Quality and comprehensiveness of the National Drug Code Directory on magnetic tape.

The quality and comprehensiveness of the FDA's National Drug Code Directory (NDCD) in magnetic tape form was evaluated. The internal quality of the tape was measured by performing cross-checks of the four record types found on the tape and by checking for the presence of "illegal" characters. The comprehensiveness of the tape was evaluated by determining the extent to which a sample of items from nine community and hospital pharmacies could be matched with code numbers on the NDCD tape. A second test of comprehensiveness measured the match rate between the shelf stock sample and National Drug Code (NDC) numbers in a magnetic tape supplied by a regional wholesaler. External quality was measured by comparing the NDC numbers on the containers of items from the shelf sample with the corresponding information in the NDCD tape. More than 300 discrepancies among the four types of records were discovered, and more than 100 "illegal" characters were present in each of the four record types. Matches on the NDCD tape could be found for 80% of the items in the shelf stock sample and 69.5% of the items in the tape supplied by the wholesaler. A total of 156 errors were discovered when the codes on containers in the shelf sample were matched with the NDCD tape information, yielding an error rate of 6.5%. Because of the 6.5% error rate, the usefulness of the NDCD tape is questionable. Since only 80% of an off-the-shelf sample of drugs had matches on the NDCD tape, about 20% of drug products would have to be matched with some other information source. How these figures for the NDCD tape compare with figures for proprietary tapes is not known.