1. Using Longitudinal Data for Evaluating Policy Changes and Other Interventions

2. Longitudinal Data Sources  From Prescriptions  From Inventory (Stock) Cards  From Hospital Information System  Master Drug File  Dispensing Data  Drug names  Number of units dispensed  Cost  Date & Time

3. Disadvantages of Using Prescriptions  consume time & labor  Illegible handwriting  Need re-calculation Advantages of Using Prescriptions Primary source of data get more data than computer system ( at that time) such as prescriber’s identification

4. Disadvantages of Using Stock Card  consume time & labor  Different basic information  Generic names  Packaging size  Need re-calculation Advantages of Using Stock Card Available all the time in the pharmacy

5. Disadvantages of Using Hospital Information System  Inappropriate designed for research  Incomplete data  Some data were deleted for backup space  restricted personal access Advantages of Using Hospital Information System Save time & labor for data collection No need of sampling Data are in a computerized format.

6. Steps for Using Hospital Information System  Data checking by using a short period of current data from different program or different sources  Cleaning data  Matching files  Making a new file by MS-Access  Transfer to MS-Excel  Data analysis

7. Drawing data from hospital information system

8. Update the master drug file and adding subclass code

9. Setup tables Table of Date Table of study drugs

10. Setup Tables

11. Setup query by linking tables Get output

12. Table of output

14. Results

15. Summary Using longitudinal data for evaluating policy changes and other interventions is very useful because it shows all changes over time and data from computerized hospital information system makes this kind of research much easier and bring more precise results if the data are kept in a well designed system. Recommendation Researchers should share ideas in designing the computer system to make it possible to draw the correct data from each field and monitoring drug use will consume less time and energy.