Changes in Health-Related Quality of Life (HRQoL) Between an Initial and Six-Month Follow-Up Survey in an Observational, Community-Based Study of Patients with AL Amyloidosis
Authors: White Michelle K. , Bayliss Martha , McCausland Kristen , Oliver Colin , Guthrie Spencer D. 
Published: November 2019

Introduction

Light-chain (AL) amyloidosis is a rare disease in which misfolded light chains are deposited in tissues, which may lead to organ failure, disability, and death. We present changes in health-related quality of life (HRQoL) between an initial and a six-month follow-up survey from an observational, community-based study of patients with AL amyloidosis.

Methods

We partnered with patient advocacy groups to recruit a diverse sample of AL amyloidosis patients (n = 341 initial, n=226 at six-months; 66%) to participate in a non-interventional, community-based study. Online surveys were used to assess demographics, disease and treatment characteristics, and health-related quality of life (HRQoL). HRQoL measures included the patient global assessment of change (PGAC), a five-level ordinal item that asks patients to rate how much their condition has improved or worsened since their initial survey, and the SF-36v2® Health Survey (SF-36v2). The SF-36v2 measures HRQoL across eight scales and two component summary scores of functional health and well-being. Higher scores represent better functioning. Paired t-tests were used to examine significant changes within the full sample and key subgroups. ANCOVA methods, controlling for baseline scores, were conducted to compare changes for the following groups: 1) recently treated patients who received treatment during the past year vs. those whose most recent treatment was more than one year ago; and 2) patients who reported improvement vs. worsening over the six-month period on the PGAC. Analysis of variance was used to compare the SF-36v2 scores from AL amyloidosis patients to a sample representing a general population (GP) norm. The GP data were adjusted to the age and gender distribution of the patient sample using separate ordinary least-squares regression models, with each SF-36 scale or summary score as a dependent variable.

Results

At six-month follow-up, patients were 56.3% female, 91.6% white, and an average of 61.3 years of age. Patients' average time since diagnosis was 5 years, and almost half had three or more organs affected by AL amyloidosis (48.7%). The most reported symptoms were fatigue (81.9%), shortness of breath (52.7%), and numbness of arms and legs (46.2%). Over a quarter of patients had received ≥ 5 treatment series (26.1%), and about half were currently or had recently received treatment (49.1%), with 44.7% of patients currently in complete hematologic response. Nearly a third (31.3%) of patients reported that their AL amyloidosis had somewhat or very much improved since the initial survey and 21.0% described their condition as somewhat or very much worse.

No significant changes in SF-36v2 scores were observed in the full sample after adjusting for multiple comparisons. Given the stability of SF-36v2 scores over time, significant deficits existed at both baseline and follow-up relative to a GP (Figure 1).

For most scales, the SF-36v2 scores changed positively among patients who described their condition as improved and declined among those whose condition reportedly worsened (Figure 2). Mean change differed significantly by improvement status for Physical Functioning, Role Physical, General Health, and Vitality scales, as well as the Physical Component Score (P<0.05 for all).

Mean changes in the General Health scale of the SF-36v2 differed significantly by time since last treatment (P=0.003), where the scores declined among recently treated patients and improved among those treated more than a year ago (-0.9 vs. 1.2, respectively).

Conclusions

This study describes patients with AL amyloidosis in a community-based online study and provides insight into changes in HRQoL over a six-month period. Since this is a non-interventional study with almost half of patients in remission, we examined change in HRQoL with three approaches (full sample, by time since last treatment, and by patients' self-assessment of their condition). Although there was little significant change in HRQoL in the six-month period, positive changes were observed among patients who described their condition as improved. Furthermore, significant deficits in HRQoL persisted over time. It may be that six months is not a long enough period to observe change, particularly in a sample where the majority of patients are not newly diagnosed. Our study will continue to follow these patients through 24 months post-study entry which may provide a broader view.

Disclosures

White: Prothena Biosciences Inc: Research Funding. Bayliss:Prothena Biosciences Inc: Research Funding. McCausland:Prothena Biosciences Inc: Research Funding. Oliver:Prothena Biosciences, Inc.: Employment, Equity Ownership. Guthrie:Prothena: Employment, Equity Ownership, Other: Leadership.