Table 1.

Characteristics of the study population

Demographics	Study population N = 174
Age at start of ERT, median (range)	50 (24–76)
Age at diagnosis, median (range)	37 (1–66)
Female gender, no. (%)	93 (53)
Country of residence, no. (%)
Netherlands	64 (37)
Germany	36 (21)
US	39 (22)
UK	16 (9)
Other	19 (11)
Clinical characteristics
Disease duration, median (range)	12 (1–33)
Use of wheelchair at start of ERT, no. (%)	90 (52)
Respiratory support at start of ERT, no. (%)*	84 (48)
Follow-up during study
Total follow-up time, median (range)	7 (1–10)
Pre-treatment period, median (range)	4 (0.5–8)
Treatment period, median (range)	4 (0.5–8)

Age, disease duration and follow-up time are expressed in years as median (range). Categorical variables are expressed as number (no.) and percentage (%);

*‘Respiratory support’ includes partial and fulltime, invasive and non-invasive respiratory support