| Abstract: | Background/Aims The HMO Research Network (HMORN) Virtual Data Warehouse (VDW) is a series of dataset standards and automated processes that aim to streamline the process of multi-site research. The Pharmacy file contains data on all outpatient dispensings captured within the HMORN. The objective was to assess the overall quality and completeness of the Pharmacy file. Methods The VDW Pharmacy Working Group created a data verification protocol to assess the overall quality and completeness of Pharmacy file data (e.g., to identify missing data or out-of-range values). A distributed SAS program was run at each HMORN site that maintains a VDW Pharmacy file (n=14 of 19 HMORN sites), and de-identified summary data were returned for analysis. Pharmacy file variables that were assessed included National Drug Code (NDC), days supplied, amount dispensed, and prescribing physician (which joins to the VDW Provider Specialty file). An "invalid" NDC was defined as any value not having exactly 11 digits or containing a non-numeric character. The days supplied variable was considered out-of-range if the value was < 0, = 500, or missing. Amount dispensed was defined as out-of-range for values < 0, = 1000, or missing. Results Fourteen HMORN sites had Pharmacy data from 2000-2009 and participated in this analysis; some sites had > 20 years of data. There were 93.4 million dispensings in 2009, with an average of 7.8 million dispensings per month among 3.1 million monthly users (average per user: 2.6 dispensings per month; range across sites 2.3-5.8). Across all sites from 2000-2009, 0.082% (712,131/870,182,026) and 0.072% (629,656/870,182,026) of dispensings had missing or "invalid" NDCs, respectively; and 0.083% (724,210/870,182,026) and 0.315% (2,736,756/870,182,026) had out-of-range days supplied and amount supplied, respectively. The prescribing physician was identified in 96% (1,038,725,660/1,079,370,265) of all dispensings. The prescriber's specialty was identified in 62% (539,944,688/870,182,078) of dispensings overall and improved from 61% (46,678,731/77,078,104) in 2000 to 63% (60,160,629/95,867,812) in 2009. Discussion The VDW Pharmacy file has excellent overall data quality results, and has improved in identification of prescriber specialty. It has measurably comprehensive and consistent outpatient dispensing data across 14 HMORN sites. |
