Data on risk factors for non-adherence to doctors' and pharmacists' instructions to discontinue medications prior to surgery are lacking. This study aimed to identify characteristics and risk factors for such non-adherent patients. Patients and Methods: Data (including patient age, sex, prescription medications, comorbidities, presence of roommate at home, and number of days between receiving instruction and surgery) of 887 patients who used medications affecting surgery at a university hospital from April 2017 to March 2020 were retrospectively evaluated. The primary endpoint was to investigate the rate of non-adherence and to explore independent risk factors for non-adherence (with age categorized as ≥65 [versus <65] years). Secondary endpoints included analysis of limited number of departments subgroup and a sensitivity analysis (with age categorized as ≥75 [versus <75] years) to confirm the robustness of the primary endpoint results. Independent risk factors for non-adherence were identified using logistic regression analysis. Results:The non-adherence rate was 11.4% (n=101/887), median age (interquartile range) at admission was 73 (70-79) years, and proportion of male patients was 81.2% (n=82). The main analysis adjusted for age ≥65 (versus <65) years showed age as a risk factor for increased nonadherence (adjusted odds ratio: 2.1, 95% confidence interval: 1.09-4.05; p=0.027). However, analyses adjusted for departments (other than urology, gynecology, and breast surgery, with a large sex bias in hospitalized patients) and for age ≥75 (versus <75) years showed no such risk. Conclusion: Age ≥65 years was associated with a higher risk of non-adherence to medications that should be discontinued before surgery. It is important for doctors and pharmacists to ensure that patients at high risk for non-adherence are aware of the importance of adherence. Our findings may help identify patients at high risk for non-adherence to such medications.

BackgroundFew studies have reported the dosage of cefmetazole (CMZ) for intraoperative antimicrobial prophylaxis in patients underwent surgery for colorectal cancer. We therefore examined the optimal intraoperative dosage of CMZ according to pharmacokinetic/pharmacodynamic (PK/PD) theory in patients who undergoing surgery for colorectal cancer.MethodsThe study group comprised 23 patients with colorectal cancer who underwent surgery, using CMZ as antimicrobial treatment to prevent postoperative infection. CMZ was administered intravenously within 60 min before surgery. PK/PD analysis was performed by population pharmacokinetic analysis and Monte-Carlo simulation.ResultsThe final population pharmacokinetic parameters of CMZ were as follows: CLCMZ = 0.0704 × creatinine clearance (Ccr) and VdCMZ = 0.163 × body weight (Bw). In patients with a Ccr of ≥90 to <130 mL/min, the probability of achieving concentrations exceeding MIC was 52.9 to 82.2% at 2 h after the initial dose and less than 20% at 3 h after the initial dose.ConclusionsAdditional doses of CMZ should be given every 2 h in patients with a Ccr of ≥90 to <130 mL/min, every 3 h in those with a Ccr of ≥50 to <90 mL/min, and every 4 to 5 h in those with a Ccr of ≥10 to <50 mL/min.

We previously developed a computerized clinical decision support system based on national consensus guidelines and previous studies. This system was used to assess the risk of venous thromboembolism. In this study, we examined the risk factors for venous thromboembolism in patients who underwent lower limb orthopedic surgery using our risk scoring system, to investigate the association between the total risk score and the occurrence of venous thromboembolism. We retrospectively evaluated the records of 649 patients who underwent lower limb orthopedic surgery at a tertiary care center in Japan between January 2015 and August 2018. Venous thromboembolism was confirmed using ultrasonography or computed tomography angiography. The computerized clinical decision support system was used throughout the hospitalization period. Independent risk factors for postoperative venous thromboembolism were identified using logistic regression analysis. Age (≥68 years) was significantly associated with an increased risk of venous thromboembolism (adjusted odds ratio: 1.06, 95% confidence interval: 1.03–1.09; P < 0.001). Furthermore, the Cochran–Armitage trend test revealed a significant positive correlation between the total risk score and the occurrence of venous thromboembolism ( P < 0.001). Our risk scoring system may be used preoperatively to determine the need for venous thromboembolism prophylaxis. This study suggests that age (≥68 years) may be a risk factor for venous thromboembolism after lower limb orthopedic surgery. Additional studies are needed to validate these results.

We developed a computerized clinical decision support system (CCDSS) for venous thromboembolism (VTE) risk assessment. We aimed to demonstrate its relevance and evaluate associations between risk level and VTE incidence in patients undergoing total hip/knee arthroplasty. In this case-control study, VTE was confirmed using ultrasonography/computed tomography angiography in 1098 adults at a tertiary care hospital over five years (2013-2018). Postoperative VTE incidence was classified into three risk levels (moderate, high, and highest). The overall VTE incidence was 11.7%, which increased with a risk level of 0%, 5.8%, and 12.8% in moderate-risk, high-risk, and highest-risk patients, respectively. Highest-risk patients were significantly more likely to develop VTE than high-risk patients (odds ratio [OR] 2.4; 95% confidence interval [CI] 1.2-5.5; p = 0.01). VTE development was more likely in patients with risk scores ≥4 relative to those with risk scores of 2–3 (OR 1.8; 95% CI 1.2-2.7; p = 0.003) and −1 to 1 (OR 3.3; 95% CI 1.6-7.7; p < 0.001). This study indicates that risk level and VTE incidence are associated; our scoring system appears useful for patients undergoing total hip/knee arthroplasty.