Primer on Statistics for Interventional

CardiologistsGiuseppe Sangiorgi, MD

Pierfrancesco Agostoni, MDGiuseppe Biondi-Zoccai, MD

What you will learn• Introduction• Basics• Descriptive statistics• Probability distributions• Inferential statistics• Finding differences in mean between two groups• Finding differences in mean between more than 2 groups• Linear regression and correlation for bivariate analysis • Analysis of categorical data (contingency tables)• Analysis of time-to-event data (survival analysis)• Advanced statistics at a glance• Conclusions and take home messages

There are only 10 attitudes towards binary numbers:

There are only 10 attitudes towards biostatistics:

There are only 10 attitudes towards binary numbers:

either you understand them or not

There are only 10 attitudes towards biostatistics:

either you practice it or you ignore it

Statistics is just like PCI

• Keep on criss-crossing between published papers, your own data, your own analyses and chit-chat with colleagues or (even would-be) expert: it helps a lot on the long-term

• Nobody was accomplished and quick the first time he took a guiding (or even diagnostic!) catheter in hand: now look at yourself and what you have done in interventional cardiology!

• Keep focused and work on what you like and what you need

Helpful websites• http://faculty.vassar.edu/lowry/anova1u.html: I use it routinely to do ANOVA

online• http://home.clara.net/sisa/index.htm: thorough but easy going, focused on

analyses and sample size computations• http://members.aol.com/johnp71/javastat.html: with many useful links for

statistical analyses and sample size computations• http://www.cdc.gov: provides Epi-Info and StatCalc freewares• http://www.metcardio.org: for those with a specific interest in meta-analyses• http://www.quantitativeskills.com/sisa/statistics/twoby2.htm: I use it

routinely to do chi-square and Fisher exact tests online• http://www.randomization.com: ideal to create your own randomization

lists• http://www.resample.com/content/software/excel/download.shtml:

provides tools for home-made resampling analyses• http://www.virtualstatistician.com/link-63.html: very comprehensive,

sometimes too focused on methods and dry

SoftwaresFreewares:•Epi-Info•R•RevMan

Proprietary softwares:•BMDP•LogXact•Minitab•S-Plus•SAS: most comprehensive and complex•SPSS: user-friendly but rather rigid (nonetheless our 1st choice)•STATA: high-quality graphs, top-notch for meta-analysis•Statistica•StatsDirect•StatXact

Thank you for your attention

For any correspondence: gbiondizoccai@gmail.com

For further slides on these topics feel free to visit the metcardio.org website:http://www.metcardio.org/slides.html