Fig. 5

Forest plots of the respiratory illness mortality risk according to the frailty status. A The pooled HR and 95% CI of the respiratory illness mortality in the frail group compared with the robust group; B The pooled HR and 95% CI of the respiratory illness mortality in the prefrail group compared with the robust group; C The pooled HR of the respiratory illness mortality risk per 0.1 increase in the frailty index score. CI = confidence interval, HR = hazard ratio