Estimating the prevalence of chronic kidney disease in the older population using health screening data in Japan.

BACKGROUND: In aging societies, the prevalence of chronic kidney disease (CKD) is expected to increase but may be underestimated because many asymptomatic patients remain undiagnosed. This study aimed to estimate the CKD prevalence among the general older population in Japan. METHODS: This cross-sectional study used health screening data from the Japan Health Insurance Association collected between April 2014 and March 2023. Data from older people aged 65-90 years who underwent renal function screening for estimated glomerular filtration rate (eGFR) and urine protein tests were analyzed. CKD was defined as eGFR < 60 mL/min/1.73 m2 or proteinuria ≥ 1 + . Inverse probability weighting was used to account for the selection bias. The variables used for weighting were age, sex, insurance status, and the number of previous screenings. RESULTS: Among 2.98 million older individuals, 588,809 (19.7%) had undergone screening (median [IQR] age, 69.9 [67.9-76.2] years, 337,862 women [57.4%]). Regarding the weighted CKD prevalence, 25.3% of the individuals aged 65-90 years had CKD; 11.8% of those aged 65-75 years and 34.6% of those aged 75 years and over showed an increase in prevalence with age. Among the patients with CKD, over half exhibited mild renal dysfunction without proteinuria. Hypertension and diabetes were common comorbidities in older patients with CKD. CONCLUSIONS: This cross-sectional study revealed that the weighted prevalence of CKD in the older population aged 65-90 years was high (one in four individuals), indicating that it increases with age. Further studies are required to examine the clinical significance of these findings.

Risk factors associated with hospitalization in patients with asymptomatic or mild COVID-19 in public accommodation facilities in Tokyo.

INTRODUCTION: In Japan, patients with coronavirus disease 2019 (COVID-19) who do not require medical intervention are provided care in recovery accommodation facilities (RAFs). However, some patients may require hospitalization if their symptoms become more severe during their stay. We conducted an observational study using epidemiological data of patients with COVID-19 admitted to RAFs in Tokyo. METHODS: This was an observational cohort study using data from COVID-19 patients admitted to one of the RAFs in Tokyo from December 2020 to November 2021. Admissions to the facilities were limited to patients with asymptomatic or mild COVID-19 with no underlying disease or at least stable underlying disease at the time of admission. Patients were hospitalized when they required oxygen administration or when they had, or persistent fever, or severe respiratory symptoms. We evaluated the association between hospitalization and the risk factors for hospitalization using a Cox regression model. RESULTS: The number of patients with COVID-19 admitted to the RAF was 6176. The number of hospitalized patients was 393 (6.4%), and the median length of stay was 5.50 days (IQR: 4.50, 6.50). In the Cox regression analysis, the hazard ratio increased with age and was significantly higher among patients aged >60 years (HR = 10.23, 95% CI: 6.72-15.57) than those in other age groups. This trend is similar to that observed in the sensitivity analysis. CONCLUSION: Patients with diabetes, the elderly, obesity, and medications for gout and psychiatric diseases may be at a high risk of hospitalization. In particular, an age over 60 years was strongly associated with hospitalization.

Changes in Drug Utilization After Publication of Clinical Trials and Drug-Related Scandals in Japan: An Interrupted Time Series Analysis, 2005-2017.

BACKGROUND: Breaches of ethics undermine the practice of medicine. In Japan, two major scandals involving clinical research and drug marketing occurred after the publication of clinical trials. To study the effects of those scandals, we evaluated changes in the use of first-generation angiotensin II receptor blockers (ARBs) after publication of relevant clinical trials and also after the subsequent scandals. METHODS: We conducted a quasi-experimental design of an interrupted time series analysis (ITSA) on nationwide monthly drug-market data covering 12 years (2005 to 2017) in Japan. The main outcome was the use of first-generation ARBs (valsartan, candesartan, and losartan). The two exposures were the publication of ARB-related clinical-trial results (October 2006) and subsequent ARB-related scandals involving research and marketing (February 2013). A generalized estimating equation model was fitted for ITSA with a log link, Poisson distribution, robust variance estimators, and seasonality adjustment. RESULTS: The publication of clinical trials was associated with 12% increase in the use of first-generation ARBs in Japan, and the subsequent ARB-related scandals was associated with 19% decrease. The decrease in the use of first-generation ARBs after the scandals was greater than the increase in their use after the publication of clinical-trial results. The net effect of the two exposures was a 9% decrease in the use of first-generation ARBs. CONCLUSIONS: The scandals were associated with decrease in the use of first-generation ARBs, and that decrease was greater than the increase associated with the publication of "successful" clinical trials, making the net effect not zero but negative.

Laxative use and mortality in patients on haemodialysis: a prospective cohort study.

BACKGROUND: Patients on haemodialysis (HD) are often constipated. This study aimed to assess the relationship between constipation and mortality in such patients. In this study, constipation was defined as receiving prescription laxatives, based on the investigation results of "a need to take laxatives is the most common conception of constipation" reported by the World Gastroenterology Organization Global Guidelines. METHODS: This cohort study included 12,217 adult patients on HD enrolled in the Japan-Dialysis Outcomes and Practice Patterns study phases 1 to 5 (1998 to 2015). The participants were grouped into two based on whether they were prescribed laxatives during enrolment at baseline. The primary endpoint was all-cause mortality in 3 years, and the secondary endpoint was cause-specific death. Missing values were imputed using multiple imputation methods. All estimations were calculated using a Cox proportional hazards model with an inverse probability of treatment weighting using the propensity score. RESULTS: Laxatives were prescribed in 30.5% of the patients, and there were 1240 all-cause deaths. There was a significant association between laxative prescription and all-cause mortality [adjusted hazard ratio (AHR), 1.12; 95% confidence interval (CI): 1.03 to 1.21]. Because the Kaplan-Meier curves of the two groups crossed over, we examined 8345 patients observed for more than 1.5 years. Laxative prescription was significantly associated with all-cause mortality (AHR, 1.35; 95% CI: 1.17 to 1.55). The AHR of infectious death was 1.62 (95% CI: 1.14 to 2.29), and that of cancerous death was 1.60 (95% CI: 1.08 to 2.36). However, cardiovascular death did not show a significant inter-group difference. CONCLUSIONS: Constipation requiring use of laxatives was associated with an increased risk of death in patients on HD. It is important to prevent patients receiving HD from developing constipation and to reduce the number of patients requiring laxatives.

Quality of Care in Chronic Kidney Disease and Incidence of End-stage Renal Disease in Older Patients: A Cohort Study.

BACKGROUND: The quality of care received by a growing number of older patients with chronic kidney disease (CKD) has not been adequately examined. OBJECTIVE: The objective of this study was to assess the quality of CKD care among older patients and to clarify its association with the incidence of end-stage renal disease (ESRD). RESEARCH DESIGN: This was a population-based cohort study. SUBJECTS: Older (65 y and above) CKD patients diagnosed between October 2010 and September 2014 from the National Database of Health Insurance Claims of Japan. MEASURES: A composite quality score (QS) of 3 quality measures for CKD care during the 6 months after CKD diagnosis was computed. The validated quality measures included urine testing for proteinuria, nutritional guidance, and nonsteroidal anti-inflammatory drugs avoidance. To assess the association between the QS and ESRD incidence, we used instrumental variable analysis after stratification for the history of diabetes. RESULTS: Among the 890,773 older CKD patients, 2.9% progressed to ESRD (incidence rate of 12.5 per thousand person-years). In total, 59.9% underwent urine testing, 4.5% received nutritional guidance, and 91.2% avoided regular use of nonsteroidal anti-inflammatory drugs. An instrumental variable analysis revealed that a higher QS was associated with-lower ESRD incidence in patients diagnosed with diabetes (hazard ratio: 0.25, 95% confidence interval: 0.24-0.27 for each point higher score) but not in patients without a diagnosis of diabetes (hazard ratio: 0.99, 95% confidence interval: 0.92-1.05). CONCLUSION: Among older CKD patients, quality of CKD care varied between patients, and better quality of CKD care was associated with a lower ESRD incidence in patients with diabetes but not in nondiabetic patients.

Development and validation of a prediction model for failed shockwave lithotripsy of upper urinary tract calculi using computed tomography information: the S3HoCKwave score.

PURPOSE: To develop and validate a new clinical prediction model that accurately predicts the failure of shockwave lithotripsy (SWL) using information obtained from non-contrast-enhanced computed tomography (NCCT). METHODS: This multicentre retrospective cohort study consecutively enrolled patients diagnosed with upper urinary tract calculi by NCCT at five hospitals in Japan from January 1, 2006 to December 31, 2016. Among the candidate predictors, we selected the six most significant predictors a priori. The main outcome was SWL failure after three sessions. Model calibration was evaluated by the calibration slope and the Hosmer-Lemeshow test. Discrimination was evaluated by the receiver-operating characteristic curves and the area under the curve (AUC). A multivariable logistic regression analysis was performed; based on the estimated ß coefficients, predictive scores were generated. RESULTS: Of 2695 patients, 2271 were included. Patients were divided into the development cohort (1666 patients) and validation cohort (605 patients) according to geographical factors. We developed a clinical prediction model with scores ranging from 0 to 49 points. We named the prediction model the S3HoCKwave score based on the initials of the predictors (sex, skin-to-stone distance, size, Hounsfield units, colic, and kidney or ureter). As a result of internal validation, the optimism-corrected AUC was 0.72. In the validation cohort, the Hosmer-Lemeshow test did not show statistical significance (P = 0.33), and the AUC was 0.71 (95% confidence interval 0.65-0.76). CONCLUSIONS: The S3HoCKwave score is easy to understand, has a relatively high predictive value, and allows clinicians to make appropriate treatment selections.

Lack of a bridge between screening and medical management for hypertension: health screening cohort in Japan.

BACKGROUND: Patient journeys for hypertensive individuals after detection at screening have not been well examined in a general population. Thus, we aimed to assess the medical treatment status and subsequent longitudinal changes in blood pressure in a middle-aged Japanese population. METHODS: We conducted a cohort study using a nationwide Japanese health screening cohort, from April 2014 to March 2019. Among health screening participants aged 40-74 years who had not previously received treatment for hypertension, hypertensive patients were newly identified based on screening results, and their medical treatment status for hypertension during the year following their initial screening was assessed. The main outcomes were longitudinal changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) over 4 years after initial screening. RESULTS: Of the 153,523 screening participants (mean age = 49.7 years), 16,720 (10.9%) and 4150 (2.7%) were newly detected as having hypertension, with baseline SBP of 140-159 mmHg (grade 1) and ≥ 160 mmHg (grade 2-3), respectively. Among them, 15.9% of the grade 1 hypertensive participants and 36.3% of the grade 2-3 hypertensive participants started receiving medical treatment during the year following initial screening. A linear generalised estimating equation with propensity score matching showed that receiving medical treatment was associated with 5.77 mmHg lower SBP (95% CI - 6.64 to - 4.90) and 3.82 mmHg lower DBP (95% CI - 4.47 to - 3.16) in the grade 1 hypertensive group, and 14.69 mmHg lower SBP (95% CI - 16.35 to - 13.04) and 8.42 mmHg lower DBP (95% CI - 9.49 to - 7.34) in the grade 2-3 hypertensive group. CONCLUSIONS: Health screenings detected hypertension in a substantial percentage of the middle-aged population in this study. However, detection was often followed by insufficient medical treatment and inappropriate blood pressure management. These findings indicate an inadequate link between health screenings and medical treatments in patients with hypertension.

Effect of Edaravone on Neurological Symptoms in Real-World Patients With Acute Ischemic Stroke.

Background and Purpose- In Japan, nearly half of ischemic stroke patients receive edaravone for acute treatment. The purpose of this study was to assess the effect of edaravone on neurological symptoms in patients with ischemic stroke stratified by stroke subtype. Methods- Study subjects were 61 048 patients aged 18 years or older who were hospitalized ≤14 days after onset of an acute ischemic stroke and were registered in the Japan Stroke Data Bank, a hospital-based multicenter stroke registration database, between June 2001 and July 2013. Patients were stratified according to ischemic stroke subtype (large-artery atherosclerosis, cardioembolism, small-vessel occlusion, and cryptogenic/undetermined) and then divided into 2 groups (edaravone-treated and no edaravone). Neurological symptoms were evaluated using the National Institutes of Health Stroke Scale (NIHSS). The primary outcome was changed in neurological symptoms during the hospital stay (ΔNIHSS=NIHSS score at discharge-NIHSS score at admission). Data were analyzed using multivariate linear regression with inverse probability of treatment weighting after adjusting for the following confounding factors: age, gender, and systolic and diastolic blood pressure at the start of treatment, NIHSS score at admission, time from stroke onset to hospital admission, infarct size, comorbidities, concomitant medication, clinical department, history of smoking, alcohol consumption, and history of stroke. Results- After adjusting for potential confounders, the improvement in NIHSS score from admission to discharge was greater in the edaravone-treated group than in the no edaravone group for all ischemic stroke subtypes (mean [95% CI] difference in ΔNIHSS: -0.46 [-0.75 to -0.16] for large-artery atherosclerosis, -0.64 [-1.09 to -0.2] for cardioembolism, and -0.25 [-0.4 to -0.09] for small-vessel occlusion). Conclusions- For any ischemic stroke subtype, edaravone use (compared with no use) was associated with a greater improvement in neurological symptoms, although the difference was small (<1 point NIHSS) and of limited clinical significance.

Intra-Dialytic Hemoglobin Changes and Cardiovascular Events: A Cohort Study on Dialysis Outcomes and Practice Patterns in Japan.

BACKGROUND: Ultrafiltration during hemodialysis (HD) causes hemoconcentration. Little is known about the relationships between intra-dialytic changes in hemoglobin concentration and cardiovascular events. Thus, this study aimed to elucidate the relationships between intra-dialytic changes in hemoglobin concentration and cardiovascular events among HD patients. METHODS: This prospective cohort study was based on the Japanese Dialysis Outcomes and Practice Pattern Study phases 4 and 5. The predictor was the ratio of post-dialysis hemoglobin concentration to pre-dialysis hemoglobin concentration (post-Hb/pre-Hb) at baseline. The primary outcome was major adverse cardiovascular events (MACEs). Hazard ratios (HRs) were estimated using a Cox model for the association between post-Hb/pre-Hb and MACEs, adjusting for potential confounders. RESULTS: A total of 865 patients were enrolled. During a median follow-up of 2.6 years, 145 (16.8%) patients developed MACEs. Patients were divided into 4 categories according to baseline post-Hb/pre-Hb (<1.0, ≥1.0 to <1.1, ≥1.1 to <1.2, and ≥1.2). The multivariable-adjusted HRs for MACEs were 1.69 (95% CI 1.36-2.10), 1.29 (95% CI 1.10-1.51), and 1.31 (95% CI 1.02-1.68) in patients with post-Hb/pre-Hb ratios of <1.0, ≥1.0 to <1.1, and ≥1.2, respectively, compared with the reference post-Hb/pre-Hb ratio of ≥1.1 to <1.2. Cubic spline analyses revealed a U-shaped association between post-Hb/pre-Hb and MACEs. CONCLUSION: High and low intra-dialytic changes in hemoglobin concentration are associated with a high risk of MACEs in patients undergoing HD.

Dialysate temperature reduction for intradialytic hypotension for people with chronic kidney disease requiring haemodialysis.

BACKGROUND: Intradialytic hypotension (IDH) is a common complication of haemodialysis (HD), and a risk factor of cardiovascular morbidity and death. Several clinical studies suggested that reduction of dialysate temperature, such as fixed reduction of dialysate temperature or isothermal dialysate using a biofeedback system, might improve the IDH rate. OBJECTIVES: This review aimed to evaluate the benefits and harms of dialysate temperature reduction for IDH among patients with chronic kidney disease requiring HD, compared with standard dialysate temperature. SEARCH METHODS: We searched Cochrane Kidney and Transplant's Specialised Register up to 14 May 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov. SELECTION CRITERIA: All randomised controlled trials (RCTs), cross-over RCTs, cluster RCTs and quasi-RCTs were included in the review. DATA COLLECTION AND ANALYSIS: Two authors independently extracted information including participants, interventions, outcomes, methods of the study, and risks of bias. We used a random-effects model to perform quantitative synthesis of the evidence. We assessed the risks of bias for each study using the Cochrane 'Risk of bias' tool. We assessed the certainty of evidence using Grades of Recommendation, Assessment, Development and Evaluation (GRADE). MAIN RESULTS: We included 25 studies (712 participants). Three studies were parallel RCTs and the others were cross-over RCTs. Nineteen studies compared fixed reduction of dialysate temperature (below 36°C) and standard dialysate temperature (37°C to 37.5°C). Most studies were of unclear or high risk of bias. Compared with standard dialysate, it is uncertain whether fixed reduction of dialysate temperature improves IDH rate (8 studies, 153 participants: rate ratio 0.52, 95% CI 0.34 to 0.80; very low certainty evidence); however, it might increase the discomfort rate compared with standard dialysate (4 studies, 161 participants: rate ratio 8.31, 95% CI 1.86 to 37.12; very low certainty evidence). There were no reported dropouts due to adverse events. No study reported death, acute coronary syndrome or stroke.Three studies compared isothermal dialysate and thermoneutral dialysate. Isothermal dialysate might improve the IDH rate compared with thermoneutral dialysate (2 studies, 133 participants: rate ratio 0.68, 95% CI 0.60 to 0.76; I2 = 0%; very low certainty evidence). There were no reports of discomfort rate (1 study) or dropouts due to adverse events (2 studies). No study reported death, acute coronary syndrome or stroke. AUTHORS' CONCLUSIONS: Reduction of dialysate temperature may prevent IDH, but the conclusion is uncertain. Larger studies that measure important outcomes for HD patients are required to assess the effect of reduction of dialysate temperature. Six ongoing studies may provide much-needed high quality evidence in the future.

Effect of Patient Experience on Bypassing a Primary Care Gatekeeper: a Multicenter Prospective Cohort Study in Japan.

BACKGROUND: To discuss how best to implement the gatekeeping functionality of primary care; identifying the factors that cause patients to bypass their primary care gatekeepers when seeking care should be beneficial. OBJECTIVE: To examine the association between patient experience with their primary care physicians and bypassing them to directly obtain care from higher-level healthcare facilities. DESIGN AND METHODS: This prospective cohort study was conducted in 13 primary care clinics in Japan. We assessed patient experience of primary care using the Japanese version of Primary Care Assessment Tool (JPCAT), which comprises six domains: first contact, longitudinality, coordination, comprehensiveness (services available), comprehensiveness (services provided), and community orientation. The primary outcome was the patient bypassing their usual primary care physician to seek care at a hospital, with this occurring at least once in a year. We used a Bayesian hierarchical model to adjust clustering within clinics and individual covariates. KEY RESULTS: Data were analyzed from 205 patients for whom a physician at a clinic served as their usual primary care physician. The patient follow-up rate was 80.1%. After adjustment for patients' sociodemographic and health status characteristics, the JPCAT total score was found to be inversely associated with patient bypass behavior (odds ratio per 1 SD increase, 0.44; 95% credible interval, 0.21-0.88). The results of various sensitivity analyses were consistent with those of the primary analysis. CONCLUSIONS: We found that patient experience of primary care in Japan was inversely associated with bypassing a primary care gatekeeper to seek care at higher-level healthcare facilities, such as hospitals. Our findings suggest that primary care providers' efforts to improve patient experience should help to ensure appropriate use of healthcare services under loosely regulated gatekeeping systems; further studies are warranted.

Salt Intake and All-Cause Mortality in Hemodialysis Patients.

BACKGROUND: Although some clinical practice guidelines regarding hemodialysis recommend salt restriction, few studies have examined the association between salt intake and clinical outcomes in hemodialysis patients. This study aimed to clarify the association between salt intake and mortality in hemodialysis patients. METHODS: This retrospective cohort study was based on the Japanese Society for Dialysis Therapy renal data registry database (2008) and included 88,115 adult patients who had received hemodialysis for at least 2 years. Estimated salt intake was the main predictor and was calculated from intra-dialytic weight loss and pre- and post-dialysis serum sodium levels. Nonlinear logistic regression was used to determine the association between salt intake and mortality, adjusting for potential confounders. The outcomes considered were all-cause mortality and cardiovascular death at 1 year. RESULTS: The median (25-75th percentile) salt intake at baseline was 6.4 (4.6-8.3) g/day. At 1 year, all-cause mortality occurred in 1,845 (2.1%) patients, including 807 cardiovascular deaths. The low salt intake group (< 6 g/day) demonstrated the highest all-cause mortality and cardiovascular deaths. No association was observed between high salt intake, all-cause mortality and cardiovascular deaths. The lowest risk for all-cause mortality and cardiovascular death occurred among patients with an estimated salt intake of 9 g/day. CONCLUSION: Low salt intake, but not high salt intake, was associated with all-cause and cardiovascular mortality in Japanese hemodialysis patients. Further studies to justify including a lower limit of salt intake for hemodialysis patients are suggested.

Social Isolation and Patient Experience in Older Adults.

PURPOSE: Social isolation has been identified as a major health problem, particularly in the elderly. In the present study, we examine the association between social isolation and patient experience in elderly primary care patients. METHODS: This cross-sectional study was conducted in a primary care practice-based research network (28 clinics) in Japan. We assessed social isolation using an abbreviated Lubben Social Network Scale and patient experience of primary care using a Japanese version of the Primary Care Assessment Tool (JPCAT), which comprises 6 domains: first contact, longitudinality, coordination, comprehensiveness (services available), comprehensiveness (services provided), and community orientation. We used a linear mixed effects model to adjust clustering within clinics and individual covariates. RESULTS: Data were analyzed for 465 elderly primary care patients aged ≥65 years. After adjustment for possible confounders and clustering within clinics, social isolation was negatively associated with the JPCAT total score, (mean difference = -3.67; 95% CI, -7.00 to -0.38). Among the JPCAT domain scores, social isolation was significantly associated with longitudinality, comprehensiveness (service provided), and community orientation scores. CONCLUSIONS: Social isolation was associated with negative patient experience in elderly primary care patients. Raising awareness regarding patient social networks among primary care providers and targeted interventions for socially isolated elderly patients aimed at improving the experience of primary care, especially regarding longitudinality, comprehensiveness, and community orientation, may be warranted.

Patient experience of primary care and advance care planning: a multicentre cross-sectional study in Japan.

Background: Advance care planning (ACP) is becoming increasingly important in the primary care setting because of its positive impact on the end-of-life care. Objective: We aimed to investigate the relationship between patient experience of primary care and ACP. Methods: This cross-sectional study was conducted in 28 primary care clinics in Japan. We assessed patient experience of primary care using a Japanese version of Primary Care Assessment Tool (JPCAT), which comprises six domains: first contact, longitudinality, coordination, comprehensiveness (services available), comprehensiveness (services provided) and community orientation. The primary outcome measures were ACP discussion between patients and primary care providers and completion of advance directives (AD). We used a generalized linear mixed model to adjust clustering within clinics and individual covariates. Results: Data were analysed for 535 primary care patients. After adjustment for patients' sociodemographic and health characteristics, the JPCAT total score was found to be significantly associated with ACP discussion [odds ratio (OR) per 1 SD increase = 4.33; 95% confidence interval (CI), 2.53-7.47] but not with completion of AD (OR per 1 SD increase = 1.42; 95% CI, 0.94-2.12). All domains of JPCAT, which represent attributes of primary care, had positive associations with ACP discussion. First contact and comprehensiveness (services provided) domain scores were significantly associated with completion of AD. Conclusions: We found that better patient experience of primary care was strongly associated with ACP discussion. Our findings reinforce the significance of patient experience in primary care as part of quality end-of-life care.

Attributes of primary care in relation to polypharmacy: a multicenter cross-sectional study in Japan.

OBJECTIVE: To investigate the association between attributes of primary care and polypharmacy. DESIGN: Cross-sectional study. SETTING: A primary care practice-based research network in Japan (28 primary care clinics). PARTICIPANTS: Adult outpatients filled out a standardized questionnaire. MAIN OUTCOME MEASURE: Polypharmacy defined as the use of five or more concurrent prescription or over-the-counter medications. METHODS: Attributes of primary care were assessed via patient experience using the Japanese version of Primary Care Assessment Tool (JPCAT). Poisson mixed effects model was used to adjust for clustering within clinics and covariates. RESULTS: Data were analyzed for 544 primary care outpatients. After adjusting for patients' sociodemographic and health characteristics, the JPCAT community orientation score was found to be inversely associated with polypharmacy at the clinic level [risk ratio per 1 standard deviation increase = 0.83; 95% confidence interval (CI), 0.73-0.96; P = 0.008]. Sensitivity analyses using a different definition of polypharmacy showed results similar to those of the primary analyses. CONCLUSIONS: We found that a higher level of community-oriented primary care is associated with a lower prevalence of polypharmacy in outpatients at the clinic level. These findings may be useful in developing community-based interventions to minimize polypharmacy.

Visceral fat level is an independent risk factor for cardiovascular mortality in hemodialysis patients.

BACKGROUND: Obesity is an independent risk factor for morbidity and mortality in cardiovascular diseases not only in the general population, but also in hemodialysis (HD) patients. We previously reported that an increased visceral fat area (VFA) determined using computed tomography (CT) scans was associated with atherosclerosis in HD patients. However, whether a high VFA is associated with increased cardiovascular mortality in HD patients remains unknown. Therefore, we investigated the relationship between VFA and prognosis in HD patients. METHODS: VFA was estimated in 126 patients on maintenance HD using CT scans. These patients were followed for 60 months. RESULTS: Kaplan-Meier analysis revealed that the cardiovascular survival rate was significantly lower in the high-VFA group, with a VFA of 71.5 cm(2) or greater, than in the low-VFA group, with a VFA of less than 71.5cm(2). In univariate Cox proportional hazards analyses, age, albumin, low-density lipoprotein cholesterol, cardio-thoracic ratio and VFA above 71.5 cm(2) were significantly correlated with cardiovascular deaths. In multivariate analyses testing these factors as dependent variables, VFA above 71.5 cm(2) was estimated to be an independent predictor of cardiovascular deaths. CONCLUSION: These results suggest that an increased VFA is a stronger risk factor for cardiovascular deaths in HD patients. Measuring VFA may be recommended for predicting the risk of cardiovascular diseases in HD patients.

Free air on CT and the risk of peritonitis in peritoneal dialysis patients: a retrospective study.

BACKGROUND: Intra-abdominal free air is found frequently in patients undergoing peritoneal dialysis (PD). Some studies have investigated an association between intra-abdominal free air and peritonitis in PD patients. However, most used chest X-rays, which are of limited sensitivity, and the association was not made clear. We conducted a retrospective study of the association between peritonitis and intra-abdominal free air using computed tomography. METHODS: The presence and volume of free air, and its relationship with other variables, were assessed on review of routine examinations in 108 patients. Correlations between the presence of free air and age, duration of PD, continuous ambulatory versus automated PD, presence or absence of a person who assisted in bag changes, exit-site infection, tunnel infection and peritonitis were assessed. RESULTS: Free air was detected in 29 patients (27.1%). The prevalence of peritonitis was higher in the free air (+) group than in the free air (-) group: 1/40.2 patient-months for free air (+) versus 1/96.9 patient-months for free air (-). The risk ratio of free air for peritonitis was 2.41 (95% confidence interval: 2.28-2.55) and was similar when corrected for age, gender, albumin, diabetes mellitus and body mass index. CONCLUSION: Free air is an independent risk factor for peritonitis in PD patients. This suggests that bag change procedures should be re-evaluated, and patients re-educated, when necessary.

Prevalent and new use of common drugs for the incidence of community-acquired acute kidney injury: cohort and case-crossover study.

Although community-acquired acute kidney injury (CA-AKI) represents a significant subset of all AKI incidence, evidence is limited due to the lack of comprehensive data prior to diagnosis. Here, we examined the risk of drug use for CA-AKI by using exhaustive pre-diagnostic prescription data. We included 78,754 working-age healthy individuals who underwent an annual health checkup program. We conducted a cohort study to assess the association between prevalent drug use and subsequent CA-AKI incidence using the Cox proportional hazard model. Subsequently, we conducted a case-crossover study to compare the new drug use in the case period directly before the CA-AKI incidence (- 3 to 0 months) with that in the control period far before the CA-AKI incidence (- 15 to - 12 months and - 9 to - 6 months) using the conditional Poisson regression model. The prevalent use of renin-angiotensin-aldosterone system (RAAS) inhibitors was associated with an increased CA-AKI incidence, but the new use was not. The new use of diuretics, anti-infectious drugs, and contrast medium was also associated with an increased CA-AKI incidence. These results suggest we need to pay attention for the incidence of AKI among the general population taking those common drugs.