tailieunhanh - How to Display Data- P8

How to Display Data- P8:The best method to convey a message from a piece of research in health is via a fi gure. The best advice that a statistician can give a researcher is to fi rst plot the data. Despite this, conventional statistics textbooks give only brief details on how to draw fi gures and display data. | Displaying univariate categorical data 27 Maternal age years Figure Stacked bar chart showing the relative frequency of feeding methods between the different age is that it is difficulttocompare intermediate categorie s such as themixe d feeding categodrSboChbraasa eonndamilk in Figure . In general clustered bar charts are preferable. Summaryofthe main pointswhen dis la incj categorical data C rtaim. p b ed Sphyea S ng . . Bar charts are preferable to pie charts. Use pie chMtoMilyfOTdis png one set of proportions. Use clusteredCarchartstodisplaytwo or mosesetsof proportions. Always include brr Ootal ru iiirr oS tubjartti Oor cluster or stacked bar charts always indodtthenumbnr ineach groan Never use tyoostdimensionrSbrr charSsorpiecnarS s they oso difficultto read and c an Ce misUeading. Different shtdrs of Che semssolbos sreaestUordistrnsuishing between different dittingnisUbstwren differrne groups shonldbrusedwrtheaueion. Discrete os cobni Uctocsmbebtsblayrensmgdnrcharts. 28 How to Display Data References 1 O Cathain A Wallers S NichollJP Thomas KJ Kirkham M. Use of evidence based leaflets to promote infomred choice in maternity care randomised controlled trial in Medical Journal 2002 324 643-6. 2 Ehrenberg in dataredwtien. Chichesterrjohn Wiley Mn 2000. Chapter 4 Displaying quantitative data This chapter will describe the basic graphs available for displaying quantitative data. As described in Chapter 1 quantitative data can be either counted or continuous. Count data are also known as discrete data and as the name implies occurwhenthe data can becounted such asthe numberof children in a family ortCd numberofvicitstoaGn aru data that can be msasured andinprindplu titencantihfc nnyvaCueonth e scale on whichtCnyssameucnred tlihnans emSCedonty Cs Stet psctsrionof the scale ofmerroremebt und roancbter indudeheighttWrirni andbldod pressure.