Effectiveness of influenza vaccination on in-hospital death in older adults with respiratory diseases

Figures & data

Figure 1. Flow diagram.

Flowchart showing the selection of study participants and linkage to the Beijing Elderly Influenza Vaccination (EIV) database. Abbreviation: EIV, the Beijing Elderly Influenza Vaccination; UEBMI, Beijing Urban Employee Basic Medical Insurance.

Table 1. Patient characteristics by vaccination status.

	Total	Vaccinated	Not vaccinated
Periods of observation	399632	49733	349899
Age, mean (SD)	76.9 (9.0)	76.8 (7.7)	77.0 (9.1)
Female sex	44.8	40.6	45.4
Inpatient visits, mean (SD)	1.9 (3.5)	1.0 (1.6)	2.0 (3.6)
CCI, mean (SD)	2.5 (1.6)	2.2 (1.5)	2.5 (1.6)
Surgical operation	9.2	7.8	9.4
Alcohol-related diagnosis	0.02	0.01	0.03
Obesity-related diagnosis	52.2	51.8	52.2
COPD diagnosis	102057 (25.5)	15560 (31.3)	86497 (24.7)
Pnemonia/influenza diagnosis	110952 (27.8)	11954 (24.0)	98998 (28.3)
Asthma diagnosis	11866 (3.0)	1698 (3.4)	10168 (2.9)
Death	27784 (7.0)	1609 (3.2)	26175 (7.5)

Values are mean (SD) for continuous variables or proportions for categorical variables.

Abbreviation: CCI, Charleston Comorbidity Index.

All p-values <.001.

Table 2. Associations of influenza vaccination with in-hospital death among patients with respiratory disease by subtypes.

	Effect size (95% CI)
Disease subtypes	Influenza seasons	Summer months	Ratio of ORs
Respiratory disease
Basic model	0.35 (0.32, 0.38)	0.52 (0.48, 0.57)	0.67 (0.59, 0.76)
Adjusted model	0.41 (0.38, 0.45)	0.59 (0.54, 0.65)	0.70 (0.62, 0.80)
COPD
Basic model	0.35 (0.28, 0.43)	0.50 (0.38, 0.65)	0.70 (0.51, 0.98)
Adjusted model	0.39 (0.32, 0.49)	0.58 (0.44, 0.77)	0.67 (0.47, 0.98)
Pneumonia/influenza
Basic model	0.38 (0.34, 0.43)	0.56 (0.49, 0.64)	0.68 (0.57, 0.83)
Adjusted model	0.39 (0.32, 0.49)	0.62 (0.54, 0.71)	0.77 (0.64, 0.93)
Asthma
Basic model	0.20 (0.03, 1.52)	0.53 (0.06, 4.84)	0.38
Adjusted model	0.22 (0.03, 1.50)	0.74 (0.09, 6.24)	0.29

Abbreviation: OR, odds ratio.

a. The reference group was those not vaccinated in the current seasons. The basic model was adjusted for age, age square, and sex. The adjusted model was adjusted for age, age squared, sex, number of inpatient visits in the past 12 months, Charleston Comorbidity Index, operation status, hospital size, quintiles of propensity score, obesity-related diagnosis, and alcohol-related diagnosis.

b. For asthma, CIs of the ratio of ORs were not reported because of the small number of events included.

Figure 2. Associations of influenza vaccination with in-hospital death among patients with respiratory disease by subgroups.

Boxes represent odds ratios (ORs) of in-hospital death among older patients with respiratory disease during influenza seasons and summer seasons. The model was adjusted for age, age squared, sex, number of inpatient visits in the past 12 months, Charleston Comorbidity Index, operation status, hospital size, quintiles of propensity score, obesity-related diagnosis, and alcohol-related diagnosis. Ratio of ORs were estimates adjusted for measured and unmeasured confounders. Details of subgroup analyses are shown in the supplementary methods.