Objective To compare the clinical effects of vancomycin, linezolid alone, and their separate combination with spleen polypeptide in the treatment of severe community-acquired pneumonia (CAP) in children with a history of recurrent respiratory infections.

Methods A total of 296 children with severe CAP and a history of recurrent respiratory infections were selected as study subjects and randomly divided into four groups: vancomycin group (vancomycin alone), linezolid group (linezolid alone), combined group A (vancomycin combined with spleen polypeptide), and combined group B (linezolid combined with spleen polypeptide), with 74 patients in each group. The curative effects, recovery process (time to normalization of body temperature, time to improvement of cough, time to improvement of respiration, length of hospital stay), adverse reactions, and direct medical costs were compared among the four groups. Decision tree models and cost-effectiveness analysis were used to compare the economics of each treatment plan.

Results The total effective rates in the linezolid group, combined group A, and combined group B were 83.78%, 86.49%, and 97.30%, respectively, which were all higher than 71.62% in the vancomycin group, and the combined group B had a higher effective rate than the linezolid group and combined group A (P < 0.05). The time to normalization of body temperature, improvement of respiration, improvement of cough, and length of hospital stay were shorter in the linezolid group, combined group A, and combined group B than in the vancomycin group, and were shorter in the combined group B compared to the linezolid group and combined group A (P < 0.05). There was no statistically significant difference in the occurrence of adverse reactions among the four groups (P>0.05). There were no statistically significant differences in treatment costs, examination/testing costs, and hospitalization costs among the four groups (P>0.05). The treatment costs and total costs were higher in the vancomycin group, combined group A, linezolid group, and combined group B in ascending order, with statistically significant between-group difference (P < 0.05). The cost-effectiveness ratios from high to low were combined group A (75.84), vancomycin group (73.22), linezolid group (32.87), and combined group B (32.69). Sensitivity analysis showed that the cost-effectiveness ratio analysis results were stable and reliable.

Conclusion Among the four treatment options, the combination of linezolid and spleen polypeptide has the best therapeutic effect in severe CAP children with a history of recurrent respiratory infections, with the most significant clinical benefit and cost-effectiveness advantages.