Development of an explicit tool assessing potentially inappropriate medication use in Hong Kong elder patients

Potentially inappropriate medication (PIM) use has adverse effects on health, particularly in elder patients. Various country-specific explicit criteria have been developed to measure the appropriateness of prescribing worldwide. However, it is difficult to apply the criteria developed from other regions to measure and guide the local prescribing practice in Hong Kong. This study aims to develop a Hong Kong-specific PIM assessing tool from previously published criteria and validate this tool using the modified Delphi method.

A disease-oriented Hong Kong-specific preliminary PIM list was developed based on nine sets of reference criteria selected from a literature review. Any medication or medication class appeared in at least two sets of the reference criteria as well as its related medical conditions were selected as PIM candidates. After examining the availability of PIM candidates by the Hong Kong Hospital Authority drug formulary, the Hong Kong-specific preliminary PIM list was validated by a two-round of modified Delphi process. Eight experts from different specialties were invited to rate the degree of inappropriateness of each PIM candidate using a five-point Likert scale. The experts were also encouraged to propose therapeutic alternatives and new PIM candidates not covered by the preliminary PIM list. The PIM candidates that the expert panel didn't reach consensus on were excluded from the final Hong Kong-specific PIM list.

After two rounds of the Delphi process, eight PIM candidates remained questionable and thus were excluded from the PIM list. The final Hong Kong-specific PIM list included a total of 164 statements applicable to older adults aged 65 years or above, among which 77 were under PIMs independent of diagnoses, and 87 were under PIMs considering specific medical conditions.

The Hong Kong-specific PIM list can be used as a quality measure and an educational tool to improve the local prescribing quality. Further studies should validate its association with adverse health outcomes in clinical and research settings.