Re: SAS program or SAS macro to prepare NonMem ready data

From: "Nick Holford" n.holford@auckland.ac.nz Subject: Re: [NMusers] SAS program or SAS macro to prepare NonMem ready data Date: Wed, December 8, 2004 2:04 pm Elliot, I am sure SAS (or almost any other programming language) can be used to write code to format data for NONMEM. However, as several people have pointed out their is no single piece of code that can do this for any input. There are many things that I do while formatting data for NONMEM -- this includes consistency checking (e.g. are weights in a reasonable range?), putting out error messages for invalid data (e.g. positive concentration of drug before any dose has been given), transformation of values (e.g. some data sets have weights in both kg and pounds [and if one is lucky a units indicator too!]), making decisions based on all the records for a given individual (e.g. dosing records are supplied but no conc records so I drop all these records from the NONMEM dataset because they add nothing to a PK analysis). In addition to these data driven needs there are model specific items that need to be put in the data set e.g. CMT items depend on the model structure, additional records are required to initialize differential equations. IMHO the programming challenges for dealing with real NONMEM data sets and non-trivial models (i.e. more than simple PK) demand the NONMEM analyst either writes his/her own data formatting code or works with someone with these skills. The ability to automate data formatting (and therefore demonstrate exactly how original data is transformed) is an essential part of any quality based NONMEM analysis. Manual manipulation of data items in Excel should be discouraged. Nick -- Nick Holford, Dept Pharmacology & Clinical Pharmacology University of Auckland, 85 Park Rd, Private Bag 92019, Auckland, New Zealand email:n.holford@auckland.ac.nz tel:+64(9)373-7599x86730 fax:373-7556 http://www.health.auckland.ac.nz/pharmacology/staff/nholford/