An association between cancer type and delirium incidence in Japanese elderly patients: A retrospective longitudinal study.

OBJECTIVE: There is not a known elevated prevalence of delirium in older adult cancer patients. However, it is unknown if the incidence of delirium varies by cancer type among older adult patients. Therefore, this study aimed to examine the association between the incidence of delirium and cancer type among older adult patients using a Japanese hospital-based administrative claims database. METHODS: A total of 76,868 patients over 65 years of age or older, first diagnosed with cancer on an initial date of hospitalization between April 2008 and December 2019, were included in this retrospective longitudinal study. Delirium was defined by the World Health Organization's International Statistical Classification of Diseases and Related Health Problems (ICD-10) codes or antipsychotic medication use. Cox proportional hazard models were performed to estimate the risk of delirium incidence according to 22 cancer types during the one-year hospitalization period. RESULTS: The incidence rates of delirium were 17.1% for men and 15.3% for women. Compared to gastric cancer, the risk of delirium was significantly higher for pancreatic cancer (HR: 1.26, 95% CI: 1.11-1.42 for men; HR: 1.27, 95% CI: 1.11-1.45 for women), leukemia (HR: 1.24, 95% CI: 1.09-1.41 for men; HR: 1.20, 95% CI: 1.03-1.41 for women), and oropharyngeal cancer (HR: 1.30, 95% CI: 1.10-1.54 for men; HR: 1.32; 95% CI: 1.02-1.72 for women) after adjusting for age, initial hospitalization year, antipsychotic medications, and surgery. CONCLUSIONS: As compared to gastric cancer, patients with pancreatic cancer, leukemia, oropharyngeal cancer were found to have a higher risk of developing delirium. Our study findings suggested that the risk of delirium incidence may vary by cancer type.

Prescribing Pattern of Hypnotic Medications in Patients Initiating Treatment at Japanese Hospitals: A Nationwide, Retrospective, Longitudinal, Observational Study Using a Claims Database.

BACKGROUND: Prolonged treatment of insomnia using benzodiazepine (BZD) receptor agonists, including BZD and non-BZD hypnotic drugs, can cause drug dependence, tolerance, abuse and other adverse events. These side effects are more common and/or severe in older adults taking different hypnotic drugs concomitantly. Therefore, a single prescription is limited to 30 daily doses for most BZD receptor agonists and restrictions apply to the prescription of more than three types of hypnotic drugs in Japan. Little is known, however, about the real-world prescribing pattern of hypnotic drugs in Japan. OBJECTIVE: We analysed prescribing patterns for hypnotic drugs in Japan to evaluate whether real-world use differs from guideline recommendations. METHODS: In this nationwide, retrospective, longitudinal, observational study, we analysed the types of hypnotic drugs prescribed, duration of medication and treatment setting in a subset of hospitals in Japan using a hospital-based administrative claims database (Medical Data Vision). Patients initiating treatment with hypnotic drugs between January 2012 and December 2016 were included in the analyses to assess the duration of medication and occurrence of co-prescription of a second and third hypnotic drug, within a year from prescription of the first hypnotic drugs. RESULTS: In 261,167 patients analysed, the first hypnotic drugs prescribed were BZDs (59.7%), non-BZDs (36.8%), a melatonin receptor agonist [MRA] (3.1%) and an orexin receptor antagonist [ORA] (0.4%). Benzodiazepine and non-BZD hypnotic drugs were mostly prescribed in inpatient settings (57.7% and 63.0%, respectively) and the MRA and ORA mostly in outpatient settings (62.6% and 65.4%, respectively). The departments that prescribed the most patients their first hypnotic drugs were internal medicine (23.6%), general surgery (11.8%), orthopaedic surgery (11.4%) and urology (5.3%). Of the total prescriptions of MRA and ORA as the first hypnotic drugs, 22.0% and 31.8% were in internal medicine, 4.4% each in general surgery, 6.0% and 4.5% in orthopaedic surgery, 9.7% and 4.4% in neurology, and 10.1% and 12.2% in psychiatry departments, respectively. Mean duration of medication was 1.13 months for non-BZDs, 1.15 months for BZDs, 1.29 months for the ORA and 1.83 months for the MRA. Overall, 5.3% (95% confidence interval 5.2-5.4) of patients were prescribed a second hypnotic drug; of these, 8.4% (95% confidence interval 8.0-8.9) were prescribed at least three hypnotic drugs within a year. Patients who were prescribed three or more hypnotic drugs received higher doses of the first drug than patients who received fewer hypnotic drugs. CONCLUSIONS: Benzodiazepine receptor agonists were the most common hypnotic drugs prescribed as the first drug to patients in Japan. Further education and awareness may be needed on the risk of complications and adverse events associated with these therapies. The duration of BZD receptor agonist use was shorter than for the MRA and ORA, in accordance with prescribing guidelines. Long-term use and co-prescribing of hypnotic drugs were also uncommon.

Training effect and fatigue in polypyrrole-based artificial muscles.

Artificial muscles based on an electrochemomechanical strain (ECMS) in conducting polymers, namely polypyrrole (PPy) film, have been studied from viewpoints of training, fatigue and aging by repeat cycles under tensile loads. ECMS was approximately 2% in a saline solution, resulting from both insertion and exclusion of Na(+) with solvated water molecules as well in the film. Transient responses of ECMS and current induced by voltage stimuli were measured under tensile stresses up to 5 MPa to see the training effect, fatigue and aging of the film. At higher stresses the film showed larger creeping, which resulted from realignment or conformation change, slipping and breaking of polymer chains. After the experience of large stresses, the training effect in ECMS was appreciably observed as an increase of the strain. Without stress the conductivity of the film was stable (no fatigue) upon an electrochemical cycle; however, under high tensile stresses the conductivity decreased remarkably (fatigue and aging). It is to be noted that straightened polymer chains can be easily oxidized and degraded due to lower pi-electron energy. The conversion efficiency from electrical to mechanical energy in this system was found to be less than 0.03%.

Work behaviors of artificial muscle based on cation driven polypyrrole.

A soft actuator mimicking natural muscles (artificial muscle) has been developed using a flexible conducting polymer of polypyrrole films, which were driven by electrical stimulus in a saline solution. The work characteristics were studied under various load stresses and found to behave like natural muscles. The artificial muscles shrunk and stiffened by the positive electrical stimulus by 2-3% at the maximum force of 5 MPa, and relaxed by application of negative voltages. At larger load stresses, the artificial muscle shrunk slowly as natural muscles do. The driving current also lasted longer at larger loads, indicating that the muscle sensed the magnitude of the load stress. During contraction of the muscle, the conversion efficiency from the electrical input and mechanical output energies was estimated to be around 0.06%. The maximum volumetric work was approximately estimated to be 100 kJ m(-3). These figures are unexpectedly small compared with those of natural muscles.

Tubular linear actuators using conducting polymer, polypyrrole.

Conducting polymers show an electrochemomechanical deformation (ECMD), which is able to be utilized as soft actuators. A tubular linear actuator of polypyrrole film is fabricated and the characteristics are examined. The film was electrochemically prepared on an acryl resin rod in an aqueous electrolyte solution of pyrrole and dodecylbenzensulfonic acid (DBS), followed by removing the rod. The actuations of tubular polypyrrole film due to ECMD in various conditions have been examined to clarify the mechanism. It has been found that the tubular actuator elongates upon reduction with the strain of 7%, which is more than twice of that observed in a rectangular film. The facts indicate that cations play the role of dopants instead of large DBS anion and the tubular structure gives the better performance for large strain.