https://communities.sas.com/t5/Statistical-Procedures/Proc-Mixed-and-missing-data-with-crossover/m-p/315301#M16615 <P>Provided the data are "missing at random", then the estimates from PROC MIXED are valid. &nbsp;However, if the missing data are not at random (say due to cumulative toxicity and subject dropout), then you should consider other options.</P> <P>&nbsp;</P> <P>Steve Denham</P> Tue, 29 Nov 2016 18:05:35 GMT SteveDenham 2016-11-29T18:05:35Z https://communities.sas.com/t5/Statistical-Procedures/Proc-Mixed-and-missing-data-with-crossover/m-p/311002#M16426 <P>I am analyzing data from a two treatment, two period crossover design. &nbsp;I have bioavailability parameters of area under the curve, peak time, peak value etc. &nbsp; The protocol evaluable subset is based on different parameters, therefore it is possible 1 or more subjects may have a missing&nbsp;value on one of the treatments for one or more of the bioavailability parameters. &nbsp;Can they still be used in the proc mixed model for that parameter or must I subset my data for each parameter to only complete cases.</P> Fri, 11 Nov 2016 15:22:13 GMT https://communities.sas.com/t5/Statistical-Procedures/Proc-Mixed-and-missing-data-with-crossover/m-p/311002#M16426 Ohio_Stats 2016-11-11T15:22:13Z https://communities.sas.com/t5/Statistical-Procedures/Proc-Mixed-and-missing-data-with-crossover/m-p/315301#M16615 <P>Provided the data are "missing at random", then the estimates from PROC MIXED are valid. &nbsp;However, if the missing data are not at random (say due to cumulative toxicity and subject dropout), then you should consider other options.</P> <P>&nbsp;</P> <P>Steve Denham</P> Tue, 29 Nov 2016 18:05:35 GMT https://communities.sas.com/t5/Statistical-Procedures/Proc-Mixed-and-missing-data-with-crossover/m-p/315301#M16615 SteveDenham 2016-11-29T18:05:35Z