A Study on the Bias-Correction Effect of the AIC for Selecting Variables in Normal Multivariate Linear Regression Models under Model Misspecification

Abstract By numerically comparing a variable-selection method using the crude AIC with those using the bias-corrected AICs, we find out knowledge about what kind of bias correction gives a positive effect to variable selection under model misspecification. Actually, since it can be proved theoretically that all the variable-selection methods considered in this paper asymptotically choose the same model as the best model, we conduct numerical examinations using small and moderate sample sizes. Our results show that bias correction under assumption that the mean structure is misspecified has a better effect on variable selection than that under the assumption that the distribution of the model is misspecified

Risk of higher dose methotrexate for renal impairment in patients with rheumatoid arthritis

Renal impairment is a major concern in patients taking high-dose methotrexate (MTX) for malignancy, but it has not been fully explored in rheumatoid arthritis (RA) patients taking low-dose MTX. This study aimed to elucidate the dose-dependent effects of MTX on the renal function of patients with RA. We retrospectively reviewed 502 consecutive RA patients who were prescribed MTX for >= 1 year at Okayama University Hospital between 2006 and 2018. The primary outcome was the change in estimated glomerular filtration rate (eGFR) over 1 year. The association between MTX dosage (= 12 mg/week) and the change in eGFR was evaluated using multiple linear regression analysis with adjustment for possible confounding factors including age, sex, disease duration, body weight, comorbidity, baseline eGFR, concomitant treatment, and disease activity. Mean patient age was 63 years; 394 (78%) were female. Median disease duration was 77 months, while mean MTX dosage was 8.6 mg/week. The last 1-year change of eGFR (mean +/- SD) in patients treated with MTX= 12 mg/week (n=97) decreased by 0.2 +/- 7.3, 0.6 +/- 8.6, and 4.5 +/- 7.9 mL/min/1.73 m(2)/year, respectively (p= 12 mg/week was still correlated with a decrease in 1-year eGFR (beta-coefficient:-2.5; 95% confidence interval,-4.3 to-0.6; p=0.0089) in contrast to MTX 8-12 mg/week. Careful monitoring of renal function is required in patients with MTX >= 12 mg/week over the course of RA treatment regardless of disease duration

Association of explanatory histological findings and urinary protein and serum creatinine levels at renal biopsy in lupus nephritis: a cross-sectional study

Background The aim of the present study was to evaluate the association between the histology of active and chronic lesions and urinary protein and serum creatinine (SCr) levels, as common clinical endpoints in clinical trials for lupus nephritis (LN). Methods In total, 119 patients diagnosed with LN class III, IV, and V, as defined by the International Society of Nephrology/Renal Pathology Society, between 1990 and 2015, were enrolled in the present study. Multiple regression analysis was performed to explore semi-quantitative histological variables associated with urinary protein and SCr levels. Results The mean age of the enrolled patients was 45 years, and 79% were female. The mean SCr and mean urinary protein levels at the time of renal biopsy were 0.87 mg/dl and 3.00 g/gCr, respectively. Class IV (71%) was the most common type of LN followed by class III (17%), and class V (13%). Multicollinearity was confirmed between monocellular infiltration (variance inflation factor [VIF] = 10.22) and interstitial fibrosis (VIF = 10.29), and between karyorrhexis (VIF = 4.14) and fibrinoid necrosis (VIF = 4.29). Fibrinoid necrosis and monocellular infiltration were subsequently excluded, and multiple regression analysis revealed that only the urinary protein level was correlated with wire loop lesions (β-coefficient [β]: 1.09 and confidence interval [CI]: 0.35 to 1.83), and that the SCr level was correlated with glomerular sclerosis (β: 1.08 and CI: 0.43 to 1.74). Conclusion As urinary protein and SCr levels were not quantitatively associated with active lesions, they may not accurately reflect the response to remission induction therapy in patients with LN

Risk Factors for Chronic Damage Accumulation Across Different Onset Eras in Systemic Lupus Erythematosus: A Cross-sectional Analysis of a Lupus Registry of Nationwide Institutions (LUNA)

Chronic damage accumulation affects not only mortality but also quality of life in patients with systemic lupus erythematosus (SLE). Risk factors for chronic damage were explored in SLE through different onset eras. Two hundred forty-five patients at Okayama University Hospital and Showa University Hospital were divided into three groups based on the onset era: a past-onset group (onset before 1995; n=83), middle-onset group (1996-2009; n=88), and recent-onset group (after 2010; n=74). The mean Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) score as an index of chronic damage was 1.93, 1.24, and 0.53 in the past-, middle-, and recent-onset groups, respectively. In the pastonset group, the total SDI score was significantly associated with glucocorticoid monotherapy by linear regression analysis (β-coefficient [β]=0.63; 95% confidence interval [CI], 0.21-1.05) and C-reactive protein levels (β=0.67; 95% CI, 0.27-1.07). In the middle-onset group, the total SDI score was significantly associated with the SLE Disease Activity Index at registration (β=0.09; 95% CI, 0.03-0.12). Reducing the accumulation of chronic damage in SLE patients might be possible with the concomitant use of immunosuppressants and tight control of disease activity

Association of glucocorticoid doses and emotional health in lupus low disease activity state (LLDAS): a cross-sectional study

Background While survival of systemic lupus erythematosus (SLE) patients has improved substantially, problems remain in the management of their emotional health. Medium to high-dose glucocorticoid doses are known to worsen emotional health; the effect is unclear among patients receiving relatively low-dose glucocorticoids. This study aims to investigate the association between low glucocorticoid doses and emotional health in lupus low disease activity state (LLDAS). Methods This cross-sectional study drew on data from SLE patients in 10 Japanese institutions. The participants were adult patients with SLE duration of >= 1 year who met LLDAS criteria at the study visit from April 2018 through September 2019. The exposure was the daily glucocorticoid dose (mg oral prednisolone). The outcome was the emotional health score of the lupus patient-reported outcome scale (range: 0 to 100). Multiple linear regression analysis was performed with adjustment for confounders including disease-related damage, activity, and psychotropic drug use. Results Of 192 patients enrolled, 175 were included in the analysis. Their characteristics were as follows: female, 89.7%; median age, 47 years (interquartile range (IQR): 37.0, 61.0). Median glucocorticoid dose was 4.0 mg (IQR 2.0, 5.0), and median emotional health score 79.2 (IQR 58.3, 91.7). Multiple linear regression analysis showed daily glucocorticoid doses to be associated with worse emotional health (beta coefficient = - 2.54 [95% confidence interval - 4.48 to - 0.60], P = 0.01). Conclusions Daily glucocorticoid doses were inversely associated with emotional health among SLE patients in LLDAS. Further studies are needed to determine whether glucocorticoid tapering leads to clinically significant improvements in emotional health

高齢者施設に勤務する介護福祉士による介護評価の分析

研究ノート介護福祉士は生活支援を通して人権擁護を目指すことが求められているが、人権擁護は抽象的な概念であるがゆえに意識が曖昧になりがちである。そこで、高齢者施設に勤務する介護福祉士に対して、人権の要素に関わる日常生活の介護評価を調査し、そこから高齢者施設の介護に関する課題について分析を行った。直接的な介護場面での「残存能力の活用」「清潔の保持」「安全面への配慮」については「できている」との評価が6割を超えた。しかし、「自己決定」「自己選択」「自立」に対し「できていない」と評価した施設が3割から8割を超える結果となった

Demand for pneumococcal vaccination under subsidy program for the elderly in Japan

Abstract Background Vaccination programs often organize subsidies and public relations in order to obtain high uptake rates and coverage. However, effects of subsidies and public relations have not been studied well in the literature. In this study, the demand function of pneumococcal vaccination among the elderly in Japan is estimated, incorporating effects of public relations and subsidy. Methods Using a data from a questionnaire survey sent to municipalities, the varying and constant elasticity models were applied to estimate the demand function. The response variable is the uptake rate. Explanatory variables are: subsidy supported shot price, operating years of the program, target population size for vaccination, shot location intensity, income and various public relations tools. The best model is selected by c-AIC, and varying and constant price elasticities are calculated from estimation results. Results The vaccine uptake rate and the shot price have a negative relation. From the results of varying price elasticity, the demand for vaccination is elastic at municipalities with a shot price higher than 3,708 JPY (35.7 USD). Effects of public relations on the uptake rate are not found. Conclusions It can be suggested that municipalities with a shot price higher than 3,708 JPY (35.7 USD) could subsidize more and reduce price to increase the demand for vaccination. Effects of public relations are not confirmed in this study, probably due to measurement errors of variables used for public relations, and studies at micro level exploring individual’s response to public relations would be required.</p

「国民生活基礎調査」データに基づく居宅介護サービス利用に関する多変量プロビット分析

要旨あり研究ノー