Will decision support in medications order entry save money? A return on investment analysis of the case of the Hong Kong hospital authority.

The computerized medications order entry system currently used in the public hospitals of Hong Kong does not have decision support features. Plans are underway to add decision support to this system to alert physicians on drug-allergy conflicts, drug-lab result conflicts, drug-drug interactions and atypical dosages. A return on investment analysis is done on this enhancement, both as an examination of whether there is a positive return on the investment and as a contribution to the ongoing discussion of the use of return on investment models in health care information technology investments. It is estimated that the addition of decision support will reduce adverse drug events by 4.2 - 8.4%. Based on this estimate, a total net saving of $44,000 - $586,000 is expected over five years. The breakeven period is estimated to be between two to four years.