Seminar ER2: Clinical Pharmacy Services: absence of evidence is not evidence of absence

Linked to EAHP Statements

Section 4 – Clinical Pharmacy Service: Statement 4.8 
Section 6 – Education and Research: Statement 6.4

ACPE UAN: 0475-0000-18-025-L04-P. A knowledge based activity.

Abstract

Clinical pharmacy services include interventions such as medication reviews, patient consultations and adherence, etc. The clinical pharmacy services are often complex and non-specific, and they may be delivered in collaboration with other health care professionals in multidisciplinary teams. The services often seek to improve symptoms control, optimize the use of medications and reduce medication-related risks. However, the effect of clinical pharmacy services is often evaluated using “hard” endpoints such as mortality and hospital admissions, despite that these measures may not necessarily be affected by clinical pharmacy services. Even though we know that pharmacist interventions do save lives, it is probably a rare outcome. Hence, the benefit of clinical pharmacy services should be assessed using other outcomes measures e.g. health-related quality of life, adverse drug events, drug-related problems, etc.

Evaluating clinical pharmacy services using outcome measures such as mortality or hospital admissions require large sample sizes to avoid type II errors. However, clinical pharmacy studies are often assessed by using sample sizes too small to capture a potential effect.

Consequently, no effect shown as a result of the evaluations does not necessarily indicate that the clinical pharmacy services are ineffective but rather that an insufficient number of patients were included to capture a potential effect, or suboptimal outcome measures may have been chosen.

Even though absence of evidence is not evidence of absence, it is essential for clinical pharmacists to consider alternative strategies in documenting the effect of their services to ensure continuation of these in hospital practice.

Learning objectives

After the session, the participant should be able to:
• describe methods of evaluating clinical pharmacy services;
• discuss the importance of choosing optimal outcome measures when planning clinical pharmacy service studies;
• provide examples of consequences when the effects of clinical pharmacy services are not documented;
• list alternative options to traditional outcome measures (mortality, hospital admissions etc.); and,
• explain why absence of evidence is not evidence of absence.

Educational need addressed

Clinical pharmacists are from time to time confronted with needs to document the effect of their services. However, interpretation of clinical pharmacy studies may be challenged by the methodology used, which the current seminar will address.

Keywords: clinical pharmacy services, evaluation, complex interventions, methodology, process measures, outcome measures.