Table 4.

Description of investigations conducted with respect to night/shift work and endometriosis.

Reference	Type of Study	Sample	Results	Considerations
[49]	cross-sectional	1945 female flight attendants and 236 female teachers	There was no difference between the two cohorts, OR a 1.0 (95% CI b 0.5–2.2). Higher incidence of endometriosis in flight attendants with long haul flights than in the lowest quartiles OR 2.2 (95% CI 1.1–4.2) emerged.	In addition to shift work, the greatest exposure to cosmic rays for flight attendants was evaluated.
[50]	case-control	235 women with surgical diagnosis of endometriosis and 545 women controls	Night work was associated with an increase in the incidence of endometriosis OR 1.48 (95% CI 0.96–2.29), in the case of jobs involving more than half of their work time during the night hours OR 1.98 (95% CI 1.01–3.85). High risk of endometriosis emerged mostly for those who worked for 5 consecutive years for more than 50% of the time in night work shifts (OR = 5.32 95% CI 1.21–23.0).	The influence of night work, especially if prolonged, on the incidence of disease was suggested.
[51]	prospective (follow up 16 years)	89,400 women; 2062 women with laparoscopic diagnosis of endometriosis over 16 years of follow-up	There was no correlation between night work and the incidence of endometriosis. In the sub-sample of infertile women, a significance was highlighted for those who had been working at night for more than 5 years, OR 1.71 (95% CI 1.18–2.49).	Women with seniority (nurses) > 5 years, with night shifts, had a greater risk in the case of concomitant situation of infertility.
[10]	case-control	341 women with laparoscopic diagnosis of endometriosis and 742 women controls	Higher incidence of endometriosis reported in flight attendants (OR 9.80, 95% CI 1.08–89.02) serving at service stations (OR 5.77, 95% CI 1.03–32.43), health workers (OR 1.49, 95% CI 1.03– 2.15).	The sample size of the subgroups, divided by work activity, was very small.

^a OR—Odds ratio; ^b CI—confidence interval.