Understanding patient-reported outcome measures in Huntington disease: at what point is cognitive impairment related to poor measurement reliability?

Abstract

Results indicate that the psychometric reliability of PROs can be compromised as HD symptoms progress and cognition declines. Clinicians should consider PROs in conjunction with other types of assessments when total cognition scores exceed critical thresholds.

HDQLIFE and Neuro‐QoL Physical Function Measures: Responsiveness in Persons with Huntington's Disease

“…Given that individuals with more severe disease were more likely to discontinue participation as a result of worsening symptoms (and in many cases the inability to provide informed consent at a later study visit) and that these individuals are precisely the individuals who are experiencing the largest declines in health, we would expect this to negatively impact our findings such that effect sizes are smaller than would be expected for the HD population. This would be consistent with findings in this sample that suggest that the reliability of these PROs can be compromised in those in the later stages of the disease process . Our results are based on a well‐educated, primarily non‐Hispanic White population, limiting possible generalizability to other racial/ethnic groups.…”

“…Specifically, individuals with larger TFC-related declines are also more likely to have advanced disease, and the reliability of PRO scores are adversely affected by cognitive impairment. 45 Our responsiveness data were more robust when examining self-reported HRQOL relative to self-reported change and less robust when examining self-reported HRQOL relative to clinician-rated changes. Findings from other populations suggest that clinicians tend to systematically underestimate patient symptoms and functional decline.…”

“…This would be consistent with findings in this sample that suggest that the reliability of these PROs can be compromised in those in the later stages of the disease process. 63 Our results are based on a well-educated, primarily non-Hispanic White population, limiting possible generalizability to other racial/ethnic groups. In addition, self-reported changes were also closely matched to each physical HRQOL domain, whereas clinician-rated changes reflected functional changes-which are less closely tied to HRQOL constructs-precluding our ability to directly compare the clinical utility of these measures across these 2 different types of anchors.…”

“…We believe that the large variability in TFC‐related change (i.e., large standard errors) was likely responsible for the absence of significant 12‐month group differences. Specifically, individuals with larger TFC‐related declines are also more likely to have advanced disease, and the reliability of PRO scores are adversely affected by cognitive impairment …”

Preliminary development of proxy-rated quality-of-life scales for children and adults with Niemann-Pick type C

“…Due to the neurological effects of NPC on patients, after conducting interviews it was decided that it would be more appropriate to develop all the scales as proxy scales, rather than ones for direct use with the patient as very few people with NPC would be able to answer a QoL questionnaire [25]. From the cyclical process between the IPA analysis and the lifeworld-led theory, a bank of all possible items which were considered to have an effect on an individual’s QoL were noted.…”