Impact of serum C-reactive protein measurements in the first 2 days on the 30-day mortality in hospitalized patients with severe community-acquired pneumonia: A cohort study

Introduction: The purpose of the study is to evaluate the impact of daily consecutive measurements of C-reactive protein (CRP) in the initial 2 days of hospitalization on the 30-day all-cause mortality in patients with severe community-acquired pneumonia (CAP). Methods: We used 4 different thresholds of fractional decrease (FD) in CRP at the second day of admission (CRP2) of 25%, 30%, 40%, and 60%. In addition, we studied the association of each of these thresholds with the 30-day all-cause mortality. Results: The mean age was 64 ± 20; males, 59%. The 30-day mortality rate was 18% (20/111). The mean serum CRP levels at the first day of all study group and CRP2 were 203 ± 98 vs 146 ± 92 mg/L, respectively, P = .05. The mean FD in CRP2 levels among the survivors was 33 %, whereas among the nonsurvivors, was 7%, P < .001. Multiple regression analysis revealed that FD less than 25% in CRP2 was associated with 30-day all-cause mortality, odds ratio of 3.07 (95% confidence interval, 2.84-5.03), P = .002, compared with those with FD more than 25% in CRP2. Conclusions: Fractional decrease less than 25% in CRP levels at the second day was significantly associated with 30-day all-cause mortality in hospitalized patients with severe CAP.