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Volume 32, Number 6—June 2026

Research

Association of Frailty and Frailty Trajectory with Risk for Respiratory Infectious Diseases

Jin Yang1, Hao Yan1, Huan Chen, Dan Liu, Zhihao Li, and Chen MaoComments to Author 
Author affiliation: School of Public Health, Southern Medical University, Guangzhou, China; National Institute of Health Data Science of China, Southern Medical University, Guangzhou

Main Article

Table 2

Hazard ratios of incident RIDs in first assessment of association of frailty and frailty trajectory with risk for RIDs*

Category Events/no. participants Model 1
 Model 2
HR (95% CI) p value HR (95% CI) p value
Grouped by physical frailty
Nonfrail 230,81/269,882 Referent Referent
Prefrail 18,834/144,734 1.51 (1.48–1.54) <0.001 1.32 (1.30–1.35) <0.001
Frail 2,193/9,075 2.93 (2.81–3.06) <0.001 2.01 (1.92–2.10) <0.001
Per 1-point increase
1.41 (1.39–1.42)
 <0.001
1.26 (1.24–1.27)
 <0.001
Grouped by frailty index
Nonfrail 19,181/253,296 Referent Referent
Prefrail 19,014/144,591 1.68 (1.65–1.71) <0.001 1.50 (1.47–1.53) <0.001
Frail 5,913/25,804 3.02 (2.93–3.11) <0.001 2.29 (2.22–2.37) <0.001
Per 0.1-point increase
1.64 (1.62–1.66)
 <0.001
1.47 (1.45–1.49)
 <0.001
RID subgroups
Influenza
Grouped by physical frailty
Nonfrail 1,209/269,882 Referent Referent
Prefrail 931/144,734 1.42 (1.30–1.55) <0.001 1.30 (1.19–1.42) <0.001
Frail 132/9,075 3.18 (2.65–3.80) <0.001 2.44 (2.02–2.95) <0.001
Per 1-point increase 1.39 (1.33–1.46) <0.001 1.29 (1.23–1.36) <0.001
Grouped by frailty index
Nonfrail 1,054/253,296 Referent Referent
Prefrail 924/144,591 1.51 (1.38–1.65) <0.001 1.41 (1.29–1.54) <0.001
Frail 291/25,804 2.64 (2.31–3.00) <0.001 2.19 (1.90–2.51) <0.001
Per 0.1-point increase 1.52 (1.44–1.59) <0.001 1.41 (1.34–1.49) <0.001
OALRTI
Grouped by physical frailty
Nonfrail 13,070/269,882 Referent Referent
Prefrail 10,308/144,734 1.44 (1.40–1.48) <0.001 1.27 (1.24–1.30) <0.001
Frail 1,131/9,075 2.52 (2.37–2.68) <0.001 1.78 (1.67–1.90) <0.001
Per 1-point increase 1.34 (1.33–1.36) <0.001 1.21 (1.19–1.23) <0.001
Grouped by frailty index
Nonfrail 10,595/253,296 Referent Referent
Prefrail 10,677/144,591 1.70 (1.66–1.75) <0.001 1.54 (1.49–1.58) <0.001
Frail 3,237/25,804 2.89 (2.78–3.01) <0.001 2.26 (2.17–2.36) <0.001
Per 0.1-point increase 1.62 (1.59–1.64) <0.001 1.47 (1.44–1.49) <0.001
Pneumonia
Grouped by physical frailty
Nonfrail 11,221/269,882 Referent Referent
Prefrail 10,204/144,734 1.66 (1.62–1.71) <0.001 1.43 (1.39–1.47) <0.001
Frail 1,370/9,075 3.70 (3.50–3.92) <0.001 2.39 (2.25–2.53) <0.001
Per 1-point increase 1.52 (1.50–1.54) <0.001 1.34 (1.32–1.36) <0.001
Grouped by frailty index
Nonfrail 9,413/253,296 Referent Referent
Prefrail 9,940/144,591 1.73 (1.68–1.78) <0.001 1.52 (1.47–1.56) <0.001
Frail 3,442/25,804 3.39 (3.26–3.53) <0.001 2.45 (2.35–2.56) <0.001
Per 0.1-point increase 1.73 (1.70–1.76) <0.001 1.51 (1.49–1.54) <0.001

*Data from UK Biobank (https://www.ukbiobank.ac.uk) collected during 2006–2010. Model 1 is adjusted for age and sex; model 2 is adjusted for all covariates. HRs and 95% CIs were estimated using Cox proportional hazards models. A 2-sided p<0.05 was considered statistically significant. FI, frailty index; HR, hazard ratio; OALRTI, other acute lower respiratory tract infection; PF, physical frailty; RID, respiratory infectious disease.

Main Article

1These first authors contributed equally to this article.

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