Table 3.

of Influenza Hospitalization Versus None on the Occurrence of Hip Fracture Hospitalizations Among U.S. Long-stay Nursing Home Residents ≥65 years old Under a Series of Models, 2000–2009

Model			Incidence Rate Ratioa (95% CI)
	N b (facility)	N b (facility by week)	Unadjusted	Adjusted	Fixed-Effects
Influenza hospitalizations	454	208,412	1.12 (1.08–1.18)	1.13 (1.08–1.17)	1.13 (1.08–1.18)
City-wide influenza mortality	454	195,653c	1.03 (1.01–1.04)	1.02 (1.01–1.03)	1.00 (0.99–1.02)
Influenza vaccination rate ≥ 65%	454	208,412	0.98 (0.93–1.04)	0.98 (0.92–1.04)	0.99 (0.92–1.06)

^a Note: Interpretable as a relative change (ie, 1.2, 20%).

^bSample used in adjusted analysis

^cCity-wide influenza death rate was missing for 6% of sample.

Covariate adjusted includes: Year fixed effects, resident gender, age, facility antibiotic use, influenza vaccination, percent of residents with rehabilitation, ostomy, or dialysis care, the percent of residents diagnosed with depression and dementia, and the no of nursing FTE per 100 residents.

Fixed effects includes fixed effect terms for each year and facility without adjustment for any specific covariate.