Table 2.

Measures of the association between shift work and possible sleep apnea syndrome used in five studies

First author (year), country	Sex	Comparison	RR	95% CI (low)	95% CI (high)	Source
1. Walia (2012), USA	Men and women combined	AHI ≥ 15 vs. AHI < 15	1.03	0.92	1.15	Table 1 p.545 calculation
2. Yazdi (2014), Iran	Men only	Berlin questionnaire ≥ 2 categories positive vs. < 2 categories positive	0.86	0.44	1.67	Table 2 p.3 calculation
3. Soylu (2014), Turkey	Men and women combined	AHI ≥ 5 vs. AHI < 5	2.15	0.28	16.20	Table 4 p.108 calculation
4. Seyedmehdi (2016), Iran	Men and women combined	Berlin questionnaire ≥ 2 categories positive vs. < 2 categories positive	0.73	0.43	1.25	Table 3 p.769
5. Guclu (2019), Turkey	Men and women combined	Berlin questionnaire ≥ 2 categories positive vs. < 2 categories positive	1.48	0.99	2.22	Table 1 p.50, Table 4 p.52 calculation

RR risk ratio