Identification of the most relevant aspects of spinal muscular atrophy (SMA) with impact on the quality of life of SMA patients and their caregivers: the PROfuture project, a qualitative study

Abstract Background SMA is a hereditary neuromuscular disease that causes progressive muscle weakness and atrophy. Several studies have shown that the burden of SMA is very high at many levels. Functional assessment tools currently used do not completely address the impact of the disease in patients’ life. The objective of this qualitative study was to identify aspects of SMA that are relevant to patients and to design items useful for assessment purposes. Results Five focus group sessions were run during an annual SMA families meeting in Madrid, Spain. Focus groups were composed by parents of SMA type I children, sitter children type II-III, parents of sitter children type II-III, adult patients, and parents of walker children. Two trained facilitators conducted the focus groups using a semi-structured guideline to cover previously agreed topics based on the input of a Scientific and Patient Advisory Committee. The guideline was adapted for the different groups. According to what was communicated by participants, SMA entails a high burden of disease for both patients and their parents. Burden was perceived in physical, psychological, and social areas. Patient’s physical domain was the most relevant for participants, especially for parents of non-ambulant children, followed by limitations of motor scales to capture all changes, parents psychological burden, treatment expectations and patient’s psychological burden. Ten domains were the main areas identified as impacted by the disease: mobility and independence, fatigue and fatigability, infections and hospital consultations, scoliosis and contractures, vulnerability, pain, feeding, time spent in care, breathing, and sleep and rest. Conclusions This study confirms the necessity of evaluating other aspects of the disease that are not assessed in the functional motor scale. Measures of other aspects of the disease, such as pain, fatigue, feeding, should be also considered. A patient-reported outcomes instrument measuring such aspects in a valid and reliable way would be very useful. This study generated a list of new items relevant to be systematically measured in the assessment of the impact of SMA on the patients’ everyday life

Validation of a Set of Instruments to Assess Patient- and Caregiver-Oriented Measurements in Spinal Muscular Atrophy: Results of the SMA-TOOL Study.

Outcome measures traditionally used in spinal muscular atrophy (SMA) clinical trials are inadequate to assess the full range of disease severity. The aim of this study was to assess the psychometric properties of a set of existing questionnaires and new items, gathering information on the impact of SMA from the patient and caregiver perspectives. This was a multicenter, prospective, noninterventional study including patients with a confirmed diagnosis of 5q-autosomal-recessive SMA aged 8 years and above, or their parents (if aged between 2 and 8 years). The set of outcome measurements included the SMA Independence Scale (SMAIS) patient and caregiver versions, the Neuro-QoL Fatigue Computer Adaptive Test (CAT), the Neuro-QoL Pain Short Form-Pediatric Pain, the PROMIS adult Pain Interference CAT, and new items developed by Fundación Atrofia Muscular España: perceived fatigability, breathing and voice, sleep and rest, and vulnerability. Reliability, construct validity, discriminant validity, and sensitivity to change (4 months from baseline) were measured. A total of 113 patients were included (59.3% 2-17 years old, 59.3% male, and 50.4% with SMA type II). Patients required moderate assistance [mean patient and caregiver SMAIS (SD) scores were 31.1 (12.8) and 7.6 (11.1), respectively]. Perceived fatigability was the most impacted domain, followed by vulnerability. Cronbach's alpha coefficient for perceived fatigability, breathing and voice, and vulnerability total scores were 0.92, 0.88, and 0.85, respectively. The exploratory factor analysis identified the main factors considered in the design, except in the sleep and rest domain. All questionnaires were able to discriminate between the Clinical Global Impression-Severity scores and SMA types. Sensitivity to change was only found for the SMAIS caregiver version and vulnerability items. This set of outcome measures showed adequate reliability, construct validity, and discriminant validity and may constitute a valuable option to measure symptom severity in patients with SMA