The problem with epidemiological associations is the wide variety of things which may be driving them.  For example, a new study  reports an association between hospital geographic location and the variation in primary cesarean delivery rates in the United States. This phenomena is not limited to the United States, a study published in the European Journal of Public Health reports evidence of local drivers of cesarean rates. How much do all these factors matter?  In the cesarean study, almost 40% of the variation in adjusted relative risk for primary cesarean — in plain terms, these factors mattered quite a bit. The question is, what are these local drivers?Read More →

No one really believes the Friedman Curve represents timing of cervical dilation anymore.   Modern researchers have used more sophisticated techniques to identify problems with the Friedman Curve, generally about the slope of the line which represents the speed or progress of dilation. What remains from the Friedman Curve is the idea that labor has a line that can represent the normal process of dilation. This line becomes the basis of judgement of normality of labor. In some places the labor progress is charted in a partograph to allow visual comparison of the progress to the line. Decisions to intervene are made based on deviation fromRead More →

When your job is basically to write, you have to let other people read what you write. This is the worst, and best, part of writing.  This week I had to submit my draft dissertation proposal to two professors and the entire grant mock review committee. I have feedback from the two professors, and I have to admit I’m really happy with the comments.  I think this speaks to the benefit of working through to a third version with three members of my committee before sharing the draft. Those of you not in the academic community may wonder why so many eyes are helpful forRead More →

A study published in the June edition of Acta obstetricia et gynecologica Scandinavica explored fear of childbirth through maternal surveys.  While the study question was about the effect of counseling for fear of childbirth, several interesting things are revealed in the descriptive statistics (the part of the study where the researchers tell you about the individuals in the study). The authors report this counseling was generally from midwives either with or without specialized training in counseling, or from an obstetrician, and the counseling is never really described as an intervention.  For that reason we won’t dwell too much on the effects of the counseling. Out of 936 womenRead More →

Here is an opportunity for you to participate in research that helps us understand what it is like to become a mother.  Researchers at the University of Michigan are investigating the pregnancy-related experiences that are unique to sexual minorities to help minimize the effect of these stressors on prenatal and postnatal outcomes. If you are a lesbian couple, aged 18-45 and expecting your first child, they want to talk to you.  Here is a flier that provides general information: Flyer (pdf) And a few more specifics if it helps you decide: For this study, we are recruiting lesbian couples ages 18 to 45 who are expecting their first child. IfRead More →

I’ve spent the last five years learning how to interpret research, I know it isn’t easy.  I didn’t always know this.  I used to think I could read the conclusions of a paper, check out a few things and either incorporate it or ignore it.  The problem was, just like all humans, my trust in a paper was more related to how closely it resembled what I already believed than anything within the design of the study. Now when I read a paper I go through a long process of making decisions; What exactly is the research question? What theory does this study build from?Read More →

I wanted to take a moment to thank you for spending the summer learning how to read the statistics in research with me.  I hope you found the series helpful, and maybe it inspired you to read more research.  If so, I have a few resources you might like to know about. The Birthing Naturally Twitter Feed posts a different study about pregnancy, childbirth and the post-postpartum every day.  Follow the feed for daily links to relevant abstracts. The Cochrane Collaboration has a Pregnancy and Childbirth Group.  Their page provides easy access to the research summaries from their systematic reviews. When you search in PubMed,Read More →

You may have been wondering why I had not discussed qualitative research in this series.  The un-glamorous answer is that while qualitative research helps to inform practice, it doesn’t actually use statistics as we think about them. Statistics lives in the world of numbers, and is used in research that is called quantitative — basically because it counts things.  But qualitative research isn’t about counting things.  It is about openly exploring an area to gain perspective rather than statistical significance. So while quantitative studies as people to complete surveys and provide blood samples for testing, qualitative studies ask people open ended questions or observe howRead More →

Last time we talked about the unique contributions of a systematic review.  Today we will talk about how meta-analysis informs our practice. Remember, these are both techniques that synthesize existing data. This means just like a systematic review, a meta-analysis must be performed with rigor.  A very specific question should be asked, and inclusion and exclusion criteria defined before collecting available studies.  Multiple databases must be searched, and counts of excluded studies and the reasons should be kept. Where a meta-analysis differs is in the actual analysis. Remember when we talked about the importance of sample size to obtaining accurate estimates? Meta-analysis uses statistical techniques to poolRead More →

For today’s post, you might want to open a second window at the Cochrane Collaboration Website so you can scroll through what is available while we talk. One thing I have been trying to communicate (over and over and over) is that each study is only one small piece of the puzzle researchers use to help figure out what is going on.  Today we are going to talk about one tool researchers use to synthesize the available data, the Systematic Review.Read More →