Autonomic function characteristics and stratification analysis of adolescent patients with depressive disorders based on the low-frequency:high-frequency ratio

Table 3 Variable assignment methods for multiple linear regression

Project	Value assignment method
Gender	Male = 1, female = 2
Medical-seeking status	Initial onset = 1, recurrent episodes = 2
Place of residence	Urban area = 1, town = 2, rural area = 3
Payment method	Out-of-pocket expense = 1, medical insurance = 2
Per capita monthly household income (yuan)	< 3000 = 1, 3000-8000 = 2, > 8000 = 3
Caregiver status	Parents = 1, single parent (mother) = 2, single parent (father) = 3
Family relationships	Intimate = 1, neutral = 2, distant = 3
Adverse experiences	No = 1, yes = 2
Body mass index (kg/m2)	18.5-23.9 = 1, < 18.5 = 2, 24.0-27.9 = 3, ≥ 28.0 = 4
SAS scores	< 50 = 1, 50-59 = 2, 60-69 = 3, ≥ 70 = 4
SDS scores	< 53 = 1, 53-62 = 2, 63-72 = 3, ≥ 73 = 4
LF:HF ratio (autonomic bias)	1.0-2.0 (normal autonomic function) = 1, > 2.0 (severely sympathetic autonomic function) = 2, < 1.0 = 3 (severely parasympathetic autonomic function)
Disease duration factors (years)	Original value carryover

SDS: Self-rating Depression Scale; SAS: Self-rating Anxiety Scale; LF:HF: Low-frequency:high-frequency.