. Author manuscript; available in PMC: 2017 Jul 1.

Published in final edited form as: Am J Ind Med. 2016 May 17;59(7):532–537. doi: 10.1002/ajim.22608

TABLE IV.

ALS Mortality by Employment Duration and Time Since First Employment Among US Flight Attendants, 1960–2007

	Obs	Exp	SMR (95%CI)
Employment duration, years^a
<5	4	1.48	2.70 (0.73–6.90)
5–<15	2	1.28	1.56 (0.19–5.63)
15+	3	1.30	2.30 (0.48–6.73)
Time since first employment, years^a
<30	0	1.15	0.00 (0.00–3.21)
30–<40	3	1.60	1.88 (0.39–5.49)
40–<50	3	0.99	3.04 (0.63–8.88)
50+	3	0.34	8.87 (1.83–25.92)

ALS, amyotrophic lateral sclerosis; Obs, observed number of ALS deaths based on underlying cause; Exp, expected number of ALS deaths based on US referent rates; SMR, standardized mortality ratio; CI, confidence interval.

Based on employment as a flight attendant at Pan Am and National excluding training and adjusted for part-time work.