National Invitational Conference on Long-Term Care Data Bases: Conference Package. VI. FILE STRUCTURE AND ACCESS


The public use form of the NLTCS is found on two separate tape files. The first is a rectangular tape file which contains, on a person based record, all survey data for persons in the longitudinal two cross-sectional samples (N=25,401). A rectangular file was created in order to facilitate the processing of the tape by persons with limited programming resources. That is, the original version of the file released from the Census Bureau has six record types (sample person, caregiver/children, and household members, separate by survey year). Each of these files has different numbers of cases. In order to use the data from the caregiver file with data on the individual, one had to write a program linking across the two record types. In the current file all record types are already linked together in one large record. Clearly we have attempted to trade off between a less compact form of data storage (there will be many more blank fields in such a rectangularized file) for greater ease in processing.

The second type of file is that containing the Medicare Part A bill files. This file is not person based since there can be up to 120 bills for a given person. Rather this file is bill-based and retains all the data (e.g., exact beginning and end dates) for each service episode. Certain standard edits have been performed on this file. Within each individual the bills are sorted by transaction type, then admission date. Thus, to use the bill data with the survey record one must perform the linkage operation using special survey identifiers that are found on both files.

The two files are available separately in EBCDIC form on 6250 bpi tape with standard labels from NTIS. The documentation includes instructions to the interviewers, copies of all survey instruments, instructions on sample weight calculations, and detailed codebooks on the rectangular survey and bill files. In addition there is a technical write-up on the creation of the file and its logical structure.