Abstract: Objective  To explore the influencing factors of constipation in maintenance hemodialysis (MHD) patients and to construct a column chart prediction model.  Methods  A total of 135 patients who underwent MHD in Huai’an Second People's Hospital from April 2021 to June 2023 were regarded as the modeling group. A total of 58 MHD patients from July 2023 to November 2024 were recruited as the validation group. According to the occurrence of constipation during MHD, the modeling group was assigned into constipation group (n=56) and non-constipation group (n=79). The influencing factors of constipation in the MHD patients were analyzed using multivariate logistic regression. A column chart prediction model for constipation risk in MHD patients was then constructed using the R software. Predictive performance of the model was evaluated through receiver operating characteristic (ROC) curve, Hosmer-Lemeshow test, and calibration curve.  Results Among the 193 MHD patients, a total of 78 cases experienced constipation, with an incidence rate of 40.41%. Compared with the non-constipation group, the constipation group had higher rates of diabetes nephropathy, dialysis age≥5 years, and lying in bed in most daytime (c2=5.539, 5.053 and 4.293; P=0.019, 0.025 and 0.038), while plasma albumin was lower (t=4.161, P＜0.001). Multivariate logistic regression found that diabetes nephropathy (OR=5.739, 95% CI: 2.089～15.767, P=0.001), dialysis age ≥5 years (OR=6.287, 95% CI: 2.246～17.598, P＜0.001), and lying in bed in most daytime (OR=8.396, 95% CI: 2.348～30.022, P=0.001) were the independent risk factors for constipation in MHD patients (P＜0.05), and plasma albumin was a protective factor for constipation in MHD patients (OR=0.865, 95% CI: 0.788～0.950, P=0.002). The column chart showed that the higher the total score of MHD patients, the higher the risk of constipation. ROC curve showed that the area under the curve (AUC) of the modeling group and the validation group were 0.806 (95% CI: 0.733～0.879) and 0.879 (95% CI: 0.796～0.963) respectively, indicating higher predictive discrimination of the column chart. Hosmer-Lemeshow test and calibration curve indicated that the model had higher prediction consistency.  Conclusion   The risk of constipation in MHD patients is related to primary disease, dialysis age, daily living conditions and plasma albumin level. The nomogram model established based on the four risk factors has good efficacy in predicting the risk of constipation in MHD patients and is helpful for clinical prediction and prevention of constipation.

Key words: Maintenance hemodialysis, Constipation, Influencing factor, Column chart