Pharmacists Are Associated With Reduced Mortality in Critically III Patients: Now What?

To the Editor:

Almost 2 decades ago, the Society of Critical Care Medicine’s position article on critical care pharmacy services established pharmacists as integral components of the interprofessional care team for critically ill patients (1). Clinical value has been repeatedly established in patient outcomes (e.g., length of stay, duration of mechanical ventilation, and mortality) and in medication-related outcomes (e.g., cost avoidance, adverse drug event avoidance, and reduced medication errors) (2).

In a recent issue of Critical Care Medicine, Lee et al (3) reported the results of the first meta-analysis to evaluate the impact of pharmacist inclusion in critical care teams on patient mortality. The authors observed that critical care pharmacy services yielded an odds ratio for mortality of 0.78 (95% CI, 0.73–0.83; p < 0.00001), without significant heterogeneity (I² = 35%; p = 0.13).

Although heartening to see continued evidence for the vital role of pharmacists, the knowledge gap now lies not in proving the value of critical care pharmacists, which Lee et al (3) and others before them have unequivocally shown, but in investigating the best modalities of critical care pharmacist “implementation.” Notably, the studies included by Lee et al (3) were primarily of a pre-post design and thus evaluated only the presence versus absence of pharmacy services. We are left with many unanswered questions:

1. What is the optimal pharmacist to patient ratio?

2. How should pharmacist effectiveness be measured?

3. Should a clinical pharmacist be staffed overnight, on weekends, or over holidays?

4. How much time should a pharmacist devote to or be expected to spend on clinical activities (e.g., rounding) versus nondirect patient care activities (e.g., quality improvement, research, education)?

Although other professions have established provider to patient ratios within the ICU, making it inconceivable for shifts to go without a nurse or intensivist, no such consideration of a pharmacist’s necessity exists (4). Current literature reports a wide range of critical care pharmacist ratios, and a recently published survey of critical care pharmacy services showed marked heterogeneity in practice models and found the most commonly reported pharmacist to patient ratio to be 1:16–20, which may be too high (5). The survey also found that higher pharmacist to patient ratios were associated with perceptions of inappropriately high workload and unsafe conditions for patients (5).

This knowledge gap in practice models may result from lack of objective measurement tools to predict pharmacy workload. Recently, a tool was designed and validated to assess pharmacist workload based on medication regimen complexity and has been shown to correlate with pharmacist interventions (6). The MRC-ICU and tools like it may be a step in the direction of identifying safer and more appropriate pharmacist to patient ratios. The possibility exists that hospitals conduct internal quality improvement initiatives and have developed internal tools and dashboards that optimize pharmacy services, and if so, this letter acts as a call for the results of Lee et al (3) to be acted on, and these strategies to be investigated and disseminated.