Nottingham Hip Fracture Score and Acute Physiology and Chronic Health Evaluation-II: Predicting 30-day mortality in elderly hip fracture

Table 1 Distribution of different variables in studied cases

Statistics (categorical variables)
Name of characteristics (n = 182)	Categories	Numbers	Percentage
Age in year	60-70 years	58	31.9
	71-80 years	80	44.0
	> 80 years	44	24.2
Sex	Female	98	53.8
	Male	84	46.1
Hemoglobin in gm/dL	> 10	95	52.2
	≤ 10	87	47.8
Length of stay in days	< 7	29	15.9
	7-15	132	72.5
	16-30	21	11.5
Malignancy	No	176	96.7
	Yes	6	3.3
Number of comorbidities	< 2	66	36.3
	≥ 2	116	63.7
Admission Mini Mental Test Score	> 6/10	100	54.9
	≤ 6/10	82	45.1
Diagnosis (fracture)	IT left femur	60	33.0
	IT right femur	65	35.7
	Left acetabulum	1	0.5
	NOF left	29	15.9
	NOF right	27	14.8
American Society of Anesthesiologists	II	92	50.5
	III	88	48.4
	IV	2	1.1
H/O organ insufficiency	No	84	46.2
	Yes	98	53.8
Renal failure	No	148	81.3
	Acute renal failure	13	7.1
	Chronic renal failure	21	11.5
Outcome	Survived	166	91.2
	Mortality	16	8.8

IT: Intertrochanteric; NOF: Neck of femur.

Table 2 Comparison of variables between survival and mortality cases

Comparison of continuous variables with outcome
Name of characteristics at admission (n = 182)	Survived (n = 166)		Mortality (n = 16)		P value
	Mean	SD	Mean	SD
Weight	61.44	5.56	61.88	16.78	0.182
Nottingham Hip Fracture Score	5.23	1.10	5.94	0.68	0.004a
Temp (rectal) (°C)	36.64	0.35	36.74	0.36	0.163
Mean arterial pressure	100.47	16.49	110.21	18.71	0.028a
Heart rate/minute	84.01	14.71	93.31	28.29	0.262
Respiratory rate/minute	15.66	2.74	18.38	2.68	< 0.001a
Partial pressure of oxygen	92.99	29.00	96.48	30.85	0.837
PH	7.40	0.05	7.34	0.09	0.002a
Serum Na+ (mEq/L)	130.91	6.63	129.69	8.02	0.498
Serum K+ (mEq/L)	4.08	0.58	4.19	0.80	0.663
Serum creatinine (mg/dL)	1.12	0.62	1.42	0.46	0.003a
Hematocrit (%)	31.11	4.73	30.00	3.95	0.252
Total leukocyte count (total/mm3)	9486.14	3219.32	11243.75	4120.84	0.080
Glasgow Coma Score	14.90	0.45	14.13	1.02	< 0.001a
Acute Physiology and Chronic Health Evaluation-II score	10.11	3.79	16.94	3.26	< 0.001a

^aP < 0.005 is significant.

Table 3 Depicting the sensitivity and specificity of Nottingham Hip Fracture Score and Acute Physiology and Chronic Health Evaluation-II score

Name of characteristics	Area under the curve	95%CI	P value	Sensitivity	Specificity	Cut of value
Nottingham Hip Fracture Score	0.709	0.60-0.81	0.006a	75.00%	61.00%	6
Acute Physiology and Chronic Health Evaluation-II	0.904	0.83-0.97	< 0.001a	87.50%	74.00%	13

^aP value < 0.05 considered significant.

Table 4 Discriminatory abilities of Acute Physiology and Chronic Health Evaluation-II score and Nottingham Hip Fracture Score for secondary outcomes

Outcome	APACHE-II	NHFS	APACHE-II (P value)	NHFS (P value)
Ventilatory support (AUC)	0.838	0.686	0.00264	0.00264
Inotropic support (AUC)	0.751	0.6	0.00063	0.00063
Acute kidney injury (AUC)	0.845	0.698	0.117	0.117
Length of stay (Spearman's P)	0.356	0.207	8.41E-07	0.00513

APACHE-II: Acute Physiology and Chronic Health Evaluation-II; AUC: Area under the curve; NHFS: Nottingham Hip Fracture Score.