In this study, there were four independent factors affecting the occurrence of double-J stent encrustation after upper urinary tract calculi surgery. The four independent factors are BMI > 23.9, preoperative urine routine white blood cell quantification, double-J tube insertion time, postoperative water consumption did not reach 2000 ml/d.

This study found that BMI > 23.9 is a risk factor for double-J stent encrustation (OR = 1.648). Urinary calculus is not an isolated disease but the result of the joint action of metabolic syndrome, obesity, diabetes, and cardiovascular disease. However, obesity is a factor that can be controlled artificially [14]. Common complications of obesity are hypertension and diabetes, which have a bidirectional relationship with stones [15]. A cross-sectional study of 605 participants followed up for an average of 47 months indicated a direct relationship between stone disease and BMI, which can be used as a predictor of stone disease development in clinical practice [16]. Therefore, in clinical work, medical staff should pay attention to patients’ weight management. During discharge education, we should formulate individualized weight loss programs for obese patients, eat a sensible diet, strengthen exercise, and regularly monitor measurements; we should also strengthen discharge follow-up, regularly inquire about the implementation of the weight loss program, improve the patient’s awareness and attention, and effectively control the weight.

It was found that abnormal quantitative urine white blood cells before the operation was a risk factor for double-J stent encrustation (OR = 1.149). Studies have pointed out [5] that the proportion of double-J stent encrustation formation in patients with urinary tract infections (92.9%) is higher than that in non-infected patients (73.2%). This reminds us to be vigilant in clinical work for those with abnormal quantitative urine white blood cells before operation. If there is any abnormality, the medical staff should conduct bacterial culture, identification, and drug sensitivity test in time and use antibiotics reasonably according to the test results for treatment; medical staff rationally use antimicrobial drugs when discharged from the hospital. At the same time, they should instruct patients to strengthen their nutrition, exercise regularly, improve immunity, and implement whole-process health management to improve patient maintenance compliance and reduce the incidence of urinary tract infections.

This study found that the time of double-J tube intubation was a risk factor for double-J stent encrustation (OR = 0.566). Studies have shown that the only risk factor for double-J tube stones is the indwelling time [17]. In one study, a total of 47.0% of stents encrusted, with encrustation rates ranging from 26.8% for less than 6 weeks, 56.9% for 6 to 12 weeks, and 75.9% for more than 12 weeks [18]. Studies by Legrand F et al. have shown that the time of double-J tube intubation is positively correlated with the incidence of double-J stent encrustation [19]. Therefore, medical staff should follow-up in time to remind patients to take the tube on time. Due to the condition requiring a longer indwelling time, the medical staff reminds the patient to recheck regularly and shorten the double-J tube insertion time after understanding the patient’s urinary stones composition and body metabolic environment.

This study found that water intake not reaching 2000 ml/d was an independent risk factor for surface stones (OR = 8.514). Tasian et al. [20] study pointed out that less than 50% of patients ensured adequate daily fluid intake. In a large meta-study [21], compared with those who consumed less than 1000 mL/d, the risk of urinary stones was reduced by about half in those who consumed more than 2000 mL/d(RR = 0.56, 95% CI 0.48–0.65, P < 0.001), but there is still some controversy about the intake of liquid types, such as tap water, mineral water, fruit juice, tea, and coffee. Therefore, medical staff should emphasize that the amount of drinking water should be more than 2000 ml/d, and recommend that patients carry drinking water bottles with scales or capacity marks every day to improve patient compliance; at the same time, medical staff should strengthen follow-up visits, adopt live webcasts, and establish WeChat groups Communication and other means to make patients aware of the importance of drinking more water for the prevention of double-J stent encrustation.