Toward the Definition of Patient-Reported Outcome Measurements in Hereditary Spastic Paraplegia

Validation of the Italian version of a patient-reported outcome measure for Hereditary Spastic Paraplegia

BACKGROUND AND AIM

Patient-reported outcome measures (PROMs) are recognized as valuable measures in the clinical setting. In 2018 we developed the Italian version of the "Hereditary Spastic Paraplegia-Self Notion and Perception Questionnaire" (HSP-SNAP), a disease-specific questionnaire that collects personal perception on motor symptoms related to HSP such as stiffness, weakness, imbalance, reduced endurance, fatigue and pain. In this study our primary aim was to assess the questionnaire validity and reliability. Our secondary aim was to characterize the symptoms "perceived" by patients with HSP and compare them with those "perceived" by age-matched healthy subjects.

METHODS

The 12-item HSP-SNAP questionnaire was submitted to 20 external judges for comprehensibility and to 15 external judges for content validity assessment. We recruited 40 subjects with HSP and asked them to fill the questionnaire twice for test-retest procedure. They also completed the Medical Outcome Survey Short Form (SF-36) and were evaluated by the Spastic Paraplegia Rating Scale and the Six-Minute Walk Test. We also recruited 44 healthy subjects who completed the HSP-SNAP once to test score variability.

RESULTS

The HSP-SNAP content validity index was high (0.8±0.1) and the test-retest analysis showed high reliability (ICC = 0.94). The mean HSP-SNAP score (score range 0-48) of the HSP group was 22.2±7.8, which was significantly lower than healthy subjects (43.1±6.3). The most commonly perceived symptom was stiffness, followed by weakness and imbalance.

CONCLUSION

Although HSP-SNAP does not investigate non-motor symptoms and we validated only its Italian version, it showed good validity and reliability and it could be used in combination with other objective outcome measures for clinical purposes or as endpoints for future clinical rehabilitation studies.

TRIAL REGISTRATION

Trial Registration: ClinicalTrial.gov, NCT04256681. Registered 3 February 2020.

Development and validation of TreatHSP-QoL: a patient-reported outcome measure for health-related quality of life in hereditary spastic paraplegia

BACKGROUND

Hereditary spastic paraplegia (HSP) is a rare neurodegenerative disease that lacks specific and validated patient-centered outcome measures (PCOMs). We aimed to develop and validate a health-related quality of life (HRQoL) questionnaire specific to HSP ("TreatHSP-QoL") that could be used as a PCOM.

RESULTS

The pilot-items of the TreatHSP-QoL (45 five-level Likert scale items, with values per item between 0 and 4) were developed based on a qualitative data analysis of 54 semi-structured interviews, conducted in person with 36 HSP patients and 18 caregivers. It was then reduced and modified through the validation process to 25 items. The main validation was performed using the online questionnaire in 242 HSP patients and 56 caregivers. The exploratory factor analysis defined five subdomains. Cronbach's alpha ranged from 0.57 to 0.85 for the subdomains and reached 0.85 for the total score. The test-retest Pearson correlation reached 0.86 (95% Confidence Interval (CI) [0.79, 0.91]). Pearson correlations with the EuroQol-5 Dimension (5 levels) (EQ-5D-5L) and Friedreich Ataxia Rating Scale-Activities of Daily Living (FARS-ADL) questionnaires varied strongly among the subdomains, with the total scores reaching 0.53 (95% CI [0.42, 0.61]) and -0.45 (95% CI [- 0.55, - 0.35]), respectively. The caregiver-patient response Pearson correlation ranged between 0.64 and 0.82 for subdomains and reached 0.65 (95% CI [0.38, 0.81]) for the total score.

CONCLUSIONS

TreatHSP-QoL can be used in high-quality clinical trials and clinical practice as a disease-specific PCOM (i.e., HRQoL measure) and is also applicable as a proxy questionnaire. Score values between 0 and 100 can be reached, where higher value represents better HRQoL. The Pearson correlations to the EQ-5D-5L and FARS-ADL support the additional value and need of HSP-specific PCOM, while non-specific QoL-assessment and specific clinical self-assessment tools already exist. All in all, the results demonstrate good validity and reliability for this new patient-centered questionnaire for HSP.

Long-term progression of clinician-reported and gait performance outcomes in hereditary spastic paraplegias

Introduction

Hereditary spastic paraplegias (HSPs) are a heterogeneous group of neurodegenerative diseases in which little is known about the most appropriate clinical outcome assessments (COAs) to capture disease progression. The objective of this study was to prospectively determine disease progression after 4.5 years of follow-up with different clinician-reported (ClinRO) and gait performance outcomes (PerFOs).

Methods

Twenty-six HSP patients (15 SPG4, 5 SPG7, 4 SPG5, 2 SPG3A) participated in this single-center cohort study in which the ClinRO: Spastic Paraplegia Rating Scale; and the PerFOs: 10-meters walking test and timed-up and go (TUG), at self-selected and maximal walking speeds; Locomotor Rehabilitation Index; and 6-min walking test were performed at baseline and after 1.5 (18 patients) and 4.5 (13 patients) years.

Results

In the 3-year interval between the second and third assessments, significant progressions were only found in PerFOs, while in the overall 4.5 years of follow-up, both PerFOs and ClinROs presented significant progressions. The progression slopes of COAs modeled according to the disease duration allowed the estimation of the annual progression of the outcomes and sample size estimations for future clinical trials of interventions with different effect sizes. TUG at maximal walking speed was the only COA capable of differentiating subjects with a worse compared to a stable/better impression of change and would require the smallest sample size if chosen as the primary endpoint of a clinical trial.

Discussion

These findings indicate that both performance and clinician-reported outcomes can capture long-term progression of HSPs, with some PerFOs presenting greater sensitivity to change. The presented data are paramount for planning future disease-modifying and symptomatic therapy trials for this currently untreatable group of diseases.

Outcome Measures and Biomarkers for Clinical Trials in Hereditary Spastic Paraplegia: A Scoping Review

Hereditary spastic paraplegia (HSP) is characterized by progressive lower limb spasticity. There is no disease-modifying treatment currently available. Therefore, standardized, validated outcome measures to facilitate clinical trials are urgently needed. We performed a scoping review of outcome measures and biomarkers for HSP to provide recommendations for future studies and identify areas for further research. We searched Embase, Medline, Scopus, Web of Science, and the Central Cochrane database. Seventy studies met the inclusion criteria, and eighty-three outcome measures were identified. The Spastic Paraplegia Rating Scale (SPRS) was the most widely used (27 studies), followed by the modified Ashworth Scale (18 studies) and magnetic resonance imaging (17 studies). Patient-reported outcome measures (PROMs) were infrequently used to assess treatment outcomes (28% of interventional studies). Diffusion tensor imaging, gait analysis and neurofilament light chain levels were the most promising biomarkers in terms of being able to differentiate patients from controls and correlate with clinical disease severity. Overall, we found variability and inconsistencies in use of outcome measures with a paucity of longitudinal data. We highlight the need for (1) a standardized set of core outcome measures, (2) validation of existing biomarkers, and (3) inclusion of PROMs in HSP clinical trials.