Table 2.

Summary of studies reporting PCF outcomes

Author year	Data source, territory, population	N	Age	PCF outcome data reported
Chabanon 2018 [44]	NatHis-SMA	81	Adults and children	PCF % predicted values, median (IQR):
	Belgium, France, and Germany			•Type 2 SMA, non-sitter (n = 15): 43 (34–62)
	Types 2 and 3 SMA			•Type 2 SMA, sitter (n = 9): 68 (51–79)
				•Type 3 SMA, non-ambulant (n = 9): 88 (67–112)
				•Type 3 SMA, ambulant (n = 10): 79 (70–88)
				•Overall (n = 43): 69 (45–84)
				Patients > 6 years of age performed PCF assessments in the sitting position which were captured with the Vitalograph spirometer; the best results of three measurements were selected for analysis
Kapur 2019 [42]	Children attending the Children’s Health Queensland, Brisbane, Australia Types 1–3 SMA	25	Children	PCF, median L/min (IQR) from a cross-sectional study:
				•Type 2 SMA: 178.8 (246.0)
				•Type 3 SMA: 277.8 (124.8)
				•All patients: 231.9 (181.8)
				Median Z scores lower in patients who needed NIV (results displayed graphically); p = 0.75
				Children who refused to perform a respiratory test were not forced. Standard testing methods were used
Veldhoen 2022 [7]	Patients enrolled in this study were participating in a prospective, population-based prevalence cohort study on SMA in the Netherlands (Wadman 2017, 2018, 2020) Types 1–3 SMA	80	Adults and children	Longitudinal patterns of PCF reported graphically
				•PCF was lowest in Type 1c SMA:<160 L/min throughout life
				•Patients with Type 2 SMA reached 160–270 L/min, with clear differences between Types 2a and 2b SMA
				•Patients with Type 3 SMA had higher PCF values from earlier ages onwards in comparison with Type 2b SMA, but median values were still below normal

Abbreviations: IQR = interquartile range; NatHis = natural history; NIV = non-invasive ventilation; PCF = peak cough flow; SMA = spinal muscular atrophy.