Background and Importance To date there is no gold standard for rating clinical significance of pharmacy contributions to care.

IMPACCTS (InstruMent for PhArmacy Clinical Contributions To care Significance) is based on the Hatoum scale¹ and consists of five ordered categories or levels, each underpinned by descriptive statements (total of 45 statements).

A robust process to ensure simplicity and clarity of the instrument has been previously reported.²

Aim and Objectives Aim: To complete the validation of IMPACCTS.

Objectives were to:

• demonstrate comprehensiveness of IMPACCTS

• quantify interrater reliability of IMPACCTS

Material and Methods This study was completed February 2022. The study did not require ethics approval.

To assess comprehensiveness, 20 senior pharmacists with prior experience of using IMPACCTS were paired to review 45 scenarios (450 different scenarios in total) and asked to find a corresponding statement, or failing that, a suitable significance level.

For interrater reliability, all 20 pharmacists were given the same 15 detailed scenarios to rate clinical significance. Intraclass correlation statistics (two-way, random effects, absolute agreement, individual) were calculated using Stata v14.

All data were collected via a web survey platform.

Results Comprehensiveness – for all scenarios, at least one person found a statement. For 441/450 (98%) scenarios, both respondents in a pair found a corresponding statement. Out of the nine scenarios where one person from the pair did not find a statement, a level could be assigned for eight of these. Therefore, a statement and/or level could be assigned for 449/450 (99.8%) of the scenarios by all respondent pairs.

Intraclass correlation was 0.71 (95% CI = 0.55, 0.86) which demonstrates moderate to good pharmacist interrater agreement.

Conclusion and Relevance This study demonstrates excellent comprehensiveness and moderate to good interrater reliability of IMPACCTS. These data support readiness of the tool for use in research and practice to assess clinical severity of pharmacy contributions in hospital.

References and/or Acknowledgements 1. Hatoum HT et al. Evaluation of the contribution of clinical pharmacists: inpatient care and cost reduction. Drug Intelligence Clinical Pharmacy 1988; 22(3): 252–9.

2. Mehta R and Onatade R. Content validity of a tool for rating the significance of pharmacists’ clinic contributions in hospital settings. UKCPA Symposium Proceedings; 2016.

Conflict of Interest No conflict of interest.