. Author manuscript; available in PMC: 2015 May 23.

Published in final edited form as: Muscle Nerve. 2011 May 23;44(1):20–24. doi: 10.1002/mus.22114

Table 4.

Final proportional hazards model for survival in all 427 ALS subjects.

	Hazard ratio	95% CI	P-value
Age	1.03	(1.01–1.05)	0.0009
Cardiovascular history	2.27	(1.39–3.69)	0.0009
Time from symptom onset	0.99	(0.99–0.99)	0.0001
BMI	0.86	(0.80–0.93)	0.0001
BMI²	1.001	(1.000–1.001)	0.02
FVC	0.97	(0.96–0.98)	0.000007

Age, BMI (body mass index), FVC (forced vital capacity), and time since symptom onset are included as continuous variables, whereas cardiovascular disease history is dichotomous. Hazard ratios were calculated using a Cox proportional hazards model with stepwise selection. Interpreting the results, subjects with a reported history of cardiovascular disease were twice as likely to die during the study, whereas there was a 14% reduction in the risk of death during the study with each increasing unit of BMI, with a reduction in survival at the highest levels of BMI.