felt more confident in assessing research evidence (26% vs. 59%, P=0.0001). Their mean knowledge scores improved from 47.3 (SD12.2) to 57.9 (SD 9.0) ( P=0.0001). Our critical appraisal skills workshops improved attitudes and knowledge needed for the provision of evidence-supported healthcare. Such workshops should be incorporated in postgraduate obstetrics and gynaecology training programmes.

Simplifying laparoscopic surgery for ectopic pregnancies

Sir, Dr Pittrof has raised several important questions. The first about the appropriateness of the control group is based on an apparent misreading of the article. The CPD cases referred to in the article were part of a related study which shared the control group used in this PPH study. The control group for both case groups consisted of the same 299 women with normal unassisted vaginal deliveries. The 28% of haemorrhage cases with a labour of more than 10 hours but less than 18 hours (as this was the cut-off for a normal labour) were unlikely to have represented any CPD cases in the PPH group. Thus, there were no CPD cases in either the control group or the PPH case group. As for the rate of PPH in this group, it was indeed low. There were 26 212 women delivering in Greater Harare during the 8-month study period, of which 22 360 (85%) delivered in the public system covered by the study. As stated in the article, the 151 PPH cases consisted of all cases meeting the rather strict haemorrhage eligibility criteria (resident of Harare, normal labour, no anaesthesia or other intervention). Because of the excellent public system of care and of record keeping in Harare, one can have a high degree of confidence that few if any cases of PPH were missed. Since there are no data available on the denominator (i.e., the percentage of those 22 360 deliveries that were residents and were normal and unassisted), it is not possible to calculate the true PPH rate (or to compare it with PPH rates based on populations which included complicated and surgical deliveries). There are several possible explanations for the apparently lower PPH rate. First and foremost, all women routinely receive a dose of syntometrine or ergometrine at the time of delivery. In addition, management of labour by midwives (the primary caregiver) is conservative and may, therefore, reduce the risks of haemorrhage. Finally, women in Harare (and Zimbabwe generally) enjoy a somewhat better state of health than those in many developing countries and may have a lower risk of PPH. Better data on PPH rates are clearly needed, especially data that separate haemorrhage due to labour complications and medical interventions from that which occurs without warning after a seemingly normal delivery. Better methods for quantifying blood loss and recognising haemorrhage will be needed before community-based data from rural populations will be obtainable. Vivien Tsu 2532 11th Avenue West Seattle, Washington, USA Postpartum haemorrhage in Zimbabwe: a risk factor analysis