Effect of Wearing Medical Masks on Perioperative Respiratory Complications in Older Adults with Hip Fracture: A Retrospective Cohort Study

Figures & data

Table 1 Comparisons of Patient Demographics and Comorbidities Between Two Groups

	Total	Observation	Control	χ^2/t	P
Age, mean ± SD (years)	79.4±7.3	79.5±7.1	79.3±7.4	−0.341	0.733
Females, n (%)	724 (71.3)	348 (72.0)	376 (70.5)	0.280	0.596
Distribution of age group, n (%)
65–74 years	292 (28.7)	138 (28.6)	154 (28.9)	0.277	0.871
75–84 years	454 (44.7)	213 (44.1)	241 (45.2)
≥ 85 years	270 (26.6)	132 (27.3)	138 (25.9)
Fracture types, n (%)
Femoral neck fractures	478 (47.0)	226 (46.8)	252 (47.3)	0.024	0.876
Intertrochanteric fractures	538 (53.0)	257 (53.2)	281 (52.7)
Surgical methods, n (%)
Artificial joint replacement	439 (43.2)	210 (43.5)	229 (43.0)	0.027	0.869
Closed reduction and internal fixation	577 (56.8)	273 (56.5)	304 (57.0)
Comorbidities, n (%)
Hypertension	409 (40.3)	191 (41.9)	218 (47.2)	0.688	0.407
Coronary heart disease	284 (28.0)	129 (26.7)	155 (29.1)	0.708	0.400
Cerebrovascular disease	429 (42.2)	214 (44.3)	215 (40.3)	1.636	0.201
Diabetes	217 (21.4)	100 (20.7)	117 (22.0)	0.235	0.628

Notes: Values are presented as the number (%). Plus–minus values of age is means±SD.

Table 2 Comparisons of Patient Perioperative Complications and Hospital Outcomes Between Two Groups

Complications	Total	Observation	Control	χ^2	P
Respiratory complications, n (%)
Overall incidence	344 (33.9)	142 (29.4)	202 (41.8)	8.173	0.004*
Pulmonary infection	307 (30.2)	125 (25.9)	182 (37.7)	0.211	0.004*
Respiratory failure	122 (12.0)	46 (9.5)	76 (14.3)	5.377	0.020*
Other complications, n (%)
Heart failure	378 (37.2)	178 (36.9)	200 (37.5)	3.237	0.846
Arhythmia	280 (27.6)	118 (24.4)	162 (30.4)	4.513	0.034*
Deep venous thrombosis of the lower limbs	485 (47.8)	242 (50.1)	243 (45.6)	2.068	0.150
Anemia	723 (71.2)	356 (73.7)	367 (68.9)	2.905	0.088
Low protein	605 (59.5)	284 (58.8)	321 (60.2)	0.214	0.644
Electrolyte disturbances	586 (57.7)	270 (55.9)	316 (59.3)	1.190	0.275
Hospital outcomes, n (%)
Length of hospital stay	13.0±5.0	13.2±4.9	12.8±5.2	−1.250	0.212
Total hospital costs	6.7±1.9	6.7±1.7	6.7±2.1	0.084	0.933

Notes: Plus–minus values are means±SD. In number of respiratory complications and other complications, values are presented as the number (%). *P < 0.05, statistical significance.

Figure 1 Seasonal distribution of respiratory complications between control and observation groups.

Table 3 Patient Demographics and Comorbidities Stratified by Fracture Types

	Femoral Neck Fractures			Intertrochanteric Fractures
	Observation	Control	P	Observation	Control	P
Age, mean ± SD (years)	78.0±7.1	78.3±7.3	0.703	80.7±6.9	80.2±7.3	0.419
Females, n (%)	160 (70.8)	173 (68.7)	0.610	188 (73.2)	203 (72.2)	0.813
Distribution of age group, n (%)
65–74 years	85 (37.6)	85 (33.7)	0.562	53 (20.6)	69 (24.6)	0.295
75–84 years	95 (42.0)	107 (42.5)		118 (45.9)	134 (47.7)
≥ 85 years	46 (20.4)	60 (23.8)		86 (33.5)	78 (27.7)
Surgical methods, n (%)
Artificial hip joint replacement	222 (88.1)	207 (91.6)	0.208	3 (1.2)	7 (2.5)	0.414
Closed reduction and internal fixation	30 (11.9)	19 (8.4)		254 (98.8)	274 (97.5)
Comorbidities, n (%)
Hypertension	97 (42.9)	110 (43.7)	0.872	108 (42.0)	130 (46.3)	0.323
Coronary heart disease	63 (27.9)	68 (27.0)	0.827	66 (25.7)	87 (31.0)	0.175
Cerebrovascular disease	92 (40.7)	94 (37.3)	0.446	122 (47.5)	121 (43.1)	0.305
Diabetes	39 (17.3)	49 (19.4)	0.538	61 (23.7)	68 (24.2)	0.900

Notes: Plus–minus values are means±SD. In number of females, distribution of age group, surgical methods, and comorbidities, values are presented as the number (%).

Table 4 Patient Perioperative Complications and Hospital Outcomes Stratified by Fracture Types

	Femoral Neck Fractures			Intertrochanteric Fractures
	Observation	Control	P	Observation	Control	P
Respiratory complications, n (%)
Overall incidence	65 (28.8)	95 (37.7)	0.039*	77 (30.0)	107 (38.1)	0.047*
Pulmonary infection	57 (25.2)	85 (33.7)	0.042*	68 (26.5)	97 (34.5)	0.043*
Respiratory failure	16 (7.1)	33 (13.1)	0.030*	30 (11.7)	43 (15.3)	0.219
Other complications, n (%)
Heart failure	67 (29.6)	97 (38.5)	0.042*	111 (43.0)	103 (36.7)	0.131
Arhythmia	55 (24.3)	83 (32.9)	0.038*	63 (24.5)	79 (28.1)	0.344
Deep venous thrombosis of the lower limbs	102 (45.1)	105 (41.7)	0.445	140 (54.4)	138 (49.1)	0.214
Anemia	151 (66.8)	158 (62.7)	0.347	205 (79.8)	209 (74.4)	0.138
Low protein	127 (56.2)	149 (59.1)	0.517	157 (61.1)	172 (61.2)	0.977
Electrolyte disturbances	135 (59.7)	150 (59.5)	0.963	135 (52.5)	166 (59.1)	0.127
Hospital outcomes, n (%)
Length of hospital stay	14.1±5.3	13.3±5.1	0.075	12.4±4.3	12.4±5.2	0.999
Total hospital costs	7.2±1.8	7.1±2.0	0.751	6.3±1.6	6.4±2.0	0.693

Notes: Plus–minus values are means±SD. In number of respiratory complications and other complications, values are presented as the number (%). *P < 0.05, statistical significance.