Risk Factors Analysis for Hemoglobin Decline Caused by Diagnostic Blood Collection in Respiratory Department in North China: A Case-Control Study

PURPOSE: This study aimed to investigate the correlation between hemoglobin decline and diagnostic blood collection in the respiratory department and analyze the decline's risk factors. PATIENTS AND METHODS: A case-control study in the respiratory department of a national tertiary hospital in north China, multivariable logistic regression analysis was used to find the risk factors. Patients excluding other factors affecting hemoglobin other than blood collection in the year 2021 were enrolled and divided into two groups according to the D-value of hemoglobin. The degree of hemoglobin decline caused by diagnostic blood collection between discharge and admission and its risk factors were analyzed. RESULTS: Among the 530 patients screened in the study, ΔHb (the D-value of hemoglobin between discharge and admission) showed a skewed distribution with an average value of −4.38±0.514 g/L. We defined the D-value less than mean-2SD (ΔHb<-5.408) as a significant hemoglobin decline, by which the patients were categorized into two groups. Some variables had apparent differences between the two groups. By multivariable logistic regression analysis on these variables, the independent risk factors for significant hemoglobin decline (ΔHb<-5.408g/L) were revealed: age (OR=1.020, 95% CI 1.008–1.032, p=0.001), Male gender (OR=1.544, 95% CI 1.011–2.358, p=0.044), hemoglobin value at admission (OR=1.052, 95% CI 1.039–1.065, p<0.001), total blood collection volume (OR=1.021, 95% CI 1.010–1.032, p<0.001). CONCLUSION: In the respiratory department, older male and more diagnostic blood collection mean higher risks of significant hemoglobin decline. Surprisingly, the lower the hemoglobin value at admission, the lower the risk.