Sayaka Shimizu

Majority of systematic reviews published in high-impact journals neglected to register the protocols: a meta-epidemiological study

OBJECTIVES To describe the registration of systematic review (SR) protocols and examine whether or not registration reduced the outcome reporting bias in high-impact journals. STUDY DESIGN AND SETTING We searched MEDLINE via PubMed to identify SRs of randomized controlled trials of interventions. We included SRs published between August 2009 and June 2015 in the 10 general and internal medicinal journals with the highest impact factors in 2013. We examined the proportion of SR protocol registration and investigated the relationship between registration and outcome reporting bias using multivariable logistic regression. RESULTS Among the 284 included reviews, 60 (21%) protocols were registered. The proportion of registration increased from 5.6% in 2009 to 27% in 2015 (P for trend <0.001). Protocol registration was not associated with outcome reporting bias (adjusted odds ratio [OR] 0.85, 95% confidence interval [CI] 0.39-1.86). The association between Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) adherence and protocol registration was not statistically significant (OR 1.09, 95% CI 0.59-2.01). CONCLUSIONS Six years after the launch of the PRISMA statement, the proportion of protocol registration in high-impact journals has increased some but remains low. The present study found no evidence suggesting that protocol registration reduced outcome reporting bias.

Idiosyncratic Liver Injury Induced by Vildagliptin With Successful Switch to Linagliptin in a Hemodialyzed Diabetic Patient

Recently, cases of liver injury associated with dipeptidyl peptidase-4 (DPP-4) inhibitors have been reported (1,2). Some postulate the liver injury is mediated by class effect of DPP-4 inhibitors (1), as DPP-4 is identical to CD26 expressed in lymphocytes and macrophages and DPP-4 inhibitors suppress CD26-induced T-cell activation, thereby contributing to immunomodulation (3). However, no report presents whether liver injury associated with DPP-4 inhibitors is class effect or drug-specific. Here, we report a potential case of idiosyncratic liver injury associated with vildagliptin. A 65-year-old woman receiving hemodialysis due to diabetic nephropathy presented with slowly progressive liver dysfunction. She was treated with insulin (4 units/day), acarbose (150 mg/day), and gliclazide (10 mg/day). With this regimen, her A1C was 7.6% (60 mmol/mol). After confirmation that …

Impact of trajectories of abdominal aortic calcification over 2 years on subsequent mortality: a 10-year longitudinal study

Background Although both the presence and progression over time of vascular calcification have been shown to independently predict cardiovascular disease and mortality in chronic dialysis patients, the impact of the pattern of accumulation of abdominal aortic calcification on mortality has not yet been investigated. Methods We conducted a longitudinal study at a dialysis hospital in Hokkaido, Japan from 2005 to 2014. An abdominal calcification index (ACI) was generated for 396 patients from their annual abdominal computed tomography (CT) scans. The trajectories of ACIs during the first 2 years were classified using group-based trajectory modeling into four groups; stable (29.0%), slow increase (29.2%), rapid nonlinear increase (24.4%) and advanced with slow increase (17.4%). Incidence rates by group of all-cause mortality during the follow-up period (mean of 4.5 years) were investigated using the Cox proportional hazard model. Results Compared with the stable trajectory, both the rapid nonlinear increase and the advanced with slow increase trajectories were associated with an increased risk of death [adjusted hazard ratios (HR) 1.91; 95% confidence interval (CI) 1.02-3.58 and adjusted HR 2.79; 95% CI: 1.44-5.11, respectively]. Sensitivity analyses indicated that ACI trajectories were associated with subsequent mortality, while ACI at individual time points was not. Conclusions Chronic hemodialysis patients with a trajectory of longitudinal high or rapid accumulation of vascular calcification over time were at a higher risk of death. Individual trajectories of vascular calcification may be suggested to allow for more accurate mortality risk calculations than one-time assessment.

Association Between Subjective Sleep Quality and Future Risk of Falls in Older People: Results From LOHAS

Background Inadequate sleep is correlated with morbidity and mortality among older adults. However, the longitudinal relationship between subjective sleep quality and risk of falls in the elderly population remains to be clarified. Methods Study participants were from Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS) sites (1,071 community-dwelling people ≧65 years of age, mean: 71 years). Subjective sleep quality was measured by the Pittsburgh Sleep Quality Index (PSQI). Occurrence of falls (defined as experiencing at least one fall) during the subsequent year was ascertained by a self-reported questionnaire. Results Mean global PSQI score was 4.3 (SD 3.2), with 28.9% of participants rating their sleep quality as poor (PSQI > 5). A total of 210 participants (19.6%) fell at least once in the year following sleep examination. Multivariable analysis revealed that participants reporting worse subjective sleep quality had significantly higher odds of experiencing falls during the 1-year follow-up period (adjusted odds ratio [AOR] = 1.50 for each three-point increase in global PSQI score; 95% confidence interval [CI] = 1.20, 1.89). Participants in the highest global PSQI score (PSQI > 5) quartile had significantly increased odds of experiencing falls compared to those in the lowest global score quartile (PSQI < 2; AOR = 2.14; 95% CI = 1.09, 4.22). This association was similarly significant in subgroup analyses for older men and women, nonusers of sleep medication, and those without a history of falls at baseline. Conclusion Subjective poor sleep quality, as measured by the PSQI, is longitudinally associated with greater risk of experiencing falls in community-dwelling older adults.

Association between spinal immobilization and survival at discharge for on-scene blunt traumatic cardiac arrest: A nationwide retrospective cohort study

INTRODUCTION Spinal immobilization has been indicated for all blunt trauma patients suspected of having cervical spine injury. However, for traumatic cardiac arrest (TCA) patients, rapid transportation without compromising potentially reversible causes is necessary. Our objective was to investigate the temporal trend of spinal immobilization for TCA patients and to examine the association between spinal immobilization and survival. METHODS We conducted a retrospective cohort study using the Japan Trauma Data Bank 2004-2015 registry data. Our study population consisted of adult blunt TCA patients encountered at the scene of a trauma. The primary outcome was the survival proportion at hospital discharge, and the secondary outcome was the proportion achieving return of spontaneous circulation (ROSC). We examined the association between spinal immobilization and these outcomes using a logistic regression model based on imputed data sets with the multiple imputation method to account for missing data. RESULTS Among 4313 patients who met the inclusion criteria, 3307 (76.7%) were immobilized. The proportion of patients that underwent spinal immobilization gradually decreased from 82.7% in 2004-2006 to 74.0% in 2013-2015. 1.0% of immobilized and 0.9% of non-immobilized patients had severe cervical spine injury. Spinal immobilization was significantly associated with lower survival at discharge (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.42 to 0.98) and ROSC by admission (OR, 0.48; 95%CI, 0.27 to 0.87). There was no significant sub-group difference of the association between spinal immobilization and survival at discharge by patients with or without cervical spine injury (p for interaction 0.73). CONCLUSION Spinal immobilization is widely used even for blunt TCA patients, even though it is associated with a lower rate of survival at discharge and ROSC by admission. According to these results, we suggest that spinal immobilization should not be routinely recommended for all blunt TCA patients.

Computed tomography during initial management and mortality among hemodynamically unstable blunt trauma patients: a nationwide retrospective cohort study

BackgroundAlthough many hemodynamically unstable trauma patients undergo computed tomography (CT) to identify a source of bleeding, this practice is currently only recommended by a few guidelines. To clarify whether CT has harmful effects among these patients, we examined the association between CT during initial management and mortality among unstable blunt trauma patients.MethodsThis was a retrospective cohort study based on Japan Trauma Data Bank 2004–2014 registry data. Study population was adult blunt trauma patients with hypotension on arrival. The primary outcome was the in-hospital mortality. Two types of analyses were performed to adjust for confounding factors including propensity score inverse probability of treatment weighted (IPTW) and instrumental variable (IV) analysis.ResultsAmong 5,809 patients who met inclusion criteria, 5,352 (92.1%) underwent CT. The No CT group was more likely to have severe physiological conditions and lower probability of survival than those of the CT group. In IPTW analysis adjusting for measured confounders, we found a significant protective effect of undergoing CT on in-hospital mortality (excess deaths: −20.6 per 100 patients, 95% CI −26.2 to −14.9). In IV analysis adjusting both for measured and unmeasured confounders, the association between CT and mortality was not statistically significant (excess deaths: −4.1 per 100 patients, 95% CI −23.1 to 14.8).DiscussionWe did not find clinically meaningful harmful effect of CT on survival for unstable blunt trauma patients even after adjusting both for measured and unmeasured confounders.Conclusions Our results did not support the recommendation of current guideline. We suggest physicians should consider CT as one of the diagnostic options even when patients are unstable.

Effects of Higher Quality of Care on Initiation of Long-term Dialysis in Patients With CKD and Diabetes

BACKGROUND The burden of diabetes-related chronic kidney disease (CKD) on individuals and society is increasing, shifting attention toward improving the quality of care for patients with CKD and diabetes. We assessed the quality of CKD care and its association with long-term dialysis, acute kidney injury (AKI), and death. STUDY DESIGN Retrospective cohort study (2004-2011). SETTING & PARTICIPANTS Adults in Taiwan with incident CKD enrolled in the Longitudinal Cohort of Diabetes Patients. PREDICTORS 3 CKD-care quality indicators based on medical and pharmacy claims data were studied: prescription of renin-angiotensin system inhibitors, testing for proteinuria, and nutritional guidance. Each was examined individually, and all were summed into an overall quality score. OUTCOMES The primary outcome was initiation of long-term dialysis therapy. Secondary outcomes were hospitalization due to AKI and death from any cause. MEASUREMENTS Using instrumental variables related to the quality indicators to minimize both unmeasured and measured confounding, we fit a 2-stage residual inclusion model to estimate HRs and 95% CIs for each outcome. RESULTS Among the 63,260 patients enrolled, 43.9% were prescribed renin-angiotensin system inhibitors, 60.6% were tested for proteinuria, and 13.4% received nutritional guidance. During a median follow-up of 37.9 months, 1,471 patients started long-term dialysis therapy, 2,739 patients were hospitalized due to AKI, and 4,407 patients died. Higher overall quality scores were associated with lower hazards for long-term dialysis in instrumental variable analyses (HR of 0.62 [95% CI, 0.40-0.98] per 1-point greater score) and hospitalization due to AKI (HR of 0.69 [95% CI, 0.50-0.96] per 1-point greater score). The hazard for all-cause death was nonsignificantly lower (HR of 0.80 [95% CI, 0.62-1.03] per 1-point greater score). LIMITATIONS Potential misclassification and uncontrolled confounding by indication. CONCLUSIONS Our findings suggest potential opportunities to improve long-term outcomes among patients with diabetes and CKD by improving the quality of their CKD care.

Concerns about study on maternal H1N1 influenza vaccination and offspring mortality

We have three concerns about Ludvigsson and colleagues’ article on the association between maternal influenza A(H1N1)pdm09 vaccination during pregnancy and mortality in the offspring.1 Firstly, the authors defined exposure as vaccination during pregnancy. Accordingly, women who were vaccinated just before pregnancy were …

Increased Mortality Rate after Hospitalization Among Chronic Hemodialysis Patients: A Prospective Cohort Study

Background/Aims: Hemodialysis patients are at high risk of hospitalization and their condition may worsen with repeated hospitalization. The aim of this study was to evaluate the impact of the cumulative number of hospitalizations on post-discharge mortality. Methods: This study was a prospective cohort study. We examined 3,359 adult patients on hemodialysis for at least 90 days who participated in the Japanese Dialysis Outcomes and Practice Patterns Study phases 3 and 4 (2005–2012). The patients hospitalized within 3 months before enrollment were excluded. The main exposure was the time-varying cumulative number of hospitalizations during the follow-up period. Hazard ratios (HRs) for all-cause mortality rate after discharge were estimated by time-dependent Cox regressions after adjusting for potential confounders. Results: The median follow-up time was 2.7 years, and 873 (26%) patients experienced at least 1 hospitalization during follow-up. The hospitalization rate was 0.23 per person-year and the mortality rate was 0.036 per person-year. The HR and 95% CI for post-discharge mortality increased as the cumulative number of hospitalizations increased: once, 1.41 (0.99–2.00); and twice or more, 2.27 (1.59–3.23). The cause-specific hospitalization categories, “infectious disease” and “cancer,” affected post-discharge mortality HRs in a similar manner: 2.41(1.32–4.41) and 2.70 (1.23–5.93), respectively. Conclusion: A higher cumulative number of hospitalizations is associated with increased post-discharge mortality in chronic hemodialysis patients. The cause-specific hospitalizations category of “infectious disease” showed an impact on mortality similar to that of hospitalization for “cancer.” Therefore, physicians should pay more attention to reducing preventable hospitalizations.

Development and validation of a prediction model for loss of physical function in elderly hemodialysis patients

Abstract Background Among aging hemodialysis patients, loss of physical function has become a major issue. We developed and validated a model of predicting loss of physical function among elderly hemodialysis patients. Methods We conducted a cohort study involving maintenance hemodialysis patients  ≥65 years of age from the Dialysis Outcomes and Practice Pattern Study in Japan. The derivation cohort included 593 early phase (1996–2004) patients and the temporal validation cohort included 447 late-phase (2005–12) patients. The main outcome was the incidence of loss of physical function, defined as the 12-item Short Form Health Survey physical function score decreasing to 0 within a year. Using backward stepwise logistic regression by Akaike’s Information Criteria, six predictors (age, gender, dementia, mental health, moderate activity and ascending stairs) were selected for the final model. Points were assigned based on the regression coefficients and the total score was calculated by summing the points for each predictor. Results In total, 65 (11.0%) and 53 (11.9%) hemodialysis patients lost their physical function within 1 year in the derivation and validation cohorts, respectively. This model has good predictive performance quantified by both discrimination and calibration. The proportion of the loss of physical function increased sequentially through low-, middle-, and high-score categories based on the model (2.5%, 11.7% and 22.3% in the validation cohort, respectively). The loss of physical function was strongly associated with 1-year mortality [adjusted odds ratio 2.48 (95% confidence interval 1.26–4.91)]. Conclusions We developed and validated a risk prediction model with good predictive performance for loss of physical function in elderly hemodialysis patients. Our simple prediction model may help physicians and patients make more informed decisions for healthy longevity.