Cerebral Performance Category—Extended (CPC–E): A Novel Tool to Measure Outcomes in Cardiac Arrest Survivors

SIGNIFICANCE: Our research addresses a critical issue in outcomes research: a lack of a valid and reliable tool to accurately and comprehensively measure outcomes after cardiac arrest (CA). We have addressed this issue by developing a multidimensional, simple, pragmatic, CA-specific tool to catalog outcomes: the Cerebral Performance Category—Extended (CPC–E).

INNOVATION: CA is the most common cause of death in North America. Although aggressive medical treatment has improved survival after CA, many survivors experience life-long debilitating impairments and disability. Yet, outcome evaluations have primarily focused on survival, with impairment and disability outcomes receiving little attention. Short-term outcome assessment is critical for decision making regarding discharge disposition and rehabilitation services, whereas long-term outcome assessment is critical to evaluate the efficacy of interventions. The CPC–E provides an accurate and comprehensive measurement of short- and long-term outcomes to inform research and clinical practice in rehabilitation and critical care medicine.

APPROACH: Our objective was to develop a new instrument with content validity, interrater reliability, and clinical utility to measure outcomes in CA survivors. Optimizing resuscitation efforts to reduce mortality has received a great deal of attention, fueling the need to measure and understand short- and long-term outcomes after CA.

METHOD: We used a survey tool design, and the setting was a Level I trauma hospital. Tool-development participants were 25 clinical and research experts in the field of resuscitation science, critical care medicine, and cognitive and cardiopulmonary rehabilitation. For the examination of test–retest reliability and clinical feasibility, participants were 25 CA survivors. A literature review was used to identify potential domains. Levels and descriptors were identified for each domain. The tool was reviewed by the expert panels in iterative rounds. Feedback from the expert panel members was collated at the end of each round, and the CPC–E was revised. Interrater reliability and clinical feasibility of the CPC–E were tested by administering the tool to CA survivors prior to hospital discharge. Intraclass correlation coefficients and descriptive statistics were used to examine interrater reliability and clinical feasibility, respectively.

RESULTS: Near 100% consensus was obtained from the expert panels prior to finalizing the CPC–E. The CPC–E has 10 independent domains: Alert, Logical Thinking, Attention, Short-Term Memory, Motor, Basic Activities of Daily Living, Mood, Fatigue, Complex Activities of Daily Living, and Return to Work. Each domain has five levels, with 1 being the best response for the domain and 5 being the worst. Interrater reliability for the domains is excellent (n = 25, range = .80 to 1.0). The CPC–E took a mean of 6.03 min (SD = 1.67 min) to administer and score. No missing data were reported, and clinicians reported that it was easy to administer and use.

CONCLUSION: The CPC–E is an efficient, yet comprehensive, tool to measure outcomes after CA. Clinically, the multidomain CPC–E yields a profile of outcomes at the time of discharge. The CPC–E profile “signals” a referral to rehabilitation or a clinical or community support service associated with a particular domain. Future studies will establish the psychometric properties of the CPC–E, including responsiveness to change.