Something Old, Something New, Something Borrowed
It was 1979 and, amongst other achievements, the McDonald’s Happy Meal arrived on the fine dining scene. While children around the world continued to eat inexpensively and poorly, other more beneficial, socially relevant activities were occurring. J.W. Vaupel studied populations whose members differ in their endowment for longevity. His research led to a new observation that life expectancy was not the result of currently available health and safety interventions alone but rather individuals age at different rates and die at variable times. In 1979, this new observation, gave rise to the term “frailty” to summarize unmeasured variability in the risk of death of people at the same age.
Over the intervening decades, as frailty research continued, this meaning of frailty was generalized to represent the risk of an adverse outcome occurring for people with the same degree of exposure. Rockwood and Howlett summarize this history and explain the deficit accumulation model of frailty, the model presented by Patient Pattern. It is the model used in the research presented below where we learn about another novel and interesting observation about frailty.
Until recently, the deficits employed to measure frailty were selected from a variety of domains to identify decline in multiple systems. The interchange in deficits provided mathematical flexibility as long as it was a health deficit, increased with age, and associated with death or another adverse outcome – falls, institutionalization, weight loss, etc. Models of aging and trajectories of frailty are variable but studies indicate that for most people aging is slow and sudden increases in frailty are unusual. And here research indicates something new and valuable for those of us who incorporate frailty into our care plans and want to communicate and address end-of-life care when appropriate.
In 2018, Stow was studying the trajectory of change in the frailty index itself. He and others wanted to know if the past frailty trend impacts the future trend, and if it matters. Understanding the meaning of rate of change, of interest to researchers, offers value to us in our desire to anticipate and be proactive in our approaches. This research concluded that people over 75 with frailty have a distinctive frailty trajectory in the last 12 months of life. The retrospective study examined the monthly electronic Frailty Index (eFI), from the Deficit Accumulation Model of Frailty, of 13,149 people who died in the previous year. Three distinct frailty trajectories were identified:
- Rapid rising eFI – 2.2% / month (baseline eFI 21%) – 180% increase in mortality in 1 yr
- Moderate rising eFI – 0.7% / month (baseline eFI 26%) – 65% increase in mortality in 1 yr
- Slow rising eFI – 0.1% / month (baseline 26%) – stable – not associated with mortality
While the single measurement of frailty and its association with mortality have been extensively studied, research into the association between the longitudinal trending of frailty and mortality will add to our understanding of frailty. From this research, borrowed and cited, the takeaway message is important for clinicians caring for the frailest populations. If we see a rapidly rising Frailty Risk Score, average 1% monthly, consider that the patient is twice as likely to die in the next twelve months as the patient with a stable Frailty Risk Score. For rapid rising frailty patients the research indicated an initial monthly increase in eFI of 2%, prior to slowing around 8-9 months prior to death. This small proportion (2.22% of sample) represents a small but important segment of those we care for but our awareness of their risk of dying is valuable for our plan of care.
Even though the positive predictive value and sensitivity of the rapidly rising trajectory is significant, it should be combined with our clinical judgement. Some patients are resilient to higher but stable levels of frailty and here our clinical assessment coupled with the insights from the data should guide our approach to their care and the timing of our communications on end-of-life frailty-informed decision making.
As we follow frailty research and learn from new observations, we invite you to check out Patient Pattern for more information about frailty and how it can become part of your clinical approach to care.
Our team at Patient Pattern would like to acknowledge the contributions of Dr. Arnold Mitnitski to the research that gave us the Deficit Accumulation Model of Frailty. His untimely death on May 26, 2021, leaves us saddened but grateful for all we have learned from his decades of research. His brilliant mind and kind approach to colleagues will be missed. https://www.dal.ca/sites/gmr/our-team/arnold-mitnitski.html