Polypharmacy: The Practitioner's Perspective

Jessica L. Clement, RN BSN

The number of older patients (> 45 years) in the global population is increasing and the proportion of patients from this age group being seen at trauma centers is also increasing. Continuously evolving sophistication of modern management of chronic medical conditions has resulted in escalating simultaneous use of multiple medications and the emergence of the phenomenon of polypharmacy. 

Current understanding of how polypharmacy in conjunction with comorbidities may influence trauma outcomes is limited, however there is a growing body of evidence suggesting older trauma patients are at increased risk for medication-related adverse effects, increased overall complications, hospital readmission, and mortality. 

Polypharmacy has generally been defined as concurrent administration of more than 5 medications, however this definition is not standardized, and various iterations of it are observed in the literature.  This inconsistency may be a reflection of the lack of evidence for co-administered drugs correlating with risks and/or adverse drug events. The literature available describes many potential hazards related to the simultaneous use of multiple medications in the middle age and elderly populations. 

Some of the major risks of polypharmacy include adverse drug reactions and interactions, occurrence of manifestations of syndromes, under prescribing of recommended drugs, unintended medical errors, poor patient adherence, cognitive and functional decline, and increased need for healthcare utilization leading to greater costs and higher mortality. 

With the use and development of medication reconciliation, the comorbidity-polypharmacy score (CPS) can easily be calculated and has been proposed as an aide for outcome prediction, triage, and discharged planning in the injured patient population. CPS may function as an objective measure of the “cumulative severity” of all comorbid conditions, reflecting the patient’s “physiologic age”.  Evidence suggests triage strategies primarily focused on the patient’s chronological age are imperfect and adding physiologic age may improve their overall predictive accuracy. Retrospective studies have shown that CPS may assist in identification of older trauma patients at risk for poor outcomes and more likely to require additional resources upon discharge. A readily calculated and objective tool like CPS can assist with the early identification of older trauma patients who may be at risk for poorer outcomes and undertriage. According to the article, when properly validated and applied, such instrument could not only affect patient outcomes, but could also aid hospital staff in more appropriately deploying resources needed for effective discharge planning and readmission reduction (Justiniano, 2015). 

The Charlson Scoring System (CSS) and a number of associated modifications have been used in assessing the role of the comorbid conditions in predicting patient outcomes. The calculation of CSS involves a procedure that requires the identification of several specific comorbid conditions, scoring each according to pre-determined point weights, and adding additional predefined points for the patient’s age group. The CSS does not take into account the individualized disease severity for the patient’s comorbidities, meaning the quantification of disease severity is limited. Holmes describes the Charlson index’s categorization of relative disease severity as “dated” (Holmes, 2014).  The weighting provided for different ages in the Charlson index is fixed, which is argued because patients considered “old” within the last 20 years are more commonly healthy and active now than before in history. Originally, the index was intended for predicting mortality in a narrowly defined, small cohort of patients. However, the CSS has been successfully applied to claims data, in-hospital mortality, use of blood products, lengths of hospital stay, discharges, and to predict short-term outcomes. Both the comorbidity-polypharmacy score (CPS) and Charlson Scoring System (CSS) are very close in their estimation of outcome prediction. 

Elixhauser et al. has also developed an approach to use comorbidity data in conjunction with administrative data to aid in outcome prediction (Elixhauser, 1998). This group created an approach that started with identification of five key concepts related to a patient’s hospitalization including the primary reason for hospitalization, the severity of the principal diagnosis, complications of care, unrelated comorbidities that are present on admission but do not impact resources, and important comorbidities/conditions not related to the reason for admission but may impact resources or cause a poor outcome. This group was able to identify and develop 30 comorbidity measures that were significantly associated with greater hospital lengths of stay, higher hospital charges, and increased mortality. Subsequently, the methodologies of Elixhauser as well as CSS may contain “difficult-to-quantify” biases, leading to controversy. The Elixhauser formula has the ability to better focus on individual contributing variables and lack of reliance on weighted scoring. 

According to Stawicki et al., the CSS, CPS, and Elixhauser score are all subject to important biases in the acute trauma setting (Stawicki, 2015). Wider implementation of electronic medical records (EMR) may help in this domain however skepticism should be used in regards to the initial estimation of such scores due to the high probability of incomplete initial information. 

A number of studies have been conducted in regards to methods used leading to the indication that any kind of scoring system performs well if used with “local coding and diagnostic practices” of which both the CSS and Elixhauser index are noted for performing comparably well.  Modified or combining scoring systems or indices may be helpful, especially in the elderly population. Researchers state that these tools can be combined with other strategies such as modified geriatric trauma criteria to achieve the optimum predictive power and have the potential to positively affect and enhance care for the older injured patient (Ichwan, 2015). 

In closing, as the global population continues to age, patients seen at trauma centers will be increasingly more likely to present with pre-injury multi-morbidity and polypharmacy. Tools such as the comorbidity-polypharmacy score (CPS), Charlson Scoring System (CSS), and Elixhauser index may be employed by trauma and emergency practitioners to more accurately characterize the physiological age of a patient, in which research has stated the addition of the patient’s physiologic age in conjunction with chronological age may improve overall predictive accuracy. The assessment of chronic health conditions and comorbidities will become essential and will complement the traditional anatomic and physiological assessment of the routine patient evaluation.  

References:

• Elixhauser, A., Steiner, C., Harris, D. R., & Coffey, R. M. (1998). Comorbidity Measures for Use with Administrative Data. Medical Care, 36(1), 8-27. doi:10.1097/00005650-199801000-00004Comorbidity Measures for Use with Administrative Data. Medical Care, 36(1), 8-27. doi:10.1097/00005650-199801000-00004
• Evans, D. C., Cook, C. H., Christy, J. M., Murphy, C. V., Gerlach, A. T., Eiferman, D., Lindsey, D. E., Whitmill, M. L., Papadimos, T. J., Beery, P. R., Steinberg, S. M. and Stawicki, S. P. A. (2012),    Comorbidity-Polypharmacy Scoring Facilitates Outcome Prediction in Older Trauma Patients. J Am Geriatr Soc, 60: 1465–1470. doi:10.1111/j.1532-5415.2012.04075.xComorbidity-Polypharmacy Scoring Facilitates Outcome Prediction in Older Trauma Patients. J Am Geriatr Soc, 60: 1465–1470. doi:10.1111/j.1532-5415.2012.04075.x
• Holmes, M., Garver, M., Albrecht, L., Arbabi, S., & Pham, T. N. (2014). Comparison of Two Comorbidity      Scoring Systems for Older Adults with Traumatic Injuries. Journal of the American College of Surgeons, 219(4), 631-637. doi:10.1016/j.jamcollsurg.2014.05.014Comparison of Two Comorbidity      Scoring Systems for Older Adults with Traumatic Injuries. Journal of the American College of Surgeons, 219(4), 631-637. doi:10.1016/j.jamcollsurg.2014.05.014
• Housley BC, Kelly NJ, Baky FJ, Stawicki SP, Evans DC, Jones CD. Comorbidity-Polypharmacy Score Predicts Readmission in Older Trauma Patients. 2015Comorbidity-Polypharmacy Score Predicts Readmission in Older Trauma Patients. 2015
• Ichwan, B., Darbha, S., Shah, M. N., Thompson, L., Evans, D. C., Boulger, C. T., & Caterino, J. M. (2015).    Geriatric-Specific Triage Criteria Are More Sensitive Than Standard Adult Criteria in Identifying Need for Trauma Center Care in Injured Older Adults. Annals of Emergency Medicine, 65(1). doi:10.1016/j.annemergmed.2014.04.019Geriatric-Specific Triage Criteria Are More Sensitive Than Standard Adult Criteria in Identifying Need for Trauma Center Care in Injured Older Adults. Annals of Emergency Medicine, 65(1). doi:10.1016/j.annemergmed.2014.04.019
• Justiniano CF, Coffey RA, Evans DC, Jones LM, Jones CD, Bailey JK, et al. Comorbidity-polypharmacy score predicts in-hospital complications and the need for discharge to extended care facility in older burn patients. J Burn Care Res. 2015;36:193–6. Comorbidity-polypharmacy score predicts in-hospital complications and the need for discharge to extended care facility in older burn patients. J Burn Care Res. 2015;36:193–6.
• Stawicki, S. P., Kalra, S., Jones, C., Justiniano, C. F., Papadimos, T. J., Galwankar, S. C., … Evans, D. C. (2015). Comorbidity polypharmacy score and its clinical utility: A pragmatic practitioner’s perspective. Journal of Emergencies, Trauma, and Shock, 8(4), 224–231. http://doi.org/10.4103/0974-2700.161658Comorbidity polypharmacy score and its clinical utility: A pragmatic practitioner’s perspective. Journal of Emergencies, Trauma, and Shock, 8(4), 224–231. http://doi.org/10.4103/0974-2700.161658