Health-related Quality of Life: A Developing Standard in Healthcare

Several years ago, while I was enrolled in a graduate course on public health, our instructor showed the class a list of the top-ten causes of mortality in the United States. I created a moment of general discomfort by saying, "You know, we might be able to juggle the order a bit, but ultimately, that top-ten list will always be the same." I wasn't trying to be disruptive, but I felt it was naïve to imply that the healthcare system should attempt to somehow stave off mortality. And even if we could, would those added years add quality to the experience of living?

It's intriguing to see that in recent years the federal healthcare sector has begun to recognize the new challenge of not only extending life but also enhancing its quality. Since 1979, the U.S. Department of Health and Human Services (HHS) has set the nation's ten-year goals and objectives for health promotion and disease prevention through its Healthy People initiatives. Within the Healthy People 2020 literature, there is a report titled "Health-Related Quality of Life and Well-Being." The report begins:

Life expectancy and causes of death have traditionally been used as key indicators of population health. While these indicators provide critical information about the health status of populations, they do not offer any information about the quality of the physical, mental, and social domains of life. Increasing life expectancy has also highlighted the need for other measures of health, especially those that capture the quality of the years lived.¹

Within O&P, this may be welcome news. Our interventions, after all, generally enhance life more than they extend it. But if health-related quality of life (HRQoL) is becoming a new standard against which the value of healthcare services will be measured, it is important that we understand the construct, how it is measured, and the extent to which we can influence it. Recent findings about Duchenne muscular dystrophy (DMD) serve as an ideal starting point.

Duchenne Muscular Dystrophy

At about the same time that I stirred some discussion in my public health class, I wrote a literature review on the lower-limb orthotic management of DMD.² It summarizes the tragedies associated with this diagnosis. Affected boys are generally unremarkable in their presentation at birth and through infancy, reaching their early developmental milestones of rolling over, sitting, and standing in roughly the same timeframes as their unaffected peers. Walking may be delayed during the toddler stage, with pronounced gait deficits observed at 3-5 years of age. At that time, parents report clumsiness or an inability for their sons to keep up with peers. The disease progresses from there.

Initially, walking is characterized by excessive equinus, with some difficulty in swing clearance. The heel strike that should occur at initial contact is progressively replaced by a flatfoot strike, followed by a forefoot strike. Cadence declines. In the coronal plane, the base of support becomes progressively wider, with increasingly exaggerated shoulder sway.

Eventually, progressive contractures and increasing weakness deprive the young men of the ability to walk, and they lose their ability to rise from the floor, climb stairs, and walk independently in approximately one-year intervals. As I wrote in that review:

For a family coping with a disease characterized by a series of crises, the loss of ambulation may represent the biggest crisis since the initial diagnosis. As Gardner-Medwin expressed, "The loss of the boy's ability to walk confirms in a graphic and inescapable way the prognosis they [the parents] had been given and had been hoping against hope might be wrong."²

When ambulation becomes impossible, patients are confined to a wheelchair, and contractures quickly worsen. Untreated, they will die, on average, just shy of their 20th birthdays. With respiratory support and proactive cardiac management they can now survive into their 30s and 40s.³

HRQoL Observed in DMD: The First Glance

Swedish researcher Erik Landfeldt, PhD, and his colleagues succinctly summarize the cumulative impact of DMD by acknowledging that "compared with the reference points of a healthy peer, this life would appear bleak."³ They go on to immediately acknowledge, "However, from the perspective of the affected individuals, who do not know any other life, they may perceive their well-being differently."³

The recent work of Landfeldt et al. was to attempt to quantify the HRQoL among boys with DMD across the disease's spectrum of decreasing ability and health.³ The study in question was comprehensive, drawing from affected boys and their caregivers from the United States (n = 284), the United Kingdom (n = 191), Germany (n = 173), and Italy (n = 122).³ The boys' conditions spanned the progressive spectrum of the disease. Four categories of ambulatory status were established, each represented by roughly one-quarter of the surveyed population: early ambulatory (approximately 5-7 years old), late ambulatory (approximately 8-11 years old), early nonambulatory (approximately 12-15 years old), and late nonambulatory (approximately 16 years old or older).

Among the most important findings observed by the authors was the importance of how HRQoL is assessed. For example, the authors asked the caregivers to subjectively assess the young men's current health and mental status. If the reader only makes it through the first three pages of the manuscript, the observations are striking. When parents are asked about the general health of their sons with DMD, the answers are largely good, very good, or excellent. This might be expected for the boys who are still in the early ambulatory period of the disease, and in fact, over 95 percent of the parents with boys in this stage rated their sons' current health at one of these levels. However, the decrease in the general health assessment that was expected with disease progression is much less than might be reasonably assumed.

During the late ambulatory period, over 90 percent of the boys with DMD are described by their parents as in good, very good, or excellent health. When they reach the early nonambulatory period, this drops off to about 85 percent, where it is unchanged among those in the late nonambulatory period. Even among those 126 boys who were nonambulatory and ventilated, over 75 percent were described to be in good, very good, or excellent health.³

A similarly surprising trend was observed regarding parental reports of current mental status. Over 95 percent of queried parents described their sons with DMD as somewhat happy or happy and interested in life during the ambulatory period. As the disease progressed through the late nonambulatory stage, a happy, interested mental status persevered in 85 percent of the affected boys. Even among those who had been ventilated, over 80 percent were described in those terms.

How is this possible? The authors suggest that a "well-being paradox" is at play, in which individuals and their families progressively adapt their expectations as they accommodate to worsening illness. Alternately, families may be basing their assessment on the trajectory of the disease, assessing the current health state to be better than the expected well-being that will accompany the more advanced stages of DMD.³ An additional observation is that ratings of HRQoL appears to be dependent on how they are assessed.

HRQoL Observed in DMD: The Deeper Look

Fortunately, in addition to the subjective general assessments provided by the parents, the boys and their parents were asked to complete two established HRQoL questionnaires. The first was the Health Utilities Index (HUI®), a 16-item questionnaire that covers such dimensions as hearing, speech, mobility, pain, dexterity, self-care, emotion, and cognition. Importantly, it is a generic measure, indexed against measurements from the general population, that ranges from 0 (dead) to 1 (perfect health).

The second instrument was the Pediatric Quality of Life Inventory (PedsQL). This instrument is specifically designed to assess children with neuromuscular disorders and consists of questions related to disease progression and symptoms, communication, and family resources. Total scores range from 0-100, where higher scores indicate a higher HRQoL. When the boys and their parents are empowered to provide a more detailed assessment of how they are doing, a different picture emerges.

For example, when considered according to ambulatory ability, the average HUI score of 0.75 during the early ambulatory period dips to about 0.65 during late ambulation and then drops precipitously to about 0.25 during the early nonambulatory period and to 0.15 during the late nonambulatory period.³

Similar trends were observed with the mean PedsQL scores, which ranged from 73 during the early ambulatory stage and declined to 26 in the late nonambulatory period.³ However, unlike the HUI and the generalized subjective assessment, both of which were provided by the caregivers, the PedsQL was filled out by the parents and, wherever possible, the boys themselves. Importantly, the caregivers consistently underrated the HRQoL of their sons. In other words, the seemingly inflated assessments of health and mental status described earlier were provided by caregivers that, if anything, tend to underestimate their sons' well-being.

Thus, if the healthcare profession is going to assess the value of its services by its impact on HRQoL, it is extremely important that it be assessed accurately and comprehensively. While most of these young men were considered by their parents to be happy and in good to excellent health, their more scrutinized HRQoL scores (0.15-0.75) lagged considerably behind reference values of healthy Canadian children and young adults (0.94).³

HRQoL Following Amputation

Consistent with the tragic nature of the disease, the declines observed in HRQoL in young men with DMD are surely some of the more dramatic. Similar, though less striking, declines are observed in other neurologic presentations, such as in adults with cerebral palsy and stroke. However, the trends aren't always negative, and it seems appropriate to conclude with a counterexample in which HRQoL has been seen to improve, namely in patients with lower-limb amputations.

Fortington et al. recently reported on a cohort of 82 individuals with an average age of 68 years who underwent lower-limb amputations.⁴ Their HRQoL measure was the Research and Development Corporation measure of Quality of Life (RAND-36), assessed at the time of amputation, and at six- and 18-months post-amputation. The RAND-36 assesses HRQoL across nine domains, each of which are scored between 0-100, with 100 indicating the highest possible quality of life.

While there was modest attrition as some study participants passed away and others dropped out, the authors were able to successfully track RAND- 36 scores over time. In two of the domains, General Health and Mental Health, nonsignificant improvements in HRQoL were reported at the six-month iteration of the assessment. Notably, these domains were much higher than the others at the time of amputation (61 and 71, respectively), leaving little area for improvement.

The remaining domains experienced dramatic and statistically significant improvements. Perceived Health, for example, leapt from 24 to 74, while Pain experienced a similar improvement, from 26 to 74. Social Function also improved substantially from a dismal 12.5 to a more reasonable 50.2. Improvements in Physical Function and Vitality were also observed during the initial six months post-amputation, with the former increasing from 12 to 33 and the latter improving from 47 to 66.⁴

Summary

The aims of healthcare, as dictated by HHS and common sense, are not limited to longevity. The quality of and satisfaction with life are also increasingly recognized for their importance. However, if these paradigms are to be measured to assess the quality of healthcare interventions, it is important that they be accurately and comprehensively assessed. The O&P profession would do well to identify those outcome instruments that will provide the most accurate assessment of the HRQoL in populations we serve.

Phil Stevens, MEd, CPO, FAAOP, is in clinical practice with Hanger Clinic, Salt Lake City. He can be contacted at .

References

1. U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion. Healthy People 2020, Foundation Health Measure Report, Health-Related Quality of Life and Well-Being. www.healthypeople.gov/sites/default/files/HRQoLWBFullReport.pdf
2. Stevens, P. M. 2006. Lower limb orthotic management of Duchenne muscular dystrophy: A literature review. Journal of Prosthetics and Orthotics, 18 (4): 111-9.
3. Landfeldt E., P. Lindgren, C. F. Bell, et al. 2015. Health-related quality of life in patients with Duchenne muscular dystrophy: A multinational, cross-sectional study. Developmental Medicine & Child Neurology, 58 (5):508-15.
4. Fortington, L. V., P. U. Dijkstra, J. C. Bosmans, W. J. Post, and J. H. B Geertzen. 2013. Change in health-related quality of life in the first 18 months after lower limb amputation: A prospective, longitudinal study. Journal of Rehabilitation Medicine, 45 (6): 587-94.