Left lateral decubitus sleeping position is associated with improved gastroesophageal reflux disease symptoms: A systematic review and meta-analysis

Table 1 Baseline characteristics of patients included in the study

Study identifier	Khoury et al[7], 1999	Schuitenmaker et al[8], 2022	Schuitenmaker et al[9], 2022
Study design	Cross-sectional	Cross-sectional	Randomized Controlled Trial
Study location	United States of America	Netherlands	Netherlands
Groups	N/A	N/A	Intervention	Sham
Number of subject	10	57	50	50
Age (yr) mean ± SD/(range)	47.6 (30-67)	48.9 ± 16.1	52.0 ± 12.0	52.5 ± 12.2
Sex ratio (M/F)	7/3	26/31	16/34	21/29
BMI kg/m2, mean ± SD	NR	26.7 ± 4.6	25.1 ± 4.3	26.3 ± 4.1
Smoking N (%)	NR	NR	4 (8)	4 (8)
Disease severity, N (%)	NR	Grade A RE: 10 (17.5); Grade B RE: 11 (19.3); Grade C RE: 2 (3.5); NERD: 16 (29.1); Esophageal hypersensitivity: 9 (16.4); Functional heartburn: 7 (12.7); Unknown: 2 (3.5)	NR	NR
Diaphgramatic hernia, N (%)	NR	32 (56.1) with mean size 3.0 ± 1.3	Total: 32; Yes: 13 (40.6); No: 13 (40.6); Unknown: 6 (18.8)	Total 30; Yes: 13 (43.3); No: 15 (50.0); Unknown: 2 (6.7)
Medication use, N (%)	None	PPI and H2RA: 9 (15.8); PPI: 37 (64.9); H2RA: 1 (1.8); None: 10 (17.5)	PPI: 20 (40); H2RA: 2 (4); Antacids: 33 (66)	PPI: 27 (54); H2RA: 3 (6); Antacids: 27 (54)
GERDQ score, mean ± SD	NR	NR	11.9 ± 2.0	12.2 ± 2.0

GERDQ: GERD questionnaire; H2RA: Histamine 2 receptor antagonist; GERD: Gastroesophageal reflux disease; M/F: Male/Female; N/A: Not applicable; NR: Not reported; PPI: Proton pump inhibitor; RE: Reflux esophagitis; SD: Standard deviation.