To investigate the risk factors for progression to sepsis in patients with mild to moderate infectious diseases.

The clinical data of 390 patients with clinically diagnosed infectious diseases from September 2019 to December 2021 were retrospectively analyzed. According to whether or not sequential organ failure assessment (SOFA) score ≥ 2 on admission, 390 patients were divided into a sepsis group (165 cases) and a mild-moderate infection group (225 cases). The general data, laboratory test indexes, and immunological indexes were compared between the two groups. The Lasso regression model and multivariate Logistic regression model were used to screen the independent factors for influencing the progression of mild-moderate infection to sepsis. The receiver operating characteristic (ROC) curve was used to assess the predictive effectiveness of each correlation factor.

In the sepsis group, the patients were older, the time interval between disease onset and hospital arrival was shorter, the heart rate and respiration were faster, the incidences of cardiovascular and cerebrovascular diseases, diabetes, and hypertension were higher, and the levels of admission temperature, leukocytes, neutrophils, red blood cell distribution width (RDW), neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio, procalcitonin, C-reactive protein, aspartate aminotransferase, total bilirubin, serum creatinine, blood urea, lactate dehydrogenase, hydroxybutyrate dehydrogenase, creatine kinase, creatine kinase MB, ferritin, lactic acid, prothrombin time, activated partial thromboplastin time, D-dimer, interleukin-6 (IL-6), IL-10, IL-6/IL-4, and IL-6/IL-10 were all much higher than those in the mild-moderate infection group; whereas, the levels of lymphocytes, monocytes, hemoglobin, platelets, hematocrit, cholinesterase, albumin, blood oxygen saturation, IL-4, tumor necrosis factor-alpha (TNF-α), interferon γ, and TNF-α/IL-10 were much lower (all P<0.05). The Lasso regression model and multivariate Logistic regression analysis revealed that the RDW [odds ratio (OR) = 1.399, 95% confidence intervals (CI) (1.122, 1.743), P = 0.003], NLR [OR = 1.050, 95%CI (1.010, 1.091), P = 0.013], total bilirubin [OR = 1.111, 95%CI (1.055, 1.170), P<0.001], blood urea [OR = 1.172, 95%CI (1.041, 1.320), P = 0.009], and IL-6 [OR = 1.006, 95%CI (1.002, 1.010), P = 0.002] were independent risk factors for mild-moderate infection progressing to sepsis, while the platelet [OR = 0.994, 95%CI (0.990, 0.997), P = 0.001] and albumin [OR = 0.866, 95%CI (0.799, 0.939), P<0.001] were independent protective factors. The ROC curve showed that the area under the curve (AUC) of platelets was 0.756 [95%CI (0.705, 0.808), P < 0.001], AUC of RDW was 0.748 [95%CI (0.699, 0.798), P < 0.001], AUC of NLR was 0.786 [95%CI (0.738, 0.834), P < 0.001], AUC of total bilirubin was 0.738 [95%CI (0.685, 0.790), P < 0.001], AUC of albumin was 0.795 [95%CI (0.749, 0.840), P < 0.001], AUC of blood urea was 0.780 [95%CI (0.729, 0.830), P < 0.001], AUC of IL-6 was 0.801 [95%CI (0.756, 0.845), P < 0.001], and AUC of combinated indicator was 0.939 [95%CI (0.915, 0.963), P < 0.001]. The predictive effectiveness of combined indicator model was significantly higher than that of IL-6 (Z = 6.519, P < 0.001), NLR (Z = 6.258, P < 0.001), blood urea (Z = 6.632, P < 0.001), platelet (Z = 7.412, P < 0.001), RDW (Z = 7.631, P < 0.001), albumin (Z = 6.164, P < 0.001), and total bilirubin (Z = 8.348, P < 0.001).

The RDW, NLR, total bilirubin, blood urea, and IL-6 are independent risk factors for mild-moderate infection progressing to sepsis, while the platelet and albumin are independent protective factors. The combined indicator has better predictive efficacy than each independent correlation factor.