Introduction to Biostatistics - bebac.at

1 1 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeHelmut Sch tzBEBACH elmut Sch tzBEBACW ikimediaWikimediaCommons Commons 2007 2007 Sujit KumarSujit Kumar Creative Commons AttributionCreative Commons UnportedUnportedIntroduction to BiostatisticsPart I: Basic ConceptsIntroduction to Introduction to BiostatisticsBiostatisticsPart I: Part I: Basic Basic ConceptsConcepts2 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeBiometryBiometry, , BiometricsBiometrics,,and and BiostatisticsBiostatistics Introduced in 1947 by Fisheras Biometry and later Biometrics Biometry, the active pursuit of biologicalknowledge by quantitative methods.

2 The International Biometric Society The terms Biometrics and Biometry have been used since early in the 20thcentury to refer to the field of development of statistical and mathematical methods applicable to data analysis problems in the biological sciences. Recently, the term Biometrics has also been used to refer to the emerging field of technology devoted to identification of individuals [..] Biostatistics was introduced as a new 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeBiometryBiometry, , BiometricsBiometrics,,and and BiostatisticsBiostatisticsStatisticsStat istics.

3 A subject which most A subject which most statisticians find difficult but in which nearly statisticians find difficult but in which nearly all physicians are physicians are . One who has neither theOne who has neither theintellect for mathematicsintellect for mathematicsnor the commitment for nor the commitment for medicine but likes to dabble in but likes to dabble in Medical sstatisticiantatistician.. One who will not accept that One who will not accept that Columbus discovered discovered he said because he said he was looking for India in the trial was looking for India in the trial Stephen SennSenn4 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeTerminologyTerminologyIIhigh biaslow biaslow variancehigh variancebias5 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3.))

4 Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeTerminologyTerminologyIIII datacontinuousdiscretenominal scaleordinal scaleinterval scaleratio scaledistictnessdistictness +rank orderdistictness +rank order +intervaldistictness +rank order +interval +ratioincreasing information6 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeDataDataII Nominal scale (aka categorial) Sex, ethnicity.

5 Statistics:mode, test Transformations: equality Ordinal scale School grades, disease states,.. Statistics:median, percentile, sign test,Wilcoxon test Transformations: monotonic increasing order7 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeDataDataIIII Interval scale Calendar dates, temperature in C, IQ,.. Statistics: mean, variance (standarddeviation), correlation, regression,ANOVA Transformations: linear Ratio scale Measures with true zero point, temperature in K.

6 Statistics:all of the above, geometric and harmonic mean, coefficient ofvariation Transformations: multiplicative, logarithm8 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeExamples fromExamples fromPKPK Ordinal scale tmax, tlag Statistics:median, percentile, sign test,Wilcoxon test Transformations: monotonic increasing order Ratio scale AUC, Cmax, z,.. Statistics:mean, variance (standarddeviation), correlation, regression,ANOVA, geometric and harmonicmean, coefficient of variation Transformations: multiplicative, logarithm9 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeBell Bell curvecurve and and beyondbeyond Abraham de Moivre (1667 1754), Pierre-Simon Laplace (1749 1827)Central limit theorem1733, 1812 Frank Wilcoxon (1892 1965)Nonparametric tests1945 Carl F.

7 Gau (1777 1855)Normal distribution1795 William S. Gosset, aka Student (1876 1937)t-distribution1908 Ronald A. Fisher (1890 1962)Analysis of variance191810 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma Edgenormal distr.: mean = 100 CV = 30 %n = distr.: mean = 100 CV = 30 %n = distr.: mean = 100 CV = 30 %n = distr.: mean = 100 CV = 30 %n = DistributionsStatistical Distributions11 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeStatistical DistributionsStatistical Distributionslognormal distr.

8 : mean = 100 CV = 30 %n = distr.: mean = 100 CV = 30 %n = distr.: mean = 100 CV = 30 %n = distr.: mean = 100 CV = 30 %n = 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeStatistical DistributionsStatistical Distributions Normal Distribution Defined by location (aka central tendency)and dispersion Population Location: population mean Dispersion:population variance Sample Location: sample mean Dispersion:sample variance Probability = 1 within- and + x2s2 2121( )2xf xe =2121( )2txF xedt = 13 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeStatistical DistributionsStatistical Distributions Lognormal Distribution Defined by location and dispersion Population Location: population mean Dispersion:population variance Sample Location: sample mean Dispersion.

9 Sample variance Probability = 1 within0and + x2s2 ()22ln210( )200xexf xxx >= ()22ln2011( )2txF xedtt = 14 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeStatistical DistributionsStatistical Distributionsnormal distr.: mean = 100 sd = 20 CV = 20 %n = distr.: mean = 120 sd = 24 CV = 20 %n = distr.: mean = 110 sd = CV = %n = distr.: mean = 100 sd = 20 CV = 20 %n = distr.: mean = 100 sd = 30 CV = 30 %n = distr.

10 : mean = 100 sd = CV = %n = 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeStatistical DistributionsStatistical Distributionspopulation: mean = 100 sd = CV = %N = 1e+ 1: mean = 101 sd = CV = %n = 2: mean = sd = CV = %n = 3: mean = sd = CV = %n = 4: mean = sd = CV = %n = 5: mean = sd = CV = %n = 57 Introduction to Introduction to BiostatisticsBiostatistics(1/3: Basic (1/3: Basic ConceptsConcepts))BiostatisticsBiostatis tics: Basic concepts & applicable principles for various designs: Basic concepts & applicable principles for various designsin in bioequivalencebioequivalencestudiesstudi esand data analysisand data analysis| | MumbaiMumbai, , 29 29 3030 January January 20112011 Pharma EdgeStatistical DistributionsStatistical Distributionspopulation: mean = 100 sd = CV = %N = 1