J Curr Surg

Journal of Current Surgery, ISSN 1927-1298 print, 1927-1301 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Curr Surg and Elmer Press Inc

Journal website http://www.currentsurgery.org

Original Article

Volume 6, Number 1, March 2016, pages 21-29

Length of Hospitalization: A Protective Factor in a Prospective Observational Cohort Study in Brazilian ASA III and IV Hip Fracture Elderly Patients

Figure 1. Survival time analyzed by Kaplan-Meier curves. (A) Analysis to all subjects. The survival time was 263.88 ± 8.94 days (64.28%) (left graph). The hazard cumulative risk to all subjects was 44.17% (right graph). (B) Analysis only for operated subjects. The survival time was 316.82 ± 7.66 days (79.75%) (left graph). The hazard cumulative risk to operated subjects was 22.62% (right graph). (C) Analysis only for non-operated subjects. The survival time was 134.45 ± 17.64 days (26.50%) (left graph). The hazard cumulative risk to non-operated subjects was 132.77% (right graph).

Figure 2. Comparison in the survival time for all subjects. (A) Comparing the survival time between ASA scores (ASA III and ASA IV), a difference was observed by the log rank test (Mantel-Cox) (P < 0.001). Left side: survival function graph. ASA III 289.09 ± 8.91 days (95% CI: 271.62 - 306.56) (71.44%) and ASA IV 147.78 ± 22.56 days (95% CI: 103.57 - 192) (31.37%). Right side: hazard function graph indicating the cumulative risk after 1 year (33.63% for ASA III and 115.92% for ASA IV). (B) Comparing the survival time between status surgery (surgery or no surgery), a difference was observed by the log rank test (Mantel-Cox) (P < 0.001). Left side: survival function graph. Surgery 316.83 ± 7.66 days (95% CI: 301.82 - 331.83) (79.75%) and no surgery 134.46 ± 17.64 days (95% CI: 99.89 - 169.03) (26.51%). Right side: hazard function graph indicating the cumulative risk after 1 year (22.62% for surgery and 132.78% for no surgery).

**Table 1.** Population Characteristics
Characteristics	General	Surgical group	Non-surgical group
IQR: interquartile range. Significant difference between groups (P ≤ 0.05). *Asthma, chronic obstructive pulmonary disease and chronic renal failure.
Gender age (years) (mean (SD), median (IQR))
Female	82 (7), 83 (77 - 87)	82 (6.9), 82 (77 - 86)*	83 (7.2), 84 (78 - 87)
Male	80 (7.9), 81 (75 - 86)	79 (7.1), 78 (75 - 84)*	84 (8.9), 85 (80 - 89)
Fracture age (years) (mean (SD), median (IQR))
Transtrochanteric fracture	82 (7), 83 (78 - 87)	82 (6.9), 82 (78 - 87)	83 (7.2), 84 (79 - 87)
Neck fracture	81 (7.4), 81 (76 - 85)	80 (6.8), 80 (75 - 84)	83 (8.6), 84 (77 - 87)
Subtrochanteric fracture	82 (9.5), 86 (70 - 89)	81 (10), 86 (70 - 89)	88 (-), 88 (-)
ASA age (years) (mean (SD), median (IQR))
ASA III	81 (7.2), 82 (77 - 86)	81 (6.9), 81 (76 - 86)*	84 (7.9), 84 (79 - 89)
ASA IV	83 (7.5), 85 (78 - 88)	85 (7.7), 87 (80 - 92)*	83 (7.4), 85 (78 - 86)
Length of hospitalization (days) (mean (SD), median (IQR))	12.66 (10.63), 10 (6 - 15)	12.7 (9.5), 10 (7 - 15)	12.57 (13.1), 9 (4 - 15)
Comorbidity (n, %)
Yes	267 (93.4)	189 (93.1)	78 (94)
No	19 (6.6)	14 (6.9)	5 (6)
Comorbidity (n, %)
Systemic arterial hypertension	180 (62.9)	132 (65)	48 (57.8)
Ischemic stroke	64 (22.4)	19 (9.4)	45 (54.2)
Ischemic heart disease	88 (30.8)	56 (27.6)	32 (38.6)
Diabetes	51 (17.8)	31 (15.3)	20 (24.1)
Others**	55 (19.2)	35 (17.2)	20 (24.1)

Table 1. Population Characteristics

Characteristics

General

Surgical group

Non-surgical group

IQR: interquartile range. *Significant difference between groups (P ≤ 0.05). **Asthma, chronic obstructive pulmonary disease and chronic renal failure.

Gender age (years) (mean (SD), median (IQR))

Female

82 (7), 83 (77 - 87)

82 (6.9), 82 (77 - 86)*

83 (7.2), 84 (78 - 87)

Male

80 (7.9), 81 (75 - 86)

79 (7.1), 78 (75 - 84)*

84 (8.9), 85 (80 - 89)

Fracture age (years) (mean (SD), median (IQR))

Transtrochanteric fracture

82 (7), 83 (78 - 87)

82 (6.9), 82 (78 - 87)

83 (7.2), 84 (79 - 87)

Neck fracture

81 (7.4), 81 (76 - 85)

80 (6.8), 80 (75 - 84)

83 (8.6), 84 (77 - 87)

Subtrochanteric fracture

82 (9.5), 86 (70 - 89)

81 (10), 86 (70 - 89)

88 (-), 88 (-)

ASA age (years) (mean (SD), median (IQR))

ASA III

81 (7.2), 82 (77 - 86)

81 (6.9), 81 (76 - 86)*

84 (7.9), 84 (79 - 89)

ASA IV

83 (7.5), 85 (78 - 88)

85 (7.7), 87 (80 - 92)*

83 (7.4), 85 (78 - 86)

Length of hospitalization (days) (mean (SD), median (IQR))

12.66 (10.63), 10 (6 - 15)

12.7 (9.5), 10 (7 - 15)

12.57 (13.1), 9 (4 - 15)

Comorbidity (n, %)

Yes

267 (93.4)

189 (93.1)

78 (94)

19 (6.6)

14 (6.9)

5 (6)

Comorbidity (n, %)

Systemic arterial hypertension

180 (62.9)

132 (65)

48 (57.8)

Ischemic stroke

64 (22.4)

19 (9.4)

45 (54.2)

Ischemic heart disease

88 (30.8)

56 (27.6)

32 (38.6)

Diabetes

51 (17.8)

31 (15.3)

20 (24.1)

Others**

55 (19.2)

35 (17.2)

20 (24.1)

**Table 2.** One-Year Mortality Predictors to All Subjects
Covariates	Crude HR (95% CI)	Crude P value	Adjusted HR (95% CI)	Adjusted P value
CI: confidence interval; HR: hazard ratio. *Asthma, chronic obstructive pulmonary disease and chronic renal failure.
Age	1.053 (1.025 - 1.082)	≤ 0.001	1.029 (1.004 - 1.055)	0.024
Gender
Female	Reference
Male	1.222 (0.798 - 1.872)	0.355	Refuted	Refuted
ASA score
III	Reference
IV	3.627 (2.401 - 5.478)	≤ 0.001	1.425 (0.895 - 2.268)	0.136
Surgery (yes/no)	6.497 (4.349 - 9.704)	≤ 0.001	6.031 (4.008 - 9.073)	≤ 0.001
Comorbidity (yes/no)	1.166 (0.511 - 2.659)	0.716	Refuted	Refuted
Comorbidity
Systemic arterial hypertension	0.694 (0.469 - 1.028)	0.68	Refuted	Refuted
Ischemic stroke	2.414 (1.607 - 3.625)	≤ 0.001	1.246 (0.612 - 2.536)	0.544
Ischemic heart disease	1.432 (0.958 - 2.139)	0.08	Refuted	Refuted
Diabetes	1.363 (0.850 - 2.185)	0.198	Refuted	Refuted
Others*	1.183 (0.732 - 1.912)	0.493	Refuted	Refuted
Length of hospitalization	0.999 (0.981 - 1.018)	0.922	Refuted	Refuted
Fracture
Trochanteric	Reference		Refuted	Refuted
Neck	0.608 (0.221 - 1.674)	0.608	Refuted	Refuted
Subtrochanteric	0.632 (0.226 - 1.769)	0.632	Refuted	Refuted

Table 2. One-Year Mortality Predictors to All Subjects

Covariates

Crude HR (95% CI)

Crude P value

Adjusted HR (95% CI)

Adjusted P value

CI: confidence interval; HR: hazard ratio. *Asthma, chronic obstructive pulmonary disease and chronic renal failure.

Age

1.053 (1.025 - 1.082)

≤ 0.001

1.029 (1.004 - 1.055)

0.024

Gender

Female

Reference

Male

1.222 (0.798 - 1.872)

0.355

Refuted

ASA score

III

Reference

3.627 (2.401 - 5.478)

≤ 0.001

1.425 (0.895 - 2.268)

0.136

Surgery (yes/no)

6.497 (4.349 - 9.704)

≤ 0.001

6.031 (4.008 - 9.073)

≤ 0.001

Comorbidity (yes/no)

1.166 (0.511 - 2.659)

0.716

Refuted

Comorbidity

Systemic arterial hypertension

0.694 (0.469 - 1.028)

0.68

Refuted

Ischemic stroke

2.414 (1.607 - 3.625)

≤ 0.001

1.246 (0.612 - 2.536)

0.544

Ischemic heart disease

1.432 (0.958 - 2.139)

0.08

Refuted

Diabetes

1.363 (0.850 - 2.185)

0.198

Refuted

Others*

1.183 (0.732 - 1.912)

0.493

Refuted

Length of hospitalization

0.999 (0.981 - 1.018)

0.922

Refuted

Fracture

Trochanteric

Reference

Refuted

Neck

0.608 (0.221 - 1.674)

0.608

Refuted

Subtrochanteric

0.632 (0.226 - 1.769)

0.632

Refuted

**Table 3.** One-Year Mortality Predictors for Operated Subjects
Covariates	Crude HR (95% CI)	Crude P value	Adjusted HR (95% CI)	Adjusted P value
CI: confidence interval; HR: hazard ratio. *Asthma, chronic obstructive pulmonary disease and chronic renal failure.
Age	1.049 (1.002 - 1.098)	0.041	1.054 (1.005 - 1.105)	0.031
Gender
Female	Reference
Male	1.162 (0.593 - 2.276)	0.663	Refuted	Refuted
ASA grade
III	Reference
IV	3.608 (1.516 - 8.587)	0.04	3.236 (1.331 - 7.867)	0.010
Comorbidity (yes/no)	0.954 (0.294 - 3.089)	0.937	Refuted	Refuted
Comorbidity
Systemic arterial hypertension	0.919 (0.487 - 1.735)	0.795	Refuted	Refuted
Ischemic stroke	1.014 (0.362 - 2.846)	0.978	Refuted	Refuted
Ischemic heart disease	1.612 (0.854 - 3.044)	0.141	Refuted	Refuted
Diabetes	1.662 (0.793 - 3.482)	0.178	Refuted	Refuted
Others*	0.651 (0.256 - 1.659)	0.369	Refuted	Refuted
Length of hospitalization	1.029 (1.009 - 1.050)	0.004	1.036 (1.016 - 1.057)	≤ 0.001
Fracture
Trochanteric	Reference		Refuted	Refuted
Neck	0.326 (0.097 - 1.095)	0.070	Refuted	Refuted
Subtrochanteric	0.420 (0.123 - 1.433)	0.166	Refuted	Refuted

Table 3. One-Year Mortality Predictors for Operated Subjects

Covariates

Crude HR (95% CI)

Crude P value

Adjusted HR (95% CI)

Adjusted P value

CI: confidence interval; HR: hazard ratio. *Asthma, chronic obstructive pulmonary disease and chronic renal failure.

Age

1.049 (1.002 - 1.098)

0.041

1.054 (1.005 - 1.105)

0.031

Gender

Female

Reference

Male

1.162 (0.593 - 2.276)

0.663

Refuted

ASA grade

III

Reference

3.608 (1.516 - 8.587)

0.04

3.236 (1.331 - 7.867)

0.010

Comorbidity (yes/no)

0.954 (0.294 - 3.089)

0.937

Refuted

Comorbidity

Systemic arterial hypertension

0.919 (0.487 - 1.735)

0.795

Refuted

Ischemic stroke

1.014 (0.362 - 2.846)

0.978

Refuted

Ischemic heart disease

1.612 (0.854 - 3.044)

0.141

Refuted

Diabetes

1.662 (0.793 - 3.482)

0.178

Refuted

Others*

0.651 (0.256 - 1.659)

0.369

Refuted

Length of hospitalization

1.029 (1.009 - 1.050)

0.004

1.036 (1.016 - 1.057)

≤ 0.001

Fracture

Trochanteric

Reference

Refuted

Neck

0.326 (0.097 - 1.095)

0.070

Refuted

Subtrochanteric

0.420 (0.123 - 1.433)

0.166

Refuted

**Table 4.** One-Year Mortality Predictors for Non-Operated Subjects
Covariates	Crude HR (95% CI)	Crude P value	Adjusted HR (95% CI)	Adjusted P value
CI: confidence interval; HR: hazard ratio. *Asthma, chronic obstructive pulmonary disease and chronic renal failure.
Age	1.020 (0.990 - 1.051)	0.199	Refuted	Refuted
Gender
Female	Reference
Male	1.525 (0.878 - 2.651)	0.134	Refuted	Refuted
ASA grade
Group one	Reference
Group two	1.042 (0.630 - 1.723)	0.873	Refuted	Refuted
Comorbidity (yes/no)	1.259 (0.394 - 4.022)	0.698	Refuted	Refuted
Comorbidity
Systemic arterial hypertension	0.554 (0.333 - 0.920)	0.023	0.645 (0.386 - 1.079)	0.095
Ischemic stroke	0.881 (0.532 - 1.457)	0.621	Refuted	Refuted
Ischemic heart disease	0893 (0.532 - 1.499)	0.667	Refuted	Refuted
Diabetes	0.793 (0.429 - 1.465)	0.459	Refuted	Refuted
Others*	1.420 (0.801 - 2.518)	0.230	Refuted	Refuted
Length of hospitalization	0.968 (0.944 - 0.992)	0.010	0.971 (0.496 - 0.996)	0.023
Fracture
Trochanteric	Reference		Refuted	Refuted
Neck	0.625 (0.085 - 4.607)	0.645	Refuted	Refuted
Subtrochanteric	0.536 (0.071 - 4.017)	0.544	Refuted	Refuted

Table 4. One-Year Mortality Predictors for Non-Operated Subjects

Covariates

Crude HR (95% CI)

Crude P value

Adjusted HR (95% CI)

Adjusted P value

CI: confidence interval; HR: hazard ratio. *Asthma, chronic obstructive pulmonary disease and chronic renal failure.

Age

1.020 (0.990 - 1.051)

0.199

Refuted

Gender

Female

Reference

Male

1.525 (0.878 - 2.651)

0.134

Refuted

ASA grade

Group one

Reference

Group two

1.042 (0.630 - 1.723)

0.873

Refuted

Comorbidity (yes/no)

1.259 (0.394 - 4.022)

0.698

Refuted

Comorbidity

Systemic arterial hypertension

0.554 (0.333 - 0.920)

0.023

0.645 (0.386 - 1.079)

0.095

Ischemic stroke

0.881 (0.532 - 1.457)

0.621

Refuted

Ischemic heart disease

0893 (0.532 - 1.499)

0.667

Refuted

Diabetes

0.793 (0.429 - 1.465)

0.459

Refuted

Others*

1.420 (0.801 - 2.518)

0.230

Refuted

Length of hospitalization

0.968 (0.944 - 0.992)

0.010

0.971 (0.496 - 0.996)

0.023

Fracture

Trochanteric

Reference

Refuted

Neck

0.625 (0.085 - 4.607)

0.645

Refuted

Subtrochanteric

0.536 (0.071 - 4.017)

0.544

Refuted