This study is the first to examine systematically the burden of FRDA in the UK and Germany, encompassing not only medical resource utilization, but also the burden on respondents in terms of symptoms, the impact on daily activities (including the need for mobility assistance and modifications to accommodation), and the requirement for caregiver support. The impact of caring for people with FRDA was also assessed.
The results show that the annual burden of FRDA is significant and falls on the health and social care sectors, on society due to work loss, on caregivers and on the individuals themselves. While the results of the UK COI study show a mean cost of health care per person of £3,230 per annum (including medications), this does not reflect the true burden of FRDA. When non-health care resource requirements (education, caregiver support etc) are included, the cost significantly rises to an estimated £7,537 per person. When indirect costs such as work loss, mobility aids and accommodation modifications are also taken into consideration, the estimated cost per person rises to between £11,818 and £18,774, depending on whether the costs of long-term unemployment or early retirement due to FRDA are included in the calculation. As direct health care costs represent such a small proportion of total costs, focussing on these and excluding the cost of long-term unemployment, would significantly underestimate the true burden to society. The main benefits of improved treatment options would be felt from a societal perspective should the need for caregiver support be reduced, if people were more able to participate in the workforce and if the need for modifications to living accommodation were reduced.
In terms of resource utilization, 61% of participants visited a neurologist in the UK and in Germany, while 47% and 82% visited a physiotherapist, and 48% and 61% a PCP, (UK and Germany respectively).
In Germany, the proportion of patients admitted to hospital for FRDA in the previous 12 months was twice that in the UK (46% versus 23%). Similarly, the proportion of participants who had had foot surgery at some time was more than double that in the UK (21% versus 9%), while non-prescribed drug use for FRDA-related symptoms was higher in the UK (3.2 versus 1.38 medications). The apparent difference in co-enzyme Q10 use between the two countries is notable with just one German patient taking co-enzyme Q10, compared with 17 (9 prescription and 8 OTC) in the UK. This difference may in part be a consequence of a high dose co-enzyme Q10/vitamin E trial having been conducted in the UK  and may also reflect a bias in the UK sample of patients. In general, patients willing to fill in questionnaires are more willing to participate in research and therefore more active in seeking therapeutic options.
Among the employed participants, mean work-time lost per patient was higher in Germany than in the UK (1.9 versus 1 hour per week), while the proportion of UK caregivers who had had to take time off work was almost twice that of Germany (22% versus 12%).
In interpreting these data, a number of caveats should be considered including the sample size. With 75 UK and 28 German patients taking part in the study, it is not possible to say whether they were representative of the FRDA populations although, considering the rarity of the condition, these sample sizes are considered reasonable.
The differing means of recruitment should also be taken into account. UK respondents could be more highly motivated (since they were known to the patient association and took the time to complete the questionnaire). While this is not a problem in itself, there is potential to introduce bias if these patients were atypical in terms of disease severity or in their ability to access health and social care resources.
Similarly the methodological differences between the two samples should be considered: whereas in the UK respondents were asked to complete PCIFs from memory, in Germany, in addition to the PCIFs completed by the patients, the recruiting physicians collected resource use and diagnostic information on PRFs. No such physician-reported, treatment-related data were collected in the UK study.
While patient recall is likely to be reasonable over the last 3 months, it may be less accurate (especially for routine events) as the recall period increases. Exceptions are major events such as hospitalizations and surgery, where there is evidence to suggest recall is as good over longer periods of time. While the recall periods specified in the questionnaires were designed to reflect this, an element of recall bias cannot be ruled out.
With no comprehensive studies in the literature, direct comparisons are difficult. For this reason we have chosen to compare the mean annual burden of FRDA with that of Parkinson’s disease, one of the most common neurodegenerative conditions and one with similarities in terms of symptoms and progression of the disease .
Findley et al reported a higher mean annual burden for advanced Parkinson’s disease of £28,700 , compared with between £11,818 and £18,774 for FRDA. Of the £28,700, £1,881 could be attributed to direct medical costs, £13,364 to direct non-medical costs and £12,454 to indirect informal care cost. Thirty-nine percent of advanced Parkinson’s disease patients were hospitalized in the previous 12 months, compared with 23% of individuals with FRDA in the UK and 46% in Germany. Parkinson’s disease patients experienced an average of 1.6 admissions and 2.9 consultations per year, while in the UK, individuals with FRDA experienced 2.6 admissions and 14.1 consultations. In terms of direct non-medical resources such as respite care, 13% of Parkinson’s disease patients had used respite care in the previous 12 months, compared with 5% of FRDA responders in the UK and 7% in Germany.
Parkinson’s disease severity is measured using the Hoehn and Yahr (H&Y) scale. All Parkinson’s disease patients, regardless of disease severity, can experience the OFF state. In the OFF state, individuals with Parkinson’s disease can experience tremors, stiffness, slowness of movement and/or periods of immobility. This can be due to medication wearing off, or a reaction to the medication itself, manifesting in a re-emergence of symptoms.
Sixty-eight percent of people with Parkinson’s disease reported in the study by Findley had a (H&Y) score of 3 or 4, spending between 0 and 25% of their waking time in an OFF state (=OFF 1). As expected, disease progression was associated with an increase in carer hours from 5.4 professional and 34 informal carer hours/week for OFF 1, to 21 professional and 51.25 informal care hours/week for OFF IV.
In contrast to Findley’s study, where the average age of individuals with Parkinson’s disease was 71.7 years, the average age of individuals with FRDA was significantly less at 32 years in the UK and 28 in Germany. With more children and young adults in the early to mid-stages of the disease, the cost of care is lower and may well be hidden (with younger parents, individuals with FRDA potentially have access to additional informal unpaid support from relatives, teachers and other caregivers). Given that Parkinson’s disease has a duration of 20 years whereas FRDA has a duration of 40 to 50 years, the cost to society may well be greater than for Parkinson’s disease.
In terms of future work, studies could include validating the PCIF for use in other countries and incorporating the use of the Friedreich’s Ataxia Impact Scale (FAIS) . Data from the FAIS could then be compared to actual costs and burden of care to give an indication of the impact of the disease. Similarly, collecting data on clinical parameters such as the Friedreich’s Ataxia Rating Scale (FARS) may provide an indication of the cost and burden associated with disease severity.