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

Published in final edited form as: J Am Geriatr Soc. 2016 Jun 28;64(8):1656–1661. doi: 10.1111/jgs.14256

Table 3.

Associations between hospital characteristics and study outcomes among 458,526 Medicare beneficiaries with hip fracture

	Received surgery > 48h after admission		Readmission/death at 30 days		Death at 30 days		Readmission at 30 days

	Adjusted OR (95% CI)	P	Adjusted OR^a (95% CI)	P	Adjusted OR^a (95% CI)	P	Adjusted OR^a (95% CI)	P
Teaching status^b
Non-teaching	Reference		Reference		Reference		Reference
Minor teaching	1.11 (1.02,1.2)	0.012	1.02 (1,1.05)	0.074	0.97 (0.93,1.0)	0.066	1.05 (1.02,1.08)	0.003
Major teaching	1.71 (1.5, 1.96)	<0.001	1.15 (1.1,1.2)	<0.001	1 (0.94,1.07)	0.971	1.2 (1.13,1.26)	<0.001
Nurse-bed ratio^c	0.97 (0.95,1.0)	0.058	0.98 (0.97,0.99)	<0.001	0.99 (0.98,1)	0.207	0.98 (0.96,0.99)	<0.001
Nurse skill mix^d	0.84 (0.69,1.02)	0.085	0.88 (0.8,0.96)	0.007	0.9 (0.78,1.04)	0.153	0.88 (0.8,0.97)	0.008
Advanced technology present^e	0.87 (0.81,0.93)	0.856	0.97 (0.95,1)	0.050	1.01 (0.97,1.04)	0.678	0.96 (0.93,0.98)	0.003
Facility size
< 200 beds	Reference		Reference		Reference		Reference
200-399 beds	1.33 (1.22,1.44)	<0.001	1.05 (1.02,1.08)	<0.001	0.98 (0.94,1.02)	0.309	1.08 (1.04,1.12)	<0.001
>399 beds	1.5 (1.36,1.66)	<0.001	1.05 (1.01,1.09)	0.012	0.98 (0.93,1.02)	0.301	1.08 (1.03,1.12)	0.001
Case volume
Quartile 1 (≤12)	Reference		Reference		Reference		Reference
Quartile 2 (13-73)	0.89 (0.81,0.97)	0.009	0.93 (0.88,0.98)	0.009	0.88 (0.82,0.95)	0.001	0.99 (0.93,1.05)	0.764
Quartile 3 (74-175)	0.77 (0.7,0.84)	<0.001	0.91 (0.86,0.96)	<0.001	0.86 (0.8,0.93)	<0.001	0.97 (0.91,1.03)	0.331
Quartile 4 (>175)	0.61 (0.55,0.68)	<0.001	0.87 (0.83,0.92)	<0.001	0.83 (0.77,0.9)	<0.001	0.94 (0.89,1)	0.070

Notes:

Regression models adjusted for age; sex; race (black, white, other); fracture location (femoral neck, intertrochanteric, subtrochanteric, multiple locations); surgery type (internal fixation, hemiarthroplasty, total hip arthroplasty); nursing home residence; and 17 comorbidities (Alzheimer's disease, angina, cancer, congestive heart failure, chronic lung disease, diabetes, hypertension, liver disease, electrolyte Disturbance, paraplegia, pathological fracture, arrhythmias, pulmonary fibrosis, renal failure, unstable angina, valvular abnormalities, weight loss)

Non-teaching: resident-to-bed ratio = 0; minor teaching: resident-to-bed ratio above 0 but below 0.25; major teaching: resident-to-bed ratio ≥ 0.25

Nurse-to-bed ratio calculated as full-time employee nurses divided by total number of hospital beds

Nurse skill mix calculated as total number of full-time-employee registered nurses and licensed practical nurses divided by total number of full-time employee nurses

Advanced technological capabilities determined to be present if a hospital had capacity to perform open heart surgery or organ transplantation, or had a burn unit. OR: Odds ratio; CI: confidence interval.